A modular 16-channel high-voltage ultrasound phased array system for therapeutic medical applications

In a recently published study in the journal EPSL neuroelectronics, researchers from The Pennsylvania State University and Washington University in St. Louis have introduced a modular 16-channel high-voltage ultrasound phased array system for therapeutic applications. This system enables noninvasive ultrasound medical interventions such as neuromodulation and blood-brain barrier disruption. It offers flexible programmable sonication parameters, delivers high ultrasound pressure outputs, and achieves millimeter-level spatial precision, making it suitable for a wide range of basic research and clinical purposes.

The noninvasive nature of ultrasound (US), combined with its precision when focused, has positioned it as an attractive tool for a range of therapeutic medical applications. Among these applications, focused ultrasound (FUS) has particularly gained significant attention for targeting the brain. FUS has been successfully employed for various therapeutic purposes such as neuromodulation, temporary blood-brain barrier (BBB) disruption, and thermoablation.

A research team led by Dr. Mehdi Kiani from The Pennsylvania State University has developed a modular 16-channel high-voltage ultrasound phased array system, which offers a high degree of flexibility in sonication waveform generation and US pressure control for focusing and steering ultrasound beams.

“With precise beam focusing and steering capability and high ultrasound pressure output, this system offers a robust tool for a wide range of ultrasound-based therapeutic applications,” says Dr. Kiani, the project supervisor. “The system's functionality is thoroughly demonstrated across different steering angles and driving voltages, showcasing its versatility. Analytical and experimental evaluations confirm its efficient operation and reliable performance, even for extended sonication durations.”

Unlike conventional systems with single-element transducers, which are limited in spatial coverage, this phased array system electronically steers and focuses ultrasound beams. The system provides a wide range of sonication parameters and generates high voltage outputs across ultrasound transducer array over extended duration. These are critical for adapting the system to diverse experimental and clinical needs across different animal and human subjects.

“The electronics can drive a piezoelectric transducer array with pulses up to 100 V at 2 MHz frequency, achieving a peak-peak ultrasound pressure output of 6 MPa at 10 mm focal depth without significant sidelobes. Also, the circuits have been developed in a modular fashion that can easily extend the phased array system to higher number channel if needed.” explains Ardavan Javid, lead author of the study who is currently a PhD student at the Integrated Circuits and Systems Laboratory at the Pennsylvania State University.   

The system's potential was validated through in vivo experiments performed by Dr. Hong Chen’s research group at Washington University in St. Louis. Their findings highlight the system’s effectiveness for applications involving ultrasound stimulation in multiple brain locations, including BBB opening for large-volume brain drug delivery, noninvasive neuromodulation of multiple brain regions, or management of widespread pathological processes, such as amyloid plaque reduction in Alzheimer's disease or diffuse tumor therapy in glioblastoma.

"The ultrasound phased array is a technology breakthrough in the field. Our research has demonstrated its effectiveness in non-invasively opening the BBB, facilitating targeted drug delivery to the brain. This achievement paves the way for broader applications of this array, including the development of wearable phased arrays for flexible neuromodulation." says Dr. Chen. 

This innovative phased array system represents a robust solution for advanced US therapeutic applications, combining high acoustic pressure output, precise and dynamic beam focusing and steering, and flexible operation. This work was supported by the National Institutes of Health, the Office of Naval Research, and the National Science Foundation.

This paper was published in EPSL Neuroelectronics. Javid A, Biswas R, Ilham S, Chukwu C, Yang Y, Chen H, and Kiani M. A modular 16-channel high-voltage ultrasound phased array system for therapeutic medical applications. Neuroelectronics 2024(1):0004,

https://doi.org/10.55092/neuroelectronics20240004.

DOI: 10.55092/neuroelectronics20240004