An ultraviolet illuminator for providing a cleaning treatment to a medical device is disclosed. The ultraviolet illuminator can include an ultraviolet cleaning treatment system that operates in conjunction with at least one ultraviolet radiation source and sensor to clean surfaces of a medical device for purposes of disinfection, sterilization, and/or sanitization. The ultraviolet illuminator is suitable for a wide variety of medical devices, instruments and equipment. Stethoscopes and medical instrument probes are illustrative examples of some devices that can be used with the ultraviolet illuminator.