Multi-threshold sensing of cardiac electrical signals in an extracardiovascular implantable cardioverter defibrillator
First Claim
1. A system comprising an implantable medical device for sensing cardiac electrical events, the system comprising:
- a sensing circuit configured to;
receive a cardiac electrical signal from electrodes coupled to the implantable medical device;
sense a plurality of cardiac events, each one of the plurality of cardiac events attendant to a myocardial depolarization and sensed in response to the cardiac electrical signal crossing a cardiac event sensing threshold; and
after each sensed cardiac event, adjust the cardiac event sensing threshold to a starting threshold value for sensing a next one of the plurality of cardiac events;
a control circuit configured to;
determine a gain based on a minimum threshold value;
determine a maximum limit of the starting threshold value based on the gain and the minimum threshold value of the cardiac event sensing threshold;
control the sensing circuit to set the starting value of the cardiac event sensing threshold after each sensed cardiac event to be equal to or less than the maximum limit; and
detect an arrhythmia based on the plurality of cardiac events sensed by the sensing circuit; and
a therapy delivery circuit configured to generate and deliver an electrical stimulation therapy to a patient'"'"'s heart via the electrodes coupled to the implantable medical device in response to the control circuit detecting the arrhythmia.
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Accused Products
Abstract
An implantable medical device system capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient'"'"'s heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.
56 Citations
29 Claims
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1. A system comprising an implantable medical device for sensing cardiac electrical events, the system comprising:
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a sensing circuit configured to; receive a cardiac electrical signal from electrodes coupled to the implantable medical device; sense a plurality of cardiac events, each one of the plurality of cardiac events attendant to a myocardial depolarization and sensed in response to the cardiac electrical signal crossing a cardiac event sensing threshold; and after each sensed cardiac event, adjust the cardiac event sensing threshold to a starting threshold value for sensing a next one of the plurality of cardiac events; a control circuit configured to; determine a gain based on a minimum threshold value; determine a maximum limit of the starting threshold value based on the gain and the minimum threshold value of the cardiac event sensing threshold; control the sensing circuit to set the starting value of the cardiac event sensing threshold after each sensed cardiac event to be equal to or less than the maximum limit; and detect an arrhythmia based on the plurality of cardiac events sensed by the sensing circuit; and a therapy delivery circuit configured to generate and deliver an electrical stimulation therapy to a patient'"'"'s heart via the electrodes coupled to the implantable medical device in response to the control circuit detecting the arrhythmia. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method performed by a system comprising an implantable medical device for sensing cardiac electrical signals, comprising:
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receiving a cardiac electrical signal by a sensing circuit of the implantable medical device via electrodes coupled to the implantable medical device; setting a cardiac event sensing threshold to a starting threshold value; sensing a cardiac event attendant to a myocardial depolarization in response to the cardiac electrical signal crossing the cardiac event sensing threshold; detecting an arrhythmia based on a plurality of cardiac events sensed by the sensing circuit; and generating and delivering an electrical stimulation therapy by a therapy delivery circuit in response to detecting the arrhythmia, wherein setting the starting threshold value comprises; determining by a control circuit of the implantable medical device a gain based on a minimum threshold value of the cardiac event sensing threshold; determining a maximum limit of the starting threshold value based on the gain and the minimum threshold value; and setting the starting value of the cardiac event sensing threshold to be equal to or less than the maximum limit. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A non-transitory, computer-readable storage medium comprising a set of instructions which, when executed by processor of an implantable medical device system, cause the system to:
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set a cardiac event sensing threshold to a starting threshold value; sense a cardiac event attendant to a myocardial depolarization by a sensing circuit of the implantable medical device in response to a cardiac electrical signal crossing the cardiac event sensing threshold; detect an arrhythmia based on a plurality of cardiac events sensed by the sensing circuit; and generate and deliver an electrical stimulation therapy by a therapy delivery circuit of the implantable medical device in response to detecting the arrhythmia, wherein setting the cardiac event sensing threshold to the starting threshold value comprises; determining a gain based on a minimum threshold value of the cardiac event sensing threshold; determining a maximum limit of the starting threshold value based on the gain and the minimum threshold value; and setting the starting value of the cardiac event sensing threshold to be equal to or less than the maximum limit.
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Specification