組織挿植式微波天線陣列熱療系統之假體研究

目的：在探討使用組織挿植式微波熱療系統於假體內溫度分佈之狀況，以評估該系統之發展。材料與方法：本研究乃採用一種新設計的微波天線-套管式同軸狹縫天線來做為實驗中的加熱源，並利用六根天線所組成的天線陣列，以期能於陣列所涵蓋之範圍內作區域性加熱。假體的實驗分兩部分完成，第一部份在不考慮血液循環對於溫度分佈所產生的影響下，利用組織挿植式微波熱治療系統先針對人體均質假體進行加熱。為了能夠測得假體中不同深度的溫度分佈情形，因此於加熱一段時間且假體之溫度分佈到達穩態後，即開始以每次5mm的距離調整溫度計挿入之深度，以量測多個深度平面的溫度分佈結果。第二部份，則利用相同的熱治療系統並配合自行設計的模擬血液循環系統，對肌肉假體進行加熱試驗，與第一部份不同的是另加一水管貫穿肌肉假體的中心位置，藉水溫36℃的循環液流過以模擬血液流動狀態，並分別以五種不同水流速度（25、50、75、100和125ml/min）來討論其溫度分佈狀態。結果：第一部份的實驗結果顯示此一天線陣列加熱時在天線方向上所產生的溫度分佈情形，其最高溫度是出現於接近天線前端之狹縫區域，同時在天線頂端處亦能達劉有效的治療溫度43℃。第二部份研究則顯示在有水流的狀態下，其溫度上升之斜率明顯低於無水流的狀態，因而證實血流對於假體在加熱時其能量的吸收確實有所影響，而且隨著水流流速的增大，其影響亦呈現逐漸增加的趨勢，但是當水流流速到達一定程度時(100ml/min)，水流對於能量之影響將呈現一穩定狀態，此時假體的能量流失率不再隨著水流流速的增加而增加。結論：在本系統溫度監控軟體的自動控制下，對於目前考慮血流的假體實驗設計而言，利用此一熱療系統來進行加熱，將可使整個天線陣列所圍成的區域其溫度分佈維持於43-45℃，而此一實驗結果將有助於未來動物實驗的推展。

關鍵字

微波天線陣列；溫度分佈；假體；穩態；水流流速

並列摘要

Purpose: To test the performance of interstitial microwave antenna array hyperthermia system using a phantom model with or without flow effect Material and Method: The heating device was a custom-made interstitial microwave antenna array hyperthermia system. Six 2450-MHz antennas which were implanted on the corners of a hexagon with intercather spacing of 15 mm were used in this system. A phantom with flow was designed, namely, one silicone tube inserted into a homogenons muscle phantom. The temperature data from four fibrooptic thermometers were fed to the personal computer which could record and analyze the data, also could control the output power of microwave source. To test the system performance, we devided the study into two stages. In the first stage, the thermal distribution in a phantom without flow was conducted. In the second stage, the experiments in a phantom with different flow rates (25, 50, 75, 100 and 125 ml/min) were designed. The flow rates of water through silicone tubes were controlled by a microtube pump. Result: Using the automatic temperature and power control in this interstitial microwave antenna array hyperthermia system, the temperature distribution in phantom can be maintained uniformly in the range of 43-45 DC. The first-stage study showed that there was a tendency that the temperature was concentrated around the antennas. For the flow effect on thermal distribution, the results demonstrated that the faster flow rate would take more energy away in the transient period. However, the rate of energy loss caused by flowing water became constant when the flow rate was faster than l00ml/min. Conclusions: An interstitial microwave antenna array hyperthermia system for deep-seated heating was developed. The superior ability of this system in maintaining uniform temperature distribution around the heating area was also clearly demonstrated.

並列關鍵字

Microwave antenna array ； Temperature distribution ； Phantom ； Steady state ； Flow rate

國際替代計量

組織挿植式微波天線陣列熱療系統之假體研究

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