A pressure sensor and pressure-sensing catheter in which a deformable pressure sensing membrane is separated from an inner metalized surface on a rigid support by an air gap. An input allows a voltage to be applied to an electrode on the sensing membrane and an output allows reading of the signal modulation from the support surface. An outer sleeve overlays the membrane and a wire bus transmits the signals to a terminal connector. The catheter may include a vented air gap, a multiplexing wire bus, and an internal cable to maintain tension.