Service manual

4. BOARD/UNIT DESCRIPTION
4.10 Service Manual BSM-4100
The ECG RESP2 board has the high-pass filter (for 12 lead ECG), low-pass filter
(for 12 lead ECG) and polarization voltage detection circuit.
The lead for arrhythmia analysis is selected on this board. The ECG analog signal
on the selected lead for arrhythmia analysis goes to the ECG RESP3 board.
Since the respiration signal is proportional to the impedance between the two
electrodes, the respiration circuit sends a measurement status signal to the CPU on
the ECG RESP3 board according to the impedance level. The respiration circuit
has the high-pass filter so that the respiration waveform is obtained.
From ECG RESP 1 board
12 lead ECG I, II,
C1 to C6
High pass filter
Low pass
filter and
amplifier
x 18.1
150 Hz
−3 dB
Anti-
aliasing
filter
800 Hz
−3 dB
To ECG RESP 3 board
12 lead ECG
Reference clock (1 kHz)
PWM control signal
(Every lead) (500 Hz)
Polarization voltage
detection flag
Polarization voltage
detection circuit
(N, R, L, F, V1 to V6)
N, R, L, F
Respiration signal
Full wave rectifier
Low pass filter
High pass filter
Respiration measure signal
Respiration waveform
output
Analog signal output
ECG, HT, IBP
Composed leads
I, II, III, aVR, aVL, aVF
Lead
selector
I, II, III,
aVRLF
C1 to C6
Analog ECG
Pacing pulse
detection circuit
Pacing pulse
detection flag
C1 to C6
CAL
Calibration waveform generator
CAL control signal
R
C
R
R
R
Resolution
control