Implantable medical device telemetry in disruptive energy field

Abstract

An implantable medical device may include a telemetry module, a sensing module, a therapy delivery module, and a processor. The processor may be configured to detect a patient event based on data generated by the sensing module, operate the IMD in a first mode in which the telemetry module is disabled and the therapy delivery module is at least partially disabled when the patient event is not detected, and operate the IMD in a second mode in which the telemetry module is enabled and the therapy delivery module is at least partially disabled when the patient event is detected. In some examples, the processor is configured to, in the second mode, generate a notification of the cardiac arrhythmia and transmit the notification to an external device via the telemetry module. The external device may reside inside an MRI room or outside the MRI room, and may communicate with other devices.

1 . An implantable medical device (IMD) comprising:
 a telemetry module;   a sensing module;   a therapy delivery module that provides cardioversion and/or defibrillation therapy; and   a processor configured to enter a magnetic resonance imaging (MRI)-compatible operating mode based on an indication of an MRI scan to be performed on a patient in which the IMD is implanted, wherein the cardioversion and defibrillation therapy is disabled while operating in the MRI-compatible operating mode and, while operating in the MRI-compatible operating mode, the processor being configured to:
 detect a patient event based on data generated by the sensing module, and 
 enable the telemetry module when the patient event is detected. 
   
     
     
         2 . The IMD of  claim 1 , wherein the sensing module is configured to sense electrical activity of a heart of the patient and generate the data based on the sensed electrical activity, and wherein the patient event comprises a cardiac arrhythmia. 
     
     
         3 . The IMD of  claim 2 , wherein the processor is configured to generate a notification of the cardiac arrhythmia and the telemetry module transmits the notification to an external device. 
     
     
         4 . The IMD of  claim 3 , wherein the notification comprises at least one of an indication of a cardiac arrhythmia, an indication of a type of the cardiac arrhythmia, or data representing a cardiac electrical signal. 
     
     
         5 . The IMD of  claim 3 , wherein the processor is configured to enable the telemetry module only when the cardiac arrhythmia comprises a ventricular tachycardia or a ventricular fibrillation. 
     
     
         6 . The IMD of  claim 1 , wherein the telemetry module is configured to receive a wireless communication from an external programmer device and the processor is configured to enter into the MRI-compatible operating mode in response to the wireless communication. 
     
     
         7 . The IMD of  claim 1 , further comprising a sensor configured to detect a magnetic field associated with an MRI device, the processor is configured to enter into the MRI-compatible operating mode in response to the sensor detecting the magnetic field associated with the MRI device. 
     
     
         8 . The IMD of  claim 1 , wherein the therapy delivery module is configured to provide pacing therapy while the IMD is operating in the MRI-compatible operating mode. 
     
     
         9 . The IMD of  claim 2 , wherein the processor, in response to detecting the patient event, controls therapy delivery module to deliver electrical stimulation therapy to the heart and determine whether the therapy delivered successfully terminated the cardiac arrhythmia, wherein the telemetry module is enabled when the electrical stimulation therapy is not successful. 
     
     
         10 . A method of operating an implantable medical device comprising:
 operating the IMD in a magnetic resonance imaging (MRI)-compatible operating mode based on an indication of an MRI scan to be performed on a patient in which the IMD is implanted, wherein cardioversion and defibrillation therapy is disabled while operating in the MRI-compatible operating mode;   while operating in the MRI-compatible operating mode, detecting a patient event based on data generated by a sensing module of the IMD;   enabling a telemetry module of the IMD when the patient event is detected.   
     
     
         11 . The method of  claim 10 , further comprising:
 generating a notification based on the detected patient event; and   transmitting the notification via the telemetry module to an external device while operating the IMD in the MRI-compatible operating mode.   
     
     
         12 . The method of  claim 10 , wherein detecting the patient event based on data generated by the sensing module of the IMD comprises detecting a cardiac arrhythmia. 
     
     
         13 . The method of  claim 11 , wherein enabling the telemetry module comprises enabling the telemetry module only when the cardiac arrhythmia comprises a ventricular tachycardia or a ventricular fibrillation. 
     
     
         14 . The method of  claim 10 , further comprising detecting the patient event during an MRI scan performed on the patient. 
     
     
         15 . The method of  claim 10 , further comprising receiving a wireless communication from an external device, wherein operating the IMD in the MRI-compatible operating mode comprises operating the IMD in the MRI-compatible operating mode in response to the wireless communication. 
     
     
         16 . The method of  claim 10 , detecting a magnetic field associated with an MRI device, wherein operating the IMD in the MRI-compatible operating mode comprises operating the IMD in the MRI-compatible operating mode in response to detecting the magnetic field associated with the MRI device. 
     
     
         17 . The method of  claim 10 , further comprising providing pacing therapy while the IMD is operating in the MRI-compatible operating mode. 
     
     
         18 . The method of  claim 11 , further comprising:
 delivering electrical stimulation therapy to the heart in response to detecting the cardiac arrhythmia, and   determining whether the therapy delivered successfully terminated the cardiac arrhythmia,   wherein enabling the telemetry module comprises enabling the telemetry module when the electrical stimulation therapy is not successful.