Computer simulations of thermal tissue remodeling during transvaginal and transurethral laser treatment of female stress urinary incontinence.
Computer simulations of thermal tissue remodeling during transvaginal and transurethral laser treatment of female stress urinary incontinence.
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DOI：
10.1002/lsm.22491
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发表时间：
2017-03
影响因子：
2.4
通讯作者：
Fried NM
中科院分区：
文献类型：
--
作者：
Hardy LA;Chang CH;Myers EM;Kennelly MJ;Fried NM
研究了一种非手术治疗女性压力性尿失禁的方法，即用表面组织冷却对皮下组织进行激光热重塑。进行了光传输、热传递和组织热损伤的计算机模拟，比较了经阴道和经尿道入路。蒙特卡罗（MC）模拟提供了吸收光子在组织层（阴道壁、盆腔内筋膜和尿道壁）中的空间分布。在λ=1064 nm处对各组织的光学性质（n,μa,μs,g）进行赋值。在前人实验的基础上，采用直径为5mm的激光束，入射功率为5w，持续时间为15秒。MC输出被转换成吸收的能量，作为组织温度随时间变化的有限元传热模拟的输入。模拟了接触探针冷却温度为0℃时的对流换热。用于热模拟的变量（κ,c,ρ）被分配到每个组织层。采用MATLAB代码进行Arrhenius积分热损伤计算。利用ANSYS输出数据构建温度矩阵，采用有限和法近似计算Arrhenius积分。组织损伤特性（Ea，A）用于计算Arrhenius和。经阴道入路，37%的能量在骨盆内筋膜靶层吸收，0.8%的能量在靶层外沉积。峰值温度71℃，处理区直径0.8 mm，保留2.7 mm厚阴道壁2.4mm。经尿道入路时，18%的能量在盆腔筋膜吸收，0.3%的能量在筋膜外沉积。峰值温度80℃，治疗区直径2.0 mm，保留2.4 mm厚尿道壁0.6 mm。计算机模拟表明经阴道入路比经尿道入路更可行。
A non-surgical method is being developed for treating female stress urinary incontinence by laser thermal remodeling of subsurface tissues with applied surface tissue cooling. Computer simulations of light transport, heat transfer, and thermal damage in tissue were performed, comparing transvaginal and transurethral approaches. Monte Carlo (MC) simulations provided spatial distributions of absorbed photons in the tissue layers (vaginal wall, endopelvic fascia, and urethral wall). Optical properties (n,μa,μs,g) were assigned to each tissue at λ=1064 nm. A 5-mm-diameter laser beam and incident power of 5 W for 15 seconds was used, based on previous experiments. MC output was converted into absorbed energy, serving as input for finite element heat transfer simulations of tissue temperatures over time. Convective heat transfer was simulated with contact probe cooling temperature set at 0°C. Variables used for thermal simulations (κ,c,ρ) were assigned to each tissue layer. MATLAB code was used for Arrhenius integral thermal damage calculations. A temperature matrix was constructed from ANSYS output, and finite sum was incorporated to approximate Arrhenius integral calculations. Tissue damage properties (Ea,A) were used to compute Arrhenius sums. For the transvaginal approach, 37% of energy was absorbed in the endopelvic fascia target layer with 0.8% deposited beyond it. Peak temperature was 71°C, the treatment zone was 0.8-mm-diameter, and 2.4mm of the 2.7-mm-thick vaginal wall was preserved. For transurethral approach, 18% energy was absorbed in endopelvic fascia with 0.3% deposited beyond the layer. Peak temperature was 80°C, treatment zone was 2.0-mm-diameter, and 0.6 mm of 2.4-mm-thick urethral wall was preserved. Computer simulations suggest that transvaginal approach is more feasible than transurethral approach.
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DOI：
10.1016/s0889-8545(05)70048-6
发表时间：
1998-12-01
影响因子：
3.2
作者：
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通讯作者：
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影响因子：
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影响因子：
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作者：
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影响因子：
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DOI：
10.1109/2944.577320
发表时间：
1996-12-01
影响因子：
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作者：
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