US 2014/0276088 A1 · Illumination Optics for a Visible or Infrared Based Apparatus and Methods for Viewing or Imaging Blood Vessels

Abstract

The illumination apparatus and methods described herein increase the depth of the illumination's tissue penetration, help minimize surface reflections and back-scatter for a non-contact camera based imaging system thus providing increased tissue-structure contrast and more information about the structures beneath the surface. It does this by using one or more of the following techniques: using optics to provide radiation which hits the surface at or near 90 degrees for better tissue penetration; using optics and radiation source placement to control the angular distribution of light from surface vertical to minimize surface specular reflection and subsurface reflection; removing some surface light reflection through patterning the intensity of the light source thus increasing contrast in areas of no or low direct irradiation; synchronously with respect to camera frames or through user selection, switching on and off light sources which has the effect of 1) dynamically changing the overall angular distribution of light thus changing surface level reflectance; 2) revealing and through processing removing unwanted patterning caused by optical defects or contaminants on optical surfaces or surface hair; 3) moving illumination patterns to permit contrast enhancement in all areas of the surface.

Claims20

Dependent claims

A non-contact illumination apparatus designed to be used in conjunction with a camera, display, and computing element(s) to reveal features such as veins based upon differential wavelength absorption beneath a biological surface being imaged whose underlying substrate, tissue, is a light scattering media, said illumination system comprising:

common optical focusing means, the same size as or larger than the surface to be illuminated;
an extended source means with its own optics such that the radiation from the source means fills or overfills the common optical focusing element;
where the source means is placed approximately at the optical focus of the common optical focusing means wherein the light exiting the common optical focusing means from any one point of the extended source is essentially parallel;
where the beam exiting the common optical focusing means is roughly perpendicular to the surface being illuminated;
where the plurality of all of the extended source means points exiting from the common optical focusing means form a common beam with controlled angular dispersion at the desired distance from the common optical focusing means wherein the beam meets the dual objectives of minimizing the scattering within the tissue by being roughly perpendicular to tissue layers and minimizing specular reflection from the surface of the tissue-structure by hitting the surface at multiple angles.

2 more elements

Dependencies are inferred from the claim text.

Illumination Optics for a Visible or Infrared Based Apparatus and Methods for Viewing or Imaging Blood Vessels

Life of this patent

Illumination Optics for a Visible or Infrared Based Apparatus and Methods for Viewing or Imaging Blood Vessels

Life of this patent

Abstract

Claims20