TONOMETER

• US 20110060208A1
• Filed: 10/24/2004
• Published: 03/10/2011
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Joshua Gur
• Original Assignee: Joshua Gur
• Inventors: Gur, Joshua
• Granted Patent: US 8,216,140 B2
• Time in Patent Office: Days
• US Class Current: 600/398
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers

Abstract

A non-contact tonometer for measuring the intra-ocular pressure of an eye, projecting light into the eye and measuring the reflected light as affected by mechanical distortion. The cornea is distorted by delivering a pneumatic pulse. The tonometer consists mainly of an electro-optical unit mountable on the head of a user and a control unit. The control unit of the tonometer includes a display and optionally an audio device for instructing the user. The electro-optical unit employs a tubular wave guide, a light detector, and a reflector for deflecting a light beam to the eye and for eliminating a part of the reflected light reaching the detector. The aligning of the tonometer with the head of the user is optionally assisted by a reticle observed.

Claims

1. A method for measuring internal pressure of a body comprising:

aligning a longitudinal axis of a light projecting and collecting device with said body;

detecting changes of intensity of light reflected from a convex sector of a surface of said body and delivered by total internal reflection in a light guide, and wherein said changes are related to a distortion induced by a pneumatic pulse, and

matching a time-related feature associated with said changes of said light intensity measured with a given pressure value, wherein said time related-feature is any of the following;

a time length of said pneumatic pulse, a time interval in which said changes of said light intensity measured are detected, a slope of said changes of said light intensity measured.

2. A method for measuring internal pressure of a body as in claim 1, wherein said time-related feature is a slope of said changes of said light intensity measured.

3. A method for measuring internal pressure of a body as in claim 1, wherein said body is an eye.

4. A method for measuring internal pressure of a body as in claim 1 and wherein said light projecting and collecting device is a unitary light projecting and collecting device tube (LPCT).

5. A method for measuring internal pressure of a body as in claim 1, wherein said aligning is carried out using a user observed reticle.

7. A device for measuring internal pressure of a deformable body as in claim 5 and wherein said deformable body is an eye.

6. A device for measuring internal pressure of a deformable body wherein changes in the reflectance of a sector of said body are measured in correlation with a distortion of said body effected by a pneumatic pulse, and wherein said sector located within a convex surface of said body, said device comprising:

a first tube having a substantially thick wall pointing at said sector wherein the proximal face of said wall is adapted to receive light reflected from said body;

a second tube for conveying pneumatic pulse to said deformable body;

a light detector receiving light from said wall of said first tube, and

a reflector used for both deflecting a beam of light of a light source through the lumen of said first tube to said body and for blocking reflected light from said body.

8. A device for measuring internal pressure of a deformable body as in claim 6 comprising in addition a reticle for projecting an image thereof on said eye.

9. A device for measuring internal pressure of a deformable body as in claim 6 and wherein said light detector is connected to a control unit which also compares the curve of changing reflection of light as correlated with a transient deformation of the eye with stored equivalent slopes of eyes having given internal pressure values.

10. A device for measuring internal pressure of a deformable body as in claim 6 and wherein a mounting is included for securing said the device to the head of the user.