Patent ID: 8708920

Claim:
A method for detecting and responding to apnea in a human subject comprising: measuring in real time the chest impedance signal and heartbeat of a human subject; converting said chest impedance signal per second to a re-sampled chest impedance signal per heartbeat; filtering said re-sampled chest impedance signal to provide a filtered chest impedance signal per heartbeat; renormalizing said filtered chest impedance signal; calculating in real time the running variance of said filtered chest impedance signal; and calculating a probability of apnea from a histogram compiled from the running variance of the filtered chest impedance signal for a set of apneic infants; wherein said histogram is interpreted as a statistical mixture of a first distribution corresponding to apnea events and a second distribution corresponding to regular breathing, and said first distribution divided by the sum of said first distribution and second distribution produces a probability of apnea for each variance; and wherein said filtered chest impedance signal attenuates the impedance caused by the heartbeat.