Five A/D Channels; Pulse Channel Filter; Inflation Pump; Bleed Valve - Datascope Accutorr Plus Service Manual

Theory of Operation
1.2.3.3

Five A/D channels

All channels are at 12-bit resolution and digitized at 101 Hz:
1. DC pressure
2. AC pressure (pulse)
3. Hardware over pressure transducer
4. Hardware over pressure cooperator reference
5. Battery voltage monitoring, when the Accutorr is in battery operation
1.2.3.4

Pulse Channel Filter

A high-pass filter is provided to isolate the pulsatile component from the DC cuff
pressure. This pulsatile component is digitized as the pulse channel. The gain of this AC
coupled channel is programmable in a manner consistent with the specified range of pulse
amplitudes.
1.2.3.5

Inflation Pump

A pump capable of inflating the cuff within the specified time limit.
1.2.3.6

Bleed Valve

A valve and control system capable of bleeding down the cuff pressure.
1.2.3.7

Dump Valve

A valve to rapidly discharge the residual cuff pressure at the end of the measurement
cycle.
1.2.3.8

Cuff Inflation Requirements

The cuff is initially inflated to a software-determined pressure dependent upon patient
size. In timer mode, it should be a predetermined increment, traditionally 50 mmHg (40
mmHg for Neonates) (determined by the CPU), above the previous systolic reading, after
the first measurement. The software detects error conditions in the pneumatic system such
as disconnected cuffs or kinked hoses. To reduce the possibility of over inflating the cuff,
the pump may be driven at a lower speed when pressurizing small neonatal cuffs. This is
achieved by pulse width modulating the pump control signal. Further control of the
neonatal inflation rate may be achieved by using the bleed valve to relieve some portion of
the pump's delivery.
Accutorr Plus Service Manual
CPU/NIBP Module Assembly with LCD Display
0070-10-0691 1 - 5