热作用致良性前列腺增生组织的光学特性变化

研究了热作用下的良性前列腺增生(BPH)组织对808和980 nm的半导体激光的光学特性的变化及其差异。实验采用双积分球测量系统以及反向倍增法获取良性前列腺增生组织的光学特性。结果表明,热作用下的良性前列腺增生组织对808 nm和980 nm的吸收系数、约化散射系数和光学穿透深度都是随着加热温度的变化而变化的,在20~80℃的温度范围内,良性前列腺增生组织对808 nm的吸收系数和约化散射系数都分别明显地较其对980 nm的吸收系数和约化散射系数要大,而其对808 nm的光学穿透深度却明显地较其对980 nm的光学穿透深度要小,吸收系数的最大值都在20℃,分别为0.528 mm-1和0.448 mm-1;最小值分别在50℃和70℃,分别为0.436 mm-1和0.326 mm-1,吸收系数的最大差异在70℃,其值为34.1%;约化散射系数的最大值都在80℃,其值分别为1.45 mm-1和1.43 mm-1,最小值分别在20℃和70℃,分别为1.15 mm-1和0.973 mm-1,最大差异在70℃,其值为24.4%;光学穿透深度的最大值分别在50℃和70℃,其值分别为0.684 mm和0.887 mm,最小值都在80℃,其值分别为0.608 mm和0.696 mm,最大差异在70℃,其值为30.4%。在70℃的热作用下良性前列腺增生组织达到完全热凝固,吸收系数、散射系数和光学穿透深度的差异达到最大值。

Thermal Changes on Optical Properties in Human Benign Prostatic Hyperplasia Tissue

Thermal changes and their differences on the optical properties of human benign prostatic hyperplasia (BPH) tissues at 808 nm- and 980 nm-diode laser were study in vitro. The measurements were performed using a double-integrating-sphere setup, and the optical properties of BPH tissue were assessed from these measurements using the inverse adding-doubling method. The results of measurement showed that the absorption coefficients, reduced scattering coefficients and optical penetration depths of BPH tissues at 808 nm and 980 nm varied with a change of exposure temperature by thermal effect. In temperature range from 20 ℃ to 80 ℃, the absorption and reduced scattering coefficients of BPH tissue at 808 nm were obviously bigger than that those of BPH tissue at 980 nm, respectively, and the optical penetration depths of BPH tissue at 808 nm were obviously smaller than those of BPH tissue at 980 nm. Maximal absorption coefficients of BPH tissue at 808 nm and 980 nm were respectively 0.528 mm-1 and 0.448 mm-1 at exposure temperature of 20 ℃, and minimal absorption coefficients were respectively 0.436 mm-1 and 0.326 mm-1 at exposure temperature of 50 ℃ and 70 ℃, respectively, maximal difference in the absorption coefficients between 808 nm and 980 nm was 34.1% at exposure temperature of 70 ℃. Maximal reduced scattering coefficients of BPH tissue at 808 nm and 980 nm were respectively 1.45 mm-1 and 1.43 mm-1 at exposure temperature of 80 ℃, and minimal reduced scattering coefficients were respectively 1.15 mm-1 and 0.973 mm-1 at exposure temperature of 20 ℃ and 70 ℃, respectively, maximal difference in the reduced scattering coefficients between 808 nm and 980 nm was 24.4% at exposure temperature of 70 ℃. Maximal optical penetration depths of BPH tissue at 808 nm and 980 nm were respectively 0.684 mm and 0.887 mm at exposure temperature of 50 ℃ and 70 ℃, and minimal optical penetration depths were respectively 0.608 nm and 0.696 mm at 80 ℃, respectively, maximal difference in the optical penetration depths between 808 nm and 980 nm was 30.4% at exposure temperature of 70 ℃. BPH tissues arrived at complete coagulation by heat effect at exposure temperature of 70 ℃, at this point, the differences in the absorption coefficients, reduced scattering coefficients and optical penetration depths between 808 nm and 980 nm were maximal.