Patent ID: 8121687

Claim:
A method for evaluating movement of a cardiac tissue location in a subject, the method comprising: (a) determining timing of a signal obtained from a resistive strain gauge of an implantable device stably associated with the cardiac tissue location, wherein the implantable device comprises: a lead of a length with a proximal end and a distal end, the lead comprising: a guide wire core formed within the lead along the length of the lead, wherein the resistive strain gauge is physically attached to the guide wire core; and at least one insulated conductor spirally wrapping the guide wire core from the proximal end to the distal end, wherein the resistive strain gauge is electrically coupled to an insulated conductor of the at least one insulated conductor; and (b) evaluating movement of the cardiac tissue location via a signal processing element communicatively coupled to the implantable device based on the timing of the signal obtained from the resistive strain gauge.