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Proceedings Paper

Visualization of microsecond laser ablation of porcine clot and gelatin under a clear liquid
Author(s): Ujwal S. Sathyam; Alan Shearin; Scott A. Prahl
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Paper Abstract

Laser thrombolysis uses microsecond laser pulses to remove thrombus-blocked arteries in the heart and the brain. Rapidly expanding and collapsing vapor bubbles are formed upon absorption of the laser energy by the thrombus. The goal of this study was to visualize the process of ablation and assess the effects of pulse repetition rate. The differences between contact versus non-contact of the laser delivery device with the thrombus were also investigated. Initial experiments were conducted with a gel-based clot model confined in 3 mm inner diameter silicone tubes. Subsequent experiments used 24 hour old porcine blood clots. Laser pulses of 50 mJ pulse energy were delivered via a quartz fiber contained in a flushing catheter. Pulse repetition rates of 1 Hz, 3 Hz, and 6 Hz were used. Wavelengths of 506 nm and 577 nm were used to ablate clot. Bubble action was captured by flash photography using a CCD camera and recorded on video. The amount of material removed was measured using a spectrophotometric technique. Bubble action was similar on clot and the clot model. No significant differences in bubble action or mass removal were observed at the three pulse repetition rates and the two wavelengths. Contact between the catheter and the clot did not result in a pistoning effect of the catheter at the pulse energy used.

Paper Details

Date Published: 17 May 1996
PDF: 8 pages
Proc. SPIE 2671, Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems VI, (17 May 1996); doi: 10.1117/12.240020
Show Author Affiliations
Ujwal S. Sathyam, Oregon Graduate Institute and Oregon Medical Laser Ctr. (United States)
Alan Shearin, Oregon Medical Laser Ctr. and Palomar Medical Technologies, Inc. (United States)
Scott A. Prahl, Oregon Graduate Institute and Oregon Medical Laser Ctr. (United States)

Published in SPIE Proceedings Vol. 2671:
Lasers in Surgery: Advanced Characterization, Therapeutics, and Systems VI
C. Thomas Vangsness M.D.; Kenneth Eugene Bartels D.V.M.; Lawrence S. Bass M.D.; Graham M. Watson M.D.; R. Rox Anderson M.D.; R. Rox Anderson M.D.; Royice B. Everett; Douglas E. Ott M.D.; Reza S. Malek M.D.; Rodney A. White M.D.; Lloyd P. Tate V.D.M.; Aaron P. Perlmutter M.D., Editor(s)

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