Infrared laser catheter system
US4917084A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 10, 1988 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Mar 10, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2018/2065
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Laser energy produced by a laser operating in the mid-infrared region (approximately 2 micrometers) is delivered by an optical fiber in a catheter to a surgical site for biological tissue removal and repair. Disclosed laser sources which have an output wavelength in this region include: Holmium-doped Yttrium Aluminum Garnet (Ho:YAG), Holmium-doped Yttrium Lithium Fluoride (Ho:YLF), Holmium-doped Yttrium-Scandium-Gadolinium=Garnet (HO:YSGG), Erbium-doped YAG, Erbium-doped YLF and Thulium-doped YAG. Laser output energy is applied to a silica-based optical fiber which has been specially purified to reduce the hydroxyl-ion concentration to a low level. The catheter may be comprised of a single optical fiber or a plurality of optical fibers arranged to give overlapping output patterns for large area coverage. In a preferred application for the removal of atheroscleotic plaque, a Holmium-doped laser operating in the wavelength range of from about 1.9 to about 2.1 micrometers is preferred. For removal of such plaque by a Holmium-doped laser, it has been found that the threshold energy density should be greater than about 0.6 joules/mm.sup.2 per pulse, and that the pulse width should be su…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.