Purpose. The difficulty of recording service history of rehabilitation devices makes it impractical for prescribing centres to monitor treatment effectively, or implement maintenance and replacement policies that permit safety and economic viability to be fully complementary. An approach to providing such a facility has been investigated, so that specified treatment can be monitored or device replacement matched to the functional activity of the patient. Methods. A two-channel data logger has been developed that can record, over periods in excess of 12 months, information in an event-monitoring channel; and in the second channel a varying analogue signal at the time an event occurs. In addition a downloading interface allows data to be transferred and then processed in a personal computer during a routine patient visit. Results. Laboratory testing demonstrated that the system recorded events accurately. Field trials verified a battery life exceeding 12 months for continuous routine monitoring of twice daily orthosis application in the event logging channel. The analogue channel was tested by applying known signals to the logger at the time events were monitored, and comparing the output to the input signal. Outcome. The feasibility of routinely monitoring the use of rehabilitation devices was successfully demonstrated and production development is now being undertaken.