Detection and analysis of cardiac waveforms

Patent metadata

Field	Value
Publication number	US-10376173-B2
Application number	US-201715498719-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	May 3, 2016
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

An example method includes performing amplitude-based detection to determine location of R-peaks for a plurality of electrograms. The method also includes performing wavelet-based detection to determine location of R-peaks for the plurality of electrograms. The method also includes adjusting the location of the R-peaks determined by the wavelet-based detection of R-peaks based on the location of R-peaks determined by the amplitude-based detection of R-peaks. The method also includes storing, in memory, R-peak location data to specify R-peak locations for the plurality of electrograms based on the adjusting.

First claim

What is claimed is:

1. A method, comprising:
performing, with one or more computer processors, amplitude-based detection to determine locations of amplitude R-peaks for a plurality of electrograms based on exceeding an amplitude cutoff, each of the plurality of electrograms corresponding to a respective input channel;
performing, with the one or more computer processors, wavelet-based detection to determine locations of wavelet R-peaks for the plurality of electrograms;
adjusting, with the one or more computer processors, the locations of wavelet R-peaks, to provide adjusted R-peak locations placed at consistent locations relative to QRS complex morphology for respective electrograms based on the locations of amplitude R-peaks;
storing, in memory communicatively coupled to the one or more computer processors, R-peak location data to specify the adjusted R-peak locations for the plurality of electrograms based on the adjusting; and
driving an output to a display to visualize an output based on the R-peak location data.

2. The method of claim 1 , further comprising computing an R-R interval from the stored R-peak location data.

3. The method of claim 2 , further comprising suggesting one or more beats based on the computed R-R interval relative to suggestion criteria.

4. The method of claim 3 , wherein the suggestion criteria include at least one of default or configurable time values, and
wherein the suggestion criteria includes a threshold that is set to a fractional portion of a specified R-peak to R-peak length, wherein the suggestion criteria is applied to a plurality of computed R-R intervals for at least some of the plurality of electrograms.

5. The method of claim 3 , further comprising generating output data to display a graphical representation of electrical activity for the suggested one or more beats, the graphical representation of electrical activity comprising a portion of the plurality of electrograms for the suggested one or more beats and/or a graphical map derived from the plurality of electrograms for the suggested one or more beats.

6. The method of claim 1 , wherein performing amplitude-based detection further comprises:
reducing baseline drift from the plurality of electrograms to provide baseline-reduced electrograms; and
detecting the R-peak amplitude from the baseline-reduced electrograms.

7. The method of claim 1 , wherein performing amplitude-based detection further comprises:
constructing a histogram of amplitude peak locations from the plurality of electrograms; and
analyzing at least one of the peaks in the histogram to determine the amplitude cutoff.

8. The method of claim 1 , wherein performing wavelet-based detection further comprises:
employing a multi-tree complex wavelet transform to detect the wavelet R-peaks; and
determining the wavelet R-peaks based on the wavelet detections.

9. The method of claim 8 , wherein performing the wavelet-based R-peak detection further comprises using a moving average filter of a predetermined length to distinguish noise from the detected wavelet R-peaks.

10. The method of claim 1 , wherein adjusting locations further comprises:
identifying wavelet-based R-peak detections that do not have corresponding amplitude detections; and
verifying the wavelet-based R-peak detections based on evaluation of a refractory period between peaks and the detected peaks at neighboring nodes.

11. The method of claim 1 , wherein adjusting locations further comprises:
implementing a windowing method by evaluating the detected R-peaks in overlapping regions of successive windowed segments to identify missed R-peaks and remove duplicate detected R-peaks.

12. The method of claim 1 , further comprising:
using the R-peak location data to select a region of interest containing a QRST complex;
performing principal component analysis on the selected region of interest with respect to the plurality of electrograms to define a QRST template;
correlating the QRST template relative to an interval of each of the plurality of electrograms to identify matching regions of interest; and
removing the identified matching regions of interest from each of the plurality of electrograms using interpolation.

13. The method of claim 1 , further comprising measuring a plurality of electrical signals from a plurality of sensors at a plurality of measurement locations to provide the plurality of electrograms, the measurement locations being invasive or non-invasive with respect to a patient's body.

14. A system comprising:
a non-transitory memory to store electrical data representing a plurality of electrograms and machine-readable instructions; and
a processor to access the non-transitory memory and execute the machine-readable instructions, the instructions comprising:
amplitude peak detection code programmed to perform amplitude-based detection to determine locations of amplitude R-peaks for a plurality of electrograms based on amplitude cutoff, each of the plurality of electrograms corresponding to a respective input channel;
wavelet peak detection code programmed to perform wavelet-based detection to determine locations of wavelet R-peaks for the plurality of electrograms;
location adjustment code programmed to adjust locations of wavelet R-peaks to provide adjusted R-peak locations placed at consistent locations relative to QRS complex morphology for respective electrograms based on the locations of amplitude R-peaks; and
code programmed to store in the memory R-peak location data to specify the adjusted R-peak locations for the plurality of electrograms based on the adjusting; and

a display to visualize a graphical representation based on the R-peak location data.

15. The system of claim 14 , further comprising a measurement device comprising a plurality of sensors to measure electrical signals from a plurality of spatial locations across a body surface to provide the plurality of electrograms, the spatial locations being invasive or non-invasive with respect to a patient's body.

16. The system of claim 14 , wherein the instructions further comprise R-R interval calculator code to compute the R-R interval lengths based on the R-peak location data.

17. The system of claim 16 , wherein the R-R interval calculator code is further programmed to suggest one or more beats based on the computed R-R interval relative to suggestion criteria, and
wherein the suggestion criteria includes a threshold that is set to a fractional portion of a specified R-peak to R-peak length, the suggestion criteria being applied to a plurality of computed R-R intervals for at least some of the plurality of electrograms.

18. The system of claim 16 , wherein the graphical representation comprises a visualization of the plurality of electrograms for the suggested one or more beats and/or a graphical map derived from the plurality of electrograms for the suggested one or more beats.

19. The system of claim 14 , wherein the instructions further comprise baseline removal code programmed to reduce baseline drift from the plurality of electrograms to provide baseline-reduced electrograms, wherein the R-peak amplitude is detected from the baseline-reduced electrograms.

20. The system of claim 14 , wherein the amplitude peak detection code further comprises instruction for:
constructing a histogram of amplitude peak locations from the plurality of electrograms; and
analyzing at least one of the peaks in the histogram to determine the amplitude cutoff.

21. The system of c

Assignees

• Cardioinsight Technologies Inc

Inventors

• George Brian P
• Stone Meredith E
• Zeng Qingguo
• Lou Qing
• Edel Connor S
• Jia Ping
• Adair Jeffrey B
• Turovskiy Vladimir A
• Sabo Matthew J
• Bokan Ryan M
• Patel Ketal C
• Ramanathan Charulatha
• Anderson John E
• Hoover Andrew E
• Yao Cheng

Classifications

• A61B5/726

  using Wavelet transforms · CPC title

• A61B5/04085

  Human Necessities · mapped topic

• A61B5/0456 Primary

  Human Necessities · mapped topic

• A61B5/04017

  Human Necessities · mapped topic

• A61B5/7203 Primary

  for noise prevention, reduction or removal · CPC title