GE DINAMAP ProCare 100, Service Manual

Page: 39 / 96

3-4 ProCare Patient Monitor Service Manual Revision A
2008381-001
Principles of Operation: 3.2 Overall Principles of Operation
3.2 Overall Principles of Operation
The following paragraphs provide a general system interface relationship.
The general block diagram is located in Figure 3-1.
The ProCare Monitor is a portable unit that receives input power from an
internal rechargeable battery.
When the ON/OFF button is pressed, the Main Board is brought out of a
sleep mode and turns on the power regulators. The power regulators provide
conditioned power from the Lead Acid Battery. The external DC source is
used only to charge the Lead Acid Battery. Once the
ProCare Monitor is
energized, a self-test is performed. The self-test automatically tests the main
functions of the
ProCare Monitor. Failure of the self-test will set the ProCare
Monitor into a fail-safe mode with an audio alarm.
Under normal operating condition, the ProCare Monitor is ready to record
the patient vital signs using three external attachments: the temperature
probe, SPO2 sensor, and cuff. Interface with a central station or other device
is accomplished through the host communication port on the back of the
ProCare Monitor.
3.2.1 SpO
2
(Model 300 and 400)
The SpO
2
probe has a built-in sensor. When the SpO
2
sensor is attached to
the SpO
2
connector and patient, the probe senses the heart rate and oxygen
saturation. The analog signals are routed to the SpO
2
PWA (Nellcor or
Masimo). The analog signals are analyzed on the SpO
2
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 SpO
2
PWA is also provided so that the power up
sequencing is corrected. If the SpO
2
circuit quits communicating to the Main
Board, the Main Board will attempt to reset the SpO
2
PWA.
3.2.2 Cuff Blood Pressure (BP) and Pulse
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.