Optical scanning device

Abstract

A device for scanning a body orifice or surface including a light source and a wide angle lens. The light from the light source is projected in a pattern distal or adjacent to the wide angle lens. Preferably, the pattern is within a focal surface of the wide angle lens. The pattern intersects a surface of the body orifice, such as an ear canal, and defines a partial lateral portion of the pattern extending along the surface. A processor is configured to receive an image of the lateral portion from the wide angle lens and determine a position of the lateral portion in a coordinate system using a known focal surface of the wide angle lens. Multiple lateral portions are reconstructed by the processor to build a three-dimensional shape. This three-dimensional shape may be used for purposes such as diagnostic, navigation, or custom-fitting of medical devices, such as hearing aids.

What is claimed is: 
     
         1 . Apparatus for scanning a three dimensional (‘3D’) object, the apparatus comprising:
 a scanner body having mounted upon it a scanning probe, the scanning probe comprising a laser light source, a laser optical element, a source of non-laser video illumination, a wide-angle lens optically coupled to an image sensor, and an image sensor mounted within the scanner body and coupled for data communications to a data processor; 
 a plurality of tracking illumination sensors, the tracking illumination sensors sensing reflections of tracking illumination emitted from a tracking illumination emitter and reflected from tracking fiducials installed at positions that are fixed relative to the scanned object, the tracking illumination sensors also sensing reflections of tracking illumination emitted from the tracking illumination emitter and reflected from tracking targets installed at fixed positions on the scanner body; and 
 the data processor configured so that it functions by constructing, in dependence upon a sequence of images captured when a scanned object is illuminated by laser light and tracked positions of the scanner probe inferred from reflections of tracking illumination sensed by the tracking illumination sensors, a 3D image of the scanned object. 
 
     
     
         2 . The apparatus of  claim 1  further comprising a display screen coupled for data communications to the image sensor, the display screen displaying images of the scanned object. 
     
     
         3 . The apparatus of  claim 2  wherein the display screen displaying images of the scanned object further comprises the display screen displaying video images from the image sensor of the scanned object illuminated only by non-laser video illumination. 
     
     
         4 . The apparatus of  claim 2  wherein the display screen displaying images of the scanned object further comprises the display screen displaying the 3D image of the scanned object. 
     
     
         5 . The apparatus of  claim 1  further comprising a display screen coupled for data communications to the image sensor, the display screen displaying images of the scanned object, the display screen mounted on the scanner body. 
     
     
         6 . The apparatus of  claim 1  wherein the laser light source in the scanning probe comprises an optical fiber that conducts laser light to the scanning probe from a laser outside the probe. 
     
     
         7 . The apparatus of  claim 1  wherein:
 the laser optical element comprises a conical laser-reflective optical element; and 
 the laser light source and the conical laser-reflecting optical element are configured so that the conical laser-reflecting optical element, when illuminated by the laser light source, projects a broken ring of laser light upon an interior surface of the ear when the ear probe is positioned in the ear. 
 
     
     
         8 . The apparatus of  claim 1  wherein:
 the laser optical element comprises a laser optic lens; and 
 the laser light source and the laser optic lens are configured so that the laser optic lens, when illuminated by the laser light source, projects upon the object laser light from a front surface of the laser optic lens. 
 
     
     
         9 . The apparatus of  claim 1  wherein the wide angle lens has a sufficient depth of field so that an entire portion of a surface of the scanned object illuminated by laser light is in focus at the image sensor. 
     
     
         10 . The apparatus of  claim 1  wherein constructing a 3D image of the scanned object further comprises, for a sequence from the image sensor of 2D images of the scanned object taken when the scanned object is illuminated by laser light from the scanning probe:
 detecting ridge points for each 2D image, the detecting further comprising identifying a set of brightest pixels for each 2D image, each set depicting a pattern of laser light reflected from a surface of the scanned object; 
 transforming, in dependence upon a predefined association between each pixel in the image sensor and corresponding points in scanner space, the ridge points to points in scanner space; and 
 transforming, in dependence upon a relationship between an origin of a coordinate system defining scanner space and an origin of another coordinate system defining object space, the points in scanner space to points in object space. 
 
     
     
         11 . The apparatus of  claim 1  wherein constructing the 3D image further comprises constructing the 3D image in dependence upon a sequence of images captured by the image sensor as the probe is moved relative to the scanned object. 
     
     
         12 . The apparatus of  claim 1  wherein the scanned object is an ear. 
     
     
         13 . The apparatus of  claim 1  wherein the scanned object is an interior portion of an ear. 
     
     
         14 . The apparatus of  claim 1  further comprising the scanning probe configured to extend into an orifice of a human body. 
     
     
         15 . The apparatus of  claim 1  wherein the laser light source comprises an optical fiber that extends further distally than the wide angle lens and into a field of view of the wide angle lens. 
     
     
         16 . A method of determining a geometry of a three dimensional scanned object, the method comprising:
 projecting, with a light source, a pattern of light to a location in a coordinate system, wherein at least a partial lateral portion of the pattern of light illuminates a surface of the scanned object; and   determining a position of the lateral portion in the coordinate system using an image sensor with a focal surface, the focal surface including the location.   
     
     
         17 . The method of  claim 16  further comprising:
 moving the light source to illuminate different surfaces of the scanned object; and 
 repeating the projecting and determining steps for each of the different surfaces. 
 
     
     
         18 . The method of  claim 16  further comprising:
 determining a position of a scanned object in the coordinate system; and 
 correlating positions of lateral portions of different surfaces of the scanned object with the position of the scanned object in the coordinate system; and 
 
     
     
         19 . The method of  claim 16  further comprising:
 determining a position of a scanned object in the coordinate system; 
 correlating positions of lateral portions of different surfaces of the scanned object with the position of the scanned object in the coordinate system; and 
 assembling a three-dimensional shape using the correlated positions of the lateral portions. 
 
     
     
         20 . The method of  claim 16  wherein the scanned object is an ear.