An embodiment of the invention provides, among other things, a method for providing a cost modification of a health care item for a subject. Preferably, the method is used to treat or prevent tissue damage to a human heart. Communication with a compliance node is established. The whip stitched graft construct is provided with at least two regions, one region formed of at least a plurality of tendon strand regions tied and whip stitched together, and the other region formed of untied segments of the plurality of tendon strands. Similarly, the second connector can enable the two-way transfer of digital data between the external device and the portable storage device. Depending on whether the signal of the lambda sensor is stable, a lambda value for the at least one injection valve is measured using the lambda sensor at the set operating condition.