冷冻组织射频比吸收率规律的研究

Study of Specific Absorption Rate of Radiofrequency in Frozen Tissue

为了解决冷冻治疗后冰冻区域吸收RF能力显著减少这一难点,该文研究了低温条件下冷冻组织对射频能量吸收(Specific Absorption Rate,SAR)和其电导率的特点。同时采用提高冷冻组织盐离子浓度的方法来增加其对射频吸收的能力。实验结果显示,同一浓度的冰冻生物组织吸收RF的能力和电导率随温度上升而增加,且增速也随之上升。SAR和电导率随盐离子浓度的增加而近似线性增加。研究结果显示,增加冰冻组织盐离子浓度而增加其电导率的方法可以增强冷冻组织对射频的吸收能力。

In order to increase the heating rate of frozen tissue,we studied the rules of Specific Absorption Rate （SAR） of the frozen tissue to RF and rules of electrical conductivity in the frozen tissue and attempted to en- hance them by increase NaC1 concentration. The results have shown that with increasing of the temperature, both the electrical conductivity of frozen tissue and its increasing rate grows with correspondently more SAR of the RF energy and its increasing rate. Also, it is found that NaC1 concentration had a significant influence on the SAR and electrical conductivity of frozen tissue for the 460 KHz RF used. Correspondingly the electrical conductivity is found to increase linearly with salt concentration. It suggests that injection of NaC1 solution to the targeted tissue before the alternated cooling and heating treatment shall be able to shorten the treatment duration by increasing the adsorption ability of the frozen tissue.