Title :
Automatic control of lesion size in a simulated model of the eye
Author :
Yang, Youli ; Markow, Michael S. ; Welch, J. ; Rylander, H. Grady, III
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA
fDate :
12/1/1990 12:00:00 AM
Abstract :
A multiple-layer phantom consisting of a thin absorbing layer sandwiched between two nonabsorbing layers was created to simulate laser-induced thermal lesions in the eye. The nonabsorbing layers consisted of clear egg white, and the thin (20-40-μm) absorbing layer was created with black spray paint. Heat generated in the absorbing layer during 0.5-10-s argon irradiation was conducted to the adjacent egg white. Sufficient heat produced a region of coagulation that was graphically evidenced by the characteristic whiteness of cooked egg white. Light reflected from the lesion was monitored with a video camera and used as a feedback signal to control irradiation time. The laser irradiation was automatically ended when the diameter of the reflectance parameter related to coagulation thickness reached a preselected value
Keywords :
biological effects of laser radiation; biothermics; eye; laser applications in medicine; modelling; radiation therapy; automatic control; black spray paint; clear egg white; coagulation; cooked egg white; diameter; eye; feedback signal; irradiation time; laser irradiation; laser-induced thermal lesions; lesion size; multiple-layer phantom; nonabsorbing layers; reflectance parameter; simulated model; thin absorbing layer; video camera; whiteness; Argon; Automatic control; Coagulation; Imaging phantoms; Laser feedback; Laser modes; Lesions; Monitoring; Paints; Spraying;
Journal_Title :
Quantum Electronics, IEEE Journal of
