Effects of temperature-dependent optical properties on the fluence rate and temperature of biological tissue during low-level laser therapy
Effects of temperature-dependent optical properties on the fluence rate and temperature of biological tissue during low-level laser therapy
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DOI：
10.1007/s10103-013-1376-4
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发表时间：
2014-03-01
影响因子：
2.1
通讯作者：
Jeong, Sungho
中科院分区：
文献类型：
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作者：
Kim, Soogeun;Jeong, Sungho
通过实验和数值方法研究了低强度激光治疗（LLLT）过程中温度依赖性光学特性对生物组织内注量率和温度分布变化的影响。分别使用光纤传感器和热电偶在体外测量猪皮内的注量率和温度，同时用连续波激光（IPG Laser GmbH，Burbach，德国，1,064 nm，3.14 W/cm(2)）照射样品。使用逆加倍算法根据双积分球测量的总反射率和透射率来估计猪皮肤的吸收和减少散射系数。结果表明，随着皮肤温度在 26-40 A 摄氏度范围内升高，猪皮肤的还原散射系数显着降低。为了在模拟中考虑组织光学特性的温度依赖性，建立了采用注量率和生物传热耦合方程的数学模型。结果表明，所提出的数学模型预测的注量率和温度与猪皮肤的测量值非常吻合。使用开发的模型计算人体皮肤温度表明，如果在 LLLT 模拟过程中忽略人体皮肤光学特性的温度依赖性，则可能会严重低估皮肤温度。
The effects of temperature-dependent optical properties on the change of fluence rate and temperature distribution within biological tissues during low-level laser therapy (LLLT) were investigated by experimental and numerical methods. The fluence rate and temperature within a porcine skin were measured in vitro using an optical fiber sensor and a thermocouple, respectively, while irradiating the sample with a continuous wave laser (IPG Laser GmbH, Burbach, Germany, 1,064 nm, 3.14 W/cm(2)). The absorption and reduced scattering coefficients of porcine skin were estimated using an inverse adding-doubling algorithm from the total reflectance and transmittance measured with a double-integrating sphere. It was shown that the reduced scattering coefficient of porcine skin decreased significantly as the skin temperature increased within the range of 26-40 A degrees C. To incorporate the temperature dependency of tissue optical properties in the simulation, a mathematical model that adopted coupled equations for fluence rate and bioheat transfer was developed. It was shown that the predicted fluence rate and temperature by the proposed mathematical model agreed closely with the measured values of porcine skin. The calculation of human skin temperature using the developed model revealed that the skin temperature could be significantly underestimated if the temperature dependency of optical properties of human skin were ignored during LLLT simulation.