Eye model
An eye model comprises a sclera simulation which is made of a bright plastic material and a pattern which contrasts in color with the sclera simulation, the pattern simulating an eye pupil and/or an iris structure. The eye model is used to calibrate an eye tracking system.
1. A test device for testing functionality of and calibrating an eye tracker configured for use with a laser device for refractive eye surgery, using an eye model, comprising:
an eye model comprising:
a flattened area forming a cover surface of the eye model;
a sclera simulation which is made of a bright plastic material, the plastic material containing a polyvinyl chloride at least as the main component, the sclera simulation forming an annular surface in accordance with the shape of a spherical or ellipsoidal surface, the sclera simulation surrounding the flattened area;
a pattern which contrasts in color with the sclera simulation, the pattern simulating an eye pupil and an iris structure wherein the pattern is situated on the flattened area;
wherein the material of the sclera simulation is configured to appear white and the pattern is configured to contrast in color with the sclera simulation under infrared illumination; and
a flattened base area on the side of the annular surface opposite from the pattern, the region of the flattened base area provided with a threaded hole;
a positioning device configured to mechanically adjust the position and orientation of the eye model, the threaded hole used to arrange the eye model to the positioning device, wherein the eye model is movable by the positioning device to different positions and orientations;
an eye tracker configured to detect and quantify the movement of the eye model as it is moved by the positioning device;
wherein the eye tracker further comprises:
an infrared camera configured to record infra-red images of the eye model as it is moved by the positioning device, wherein the images contain the pattern and at least one portion of the sclera simulation which adjoins the pattern; and
a processing unit which is configured for determining a position and/or an orientation of the pattern within recorded infrared images.
2. The device of claim 1 , wherein the plastic material is white in the area of the sclera simulation.
3. The device of claim 1 , wherein the transition from the annular surface to the flattened area is formed by a ring-shaped edge.
4. The device of one of claim 1 , wherein the pattern is formed by imprinting or painting of the eye body, or by adhering to the eye body an adhesive element which bears the pattern.
5. The device according to one of claim 1 , wherein the surface of the eye body in the area of the sclera simulation forms a convexly curved annular surface.
6. The device according to claim 1 wherein the eye model is situated on a patient table in the area of a head support of the patient table while the images are recorded.
7. The device of claim 1 wherein the processing unit is further configured to determine a position of a center of the eye pupil and/or an orientation of the simulation of the iris structure within the recorded infrared images to calibrate the eye tracker.
8. The device of claim 1 wherein the positioning device is further configured to adjust the position and orientation of the eye model to simulate translational eye movement along an axis perpendicular to an optical axis and rotational eye movement about the optical axis.