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Description
Microwave surgical energy devices are used for hemostasis and anastomosis in modern surgery. Conventional microwave energy devices use coaxial cables for microwave transmission and radiation. However, with this device structure, the heating region may be elongated and distributed on the surface of biological tissue, which may unnecessarily heat healthy tissue. Therefore, it was considered possible to suppress the spread of the heating region by radiating microwaves directly onto the tissue with the end face of the waveguide. The cross-sectional size of the waveguide is related to the frequency of the radio waves propagating inside it, so it is not possible to simply design a smaller size. In order to propagate microwaves at 2.45 GHz, the operating frequency of the device, the cross section must be 100 × 50 mm2, which is obviously not suitable for surgical applications. Therefore, in this study, the operating frequency is set at 5.8 GHz, which is the ISM frequency, and the wavelength is shortened. In addition, the waveguide is filled with a dielectric material to reduce the cross-sectional size of the waveguide due to the wavelength shortening effect. In this study, we investigated microwave transmission in a waveguide filled with dielectric material and heating characteristics when the waveguide is in contact with biological tissue and microwaves are radiated. Numerical calculation and experiment have confirmed that the proposed device can generate a heating region at the center of the phantom surface.
