Otoscanner With Fan And Ring Laser

Abstract

An otoscanner including a conical laser-reflective optical element and a 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 and a diffractive laser optic lens and the laser light source and the diffractive laser optic lens are configured so that the diffractive laser optic lens, when illuminated by the laser light source, projects upon an interior surface of the ear a fan of laser light at a predetermined angle with respect to a front surface of the diffractive laser optic lens when the ear probe is positioned in the ear.

What is claimed is: 
     
         1 . An otoscanner comprising:
 an otoscanner body, the body comprising a hand grip, the body having mounted upon it an ear probe, a tracking illumination emitter, a plurality of tracking illumination sensors, and a display screen, the otoscanner body having mounted within it an image sensor;   the ear probe comprising a wide-angle lens optically coupled to the image sensor, laser light source, a first laser optical element, a second laser optical element and a source of non-laser video illumination;   the plurality of tracking illumination sensors disposed upon the otoscanner body so as to sense reflections of tracking illumination emitted from the tracking illumination emitter and reflected from tracking targets installed at positions that are fixed relative to the scanned ear;   the display screen coupled for data communications to the image sensor, the display screen displaying images of the scanned ear, and   the image sensor coupled for data communications to a data processor, with the data processor configured so that it functions by constructing, in dependence upon a sequence of images captured when the scanned ear is illuminated by laser light and tracked positions of the ear probe inferred from reflections of tracking illumination sensed by the tracking illumination sensors, a 3D image of the interior of the scanned ear.   wherein the first 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.   wherein the second laser optical element comprises a diffractive laser optic lens and the laser light source and the diffractive laser optic lens are configured so that the diffractive laser optic lens, when illuminated by the laser light source, projects upon an interior surface of the ear a fan of laser light at a predetermined angle with respect to a front surface of the diffractive laser optic lens when the ear probe is positioned in the ear.   
     
     
         2 . The otoscanner of  claim 1  wherein the laser light source in the ear probe comprises an optical fiber that conducts laser light to the ear probe from a laser outside the probe. 
     
     
         3 . The otoscanner of  claim 1  wherein the laser light source comprises a laser mounted in the probe. 
     
     
         4 . The otoscanner of  claim 1  wherein:
 the wide angle lens has a sufficient depth of field so that the entire portion of the interior surface of the ear illuminated by laser light is in focus at the image sensor. 
 
     
     
         5 . The otoscanner of  claim 1  wherein:
 the image sensor operates at a video frame rate that is twice a standard video frame rate; 
 the laser light source is strobed during capture by the image sensor of alternate video frames; 
 video frames are captured by the image sensor when only the non-laser video illumination illuminates the scanned ear; and 
 images for constructing 3D images are captured by the image sensor only when the strobed laser light illuminates the scanned ear. 
 
     
     
         6 . The otoscanner of  claim 1  wherein:
 the tracking targets comprise retroreflectors; and 
 the tracking illumination is provided from a tracking illumination source mounted on the otoscanner body. 
 
     
     
         7 . The otoscanner of  claim 1  wherein the tracking illumination is infrared. 
     
     
         8 . The otoscanner of  claim 1  wherein constructing a 3D image of the interior of a scanned ear further comprises, for a sequence from the image sensor of 2D images of the ear taken when the ear is illuminated by a ring of laser light from the ear 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 c-shaped broken ring of laser light reflecting from a surface of the scanned ear; 
 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 ear space, the points in scanner space to points in ear space. 
 
     
     
         9 . The otoscanner of  claim 1  wherein the display screen displaying images of the scanned ear further comprises the display screen displaying video images from the image sensor of the scanned ear illuminated only by non-laser video illumination. 
     
     
         10 . The otoscanner of  claim 1  wherein:
 the otoscanner further comprises the display screen coupled for data communications to the data processor; and 
 the display screen displaying images of the scanned ear further comprises the display screen displaying the 3D image of the interior of the scanned ear. 
 
     
     
         11 . The otoscanner of  claim 1  wherein:
 the otoscanner body has mounted within it pressure sensors operably coupled to the ear probe and coupled for data communications to the data processor, the pressure sensors detecting the force with which the ear probe is pressed against a surface of the scanned ear. 
 
     
     
         12 . The otoscanner of  claim 1  wherein the data processor is further configured to function by:
 determining the position of the probe in ear space when the probe is positioned at the aperture of the auditory canal of the scanned ear; and 
 setting the position of the probe at the aperture of the auditory canal of the scanned ear as the origin of the coordinate system defining ear space. 
 
     
     
         13 . The otoscanner 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 in the scanned ear. 
     
     
         14 . The otoscanner 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 in the scanned ear with mouth open. 
     
     
         15 . The otoscanner 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 in the scanned ear with mouth closed. 
     
     
         16 . The otoscanner of  claim 1  wherein the data processor is further configured to function by determining whether a scan is complete, the determining carried out in dependence upon a class, make, and model, of a hearing aid. 
     
     
         17 . The otoscanner of  claim 1  wherein the processor is further configured to function by:
 inferring, from a tracked position of the ear probe, previously recorded statistics describing typical ear sizes according to human demographics, and currently recorded demographic information regarding a person whose ear is scanned, the actual present position of the ear probe in relation to at least one part of the scanned ear; and 
 providing a warning when the probe moves within a predefined distance from the part of the scanned ear. 
 
     
     
         18 . The otoscanner of  claim 1  wherein constructing a 3D image of the interior of the scanned ear further comprises determining the location and orientation in ear space of the ear drum of the scanned ear.