Download Patient State Analyzer 4000 - University of Rhode Island

Patient State Analyzer 4000
Morgann Robitaille
Biomedical Engineering University of Rhode Island, Kingston, RI 02881
Did you know that over 290,000 times a year,
patients wake up during a surgical procedure and
are aware of their surrounding and even worse,
sometimes the pain? Over the past years,
anesthesiology has not only grown as a science but
also an art. It takes into account physical history and
condition, duration of surgery and from there, the
anesthesiologist chooses the appropriate drug to
control the hypnotic and paralytic requirements.
Before, without the use of equipment,
anesthesiologists had to use their knowledge of each
drug to decide how the patient is reacting and the
effects he or she will have. This often meant that a
patient could receive too much anesthesia, which
would prolong the recovery from the drug or too
little, making the patient awake and aware of their
surroundings. To reduce the risk factor of patients
coming back into consciousness, Physiometrix has
developed a system that can monitor the effects of
the anesthesia on the patient.
The Patient State Analyzer (PSA) 4000, is intended
to monitor the state of the brain by acquisition of
real-time data and processed EEG signals (Patient
State Index). Obtaining real-time data, heart rate
and blood pressure gives an exact real-time picture
of the patient's consciousness. The Patient State
Index (PSI) is measured using algorithms that are
plotted using numerical values and as a color-coded
historical display.
•
PSI values between 25-50 shows a green trend
which represents the patient is in sufficient
hypnotic state and has a low probability of
surgical recall.
•
Below 25 is shown in yellow, representing a
very deep sleep that may result in long recovery
from anesthesia.
•
Above 50, also in yellow, represents a
lightening hypnosis.
There are many advantages to using the PSA 4000
during surgical procedures. The system produces a
continuos output throughout the duration of the
procedure, which allows the anesthesiologist to be
aware of the patients state at all times. Being aware
of the state of hypnosis gives the anesthesiologist to
make changes in the drug being administered. For
example, the anesthesiologist can titrate drug levels
while in surgery to make sure of rapid patient wakeups while minimizing postoperative complications
in the PACU. They can also know when the patient
might becoming aware and therefore administer
more of the drug. Also because the PSA 4000 was
designed to be impervious to interference, the
anesthesiologist is aware at all times of the patient's
condition even during other patient manipulations.