Medical device and method for detecting electrical signal noise

Patent metadata

Field	Value
Publication number	US-2025345003-A1
Application number	US-202519277220-A
Country	US
Kind code	A1
Filing date	Jul 22, 2025
Priority date	May 15, 2020
Publication date	Nov 13, 2025
Grant date	—

Abstract

A medical device is configured to sense event signals from a cardiac electrical signal and determine maximum amplitudes of cardiac electrical signal segments associated with sensed event signals. The medical device is configured to determine at least one tachyarrhythmia metric based on at least a greatest one of the determined maximum amplitudes. The medical device may determine when the at least one tachyarrhythmia metric does not meet true tachyarrhythmia evidence and, in response, determine when the maximum amplitudes meet suspected noise criteria. The medical device may withhold a tachyarrhythmia detection and tachyarrhythmia therapy when suspected noise criteria are met.

First claim

What is claimed is:

1 . A medical device comprising:
a sensing circuit configured to:
sense one or more cardiac electrical signals; and
sense event signals from the one or more cardiac electrical signals;
a control circuit configured to:
determine if suspected noise criteria are met for at least a threshold number of a plurality of groups of the event signals, where each of the plurality of groups of the event signals comprises up to a predetermined number of the event signals;
determine that the sensed event signals meet a tachyarrhythmia detection threshold; and
a therapy delivery circuit configured to:
deliver a tachyarrhythmia therapy in response to the tachyarrhythmia detection threshold being met and the suspected noise criteria not being met for at least the threshold number of the plurality of groups of the event signals; or
withhold delivering the tachyarrhythmia therapy in response to the suspected noise criteria being met for at least the threshold number of the plurality of groups of the event signals.

2 . The medical device of claim 1 wherein the control circuit is further configured to determine if the suspected noise criteria are met by at least:
determining a peak amplitude from a first cardiac electrical signal of the one or more cardiac electrical signals for each event signal sensed by the sensing circuit in each of the plurality of groups of the event signals;
determine if the peak amplitudes of a respective group of the plurality of groups of the event signals meet the suspected noise criteria.

3 . The medical device of claim 2 wherein the sensing circuit is further configured to:
sense a second cardiac electrical signal of the one or more cardiac electrical signals different than the first cardiac electrical signal; and
sense the event signals from the second cardiac electrical signal.

4 . The medical device of claim 2 wherein the control circuit is further configured to determine each of the peak amplitudes by determining a peak to peak amplitude of a time segment of the first cardiac electrical that is centered on a respective sensed event signal.

5 . The medical device of claim 1 wherein the control circuit is further configured to:
determine one or more suspected true event intervals in a group of the plurality of groups of event signals;
determine that the one or more suspected true event intervals do not fall in a specified interval range; and
in response to the one or more suspected true event intervals not falling in the specified interval range, determine if the group of the plurality of groups of event signals meets the suspected noise criteria.

6 . The medical device of claim 1 wherein the control circuit is further configured to determine that the sensed event signals meet the tachyarrhythmia detection threshold by:
determining sensed event intervals from the event signals;
determining a count of the sensed event intervals that meet one or more tachyarrhythmia detection intervals; and
determining that the count meets the tachyarrhythmia detection threshold.

7 . The medical device of claim 6 wherein the control circuit is further configured to:
determine when the count of the sensed event intervals that meet one or more tachyarrhythmia detection intervals meets a confirmation threshold that is less than the tachyarrhythmia detection threshold; and
determine if a first group of the plurality of groups of the event signals meet the suspected noise criteria in response to the count meeting the confirmation threshold.

8 . The medical device of claim 7 wherein the control circuit is further configured to:
in response to the count meeting the confirmation threshold, determine peak-to-peak amplitudes from a first cardiac electrical signal of the one or more cardiac electrical signals for each event signal of the first group of the plurality of groups; and
determine if the first group of the plurality of groups of the event signals meets the suspected noise criteria based on the peak-to-peak amplitudes.

9 . The medical device of claim 1 wherein the control circuit is further configured to determine if the suspected noise criteria are met for at least the threshold number of the plurality of groups of the event signals wherein the plurality of groups of the event signals comprise overlapping groups of the predetermined number of event signals.

10 . The medical device of claim 1 further comprising:
a memory configured to store peak amplitudes for at least the predetermined number of event signals;
wherein the control circuit is further configured to:
for each of up to the predetermined number of the event signals of a respective group of the plurality of groups of the event signals, determine a peak to peak amplitude from the one or more cardiac signals;
buffer the peak to peak amplitudes determined for the predetermined number of the event signals in the memory; and
determine that the suspected noise criteria are met for the respective group of the plurality of groups of the event signals based on at least the buffered peak to peak amplitudes.

11 . A method comprising:
sensing one or more cardiac electrical signals; sensing event signals from the one or more cardiac electrical signals; determining if suspected noise criteria are met for at least a threshold number of a plurality of groups of the event signals, where each of the plurality of groups of the event signals comprises up to a predetermined number of the event signals; determining that the sensed event signals meet a tachyarrhythmia detection threshold; and one of:
delivering a tachyarrhythmia therapy in response to the tachyarrhythmia detection threshold being met and the suspected noise criteria not being met for at least the threshold number of the plurality of groups of the event signals; or
withholding delivering the tachyarrhythmia therapy in response to the suspected noise criteria being met for at least the threshold number of the plurality of groups of the event signals.

12 . The method of claim 11 wherein determining if the suspected noise criteria are comprises at least:
determining a peak amplitude from a first cardiac electrical signal of the one or more cardiac electrical signals for each event signal sensed by the sensing circuit in each of the plurality of groups of the event signals;
determine if the peak amplitudes of a respective group of the plurality of groups of the event signals meet the suspected noise criteria.

13 . The method of claim 12 further comprising:
sensing a second cardiac electrical signal of the one or more cardiac electrical signals different than the first cardiac electrical signal; and
sensing the event signals from the second cardiac electrical signal.

14 . The method of claim 12 further comprising determining each of the peak amplitudes by determining a peak to peak amplitude of a time segment of the first cardiac electrical that is centered on a respective sensed event signal.

15 . The method of claim 11 further comprising:
determining one or more suspected true event intervals in a group of the plurality of groups of event signals;
determining that the one or more suspected true event intervals do not fall in a specified interval range; and
in response to the one or more suspected true event intervals not falling in the specified interval range, determining if the group of the plurality of groups of event signals meets the suspected noise criteria.

16 . The method of claim 11 wherein determining that the sensed event signals meet the tachyarrhythmia detecti

Assignees

• Medtronic Inc

Inventors

• Greenhut Saul E
• Liu Yuanzhen
• Zhang Xusheng

Classifications

• A61B5/33

  specially adapted for cooperation with other devices · CPC title

• A61B5/346

  Analysis of electrocardiograms · CPC title

• A61N1/365

  controlled by a physiological parameter, e.g. heart potential {(evoked response A61N1/371)} · CPC title

• A61B5/7221

  Determining signal validity, reliability or quality (preventing, reducing or removing noise induced by motion artefacts A61B5/7207; noise originating from a therapeutic or surgical apparatus A61B5/7217) · CPC title

• A61B5/4836

  Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence) · CPC title