Blood pressure measurement by Riva:Rocci:Korotkoff method - uses switch for opening or closing valve for cuff and needles locked by signals from Korotkoff noise

摘要

For blood pressure measurement, a two-way switch initiates a first pumping position, in which the cuff valve is closed and the cuff (1) pumped up. A battery-fed supply (32) circuit is switched on, the needles of a twin-needle manometer (23) are unlocked by exciting an electromagnet, and an electronic interlock for preventing needle locking is switched on. After the cuff is pumped up, the switch moves to its second position, in which the valve is opened, the interlock is switched off, the needles are locked by signals produced when the Korotkoff sounds start or stop and interrupting current for the electromagnets, and the supply circuit is switched off.