Development of automatic impedance matching system for hyperthermia treatment using resonant cavity applicator
| Autor: | Kazuo Kato, T. Yabuhara, T. Hirashima, Yasuhiro Shindo |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Engineering
Acoustics Impedance matching Imaging phantom law.invention Automation Software Computer Systems law Control theory Electronic engineering Humans Internet Brain Neoplasms Computers Phantoms Imaging business.industry Temperature Hyperthermia Treatment Signal Processing Computer-Assisted Equipment Design Hyperthermia Induced Power (physics) Agar Capacitor Thermodynamics Development (differential geometry) business Algorithms |
| Zdroj: | 2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. |
| DOI: | 10.1109/iembs.2008.4650180 |
| Popis: | In this paper, we discuss a new system to make impedance matching automatically for a re-entrant resonant cavity applicator for brain tumor hyperthermia treatment non-invasively. We have already discussed about the effectiveness of the heating method using manual type impedance matching controller, with experiments of heating an agar phantom and computer simulations. However, it becomes difficult to perform an accurate impedance matching as resonant frequency becomes high. Here, in order to make a more accurate impedance matching, we developed the automatic impedance matching system (AIMS). We noticed that the reflected power was generated when the impedance matching was not complete. In this system, therefore, to reduce the reflected power fed back, the stepping motor to turn the dial of variable capacitors is controlled by developed software. To evaluate the developed AIMS, the experiments of heating the agar phantom were performed. From these results, we found that the temperature rise of the agar phantom by using AIMS was about 180% of using manual type controller under the same heating condition. It was found that the proposed system was very effective for hyperthermia treatment using resonant cavity applicator even when the resonant frequency was high. |
| Databáze: | OpenAIRE |
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