Electronic blood pressure device

Claim 1

In a blood pressure measuring and recording device: an inflatable cuff, a crystal transducer positioned in the cuff and responsive to blood pressure pulses and cuff pressure to produce a voltage waveform having positive and negative pulses, a gage pressure transducer operably connected to the cuff, a first digital display for systolic blood pressure and a second digital display for diastolic blood pressure, means including an analog to digital converter operably connecting the gage pressure transducer to the two digital displays, means including a first comparator for producing a first signal when the amplitudes of the positive voltage pulses reach a predetermined level, means including an inverter and a second comparator for producing a second signal when the amplitudes of the negative voltage pulses reach a predetermined level, and means responsive to the presence or absence of said first and second signals for determining and recording the patient's blood pressure, said last-named means including a voltage source having two sets of voltage levels, means operably connecting the voltage source with an input of each of the first and second comparators, one set of the voltages being fed into the comparators for determining systolic blood pressure and the other set of voltages being fed into the comparators for determining diastolic blood pressure, and means coacting with the voltage source for shifting from one set of voltages to the other.