Apparatus and method for monitoring intraocular and blood pressure by non-contact contour measurement

• US 6,110,110 A
• Filed: 09/22/1998
• Issued: 08/29/2000
• Est. Priority Date: 08/04/1993
• Status: Expired due to Term

• Current Assignee: Lois G. Dublin, Randall E. Nieman, Richard E. Nieman, Wilbur Leslie Jr. Dublin
• Original Assignee: Lois G. Dublin, Randall E. Nieman, Richard E. Nieman, Wilbur Leslie Jr. Dublin
• Inventors: Dublin, Wilbur Leslie Jr., Dublin, Lois G., Nieman, Randall E., Nieman, Richard E.
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): SZMAL, BRIAN SCOTT
• Application Number:
  US09/158,669
• Time in Patent Office: 707 Days
• Field of Search: 600/405, 600/401, 600/398, 600/399, 600/400, 128/645, 128/652, 128/649
• US Class Current: 600/405
• CPC Class Codes: A61B 3/165 Non-contacting tonometers
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence

Abstract

The present invention describes apparatus and methods for long-term, repeatable measurement of pressure in vessels by measuring distortion signatures of the external surfaces of a vessel through calibration against a known and verifiable reference standard. It is particularly useful for measuring intraocular pressure, pressure in blood vessels and other physiological pressures. It is also adaptable for measuring pressure changes in virtually any vessel whose external surface is deformable such that pressure changes are transduced to the external surface of the confining vessel, as exemplified by process piping.

Claims

1. A system for measuring pressure in a vessel having a pressure deformable surface, the system comprising:

a light beam emitter means for emitting a coherent light beam impinging directly upon the vessel surface without surface distortion, resulting in a light beam reflected from the vessel surface;

a light beam detector spaced relative to the emitter for detecting the light beam reflected from the vessel surface; and

,

a signal processor means for determining changes in the pressure deformable surface of the vessel as a function of changes in the reflected light beam'"'"'s position on the detector.

2. The system of claim 1 wherein the vessel is a physiological vessel.

3. The system of claim 2 wherein the physiological vessel is an eye or a blood vessel.

4. The system of claim 1 wherein the vessel is an essentially nondeformable vessel fitted with a pressure sensitive patch.

5. The system of claim 1 further comprising three-dimensional signatures obtained from two-dimensional stereoscopic, or three-dimensional scanner.

6. The system of claim 1 further comprising a reference point on the vessel to normalize scans of slightly differing register to correct signatures for deviations in register between components of the system.

7. The system of claim 1 further comprising calibrating the changes in reflected light against changes determined from a known standard.

8. The system as recited in claim 1, wherein the light emitter comprises a light emitting diode.

9. The system as recited in claim 1, wherein the light emitter comprises a laser.

10. The system as recited in claim 1, wherein the light detector comprises a photodiode.

11. The system as recited in claim 1, wherein the light detector comprises a photodiode array.

12. The system as recited in claim 1, wherein the light detector comprises a charge coupled device.

13. The system as recited in claim 1, wherein the light emitter and detector are coupled to a scanner which moves the emitter and detector in close proximity across the outer vessel surface.

14. The system as recited in claim 13, wherein the scanner comprises:

a platform having the emitter and detector fixed in spaced relation to one another; and

a motor drive source attached to the platform for scanning the platform across the vessel surface.

15. The system as recited in claim 1, wherein the vessel is an eye and wherein the light beam detector comprises:

at least one photodetector configured to receive a light beam reflected from the eye and convert the light beam to an electrical signal; and

at least one amplifier coupled to the photodetector for amplifying the electrical signal.

16. The system as recited in claim 15, further comprising a local memory medium for storing the electrical signals and/or images.

17. The system as recited in claim 16, wherein the signal processor comprises:

a first remote memory medium for accumulating a set of stored values to allow conversion of alterations in the electrical signal to changes in intraocular pressure;

a second remote memory medium for accumulating a set of stored values to allow conversion of alterations in the electrical signal to changes in blood pressure; and

a computer adapted for connection to the first and second memory media for converting alterations in the electrical signal to intraocular pressure and blood pressure.

19. The system of claim 1 further comprising full-field three-dimensional image mapping means.

20. The system of claim 1 further comprising an eyeglasses frame attached to the system.

21. The system of claim 20 further comprising an opaque goggle.

18. A two-dimensional stereo angles and axis for simultaneous line of intersection a5 same distance.