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

Volume

26

Issue

12

fYear

1990

fDate

12/1/1990 12:00:00 AM

Firstpage

2232

Lastpage

2239

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;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/3.64360

Filename

64360