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Group2, UG, Rev2 A Pace Ahead MODEL THREE-MODE RATE ADAPTIVE CARDIAC PACEMAKER User Guide Group 2 Chatterjee, Kalyan – 0259250 Das, David – 0358484 Mahmood, Asim – 0252904 Park, Hyo-min – 0375695 APA-SE4G06-2 User Guide REQUIRED HARDWARE The pacemaker board Pacing leads – either coax as show below for the BNC connectors or just wire connectors to use on the binding posts 9-12 Volt A/C Power Adapter that provides at least 200mA 2 APA-SE4G06-2 User Guide USB to serial Connector (shown below) or a Serial cable with a DB-9 connector. Laptop or Desktop PC running 32-bit Windows XP or Vista 3 APA-SE4G06-2 User Guide TABLE OF CONTENTS LIST OF FIGURES ................................................................................................. 6 LIST OF TABLES .................................................................................................. 6 1 INTRODUCTION .................................................................................................. 7 1.1 Background ........................................................................................................................... 7 1.1.1 What is a pacemaker? ........................................................................................ 7 1.1.2 Device Overview................................................................................................. 7 1.2 Assumptions ......................................................................................................................... 8 1.3 Definitions, Acronyms, and Abbreviations ................................................................... 9 1.4 Document Conventions.................................................................................................... 10 2 QUICK START GUIDE ....................................................................................... 12 2.1 Important to Note ............................................................................................................... 12 2.2 Safety .................................................................................................................................... 12 2.3 Minimum System Requirements .................................................................................... 12 2.4 Setup Time ........................................................................................................................... 12 2.5 Installing the Pacemaker Software................................................................................ 13 2.6 Connecting the Pacemaker to your Computer........................................................... 20 2.6.1 Quick Setup – Advanced Users ........................................................................ 20 2.6.2 Detailed Setup Instructions ............................................................................... 21 2.6.3 Hardware Detected/Undetected........................................................................ 23 2.7 Connecting the Pacing Leads ........................................................................................ 24 2.8 Using the Pacemaker Software ...................................................................................... 26 2.8.1 Logging In......................................................................................................... 26 2.8.2 Creating a New Client ....................................................................................... 26 2.8.3 Initial Configuration ........................................................................................... 27 2.8.4 Knowing the User Interface .............................................................................. 29 3 PACEMAKER PARAMETER CONFIGURATION .................................................. 31 3.1 Changing Parameters ....................................................................................................... 31 Error Checking on Input Values ................................................................................. 34 3.2 Event Histogram and Electro Cardiogram .................................................................. 35 3.4 Panic Button........................................................................................................................ 36 3.4 Ending a Session ............................................................................................................... 36 4 STORING YOUR PACEMAKER SYSTEM ........................................................... 37 5 CONTACT US.................................................................................................... 38 4 APA-SE4G06-2 User Guide 6 TROUBLESHOOTING ........................................................................................ 39 APPENDIX ........................................................................................................... 41 Pacemaker Modes .................................................................................................................... 41 VVI mode .................................................................................................................. 42 DDD mode ................................................................................................................ 43 DDDR mode .............................................................................................................. 45 INDEX .................................................................................................................. 46 5 APA-SE4G06-2 User Guide LIST OF FIGURES Figure 1 - Pacemaker System Overview Schematic ........................................................... 8 Figure 2 - Creating a Desktop Shortcut ............................................................................ 11 Figure 3 – Installation Welcome Screen ........................................................................... 14 Figure 4 – Select Installation Folder ................................................................................. 15 Figure 5 – Installation Progress ........................................................................................ 16 Figure 6 – Installation Confirmation................................................................................. 17 Figure 7 - Desktop Shortcut .............................................................................................. 17 Figure 8 - PC Connection ................................................................................................. 21 Figure 9 - Serial Port on the Pacemaker board ................................................................. 21 Figure 10 - Serial Cable Connection ................................................................................. 22 Figure 11 - USB Connection to your PC .......................................................................... 22 Figure 12 - Hardware Detection Notification ................................................................... 23 Figure 13 – Step 1 – Locate the pacemaker ports as shown above................................... 24 Figure 14 – Step 2 – Connect one end of each pacing lead to the Atrial and Ventricle ports................................................................................................................................... 25 Figure 15 - Your pacemaker system should look this at this point ................................... 25 Figure 16 – Login Window ............................................................................................... 26 Figure 17 - Pacemaker User Interface I ............................................................................ 27 Figure 18 - Pacemaker ID not entered .............................................................................. 28 Figure 19 - Pacemaker ID not found on Database ............................................................ 28 Figure 20 - Serial Port Error ............................................................................................. 29 Figure 21 - Knowing your Pacemaker System User Interface ......................................... 30 Figure 22 - Mode VVI ...................................................................................................... 31 Figure 23 - Mode DDDR .................................................................................................. 32 Figure 24 - Changing a parameter value ........................................................................... 32 Figure 25 - Error check on input values............................................................................ 34 Figure 26 - Real-Time Event Histogram and ECG ........................................................... 35 Figure 27 - Panic Button ................................................................................................... 36 Figure 28 - Anti-Static Storage Box ................................................................................. 37 Figure 29 - Windows Device Manager ............................................................................. 39 Figure 30 - Install missing drivers .................................................................................... 40 LIST OF TABLES Table 1: Bradycardia Operating Modes ......................................................................... 41 6 APA-SE4G06-2 User Guide 1 Introduction 1.1 Background If you are an expert in pacemakers you may skip this section. However, it is recommended that the user reads section 1.1.2 to get an overview of the device. 1.1.1 What is a pacemaker? A pacemaker is a medical device which uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart’s native pacemaker is not fast enough, or there is a block in the heart’s electrical conduction system. The pacemaker software is embedded in a pacemaker hardware device which is implanted along with leads by physicians and hospital staffs with varying degrees of experience. Follow-up with the patients is typically performed by nurses or technicians under the supervision of a physician. 1.1.2 Device Overview A Pace Ahead pacemaker system is designed to train medical practitioners about various pacemaker parameters. Specifically, the system allows a user to change different pacemaker parameters in order to study the effect of those changes on a patient’s heart condition. Any real life heart condition could be emulated using a software package like National Instrument’s ©LabVIEW, which is then sensed by the pacemaker hardware. The software provides a dynamic graphical user interface which provides a real-time histogram of various heart parameters and also an Electro Cardiogram (ECG). The pacemaker needs to be connected to a computer with a RS232 port. 7 APA-SE4G06-2 User Guide ste Sy m a St rt- VVI up Fail-Safe VVI Mode Mode Y Mode Z Mode X Configuration Change Via USART USART Start Mode Figure 1 - Pacemaker System Overview Schematic As soon as the Pacemaker System is wired to the heart and turned on, the Pacemaker Software will operate under default mode which is fail-safe mode. A specific mode can be programmed on-the-fly via the port connection. Once put in any mode, it will stay in that mode until it detects a system failure or an operator sends it parameters to change the mode. At any of these points, it will return instantly to Fail-Safe Mode. The three pacemaker modes that could be programmed with this model are VVI, DDD and DDD-R. For further information on the pacemaker modes please see Pacemaker Modes . 1.2 Assumptions The document assumes the user’s familiarity with the following: 1. Basic PC operations (Don’t worry, the setup is really easy!) 2. A Pacemaker ID is known. Required in this step 8 APA-SE4G06-2 User Guide 1.3 Definitions, Acronyms, and Abbreviations Accelerometer AP AS ARP ATR AV BOL BPM cc CCI DCM ECG EGM EOL EP ERN ERT HRL ICD IS-1 LRL LRI MSR NSR OR PG PIC POR PMT ppm PVARP PVC QRS Rate smoothing Rate response SIR SRD URL URI VP VS VRP A device that detects and measures acceleration and tilt Atrial Pace Atrial Sense Atrial Refractory Period Atrial Tachycardia Response Atrial-to-Ventricular Beginning Of (battery) Life Beats Per Minute Cardiac Cycle(s) Cardiac Cycle Interval Device Controller-Monitor Electrocardiogram, external heart signals Electrogram, internal heart signals End Of (battery) Life Electrophysiology, electrophysiologist Elective Replacement Near Elective Replacement Time Hysteresis Rate Limit Implantable Cardio-Defibrillator Industry Standard lead type 1 Lower Rate Limit Lower Rate Interval Maximum Sensor Rate Normal Sinus Rhythm Operating Room Pulse Generator Programmable Integrated Circuit Power-On Reset Pacemaker-Mediated Tachycardia Pulses Per Minute Post-Ventricular Atrial Refractory Period Premature Ventricular Contraction Electrical shock instigation of the heart’s contraction cycle Rate modulated based on the heart’s pacing rate Rate modulated based on the accelerometer Sensor Indicated Rate Sustained Rate Duration Upper Rate Limit Upper Rate Interval Ventricular Pace Ventricular Sense Ventricular Refractory Period 9 APA-SE4G06-2 User Guide 1.4 Document Conventions The following symbols are used throughout the document. They are defined here for your convenience. (i) - Wherever this sign is found on the document, please keep a note of the information you are requested. It may come handy while trouble troubleshooting various issues or in time of emergency (ii) (iii) - Safety hazard - Caution must be exercised to avoid damage to the device iv) - Error Messages (v) A procedure like Figure 2 is written as: “CLICK on START RIGHT-CLICK “A Pace Ahead” SELECT Send To’ ” ‘Desktop’ 10 APA-SE4G06-2 User Guide Figure 2 - Creating a Desktop Shortcut 11 APA-SE4G06-2 User Guide 2 Quick Start Guide The following sub-sections should be read carefully as they contain all the necessary information for setting up the pacemaker board. Please note that in this document, the pacemaker board will be referred to as the ‘unit’. 2.1 Important to Note If you have any particular questions, please read through the 6 Troubleshooting section. It answers most issues you may encounter. If you need help at any point during the installation process please email [email protected] 2.2 Safety Like with any electrical device, there is a hazard of electrical shock. Please refrain from touching pacemaker components while it is powered ON. 2.3 Minimum System Requirements A Windows PC (2000/Me/XP/Vista) running .NET version 3 framework Pentium II 400 MHz or equivalent 256 MB of RAM 50 MB of free HDD Space CD-ROM Drive USB port 2.4 Setup Time It should take 10 to 20 minutes to set up the pacemaker system and install the pacemaker software on an average performance ©Windows PC. 12 APA-SE4G06-2 User Guide 2.5 Installing the Pacemaker Desktop Software and Board Firmware 2.5.1 Installing the Pacemaker Desktop Software Step 1 DOWNLOAD the zip file containing the Desktop GUI software GUI Installation.zip From http://www.cas.mcmaster.ca/~lawford/Pacemaker Step 2 SELECT “Open” the zip file. Step 3 DOUBLE-CLICK on the file named setup.exe to open the application installer 13 APA-SE4G06-2 User Guide Figure 3 – Installation Welcome Screen Step 4 CLICK on ‘Next’ after you have read the copyright infringement warning (as in Figure 3) Step 5 CLICK on ‘Browse’ (Figure 4) to select an installation directory ( important: make a note of this location). SELECT ‘Just me’ if other users on the computer do not need to use the APA software. CLICK on ‘Next’ to proceed. 14 APA-SE4G06-2 User Guide Figure 4 – Select Installation Folder Step 6 Make changes (if any) to the installation settings by clicking on the ‘Back’ button, else CLICK on ‘Next’ to proceed with installation. The installation (as shown in Figure 5) takes a minute or two. 15 APA-SE4G06-2 User Guide Figure 5 – Installation Progress Step 7 Once the installation completes, a confirmation (Figure 6) is displayed. CLICK ‘Close’ to complete the installation. 16 APA-SE4G06-2 User Guide Figure 6 – Installation Confirmation Step 8 Ensure that there is a desktop shortcut (as in Figure 7) for the application Figure 7 - Desktop Shortcut 17 APA-SE4G06-2 User Guide No Desktop icon? Browse to your installation directory (that you noted in Step 5 of this section) and RIGHT-CLICK on the icon than says “4G06Group2.exe”, SELECT “Send To Desktop”. This should create a shortcut like Figure 7 on the desktop. 2.5.2 Installing the Pacemaker Board Firmware Step 1 DOWNLOAD the zip file containing the Microcontroller software MicrocontrollerSource.zip From http://www.cas.mcmaster.ca/~lawford/Pacemaker Step 2 RIGHT CLICK on the zip file and select “Extract All …”. This will create a Directory called MicroControllerSource. Step 3 START Microchip’s MPLAB IDE and se on the zip file and SELECT “File Open Workspace …” and then navigate to the MicroControllerSource directory and open the file “Group2SE4G06.mcw”. Ignore warnings about missing source files (only the binary for the firmware is contained in the zip file). 18 APA-SE4G06-2 User Guide Step 4 CONNECT the programmer to the board as shown below. Cables are supplied for the IDC2 and the PICKit2 with the Pacemaker Board. Step 5 SELECT the correct programmer (e.g. ICD2 or PICKit2” from the “Programmer Select Programmer” entry. Step 6 CONNECT to the programmer in the MPLAB IDE by SELECT “Programmer Connect”. Step 7 19 APA-SE4G06-2 User Guide PROGRAM the board from the MPLAB IDE via SELECT “Programmer Program” Step 8 DISCONNECT programmer and from the board and exit the MPLAB IDE. 2.6 Connecting the Pacemaker to your Computer 2.6.1 Quick Setup – Advanced Users While the pacemaker board is not connected to a power source, CONNECT the serial port of the pacemaker board to your computer’s USB port using the USBSerial Connector provided with the pacemaker system. ENSURE the serial cable is properly screwed to the pacemaker board. Connect the pacemaker to the power source. Attempting to connect the pacemaker to the computer while the pacemaker is powered ON may result is permanent damage to the system. 20 APA-SE4G06-2 User Guide Figure 8 - PC Connection 2.6.2 Detailed Setup Instructions Follow the steps shown below to connect the pacemaker system to your computer. 1. Locate the serial port on the pacemaker. Figure 9 - Serial Port on the Pacemaker board 21 APA-SE4G06-2 User Guide 2. Connect the serial end of the USB-serial connector to the serial port of the pacemaker as shown below. Figure 10 - Serial Cable Connection 3. Connect the USB cable to any free USB port on your Windows PC. Figure 11 - USB Connection to your PC I 22 APA-SE4G06-2 User Guide Step 2 CONNECT the pacemaker board to the power source using a 9 to 12V AC power adapter with at least 200mA. You can even run the board off of a 9V radio battery, but please ensure that the connections have the correct polarity: The center is the positive voltage and the outer connector is the ground. 2.6.3 Hardware Detected/Undetected If your computer detects the pacemaker device you should see a notification on your Windows taskbar (Figure 12) Figure 12 - Hardware Detection Notification 23 APA-SE4G06-2 User Guide Please refer to Troubleshooting if your computer did not detect the pacemaker system or failed to install it properly. 2.7 Connecting the Pacing Leads (Optional) CONNECT the pacemaker leads as shown in the illustrative steps below if you want to connect a signal generator and/or an oscilloscope. The black screw terminal(s) is board ground corresponding to the outer ring of the BNC connectors. The red screw terminals are for the ventricle and atrial inputs/outputs and correspond to the respective centre connectors of the BNC connectors. Figure 13 – Step 1 – Locate the pacemaker ports as shown above 24 APA-SE4G06-2 User Guide Figure 14 – Step 2 – Connect one end of each pacing lead to the Atrial and Ventricle ports Figure 15 - Your pacemaker system should look this at this point 25 APA-SE4G06-2 User Guide 2.8 Using the Pacemaker Software 2.8.1 Logging In DOUBLE-CLICK on the “A Pace Ahead” icon on your DESKTOP which brings up the login window (as in Figure 16). Figure 16 – Login Window The factory default username and password is admin and letmein respectively. Enter Username and Password and CLICK OK. You should see the main user interface as in Figure 17 - Pacemaker User Interface I. 2.8.2 Creating a New Client Please see the list of possible errors in section 2.8.3 26 APA-SE4G06-2 User Guide 2.8.3 Initial Configuration SELECT the COM PORT number from the dropdown menu labeled “Port”. In Figure 17 we have selected port COM3. ENTER a valid pacemaker ID in the field “PacemakerID” – NOTE: The default in the firmware is 65535. Due to a bug in the desktop software you may need to delete some spaces in this field before entering “65535” CLICK on “Connect” Figure 17 - Pacemaker User Interface I 27 APA-SE4G06-2 User Guide Possible Setup Errors If you leave the “PacemakerID” field blank and click Connect, the following error message is displayed. Figure 18 - Pacemaker ID not entered Please enter a Pacemaker ID before clicking on Connect. If you enter an invalid pacemaker ID, that is, a Pacemaker ID not on the database, the following error message is displayed. Figure 19 - Pacemaker ID not found on Database If you made an error, click “No” and enter the correct Pacemaker ID and try again 28 APA-SE4G06-2 User Guide If you were trying to create New Client - The current version of this software only allows you to access clients who are in the database. However, if you wish to enter a new user in the database, the only way to do that with the current software version, is to CLICK “Yes” in the prompt shown in Figure 19 and enter the new client ID in the “PacemakerID” field (Figure 16) and enter If a wrong COM PORT is selected an error message is displayed as in Figure 20. Figure 20 - Serial Port Error Select the correct COM PORT from the “Port” drop down menu (Figure 17) 2.8.4 Knowing the User Interface Upon successful setup you should see the following screen (Figure 21). User and Client information has been labeled for quick reference. PANIC Button – Please see section 3.4 Panic Button for the functionality of the PANIC button 29 APA-SE4G06-2 User Guide Figure 21 - Knowing your Pacemaker System User Interface 30 APA-SE4G06-2 User Guide 3 Pacemaker Parameter Configuration 3.1 Changing Parameters The pacemaker system currently supports three pacemaker modes – VVI, DDD and DDD-R. Figure 22 and Figure 23 show modes VVI and DDDR with different parameter values. Figure 22 - Mode VVI 31 APA-SE4G06-2 User Guide Figure 23 - Mode DDDR The user interface is designed to minimize the risk of wrong input. Therefore, keyboard input is not allowed. To enter a value you need to use the UP/DOWN buttons or the pink slide bar (Figure 24). Figure 24 - Changing a parameter value 32 APA-SE4G06-2 User Guide SELECT the ‘Configuration’ tab and you will see a screen like Figure 23 above with a certain mode (DDDR in this figure) USE the drop down menu labeled ‘Pacemaker Mode’ to select other configurable modes CLICK the UP or DOWN arrow button (Figure 24) to increase or decrease a particular parameter value. Lower Rate Limit is shown here. Alternatively, PRESS and HOLD the LEFT-MOUSE button at point A (Figure 24) and traverse along the pink slide bar region towards B to increase a value. To decrease a parameter value perform the same action, but this time start at B and move towards A 33 APA-SE4G06-2 User Guide Error Checking on Input Values The user interface also provides simple error checking on the parameter values to ensure consistency. The figure below shows a warning message that displayed when the user selected a higher value for Lower Rate Interval than the Upper Rate Interval. Figure 25 - Error check on input values 34 APA-SE4G06-2 User Guide 3.2 Event Histogram and Electro Cardiogram The user interface provides Real-Time Event Histogram of four heart events – Atrial Sense (AS), Atrial Pace (AP), Ventricle Sense (VS) and Ventricle Pace (VP). Please see the “Real Time ECG” Figure 26. Figure 26 - Real-Time Event Histogram and ECG 35 APA-SE4G06-2 User Guide 3.4 Panic Button The Panic button is provided for use in case of emergency only. In a situation where a patient does not feel comfortable with the updated pacemaker settings, CLICK on the panic button (see Figure 27) to revert to FAIL SAFE Mode (schematic shown in Figure 1) which restores default parameter values that would help stabilize the patient’s heart condition. Figure 27 - Panic Button 3.4 Ending a Session CLICK on the ‘Disconnect’ button (Figure 21) before powering OFF the pacemaker unit. 36 APA-SE4G06-2 User Guide 4 Storing Your Pacemaker System The pacemaker board consists of numerous delicate electronic components. To make sure that your pacemaker system functions properly for many years, always store it at room temperature in a dry place and inside an anti-static package such as the one that originally came with the system. Figure 28 - Anti-Static Storage Box 37 APA-SE4G06-2 User Guide 5 Contact Us If you are having trouble getting the pacemaker board working, e-mail Mark Lawford at [email protected]. You can also check out the Pacemaker Wiki at: http://www.cas.mcmaster.ca/wiki/index.php/Pacemaker 38 APA-SE4G06-2 User Guide 6 Troubleshooting “My Pacemaker System was not detected by the computer.” This most likely means that you do not have the proper driver for Serial-USB connector installed on your system. There are two actions you could take to resolve this issue. Action 1 Use Windows Automatic hardware driver update utility (Windows XP/Vista) RIGHT-CLICK on ‘My Computer’, SELECT ‘Properties’ and from the ‘System Properties’ window, SELECT the ‘Hardware’ tab. This will take you to the device manager as shows in Figure 29. Figure 29 - Windows Device Manager 39 APA-SE4G06-2 User Guide CHECK for entries that say “Other Device”. EXPAND and SELECT ‘Update driver’ to download and necessary drivers required for Serial-USB connector (Figure 30). Figure 30 - Install missing drivers RESTART YOUR COMPUTER Note: This requires that you are connected to the internet. 40 APA-SE4G06-2 User Guide APPENDIX Pacemaker Modes This chapter briefly explains various pacemaker modes. It’s a good idea to familiarize yourself with pacemaker modes if you are not sure what they mean. If you look at Table 1 below, it shows the various pacemaker modes. The pacemaker mode letters correspond to columns of Table 1. Table 1: Bradycardia Operating Modes Category Letters I II III IV (optional) Chambers Paced Chambers Sensed Response To Sensing Rate Modulation O-None O-None O-None A-Atrium A-Atrium T-Triggered V-Ventricle V-Ventricle I-Inhibited D-Dual D-Dual D-Tracked: Dual (T & I) For example, VVI would mean: Column I = V – Ventricle Column II = V – Ventricle Column III – I – Inhibited DDD would mean: Column I = D – Dual (both Ventricle and Atrium) Column II = D – Dual Column III – D – Dual Note: D is column II and III have different meaning. 41 R-Sensor Driven Rate Modulation APA-SE4G06-2 User Guide DDD-R would mean: Column I = D – Dual Column II = D – Dual Column III – D – Dual Column IV – R-Sensor Driven Rate Modulation VVI mode Ventricle Ventricle Inhibited, henceforth VVI, mode operates as it paces, and senses ventricle with inhibited response. Most of the time, the pacemaker will operate under standby mode, and paces heart only when spontaneous QRS complex is not sensed. Use Case: determine spontaneous QRS complex Brief Description There are mainly two valid types of QRS complex: paced QRS and spontaneous QRS. While hardware may not distinguish differences between spontaneous QRS outside blanking/refractory period and those occurring inside the period, software must be able to determine validity of the spontaneous QRS complex; spontaneous QRS sensed during the blanking/refractory period must be discarded. Use Case: determine wait time interval Brief Description During VVI mode, spontaneous QRS complex sensed from ventricle will put the pacemaker into standby mode to conserve battery life. Otherwise, the pacemaker must 42 APA-SE4G06-2 User Guide wait for the determined interval (escape interval + hysteresis value) before pacing heart manually. Additionally, if the heart rate increases or decreases then the pacemaker must accommodate this change by applying rate smoothing with programming rate value. Rate smoothing will be bounded by upper rate limit and lower rate limit to prevent too low or high heart rate. (Please refer to 1.3 Definitions, Acronyms, and Abbreviations for the difference between Rate smoothing and Rate response) DDD mode Dual Dual Dual (sometimes denoted as double), henceforth DDD, mode operates as it paces, and senses both atrial and ventricle with dual (triggered and inhibited) response. Most of the time, the pacemaker will operate under standby mode, and paces hearts only when spontaneous QRS complex from atrial and/or ventricular is not sensed. General rule of thumb, atrial QRS complex must be followed by ventricular QRS complex, whether paced or sensed. Use Case: determine spontaneous atrial QRS complex Brief Description There are mainly two types of QRS complex: paced QRS and spontaneous QRS. While hardware may not recognize the differences between two, software must be able to determine spontaneous QRS complex. Use Case: determine spontaneous ventricular QRS complex Brief Description There are mainly two types of QRS complex: paced QRS and spontaneous QRS. While hardware may not recognize the differences between two, software must be able to determine spontaneous QRS complex. 43 APA-SE4G06-2 User Guide Use Case: determine wait time interval (applies to both atrial and ventricular QRS complex) Brief Description Under DDD mode, whenever spontaneous QRS complex is sensed, the pacemaker must hold for the specific interval before determining the needs of manual pacing. Each successive spontaneous QRS complex will put the pacemaker into standby mode to conserve battery life. There are seven parameters to be considered upon adjusting wait time interval. These are: AVI (AV interval), PVARP (postventricular atrial refractory period), TARP (total atrial refractory period), AEI (atrial escape interval), PAVB (postatrial ventricular blanking), VSP (ventricular safety pacing window), VRP (ventricular refractory period), LRI (lower rate interval), and URI (upper rate interval). Use Case: Standby or Pace Brief Description Under DDD mode, manual pacing of atrial must be performed when AEI has passed since followed by ventricular QRS complex; otherwise pacing of atrial is withheld. Additionally, manual pacing or sensing of atrial QRS complex must be followed by a ventricular QRS complex after AVI has passed; this is valid only if URI has not passed yet, and otherwise AVI will be extended to restrict the pacing interval within URI. On the other hand, successive ventricular QRS complex must be sensed within LRI, and otherwise manual pacing must be performed. 44 APA-SE4G06-2 User Guide DDDR mode Dual Dual Dual Rate modulation (sensor driven) henceforth DDD-R, mode operates as an extension of DDD mode described above. DDDR inherits all functionalities (use cases) from DDD and extends it by using accelerometer to detect body movement. The pacemaker then uses this measurement of body acceleration to modulate rate smoothing. Accelerometer is used to mediate the rate response in the pacemaker. The pacemaker, thus, can increase or decrease the rate of pacing depending on the degree of body movement. Additional Use Case (in addition to DDD mode): detect and measure vibration in the body Brief Description When the pacemaker detects increased or decreased vibration in the body, it adjusts the pacing interval accordingly in order to cope with body movements. The pacing rate may accelerate or decelerate based on the measurement of vibration. 45 APA-SE4G06-2 User Guide Notes Index —A— —L— Abbreviations, 12 Accelerometer, 12 Acronyms, 12 anti-static package, 38 LabVIEW, 10 —C— New Client, 27, 30 —M— Minimum System Requirements, 15 —N— —P— COM PORT, 28 customer help line, 15 Pacemaker, 10 pacemaker board, 5 pacemaker ID, 28 Pacing leads, 5 PANIC, 30 Permanent Configuration, 34 product upgrade information, 15 —D— DDD, 11, 43, 45 DDD-R, 11, 32, 44, 47 default password, 27 username, 27 —R— Definitions, 12 Desktop icon, 21 desktop shortcut, 20 driver, 40, 41 registration, 6, 15 —S— Setup Errors, 29 slide bar, 33 —E— —U— ECG. See Electro Cardiogram Electro Cardiogram, 10 USB Connector, 6 USB-serial connector, 23 Use Case, 44, 45, 46, 47 —F— Fail-Safe Mode, 11 FDA, 2 Feedback, 39 —V— VVI, 11, 32, 43, 44 —K— keyboard input, 33 46