Medical devices for mapping cardiac tissue

Patent metadata

Field	Value
Publication number	US-2016007932-A1
Application number	US-201514705395-A
Country	US
Kind code	A1
Filing date	May 6, 2015
Priority date	May 9, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

Medical devices and methods for making and using medical devices are disclosed. An example method may include a method of mapping the electrical activity of a heart. The method may include sensing a plurality of signals with a plurality of electrodes positioned within the heart, determining a dominant frequency of the plurality of signals and generating an alternate signal for each of the plurality of signals corresponding to the dominant frequency. The alternate signals may have a phase-shift corresponding to one of the plurality of signals. The method may also include displaying a characteristic of the alternate signal over time.

First claim

What is claimed is:

1 . A method of mapping electrical activity of a heart, the method comprising:
sensing a plurality of signals with a plurality of electrodes positioned within the heart; determining a dominant frequency of the plurality of signals; generating an alternate signal for each of the plurality of signals corresponding to the dominant frequency, wherein each of the alternate signals has a phase-shift corresponding to one of the plurality of signals; and displaying a characteristic of the alternate signal over time.

2 . The method of claim 1 , wherein determining a dominant frequency comprises:
processing each of the plurality of signals using a Fourier Transform; generating a composite signal based on the processed plurality of signals; identifying the frequency with the maximum power in the composite signal.

3 . The method of claim 2 , further comprising band-pass filtering each of the processed plurality of signals.

4 . The method of claim 3 , wherein the band-pass filtering comprises passing data in the 3 to 7 Hz band for each of the processed plurality of signals.

5 . The method of claim 2 , wherein generating a composite signal based on the processed plurality of signals comprises:
generating a composite signal with a value at each frequency that is one of a median value, a mean value, or a mode value of the processed plurality of signals at each frequency.

6 . The method of claim 5 , wherein the phase-shift of the alternate signal is based on the composite signal.

7 . The method of claim 6 , wherein each alternate signal is a sinusoid.

8 . The method of claim 7 , wherein each alternate signal is an analytic representation of a sinusoid.

9 . The method of claim 8 , wherein the analytic representation is generated by a Hilbert transform.

10 . The method of claim 7 , wherein the analytic representation is a sawtooth.

11 . The method of claim 7 , further comprising determining a fiducial point on each alternate signal, and wherein the fiducial point on each alternate signal is one of the following:
a point with a maximum negative derivative; a point of zero-crossing; and a point at phase π/2.

12 . The method of claim 11 , further comprising determining an activation time for each of the plurality of signals based on the identified fiducial points, generating an activation map based on the determined activation times for each of the plurality of signals, and displaying the activation map.

13 . A method for determining activation times in cardiac electrical signals, the method comprising:
sensing a plurality of cardiac electrical signals with a plurality of electrodes positioned within the heart; processing the plurality of signals, wherein the processing comprises transforming the plurality of signals into the frequency domain; generating a composite signal from the processed plurality of signals; identifying the largest frequency component from the composite signal; generating an approximation signal for each of the plurality of signals, wherein each generated approximation signal has a phase-shift; and displaying a characteristic of the approximation signal over time.

14 . The method of claim 13 , wherein processing the plurality of signals further comprises removing data outside of the 3 to 7 Hz band in each of the plurality of signals.

15 . The method of any one of claims 13 , wherein generating the composite signal from the processed plurality of signals comprises:
determining the median value of all of the plurality of signals at each frequency; determining the mean value of all of the plurality of signals at each frequency; or determining the mode value of all of the plurality of signals at each frequency.

16 . The method of any one of claims 15 , further comprising determining a fiducial point on each approximation signal, determining an activation time for each of the plurality of signals based on the identified fiducial points, generating an activation map based on the determined activation times for each of the plurality of signals, and displaying the activation map.

17 . A system for mapping the electrical activity of the heart, the system comprising:
a catheter shaft; a plurality of electrodes coupled to the catheter shaft; and a processor coupled to the catheter shaft, wherein the processor is configured to:
collect a plurality of signals sensed by the plurality of electrodes;
determine a dominant frequency of the plurality of signals;
generate an alternate signal for each of the plurality of signals corresponding to the dominant frequency, wherein each of the alternate signals has a phase-shift corresponding to one of the plurality of signals;
displaying a characteristic of the alternate signals over time.

18 . The system of claim 17 , wherein to determine a dominant frequency of the plurality of signals, the processor is further configured to:
transform each of the plurality of signals into the frequency domain; generate a composite signal from each of the transformed plurality of signals; and determine the frequency that has the maximum power in the composite signal.

19 . The system of claim 18 , wherein each alternate signal is a sinusoid or a sawtooth.

20 . The system of claim 18 , wherein each alternate signal is an analytic representation of a sinusoid.

Assignees

• Boston Scient Scimed Inc

Inventors

• Laughner Jacob I
• Shome Shibaji
• Thakur Pramodsingh Hirasingh
• Meyer Scott A

Classifications

• A61B5/7253

  characterised by using transforms · CPC title

• A61B5/7278

  Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals · CPC title

• A61B5/7257 Primary

  using Fourier transforms · CPC title

• A61B18/1492

  having a flexible, catheter-like structure, e.g. for heart ablation (A61B18/1477 takes precedence) · CPC title

• A61B5/725

  using specific filters therefor, e.g. Kalman or adaptive filters (specific diagnostics methods using using bioelectric or biomagnetic signals A61B5/316) · CPC title