Abstract: A probe for measuring circumferential pressures inside a body cavity. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors (15) which typically comprise support tube sections (55) with flexible side wall areas (57, 16). These are arranged along the length of the probe in two areas, one just proximal to the tip (13) for the sensing of fluid pressure inside the bladder, and five in a sensing section (14) which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections (10) interspersed with flexible support tube sections in the form of bellows (58) to provide flexibility.