TODAY’S PATENT – DEVICE FOR MEASURING THE SPEED OF BLOOD IN A BLOOD VESSEL OF THE EYE

Inventd jointly by Martial Henri Geiser, Frédéric Truffer, Helene Strese and Christophe Chiquet and assigned to Universite Grenoble Alpes, the invention was granted patent on 18^th February 2020 and the same was published on 25-10-2018 with the patent no. US20180303338A1.

The invention  pertains to a device designed to measure blood velocity within eye blood vessels using laser Doppler velocimetry (LDV). It addresses challenges faced by a prior LDV system described in U.S. Patent No. 5900928, co-invented by one of the present application’s inventors, which was difficult to adjust due to confocal coupling of optical elements.

The newly proposed LDV device simplifies the LDV measurement process. It comprises a coherent light source (often an infrared laser) that generates a source beam. Two detectors with entrance apertures capture the backscattered light from a blood vessel in the eye. An optical system includes a Dove prism, through which the source beam and backscattered beams pass. This optical system can be adjusted by rotation around an axis parallel to the source beam.

A focusing system ensures that the image of the blood vessel aligns with the entrance apertures. A signal processor processes detector signals. A key innovation involves an optical element that can be introduced during device adjustment. This element transforms the light spot produced by the light source into a coplanar line with the source beam and the selected backscattered beams.

This transformation helps align the device with a specific blood vessel in the eye and ensures the line matches the tangent at the point of illumination on the vessel. This alignment is achieved by rotating the Dove prism. By simplifying the LDV setup and alignment, this invention enhances the usability and efficiency of blood velocity measurements in eye blood vessels. It preserves the functionality of the previous LDV system but offers greater ease of use and adjustment.