Pressure transducer

Claim 1

A disposable blood pressure transducer useful in connection with the measurement of fluid pressure in an extracorporal dynamic liquid handling system, said transducer comprising: a housing defining a pressure chamber, said housing including a pair of liquid connections communicating with the chamber for directing a continual flow of liquid into and out of the chamber and means defining a pressure transmission port communicating with said chamber; a generally planar flexible diaphragm disposed across said port in liquid and pressure sealing relationship thereto, all portions of the housing and diaphragm in contact with said liquid being constructed of a synthetic plastic material; a closure member engaging said diaphragm on the opposite side thereof from the chamber for maintaining the diaphragm in said fluid and pressure sealing relationship, said member defining a cavity opening toward the diaphragm and having an aperture opening away from the diaphragm; and a pressure transfer element having a portion thereof disposed within said cavity proximal the diaphragm and an elongated projection extending away from the diaphragm and through the aperture, said pressure transfer element being loosely mounted in the cavity for at least limited completely free movement toward and away from the diaphragm relative to the latter and to the closure member, said pressure chamber and said fluid connections presenting a substantially unimpeded path for flow of liquid therethrough in either direction across the diaphragm.