Osipyan Institute of Solid State Physics of the Russian Academy of Sciences, Chernogolovka 142432, Russia.
Prokhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia.
Sensors (Basel). 2024 Jun 5;24(11):3655. doi: 10.3390/s24113655.
This work describes a sapphire cryo-applicator with the ability to sense tissue freezing depth during cryosurgery by illumination of tissue and analyzing diffuse optical signals in a steady-state regime. The applicator was manufactured by the crystal growth technique and has several spatially resolved internal channels for accommodating optical fibers. The method of reconstructing freezing depth proposed in this work requires one illumination and two detection channels. The analysis of the detected intensities yields the estimation of the time evolution of the effective attenuation coefficient, which is compared with the theoretically calculated values obtained for a number of combinations of tissue parameters. The experimental test of the proposed applicator and approach for freezing depth reconstruction was performed using gelatin-based tissue phantom and rat liver tissue in vivo. It revealed the ability to estimate depth up to 8 mm. The in vivo study confirmed the feasibility of the applicator to sense the freezing depth of living tissues despite the possible diversity of their optical parameters. The results justify the potential of the described design of a sapphire instrument for cryosurgery.
这项工作描述了一种蓝宝石低温冷冻应用器，它能够通过对组织进行照明并在稳态下分析漫射光信号来感知冷冻手术过程中组织的冷冻深度。该应用器是通过晶体生长技术制造的，具有几个空间上分开的内部通道，用于容纳光纤。这项工作中提出的重建冷冻深度的方法需要一个照明和两个检测通道。对检测到的强度进行分析可以得到有效衰减系数的时间演化估计值，该值与针对组织参数的许多组合计算得到的理论值进行比较。使用基于明胶的组织体模和大鼠肝组织在体进行了对所提出的冷冻深度重建应用器和方法的实验测试。结果表明，该方法能够估计深度达 8 毫米。体内研究证实了该应用器能够感知活体组织的冷冻深度，尽管它们的光学参数可能存在差异。这些结果证明了所描述的蓝宝石仪器设计用于冷冻手术的潜力。
