Multimodal feedback systems for smart laser osteotomy: Depth control and tissue differentiation

Arsham Hamidi; Yakub A Bayhaqi; Sandra Drusová; Alexander A Navarini; Philippe C Cattin; Ferda Canbaz; Azhar Zam

doi:10.1002/lsm.23732

Multimodal feedback systems for smart laser osteotomy: Depth control and tissue differentiation

Lasers Surg Med. 2023 Dec;55(10):900-911. doi: 10.1002/lsm.23732. Epub 2023 Oct 23.

Authors

Arsham Hamidi¹, Yakub A Bayhaqi¹, Sandra Drusová¹, Alexander A Navarini², Philippe C Cattin³, Ferda Canbaz¹, Azhar Zam^{1

4

5}

Affiliations

¹ Biomedical Laser and Optics Group (BLOG), Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland.
² Digital Dermatology, Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland.
³ Department of Biomedical Engineering, Center for medical Image Analysis and Navigation (CIAN), University of Basel, Allschwil, Switzerland.
⁴ Division of Engineering, New York University Abu Dhabi, Abu Dhabi, UAE.
⁵ Department of Biomedical Engineering, Department of Electrical and Computer Engineering, Tandon School of Engineering, New York University, Brooklyn, New York, USA.

PMID: 37870158
DOI: 10.1002/lsm.23732

Abstract

Objectives: 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.

Materials and methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Er:YAG laser; laser osteotomy; laser-induced breakdown spectroscopy; optical coherence tomography; smart laser surgery.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Feedback
Laser Therapy* / methods
Lasers, Solid-State* / therapeutic use
Light
Osteotomy
Swine