Spectrum diagnosis and temperature monitoring of femtosecond laser laminectomy

Orthopedic diseases are increasingly becoming a prominent problem threatening human health. Traditional mechanical osteotomy causes mechanical and thermal damages, which are believed to increase the safety risk of orthopedic surgery. Femtosecond lasers provide a safe and efficient method for laminectomy. In this study, the experiments were conducted on femtosecond laser ablation operations aided by convolutional neural network and collaborative control. The various spectra during femtosecond laser bone ablation were detected by using isolated porcine ribs. An optical fiber spectrometer was used to monitor the spectrum, which was proved to reflect the laser ablation process. The spectral composition during femtosecond laser bone ablation was analyzed. The second harmonic was related to the penetration. The temperature distribution indicated that 15 W with cooling was the best parameter for preventing carbonization. Defocusing the laser improved safety because the ablated effect was very limited when the defocus distance was 4 mm. Although large energy input resulted in better efficiency, it also caused carbonization due to overheating.