Determining onsets and offsets of cardiac depolarization and repolarization waves

A system of cardiac pacing comprising:

• a) processing means for determining a baseline rhythm using a plurality of body-surface electrodes, the baseline rhythm includes an atrial marker and a ventricular marker;
• b) processing means for defining a pre-specified window between the atrial marker and the ventricular marker;
• c) processing means for applying a low pass filter to a signal within the window;
• d) processing means for determining a rectified slope of the signal;
• e) processing means for determining a time point (t1) in which the rectified slope exceeds 10% of a maximum value of the rectified slope;
• and
• f) processing means for determining a point of onset of a depolarization complex in the signal, wherein the point of onset occurs at a largest curvature in the signal within the window from Vs-100 ms to t1.

A non-transitory, computer-readable storage medium comprising instructions that, when executed, cause a processor to perform a method for comprising:

• a) determining a baseline rhythm using a plurality of body-surface electrodes, the baseline rhythm includes an atrial marker and a ventricular marker;
• b) defining a pre-specified window between the atrial marker and the ventricular marker;
• c) applying a low pass filter to a signal within the window;
• d) determining a rectified slope of the signal;
• e) determining a time point (t1) in which the rectified slope exceeds 10% of a maximum value of the rectified slope;
• and
• f) determining a point of onset of a depolarization complex in the signal, wherein the point of onset occurs at a largest curvature in the signal within the window from Vs-100 ms to t1.

A computer-implemented method of cardiac pacing comprising:

• a) determining a baseline rhythm using a plurality of body-surface electrodes, the baseline rhythm includes an atrial marker and a ventricular marker;
• b) defining a pre-specified window between the atrial marker and the ventricular marker;
• c) applying a low pass filter to a signal within the window;
• d) determining a rectified slope of the signal;
• e) determining a time point (t1) in which the rectified slope exceeds 10% of a maximum value of the rectified slope;
• and
• f) determining a point of onset of a depolarization complex in the signal, wherein the point of onset occurs at a maximum curvature in the signal within the window from Vs-100 ms to t1, wherein the maximum curvature being selected from radii determined from r=|y″|/(1+|y′|2)(3/2) in which y″ and y′ are the double and single derivatives of y=f(t), respectively.

A computer-implemented method of cardiac pacing comprising:

• a) determining a baseline rhythm using a plurality of body-surface electrodes, the baseline rhythm includes an atrial marker and a ventricular marker;
• b) defining a pre-specified window between the atrial marker and the ventricular marker;
• c) applying a low pass filter to a signal within the window;
• d) determining a rectified slope of the signal;
• e) determining a time point (t1) in which the rectified slope exceeds 10% of a maximum value of the rectified slope;
• and
• f) determining a point of onset of a depolarization complex in the signal, wherein the point of onset occurs at a maximum curvature in the signal within the window from Vs-100 ms to t1, wherein the maximum curvature being selected from radii determined from r≈|y″|/(1+|y′|2) in which y″ and y′ are the double and single derivatives of y=f(t), respectively.