Calculation of self-correlation in an implantable cardiac device

摘要

Self-correlation enhancements and implementations are described. In particular, certain examples demonstrate the analytical tools to reduce the computational burden of generating a self-correlation function within an implantable medical device. Peak selector and tracking analysis are also included as secondary elements for identifying and generating confidence in rate estimates based on the self-correlation function. The approach may enable an alternative calculation of cardiac rate in an implantable medical device as a stand-alone rate detector or as a double-check of other rate calculations.

主权项

1. A method of iterative analysis of cardiac signals comprising:
sensing cardiac signals from a plurality of electrodes; generating a self-correlation function from the sensed cardiac signals, the self-correlation function having amplitudes as a function of lag depth; and determining a first estimate of cardiac rate using the self-correlation function; wherein the step of generating the self-correlation function includes: selecting a first data set from the cardiac signal having a first length, N, and a second data set from the cardiac signal having a second length approximately twice the length of the first length, wherein the second data set includes the first data set; repeatedly subtracting the first data set from the second data set at a series of lag depths from approximately zero to approximately N, to generate the self-correlation function.