IMD MRI Exposure Mode Configuration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable medical devices (IMDs) face issues when exposed to disruptive energy fields, such as those from MRI scanners, leading to inappropriate therapy delivery or withholding due to induced energy being detected as physiological signals, resulting in inadvertent stimulation or heating, which compromises therapy efficacy.
Innovation Solution
The IMD is configured to operate in specific exposure modes tailored for different types of MRI scanners, adjusting parameters like pacing amplitude, pulse width, and sensitivity to mitigate the effects of magnetic and RF fields, allowing it to distinguish between MRI scanners and adjust settings accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the IMD operates in a standard mode without distinguishing MRI scanner types, then the device operation is simple, but the therapy delivery becomes inaccurate due to induced energy being detected as physiological signals
Solution Approach 1:
The patent applies parameter changes by modifying operating parameters (pacing amplitude, pulse width, sensitivity thresholds) based on the detected MRI scanner type. The processor adjusts these parameters to compensate for induced energy effects specific to each scanner type, thereby maintaining detection accuracy without requiring complex hardware modifications.
Solution Approach 2:
The system dynamically switches between different exposure operating modes corresponding to different MRI scanner types (e.g., 1.5T vs. 3.0T). This dynamic adaptation allows the device to respond appropriately to varying disruptive field conditions, improving signal detection accuracy while managing complexity through automated mode selection.
2Productivity
If the IMD uses generic exposure operating mode for all MRI scanners, then the device complexity is reduced, but the therapy efficacy is compromised due to inadequate parameter adjustment for specific scanner types
Solution Approach 1:
The patent implements scanner-type-specific parameter adjustments, such as modifying pacing amplitude and pulse width based on the detected MRI scanner type. This targeted parameter modification ensures optimal therapy delivery efficacy for each scanner type while maintaining a manageable operating mode structure.
Solution Approach 2:
The exposure operating modes are segmented into distinct modes corresponding to different MRI scanner types (e.g., first exposure mode for 1.5T scanners, second exposure mode for 3.0T scanners). This segmentation allows specialized parameter sets to be applied to each scanner type, improving therapy efficacy without requiring a single complex universal mode.
3Reliability
If the IMD does not adjust parameters after MRI exposure, then the device operation remains simple, but pacing and sensing thresholds are compromised due to induced energy effects
Solution Approach 1:
The system performs preliminary parameter adjustments by detecting the MRI scanner type before and during exposure, and pre-configures appropriate operating parameters. This preliminary action ensures that pacing and sensing thresholds are maintained within reliable ranges throughout the exposure period, avoiding the need for complex real-time adjustments.
Solution Approach 2:
The patent incorporates feedback mechanisms where the processor continuously monitors physiological signals and adjusts parameters based on detected conditions. This feedback loop ensures that pacing and sensing thresholds remain stable and reliable during and after MRI exposure, compensating for induced energy effects through adaptive parameter modification.
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
This configuration reduces the adverse effects of disruptive energy fields, ensuring accurate therapy delivery and maintaining pacing and sensing thresholds, thereby enhancing the efficacy of IMD operations during and after exposure to MRI scanners.
Implementation Method 1
The disruptive energy field may induce energy on one or more of the implantable leads coupled to the IMD or directly on one or more components of the IMD
Implementation Method 2
the patient may need to have a magnetic resonance imaging (MRI) scan, computed tomography (CT) scan, electrocautery, diathermy or other medical procedure that produces a magnetic field, electromagnetic field, electric field or other disruptive energy field
Implementation Method 3
the induced energy on the leads or on the components of the IMD may result in inadvertent stimulation or heating of the tissue and/or nerve site adjacent to the electrodes of the leads or adjacent to the housing of the IMD
Data Source
AI summary
An implantable medical device (IMD) configures one or more operating parameters of the IMD based on a type of source of a disruptive energy field to which the IMD is exposed. The disruptive energy field may, in one example, include magnetic and/or radio frequency (RF) fields generated by an MRI scanner. In one aspect, the IMD may distinguish between different types of MRI scanners and select an exposure operating mode tailored to reduce the effects of the particular type of MRI scanner. In another aspect, the IMD may adjust one or more operating parameters that will be used when the IMD returns to a normal operating mode after exposure to the MRI scanner based on the type of MRI scanner to which the IMD is exposed.