Channel integrity detection and reconstruction of electrophysiological signals

Patent metadata

Field	Value
Publication number	US-10874318-B2
Application number	US-201815913262-A
Country	US
Kind code	B2
Filing date	Mar 6, 2018
Priority date	Mar 6, 2018
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

This disclosure relates to integrated channel integrity detection and to reconstruction of electrophysiological signals. An example system includes a plurality of input channels configured to receive respective electrical signals from a set of electrodes. An amplifier stage includes a plurality of differential amplifiers, each of the differential amplifiers being configured to provide an amplifier output signal based on a difference between a respective pair of the electrical signals. Channel detection logic is configured to provide channel data indicating an acceptability of each of the plurality of input channels based on an analysis of a common mode rejection of the amplifier output signals.

First claim

What is claimed is:

1. A system comprising:
a plurality of input channels configured to receive respective electrical signals from a set of electrodes;
an amplifier stage that includes a plurality of differential amplifiers, each of the differential amplifiers being configured to provide an amplifier output signal based on a difference between a respective pair of the electrical signals; and
channel detection logic configured to convert the amplifier output signal of each of the plurality of differential amplifiers to frequency domain data having an amplitude value representing a level of common mode rejection at different frequencies, and apply a threshold to the frequency domain data at a predetermined frequency, corresponding to a common mode signal of each of the plurality of differential amplifiers, to provide channel data indicating an acceptability of each of the plurality of input channels.

2. The system of claim 1 , further comprising an anti-aliasing filter coupled between each input channel and an input of its respective differential amplifier, each filter configured to provide filtered signals having a frequency below a frequency threshold as the common mode signal to the input of the respective differential amplifiers for each input channel.

3. The system of claim 2 , wherein the filtered signals provided to the inputs of the differential amplifiers include power line interference signals corresponding to the common mode signal of each differential amplifier.

4. The system of claim 1 , further comprising the set of electrodes, wherein the set of electrodes includes a reference electrode and a plurality of other electrodes, each respective pair of the electrical signals includes a signal from the reference electrode and one of the plurality of other electrodes.

5. The system of claim 4 , wherein each of the plurality of differential amplifiers includes a first input coupled to receive a reference signal from the reference electrode and a second input coupled to receive the electrical signal from one of the plurality of other electrodes, the amplifier output signal of each of the plurality of differential amplifiers providing an indication of a common mode rejection between the reference electrode and each respective other electrode.

6. The system of claim 5 , further comprising a processing unit and memory, the processing unit executes instructions stored in the memory, the instructions including the channel detection logic, wherein the channel data indicating the acceptability for each of the plurality of input channels is stored in the memory, and
wherein the channel detection logic further comprises:
a fast Fourier transform programmed to convert the amplifier output signal of each of the plurality of differential amplifiers to the frequency domain data; and
a frequency analyzer programmed to apply the threshold to the frequency domain data to determine the acceptability for each of the plurality of input channels.

7. The system of claim 6 , wherein the set of electrodes and corresponding input channels are arranged in a plurality of spatial zones, wherein the channel detection logic calculates the threshold that the frequency analyzer is to apply for each of the plurality of spatial zones.

8. The system of claim 6 , further comprising a low-pass filter coupled between each input channel and an input of a respective differential amplifier, each filter configured to provide a low-pass filtered signal that includes power line interference signals.

9. The system of claim 6 , wherein the instructions further comprise:
a reconstruction engine programmed to reconstruct electrical signals on a cardiac envelope based on the electrical signals from the set of electrodes and geometry data representing spatial geometry of the set of electrodes; and
an output generator programmed to generate a visualization representing the reconstructed electrical signals on the cardiac envelope.

10. The system of claim 9 , wherein the reconstruction engine further comprises:
a matrix calculator programmed to compute a transformation matrix based on at least one boundary condition and geometry data associated with the electrodes;
a matrix adjustment method programmed to modify the transformation matrix based on the acceptability of each of the plurality of input channels to provide a modified transformation matrix; and
a regularization method programmed to estimate the reconstructed electrical signals on the cardiac envelope based on the modified transformation matrix and the electrical signals from the set of electrodes.

11. The system of claim 10 , wherein the reconstruction engine implements a method of fundamental solution to compute the reconstructed electrical signals on the cardiac envelope,
wherein the transformation matrix includes a first boundary condition that parameterizes signal channel information for the set of electrodes and a second boundary condition that parameterizes the spatial geometry of the set of electrodes, and
wherein the matrix adjustment method removes the signal channel information from the first boundary condition for each bad channel that is identified in the acceptability of each of the plurality of input channels while retaining the spatial geometry for each electrode in the set of electrodes regardless of the acceptability of each of the plurality of input channels indicated by the channel data.

12. The system of claim 10 , wherein the reconstruction engine implements a boundary element method to compute the reconstructed electrical signals on the cardiac envelope, and
wherein the matrix adjustment method converts channel signal information in the transformation matrix for each bad channel, which is identified in the channel data of each of the plurality of input channels, to unknown variables for the regularization method to solve as part of the estimation of reconstructed electrical signals on the cardiac envelope.

13. A method, comprising:
receiving, via a plurality of input channels, respective input electrical signals sensed by a set of electrodes;
amplifying, via a plurality of differential amplifiers, a difference between respective pairs of the input electrical signals and providing an amplified output signal corresponding to the difference;
converting the amplified output signal from each of the plurality of differential amplifiers to frequency domain data having an amplitude representing signal components at different frequencies;
applying a threshold to the frequency domain data at a predetermined frequency corresponding to a common mode signal of each of the plurality of differential amplifiers; and
generating channel data to specify an acceptability or unacceptability for each of the plurality of input channels based on the application of the threshold to the frequency domain data.

14. The method of claim 13 , further comprising filtering the input electrical signals to provide corresponding filtered signals to inputs of each respective differential amplifier.

15. The method of claim 14 , wherein the filtered signals include power line interference signals as a common mode signal.

16. The method of claim 15 , wherein the respective input electrical signals include a reference signal and a plurality of other electrical signals, and
wherein each of the plurality of differential amplifiers receive the reference signal at one input thereof and one of the plurality of other electrical signals at another input thereof, each of the plurality of differential amplifiers providing the amplified output signal to indicate a common mode rejection between the

Assignees

• Cardioinsight Technologies Inc

Inventors

• Shahdoostfard Shahabedin
• Zeng Qingguo
• Jia Ping
• George Brian P
• Ponziani Kevin
• Lou Qing
• Varghai Daniel
• Adair Jeffrey B

Classifications

• A61B5/367

  Electrophysiological study [EPS], e.g. electrical activation mapping or electro-anatomical mapping · CPC title

• A61B5/307

  specially adapted for particular uses · CPC title

• A61B5/339

  Displays specially adapted therefor · CPC title

• A61B5/305

  Common mode rejection · CPC title

• A61B5/7257

  using Fourier transforms · CPC title