Development of a smart holmium:YAG laser lithotriptor.
OBJECTIVE
The purpose of this study was to develop a feedback control system for the pulsed holmium:YAG medical laser that enhances tissue selectivity and safety by discriminating between soft and hard biological tissue such as urinary and biliary calculi and bone.


METHODS
The ability to discriminate is achieved by monitoring prompt laser-induced visible/NIR photoemissions via retrograde transmission over the laser delivery fiber in conjunction with a developed detection algorithm.


RESULTS
Experimental data are presented for a system that employs this discrimination scheme with an electro-optic shutter for rapid intrapulse feedback control of holmium laser-based lithotripsy procedures. The results demonstrate the feasibility of a lithotriptor that can deliver 1 J per pulse to calculi yet limit errant discharges to surrounding urinary tract tissue to < or = 0.1 J.


CONCLUSIONS
Based on animal tissue safety data, the laser margin of safety is improved by an order of magnitude.
Goldey
C L
CL
Physical Sciences Inc., Andover, MA 01810, USA.
Rosen
D I
DI
Hayes
G B
GB
Willscher
M K
MK
Roth
R A
RA
D000465:Algorithms; D000818:Animals; D004867:Equipment Design; D005240:Feasibility Studies; D005246:Feedback; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D017602:Lithotripsy, Laser / Q000295:instrumentation* / Q000379:methods; D011817:Rabbits