Abstract: A hinge clamp mechanism and sensor for performing pulse oximetry tests, as well as for performing other diagnostic procedures that can be conducted on a human body part, such as a finger. More particularly, the hinge clamp mechanism utilizes one or more slots, pins and springs to enclose the body part being tested. The hinge clamp relies on a movable pivot point connecting upper and lower portions of the device and the biasing force of one or more cantilevered leaf springs to enable the upper and lower body portions of the device to conform to the upper and lower surfaces of the body part, and to evenly distribute the gripping pressure of the device over the upper and lower surfaces of the body part.