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Measurements with the Dual Pressure Sensor
If using the dual pressure sensor no additional connection between SOMNO HD
TM
and the
mask is necessary. The dual pressure sensor is connected directly to the pneumotachograph
and the cable is connected to the main device.
Additional Sensors
Sensor for recording the electrodermal activity (EDA Sensor)
The electrodermal activity is used to describe electrical phenomena of the skin because the
electro dermal response is correlating with the perspiratory gland.
For measuring the electrodermal activity a DC voltage is applied to the skin and the current is
hold constant. Then, the recorded voltage between the two electrodes is proportional to the
skin resistance.
The sensor can be plugged into any of the plugs of the main device.
Connecting the EDA sensors
In preparation for the recording the patients need to wash their hand with lukewarm water.
Make sure, the patient does not use soap, because then the epidermis is swelling and resulting
in a lowering of the signal. Furthermore, check that the electrodes are not place in areas with
cornea.
Intercostal EMG Sensor (IC-EMG Sensor)
The IC-EMG sensor is an electromyography sensor (EMG), which is used to record the muscle
activity in the intercostal area directly. The voltage difference between two electrodes on the
skin surface is recorded. The electrodes need to be orientated in the direction of the muscle
fibers. With this sensor central and obstructive apnea can be classified clearly.
EDA sensor
disposable electrodes