Deep bleeder acoustic coagulation (DBAC)-Part I: development and in vitro testing of a research prototype cuff system

Area of Science:

• Biomedical Engineering
• Medical Devices
• Ultrasound Technology

Background:

• Limb bleeding from battlefield injuries is a significant cause of mortality, particularly for deep wounds.
• High-intensity focused ultrasound (HIFU) offers potential for non-invasive coagulation of deep bleeding.
• Development of an ultrasound research prototype deep bleeder acoustic coagulation (DBAC) cuff system for battlefield evaluation.

Purpose of the Study:

• To develop and evaluate an in vitro prototype DBAC cuff system for battlefield deep wound hemostasis.
• To meet quantitative performance metrics including automated operation, therapeutic heating, bleeder detection, targeting accuracy, and operational time.
• To drive innovation in image segmentation, bleeder detection, therapy transducers, beam targeting, and dose monitoring.

Main Methods:

• Utilized 3D ultrasound (US) imaging probes for detection and localization (D&L) and targeting.
• Employed automated spectral Doppler analysis for bleeder identification and novel high-element-count therapeutic arrays.
• Integrated spatial registration, acoustic time-of-flight, fiber optic tracking, ARFI/TSI for closed-loop targeting, and RNN acoustic thermometry for closed-loop dosing.

Main Results:

• The DBAC cuff met most performance requirements, including weight, power delivery, targeting accuracy, and autonomous operation.
• Automated D&L achieved 65% success, detecting small bleeders but struggling with low-flow bleeders and smaller phantom sizes.
• Closed-loop targeting converged in 71% of tests, and closed-loop dosing with power shut-off at preset temperature changes was operational.

Conclusions:

• The prototype DBAC cuff met main performance objectives, necessitating significant new technology development.
• Novel therapeutic arrays, advanced imaging, and RNN acoustic thermometry enabled key functionalities like automated D&L and feedback-controlled dosing.
• While not all specifications were met, future engineering solutions are proposed, and complex limb test phantoms performed well.