Abstract

Apparatus for protecting a pressure sensitive transducer in an extracorporeal blood system and for providing a sterile barrier while the apparatus transmits the blood pressure to the pressure sensitive transducer. The apparatus includes a pressure chamber having a lateral inlet and a lateral outlet, to enable convenient packaging, and having a membrane disposed transverse the chamber and surrounded by the chamber to segregate an inlet side of the chamber from the outlet side of the chamber. The membrane has a generally planar, circular center portion which lies in a plane between the outer peripheral portion of the membrane and the outlet side of the chamber. The membrane has an intermediate portion contiguous with and between the central portion and the outer peripheral portion, with the intermediate portion having a generally U-shaped cross-sectional configuration. The central portion has a substantially greater thickness than the thickness of the intermediate portion, providing a superior displacement of the membrane during operation.