Abstract: A hearing aid has a circuit board having conductor strips thereon; first plug-in elements mounted on the circuit board and being electrically connected to selective conductor strips; a plurality of circuit board-supported modular structural units; and second plug-in elements mounted on each circuit board-supported modular structural unit. The first plug-in elements cooperate with respective second plug-in elements for securing selected circuit board-supported modular structural units on the circuit board.

Abstract: A blood pressure measuring procedure which can be performed by the subject employing a manually inflatable cuff and associated microphone, a measuring circuit responsive to signals having the form of Korotkoff sounds, a dual-indicator manometer having two individually controllable indicators, a control circuit for controlling the operation of the indicators, and a switch switchable between a pumping position in which it permits the cuff to be manually inflated and releases the indicators to respond to the cuff pressure and a measuring position in which the cuff pressure gradually decreases, one indicator is locked in its present position at the onset of Korotkoff sound signals and the other indicator is locked in its present position upon termination of Korotkoff sound signals. The subject places the cuff in position, moves the switch to its pumping position, inflates the cuff to a pressure above his systolic pressure, and then moves the switch to its measuring position.

Abstract: A dual-indicator manometer for an automatic sphygmomanometer, composed of two pressure indicators each mounted on a shaft and arranged to be individually blocked or released by the armature of an individual electromagnet. Depending on the excitation state of the electromagnet, the armature is raised from or pressed against the surface of the shaft of the associated indicator.