George C. LaVerde and Brett A. Hooper
Center for Emerging Cardiovascular Technologies, Department of Biomedical Engineering, Duke University
Removing atherosclerotic material without transecting the vessel wall is a common problem for vascular surgeons and interventional cardiologists. The goal of this project is to design and construct a device that uses evanescent optical waves for precise, controlled laser ablation. For laser light incident at an angle to the optic-tissue interface greater than or equal to the critical angle, an evanescent optical wave is launched into the tissue. With evanescent optical waves, there is no free-beam propagation and the laser energy can be confined to a layer less than one wavelength thick at the optic-tissue interface. Several different device designs have been proposed and constructed. The Duke University Mark III IR Free Electron Laser was used to study energy deposition and ablation mechanisms at sapphire-tissue and zinc sulfide-tissue interfaces. Ablation experiments on human low-density-lipoprotein and various cardiovascular tissues will be presented.
