Patent ID: 8838215

Claim:
A device for detecting acute cardiac ischemia, the device including: a sensor adapted to sense a cardiac signal from a patient's heart, a memory; and, a digital processor configured to: (i) compute a plurality of patient state values from the cardiac signal and store the plurality of patient state values in the memory, wherein at least two of the plurality of patient state values are different from one another; (ii) compute a plurality of values of a heart signal feature from the cardiac signal, (iii) store each of the plurality values of the heart signal feature so that it is associated with a corresponding patient state value; (iv) analyze the plurality of patient state values to determine whether a change in patient state has occurred such that a prior patient state has changed to a current patient state; (v) operative when a change in patient state has been detected, determine both a measure of the time that has elapsed since the change and a measure of the duration of the prior patient state; (vi) based at least in part on whether a change in patient state has occurred, select a test to detect acute cardiac ischemia, wherein the test is based on the plurality of heart signal feature values, and wherein the test is a threshold test characterized by a threshold that is a function of both the measure of the time that has elapsed since the change and the measure of the duration of the prior patient state.