Arm simulator for an oscillometric blood pressure monitor

Claim 1

A simulator device for simulating the pressure pulsations from a subject whose blood pressure is being determined by an oscillometric blood pressure monitor with an inflatable pressure cuff, comprising: a. pressure chamber means with an input and an output for creating a pressure pulse at its output related to an applied electrical signal, the input being in pressure communication with the pressure cuff, and the output being in pressure communication with the monitor; b. means for generating the applied electrical signal in the form of a series of pulses occurring at a preselected rate, the amplitudes of said pulses being adjusted in response to the pressure in the pressure cuff to simulate the pressure pulses of a test subject with selected blood pressure values; c. a controllable pressure valve connected between the input and output of the pressure chamber, said valve normally being open; and d. means for closing said valve for a period substantially equal to the period of said pressure pulse, so that the total pressure at the output of the pressure chamber means is the sum of the pressure pulse and the pressure applied from the pressure cuff; e. wherein said pressure chamber means comprises (i) a hollow housing with an input port coupled to the input of said pressure chamber and an output port coupled to the output of said pressure chamber, (ii) a diaphragm dividing the interior of said housing between said input port and said output port, and (iii) means for causing movement of said diaphragm in response to an electrical signal, the amplitude, direction and frequency of the movement being related to the amplitude, polarity and frequency of the electrical signal.