不同水流速度對假體內熱治療溫度分布之研究

目的：探討深部熱治療時，水流流速對假體內熱分布之影響。材料與方法：利用電容板式電極加熱治療系統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。第一部份先利用電磁功率400瓦、直徑大小相同(20公分)的電極對假體施熱，並量測其縱向和橫向的溫度分布。第二部份則另加一水管貫穿肌肉假體的中心位置，以循環液流過以模擬血液流動狀態，分別以不同的水流速度(9.45, 18.9, 75.15和150.3ml/min)來討論其中央縱向溫度分布狀態。結果：第一部份的實驗結果顯示，由中央縱向溫度分佈狀態顯示溫度從中心點向外遞減，但是靠近兩電容板電極處皆有過熱現象，且假體下方之溫度較上方高5-6℃左右；而中央橫向溫度分布狀態則顯示靠近熱治療加熱電極的一側溫度比對側端高3-4℃左右。第二部份研究顯示：水流速度愈快，熱傳導速度增加，能量流失百分比也增加，故溫度比較低。但是當水流速度增至150.3ml/min，能量流失反而成穩定狀態，溫度變化不明顯。結論：當假體內加入水流的因素後，水流流速的大小確能影響熱分布的狀況,使溫度降低。但當水流速度增至150.3ml/min，能量流失反而成穩定狀態，溫度變化不明顯。

關鍵字

射頻；熱分布

並列摘要

Purpose: To evaluate the effects of velocity of water flow on temperature distribution in a phantom. Material and Method: The beating device is the 13.56 MHz radiofrequency capacitive hyperthermia system. A phantom with flow is designed, namely, one silicone tube inserted into a homogenous muscle phantom. The temperature to be achieved is 43℃. It was measured by thin- coated thermocouples which are inserted into phantom through angiocatheter. The catheters were arranged with the aid of self-design holder. Simutaneously, thermogram was done via the computerized system. We compare the thermal distribuation in two different enviorments: 1. Phantom without flow as a control arm, 2. Phantom with single silicone tube. The flow rates of water through silicone tubes are controlled by a microtube pump. Result: The control arm demonstrated there was a tendency that the temperature of upper part of the phantom was lower than lower part. In experimental group, progressively increased velocity of the flow will also increase the ability of heat conduction. This phenomenon was not observed when the flow rate reached 150.3 ml/mm. Conclusion: Water flow played an important role in thermal distribution. The higher the velocity of the flow, the more increased ability of heat conduction was noted.

並列關鍵字

Radiofrequency ； Thermal distribution

國際替代計量

不同水流速度對假體內熱治療溫度分布之研究

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