Wireless recording system for long-term monitoring of bone fracture healing

Abstract

Monitoring of bone fracture healing is a relevant topic of research. Current diagnostics are often based on complex imaging techniques. These cannot be used for onlinerecording, which is necessary to observe the patient during physiotherapy and daily routine in order to intervene in the case of overload. Monitoring of fracture healing was done before by our group using instrumented multidirectional locking screw implants. Strain-sensitive transponders were applied on the surface of the implant and data transmission was achieved by using the passive radio frequency identification (RFID) technology. Monitoring of the healing process was possible during hospitalization only. This was mainly due to the energy consumption of the recording system required for readout of the passive RFID sensor transponder. This paper presents a new energy-efficient RFID reader topology, especially designed for the mobile recording of patient data. © 2009 Springer-Verlag.