Spo2 (Model 300 And 400); Cuff Blood Pressure (Bp) And Pulse; Principles Of Noninvasive Blood Pressure Determination - GE DINAMAP ProCare Service Manual

SpO (Model 300 and 400)
2

Cuff Blood Pressure (BP) and Pulse

Principles of Noninvasive Blood Pressure Determination

Revision C
Equipment Overview: Overall Principles of Operation
The SpO2 probe has a built-in sensor. When the SpO2 sensor is attached to the
SpO2 connector and patient, the probe senses both heart rate and oxygen
saturation. The analog signals are routed to the SpO2 PWA (Nellcor or Masimo).
The analog signals are analyzed on the SpO2 PWA. The results are digitized and
sent to the Main Board via opto couplers. The couplers provide patient isolation
as well as serial data interface. The Main Board temporarily stores the data and
routes it to the UI Board for display and/or printer.
A reset signal to the SpO2 PWA is also provided so that power up sequencing is
correct. If the SpO2 circuit quits communicating to the Main Board, the Main
Board will attempt to reset the SpO2 PWA.
The BP parameter in the ProCare Monitor is available with two types of DINAMAP
BP technologies: one calibrated to intra-arterial pressure and one calibrated to
the auscultatory method (specific technologies are available in select markets).
All user interface options, instructions for use, and alarms will be the same for
both technologies. The BP parameter is included in all models. Blood pressure is
monitored noninvasively in the ProCare Monitor by oscillometric method.
NOTE:For neonatal populations, the reference is always the intra-arterial
pressure monitoring method.
When the cuff and hose are attached to the ProCare Monitor and a Non-Invasive
Blood Pressure (NIBP) determination is initiated, the pump inflates the cuff.
Pressure transducers PT1 and PT2 monitor pressure information. The pneumatic
manifold has one valve, which is used to deflate the cuff. Valve control is through
the Main Board. Once determinations are made for the systolic BP and diastolic
BP, the Main Board calculates the pulse rate/ Mean Arterial Pressure (MAP). The
results are then displayed on the UI Board and sent to the printer (if specified).
The Pneumatic Valve/Manifold (PVM) device is controlled by the secondary
processor. The secondary processor monitors pressure information from PT2. If
an over-inflation condition occurs, the OVERPRESSURE signal is routed to the
PVM to release the air pressure. The Main Board also generates an alarm
condition with the speaker sounding and error code message on the UI Board.
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
®
DINAMAP ProCare Monitor Service Manual
2009381-001
2-9