Abstract: A system that provides the ability to integrate both diagnostic tissue detection and therapeutic tissue treatment functionality in an implantable medical device (IMD), such as a graft or stent. The system comprises: an IMD having a pair of electrodes configured to contact biological tissue at an implant location; an impedance sensor configured to detect data indicative of a complex impedance of the biological tissue at the electrodes for a plurality of frequencies; and an analysis device configured to determine one or more cell types in the biological tissue using information indicative of variation in phase and magnitude of the complex impedance across the plurality of frequencies. The system may include a signal generator for applying a treatment signal to the same electrodes.