A system and device for measuring sexual function includes an adjustable ring forming an opening to receive a penis, at least one diagnostic sensor positioned on an inner surface of the adjustable ring, wherein the ring automatically couples the diagnostic sensor to the penis throughout a range of ring diameters, and a microcontroller in communication with the at least one diagnostic sensor. The at least one diagnostic sensor measures data during sexual activity and communicates the data to the microcontroller. In fact, in an example, the device is configured to be worn by a user during sexual activity.
