Hamidi Arsham, Bayhaqi Yakub A, Drusová Sandra, Navarini Alexander A, Cattin Philippe C, Canbaz Ferda, Zam Azhar
Biomedical Laser and Optics Group (BLOG), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland.
Digital Dermatology, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland.
Lasers Surg Med. 2023 Dec;55(10):900-911. doi: 10.1002/lsm.23732. Epub 2023 Oct 23.
The study aimed to improve the safety and accuracy of laser osteotomy (bone surgery) by integrating optical feedback systems with an Er:YAG laser. Optical feedback consists of a real-time visual feedback system that monitors and controls the depth of laser-induced cuts and a tissue sensor differentiating tissue types based on their chemical composition. The developed multimodal feedback systems demonstrated the potential to enhance the safety and accuracy of laser surgery.
The proposed method utilizes a laser-induced breakdown spectroscopy (LIBS) system and long-range Bessel-like beam optical coherence tomography (OCT) for tissue-specific laser surgery. The LIBS system detects tissue types by analyzing the plasma generated on the tissue by a nanosecond Nd:YAG laser, while OCT provides real-time monitoring and control of the laser-induced cut depth. The OCT system operates at a wavelength of 1288 ± 30 nm and has an A-scan rate of 104.17 kHz, enabling accurate depth control. Optical shutters are used to facilitate the integration of these multimodal feedback systems.
The proposed system was tested on five specimens of pig femur bone to evaluate its functionality. Tissue differentiation and visual depth feedback were used to achieve high precision both on the surface and in-depth. The results showed successful real-time tissue differentiation and visualization without any visible thermal damage or carbonization. The accuracy of the tissue differentiation was evaluated, with a mean absolute error of 330.4 μm and a standard deviation of ±248.9 μm, indicating that bone ablation was typically stopped before reaching the bone marrow. The depth control of the laser cut had a mean accuracy of 65.9 μm with a standard deviation of ±45 μm, demonstrating the system's ability to achieve the pre-planned cutting depth.
The integrated approach of combining an ablative laser, visual feedback (OCT), and tissue sensor (LIBS) has significant potential for enhancing minimally invasive surgery and warrants further investigation and development.
本研究旨在通过将光学反馈系统与铒钇铝石榴石（Er:YAG）激光相结合，提高激光截骨术（骨手术）的安全性和准确性。光学反馈包括一个实时视觉反馈系统，用于监测和控制激光切割的深度，以及一个基于化学成分区分组织类型的组织传感器。所开发的多模态反馈系统显示出提高激光手术安全性和准确性的潜力。
所提出的方法利用激光诱导击穿光谱（LIBS）系统和用于组织特异性激光手术的远程类贝塞尔光束光学相干断层扫描（OCT）。LIBS系统通过分析纳秒钕钇铝石榴石（Nd:YAG）激光在组织上产生的等离子体来检测组织类型，而OCT提供对激光切割深度的实时监测和控制。OCT系统在1288 ± 30 nm的波长下运行，A扫描速率为104.17 kHz，能够实现精确的深度控制。使用光学快门来促进这些多模态反馈系统的集成。
在所提出的系统在五个猪股骨标本上进行了测试，以评估其功能。利用组织分化和视觉深度反馈在表面和深度上均实现了高精度。结果显示成功实现了实时组织分化和可视化，且无任何可见的热损伤或碳化。评估了组织分化的准确性，平均绝对误差为330.4 μm，标准差为±248.9 μm，表明在到达骨髓之前通常会停止骨消融。激光切割的深度控制平均精度为65.9 μm，标准差为±45 μm，证明了该系统实现预先计划切割深度的能力。
将消融激光、视觉反馈（OCT）和组织传感器（LIBS）相结合的综合方法在增强微创手术方面具有巨大潜力，值得进一步研究和开发。
