GE CareScape V100, Service Manual

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2048723-002C CARESCAPE V100 Vital Signs Monitor 2-11
Equipment overview: Overall principles of operation
The SuperSTAT algorithm evaluates the data obtained during the determination,
and the prior determination if it is available, to determine if additional data is
needed to complete the determination. It can then selectively pump to a single
cuff pressure to obtain the data it needs and then return to the existing deflation
sequence. This search process makes SuperSTAT more efficient.
Accuracy of the DINAMAP NIBP measurements was validated against the intra-
arterial method. Do not use the auscultatory method to verify the accuracy of
the SuperSTAT NIBP parameter. The auscultatory method (using the cuff and
stethoscope) determines the systolic and diastolic pressures from sounds that
occur during cuff deflation. Mean arterial pressure cannot be determined by the
auscultation method. The oscillometric method used with all DINAMAP
technologies determines systolic, mean and diastolic pressures from the
oscillation pattern that occurs in the cuff during deflation.
NOTE
Arrhythmias will increase the time required by the NIBP parameter to
determine a blood pressure.
DINAMAP Classic and auscultatory reference algorithm
The oscillometric method of determining NIBP is accomplished by a sensitive
transducer, which measures cuff pressure and minute pressure oscillations
within the cuff. The first determination sequence initially pumps up to a cuff
pressure of about 160 mmHg for adult/pediatric patients or 110 mmHg for
neonates depending on initial target pressure preset. After inflating the cuff, the
monitor begins to deflate it and measures systolic pressure, mean arterial
pressure, and diastolic pressure. When the diastolic pressure has been
determined, the monitor finishes deflating the cuff and updates the screen.
The monitor deflates the cuff one step each time it detects two pulsations of
relatively equal amplitude. The time between deflation steps depends on the
frequency of these matched pulses (pulse rate of the patient). However, if the
monitor is unable to find any pulse within several seconds, it will deflate to the
next step. The process of finding two matched pulses at each step provides
artifact rejection due to patient movement and greatly enhances the accuracy
of the monitor. The figure shows the NIBP determination sequence.
NIBP determination sequence (specific pressure values are examples only)
At each step the microprocessor stores cuff pressure, the matched pulse
amplitude, and the time between successive pulses. The stepped deflation and
matched pulse detection continues until diastolic pressure is determined or total