Hall Sensor Mode Switching for MRI-Safe Implantable Devices
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Solution Overview
Problem
Implantable medical devices, such as cardiac rhythm management devices, face challenges in accurately sensing magnetic fields to switch between operating modes without using mechanical switches, which can be interfered with by large magnetic fields, potentially causing damage during procedures like MRI, and require a solid-state magnetic field sensor to prevent such issues.
Innovation Solution
Incorporating a Hall effect sensor integrated with a processor to sense magnetic fields and adjust operating modes, including a battery status test mode and MRI-safe mode, by providing current or voltage responses, allowing for real-time adjustments and preventing damage from external magnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a mechanical switch is used to switch between operating modes, then the device can change operating modes, but it can be interfered with by large magnetic fields and potentially damaged during MRI procedures
Solution Approach 1:
The patent replaces the mechanical switch with a solid-state Hall effect sensor that detects magnetic field strength and triggers operating mode changes through electronic control. This substitution eliminates moving parts that are susceptible to magnetic interference and physical damage, while maintaining the ability to switch between operating modes (ambulatory, battery status test, and MRI-safe modes) based on detected magnetic field conditions
2Reliability
If a solid-state Hall effect sensor is used to sense magnetic fields, then the device becomes resistant to magnetic field damage, but the device complexity increases
Solution Approach 1:
The patent integrates the Hall effect sensor, polling circuit, and processor into a unified solid-state system within the implantable medical device. The Hall effect sensor is electrically coupled to a polling circuit that applies excitation voltages, and both are connected to a processor that determines operating modes based on sensor output. This integration approach consolidates multiple components into a compact arrangement, reducing overall device complexity while maintaining magnetic field sensing capability and reliability
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 Hall effect sensor effectively switches the device between operating modes based on magnetic field strength, preventing damage from large magnetic fields and ensuring safe and continuous operation during procedures like MRI, while also providing battery status indications.
Implementation Method 1
a Hall effect sensor configured to sense a magnetic field and to provide at least one of a current or a voltage in response to the magnetic field
Data Source
AI summary
An implantable medical device can include a Hall effect sensor. The Hall effect sensor can include a first pair of electrical contacts and a second pair of electrical contacts. In an example, the Hall effect sensor can be configured to sense a magnetic field and can be configured to provide a voltage corresponding to a magnitude of the sensed magnetic field.