＂熱＂對人體是很重要的免疫反應啟動機制之一，加上組織細胞本身具不耐熱的特性，所以熱治療被認為是去除有害組織(Tissue Ablation)最有效的方法之一。熱治療主要是利用熱來燒灼組織，當組織受到高溫時會凝固並壞死，而達到去除目的。目前以RFA (Radio Frequency Ablation)射頻燒灼治療和MWA (Microwave Ablation)微波熱療技術最為廣泛使用，但由於專利問題，儀器必須仰賴國外進口，導致此兩種療程的索費甚高，造成患者使用上的負擔。有鑑於此，應用各種加熱原理的熱療儀器開始推陳出新，如外感應加熱熱療，使用大能量的外感應加熱器在體外產生交變磁場，誘發放入組織內的感磁性材料或經皮穿刺到組織的感磁針生熱，達到治療目的。但此技術會衍生諸多問題，如磁力未能深入人體深處、針具製作與材料選用麻煩，以及臨床操作會因高強度磁場而有安全疑慮等問題；亦有應用電阻加熱的原理來設計熱療儀器，傳統的電阻熱療，嵌入電阻導熱基材於燒灼針內，根據電生熱特性使針尖生熱達到治療效果，但常因為導熱基材的尺寸要求，衍生燒灼針直徑過大的情形。
　　本研究針對改善上述熱療技術情形來加以探討，提出一種新的原創熱治療模組設計概念，整合發展出包含燒灼針具、電源供應系統以及監控系統等的一套完整熱治療系統，並以實作證明所提之設計可行性高，功能上也與目前市售系統相當。設計的主要概念為結合內感應和電阻加熱兩種原理來設計加熱端，將直徑極細的漆包線繞於熱電偶上形成感應線圈，外層套上具微感磁性的PTC
穿刺針，插入組織後，將線圈通以高頻電流產生交變磁場，誘發外層管狀針之內壁生熱，加上感應線圈段根據阻抗自成一電阻發熱元件，藉由兩種原理生產之熱能達到組織治療目的。搭配Arduino開發板設計PID模組溫度控制，再輔以電腦人機介面來設定所需溫度以及監控溫度上升情形。
　　考量到頻率對感應加熱的優劣是一重要指標，撰寫頻率自調(Frequency Self-tuning)功能，電源供應系統利用電感值會隨著線圈匝數多寡變化的特性，自動地調整輸出頻率使其接近諧振頻率，如此可確保在加熱線圈段即使長度不同時，皆能擁有最佳的加熱速率，以便適用於治療不同大小的組織。一般而言，當溫度達到攝氏50~70 °C時便可造成組織細胞凝固性壞死。根據離體豬肝燒灼和動物實驗結果，以內部具1~5 cm加熱線圈段之燒灼針實驗，能有效地在動物組織內升溫至所要求溫度，每次加熱最大斷面面積約直徑1~1.5 cm。綜觀以上，此系統的整體效果與市售熱療系統差異不大，但可大幅地降低醫療成本，並且改善傳統外感應與電阻熱療所遭遇問題。往後亦可搭配多針使用來達到較大斷面燒灼，且可開發5 cm以上長型加熱針延伸出新的醫學療程及應用。

Heat can destroy tissue efficiently due to tissue’s low heat-resisting capability. Thus, thermal therapy for tissue ablation is considered to be one of the most effective approaches to ablate harmful tissues from human’s organ via heating. In this thesis, an integrated inner induction heating and resistance heating approach for thermal tissue ablation was proposed. The idea was first verified with finite element analysis and a series of experiments to prove the feasibility of this approach. Then a high frequency power supply system and a needle system was developed, designed and fabricated. The high frequency power system was designed similar to an induction power supply system with maximum power capability of 30 W, maximum current of 2 A and maximum voltage of 30 V. The power supply system also had the capability to detect the resonant frequency of the needle system automatically in order to supply the maximum amount of current to the needle module. The needle module was made with an 18-gauge size PTC needle (1.24 mm outer diameter and 0.96 mm inner diameter, 150 mm long) which is commonly used for medical treatment. The material for the PTC needle is SUS 304 or SUS 316 (low magnetic permeability material) which is a common material used for medical devices. A 0.5 mm in diameter thermocouple with stainless steel sheath was used as the core for enameled wire coil wrapping and also used for temperature detection. The core with the coil was then installed inside of the PTC needle. Arduino microprocessor was used to control heating process. Connect the needling system to the power supply under microprocessor control would form a complete system for thermal therapy. The system was tested via series of vitro pig liver and alive animal experiments to verify its effectiveness and capability. It was found that, with proper setting of voltage in the power supply, the system could efficiently detect and set the system frequency to the resonant frequency, thus heat and ablate the tissue efficiently. From the results, it was found that the diameters of the ablated tissue cross sections were always bigger than 10 mm. The length of the ablating could range from 10 to 50 mm. Thus, the ablating volume could be big. In comparison with current RFA, microwave or laser ablation devices, the proposed novel and innovative system performed equally well or even better. However, the system was compact and the needles used were small. Even the cost of the system was low thus could overcome the high medical cost of thermal ablation. Due to its capability to ablate very high volume of cylindrical shaped tissue with just one needle, this system also has the potential to create new medical treatments for the patients.

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