Leadless Pacemaker MRI Detection and Safe Mode Switching

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Implantable cardiac devices face challenges in safely operating during MRI procedures due to strong magnetic fields, which can interfere with their functionality and require mechanisms to adjust operations and communicate safety modes.

Innovation Solution

A cardiac rhythm management system comprising two implantable medical devices that detect MRI magnetic fields, communicate their presence, and switch to an MRI-safe mode, modifying therapy or ceasing operations until the field is cleared, ensuring safe operation during MRI procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If implantable cardiac devices operate during MRI procedures, then continuous cardiac monitoring and therapy delivery can be maintained, but device functionality may be interfered with by strong magnetic fields

Engineering Contradiction:

Improvecontinuous cardiac monitoring and therapy deliveryVSAvoidinterference from MRI magnetic fields

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The device enters a pre-programmed MRI-safe mode upon detecting the presence of an MRI scanner, before actual MRI imaging begins. This preliminary action allows the device to proactively adjust its operation to prevent interference from magnetic fields, rather than reacting after interference occurs. The device detects MRI approach and automatically modifies pacing and sensing parameters in advance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The device dynamically adjusts its operational parameters based on the detected MRI environment. It transitions from normal operating mode to MRI-safe mode, modifying pacing rates, sensing thresholds, and other parameters in real-time according to the MRI scan status. This dynamic adaptation allows the device to maintain cardiac monitoring and therapy delivery while accommodating the changing magnetic field conditions during MRI procedures.

Inventive Principle:

Principle #15Dynamics

2Loss of information

If implantable devices communicate MRI-safe mode status to patients, then patient awareness and safety can be improved, but additional communication components and complexity are required

Engineering Contradiction:

Improvepatient awareness of device statusVSAvoidcommunication components and programming

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The device utilizes its existing communication infrastructure, including wireless telemetry and indicator LEDs, to convey MRI-safe mode status to patients and clinicians. Rather than adding dedicated communication hardware, the system repurposes existing components for dual functions: normal device communication and MRI status indication. This multi-functional approach reduces additional complexity while maintaining patient awareness capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If devices automatically detect and respond to MRI magnetic fields, then safety during MRI procedures is improved, but detection sensitivity and false alarm risks increase device complexity

Engineering Contradiction:

Improvesafety during MRI proceduresVSAvoiddetection mechanisms and threshold programming

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The device employs pre-programmed magnetic field detection thresholds that are optimized to distinguish between normal environmental magnetic fields and the stronger fields generated by MRI scanners. By carefully selecting and programming these detection parameters, the device achieves reliable MRI detection while minimizing false alarms. The detection system monitors magnetic field strength and triggers MRI-safe mode only when thresholds indicative of MRI presence are exceeded.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively manages cardiac rhythm and therapy delivery during MRI scans by detecting magnetic fields and adjusting device functions, ensuring patient safety and device integrity.

Implementation Method 1

The first implantable medical device is configured to detect a magnetic field indicative of an MRI

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

the first implantable medical device of the first example is configured to communicate the presence of the magnetic field indicative of an MRI via conducted communication

Methodology Applied

Scientific EffectConducted communication: Conduction (electrical)

Data Source

PatentUS9457182B2Leadless cardiac pacemaker with MRI pacing mode

Publication Date: 2016.10.04 CARDIAC PACEMAKERS INC

AI summary

A cardiac rhythm management system includes a first implantable medical device configured to monitor a patient's heart rhythm and provide therapy if appropriate, and a second implantable medical device that is configured to monitor the patient's heart rhythm and provide therapy if appropriate. The first implantable medical device is configured to detect a magnetic field indicative of an MRI machine and, upon detecting a magnetic field indicative of an MRI machine, is further configured to communicate the presence of the magnetic field indicative of the MRI machine to the second implantable medical device. The second implantable medical device may then enter an MRI-safe mode.