Patent Document ID: 9014807
Application ID: 13297785

Base Claim:
1. An apparatus, comprising: an implantable medical device, comprising: a therapy circuit coupled to a therapy delivery terminal, the therapy circuit configured to generate a specified electrostimulation therapy for delivery to a tissue site via the therapy delivery terminal; a measurement circuit comprising: an excitation circuit, configured to generate multiple instances of a non-therapeutic, non-tissue-stimulating voltage or current excitation using a first terminal combination including the therapy delivery terminal, within the duration of a cardiac cycle; and a detector circuit, configured to receive corresponding voltages or currents developed at the first terminal combination in response to the multiple instances of excitation, within the duration of the cardiac cycle; and a processor circuit coupled to the measurement circuit and configured to determine at least two impedances using information about the instances of excitation, and information provided by the measurement circuit about the received voltages or currents, the two impedances corresponding to at least two instances of excitation separated enough in time to capture an impedance artifact indicative of a status of an electrostimulation therapy lead, the impedance artifact elicited at least in part by a motion of the heart; wherein the processor circuit is configured to determine the electrostimulation therapy lead status at least in part using the at least two impedances.

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Claim 4:
4. The apparatus of claim 1 , wherein the excitation circuit is configured to generate a voltage excitation across the first terminal combination; and wherein the detector circuit is configured to receive a current developed at the first terminal combination in response to the voltage excitation.