A Fully MRI-Compatible, Non-Electrical System for Near Real-Time Tremor Monitoring During MR-guided Focused...

Area of Science:

• Medical Devices
• Neurology
• Biomedical Engineering

Background:

• Essential tremor (ET) quantification during MR-guided Focused Ultrasound (MRgFUS) is challenging.
• Existing methods like accelerometry face limitations including electromagnetic interference and MRI incompatibility.
• Accurate, real-time tremor monitoring synchronized with sonication is crucial for effective treatment.

Purpose of the Study:

• To develop a fully MRI-compatible, non-electrical system for continuous, artifact-free tremor monitoring.
• To enable near real-time frequency analysis and precise synchronization with ultrasound delivery.
• To provide in-situ tremor amplitude data for improved targeting during MRgFUS verification.

Main Methods:

• A pneumatic device utilizing an endotracheal cuff inflated to a fixed pressure was designed.
• Pressure fluctuations from tremor were transmitted and digitized using a custom Arduino-based system.
• Software was developed for near real-time calculation of tremor amplitude.

Main Results:

• The system enabled real-time tremor visualization and assessment of tremor reduction in 10 patients.
• A mean tremor reduction of 86% was observed immediately after verification sonication.
• This confirmed accurate targeting, with one patient requiring target adjustment due to sensory side effects.

Conclusions:

• A near real-time pressure system for tremor amplitude quantification during MRgFUS sonications was successfully developed.
• The system is inexpensive, MRI-compatible, and easily implemented for patients undergoing MRgFUS.
• It effectively avoids information loss between temporary tremor reduction and clinical evaluation.