Device and method for determining a cardiac sensing control parameter

Patent metadata

Field	Value
Publication number	US-2024050755-A1
Application number	US-202318496781-A
Country	US
Kind code	A1
Filing date	Oct 27, 2023
Priority date	Jun 29, 2020
Publication date	Feb 15, 2024
Grant date	—

Abstract

A medical device processor is configured to receive a first cardiac electrical signal sensed from a first sensing electrode vector, receive a second cardiac electrical signal sensed from a second sensing electrode vector different than the first sensing electrode vector, and construct a third cardiac electrical signal from the first cardiac electrical signal and the second cardiac electrical signal. In some examples, the system determines sensed cardiac events according to at least one setting of a cardiac event sensing threshold control parameter from at least the third cardiac electrical signal and may determine at least one acceptable setting of a sensing control parameter based on the determined sensed cardiac events. The processor may generate an output representative of the determined sensed cardiac events.

First claim

What is claimed is:

1 . A medical device system comprising:
a processor configured to:
receive a first cardiac electrical signal and a second cardiac electrical signal associated with a tachyarrhythmia;
construct a third cardiac electrical signal from the first sensed cardiac electrical signal and the second sensed cardiac electrical signal;
determine a first predicted time to detect the tachyarrhythmia from the constructed third cardiac electrical signal;
determine at least one acceptable setting of a sensing control parameter based on at least the first predicted time to detect the tachyarrhythmia from the constructed third cardiac electrical signal; and
generate an output based on the determined acceptable setting of the sensing control parameter.

2 . The medical device system of claim 1 , wherein the processor is further configured to:
determine at least the first predicted time and a second predicted time to detect the tachyarrhythmia from the constructed third cardiac electrical signal by:
determining the first predicted time according to a first setting of a plurality of settings of the sensing control parameter; and
determining the second predicted time according to a second setting of a plurality of settings of the sensing control parameter; and
determine the at least one acceptable setting of the sensing control parameter based on at least the first predicted time to detect the tachyarrhythmia and the second predicted time to detect the tachyarrhythmia.

3 . The medical device system of claim 1 , wherein the processor is further configured to:
for at least one of the first cardiac electrical signal, the second cardiac electrical signal and the constructed third cardiac electrical signal, determine a plurality of predicted times to detect the tachyarrhythmia, where each of the plurality of predicted times to detect the tachyarrhythmia are determined for a respective one of a plurality of settings of the sensing control parameter; determine that at least one of the plurality of the predicted times to detect the tachyarrhythmia is within a tachyarrhythmia detection time limit; and determine the at least one acceptable setting of the sensing control parameter by identifying at least one of the plurality of settings of the sensing control parameter for which the determined predicted time of the plurality of predicted times to detect the tachyarrhythmia is within the tachyarrhythmia detection time limit.

4 . The medical device system of claim 3 , wherein the processor is further configured to:
receive an actual time to detect the tachyarrhythmia from one of the first cardiac electrical signal or the second cardiac electrical signal; and determine the tachyarrhythmia detection time limit by:
determining a minimum time to detect the tachyarrhythmia from among the actual time to detect the tachyarrhythmia, the first predicted time to detect the tachyarrhythmia from the constructed third cardiac electrical signal, and the plurality of predicted times to detect the tachyarrhythmia; and
determining the tachyarrhythmia detection time limit based on the minimum time to detect the tachyarrhythmia.

5 . The medical device system of claim 3 wherein the processor is further configured to:
determine each of the plurality of predicted times to detect the tachyarrhythmia for the respective one of the plurality of settings of the sensing control parameter by determining each of the plurality of predicted times to detect the tachyarrhythmia for each of a plurality of sensitivity settings used to set a lowest amplitude of a cardiac event sensing threshold; and
determine the at least one acceptable setting of the sensing control parameter by:
determining a highest value of the plurality of sensitivity settings for which the determined predicted time to detect the tachyarrhythmia is within the tachyarrhythmia detection time limit; and
determining the at least one acceptable setting of the sensing control parameter by determining a sensitivity that is a factor of the highest value of the plurality of sensitivity settings for which the determined predicted time to detect the tachyarrhythmia is within the tachyarrhythmia detection time limit.

6 . The medical device system of claim 1 wherein the processor is further configured to determine the first predicted time to detect the tachyarrhythmia from the constructed third cardiac electrical signal by:
determining sensed cardiac events from the constructed third cardiac signal;
determining sensed cardiac event intervals from the sensed cardiac events; and
determining the first predicted time to detect the tachyarrhythmia based on the determined sensed cardiac event intervals.

7 . The medical device system of claim 1 wherein the processor is further configured to determine the at least one acceptable setting of the sensing control parameter by determining at least one of:
a sensing electrode vector;
a sensitivity used to set a cardiac event sensing threshold amplitude;
a percentage used to set a starting amplitude of the cardiac event sensing threshold amplitude;
a percentage used to set an intermediate amplitude of the cardiac event sensing threshold amplitude; or
a time interval used for making an amplitude adjustment to the cardiac event sensing threshold amplitude.

8 . The medical device system of claim 1 further comprising
a sensing circuit configured to sense a first cardiac electrical signal and a second cardiac electrical signal;
a control circuit configured to detect a tachyarrhythmia from at least one of the first cardiac electrical signal and the second cardiac electrical signal; and
a therapy delivery circuit configured to deliver a therapy in response to the control circuit detecting the tachyarrhythmia.

9 . The medical device system of claim 8 further comprising:
an implantable medical device comprising:
a housing enclosing the sensing circuit, the control circuit and the therapy delivery circuit; and
a first telemetry circuit configured to transmit the first cardiac electrical signal, the second cardiac electrical signal and the actual time to detect the tachyarrhythmia; and

an external device comprising:
a second telemetry configured to receive the first cardiac electrical signal, the second cardiac electrical signal transmitted by the first telemetry circuit;
the processor configured to receive the first cardiac electrical signal, the second cardiac electrical signal and the actual time to detect the tachyarrhythmia via the second telemetry circuit; and
a display unit configured to display the output generated by the processor.

10 . The medical device system of claim 9 , wherein
the processor is further configured to:
for at least one of the first cardiac electrical signal, the second cardiac electrical signal and the constructed third cardiac electrical signal, determine a plurality of predicted times to detect the tachyarrhythmia, where each of the plurality of predicted times to detect the tachyarrhythmia are determined for a respective one of a plurality of sensitivity settings;
generate the output by:
for each one of the plurality of sensitivity settings determining a safety margin for sensing cardiac events; and
determining the at least one acceptable sensing control parameter by determining an acceptable sensitivity setting based on at least the determined safety margins and the plurality of predicted times to detect the tachyarrhythmia; and

the display unit is further configured to display at least a portion of the plurality of predicted times to detect the tachyarrhythmia along with a corresponding sensitivity setting and a corresponding determined safety margin.

Assignees

• Medtronic Inc

Inventors

• Zhang Xusheng
• Liu Yuanzhen

Classifications

• A61N1/3702 Primary

  Physiological parameters (A61N1/365 takes precedence; evoked response A61N1/371) · CPC title

• A61N1/3625

  External stimulators · CPC title

• A61N1/39622

  Pacing therapy · CPC title

• A61B5/363 Primary

  Detecting tachycardia or bradycardia · CPC title

• A61B5/341

  Vectorcardiography [VCG] · CPC title