Fiber-Based Clock Synchronization Method for Medical Ultrasound System.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Ultrasound Technology

Background:

• Brain ultrasound offers noninvasive treatment but faces challenges with skull penetration.
• Phase correction techniques are essential for skull compensation in therapeutic ultrasound.
• Large-element arrays are needed for broad tissue coverage, requiring precise clock synchronization.

Purpose of the Study:

• To develop and validate an optical fiber-based clock synchronization system for MRI-guided, large-scale ultrasound array applications.
• To address the limitations of traditional clock schemes in synchronizing thousands of transducer elements.
• To ensure MRI compatibility for integrated ultrasound interventions.

Main Methods:

• An optical fiber system was designed for simultaneous clock distribution and full-duplex data transmission.
• The system was tested for clock synchronization precision (<557 ps) and period jitter (<10 ps rms) at 50 MHz.
• Synchronization accuracy between multiple ultrasonic systems (<10 ns error) was evaluated using 1-MHz transducers.

Main Results:

• The proposed optical fiber system achieved high-precision clock synchronization (<557 ps) and low jitter (<10 ps rms).
• It successfully synchronized multiple 128- or 256-channel ultrasonic systems with inter-channel errors below 10 ns.
• The system demonstrated MRI compatibility, functioning within an MRI scanning room and communicating via a single fiber.

Conclusions:

• The optical fiber-based clock synchronization is a viable solution for large-scale ultrasound arrays in MRI-guided interventions.
• This method overcomes the limitations of traditional clocking systems for advanced brain ultrasound therapies.
• Successful in vivo primate studies confirm the system's suitability for clinical translation.