Medtronic, Inc.

Vitatron Medical B. V.

Volkert A Zeijlemaker

James D Reinke

Steven D Goedeke

Laurie D Foerster

Ron Kalin

Yong Kyun Cho

Gregory Anthony Hrdlicka

Jeffrey David Wilkinson

Gustaaf A P Stoop

Bernardus F M Vonk

Chester L Struble

Malcolm J Begemann

Pierre Andre Grandjean

Nicolaas M Lokhoff

Karel F A A Smits

Christopher C Stancer

Karel Den Dulk

Henny M Leerssen

A detection unit and a method for detecting an implanted medical device in an MRI environment employ a telemetry transmission from the implanted medical device.

Implantable medical device detection

Electrode systems that may be used with implantable medical devices such as a pacemaker, in addition to one or more conventional electrodes, include a shunt electrode. Under ordinary conditions, the shunt electrode has very little effect upon the operation of the electrode system. When high frequency current is delivered to the electrode system, however, the electrode system shunts a large share of the high frequency current to the shunt electrode. The shunt electrode, which includes a conducting material surrounded by an insulating layer, dissipates heat that may be caused by the high frequency current.

Electrode system with shunt electrode

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.

Implantable medical device telemetry in disruptive energy field

A medical device includes a sensor for sensing for an MRI gradient magnetic field and a microprocessor configured to operate in a signal processing mode in which electrical signals induced by the gradient magnetic field are not counted as cardiac events.

Medical device sensing and detection during MRI

Polarization signals, which represent voltages measured at a pacemaker electrode, are not constant and may drift. Polarization signal drift, which often precedes undesirable pace polarization artifacts, is more significant when the pacemaker is inhibited from providing an electrical stimulation to the patient's heart. The present invention provides an implantable system and methods for stabilization of a polarization signal. Electrical pulses may be applied to stabilize a polarization signal. In one implementation of the invention, polarization signal stabilization may be used as part of process to terminate tachycardia.

Intracardiac polarization signal stabilization

An implantable medical device (IMD) can include a cardiac pacemaker or an implantable cardiac defibrillator (ICD). Various portions of the IMD, such as a case or device body, the lead body, or the lead tip, can be provided to reduce or dissipate a heat production due to a current induced by various external environmental factors. According to various embodiments, features or portions can be incorporated into the lead body, the lead tip, or the IMD body to reduce the creation of an induced current, or dissipate or increase the area of dissipation of thermal energy created due to an induced current in the lead.

System and method for shunting induced currents in an electrical lead

The invention is directed to structure and methods for coordinating the operation of an implantable medical device (IMD) with magnetic resonance imaging (MRI) techniques. For example the IMD can be made to activate a blanking period during the time when the electromagnetic radiation bursts occur. Blanking an IMD at times when MRI electromagnetic radiation bursts occur can prevent an undesirable action or incorrect sensing by the IMD while under the influence of the electromagnetic radiation bursts.

Controlling blanking during magnetic resonance imaging

The disclosure is directed to techniques in which magnetic resonance imaging (MRI) is coordinated with the operation of an implantable medical device (IMD). By using an IMD to sense conditions, MRI can be improved because the sensed conditions can accurately define timing for application of electromagnetic radiation bursts. Moreover, by applying stimulation pulses specifically to coordinate the electromagnetic radiation bursts, the MRI may also be improved.

Timing techniques for magnetic resonance imaging

Upon delivery of a pacing pulse to a heart by an electrode of an implantable medical device (IMD), a deleterious pace polarization artifact is generally created at the electrode-tissue interface and subsequently stored by the electrode. Such polarization artifact is generally minimized through the use of passive recharge circuitry. Such passive recharge circuitry functions in creating a recharge pulse at the electrode which in essence, minimizes the polarization artifact on the electrode. In order to produce further artifact minimization from a subsequent pacing pulse, following termination of the recharge pulse, any remaining polarization artifact is sampled and analyzed by the IMD and IMD software optionally compensates the next recharge pulse to further minimize the polarization artifact generated by a next pacing pulse. This sampling and optional compensation is repeated for subsequent pacing pulses so that polarization artifacts are effectively analyzed and if necessary, minimized.

System for waveform stimulation compensating electrode polarization

A medical device includes a sensor for sensing for an MRI gradient magnetic field and a microprocessor for responding to the detected gradient magnetic field by switching from a first electrical signal processing mode to a second electrical signal processing mode, such that electrical signals induced by the gradient magnetic field and an associated RF burst are not counted as cardiac events.

The invention is directed to techniques in which magnetic resonance imaging (MRI) is coordinated with the operation of an implantable medical device (IMD). By using an IMD to sense conditions, MRI can be improved because the sensed conditions can accurately define timing for application of electromagnetic radiation bursts. Moreover, by applying stimulation pulses specifically to coordinate the electromagnetic radiation bursts, the MRI may also be improved.

The invention is directed techniques for coordinating telemetry of medical devices with magnetic resonance imaging (MRI) techniques. By coordinating telemetry of a medical device with the performance of MRI techniques with, the use of telemetry during MRI may be facilitated. In one example, information indicative of electromagnetic radiation bursts in MRI techniques can be communicated to the medical device prior to execution. In another example, the medical device may identify the electromagnetic radiation bursts, e.g., by measuring for the presence of such bursts. In either case, the medical device can adjust its telemetry to improve communication during MRI.

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Landgraaf, Netherlands

Volkert A Zeijlemaker