Method and apparatus for quantifying beat-to-beat variability in physiologic waveforms
AssigneeMassachusetts Institute of Technology
InventorsDaniel T. Kaplan, Richard J. Cohen
Life of this patent
Estimating the term…
Abstract
Myocardial electrical stability is assessed by sampling an ECG waveform at corresponding fiducial locations for a plurality of beats and creating a scatter plot of the i.sup.th sample versus the (i- 1)th sample. A parameter .lambda. is determined which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)= 4.lambda.x(i- 1)[ 1-x(i- 1)]. The value of the parameter .lambda. is related to the electrical stability of the heart.
Claims19
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising:
- sampling the waveform at corresponding fiducial locations for a plurality of cycles;
- creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- determining a parameter .lambda. which optimizes the fit of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of .lambda. quantifying the degree of alternation.
Method for assessing susceptibility to ventricular fibrillation comprising:
- sampling an ECG waveform at corresponding fiducial locations for a plurality of beats;
- creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- determining a parameter .lambda. which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of the parameter .lambda. being related to the susceptibility of fibrillation.
Apparatus for determining cycle-to-cycle alternation in a physiologic waveform comprising:
- means for sampling the waveform at corresponding fiducial locations for a plurality of cycles;
- means for creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- computing means for determining a parameter .lambda. which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of .lambda. quantifying the degree of alternation.
Apparatus for assessing susceptibility to ventricular fibrillation comprising:
- means for sampling an ECG waveform at corresponding fiducial locations for a plurality of beats;
- means for creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- computing means for determining a parameter .lambda. which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of the parameter .lambda. being related to the susceptability to fibrillation.
Method for assessing susceptibility to ventricular fibrillation comprising:
- sampling a physiologic waveform at corresponding fiducial locations for a plurality of cycles;
- creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- determining a parameter .lambda. which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of the parameter .lambda. being related to the susceptibility to fibrillation.
Apparatus for assessing susceptibility to ventricular fibrillation comprising:
- means for sampling a physiologic waveform at corresponding fiducual locations for a plurality of beats;
- means for creating a scatter plot of the ith sample versus the (i-1)th sample;
- and
- computing means for determining a parameter .lambda. which minimizes the sum of total distances of the points of the scatter plot to an equation x(i)=4.lambda.x(i-1)[1-x(i-1)], the value of the parameter .lambda. being related to the susceptibility to fibrillation.
Method for determining cycle-to-cycle alternation in a physiologic waveform comprising:
- sampling the waveform at corresponding fiducial locations for a plurality of cycles;
- storing ordered pairs for the ith and (i-1)th samples;
- and
- determining a parameter .lambda. which minimizes the sum of the total distances of the points represented by the ordered pairs to an equation x(i)=4.lambda.x(-1)[1-x(i-1)], the value of .lambda. quantifying the degree of alternation.
Dependencies are inferred from the claim text.