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7428_FCV.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) KINETRA® Dual Program Neurostimulator for Deep Brain Stimulation Technical Manual Rx Only 220822001 Rev X Medtronic Confidential package_R00a 7428 7428_FCV.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) 220822001 Rev X Medtronic Confidential package_R00a 7428_ENtpg.fm 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) KINETRA® Technical Manual Model 7428 220822001 Rev X Medtronic Confidential package_R00a 7428_ENtpg.fm 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) The following are trademarks of Medtronic: Access™, Activa®, DBS™, Itrel®, Kinetra®, Medtronic®, MemoryMod®, SoftStart™, N’Vision™, and Soletra™. 220822001 Rev X Medtronic Confidential package_R00a 7428_ENTOC.fm 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential package_R00a Table of Contents Overview of Manual 5 System Description 6 Indications 6 Contraindications 7 Warnings 8 Precautions 10 Physician Training 10 Storage and Sterilization 10 System and Therapy 10 Implantation/Explantation 12 Electromagnetic Interference (EMI) 14 Medical Environment 15 Home or Occupational Environment 16 Clinical Studies and Adverse Events 18 Individualization of Treatment 18 Resterilization 18 Directions for Use 20 Neurostimulator Implantation or Replacement 20 Tunneling to the Neurostimulator Site 21 Making the Lead-Extension Connection 21 Making the Extension-Neurostimulator Connection 21 Explant Disposition 31 Environmental Problems 31 Handling and Storage 34 Patient Registration 34 Physician Training Information 35 Patient Counseling Information 36 Theft Detectors and Screening Devices 36 3 220822001 Rev X 7428_ENTOC.fm 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential package_R00a Component Manipulation by Patient 37 Kinetra Patient Eligibility 38 Rate Control 38 Screening for Patient Eligibility 38 Detailed Device Description 40 General Description 40 Postoperative Patient Management 45 Programming Stimulation Parameters 49 Electrode Programming Configurations 53 Test Stimulation 56 Specifications and Features 56 How Supplied 63 Appendix A: Battery Longevity Reference Information Tips for Maximizing Battery Life 64 Estimating Battery Life Prior to Neurostimulator Internalization 64 Battery Longevity Worksheet 68 Appendix B: MRI and Activa Therapy 74 Introduction 74 General Information on MRI 77 MRI Interactions with Implanted Activa Systems 78 MRI Procedure 79 Glossary 85 Special Notice 86 4 220822001 Rev X 64 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Overview of Manual Overview of Manual This manual provides information on the Kinetra neurostimulator, a component of the Activa System for deep brain stimulation. The manual describes some items to discuss with your patient, and explains how to register the patient’s device. You will also find instructions for handling, storing, implanting, replacing, and explanting the neurostimulator. General resterilization guidelines are also provided for the new neurostimulator. The manual is divided into the following sections: ■ System Description ■ Indications ■ Contraindications ■ Warnings ■ Precautions ■ Adverse Events ■ Clinical Studies ■ Individualization of Treatment ■ Directions for Use ■ Physician Training Information ■ Patient Counseling Information ■ Detailed Device Description ■ How Supplied ■ References ■ Glossary ■ Special Notice 5 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a System Description System Description The Medtronic Activa System is an implantable, multiprogrammable system that delivers electrical stimulation to selected areas of the brain. The dual program Model 7428 Kinetra Neurostimulator generates electrical signals that are transmitted to the brain. These signals are delivered from the neurostimulator to the brain via the Model 7482 DBS Extension and either the Model 3387 DBS Lead or the Model 3389 DBS Lead. These components comprise the implantable portion of the Activa System. The neurostimulator consists of electronic circuitry and a battery, which are hermetically sealed in a titanium case. The operation of the neurostimulator is supported by a clinician programmer, a therapy controller, and a control magnet. For a complete list of model numbers and components compatible with the Kinetra Neurostimulator, see the Activa System Components Sheet packaged with this manual in the neurostimulator shelf box. Indications1 Bilateral stimulation of the internal globus pallidus (GPi) or the subthalamic nucleus (STN) using Medtronic Activa Parkinson’s Control Therapy is indicated for adjunctive therapy in reducing some of the symptoms of advanced, levodopa-responsive Parkinson’s disease that are not adequately controlled with medication. 1 The dual program Kinetra Model 7428 neurostimulator is not approved for Tremor Control Therapy since only unilateral stimulation is aprpoved for Tremor Control Therapy. 6 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Contraindications Contraindications Implantation of an Activa Brain Stimulation System is contraindicated for: ■ Patients exposed to diathermy. Do not use shortwave diathermy, microwave diathermy or therapeutic ultrasound diathermy (all now referred to as diathermy) on patients implanted with a neurostimulation system. Energy from diathermy can be transferred through the implanted system and can cause tissue damage at the location of the implanted electrodes, resulting in severe injury or death. Diathermy is further prohibited because it can also damage the neurostimulation system components resulting in loss of therapy, requiring additional surgery for system explantation and replacement. Injury or damage can occur during diathermy treatment whether the neurostimulation system is turned “on” or “off.” Advise your patients to inform all their health care professionals that they should not be exposed to diathermy treatment. ■ Patients who will be exposed to Magnetic Resonance Imaging (MRI) using a full body transmit radio-frequency (RF) coil, a receive-only head coil, or a head transmit coil that extends over the chest area. Performing MRI with this equipment can cause tissue lesions from component heating, especially at the lead electrodes, resulting in serious and permanent injury including coma, paralysis or death. Refer to “Appendix B: MRI and Activa Therapy” on page 74 for comprehensive safety information and instructions. ■ Patients for whom test stimulation is unsuccessful. ■ Patients who are unable to properly operate the brain stimulator. 7 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Warnings Warnings Coagulopathies – Use extreme care with lead implantation in patients with a heightened risk of intracranial hemorrhage. Physicians should consider underlying factors, such as previous neurological injury, or prescribed medications (anticoagulants), that may predispose a patient to the risk of bleeding. Avoid Excessive Stimulation – There is a potential risk of brain tissue damage for stimulation parameter settings of high amplitudes and wide pulse widths. The Activa System is capable of parameter settings out of the range of those used in the clinical studies. Suppression of symptoms should occur at amplitudes of 1 to 3.5 V, pulse widths of 60 to 120 µsec, and rates of 130 to 185 Hz. Higher amplitudes and pulse widths may indicate a system problem or less than optimal lead placement. Parameter values exceeding the recommended output settings should only be programmed with due consideration of the warnings concerning charge densities described in “Programming Stimulation Parameters” on page 49. If programming of stimulation parameters exceeds charge density limits, the following programmer warning appears: WARNING: CHARGE DENSITY MAY BE HIGH ENOUGH TO CAUSE TISSUE DAMAGE. The use of rates less than 30 pps may “drive” tremor, i.e., cause it to occur at the same frequency as the programmed frequency. For this reason, rates should not be programmed below 30 pps. Case Damage – If the neurostimulator case is ruptured or pierced after implant due to outside forces, severe burns could result from exposure to battery chemicals. 8 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Warnings Placement of Lead-Extension Connector in Neck – Do not place the lead-extension connector in the soft tissues of the neck. Placement in this location has been associated with an increased incidence of lead fracture. Theft Detectors and Screening Devices – Theft detectors found in retail stores, public libraries, etc., and airport/security screening devices may cause the stimulation power source of an implantable neurostimulation system to switch On or Off1. It is also possible that sensitive patients, or those with low stimulation thresholds, may experience a momentary increase in their perceived stimulation. For other indications, higher levels of stimulation have been described as uncomfortable (“jolting” or “shocking”) by some patients as they pass through these devices. Refer to “Patient Counseling Information” on page 36 for more information. Replacement Procedure – Do not replace two Soletra Model 7426 Neurostimulators with one Kinetra Model 7428 Neurostimulator unless retunneling is performed so both lead-extensions are on the same side of the body. Otherwise, the “looped” configuration formed by the lead-extensions increases the potential for electromagnetic interference (EMI) effects. Magnetic Resonance Imaging – Do not conduct an MRI examination on a patient with any implanted Activa System component until you read and fully understand all MRI information in this manual. Do not conduct an MRI examination at parameters other than those described in this guideline. Failure to follow all warnings and guidelines related to MRI can result in serious and permanent injury including coma, paralysis, or death. Refer to “Appendix B: MRI and Activa Therapy” on page 74 for comprehensive safety information and instructions. 1 Unexpected On/Off switching of the Kinetra Model 7428 Neurostimulator, as described throughout the Warnings and Precautions sections of this manual, may be avoided by disabling the magnet control circuit with the clinician programmer software. If the magnet control circuit is disabled, patients will require a Model 7436 Therapy Controller to turn their therapy On or Off. Refer to “Control Magnet” on page 44. 9 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Precautions Physician Training Implanting Physicians – Implanting physicians should be experienced in stereotactic and functional neurosurgery. Refer to “Physician Training Information” on page 35 in this manual for further information. Prescribing Physicians – Prescribing physicians should be experienced in the diagnosis and treatment of movement disorders and should be familiar with the use of the Activa System. Storage and Sterilization Resterilization Considerations – Refer to “Resterilization” on page 18 for further information. Storage Temperature – Store the Model 7428 Neurostimulator between 0° F (-18° C) and 131° F (55° C). Temperatures outside this range can damage components. System and Therapy Battery Longevity and Brain Target Selection – Stimulation settings for systems implanted in the internal Globus Pallidus (GPi) may be higher than stimulation settings for systems implanted in the Subthalmic Nucleus (STN). Consequently, systems implanted in the GPi may have shorter battery life than systems implanted in the STN. Component Failures – The Activa System may unexpectedly cease to function due to battery depletion or other causes. These events, which can include electrical short or open circuits, conductor (wire) fracture, and insulation breaches, cannot be predicted. The patient’s disease symptoms will return if the device ceases to function. Components – The use of non-Medtronic components with this system may result in damage to Medtronic components, loss of stimulation, or patient injury. 10 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Inadvertent Programming – If more than one neurostimulator is implanted, then the potential for unintentional programming changes to the other neurostimulator exists. If two neurostimulators are implanted, they must be implanted at least 8 inches apart to minimize interference. Verify final programmed parameters by reviewing both devices at the conclusion of any programming session. Lead Materials – The polyurethane tubing of the lead may release neurotoxic or carcinogenic compounds. Data are insufficient to assess the likelihood of these effects occurring in patients who receive the device. Long-Term Safety and Effectiveness of Activa Therapy – The long-term safety and effectiveness of Activa Therapy has not been established. Use in Specific Populations – The safety and effectiveness of this therapy has not been established for the following: ■ Patients with neurological disease origins other than idiopathic Parkinson’s disease ■ Patients with a previous surgical ablation procedure ■ Patients who are pregnant ■ Patients under the age of 18 years ■ Patients over the age of 75 years ■ Patients with dementia ■ Patients with coagulopathies ■ Patients with moderate to severe depression 11 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Implantation/Explantation Body Fluids – Do not resterilize any system component after exposure to body fluids. Component Disposal – If explanting an Activa System component, please remember the following guidelines: ■ Do not incinerate or cremate the neurostimulator; explosion can result if a neurostimulator is subjected to incineration or cremation temperatures. ■ Return all explanted components to Medtronic for analysis and safe disposal. Connections – Wipe off any body fluids on the extension or lead contacts or connector before connecting. Contamination of connections can cause intermittent stimulation or shorts in the neurostimulation circuit. Connector Block Setscrews – Limit counter-clockwise rotations of neurostimulator setscrews. Rotate enough to provide an unobstructed pathway for the extension connector pins. Too many counter-clockwise rotations may disengage the setscrew from the connector block. Etched Identification – Place the neurostimulator away from bony structures and with the etched identification side facing outward, away from muscle tissue to minimize pain at the neurostimulator site. This also helps to minimize the possibility of skeletal muscle stimulation, which may be perceived by the patient as twitching or burning. Excess Extension Wire – Do not place any excess extension wire on top of the neurostimulator’s front side (printed side). Wrap any excess extension wire around the perimeter (Figure 1). This avoids any increase in subcutaneous pocket depth, helps minimize potential damage during neurostimulator replacement surgery, and helps minimize potential kinking of the extension wire. 12 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Figure 1. Wrap excess wire around the perimeter of the neurostimulator. Handling Components – Handle the implanted components of this system with extreme care. These components may be nicked, cut, or damaged by excessive traction or sharp instruments and may require surgical replacement. ■ Do not bend, kink, or stretch the lead body whether or not the stylet is in place. Do not bend or kink the tungsten stylet. ■ Do not tie a suture directly to the extension or lead body. Use the burr hole cap and ring provided by Medtronic to secure the lead in place. ■ When handling the lead with forceps, use only a rubber-tipped bayonet forceps. Hex Wrench – Do not overtighten setscrews when using the hex wrench. Excessive torque on setscrews may damage lead contacts. Verify that the sealing grommet has closed on the neurostimulator. Implant Considerations – Do not implant a component of the system when: ■ The storage package has been pierced or altered; or if the component shows signs of damage; or ■ The “Use By” date has expired, because this can adversely affect storage package sterility. 13 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Multiple Implants – The long-term safety associated with leads left in place without use, replacement of leads, multiple implants into the target structure, and lead explant is unknown. Percutaneous Extension Setscrew Connector – If resistance is still felt when removing lead from the percutaneous extension setscrew connector, loosen the setscrews slightly to ensure that they clear the lead contacts. Avoid disengaging the setscrews. Inspect the lead contacts for damage (flattening or stretching of the lead) if resistance was felt prior to removal. Percutaneous Extension Severing – When severing the percutaneous extension, use gentle traction on the extension to avoid dislodging the lead. Percutaneous Extension Suture Removal – Do not cut near the lead when removing sutures from the percutaneous extension. Cutting the lead’s insulation can result in loss of stimulation and the lead’s failure. Sutures – Do not draw the suture too tightly because damage may occur to the connector boot or to the extension or lead. Torque Wrench – To prevent undertightening the neurostimulator setscrews, do not use the torque wrench from the extension kit. Undertightening may result in insufficient electrical contact within the connector block, which may cause intermittent stimulation. Electromagnetic Interference (EMI) Electromagnetic interference is a field (electrical, magnetic or a combination of both) that is generated by various medical or environmental devices. These medical and environmental (home, occupational, and other) devices may generate enough interference to change the parameters of a neurostimulator; turn a neurostimulator off and on, or cause a neurostimulator to surge, shock, or jolt the patient. 14 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions In addition, it is possible for the extension, lead, or both to “pick up” electromagnetic interference and deliver an excess voltage, which can in turn deliver an excessive amount of heat to the brain. Refer to the sections that follow for guidelines on the interaction of electromagnetic interference and an implanted Activa System. Medical Environment Most routine diagnostic procedures, such as fluoroscopy and x-rays, are not expected to affect system operation. However, because of higher energy levels, sources such as transmitting antennas found on various diagnostic and therapeutic equipment may interfere with the Activa System. Effects on Other Medical Devices – The Activa System may affect the operation of other implanted devices, such as cardiac pacemakers and implantable defibrillators. Possible effects include sensing problems and inappropriate device responses. If the patient requires concurrent implantable pacemaker and/or defibrillator therapy, careful programming of each system may be necessary to optimize the patient’s benefit from each device. Electrocautery – Electrocautery can damage the lead, the extension, or both. It can also cause temporary suppression of neurostimulator output and/or reprogramming of the neurostimulator. If use of electrocautery is necessary, the current path (ground plate) should be kept as far away from the neurostimulator, extension, and lead as possible, and use of bipolar electrocautery is recommended. External Defibrillators – If a patient requires external defibrillation, the first consideration should be patient survival. Safety for use of external defibrillatory discharges on patients with neurostimulation systems has not been established. External defibrillation may damage a neurostimulator. If external defibrillation is necessary, follow these precautions to minimize current flowing through the neurostimulator and lead system: 15 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions ■ Position defibrillation paddles as far from the neurostimulator as possible. ■ Position defibrillation paddles perpendicular to the implanted neurostimulator-lead system. ■ Use the lowest clinically appropriate energy output (watt seconds). ■ Confirm neurostimulation system function following any external defibrillation. High Radiation Sources – High radiation sources, such as cobalt 60 or gamma radiation, should not be directed at the neurostimulator. If a patient requires radiation therapy in the vicinity of the neurostimulator, place lead shielding over the device to prevent radiation damage. Lithotripsy – Use of high output ultrasonic devices, such as an electrohydraulic lithotriptor, is not recommended for patients with an implanted neurostimulation system. While there is no danger to the patient, exposure to high output ultrasonic frequencies may result in damage to the neurostimulator circuitry. If lithotripsy must be used, do not focus the beam near the neurostimulator. Psychotherapeutic Procedures – The safety of psychotherapeutic procedures using equipment that generates electromagnetic interference (e.g., electroshock therapy, transcranial magnetic stimulation) has not been established. Home or Occupational Environment Home Appliances – Home appliances that are in good working order and properly grounded do not usually produce enough electromagnetic interference (EMI) to interfere with neurostimulator operation. However, items with magnets (e.g., stereo speakers, refrigerators, freezers, power tools) may cause the neurostimulator to switch On or Off. 16 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Precautions Occupational Environments – Commercial electrical equipment (arc welders, induction furnaces, resistance welders), communication equipment (microwave transmitters, linear power amplifiers, high-power amateur transmitters), and high voltage power lines may generate enough electromagnetic interference (EMI) to interfere with neurostimulator operation if approached too closely. Patient Activities/Environmental Precautions – Patients should exercise reasonable caution in avoidance of devices which generate a strong electric or magnetic field. Close proximity to high levels of electromagnetic interference (EMI) may cause a neurostimulator to switch On or Off. The system also may unexpectedly cease to function due to battery depletion or other causes. For these reasons, the patient should be advised about any activities that would be potentially unsafe if their symptoms unexpectedly return. For additional information about devices which generate electromagnetic interference, call Medtronic at 1-800-707-0933. Patient Magnet – The magnet provided to the patient for device activation and deactivation may damage televisions, computer disks, computer monitors, credit cards, and other items affected by strong magnetic fields. Radio Frequency Sources – Analog and digital cellular phones, AM/FM radios, cordless phones, and conventional wired telephones may contain permanent magnets. To prevent undesired turning On or Off of the stimulation, these devices should be kept at least 4 inches away from the implanted neurostimulator. Therapeutic Magnets – Therapeutic magnets (for example, those found in bracelets, back braces, shoe inserts and mattress pads) can cause inadvertent on or off activations of the neurostimulator. Therefore, patients should be advised not to use them. 17 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Clinical Studies and Adverse Events Clinical Studies and Adverse Events The clinical use of the Kinetra Model 7428 Neurostimulator is supported by the Medtronic Parkinson’s disease clinical studies using the Itrel II Model 7424 Neurostimulator. For results of the Parkinson’s disease clinical trials and a complete list of adverse events reported during the Parkinson’s disease clinical trials, refer to the Activa Clinical Summary packaged with this product. Because safety and effectiveness of the Activa Parkinson’s Control therapy was established using bilateral Itrel II neurostimulators, clinical results and adverse event rates associated with a single dualchannel Kinetra neurostimulator may not be identical. Individualization of Treatment For information about individualization of treatment, refer to the Activa Clinical Summary packaged with this product. Resterilization The implantable components of the Activa System were sterilized with ethylene oxide prior to shipment. The package should be inspected for damage prior to use. If you are unsure of the components’ sterility for any reason, they can be resterilized at the hospital site. Note: If contamination is suspected because of a defective sterile package seal, the neurostimulator and accessories can be returned to Medtronic for replacement or they can be resterilized at the hospital. Replacements are otherwise subject to the terms of the Medtronic Limited Warranty (US Customers). Medtronic does not accept returned neurostimulators or accessories for resterilization and return them to customers. Because of variations in hospital sterilizers, precise instructions for sterilization or aeration cannot be given here. If further information is 18 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Resterilization necessary regarding the procedures to be used, contact the manufacturer of the sterilizer unit. Use biological indicators or other acceptable methods to validate the effectiveness of the hospital’s sterilizer unit. Medtronic cannot accept the responsibility for the hospital’s resterilization of any components. If, however, the hospital decides to resterilize, usual and customary sterilization methods should be used. # Cautions: ■ Do not resterilize and use the neurostimulator or accessories after exposure to body tissues or fluids. ■ Do not use radiation to resterilize any component. DO NOT AUTOCLAVE the neurostimulator. DO NOT CLEAN the neurostimulator in ULTRASONIC CLEANERS. Subject to the foregoing, the following may be considered: Ethylene oxide is an acceptable method for resterilization when the neurostimulator and accessories are repackaged in an ethylene oxide-permeable package. The temperature during the process should not exceed 131° F (55° C). The maximum possible aeration must be allowed before implanting the neurostimulator and using the accessories. Resterilization of a neurostimulator does not change the Use By date established at the time of manufacture, because the date is based on battery life. Steam autoclaving may be used for the hex wrenches only. To autoclave the hex wrenches, a standard cycle of 30 minutes at 250° F (121° C) and 15 psig is recommended. For “flash” autoclave, a standard cycle of 5 minutes at 270° F (132° C) and 27 psig is recommended. 19 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Directions for Use Neurostimulator Implantation or Replacement This section outlines the basic steps of the suggested procedure for implanting or replacing the neurostimulator. Refer to the appropriate extension implant manual for specific information related to the extension implant procedure. Once the verification of the efficacy of deep brain stimulation for your patient has been determined during the test stimulation procedure, the extension and neurostimulator may be implanted. To implant the neurostimulator: 1. Remove the percutaneous extension(s), if used, in accordance with the procedure outlined in the appropriate extension manual. 2. Create a subcutaneous pocket for the neurostimulator using blunt dissection in the subclavicular region. Notes: ■ If MRI is planned, avoid, if possible, implanting the neurostimulator in the abdomen. This requires the use of a longer length lead/extension system that can increase heating from MRI induced RF currents, especially at the lead electrodes. See “Appendix B: MRI and Activa Therapy” on page 74 for comprehensive safety information and instructions. ■ The neurostimulator should be located no more than 1.5 inches (4.0 cm) beneath the surface of the skin in subcutaneous tissue to allow proper programming. The device must be placed parallel to the skin surface. The etched identification side of the neurostimulator must face outward, away from muscle. When placing two neurostimulators, ensure a minimum of 8 inches (20 cm) separates the two to prevent cross-programming. 20 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use ■ In placing the neurostimulator, take into account the possibility of future cardiac needs (e.g., pacemakers, defibrillators, etc.). Implanting the neurostimulator on the right side allows for possible future placement of cardiac devices on the left side. Place the neurostimulator away from bony # Caution: structures with the etched identification side facing outward, away from muscle tissue to minimize pain at the neurostimulator site, and to minimize the possibility of skeletal muscle stimulation, which may be perceived by patients as twitching or burning. 3. Place the neurostimulator in the pocket to assure a proper fit and then remove it. Tunneling to the Neurostimulator Site For instructions on tunneling to the neurostimulator site refer to the appropriate extension manual. Making the Lead-Extension Connection For instructions on making the lead-extension connection refer to the appropriate extension manual. Making the Extension-Neurostimulator Connection To make the connection between the extension and the neurostimulator: 1. Check the neurostimulator connector block and determine if any setscrews obstruct the socket. If necessary, partially back out the setscrews. a. To back out a setscrew, insert the hex wrench through the pre-pierced hole in the rubber grommet and turn the 21 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use setscrew counterclockwise only until the socket is unobstructed (Figure 2). Note: With the Kinetra Model 7428 Neurostimulator, four setscrews are located on top of the connector module, two for each extension. Two setscrews are oriented at a 90° angle and two are oriented at a 45° angle. Limit counterclockwise rotations of the setscrews. # Caution: Rotate enough to provide an unobstructed pathway for extension connector pins. Too many rotations may disengage the setscrew from the neurostimulator connector block. 45° Angle 90° Angle Figure 2. Insert hex wrench in rubber grommet and turn setscrew counterclockwise to back out setscrew. b. Wipe off any body fluids from the extension connector pins and connector block. c. Check that the encapsulated diagram on the extension matches the diagram on the neurostimulator. d. Insert the Extension 1 connector pins fully into Socket I. Socket I corresponds to electrodes 0-3 on Lead 1. 22 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use e. Insert the Extension 2 connector pins fully into Socket II (Figure 3). Socket II corresponds to electrodes 4-7 on Lead 2. Note: If inserting the extension pins is still difficult, use sterile water as a lubricant. Socket I (Electrodes 0-3) Socket II (Electrodes 4-7) Extension 1 Extension 2 Figure 3. Insert extension connector pins into neurostimulator sockets. 2. Once the extension connector pins are fully inserted in the neurostimulator sockets, do the following for each of the four setscrews: a. Insert the hex wrench through the rubber grommet to engage the setscrew. b. Tighten the setscrew by turning the hex wrench clockwise until resistance is felt (Figure 4). c. Continue tightening for a maximum of 1/4 turn. The setscrews must touch the extension connector pins for proper electrical connection. Note: When tightening the setscrews, the hex wrench must be oriented at the same angle as the setscrews (Figure 4). 23 220822001 Rev X 7428_EN.FM 12/15/03 4:05 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use # Cautions: To prevent undertightening the neurostimulator ■ setscrews, do not use the torque wrench from the extension kit. Undertightening may result in insufficient electrical contact within the connector block, which may cause intermittent stimulation. ■ Do not overtighten the setscrews or permanent damage to the setscrews and/or sockets could result. ■ Be sure the hex wrench is fully inserted to prevent damage to the setscrew. ■ Verify that each leaf of the sealing rubber grommet has closed after the wrench is withdrawn. If the grommet seal is not fully closed, the patient may experience shocking, burning, or irritation at the neurostimulator implant site. In addition, fluid leakage into the setscrew connector block may result in changes to stimulation. 45° Angle 90° Angle Figure 4. Insert hex wrench and tighten all four setscrews. Note: The sealing rings within the neurostimulator connector block are designed to form a seal with the extension connector pins. No sealant or sutures are required. 24 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use 3. Place the neurostimulator into the subcutaneous pocket (Figure 5). Position the neurostimulator so that no sharp bends occur along the extension or lead (Figure 6). Place the neurostimulator away from bony # Caution: structures and with the etched identification side facing outward, away from muscle tissue to minimize pain at the neurostimulator site, and to minimize possibility of skeletal muscle stimulation, which may be perceived by the patient as twitching or burning. Figure 5. Place neurostimulator into subcutaneous pocket. Do not loop or coil the extension on top of the # Caution: neurostimulator’s etched identification side. Wrap any excess extension wire around the perimeter of the neurostimulator (Figure 6). This avoids any increase in subcutaneous pocket depth, minimizes potential damage during replacement surgery, and minimizes potential kinking of the extension wire. 25 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Figure 6. Wrap excess wire around the perimeter of the neurostimulator. 4. Secure the neurostimulator in the subcutaneous pocket, using the suture holes in the connector block to secure it to the muscle fascia. (Figure 7). Suture Holes Figure 7. Suture hole locations on neurostimulator connector block. 5. Check the stimulation parameters. 6. Confirm that the desired program is stimulating the desired area (e.g., that Program 1 (Lead 1) stimulates the left side and Program 2 (Lead 2) stimulates the right side). 7. Close and dress the incision. 26 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use 8. Complete the patient registration form and mail it to Medtronic. If the neurostimulator case is ruptured or pierced w Warning: after implant due to outside forces, severe burns could result from exposure to battery chemicals. Note: If only one lead is implanted at this time, perform the following steps using the accessories from the Model 3550-09 Accessory Kit: ■ 1 Lead, 1 Extension—Insert the neurostimulator connector plug into the unused socket of the neurostimulator connector block and tighten the setscrews (Figure 8). Figure 8. Insert connector plug into unused neurostimulator socket. ■ 1 Lead, 2 Extensions—Slide the closed boot over the extension’s setscrew connector and secure with sutures (Figure 9). 27 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Figure 9. Slide closed boot over extension setscrew connector and suture. To replace the Kinetra Neurostimulator: 1. Open the neurostimulator implant site per normal surgical procedure, and carefully remove the neurostimulator from the subcutaneous pocket. Use care to avoid damaging the extension wire # Caution: which may be wrapped around the perimeter of the neurostimulator. 2. Clean the neurostimulator and extension connector with sterile water; wipe both dry with surgical sponges. 3. Insert the hex wrench included in the package through the prepierced hole in the rubber sealing grommet, and loosen the setscrews by turning counterclockwise (Figure 2). 4. Gently retract the extension pins from the neurostimulator connector. If the extension pins show any signs of pitting corrosion, the extension should be replaced. Clean and dry both the pins and extension connector body—they must be free of fluids or tissue. 5. Check the neurostimulator connector and determine if any setscrews obstruct the socket space. If necessary, back out the setscrews. 6. Insert the Extension 1 connector pins fully into Socket I. Socket I corresponds to electrodes 0-3 on Lead 1. 7. Insert the Extension 2 connector pins fully into Socket II (refer to Figure 3). Socket II corresponds to electrodes 4-7 on Lead 2. 28 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use 8. Tighten each setscrew clockwise until it touches the connector pin—continue tightening for a maximum of 1/4 turn only (Figure 4). When tightening the setscrews, the hex wrench must be oriented at the same angle as the setscrews (refer to Figure 4). After you remove the wrench, check that the sealing rubber grommet has closed. # Cautions: To prevent undertightening the neurostimulator ■ setscrews, do not use the torque wrench from the extension kit. Undertightening may result in insufficient electrical contact within the connector block, which may cause intermittent stimulation. ■ Do not overtighten the setscrews or permanent damage to the setscrews and/or sockets could result. ■ Be sure the hex wrench is fully inserted to prevent damage to the setscrew. ■ Verify that each leaf of the sealing rubber grommet has closed after the wrench is withdrawn. If the grommet seal is not fully closed, the patient may experience shocking, burning, or irritation at the neurostimulator implant site. In addition, fluid leakage into the setscrew connector block may result in changes to stimulation. 9. Place the new neurostimulator into the subcutaneous pocket, with the etched identification side facing outward, and secure. Note: The neurostimulator should be located no more than 1.5 inches (4.0 cm) beneath the surface of the skin in subcutaneous tissue to allow proper programming. The device must be placed parallel to the skin surface. The etched identification side of the neurostimulator must face outward, away from muscle. If another neurostimulator is already implanted or planned for the future, ensure at least 8 inches (20 cm) between the two. 29 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use # Cautions: ■ Place the neurostimulator away from bony structures and with the etched identification side facing outward, away from muscle tissue to minimize pain at the neurostimulator site, and to minimize possibility of skeletal muscle stimulation, which may be perceived by the patient as twitching or burning. ■ Do not loop or coil the extension on top of the neurostimulator’s etched identification side. Wrap any excess extension wire around the perimeter of the neurostimulator (Figure 6). This avoids any increase in subcutaneous pocket depth, minimizes potential damage during replacement surgery, and minimizes potential kinking of the extension wire. 10. Use the suture holes in the connector block to secure the neurostimulator in the subcutaneous pocket. Use normally available surgical needles and sutures. 11. Check the stimulation parameters. 12. Confirm that the desired program is stimulating the desired area (e.g., that Program 1 (Lead 1) stimulates the left side and Program 2 (Lead 2) stimulates the right side). 13. Close the neurostimulator pocket incision. 14. Fill out and mail the implant registration form to Medtronic. If the neurostimulator case is ruptured or pierced w Warning: after implant due to outside forces, severe burns could result from exposure to battery chemicals. 30 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Explant Disposition Explanted products must be returned to Medtronic for proper disposal. Please include an explanation of explant on the Returned Product Information Report that is packaged with the Self-addressed Mailer Kits provided by Medtronic. Return explanted products to: Medtronic Inc. Neurological Division Returned Product Analysis MS N600 P.O. Box 1250 Minneapolis, MN 55440-9087 The self-addressed mailer kits are available from your Medtronic Sales Representative. Environmental Problems Kinetra neurostimulators are designed to assure immunity from most common sources of electromagnetic interference (EMI). Because many different types of EMI sources exist, it is impossible to specify all interference sources here. However, the most common sources of EMI are discussed below. Hospital or Medical Environment Kinetra neurostimulators have been tested for electromagnetic compatibility (EMC) in electrical and magnetic fields that simulate common sources of EMI found in a hospital environment. Severe electromagnetic fields, such as those that exist near electrocautery equipment, can reprogram a neurostimulator, temporarily suppress the output of a neurostimulator, and cause damage to the implanted system components. Telemetry usually continues to function but may indicate that the neurostimulator output is On when, in fact, no stimulation is being delivered because the amplitude is set to 0.0 V. Kinetra 31 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use neurostimulators have a protective circuit to prevent damage to the circuitry, but a large burst of electromagnetic energy may temporarily affect the output and/or the ability to reprogram the device. Severe EMI (e.g., electrocautery, defibrillatory discharge, MRI) can also erase the neurostimulator serial number. Refer to the section Precautions: Medical Environment for information on the interaction between specific medical equipment and the Activa System. Home or Job Environment Kinetra neurostimulators should not be affected by normal operation of electrical equipment such as household appliances, electric machine shop tools, microwave ovens, RF transmitting systems, or microwave frequency transmitting systems. A strong magnetic field (electromagnet or permanent magnet) can switch the neurostimulator output from On to Off or Off to On1, but does not change the programmed parameters. In addition, theft detectors and airport/security screening devices can affect the neurostimulator output and patient stimulation. Advise your patients to use care when approaching theft detectors or airport/security screening devices. If they feel unwanted stimulation as they approach the device, suggest that they request assistance to bypass the device. 1 Unexpected On/Off switching of the Kinetra Model 7428 Neurostimulator may be avoided by disabling the magnet control circuit with the clinician programmer software. If the magnet control circuit is disabled, patients will require a Model 7436 Therapy Controller to turn their therapy On or Off. Refer to “Control Magnet” on page 44. 32 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Theft detectors found in retail stores, public w Warning: libraries, etc., and airport/security screening devices may cause the stimulation power source of an implantable neurostimulation system to switch On or Off. It is also possible that sensitive patients, or those with low stimulation thresholds, may experience a momentary increase in their perceived stimulation. For other indications, higher levels of stimulation have been described as uncomfortable (“jolting” or “shocking”) by some patients as they pass through these devices. Refer to “Patient Counseling Information” on page 36 for more information. Advise your patients to avoid or to exercise care when approaching the following: ■ Theft detectors ■ Airport/security screening devices ■ Large stereo speakers with magnets ■ Electric arc welding equipment ■ Electric steel furnaces ■ Electric induction heaters (used in industry to bend plastic) ■ Power lines ■ Electric substations and power generators If your patient suspects an electrical device or magnet is interfering with the neurostimulator, advise him/her to move away from it, or turn the device off. Then, the patient can use the control magnet or therapy controller to set the neurostimulator back to the desired On or Off state. When switched On, the neurostimulator will resume stimulation at the previously programmed level. 33 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Directions for Use Handling and Storage The neurostimulator can be damaged if dropped on a hard surface, that is, dropped from a height of 30 cm (12 in.) or more onto a surface like a concrete floor. If this happens, the unit should not be implanted. The neurostimulator should not be stored at temperatures above 131° F (55° C) or below 0° F (-18° C). Patient Registration Inside the shipping container for each Kinetra Neurostimulator is an implant registration form that creates a permanent record of your patient’s implant. It is important that you complete the form and promptly return the original to Medtronic, Inc. Three copies are provided for the patient’s medical records. Medtronic will transfer vital information to a wallet-sized, plasticcoated identification card and will mail it directly to the patient. A temporary identification card is packaged with the neurostimulator for the patient’s use until the permanent card arrives. In addition to the patient identification card, the information on the form registers the device warranties and creates a record of the implant in Medtronic’s implant data system. The information in this system ensures compliance with the Safe Medical Devices Act (USA). 34 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Physician Training Information Physician Training Information Prescribing physicians should have expertise in the medical treatment of patients with movement disorders. Implanting physicians should have expertise with functional stereotactic neurosurgical treatment of movement disorders. Such expertise should include knowledge of the anatomical and neurophysiological characteristics of the targeted nucleus, surgical and /or implantation techniques for the Activa System, operational and functional characteristics of the Activa System, and experience in the continued management of patients by stimulation parameter adjustment. Physicians may contact Medtronic before prescribing or implanting an Activa System for the first time and request a referral to a physician experienced in the use of Activa Therapy. All Activa System programming should be by or under the supervision of a physician or other experienced medical personnel familiar with the use of the programming software and equipment. Physicians should be thoroughly familiar with Activa System supporting material, including: ■ All product labeling, and ■ Education and training materials. 35 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Patient Counseling Information Patient Counseling Information Before surgery, the patient and family should be advised of the known risks of the surgical procedure and the therapy, as discussed in other sections of this manual, as well as the potential benefits. After the Activa System is implanted, the patient should also be advised to read the patient manual included in the neurostimulator package. Theft Detectors and Screening Devices Patients should be advised to use care when approaching security arches or gates (such as those found in airports, libraries, and some department stores) because these devices can turn on or turn off their neurostimulator. If an airport security wand is used, they should ask the security personnel to avoid placing the wand over the neurostimulator. When approaching these devices, patients should do the following: 1. If security personnel are present, show them the neurostimulator identification card and request a hand search. 2. If patients must pass through the security device, they should approach the center of the device and walk normally (Figure 10). a. If two security gates are present, they should walk through the middle, keeping as far away as possible from each gate. b. If one gate is present, they should walk as far away as possible from it. Note: Some theft detectors may not be visible. 3. Proceed through the security arch or gate. Do not touch, lean on or linger near the security arch or gate. 36 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Patient Counseling Information Double Security Gate Single Security Gate (Stay as far away as possible from gate) Figure 10. Approaching security gates. 4. If patients suspect that their neurostimulator was turned off, they should make sure someone is able to turn on the system again. (This person could be the patient, if his or her medical condition allows it. It could also be a family member or clinician who has been taught how to use the system.) Component Manipulation by Patient Advise your patient to avoid manipulating the implanted system components (e.g., the neurostimulator, the burr hole site). This can result in component damage. 37 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Kinetra Patient Eligibility Kinetra Patient Eligibility Prior to neurostimulator implant, ensure that the Kinetra Neurostimulation System is appropriate for your patient. Rate Control If independent rate control is desired to provide adequate symptom control for your patient, be aware that rate parameter values are not independently programmable with the Kinetra Model 7428 neurostimulator. Consider implanting two Soletra Model 7426 neurostimulators if independent rate values are desired. Note: In Medtronic’s clinical studies of the Itrel II Model 7424 neurostimulator for advanced Parkinson’s disease, at least 58% of all subjects had identical rates bilaterally at all follow-up visits. Screening for Patient Eligibility Verify that the screening parameters do not exceed the maximum amplitude shown in Table 1 on page 39. If test stimulation is unsuccessful or if parameter settings to achieve therapeutic benefit are within the charge density warning area (refer to Figure 13 on page 52), the system should not be implanted. 38 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Kinetra Patient Eligibility Table 1. Maximum Amplitude (Volts) Available for Specific Rate/Pulse Width Combinations.a,b Pulse Width (Microseconds) Rate (Hz) a b 60 90 120 150 180 210 130 9.5 V 9.5 V 9.5 V 9.0 V 8.0 V 7.5 V 140 9.5 V 9.5 V 9.0 V 8.5 V 8.0 V 7.5 V 150 9.5 V 9.5 V 9.0 V 8.0 V 7.5 V 7.0 V 160 9.5 V 9.5 V 8.5 V 8.0 V 7.0 V 6.5 V 170 9.5 V 9.5 V 8.5 V 7.5 V 6.5 V 6.5 V 185 9.5 V 9.0 V 8.0 V 7.0 V 6.5 V 6.0 V 200 9.5 V 8.5 V 7.5 V 7.0 V 6.0 V 5.5 V 220 9.0 V 8.0 V 7.5 V 6.5 V 5.5 V 5.0 V 250 9.0 V 7.5 V 7.5 V 5.5 V 5.0 V 4.5 V This table is based on data collected with a 1000 ohm resistive load. If the screening rate is between table settings, use the next higher rate. The shaded area has upper limits that exceed the charge density warning threshold. See Figure 13 on page 52. 39 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Detailed Device Description General Description The Kinetra Neurostimulator has a wide range of noninvasively programmable parameters and stimulation modes. The neurostimulator provides current parameter information, via telemetry, when used with the clinician programmer. The following sections outline the major neurostimulator features. Programs The stimulation pulses delivered to each lead are determined by a parameter called a program. A program is a specific combination of amplitude, rate, and pulse width parameters acting on a specific electrode set. The Kinetra Model 7428 Neurostimulator has two available programs (P1 and P2). Program 1 corresponds to Lead 1 (electrodes 0-3 and the case) and Program 2 corresponds to Lead 2 (electrodes 4-7 and the case). Rate is not independently programmable; one programmed setting determines the rate for both programs. Dual-Program Stimulation Dual-program pulses are delivered alternately rather than simultaneously. Program 1 delivers an output pulse at its programmed amplitude and pulse width parameters, followed by the Program 2 output pulse at its programmed amplitude and pulse width parameters. This sequence is repeated, with single output pulses alternately delivered. Figure 11 illustrates dual-program operation. 40 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Different amplitude and pulse width on both programs1 Same amplitude and pulse width on both programs1 1 Lead 1 (P1) Lead 2 (P2) Lead 1 (P1) Lead 2 (P2) Rate is always the same for both programs Figure 11. Examples of dual-program stimulation. Programmable Functions The Kinetra Neurostimulator is programmed with either the Model 7432 Clinician Programmer and the MemoryMod Model 7459 Software Cartridge or the Model 8840 Clinician Programmer and the Model 8870 Application Card. The clinician programmer is used to program the stimulation parameters for both programs by telemetry. It controls various parameters and stimulation modes (Table 2). The clinician programmer displays instruction “prompts” and shows parameter data. A “hard-copy” printout can also be produced during a programming sequence. Some features include Day Cycling, SoftStart/Stop, and Control Magnet Enable/Disable. Patient use information is also available. Neurostimulator internal counters automatically monitor items such as total stimulation time and total number of activations. The Access Model 7436 Therapy Controller allows the patient to turn the neurostimulator on and off and check the neurostimulator battery status (device shipped with these features active). In addition, the Kinetra Neurostimulator can be programmed with upper and lower limits for amplitude, pulse width, and rate. The Kinetra 41 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Neurostimulator is shipped with these optional limits set to ±0. When these optional limits are enabled by the physician, patients can adjust their stimulation within the prescribed limits using the therapy controller. These optional limits may not be appropriate for all patients. Physician discretion will need to be exercised to determine whether an individual patient or caregiver is capable of managing parameter control. For a complete description of programmable functions, refer to the manuals supplied with the software and therapy controller. Programmers made by other manufacturers are not compatible with the Kinetra Model 7428 Neurostimulator. Table 2. Kinetra Model 7428 Controlling Devices and Functions. Controlling Device Function 7432 Programmer with 7459 Software 8840 Programmer with 8870 Software • Switches Neurostimulator Output On/Off and provides neurostimulator battery status • Programs Stimulation Parameters and limits for Programs 1 and 2 • Programs Stimulation Modes • Collects Measurements and Diagnostic Data • Programs Special Features 7436 Therapy Controller • Switches Neurostimulator Output On/Off • Gives Neurostimulator On/Off Status • Adjusts Stimulation Parameters within Physician Prescribed Limits for both Programs • Provides Neurostimulator Battery Status 7452 Control Magnet • Switches Output On/Off if the magnet function has been enabled with the clinician programmer 42 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description For a description of programmer operations and programming functions, refer to the appropriate hardware technical manual or software programming guide. Telemetry Data The Kinetra neurostimulator is capable of providing telemetry data transmissions when properly reviewed by the clinician programmer. Upon interrogation, Kinetra neurostimulators will transmit the following via a radiofrequency (RF) link to the clinician programmer for display or printing: ■ Model and serial number identification ■ Programmed parameters and values ■ Neurostimulator battery status ■ Number of patient activations (since last reset) ■ Total stimulation time (since last reset) ■ Elapsed time (since last reset) ■ Verification of program changes After a program entry, the programmer compares neurostimulator parameters, via telemetry, with the entries made during programming. The neurostimulator parameter or mode is changed to match the entry and the new value or mode is registered on the display. Do not send a patient home with any invalid values # Caution: for programmable parameters displayed on the programmer screen. They must be reprogrammed to valid parameter values. Note that severe EMI (e.g., electrocautery, defibrillatory discharges, MRI) can erase the neurostimulator serial number. Only the clinician programmer can receive and display telemetry data from the neurostimulator. 43 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Control Magnet The control magnet enables your patient to switch the neurostimulator output On or Off. The patient briefly applies the Medtronic Model 7452 Control Magnet over the implanted neurostimulator and then removes it to turn the neurostimulator On or Off. Application of the magnet for 2 seconds followed by removal causes the output circuit to turn On or Off. The magnet On/Off control circuit is enabled when the flat edge of the magnet is applied over the neurostimulator implant site for 2 seconds (Figure 12). The actual switching occurs when the magnet is withdrawn. The magnet On/Off control circuit does not affect programmed parameters; when the output is switched On using the magnet, the output resumes its previously programmed waveform and stimulation mode. Magnet Figure 12. Magnet properly positioned over neurostimulator. The magnet control circuit can be disabled with the clinician programmer software. Patients who are exposed to magnets or strong electromagnetic fields may experience unexpected On/Off switching of their neurostimulators. If On/Off switching occurs, you can disable the magnet control circuitry with a command to the neurostimulator from the clinician programmer. The magnet control circuit can later be enabled with another command from the clinician programmer, if desired. Detailed instructions on this disable feature 44 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description are contained in the programming guide provided with the clinician programmer. If the On or Off control by the magnet-actuated reed # Caution: switch is disabled, the patient must have a therapy controller to turn the neurostimulator on or off. Neurostimulator Counters Patient Activations – Each time the neurostimulator is turned On, the activation is counted on the Patient Activation Counter. This counter will count up to 32,767 patient activations, and it can be read by telemetry and reset by a special programming command. Total Stimulation Time – The total stimulation time is the amount of time the neurostimulator is On (with amplitude > 0) since the counter was last reset. It is a cumulative total with a counter capacity of 8,738 hours, or approximately 1 year. If cycling is programmed, Off cycle time is included. Elapsed Time – The elapsed time is the amount of total time since the counters were last reset. The capacity of this counter is 8,192 hours, or approximately one year. Counter Reset – All counters can be reset with the clinician programmer. Postoperative Patient Management The treating clinician(s) should be experienced in all aspects of the medical management of patients with Parkinson’s disease. Clinicians using Activa Therapy for the first time are encouraged to contact a Medtronic representative for information on the postoperative management of Activa patients. When programming stimulation parameters, give consideration to the following programming recommendations regarding initial stimulation parameters. 45 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Programming Initial Stimulation Parameters for Activa Parkinson’s Control Therapy – The following procedure provides instructions on programming post-operative stimulation parameters for Activa Parkinson’s Control Therapy, and is one approach for the physician’s consideration. Notes: ■ High amplitude/pulse width combinations can result in excessive charge density. Refer to “Programming Stimulation Parameters” on page 49 for more information. ■ With the Kinetra Model 7428 Neurostimulator operating in a dual-program configuration, select stimulation parameters for Program 1 (Lead 1) and Program 2 (Lead 2). ■ If independent rate control is desired to provide adequate symptom control for your patient, be aware that rate parameter values are not independently programmable with the Kinetra Model 7428 neurostimulator. 1. Allow sufficient time for the patient to recover from surgery. Schedule the initial programming visit so that the patient is in an “off” period, when the Parkinson’s disease symptoms are predominant. 2. Set the neurostimulator to the initial settings provided in Table 3. 3. To evaluate the potential effectiveness of all electrodes, select a predominant Parkinson’s disease symptom, such as rigidity or tremor, that responds to changes in stimulation. 46 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Table 3. Programming Settings for Activa Parkinson’s Control Therapy Parameter Typical Initial Setting Range/ Options Typical Final Setting Amplitude 0.0 V Normal: 0-10.5 V Fine: 0-6.35 V 2.5-3.5 V Pulse Width 60-120 µsec 60-450 µsec 60-120 µsec Ratea 130-160 pps 3-250 pps 130-185 pps Unipolar Unipolar or Bipolar Variesb Continuous Cycling or Continuous Continuous Electrode Polarity (Refer to “Electrode Programming Configurations” on page 53) Mode a b The same value for rate is programmed for both Program 1 and Program 2. In the Medtronic-sponsored clinical investigation, most STN patients used unipolar stimulation, whereas similar proportions of GPi patients used unipolar and bipolar stimulation. 47 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description 4. To expedite electrode selection, program the neurostimulation system to a unipolar electrode configuration where the neurostimulator case is the positive electrode, electrode 0 is the negative electrode for Program 1, and electrode 4 is the negative electrode for Program 2. Note: It may be desirable to ultimately program the neurostimulation system to a bipolar electrode configuration, where both the positive and negative electrical poles are the lead electrodes. This can reduce the potential for electromagnetic interference-related side effects, and may optimize battery life. 5. Gradually increase amplitude by 0.1 - 0.5 V incrementally until a predominant Parkinson’s disease symptom (rigidity, tremor) is suppressed. Wait a few minutes to assess the effect of stimulation. 6. If there is uncomfortable stimulation or inadequate symptom suppression, reduce the amplitude to 0 V and select another electrode as the negative electrode. Repeat step 5. Select the electrode that provides the best control of symptoms with the fewest side effects. 7. After the most desirable negative electrode is selected, gradually increase the amplitude until side effects occur. The therapeutic window between symptom suppression and occurrence of side effects should be sufficiently wide to allow for future amplitude adjustments. 8. Evaluate the patient in an “on” period, when Parkinson’s disease symptoms are controlled after a usual dose of antiparkinsonian medication. Assess the effect of stimulation on suppressing or worsening of dyskinesias. 9. After Amplitude settings are determined, adjust Pulse Width and Rate to improve therapeutic benefit and minimize side effects. 48 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Notes: ■ Symptom suppression is desirable at the lowest possible amplitude, rate, and pulse width in order to improve battery longevity and minimize charge density. ■ The same value for rate is programmed for both Program 1 and Program 2. 10. Document final parameter settings for future reference. Programming Stimulation Parameters When programming stimulation parameters, give consideration to the following recommendations regarding high output interlocks and charge density. High Output Interlocks – Certain combinations of high amplitude, pulse width, and rate stimulation settings are not allowed by the clinician programmer. If you attempt to program a parameter value (or limit) that will cause the settings to exceed the high output interlock limit, the desired parameter value can only be achieved by reducing one of the other parameter values. Refer to Table 4 for information on limited amplitude at high programmed rate and pulse width combinations. Note: If the upper limit for amplitude, pulse width, or rate is programmed to a higher value than the programmed value, the programmer will use this value when determining a high output interlock. 49 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Table 4. Maximum Programmable Amplitude at High Rate/Pulse Width Combinations. Programmed Limited Amplitude at High Rates (Hz) PW (µsec) 130 150 175 200 220 250 90 10.5 V 10.5 V 10.4 V 9.9 V 9.5 V 9.1 V 120 10.4 V 10.0 V 9.5 V 9.0 V 8.6 V 8.1 V 180 9.2 V 8.7 V 8.1 V 7.6 V 7.0 V 6.4 V 240 8.3 V 7.7 V 7.1 V 6.6 V 6.0 V 5.5 V 300 7.3 V 6.8 V 6.2 V 5.7 V 5.4 V 5.0 V 360 6.8 V 6.2 V 5.6 V 5.0 V 4.7 V 4.3 V 420 6.4 V 5.9 V 5.3 V 4.8 V 4.5 V 4.1 V 450 6.0 V 5.5 V 4.8 V 4.2 V 3.8 V 3.4 V Charge Densities – A survey of literature regarding electrical stimulation of neural tissue suggests that damage may occur above 30 microcoulombs/cm2/phase. The Activa System is capable of producing charge densities in excess of 30 microcoulombs/cm2/ phase (Figure 13). The device’s maximum amplitude is 10.5 V, and maximum pulse width is 450 microseconds. The curved lines in Figure 13 represent a charge density of 30 microcoulombs/cm2/phase at various impedance measurements, calculated for the electrode surface area of the DBS Model 3387/3389 Lead. Mean resistance found in the clinical studies were as follows. ■ Parkinson’s disease clinical studies (all targets): 1294 ohms (range: 415-1999 ohms). ■ Parkinson’s disease clinical studies (GPi): 1161 ohms (range: 415-1967 ohms). 50 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description ■ Parkinson’s disease clinical studies (STN): 1177 ohms (range: 628-1926 ohms). Charge density is determined by plotting a point corresponding to the pulse width setting (x-axis), and the amplitude setting (y-axis). If this point is below the appropriate resistance curve, then the charge density is below 30 microcoulombs/cm2/phase. Points above the curve indicate a charge density above 30 microcoulombs/cm2/ phase. The shaded area of Figure 13 indicates a charge density above 30 microcoulombs/cm2/phase at the conservative impedance estimate of 500 ohms. If stimulation parameters are selected that fall into the shaded area of the graph, the following programmer warning appears: WARNING: CHARGE DENSITY MAY BE HIGH ENOUGH TO CAUSE TISSUE DAMAGE. Programming may continue at the desired values (refer to the appropriate software application manual for further information). Figure 13 includes two examples of charge density calculated for the Activa System. In Example A, the Kinetra Model 7428 Neurostimulator is set to typical parameter settings for symptom suppression: amplitude = 3.0 V and pulse width = 90 µsec. The charge density for Example A is below the shaded warning zone, thus indicating a charge density below 30 microcoulombs/cm2/phase at the most conservative impedance of 500 ohms. In Example B, neurostimulator stimulation parameters are set to: amplitude = 6.1 V and pulse width = 210 µsec. The charge density at these settings is in the shaded area indicating it may be high enough to cause tissue damage at an impedance of 500 ohms. However, as shown in Figure 13, if the impedance in this case is at the clinical mean from the Parkinson’s disease clinical study, the charge density would be below 30 microcoulombs/cm2/phase. 51 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Amplitude (Volts) DBS Amplitude and Pulse Width Limits Computed for resistances ranging from 500 to 2,000 ohms DBS Lead Surface Area = 0.06 cm2 Charge Density Threshold = 30 Microcoulombs/cm2/phase Pulse Width (Microseconds) Figure 13. Charge density with Parkinson’s disease clinical mean resistance. 52 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Electrode Programming Configurations The Kinetra Neurostimulation System offers two types of configurations: unipolar (neurostimulator case positive, lead electrode(s) negative) and bipolar (neurostimulator case off, one or more lead electrodes positive and one or more lead electrodes negative). In addition, by selecting and activating different combinations of electrodes available for the neurostimulation system, the stimulation can be tailored to individual patient therapy requirements. Some of the advantages and disadvantages of the configurations are discussed below. When selecting the configuration, check the impact on battery life. For more information on battery longevity, refer to “Appendix A: Battery Longevity Reference Information” on page 64. For more information on the leads or the extensions, refer to the technical manual packaged with the product. Use only leads that are compatible with the output w Warning: capabilities of the neurostimulator. Refer to the system components sheet. Bipolar Configurations – In a bipolar configuration, at least one lead electrode is positive and at least one lead electrode is negative, with the neurostimulator case Off. Using a bipolar configuration with one negative lead electrode and one positive electrode may maximize battery life. 53 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Unipolar Configurations – In a unipolar configuration, one or more lead electrodes are negative and the neurostimulator case is positive. Check the effect on battery life. Refer to “Appendix A: Battery Longevity Reference Information” on page 64. Note: Activating more than the minimum number of electrodes in either unipolar or bipolar configurations spreads the stimulation over a greater area, but may reduce the battery life. Activate additional electrodes only after other electrode combinations have been tried. However, check the effect on battery life. For more information on battery longevity, refer to “Appendix A: Battery Longevity Reference Information” on page 64. 54 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Front Back Figure 14. Electrode Configuration. 55 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Test Stimulation An intraoperative test stimulation phase during the lead implant procedure verifies a correct lead placement that results in symptom suppression with minimal side effects. Perform test stimulation intraoperatively. If there is no symptom suppression, do not implant the Activa System. Instructions for the test stimulation are included in the DBS Lead Implant Manual and the Model 3625 Test Stimulator Operator Manual. Specifications and Features The Kinetra Neurostimulator is powered by a hermetically sealed, silver vanadium oxide cell and uses integrated circuits. To protect the neurostimulator components from intrusion of body fluids, the electronics and power source are hermetically sealed within an ovalshaped titanium shield. Refer to Table 5 for a list of the parameter operating ranges, to Table 6 for parameter settings at shipping, and to Table 7 for the physical characteristics of the neurostimulator. The Kinetra Model 7428 Neurostimulator case has an external insulating coating to help minimize possible skeletal muscle stimulation at the neurostimulator implant site. An uninsulated area on one side of the neurostimulator (etched identification side) can serve as the positive electrode when using a unipolar configuration. The uninsulated side should be positioned outward, away from muscle tissue, toward the exterior of the body. Kinetra neurostimulators have a self-sealing connector assembly with a corrosion-resistant titanium-alloy body and titanium setscrews. This connector assembly can accommodate two extensions to form a dual-program system. Securing the extension requires the use of the hex wrench that is packaged with the neurostimulator. Other features of Kinetra neurostimulators include: two suture holes to enable you to secure the neurostimulator within the subcutaneous pocket; Power On Reset (POR); and a radiopaque identification code. 56 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Table 5. Kinetra Model 7428 Neurostimulator Programmable Parameter Values. Programmable Parameters Valuesa Pulse Amplitude b and Limits for Programs 1 and 2 Normal resolution: 0 to 10.5 V (0.1 V steps) Fine Resolution: 0 to 6.35 V (0.05 V steps) Rate and Limitsb,c 66 values from 3 to 250 Pulse Width and Limits for Programs 1 and 2b 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360, 390, 420, 450 µsec Cycle On Time 0.1 second to 24 hours Cycle Off Time 0.1 second to 24 hours Cycle On Time w/SoftStart 2 seconds to 24 hours Cycle Off Time w/SoftStart 2 seconds to 24 hours SoftStart/Stop 1, 2, 4, or 8 seconds Electrode Polarity for Program 1 0, 1, 2, 3, Electrodes: Off, Neg or Pos Case: Off or Pos Electrode Polarity for Program 2 4, 5, 6, 7, Electrodes: Off, Neg or Pos Case: Off or Pos Day Cycling ON Time 30 minutes to 24 hoursd Day Cycling OFF Time 30 minutes to 24 hoursd 57 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Table 5. Kinetra Model 7428 Neurostimulator Programmable Parameter Values. (continued) a b c d Programmable Parameters Valuesa Magnet ON/OFF Control Circuit Enabled or Disabled Note: All values are approximate. Note: Certain combinations of amplitude, pulse width, and rate are not allowed. Refer to “High Output Interlocks” on page 49. The same values for rate and rate limits are programmed for both Program 1 and Program 2. The sum of the ON and OFF times must equal 24 hours. Table 6. Kinetra Model 7428 Neurostimulator Shipping Settings. Description Value Amplitude for Programs 1 and 2 (Normal Resolution) Upper Limit Lower Limit 0 volts Rate for Programs 1 and 2 Upper Limit Lower Limit 130 pps +0 pps tracking -0 pps tracking Pulse Width for Programs 1 and 2 Upper Limit Lower Limit 90 µsec +0 µsec tracking -0 µsec tracking Output On/Off Switch Offa Mode Continuous Dual-Program +0 volts tracking -0 volts tracking SoftStart/Stop 4 seconds Magnet Control Circuit Enabled 58 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Table 6. Kinetra Model 7428 Neurostimulator Shipping Settings. (continued) a Description Value Electrode Polarity for Program 1 0 = Negative 1 = Off 2 = Off 3 = Positive Case = Off Electrode Polarity for Program 2 4 = Negative 5 = Off 6 = Off 7 = Positive Case = Off Note: Exposure to a strong source of electromagnetic interference (EMI) can cause the output switch to toggle to the On position. However, since the Amplitude setting is 0.0 V, there is no neurostimulator output. Table 7. Kinetra Model 7428 Neurostimulator Physical Description Description a b Valuea Height 2.4 in. (61 mm) Length 3.0 in. (76 mm) Thickness Case Connector 0.527 in. (13.4 mm) 0.590 in. (15.0 mm) Weight 2.9 oz (83 g) Volume 3.1 in3 (51 cm3) External Shield Titaniumb Storage Temperature -18° C to +55° C 0° F to +131° F All values are approximate. Note: The Kinetra Model 7428 Neurostimulator has an insulating coating to prevent undesirable muscle stimulation. The uninsulated side with the etched identification should be positioned outward, away from the muscle. 59 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Kinetra Neurostimulator Battery Longevity “Appendix A: Battery Longevity Reference Information” on page 64 in this manual can be used to help you estimate battery longevity for the Kinetra Neurostimulator at various parameter settings. The fewer the number of stimulation hours used daily, the longer the total longevity. The battery information provided in the appendix is theoretical. In actual use, parameters, usage time, and other factors such as impedance, may vary. Therefore, the tables and formulas cannot predict precise longevity for any given patient. However, once battery life is estimated, it is possible to set realistic expectations of battery life and achieve optimal battery life from the Kinetra Neurostimulator. Note: Battery life estimates are for a new implant and therefore should be made at the time of implant. Battery Status Indicators The clinician programmer enables you to monitor your patient’s neurostimulator battery status. The programmer provides both voltage and current measurements. For example, as the neurostimulator battery depletes, the telemetry readout will show LOW on the programmer’s display. If you use the printer, it will print LOW. As the battery voltage decreases further, the clinician programmer shows the battery status as EOL (End of Life) on the display, or prints EOL. After the neurostimulator battery has been depleted, telemetry is no longer possible. Refer to the table below for a summary of battery status messages and their meaning. 60 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description a Battery Status Indicators Battery Voltage Level OK Battery voltage is OK Low Battery voltage is approaching EOL (5-15% remaining capacity)a EOL (End-of-Life) Battery voltage is near depletion (<5% remaining capacity)a Schedule replacement surgery immediately. In addition to the neurostimulator battery status, the programmer can measure the battery voltage (volts), stimulation current (µamps), and battery capacity. It is recommended that stimulation current and impedance measurements be taken after every programming session with your patient. This information can be valuable at a later time if a malfunction develops. The measurements can be used to troubleshoot and isolate the problem. For example, measurements that show a significant reduction in stimulation current (or increase in impedance) can indicate a fractured lead conductor, a loose setscrew, and so forth. Conversely, a significant increase in stimulation current (or decrease in impedance) can indicate shorted conductors, a break in lead insulation, and so forth. In either case, it is very useful to know what the settings were when the system was operating properly. The battery capacity measurement calculates the voltage of the neurostimulator battery and the percentage of battery capacity consumed. Note: The neurostimulator must be Off to perform this measurement. 61 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Detailed Device Description Battery Depletion As the neurostimulator battery nears total depletion the output will gradually decrease and then vanish completely when the neurostimulator automatically shuts itself down. Patients may experience a decrease in symptom # Caution: suppression as the battery nears total depletion. Patients should be instructed to contact their clinician. Notes: ■ When the neurostimulator battery reaches Low status, the neurostimulator battery light on the therapy controller blinks when the patient interrogates the device. Patients should be instructed to contact their physician. ■ The clinician programmer calculates battery capacity remaining, so the physician can schedule neurostimulator replacement based on the patient settings and remaining battery capacity1. Power On Reset As a safety feature, each time there is a temporary interruption in battery output, the neurostimulator will automatically reset to zero amplitude and output Off, the electrodes and case will reset to Off, and the serial number will be lost. This could be caused, for example, by use of an electrocautery tip near the neurostimulator or by defibrillation. To restore stimulation, turn the neurostimulator On and program the neurostimulator to the previously programmed parameter values. 1 If the remaining battery capacity is 15% or less, schedule replacement surgery immediately. 62 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a How Supplied X-Ray Identification X-ray identification permits the determination of manufacturer and neurostimulator model number. With standard x-ray procedures, the code inside the connector block appears as white characters. The Medtronic symbol identifies Medtronic as the manufacturer. For the Kinetra Model 7428 Neurostimulator, the designated letters are NFD (Figure 15). Neurostimulator Connector Block Figure 15. X-ray identification location. How Supplied The Kinetra Model 7428 Neurostimulator package contains the following: ■ One Model 7428 Neurostimulator ■ One Hex Wrench ■ Product Literature Note: The contents of the inner package are STERILE. The neurostimulator and accessories contained in the package are intended for Single Use Only. 63 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Appendix A: Battery Longevity Reference Information With the Kinetra neurostimulator, you can expect battery life to range from months to years, depending on the parameters you have selected for your patient and the patient’s use of the system. Appendix A provides reference information that will assist you in estimating Kinetra battery longevity prior to neurostimulator internalization and maximize battery life during use. It contains the procedure, tables and formulas needed to estimate battery longevity plus tips for maximizing battery life. These estimates are based on programmed parameters and correction factors for electrode selection and expected usage time. However, actual battery life will vary due to other factors such as impedance, changes in stimulation requirements over time, amount of stimulation use, and stimulation parameters selected within the programmed limits for amplitude, rate, and pulse width. Tips for Maximizing Battery Life The following tips will help optimize Kinetra battery life: ■ Use the minimum number of active electrodes necessary for effective stimulation. ■ Use bipolar stimulation. Keeping all other programmed settings constant, changing to bipolar stimulation provides longer battery life than unipolar stimulation. ■ Use the lowest effective settings and upper limits for amplitude, rate, and pulse width. Estimating Battery Life Prior to Neurostimulator Internalization Follow this procedure to estimate Kinetra battery life prior to neurostimulator internalization. Use the worksheet on page 68 to record settings and calculate longevity. 64 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information 1. Determine the expected Program 1 operating parameters for the neurostimulator, including Amplitude, Rate, Pulse Width, number of active electrodes, cycle ON/OFF times, and hours of stimulation per day. 2. Determine the Program 1 Energy Use (EU) from Table 8 (page 71) using the expected values for amplitude, rate, and pulse width. Notes: ■ Use the table values that are closest to the expected values. Be aware that when values do not match, there will be a discrepancy between calculated longevity estimates and actual results. ■ Table 8 assumes neurostimulator usage of 24 hours per day. If neurostimulator usage is different from that, adjustments will be made in later calculations. 3. Determine the Program 1 Electrode Correction Factor (ECF) from Table 9 (page 72) for the number of active electrodes. Note: If selecting an electrode configuration for this program with only one positive and only one negative electrode (bipolar), you may skip step 3 because the Electrode Correction Factor is 1.0. 4. Multiply the Program 1 Energy Use by the Program 1 Electrode Correction Factor to obtain the Program 1 Factor (P1F). 5. Repeat steps 1 through 4 for Program 2 to obtain the Program 2 Factor (P2F). 6. Add the Program 1 Factor and the Program 2 Factor to obtain the Dual-Program Factor (DPF). 65 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information 7. Determine the Usage Correction Factor (UCF) from the following formula (the value will be between 0 and 1): Usage Correction Factor = Usage Ratio x Cycling Ratio [Usage Ratio = hours of stimulation (per day) ÷ 24 hours] [Cycling Ratio = cycle On ÷ (cycle On + cycle Off)] Notes: ■ If Cycling is not programmed, the formula becomes: Usage Correction Factor = Usage Ratio ■ If using Continuous mode with 24 hours of stimulation, you may skip step 7 because the Usage Correction Factor is 1.0. 8. Multiply the results of steps 6 and 7 to obtain the adjusted Energy Use value: DPF x UCF = adjusted Energy Use 9. Finally, take the adjusted Energy Use value and determine the estimated battery longevity in years from Table 10 (page 73). Example Assume the patient’s neurostimulator will be programmed to these settings: Amplitude: Program 1 = 2.7 V; Program 2 = 3.0 V Rate (for Programs 1 and 2) = 185 Hz Pulse Width: Program 1 = 60 µsec; Program 2 = 120 µsec Electrodes: Program 1 bipolar = 1 +, 2 –, remaining Off; Program 2 bipolar = 5 +, 6 –, 7 – and 4 Off Continuous mode Hours of Stimulation = 16 hours The Energy Use from Table 8 (page 71) would be 59 for Program 1 and 114 for Program 2. The Electrode Correction Factor from Table 9 (page 72) would be 1.0 for Program 1 and 1.3 for Program 2. 66 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Thus, the Program 1 Factor would be 59 x 1.0 = 59, and the Program 2 Factor would be 114 x 1.3 = 148.2, making the Dual-Program Factor 59 + 148.2 = 207.2. The Usage Correction Factor would be: Usage Ratio = 16 ÷ 24 = 0.66 Usage Correction Factor = Usage Ratio = 0.66 The adjusted Energy Use would be: 207.2 x 0.66 = 136.8 And the estimated battery longevity from Table 10 (page 73) would be 5 years. To show how small changes in parameter settings can have a big impact on battery longevity, consider this alternate example: All settings remain the same except the electrode configuration for both programs is changed to unipolar (case +) with 2 active electrodes. The Electrode Correction Factor for both programs would be 2.8. This would result in an adjusted Energy Use of 319.7 instead of 136.8, and a longevity estimate of 2.3 years instead of 5 years. 67 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Battery Longevity Worksheet Program 1 Energy Use (P1 EU) Amp ______ V Rate ______ Hz PW ______ µsec The Program 1 Energy Use (EU) from Table 8 on page 71 is: ______ Program 1 Electrode Correction Factor (P1 ECF) If the electrode configuration for Program 1 is one positive and one negative electrode, skip this step. Otherwise, the Program 1 Electrode Correction Factor (ECF) from Table 9 on page 72 is: ______ Program 1 Factor (P1F) Compute the Program 1 Factor: (P1 EU) _____ x (P1 ECF) _____ = _____ (P1F) Program 2 Energy Use (P2 EU) Amp ______ V Rate ______ Hz PW ______ µsec The Program 2 Energy Use (EU) from Table 8 on page 71 is: ______ 68 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Program 2 Electrode Correction Factor (P2 ECF) If the electrode configuration for Program 2 is one positive and one negative electrode, skip this step. Otherwise, the Program 2 Electrode Correction Factor (ECF) from Table 9 on page 72 is: ______ Program 2 Factor (P2F) Compute the Program 2 Factor: (P2 EU) _____ x (P2 ECF) _____ = _____ (P2F) Dual-Program Factor (DPF) Compute the Dual-Program Factor: (P1F) _____ + (P2F) _____ = _____ (DPF) Usage Correction Factor If using Continuous mode with 24 hours of stimulation, skip this step. Otherwise, calculate the Usage Correction Factor as follows: Hours of stimulation (per day): _____ hours Cycle On time: _____ Cycle Off time: _____ Compute the Usage Ratio: _____ hours of stimulation ÷ 24 hours = _____ And the Cycling Ratio: _____ cycle On ÷ (_____ cycle On + _____ cycle Off) = _____ With the Usage Ratio (UR) and the Cycling Ratio (CR), compute the Usage Correction Factor (UCF): (UR) _____ x (CR) _____ = _____ (UCF) Or if Cycling is not used: (UR) _____ = _____ (UCF) 69 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Appendix A: Battery Longevity Reference Information Longevity Estimate Now calculate the adjusted Energy Use: (DPF) _____ x (UCF) _____ = _____ (adjusted EU) The estimated battery longevity from Table 10 on page 73 is: __________ years 70 220822001 Rev X Pkg_R00a 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Table 8. Kinetra Neurostimulator Energy Use for 2 Active Bipolar Electrodes per Program for 24 Hours/Day Usage. Pulse Width Amplitude Rate 60 120 210 450 130 185 250 10 14 19 18 26 34 29 43 55 58 82 103 2.0 130 185 250 25 37 49 49 71 93 84 120 155 169 237 300 3.0 130 185 250 41 59 77 81 114 148 137 195 249 276 383 481 4.0 130 185 250 74 103 134 142 200 259 241 338 434 484 665 N/A 5.0 130 185 250 113 159 207 219 309 397 374 522 666 749 N/A N/A 6.0 130 185 250 162 227 292 315 441 564 536 743 N/A 1073 N/A N/A 7.0 130 185 250 222 312 400 432 603 774 735 1020 N/A N/A N/A N/A 8.0 130 185 250 293 409 524 569 795 1013 968 N/A N/A N/A N/A N/A 9.0 130 185 250 376 523 664 731 1014 N/A N/A N/A N/A N/A N/A N/A 10.0 130 185 250 480 673 856 933 N/A N/A N/A N/A N/A N/A N/A N/A 1.0 71 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Note: N/A in Table 8 refers to values that are not allowed by the clinician programmer. Refer to “High Output Interlocks” on page 49. Table 9. Kinetra Neurostimulator Electrode Correction Factor (ECF) Electrode Configuration Electrode Correction Factor Bipolar 1 Negative, 1 Positive 1.0 1 Negative, 2 Positive 1.3 1 Negative, 3 Positive 1.5 2 Negative, 1 Positive 1.3 2 Negative, 2 Positive 1.8 3 Negative, 1 Positive 1.5 Unipolar 1 Negative, Case Positive 1.8 2 Negative, Case Positive 2.8 3 Negative, Case Positive 3.5 4 Negative, Case Positive 4.2 72 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix A: Battery Longevity Reference Information Table 10. Kinetra Neurostimulator Longevity Estimates (Years) for Energy Use (EU). 73 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy Appendix B: MRI and Activa Therapy Introduction It is important to read this appendix in its entirety before conducting an MRI examination on a patient with any implanted Activa System component. Contact Medtronic at 1-800-707-0933 if you have any questions. Due to the number and variability of parameters that affect MRI compatibility, the safety of patients or continued functioning of Activa Systems exposed to MRI cannot be absolutely ensured. MRI systems generate powerful electromagnetic fields that can produce a number of interactions with implanted components of the Activa neurostimulation system. Some of these interactions, especially heating, are potentially hazardous and can lead to serious injury or death. However, with appropriate control measures, particularly with respect to the selection of MRI parameters and RF coils, it is generally possible to safely perform an MRI head scan on an Activa patient. In addition, Activa System components can affect the MRI image, potentially impacting the diagnostic use of this modality. The following information describes the potential interactions and control measures that should be taken to minimize the risks from these interactions. Implantation of an Activa Brain Stimulation w Contraindication: System is contraindicated for patients who will be exposed to Magnetic Resonance Imaging (MRI) using a full body transmit radio-frequency (RF) coil, a receive-only head coil, or a head transmit coil that extends over the chest area. Performing MRI with this equipment can cause tissue lesions from component heating, especially at the lead electrodes, resulting in serious and permanent injury including coma, paralysis, or death. 74 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy w Warnings: ■ Do not conduct an MRI examination on a patient with any implanted Activa System component until you read and fully understand all the information in this manual. Failure to follow all warnings and guidelines related to MRI can result in serious and permanent injury including coma, paralysis, or death. ■ In-vitro testing has shown that exposure of the Activa neurostimulator system to MRI at parameters other than those described in this guideline can induce significant heating at the lead electrodes or at breaks in the lead. Excessive heating may occur even if the lead and/or extension are the only part of the Activa System that is implanted. Excessive heating can result in serious and permanent injury including coma, paralysis, or death. ■ MRI examinations of patients with an implanted Activa System should only be done if absolutely needed and then only if these guidelines are followed. MRI should not be considered for Activa patients if other potentially safer diagnostic methods such as CT, X-ray, ultrasound, or other methods will provide adequate diagnostic information. ■ A responsible individual with expert knowledge about MRI, such as an MRI radiologist or MRI physicist, must assure all procedures in this guidelines are followed and that the MRI scan parameters, especially RF specific absorption rate (SAR) and gradient dB/dt parameters, comply with the recommended settings, both for the pre-scan (tuning) and during the actual MRI examination. The responsible individual must verify that parameters entered into the MRI system meet the guidelines in this appendix. ■ Do not conduct an MRI examination if the patient has any other implants or limiting factors that would prohibit or contraindicate an MRI examination. 75 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy # Cautions: ■ The neurostimulator, especially those without filtered feedthroughs such as the Itrel II Model 7424, may be reset or potentially damaged when subjected to an MRI examination. If reset, the neurostimulator must be reprogrammed. If damaged, the neurostimulator must be replaced. ■ MRI images may be severely distorted or image target areas can be completely blocked from view near the implanted Activa System components, especially near the neurostimulator. If the MRI targeted image area is near the neurostimulator, it may be necessary to move the neurostimulator to obtain an image, or use alternate imaging techniques. Do not remove the neurostimulator and leave the lead system implanted as this can result in higher than expected lead heating. ■ Carefully weigh any decision to perform magnetic resonance imaging (MRI) examinations on patients who require the neurostimulator to control tremor. Image quality during MRI examinations may be reduced, because the tremor may return when the neurostimulator is turned off. ■ If possible, do not sedate the patient so that the patient can provide feedback of any problems during the examination. ■ Monitor the patient during the MRI examination. Verify that the patient is feeling normal and is responsive between each individual scan sequence of the MRI examination. Discontinue the MRI immediately if the patient becomes unresponsive to questions or experiences any heating, pain, shocking sensations/uncomfortable stimulation, or unusual sensations. 76 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy Note: The MRI guidelines provided here may significantly extend the MRI examination time or prevent some types of MRI examinations from being conducted on Activa patients. General Information on MRI An MRI system produces three types of electromagnetic fields that may interact with implanted neurostimulation systems. All three of these fields are necessary to produce an MRI image. Each of these fields can also produce specific but different types of interactions with implanted neurostimulator systems. These fields include: ■ Static Magnetic Field. This is a steady state non-varying magnetic field that is normally always ON, even when no scan is underway. In a 1.5 Tesla MRI system, the static magnetic field is approximately 30,000 times greater than the magnetic field of the earth. ■ Gradient Magnetic Field. This is a low-frequency pulsed magnetic field that is only present during a scan. The gradient magnetic field can induce voltages onto the lead system that may result in unintended stimulation or functional interactions with the neurostimulator. ■ RF Field. This is a pulsed radio frequency (RF) field that is only present during a scan. It can be produced by a variety of transmission RF coils such as a whole body transmit coil or an extremity coil such as a transmit/receive head coil. Only a transmit/receive head coil should be used as the other RF coils can expose more of the lead system to RF energy, thereby increasing the risk of excessive heating and thermal lesions possibly resulting in coma, paralysis, or death. 77 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy MRI Interactions with Implanted Activa Systems MRI/neurostimulation system interactions are various, and the risk to the patient can range from minimal to severe. These interactions include the following: Heating – The MRI RF field induces voltages onto the lead system that can produce significant heating effects at the lead electrodetissue interface or at the location of any breaks in the neurostimulator lead system. Component heating from the MRI RF field is the most serious risk from MRI exposure. Failure to follow these MRI recommendations can result in thermal lesions possibly resulting in coma, paralysis, or death. Magnetic Field Interactions – Magnetic field interactions such as force and torque effects are produced by the static magnetic field. Any magnetic material will be attracted to the static magnetic field of the MRI. The force and torque effects may produce movement of the neurostimulator that can be uncomfortable to the patient, open a recent incision, or both. Activa System components are designed with minimal magnetic materials. Induced Stimulation – Gradient magnetic fields may induce voltages onto the lead system that may cause unintended stimulation. The voltage of the induced stimulation pulses is proportional to the time rate of change (dB/dt) of the gradient pulses, the effective loop area created by the neurostimulator lead system, and the location of the lead system with respect to the gradient coils of the MRI. 78 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy Effects on Neurostimulator Function – The static, gradient, and RF fields of the MRI may affect the neurostimulator operation and programming. The static magnetic field may cause the neurostimulator to turn ON or OFF if the neurostimulator uses a magnetically controlled switch that allows the patient to control stimulation by the application of a handheld magnet. Additionally, the MRI RF, static, and gradient fields may temporarily affect or disable other functions, such as telemetry or stimulation pulses. Parameters will need to be reprogrammed if the MRI causes a POR (Power On Reset) of the neurostimulator. Image Artifacts and Distortion – The neurostimulation system components, particularly the neurostimulator, can cause significant imaging artifacts and/or distortion of the MRI image, particularly if the neurostimulator components contain magnetic material. The neurostimulator can cause the MRI image to be completely blocked from view (i.e., signal loss or signal "void") or severely distorted within several inches of the neurostimulator. MRI Procedure Scope These MRI/neurostimulator exposure guidelines apply to Activa Systems comprising combinations of the following components: ■ Neurostimulator Models: Itrel II 7424, Soletra 7426, Kinetra 7428 ■ Lead Extension Models: 7495, 7482 ■ Lead Models: DBS 3387, 3389 Supervision A responsible individual such as an MRI radiologist or MRI physicist must assure these procedures are followed. If the MRI is operated by an MRI technician, it is strongly recommended the responsible individual verifies that the MRI recommendations are followed. 79 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy Preparation Do the following prior to performing an MRI examination on an Activa patient: 1. Inform the patient of the risks of undergoing an MRI. 2. Check if the patient has any other implants or conditions that would prohibit or contraindicate an MRI examination. Do not conduct an MRI examination if any are found. 3. Verify that all proposed MRI examination parameters comply with the “MRI Operation Settings” on page 82. If not, the parameters must be modified to meet these requirements. If this cannot be done, do not perform an MRI. 4. If the patient has implanted leads but does not have an implanted neurostimulator, perform the following steps: a. Wrap the external portion of the leads/percutaneous extensions with insulating material. b. Keep the external portion of the leads/percutaneous extensions out of contact with the patient. c. Keep the external leads/percutaneous extensions straight, with no loops, and running down the center of the head coil. 5. If the patient has an implanted neurostimulator, perform the following steps: a. Review the neurostimulator with a clinician programmer and print out a copy of the programmed parameters for reference. b. Test for possible open circuits by measuring impedance and battery current on all electrodes in unipolar mode (see Table 11). If an open circuit is suspected, obtain an x-ray to identify whether the open circuit is caused by a broken lead wire. If a broken lead wire is found, do not perform an MRI. 80 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy Table 11. Measurement Values Indicating Possible Open Circuits Neurostimulator Impedance Battery Current Itrel II Model 7424 >2000 Ω <10 µA Soletra Model 7426 >2000 Ω <10 µA Kinetra Model 7428 >4000 Ω <15 µA An MRI procedure should not be performed in a w Warning: patient with an Activa System that has a broken lead wire because higher than normal heating may occur at the break or the lead electrodes which can cause thermal lesions. These lesions may result in coma, paralysis, or death. c. If the Activa System is functioning properly and no broken lead wires are found, program the neurostimulator to the settings provided in Table 12. Table 12. Recommended Neurostimulator Settings for MRI Parameter Setting Stimulation output OFF (all programs) Stimulation mode Bipolar (all programs) Amplitude 0 Volts (all programs) Magnetic (reed) switch Disabled (Kinetra Model 7428 only) Other parameters Do not change 81 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy MRI Operation Settings Prior to the MRI examination, a responsible individual such as an MRI radiologist or MRI physicist must assure the examination will be conducted according to the following MRI requirements. If standard MRI pulse sequences will be used, they must meet these requirements. If they do not, the pulse parameters must be adjusted so that they comply with these requirements: In-vitro testing has shown that exposure of the w Warning: Activa System to MRI under conditions other than described in this guideline can induce excessive heating at the lead electrodes or at breaks in the lead to cause lesions. These lesions may result in coma, paralysis, or death. ■ Use only a 1.5 Tesla horizontal bore MRI (do not use open sided or other field strength MRI systems). ■ Use only a transmit/receive head coil. Implantation of an Activa Brain w Contraindication: Stimulation System is contraindicated for patients who will be exposed to Magnetic Resonance Imaging (MRI) using a full body transmit radio-frequency (RF) coil, a receive-only head coil, or a head transmit coil that extends over the chest area. Performing MRI with this equipment can cause tissue lesions from component heating, especially at the lead electrodes, resulting in serious and permanent injury including coma, paralysis, or death. ■ Enter the correct patient weight into the MRI console to assure the head SAR is estimated correctly. ■ Use MRI examination parameters that limit the head SAR to 4/ 10 (0.4) W/kg or less for all RF pulse sequences. 82 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy w Warnings: ■ ■ Ensure the SAR value is the value for head SAR. Some MRI systems may only display SAR, whole body SAR, or local body SAR. Make sure the value being limited to 4/10 (0.4) W/kg is for head SAR. Excessive heating may occur if the wrong SAR value is used. ■ If MRI parameters must be manually adjusted after the initial automatic MRI prescan, do not make any adjustments that will increase the SAR value. Some MRI machines may not automatically update the displayed SAR value if manual adjustments are made. This may lead to higher than expected temperature increases in the Activa System, particularly at the lead electrodes. Limit the gradient dB/dt field to 20 Tesla/second or less. Note: The recommendations provided are based on in-vitro testing and should result in a safe MRI examination of a patient with an implanted Medtronic Activa System. However, due to the many variables that affect safety, Medtronic cannot absolutely ensure safety or that the neurostimulator will not be damaged. The user of this information assumes full responsibility for the consequences of conducting an MRI examination on a patient with an implanted Activa System. Prior to the MRI Examination Prior to the scan examination, the responsible individual must verify the MRI examination parameters comply with these guidelines. ■ Patients with implanted Activa Systems should be informed of the risks of undergoing an MRI. 83 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Appendix B: MRI and Activa Therapy ■ If possible, do not use sedation so the patient can inform the MRI operator of any heating, discomfort, or other problems. ■ Instruct the patient to immediately inform the MRI operator if any discomfort, stimulation, shocking, or heating occurs during the examination. During the MRI Examination ■ Monitor the patient both visually and audibly. Check the patient between each imaging sequence. Discontinue the MRI examination immediately if the patient is unable to respond to questions or reports any problems. ■ Conduct the examination using only the MRI pulse sequence that the MRI radiologist or physicist has confirmed meets the MRI requirements above. Post MRI Examination Review ■ Verify that the patient is feeling normal. ■ Verify that the neurostimulator is functional. ■ Reprogram the neurostimulator to pre-MRI settings. 84 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Glossary Glossary Amplitude – A measure of the electrical intensity delivered in a stimulating pulse, measured in volts. Interference – Anything that reduces the effectiveness of the neurostimulator or a programming transmission. Mode – The type of stimulation that can be programmed. Parameter, Programmable – A specific function with an operating range of selectable values (i.e., Rate, Pulse Width) that enables the tailoring of neurostimulation therapy for a patient. Pulse Width – A measure, in microseconds, of the duration of each stimulating pulse. Rate – A measure, in pulses per second (or Hz), that provides the number of times stimulating pulses are delivered each second. SoftStart/Stop Stimulation – The SoftStart/Stop feature that allows stimulation to begin with a ramped output (e.g., it is designed to prevent a sudden “burst” of stimulation when the neurostimulator turns On normally). This is done by gradually increasing the amplitude of the stimulating pulses up to the programmed value. The SoftStart/Stop feature also causes a gradual decrease of the amplitude of stimulation back down to zero when the neurostimulator output is turned Off, or when the Off cycle begins. Telemetry – A radiofrequency type of communication. 85 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic Confidential Pkg_R00a Special Notice Special Notice Medtronic Neurostimulator kits consist of a neurostimulator and tools to connect the neurostimulator to implantable extensions. Neurostimulators are used with extensions, which are implanted in the extremely hostile environment of the human body. Neurostimulators may fail to function for a variety of causes, including but not limited to, medical complications, body rejection phenomena, or component failure. In addition, Neurostimulators and tools may be easily damaged by improper handling or use. For tools, Medtronic disclaims all warranties, both express and implied, including, but not limited to, any implied warranty of merchantability or fitness for a particular purpose. Medtronic shall not be liable to any person or entity for any medical expenses or any direct, incidental or consequential damages caused by any defect, failure or malfunction of any tool, whether a claim for such damage is based upon warranty, contract, tort or otherwise. No person has any authority to bind Medtronic to any representation or warranty with respect to tools. 86 220822001 Rev X 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) 220822001 Rev X Medtronic Confidential Pkg_R00a 7428_EN.FM 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) 220822001 Rev X Medtronic Confidential Pkg_R00a 7428_ENbcv.fm 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) 220822001 Rev X Medtronic Confidential package_R00a 7428_ENbcv.fm 12/15/03 4:06 pm UC200xxxxxx EN 4.625 x 6 inches (117 mm x 152 mm) Medtronic, Inc. 710 Medtronic Parkway Minneapolis, MN 55432-5604 USA Internet: www.medtronic.com Tel. 1-763-505-5000 Toll-free 1-800-328-0810 Fax 1-763-505-1000 220822001 Rev X Medtronic Confidential package_R00a © Medtronic, Inc. 2003 All Rights Reserved 220822001