Abstract
Craniotomy using a drill and saw frequently results in fragmentation of the skull plate. Lasers have the potential to remove the skull plate intact. TE CO2 lasers operating at the peak absorption wavelength of bone (λ=9.6 μm) and with pulse durations of 5-10 μs, approximately the thermal relaxation time in hard tissue, produced high ablation rates and minimal peripheral thermal damage. Both thick (2 mm) and thin (250 μm) bovine skull samples were perforated and the ablation rates calculated. Results were compared with Q-switched and free-running Er:YAG lasers (λ=2.94 μm, τp = 150 ns and 150 μs). The CO2 laser perforated thick sections at ablation rates of 10-15 μm per pulse and fluences of approx. 6 J/cm2. There was no discernible thermal damage and no need for water irrigation during ablation. Pulse durations ≥ 20 μs resulted in significant tissue charring which increased with the pulse duration. Although the Er:YAG laser produced ablation rates of approx. 100 μm per pulse, fluences > 30 J/cm2 were required to perforate thick samples, and thermal damage measured 25-40 μm. In summary, the novel 5-10 μs pulse length of the TE CO2 laser is long enough to avoid a marked reduction in the ablation rate due to plasma formation and short enough to avoid peripheral thermal damage through thermal diffusion during the laser pulse. Further studies with the TE CO2 laser are warranted for potential clinical application in craniotomy procedures.
Original language | English (US) |
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Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering |
Publisher | Society of Photo-Optical Instrumentation Engineers |
Pages | 128-130 |
Number of pages | 3 |
Volume | 3914 |
State | Published - 2000 |
Event | Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical - San Jose, CA, USA Duration: Jan 22 2000 → Jan 27 2000 |
Other
Other | Laser-Tissue Interaction XI: Photochemical, Photothermal, and Photomechanical |
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City | San Jose, CA, USA |
Period | 1/22/00 → 1/27/00 |
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics