An optically powered CMOS tracking system for 3 T magnetic resonance environment

Area of Science:

• Biomedical Engineering
• Medical Imaging Technology
• Optical Systems

Background:

• Conventional wired catheter tracking systems for MRI face challenges with radiofrequency (RF) induced heating.
• Accurate and safe catheter navigation within the MRI environment is crucial for interventional procedures.

Purpose of the Study:

• To present a fully optical Complementary Metal Oxide Semiconductor (CMOS) based catheter tracking system for 3 Tesla (3 T) Magnetic Resonance Imaging (MRI).
• To address and mitigate the RF-induced heating issues associated with traditional wired systems in MRI environments.

Main Methods:

• Development of an integrated circuit comprising an optical power supply unit with a photodiode and DC-DC converter, and a direct conversion receiver.
• Utilization of an optically driven switch controlled by light modulation for power transfer.
• Integration of an on-chip local oscillator avoidance strategy using MRI-generated RF signals.
• Optical data transfer for processed signals and frequency encoding for MRI tracking.

Main Results:

• The system successfully operates without noticeable temperature increases across various optical power levels.
• Demonstrated full functionality and successful testing within a 3 T MRI machine.
• The optical power supply unit effectively boosts low photodiode voltage to over 1.5 V.

Conclusions:

• The presented fully optical CMOS-based system offers a safe and effective solution for catheter tracking in 3 T MRI.
• The novel optical switching and power delivery mechanism overcomes limitations of conventional wired systems.
• This technology holds promise for enhancing the safety and precision of MRI-guided interventions.