Development of Cancer Treatment System by Induction Heating

- 设备开发为了扩大癌症治疗的最大范围，我们改进了第一个原型设备（可以在距离感应线圈40 mm处产生3 mT的磁场）。通过将输出功率增加到10 kW，谐振电流增加到300 A，线圈直径增加到30 cm，我们已经能够在约90 mm处实现3 mT，这是通过实际测量改进设备的感应磁场强度得到证实的。（a）使用高导磁率材料（铁氧体）通过在线圈下放置铁氧体板，治疗范围进一步扩大到120 mm。从电磁模拟中，我们还证实了这种铁氧体板减少了从施加器泄漏的电磁波。（B）使用“高频电阻“低的“利兹线”由于线圈线的“高频电阻”高， ...更多信息 es.利用“利兹线”的低“高频电阻”，我们将设备的功耗降低了约30%。为了阐明右旋糖酐磁铁矿（DM）的加热机理，我们通过将DM溶液填充到环形管中来测量其“磁滞损耗”。结果，我们发现滞后损失约占DM加热总量的40%。冷却血液流动的模拟由于血液流动，加热区域的冷却机制已经通过一维热传导模拟进行了检查。减少涡流在使用猪等大型动物的试验中，有必要减少对正常细胞的“涡流加热”。通过假设一个简单的模型，我们在理论上发现，即使当DM被充分加热时，通过将设备的输出频率调节为约150 kHz，也可以减少涡流加热。与感应加热相关的其他EMC测量技术已经开发出来。少

-Device developmentIn order to extend the maximum range for cancer treatment, we have improved the first prototype device (which could generate the magnetic field of 3 mT at 40 mm from the induction coil). By increasing the output power to 10kW, the resonance current to 300 A, and the coil diameter to 30 cm, we have been able to realize 3 mT at about 90 mm, which was confirmed by the actual measurement of induced magnetic field strength from the improved device.-Highly effective applicator(a)Use of a high magnetic permeability material (ferrite)The range of the treatment has been further extended to 120 mm, by placing a ferrite board under the coil. From an electromagnetic simulation, we have also confirmed that this ferrite board reduces the electromagnetic waves leaking from the applicator.(b)Use of "litz wire" with low "high-frequency resistance"The copper loss of the applicator on a previous device was as high as 5 kW, because of the high "high-frequency resistance" of the coil wir … More es. Making use of the low "high-frequency resistance" of "litz wire," we have reduced the power consumption of the device by approximately 30%.-DM heating mechanismsIn order to clarify the heating mechanism of Dextran Magnetite (DM), we have measured its "hysteresis loss" by filling the DM solution into a toroidal tube. As a result, we have found that the hysteresis loss occupies about 40 percent of the total amount of DM heating.-Simulation of cooling blood flowThe cooling mechanism of the heated regions due to the blood flow has been examined by a one-dimensional heat conduction simulation.-Eddy current reductionIn the tests using large animals such as pigs, it is necessary to reduce the "eddy current heating" on normal cells. By assuming a simple model, we have found theoretically that the eddy current heating can be reduced even when the DM is sufficiently heated, by adjusting the output frequency of the device as approximately 150 kHz.-Other EMC measurement techniques have been developed associated with the induction heating. Less