被動影像導引聚焦超音波治療系統

Abstract

聚焦式超音波治療由於具備非侵入性和高安全性，近年來被認為有高度發展潛力。被動聲學成像（PAM）近年來也被發展成為一種新型工具，可以進行聚焦超音波之能量分布追蹤。本研究開發了一套被動影像導引聚焦超音波治療系統，旨在提出一種以新型態被動聲學成像進行聚焦超音波治療導引的想法實現。本研究中，系統的核心控制單元採用了現場可程式化邏輯閘陣列（FPGA），實現了靈活的同步發射與接收控制。接收端由FPGA 控制64 通道診斷探頭，發射端則透過FPGA 實現精確的脈衝發射信號，並搭配線性功率放大器，以確保訊號的低失真度。在本系統中，透過FPGA 的調整，使接收和發射系統具備不同工作頻率。同時，為了加快運算速度，本研究使用了新的查找技術，將運算時間從超過1 秒縮短10 倍至約100 毫秒。被動聲學成像實驗結果證實了發射與接收系統之間的精確同步。在保留傳統超音波成像功能上，系統可同時即時顯示被動成像技術即時追蹤聚焦超音波能量束，為治療過程提供了多元資訊。研究結果顯示所開發的被動影像導引聚焦超音波治療系統，不僅成功縮小了設備體積，還顯著提升了運算效率。該系統同時提供了不同成像模式，為未來便攜式超音波系統的發展提供了新的可能性。

Focused ultrasound therapy has garnered significant attention in recent years due to its non-invasive nature and high safety profile, making it a promising technology for future development. Similarly, Passive Acoustic Mapping (PAM) has emerged as a novel tool for tracking the energy distribution of focused ultrasound. This study developed a passive imaging-guided focused ultrasound therapy system, aiming to implement a novel concept for guiding focused ultrasound therapy using PAM. In this study, the core control unit of the system employs a Field-Programmable Gate Array (FPGA) to achieve flexible, synchronized control of both transmission and reception. The receiving unit is controlled by an FPGA to manage a 64-channel diagnostic probe, while the transmitting unit utilizes the FPGA to deliver precise pulsed signals and is paired with a linear power amplifier to maintain low signal distortion. Within the system, the FPGA allows the transmission and reception units to operate at different frequencies. Additionally, to accelerate computation speed, the study employed a novel lookup table technique, reducing processing time by tenfold—from over 1 second to approximately 100 ms. PAM experimental results demonstrated precise synchronization between the transmitting and receiving systems. The system retains traditional ultrasound imaging capabilities while simultaneously providing real-time passive imaging to track focused ultrasound energy beams, offering diverse information for the treatment process. The results indicate that the developed passive imaging-guided focused ultrasound therapy system not only successfully reduces the system’s size but also significantly enhances computational efficiency. The system offers different imaging modes, paving the way for future advancements in portable ultrasound systems.