Automated fundus imaging system

Abstract

An apparatus for obtaining a retinal image of an eye has a control logic processor for executing a sequence of operations for obtaining the image. A visual target orients the eye of a patient when viewed. An indicator element provides a signal that indicates that the patient is in position. A cornea focus detection section indicates cornea focus, in cooperation with the control logic processor. An alignment actuator aligns the optical path according to a signal obtained from the cornea focus detection section. A retina focus detection section detects retina focus in cooperation with the control logic processor. A focusing actuator is controlled by instructions from the control logic processor according to a signal obtained from the retina focus detection section. An image capture light source is energized by the control logic processor for illuminating the retina.

1 . An apparatus for obtaining a retinal image from an eye, comprising: 
 a) a control logic processor for executing a sequence of operations for obtaining the image;    b) a visual target for orienting the eye of a patient when the target is viewed by the patient;    c) an indicator element for providing a signal that indicates that the patient is in position for imaging;    d) a cornea focus detection section for providing an indication of cornea focus, in cooperation with the control logic processor;    e) an alignment actuator for aligning an optical path of the apparatus according to a signal obtained from the cornea focus detection section;    f) a retina focus detection section for detecting retina focus in cooperation with the control logic processor;    g) a focusing actuator controlled by instructions from the control logic processor according to a signal obtained from the retina focus detection section; and    h) an image capture light source energized by the control logic processor for illuminating the retina for image capture,    wherein the cornea focus detection section comprises:    an aperture element alternately illuminated from first and second light sources, wherein the first and second light sources are switched alternately on and off;    a lens assembly for imaging the aperture element onto the cornea;    a cornea sensor for sensing the aperture element image on the cornea and providing sensed cornea image data to the control logic processor; and    an actuator for adjusting the focus position of components in an imaging path, the actuator controlled according to instructions from the control logic processor, based on the sensed cornea image data.    
   
   
       2 . An apparatus according to  claim 1  wherein the first and second light sources are LEDs.  
   
   
       3 . An apparatus according to  claim 1  wherein the cornea sensor comprises a charge-coupled device sensor.  
   
   
       4 . An apparatus according to  claim 1  wherein the cornea sensor comprises a CMOS sensor.  
   
   
       5 . An apparatus according to  claim 1  wherein the retina focus detection section comprises: 
 a) an aperture alternately illuminated from first and second light sources;    b) a lens assembly for imaging the aperture onto the retina;    c) a retina sensor for sensing an image of the retina and providing sensed retina image data to the control logic processor; and    d) a focus actuator for adjusting the focus position of components in an imaging path, the focus actuator controlled according to instructions from the control logic processor, based on the sensed retina image data.    
   
   
       6 . An apparatus according to  claim 5  wherein the first and second light sources are LEDs.  
   
   
       7 . The retina focusing section of  claim 5  wherein the first and second light sources are formed by a prism pair.  
   
   
       8 . The retina focusing section of  claim 5  wherein at least one of the first and second light sources is directed through an optical fiber.  
   
   
       9 . A cornea focusing section in an apparatus for obtaining an image of the eye, comprising: 
 a) a control logic processor for executing an automated sequence of operations for obtaining the image;    b) a cornea focus detection section comprising: 
 i) an aperture illuminated from first and second light sources, wherein the first and second light sources are switched alternately on and off;  
 ii) a lens assembly for imaging the aperture onto the cornea;  
 iii) a cornea sensor for sensing an image of the cornea and providing sensed cornea image data to the control logic processor; and  
   c) an actuator for adjusting the focus position of components in an imaging path, the actuator controlled according to instructions from the control logic processor, based on the sensed cornea image data.    
   
   
       10 . The cornea focusing section of  claim 9  wherein the first and second light sources are LEDs.  
   
   
       11 . The cornea focusing section of  claim 9  wherein the cornea sensor comprises a charge-coupled device.  
   
   
       12 . The cornea focusing section of  claim 9  wherein the cornea sensor comprises a CMOS device.  
   
   
       13 . The cornea focusing section of  claim 9  wherein the cornea sensor comprises two or more sensing devices.  
   
   
       14 . The cornea focusing section of  claim 9  wherein the cornea focus detection section further comprises a folding element.  
   
   
       15 . A retina focusing section in an apparatus for obtaining an image of the eye, comprising: 
 a) a control logic processor for executing an automated sequence of operations for obtaining the image;    b) a retina focus detection section comprising: 
 i) an aperture illuminated from first and second light sources wherein the first and second light sources are switched alternately on and off;  
 ii) a lens assembly for imaging the aperture onto the retina;  
 iii) a retina sensor for sensing an image of the retina and providing sensed retina image data to the control logic processor; and  
   c) a focus actuator for adjusting the focus position of components in an imaging path, the focus actuator controlled according to instructions from the control logic processor, based on the sensed retina image data.    
   
   
       16 . The retina focusing section of  claim 15  wherein the first and second light sources are LEDs.  
   
   
       17 . The retina focusing section of  claim 15  wherein the retina sensor comprises a charge-coupled device.  
   
   
       18 . The retina focusing section of  claim 15  wherein the retina sensor comprises a CMOS device.  
   
   
       19 . The retina focusing section of  claim 15  wherein the retina focus detection section further comprises a folding element.  
   
   
       20 . A method for obtaining a retinal image comprising: 
 a) displaying a visual target for orienting the eye of the patient;    b) accepting a signal from an indicator element that is actuated by the patient to confirm visibility of the visual target;    c) detecting cornea focus by alternately illuminating a cornea detection aperture from a first and a second light source, imaging the cornea detection aperture onto the cornea, and sensing the imaged cornea detection aperture;    d) aligning optical components according to the detected cornea focus;    e) detecting retina focus by alternately illuminating a retina detection aperture from a third and a fourth light source, imaging the retina detection aperture onto the cornea, and sensing the imaged retina detection aperture;    f) adjusting a focusing actuator according to the retina focus;    g) illuminating the retina for image capture; and    h) energizing an image capture light source and obtaining an image.    
   
   
       21 . The method of  claim 20  wherein the step of accepting a signal from an indicator element comprises the step of obtaining the input signal from a sensor that automatically detects the proximity of the patient.  
   
   
       22 . The method of  claim 20  wherein the step of accepting a signal from an indicator element comprises the step of obtaining the input signal from a switch that is operated by the patient.  
   
   
       23 . The method of  claim 20  wherein the step of accepting a signal from an indicator element comprises the step of obtaining the input signal from a touchscreen entry by the patient.  
   
   
       24 . A method for focusing on the cornea of an eye comprising: 
 a) illuminating an aperture from first and second light sources, wherein the first and second light sources are switched alternately on and off;    b) imaging the aperture onto the cornea;    c) sensing an image of the cornea and providing sensed cornea image data to a control logic processor;    d) controlling an actuator to adjust the focus position of components in an imaging path; and    wherein the actuator is controlled automatically, according to instructions from the control logic processor, based on the sensed cornea image data.    
   
   
       25 . The method of  claim 24  wherein the step of sensing an image of the cornea comprises directing reflected light from the cornea to a CCD sensor.  
   
   
       26 . The method of  claim 24  wherein the step of sensing an image of the cornea comprises directing reflected light from the cornea to a CMOS sensor.  
   
   
       27 . A method for focusing on the retina of an eye comprising: 
 a) illuminating an aperture from first and second light sources;    b) imaging the aperture onto the retina;    c) sensing an image of the retina and providing sensed retina image data to a control logic processor;    d) controlling an actuator to adjust the focus position of components in an imaging path; and    wherein the actuator is controlled automatically, according to instructions from the control logic processor, based on the sensed retina image data.    
   
   
       28 . The method of  claim 27  wherein the step of illuminating an aperture comprises the step of alternately illuminating the first and second light sources.