Signal Transmission; Heart-Rate Measurement - Marquette CardioServ Serviceanleitung

Marquette Hellige GmbH
* differential DC voltage compatibility ±1 V
* common-mode rejection (CMRR) R,L referred to
N 65 dB, N referred to chassis >110 dB
* trigger sensitivity 250 µV to 300 µV
* bandwidth .5 to 100 Hz
* patient leakage current: in normal condition
<10 µA, in single-fault condition <50 µA
* ground leakage current: in normal condition .
5 mA, in single-fault condition 1 mA
* voltage resistance referred to circuit reference
4 kV
* detection of pacing pulses
– pulse duration d
– pacemaker independent of polarity
– pulse amplitude a
– reverse-current pulse a
– time constant t
Signal display
backlit LCD, 2-channel erase bar mode, calibration
pulse in left-hand corner (for ECG)
alphanumeric presentation of alarm messages,
sensitivity, leads, systole blinker, alarm limits, heart
rate, energy and softkey labels
ECG freeze with simultaneous display of the current
ECG and (for modules with SpO
plethysmogram at a smaller scale
ECG trace 1.5 times larger than on recording: with a
sensitivity of 1 cm/mV a 1-mV signal has an ampli-
tude of 1.5 cm on the display
* erase bar sweep speed 25 mm/s
* trace length in real-time mode 4.6 s
* display dimensions: 115 mm wide, 86 mm high
CardioServ V. 3
> approx. 0.1 ms < 2.0 ms
p
±20 to ±700 mV
0
±1 mV
0
= 25 to 100 ms
0
function)
2
* resolution 320 x 240 pixels (pitch of .36 x
.36 mm)
* displayed image can be rotated 180 °

Signal transmission

signal input —> amplification —> signal sampling
—> AD conversion —> digital processing —>
LCD or recorder
* selectable sensitivity: .5-1-2 cm/mV (with max.
sensitivity of 2 cm/mV a 1-mV input signal is 2
cm in amplitude on the recorder and about 3
cm on the LCD), amplitude limited to approx.
±2 cm on the recorder and approx. ±3 cm on
the LCD
* signal sampling rate 1000 Hz
Systole check
* heart symbol flashing on the LCD
* QRS beep (can be disabled)

Heart-rate measurement

derivation of trigger pulses from the ECG of either
polarity, adaptive trigger threshold, calculation of the
average rate, storage of the result, 3-digit display on
LCD, alarm limits to the left of the reading:
* measuring range 15 to 300 BPM
* digit height of HR reading 7.5 mm
* digit height of alarm limits 2.5 mm
* min. amplitude for reliable triggering >.25 mV
for ECG signal with a QRS duration of 80 ms
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