| 摘要 |
<p>Components of an automatic digital blood pressure measurement system. There is provided a compact light-weight and electric blood pressure measurement system having digital display means of blood pressure. The system includes: 1. A hose microphone plug (4) integrally formed of a plug (12) of a microphone for Korotokov sounds detection, a rubber-made tube connector (5) to a cuff, and a rubber-made tube connector (16) to an air pump, whereby the microphone is isolated from the vibration of the air pump. 2. An automatic constant speed exhaust valve in which a rubber valve (18) having two holes (19) and (21) is placed in a holder (20) which is fixed inside a casing (25) by a low pressure valve (22). Thus, the fine adjustment of exhaust speed can be made by an adjust screw (24) and a coil spring (23) fixed to the low pressure valve (22), whereby automatic blood pressure measurement may be achieved. 3. An electronic circuit for regulating an air pressure converter against temperature changes and variation of supply voltage comprising: a constant current circuit consisting of a regulated reference voltage (31), and integrated circuit (34) and a semiconductor device (36), a semiconductor device (35) being controlled so that output (V6) may be kept constant by arranging the output (V5) of bridge circuit to be same potential as the ground (42). 4. An electronic switching circuit comprising a PNP transistor (55), a NPN-transistor (56), resistors and capacitors. ON/OFF operations of the switching circuit is associated with a combination of a timer circuit (67) and a diode (68), so that the power supply is disconnected after a predetermined time when no signal is applied, thereby preventing waste of power supply. 5. A ramp detecting circuit for low level signals of blood pressure measurement consisting of two diodes (70) and (71), an integrated circuit (69) for voltage comparison, resistors and capacitors, the diodes (70) and (71) being utilized to detect the changes of input signals by the comparison of forward voltage drops developed across the diodes, thereby improving the precision of blood pressure measurement. </p> |
