Method for detecting coagulation in laser treatment of blood vessels
US6766187B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2000 |
| Grant date | Jul 20, 2004 |
| Priority date | — |
| Expiry date | Nov 24, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2017/00057
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Onset of coagulation of blood in a blood vessel irradiated by electromagnetic radiation is detected by directing light at the blood vessel and monitoring the intensity of a portion of the light remitted from the blood vessel. An increase or decrease in the monitored light intensity indicates the onset of coagulation. The increase or decrease results from the formation of methemoglobin in the blood which accompanies the onset of coagulation. The methemoglobin is formed by photo conversion or thermal conversion of normal blood oxyhemoglobin. The wavelength of the monitoring light is selected to be different from that of the electromagnetic radiation and is preferably a wavelength for which the ratio of its absorptivity in hemoglobin and its absorptivity in normal blood is less than about one-half or greater than about two.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.