基於現場可程式化邏輯閘陣列控制之高功率驅動系統 設計應用於高強度聚焦式超音波

Abstract

近年來，高強度聚焦超音波（HIFU）治療因其非侵入性治療方式和優異的臨床成效，受到廣泛的關注，已成為臨床實踐中不可或缺的關鍵因素。隨著HIFU技術的不斷發展和改進，對於驅動電路的要求也越來越高，以確保治療過程的安全和有效。相較於單通道聚焦式超音波驅動系統的固定聚焦位置以及深度，多通道相位控制的聚焦式超音波系統擁有可調式聚焦深度及位置更加靈活，也越來越多研究致力研究於多通道聚焦式超音波系統中。然而傳統的非線性驅動電路除了在輸出上擁有高次諧波，造成聲場的旁瓣效應進而影響治療效外，在阻抗匹配上也因通道數的增多而變得更加難以調整。在這項研究中，我們設計了一種用於HIFU 治療的四通道聚焦式超音波驅動統，包含現場可程式化邏輯閘陣列(FPGA)、高速數模轉換器(DAC)、推挽式的驅動電路以及簡單的阻抗匹配。避免了輸出擁有高次諧波的問題，並且也能產生足夠的聲壓，這項進展為設計用於未來腦部治療的便攜式多通道經顱FUS 系統提供了可能性。另外系統提供Chirp 模式，為治療式超音波提供一種具有潛力的訊號模式。

In recent years, the non-invasive nature and clinical effectiveness of High-Intensity Focused Ultrasound (HIFU) therapy have made it a crucial element in clinical practice, leading to a need for more advanced driving circuits to enhance treatment safety and efficacy. Multi-channel phase-controlled focused ultrasound systems, offering adjustable focal depths and positions, provide greater flexibility over traditional single-channel systems with fixed focal points. However, traditional nonlinear driving circuits often generate higher-order harmonics, creating sidelobe effects and challenges in impedance matching when more channels are added. To address these issues, our study introduces a four-channel focused ultrasound driving system designed for HIFU treatments. It includes a Field-Programmable Gate Array (FPGA), high-speed Digital-to-Analog Converters (DACs), push-pull driving circuits, and a simplified impedance matching approach. This system effectively eliminates higherorder harmonic output while producing adequate acoustic pressure, paving the way for portable, multi-channel transcranial FUS systems suitable for brain treatments. Additionally, it features a Chirp mode, promising for various therapeutic ultrasound applications.