Holmium laser ablation of cartilage: effects of cavitation bubbles

Thomas Asshauer; Thomas Jansen; Thorsten Oberthur; Guy P. Delacretaz; Bruno E. Gerber

doi:10.1117/12.209905

22 May 1995 Holmium laser ablation of cartilage: effects of cavitation bubbles

Thomas Asshauer, Thomas Jansen, Thorsten Oberthur, Guy P. Delacretaz, Bruno E. Gerber

Proceedings Volume 2391, Laser-Tissue Interaction VI; (1995) https://doi.org/10.1117/12.209905
Event: Photonics West '95, 1995, San Jose, CA, United States

Abstract

The ablation of fresh harvested porcine femur patellar groove cartilage by a 2.12 micrometers Cr:Tm:Ho:YAG laser in clinically used irradiation conditions was studied. Laser pulses were delivered via a 600 micrometers diameter fiber in isotonic saline. Ablation was investigated as a function of the angle of incidence of the delivery fiber with respect to the cartilage surface (0-90 degrees) and of radiant exposure. Laser pulses with energies of 0.5, 1.0 and 1.5 J and a duration of 250 microseconds were used. A constant fiber tip-tissue distance of 1 mm was maintained for all experiments. The dynamics of the induced vapor bubble and of the ablation process was monitored by time resolved flash videography with a 1 microseconds illumination. Acoustic transients were measured with a piezoelectric PVDF needle probe hydrophone. Bubble attachment to the cartilage surface during the collapse phase, leading to the direct exposition of the cartilage surface to the maximal pressure generated, was observed in all investigated irradiation conditions. Maximal pressure transients of up to 200 bars (at 1 mm distance from the collapse center) were measured at the bubble collapse at irradiation angles >= 60 degrees. No significant pressure variation was observed in perpendicular irradiation conditions as a function of radiant exposure. A significant reduction of the induced pressure for irradiation angles

Citation Download Citation

Thomas Asshauer, Thomas Jansen, Thorsten Oberthur, Guy P. Delacretaz, and Bruno E. Gerber "Holmium laser ablation of cartilage: effects of cavitation bubbles", Proc. SPIE 2391, Laser-Tissue Interaction VI, (22 May 1995); https://doi.org/10.1117/12.209905

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available