Intraocular pressure recording system

• US 20040186366A1
• Filed: 01/29/2004
• Published: 09/23/2004
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: EPFL - Ecole Polytechnique Federale de Lausanne
• Original Assignee: EPFL - Ecole Polytechnique Federale de Lausanne
• Inventors: Metz, Stefan, Bertrand, Daniel, Leonardi, Matteo, Leuenberger, Peter
• Granted Patent: US 7,137,952 B2
• Time in Patent Office: Days
• US Class Current: 600/398
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00

Abstract

A new noninvasive approach for intraocular pressure (IOP) measurement allowing continuous monitoring over prolonged periods, regardless of patient'"'"'s position and activities. The key element of this measurement method is a soft contact lens (1) including at least one strain gage (2) longitudinally arranged around the center of the contact lens and capable of measuring precisely spherical deformations of the eyeball induced by the changes in IOP. This information is transmitted with wires or (preferably) wirelessly in real time to an external recording system (14). The system is placed in the same way as a normal corrective contact lens, no anesthesia is required and patient vision remains almost completely unimpaired.

Claims

1. Intraocular pressure recording system comprising a soft contact lens (1) such as a silicone contact lens and an active strain gage (2) fixed to said contact lens (1), characterized by the fact that said active strain gage (2) has a circular arc shape and is situated around the center (C) of said soft contact lens (1).

2. Intraocular pressure recording system according to claim 1 wherein said active strain gage (2) is made of a resistive material, such as a metal or an alloy.

3. Intraocular pressure recording system according to claim 2 wherein said active strain gage (2) is a continuous longitudinal element.

4. Intraocular pressure recording system according to claim 3 wherein said continuous longitudinal element is placed in such a way that several of its portions (3) are disposed parallel to each other.

5. Intraocular pressure recording system according to any of the previous claims 1 to 4 wherein said active strain gage (2) has a circular shape.

6. Intraocular pressure recording system according to any of the previous claims 1 to 5 further comprising a passive strain gage (5).

7. Intraocular pressure recording system according to claim 6 wherein said passive strain gage (5) has a general circular arc shape made of a continuous meridional element placed in such a way that several of its portions (7) are radially arranged.

8. Intraocular pressure recording system according to any of the previous claims 1 to 7 wherein said active strain gage (2) is shaped in order to be placed on the corneosclera junction.

9. Intraocular pressure recording system according to any of the previous claims 1 to 8 including a wireless telemetry system (12-15) for data transmission with said strain gage(s) (2,5).

10. Intraocular pressure recording system according to any of the previous claims 1 to 9 wherein at least one of said continuous longitudinal or meridional element is microfabricated.

11. Intraocular pressure recording system according to any of the previous claims 1 to 9 wherein at least one of said continuous longitudinal or meridional element is a wire.

12. Intraocular pressure recording system according to any of the previous claims 1 to 11 wherein said contact lens (1) furthermore comprises other measuring devices such as an ElectroRetinoGraph or a chemical analysis sensor.

13. Intraocular pressure recording system according to any of the previous claims 1 to 12 wherein it comprises several active gages (2).

14. Intraocular pressure recording system according to any of the previous claims 1 to 13 wherein it comprises several passive gages (5).

15. Intraocular pressure recording system according to any of the previous claims 1 to 14 wherein it comprise four gages in a Wheatstone bridge configuration, such as two active gages and two passives ones being placed alternatively on the bridge.