Patent ID: 8798761

Claim:
A system for monitoring the acoustic coupling of an acoustic transducer attached to a patient's body, comprising: an acoustic transducer attachable to the body and in acoustic communication with an implantable medical device; a signal generator coupled to the acoustic transducer, the signal generator adapted to supply a time-varying electrical signal to the acoustic transducer for generating an acoustic wave; a circuit configured to measure at least one electrical parameter of the acoustic transducer in response to the electrical signal while the transducer is acoustically loaded to a tissue interface of the body, the at least one electrical parameter including a frequency parameter associated with a frequency-dependent response of the acoustic transducer to the time-varying electrical signal; and an evaluation module adapted to evaluate the degree of acoustic coupling of the loaded transducer to the tissue interface by evaluating a complex impedance curve associated with the loaded transducer based at least in part on the measured frequency parameter, wherein the evaluation module is configured to evaluate the degree of acoustic coupling by causing the signal generator to sweep the electrical signal across a frequency range and measure a corresponding impedance parameter at each of a plurality of frequencies in the frequency range, wherein the evaluation module is further configured to analyze a width of the complex impedance curve.