GE marquette MAC 1100, Инструкции по обслуживанию

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Marquette Hellige GmbH MAC 1100/1200 V 1.1 Page
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when the voltage control applies the signal REG_OFF_, because the battery
voltage gets too low during battery operation.
The Voltage Control controls the battery voltage during battery operation.
The signal BATT_LEV2 indicates that the battery charge has gone down, and the
device should be connected to the line power soon.
The signal BAT_LEV1 indicates that the battery has been discharged almost
completely, the device should be connected to the line power immediately, otherwise
the device will shut down within few minutes.
If battery discharge is continued without connecting to the line power, the signal
REG_OFF_ is activated and the device is switched off.
2.3.3 ECG recording and front-end processing
The patient input is classified as being cardiac floating and is defibrillation-proof.
The patient leads are connected with a 15-pin connector with a special form for the
specified and released patient cables for the MAC1100/1200.
The main element of the ECG recording and front-end processing is a set of chips
comprising 3 ASICs. Pace detection is realized by a separate circuit.
Every disconnected electrode is detected by a special AC measurement, which
allows higher impedance between electrode and patient.
N common-mode compensation ensures suppression of interference, at the same
time serving to improve the in-phase suppression of the input electrodes.
To protect patients, the ECG recording and front-end processing are assembled as
floating components. Digital signals from and to the controller core are transmitted
via opto-electronic couplers. The floating /- 5V is generated by an isolated
flyback converter from the + 5V logic power supply.