Development of Ultrasound Technology for Remote Acoustic Hemostasis Applications. The Remote Acoustic Hemostasis project funded under the Combat Casualty Care Research Program of the Army Medical Research and Materiel Command involves the development of a HIFU device with the potential for delivery of immediate, far-forward, and en-route care for soldiers sustaining life-threatening injuries on the battlefield.

Acute Effects of High Intensity Focused Ultrasound on Blood Vessels In-Vivo. An intraoperative experimental device has been developed that uses a focused beam of high intensity focused ultrasound waves to seal tissues. This device has the possibility of being able to stop bleeding from damaged blood vessels or internal organs; impressively, there is the possibility that this can be done without incising overlying tissues as the ultrasound beam can be focused at various tissue depths. Therefore, this technique may be a way to affect hemostasis and repair in a non-invasive manner, and thus advance the care of injured or surgical patients.

Investigators from NCPAs are conducting a preliminary study that will evaluate the effects of HIFU on blood vessels of the New Zealand White rabbits, as they contain blood vessels that are easily visualized and accessible and are large enough to obtain flow measurements. As the optimal parameters for HIFU to effect hemostasis on blood vessels are currently unknown, this study will measure the effects of varying doses and durations of HIFU on the blood vessels to discern optimal parameters to effect hemostasis, clotting, and the avoidance of tissue damage. Data from these experiments will be used to plan future experiments to define and refine the therapeutic capabilities of this exciting new device in greater depth.

Image-Guided HIFU Therapy. A system is currently being developed that will combine HIFU therapy, ultrasound imaging, cavitation monitoring, and control capabilities in a single, integrated treatment device. The backbone of the system is the Analogic Corp. AN2300 “Ultrasound Engine,” a PC-based open-architecture imaging machine that offers full access to the beamformed RF data stream. RF generators will drive the therapy array. The AN2300 will program the RF generators as well as control all aspects of HIFU exposure, treatment monitoring, and feedback control. In conjunction with the Analogic Corp. new knowledge and techniques will be used to for system modifications will then be installed for further testing.

Tissue Property Characterization and Cavitation Dynamics in Viscoelastic Media. The goal is to investigate the bubble dynamics in a viscoelastic material, such as soft tissue, which will include the thermal and mechanical effects of cavitation. Current work focuses on the measurement of viscoelastic properties of soft tissues in the megahertz frequency range and making efforts to develop an effective measurement method.