256-channel parallel ultrasound open platform: Enabling high-resolution imaging and stimulation research

Background

Ultrasound imaging and stimulation are essential tools in various medical applications, enabling non-invasive diagnostics and targeted therapies. Ultrasound systems that integrate both imaging and stimulation capabilities offer a versatile solution for fundamental research. A high-performance, programmable platform allows researchers to customize system parameters and explore advanced imaging and stimulation techniques, playing a crucial role in driving innovation in both basic research and clinical applications.

Purpose

This study aims to introduce and validate a novel open ultrasound research platform designed to support both high-resolution imaging and effective ultrasound stimulation, thereby addressing current research needs in the biomedical field.

Methods

The proposed platform features 256 parallel transmit/receive channels, a 100 MHz sampling rate, 14-bit analog-to-digital converter resolution, and 10 Gb/s optical data transfer. It incorporates plane wave imaging and full matrix capture for high-resolution, real-time ultrasound imaging. Additionally, the system is capable of generating customized multi-cycle waveforms with pulse voltages up to 200 Vpp, enabling neuromodulation and therapeutic applications. It also offers a programmable development environment and compatibility with various phased array probes, providing flexibility for biomedical research. System performance was evaluated using a tissue-mimicking phantom and a 2 MHz transducer in phased array, plane wave imaging, and full matrix capture modes. Lateral resolution was evaluated using 150 µm tungsten wire imaging, while a 10 MHz transducer validated high-frequency imaging. A flexible transducer was tested for real-time imaging on curved surfaces with recalibration for distortion correction. The system's biomedical monitoring capability was demonstrated through carotid artery imaging, while acoustic field measurements, using a hydrophone, showcased its applicability in low-intensity focused ultrasound therapies.

Results

Imaging experiments using a tissue-mimicking phantom demonstrate that the platform achieves excellent lateral resolution of 100 µm in ultrasound imaging. Flexible transducer imaging demonstrated a notable improvement in image quality following recalibration, achieving over 100% enhancement. Real-time monitoring of the human common carotid artery demonstrated accurate dynamic imaging and quantification of heart and respiratory rates. For stimulation applications, hydrophone-based acoustic field measurements indicate that the system can generate peak positive pressures of up to 1.253 MPa, measured in an open field, reaching the threshold for effective ultrasound stimulation.

Conclusions

This study presents a 256-channel ultrasound research platform integrating imaging and stimulation functionalities. Through multi-mode imaging, flexible transducer imaging correction, carotid artery monitoring, and acoustic field measurements, the system's high resolution, real-time imaging, monitoring capability, and therapeutic potential were validated. These results demonstrate its effectiveness and versatility for advanced biomedical ultrasound applications.