Laser safety in fiber-optic monitoring of spinal cord hemodynamics: a preclinical evaluation
Laser safety in fiber-optic monitoring of spinal cord hemodynamics: a preclinical evaluation
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DOI：
10.1117/1.jbo.23.6.065003
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发表时间：
2018-06-01
影响因子：
3.5
通讯作者：
Floyd, Thomas F.
中科院分区：
文献类型：
--
作者：
Busch, David R.;Davis, James;Floyd, Thomas F.
脊髓损伤的预防和治疗主要集中在维持脊髓血流，但目前还没有监测脊髓缺血的技术。我们最近展示了使用光学探针的漫射相关和光谱学对脊髓缺血的连续监测。在这项技术的临床应用之前，证明脊髓暴露在所需光线下的安全性至关重要。据我们所知，这是第一次对这种监测仪进行现场安全测试的报告。在生存手术模型（11只成年多塞特羊）中，我们使用定制的光纤硬膜外探针将脊髓暴露在激光下。我们将仪器的组织照度与美国国家标准协会的最大允许曝光量进行比较。我们通过实验评估了与长时间暴露于激光源有关的辐射羊的神经和病理结果，并评估了离体脊髓样品的加热。脊髓组织暴露在类似于眼睛最大允许暴露量的18倍和类似于皮肤（1/3）倍的光照水平下。多学科检测未发现功能性神经系统后遗症、脊髓激光相关损伤的组织病理学证据或离体样本明显的温度变化。低组织辐照度和长时间暴露于激光源后缺乏神经、病理和温度变化，证明在硬膜外腔内放置近红外光学探头可以安全监测脊髓组织。(C) 2018年中国光学仪器工程师学会（SPIE）
The prevention and treatment of spinal cord injury are focused upon the maintenance of spinal cord blood flow, yet no technology exists to monitor spinal cord ischemia. We recently demonstrated continuous monitoring of spinal cord ischemia with diffuse correlation and optical spectroscopies using an optical probe. Prior to clinical translation of this technology, it is critically important to demonstrate the safety profile of spinal cord exposure to the required light. To our knowledge, this is the first report of in situ safety testing of such a monitor. We expose the spinal cord to laser light utilizing a custom fiber-optic epidural probe in a survival surgery model (11 adult Dorset sheep). We compare the tissue illumination from our instrument with the American National Standards Institute maximum permissible exposures. We experimentally evaluate neurological and pathological outcomes of the irradiated sheep associated with prolonged exposure to the laser source and evaluate heating in ex vivo spinal cord samples. Spinal cord tissue was exposed to light levels at similar to 18x the maximum permissible exposure for the eye and similar to(1/3)x for the skin. Multidisciplinary testing revealed no functional neurological sequelae, histopathologic evidence of laser-related injury to the spinal cord, or significant temperature changes in ex vivo samples. Low tissue irradiance and the lack of neurological, pathological, and temperature changes upon prolonged exposure to the laser source offer evidence that spinal cord tissues can be monitored safely with near-infrared optical probes placed within the epidural space. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)