Biomedical force measuring apparatus

A force transducer usable tokodynamometer for measuring intrauterine pressure and motion, and for measuring other force exerted by human body or other organisms. The tokodynamometer has a cavity filled with an incompressible fluid and closed by a flexible diaphragm disposed for contacting the body portion being studied. A zero-displacement fluid-pressure transducer is in the cavity and provides an electrical signal responsive to pressure in the fluid, as body force acts through the flexible diaphragm to induce pressure in the fluid. Changes in intrauterine pressure or other body forces are thus measured with no significant physical displacement of a transducer or other force-measuring element. The fluid-filled cavity has the shape of a truncated cone with the diaphragm at the larger end and the transducer at the smaller end, increasing the sensitivity of the transducer.