Use of detection profiles in an implantable medical device

Inventors

Allavatam, Venugopal

Assignees

Cameron Health Inc

Abstract

Implantable medical device systems and methods configured to use a detection profile selected from among a plurality of detection profiles to define a detection threshold for identifying cardiac events, in which a close call definition is used to determine which of the plurality of detection profiles is to be chosen. Upon identifying a close call, in which an overdetection nearly occurred but did not actually take place, a relatively less sensitive detection profile is chosen.

Core Innovation

Implantable cardiac monitoring and therapy devices receive cardiac signals from a plurality of electrodes and detect a plurality of cardiac events by comparing the cardiac signal to a detection threshold defined by a detection profile. The detection profile applies an initial refractory period after a cardiac event is detected during which additional cardiac events cannot be detected. After the refractory period, the detection profile applies at least a first detection period having a constant threshold and then a second detection period following the first detection period having a decaying threshold in which additional cardiac events can be detected if the cardiac signal crosses the detection threshold.

For the first detection period applied after a refractory period of a first of the plurality of detected cardiac events, the detection threshold is set by observing a signal peak during a corresponding first detection period applied after a refractory period of a second of the plurality of detected cardiac events and adding a margin to the observed signal peak. The first detection period precedes the second detection period, and the first of the plurality of detected cardiac events follows the second of the plurality of detected cardiac events, establishing a temporal relationship for how the prior signal peak is used to set the threshold for a subsequent detection period.

The described approach is applied in an implantable cardiac system with operational circuitry configured to analyze detected cardiac events and compare cardiac signals to the detection threshold defined by the detection profile, using the refractory period, constant threshold period, and decaying threshold period to enable detection of additional cardiac events. The disclosure also provides implantable system embodiments that include subcutaneous and transvenous architectures, and it includes downstream operational contexts such as defibrillation therapy decision and delivery, implantable cardiac monitor recording, and issuing a warning to a recipient based on likely arrhythmia determination.

Claims Coverage

The document provides two independent claims, a method claim and a system claim. Across these claims, there are five main inventive features: a refractory period with no additional detection, a sequential detection profile with a constant threshold period followed by a decaying threshold period, setting the first detection threshold using an observed signal peak from a corresponding earlier occurrence plus a margin, calculating that margin to create a detection threshold usable during the first detection period, and enforcing the temporal relationship that the first detected event follows the second detected event while the first detection period precedes the second detection period.

Overall claim coverage centers on detecting cardiac events with a profile that combines an initial refractory period with a constant-threshold period followed by a decaying threshold period, while adaptively setting the first post-refractory threshold from a prior observed signal peak plus a margin under a defined temporal ordering.

Stated Advantages

Documented Applications