Implantable medical device with automatic tachycardia detection and control in MRI environments

摘要

An implantable medical device (IMD) includes a lead having one or more sensing electrodes and one or more therapy delivery electrodes, and a sensor configured to detect the presence of static and time-varying scan fields in a magnetic resonance imaging (MRI) environment. A controller, in electrical communication with the lead and the sensor, is configured to process signals related to tachycardia events sensed via the one or more sensing electrodes and to deliver pacing and shock therapy signals via the one or more therapy delivery electrodes. The controller compares the sensed static and time-varying scan fields to static and time-varying scan field thresholds. The controller controls delivery of anti-tachycardia pacing and shock therapy signals as a function of the detected tachycardia events, the comparison of the sensed static scan field to the static scan field threshold, and the comparison of the time-varying scan fields to the time-varying scan field thresholds.

主权项

1. An implantable medical device (IMD) comprising:
one or more leads configured to sense cardiac signals and deliver therapy signals; a sensor configured to detect the presence of static and time-varying scan fields in a magnetic resonance imaging (MRI) environment; and a controller configured to process detect cardiac event based on the cardiac signals, compare the sensed static and time-varying scan fields to static and time-varying scan field thresholds, and control delivery of a first type of stimulation therapy and a second type of stimulation therapy as a function of the detection of the cardiac events, the comparison of the sensed static scan field to the static scan field threshold, and the comparison of the time-varying scan fields to the time-varying scan field thresholds such that:
when the static and time-varying scan field thresholds are exceeded, the controller disqualifies the cardiac events to inhibit delivery of the first type of stimulation therapy and the second type of stimulation therapy, andwhen the static scan field threshold is exceeded and the time-varying scan field threshold is not exceeded, the controller processes sensed cardiac events, causes the IMD to deliver the first type of stimulation therapy upon detection of the cardiac events, and inhibits delivery of the second type of stimulation therapy.