Spectroscopic Diagnosis for Control of Laser Treatment of Atherosclerosis

Healthy artery tissue is composed of three layers: intima, media, and adventitia. With the onset of atherosclerosis, fatty and fibrous deposits build up in the intimai layer, narrowing the lumen for blood flow, leading to stroke and heart attack. Laser radiation of modest power can vaporize these deposits, restoring normal flow [l]. This can be accomplished without open heart surgery, using a catheter containing optical fibers to deliver the laser light to the obstruction. However, without appropriate control, arterial perforation can occur. As part of our efforts in this area [2, 3], we are developing a spectroscopic guidance system to diagnose the presence and control the removal of atherosclerotic blockages.