Automatic blood pressure monitor having reduced data loss sensitivity to cuff pressure changes

摘要

An automatic blood pressure monitor (10) having a blood pressure cuff (12), an air pump (16) applying pressurized air to the cuff (12), an air valve (18) selectively venting the cuff (12), and a pressure transducer (20) generating an output signal having a D.C. component indicative of the steady-state pressure in the cuff, and an A.C. component indicative of oscillometric pulses. The pressure transducer (20) output is amplified and applied to an analog-to-digital converter (24) which generates a digital word indicative of the steady-state cuff pressure. The amplified pressure transducer output is also applied to one input of a differential amplifier (26) having an output that is applied to an analog-to-digital converter (24) having a limited operating range. The other input of the amplifier receives an offset signal from a voltage source (32) to offset the amplified pressure transducer output so that the output of the differential amplifier will not exceed the operating range of the analog-to-digital converter.