An arrangement for connecting an electronic subassembly and an optical subassembly in an electro-optical communication device such as an electro-optical transceiver. The detector is a cardio-mechanical parameter detector that measures, as said physiologic parameter, a mechanical change in at least one of the four chambers of the heart. Input capacitance of the direct-current switch device works in conjunction with a switch input series resistor to avoid a sharp turn-on characteristic.