Cochlear Implant MRI Telemetry via Electrode Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic Resonance Imaging (MRI) poses risks to patients with implantable electronic devices like cochlear implants due to MRI-induced tissue heating and unintended neural stimulation, leading to safety concerns and restrictions on MRI usage.
Innovation Solution
An MRI telemetry module is integrated into the cochlear implant system to measure electrode currents induced during MRI and output a telemetry signal representing tissue temperature, allowing for real-time monitoring and safe MRI procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If MRI is performed on patients with implantable electrode devices, then diagnostic imaging can be obtained, but tissue heating and unintended neural stimulation occur causing safety risks
Solution Approach 1:
The patent implements a feedback mechanism by measuring the impedance of the electrode lead during MRI and comparing it to pre-stored impedance values at known temperatures. This allows the system to monitor temperature changes in real-time and provide feedback to control the MRI heating process, preventing excessive tissue heating while maintaining diagnostic imaging capability
Solution Approach 2:
The patent replaces direct temperature measurement with an electrical measurement system. Instead of using thermal sensors that would require physical contact with tissue, the system uses electrical impedance measurements of the electrode lead to infer temperature, substituting a mechanical/thermal measurement approach with an electrical one that is safer and more practical for implanted devices
2Object-affected harmful factors
If electrode wire coiling is used to improve MRI safety, then tissue heating is reduced, but device complexity and space requirements increase
Solution Approach 1:
The patent changes the parameter being monitored from direct temperature or current measurement to electrical impedance. By measuring impedance changes in the electrode lead, the system can infer temperature without requiring complex structural modifications like coiling, thus reducing device complexity while maintaining safety monitoring capability
Solution Approach 2:
The patent introduces electrical impedance as an intermediary parameter that correlates with temperature but can be measured without direct thermal contact or complex structural changes. This intermediary measurement approach allows temperature monitoring while avoiding the need for electrode wire coiling or other complex structural modifications
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 solution enables safe MRI procedures by accurately measuring tissue heating and preventing overheating or unintended neural stimulation, thereby reducing the risk of damage to the implant and surrounding tissue.
Implementation Method 1
measure electrode current induced in the electrode lead during an MRI process
Implementation Method 2
configured to deliver electrode stimulation signals carried by the electrode wires to adjacent auditory neural tissue
Implementation Method 3
interactions with the induced RF pulses can lead to MRI-induced tissue heating near the elongated electrode leads
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A magnetic resonance imaging (MRI) telemetry arrangement and process for a cochlear implant system are described. Electrode current is measured that is induced in a cochlear implant electrode lead during an MRI process performed on an implanted patient. An MRI telemetry signal for an external telemetry sensor is then output based on the measured electrode current.