| 摘要 |
An electromedical system comprises at least one sensor to be placed in a patient's armpit and a movable unit for wireless measuring of signals transmitted by the sensor. The sensor is composed of an oscillatory circuit L1 driven by a lower frequency oscillator. The oscillator in the form of an RC- oscillator comprises a symmetrically coupled feedback operational amplifier, the output signal of which controls the oscillatory circuit via capacitive diode D3. A bridge circuit containing parameter- sensitive elements e.g. pressure sensitive capacitor CV and temperature sensitive resistors RV1, RV2 is connected in the feedback loop of the amplifier, power to the oscillator being supplied over antennae L. Thus changes in the parameter sensitive elements change the pulse output frequency of the oscillator and hence the output from the oscillatory circuit will be a pulsating complex FM-signal which is picked up by a portable receiver. <IMAGE> |
