Patent ID: 9579065
Date: 2017-02-28
CPC Classifications: A61B,A61N

Claim:
1. An implantable cardiac device comprising: a plurality of electrodes configured for sensing electrical signals; and operational circuitry configured for analyzing signals received from the sensing electrodes, wherein the operational circuitry and electrodes are configured to define at least two sensing vectors for sensing cardiac signals and the operational circuitry is configured to perform the following: for a first sensing vector, calculating each of: combining the signal to noise ratio, cardiac signal amplitude and measure of biphasic or monophasic nature of sensed signals to generate a sensing quality metric for the first sensing vector; wherein: the operational circuitry is further configured to sense a plurality of cardiac cycles with selected electrodes for the first vector by applying a detection profile to a sensed cardiac signal to detect a cardiac cycle, wherein the detection profile includes a refractory period and a sensing period, the refractory period being applied to a first portion of the cardiac cycle and the sensing period being applied to at least a second portion of the cardiac cycle; and the operational circuitry is configured to calculate a measure of biphasic or monophasic nature of cardiac cycles by comparing an average sensed positive amplitude from the first portion of two or more of the cardiac cycles to an average sensed negative amplitude from the first portion of two or more of the cardiac cycles.