| abstract |
The invention relates to apparatus for measuring blood pressure by providing an inflatable cuff and pulse sensing means for fixing to a digit such as, for example, a finger or toe, and electrical control circuit means for converting a sense pulsed into a visual or audible indication, pneumatic means for transmitting the sensed pulse to the converting means and pressure means for measuring the pressure exerted in the cuff, the arrangement being such that with the cuff in a operative position on the body, progressive inflation/deflation of the cuff is effected until pulse sensing means just detect the presence of the pulse thus providing an indication of the systolic blood pressure. The invention includes novel variable capacitors for pneumatic coupling to the pulse sensor and comprising a housing, a diaphragm disposed across the housing, a base plate disposed on the side of the diaphragm opposite from said pneumatic connection, and electrical connecting means provided to the base plate so that changes in the volume occur the cavity defined by the base plate and the diaphragm due to pressure changes in the pneumatic system above the diaphragm, resulting in changes in capacitance and sensing of the pulse within the pneumatic system to be determined. |