Method and system to identify intraocular pressure (IOP) of an eye

9,277,862

14/114917

August 14, 2012

Non-tactile and non-evasive tonometer utilizing air flow with a definite amount of pressure to the eye and a mechanism to deflate the thin foil set that is placed near to eye ball such that re-bounded air hits on it. The mechanism involves acquiring or capturing then the images of the known pattern marking on thin foils both before and after deflating process due to rebounded air. On evaluating the deformation of the pattern appearing in the images obtained before and after air flow and calibrating the deformation with respect to size, translation, rotation and scaling parameters due the different pressure level that hits the eye ball and that rebounds on to thin foils, we arrive at a scheme of measuring the intraocular pressure of human eye. This intraocular pressure is used as a parameter for the ophthalmologist to diagnose glaucoma impairment of human beings.

Rao, Shyam Vasudeva (Karnataka, IN); Chandrasekhar, Kuppuswamy (Karnataka, IN); Bhatt, Mahabaleswara Ram (Karnataka, IN)

FORUS HEALTH PVT. LTD. (Bangalore, Karntaka, IN)

1. A method to identify Intraocular Pressure (IOP) of an eye, said method comprising acts of: placing a foil-flap support assembly between an imaging unit and the eye, wherein the foil-flap support assembly has a transparent stiff foil fixed to a support and plurality of movable flaps suspended from the support facing the eye; blowing air of predetermined amount of pressure onto an eye ball of the eye through an air channel, wherein the air blown to the eye ball rebounds from the eye ball deflecting the flaps of the support assembly; capturing an image of the deflected foil-flap support assembly; identifying plurality of parameters value of the captured image; and comparing the plurality of parameters value with plurality of predetermined parameters value to identify IOP of the eye.

2. The method as claimed in claim 1 , wherein the predetermined amount of air pressure is in the range of 10 millimeter of Mercury (10 mmHg) to 100 millimeter of Mercury (100 mmHg).

3. The method as claimed in claim 1 , wherein the plurality of parameters value of the captured image is selected from at least one of size, length, breadth, width, shape, lateral shifts, rotation, translation, scaling or any combinations thereof.

4. The method as claimed in claim 1 , wherein the predetermined parameters value is determined from a normal eye by performing a calibration comprising steps of: a) placing the foil-flap support assembly between the eye and the imaging unit; b) capturing the image of the foil-flap support assembly; c) identifying the plurality of parameters value of the image; d) blowing the predetermined amount of air pressure through the air channel of a blowing unit onto an eye ball of the normal eye, wherein the air blown to the eye ball rebounds from the eye ball deflecting the foil-flap support assembly; e) capturing the image of the deflected foil-flap support assembly; f) identifying the plurality of parameters value of the image obtained from the step e); repeating the steps d), e) and f) for plurality of varying predetermined amount of air pressure; and storing the parameters value obtained for each varied air pressure.

5. A system to identify Intraocular Pressure (IOP) of an eye comprising: a foil-flap support assembly comprising: a transparent stiff foil fixed to a support; and plurality of movable flaps flexibly facing an eye suspended from the support; a control unit comprising: a blowing unit having an air channel to blow air of predetermined amount of pressure on to an eye ball of the eye; an imaging unit to capture image of the foil-flap support assembly before and after deflection; a computing device to identify plurality of parameters value of the captured image and to compare the identified parameters value with a predetermined parameters value determined during a calibration to identify IOP of the eye; and a storage unit to store calibrated parameters value.

6. The system as claimed in claim 5 , wherein the air channel is placed at a distance of 30 millimeter to 40 millimeter from the eye.

7. The system as claimed in claim 6 , wherein the air channel is selected from at least one of a transparent tube and non-transparent tube.

8. The system as claimed in claim 7 , wherein the transparent tube is selected from at least one of a glass tube, plastic tube and rubber tube.

9. The system as claimed in claim 7 , wherein the non-transparent tube is selected from at least one of a glass tube, plastic tube and metallic tube.

10. The system as claimed in claim 5 , wherein the transparent stiff foil and the plurality of movable flaps has a thickness in the range of 0.1 millimeter to 5.0 millimeter.

11. The system as claimed in claim 5 , wherein the transparent stiff foil and the plurality of movable flaps have a predefined color or prerequisite pattern different from one another.

12. The system as claimed in claim 5 , wherein the air channel comprises one or more openings of shape selected from circle and oval.

13. The system as claimed in claim 5 , wherein the one or more openings comprises at least one sensor to measure the reflected air pressure.

14. The system as claimed in claim 10 , wherein the transparent stiff foil and the plurality of movable flaps have a predefined color or prerequisite pattern different from one another.

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Kyoung Hwan Kim et al: “Intraocular pressure measurement devices using the micro reflected air pressure sensor for the pre-diagnosis of the glaucoma,” Nanotechnology (IEEE-NANO), 2010 10th IEEE Conference on, IEEE, Piscataway, NJ, USA, Aug. 17, 2010, pp. 907-910, XP031857562, ISBN: 978-1-4244-7033-4. cited by applicant
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