Distinguishing sinus tachycardia from atrial fibrillation and atrial flutter through analysis of atrial channel wavelet transforms

A method for distinguishing two differing heart rhythms comprising the steps of:

• capturing electrical representations of a series of sequential heartbeats;
• transforming these electrical representations into digital data;
• performing mathematical computations including at least a partial discrete wavelet transformation upon the digital data, thereby generating at least a subset of discrete wavelet transformation components corresponding to at least some of the sequential heartbeats chosen such that the components generated and retained include components demonstrated to be suitable for use in distinguishing the two differing heart rhythms and also demonstrated to be relatively low in variability from one heart to another;
• providing a corresponding subset of reference discrete wavelet transformation components that are captured from at least one heart beating in accordance with one of the two differing heart rhythms when the electrical representations of heartbeats that gave rise to these components were captured and computed as described above;
• correlating each subset of transformation components generated from as described in the “performing” step against the subset of transformation components provided from as described in the “providing” step, giving rise to a sequence of correlation values;
• and
• repeatedly mathematically examining a time sequence of the correlation values to give an indication of whether the first or second of the heart rhythms is present, eliminating isolated instances of heartbeat irregularities and focusing upon longer-term trends in the variation of the heart rhythm as indicated by the correlation values.

An implantable defibrillator or other heart monitoring device designed to distinguish two differing heart rhythms comprising:

• electrodes that may be attached to the heart of the recipient of the defibrillator or the patient whose heart is being monitored;
• a first electronic mechanism designed to accept electrical representations of individual heartbeat waveforms from the electrodes, transform these electrical representations into digital data, and then perform plural digital filtering operations each focusing upon varying width and varying-positioned windowed portions of each heartbeat waveform to generate a plurality of components, one from each such digital filtering operation, each such component representative of different features of each heartbeat waveform some of which features are spread over the entire width of the waveform and other of which features are concentrated in the varying-width and varying-positioned windowed portions of each waveform, selecting the filtering operations such that the components generated and retained are components determined to be suitable for use in distinguishing the two differing heart rhythms and also determined to be relatively low in the variability of their differing heart rhythm distinguishing capabilities from one recipient or patient to another;
• a template containing at least a corresponding subset of components generated as described above from heartbeat waveforms captured from at least one individual whose heart was beating in accordance with one of the two differing heart rhythms when the electrical representations of heartbeats that gave rise to these template components were captured;
• a second electronic mechanism for correlating the subset of components provided by the first mechanism against the subset of components provided by the template, giving rise to a correlation value;
• and
• a third electronic mechanism for mathematically examining a time series of the correlation values received from the second mechanism and for giving an indication of whether the first or second of the heart rhythm is present, eliminating isolated instances of heartbeat irregularities and focusing upon longer-term trends in the variation of the heart rhythm.