Devices and Methods for Noninvasive Measurement of Intracranial Pressure

• US 20130211285A1
• Filed: 03/14/2013
• Published: 08/15/2013
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: Third Eye Diagnostics, Inc.
• Original Assignee: Third Eye Diagnostics, Inc.
• Inventors: Lai, William, Fuller, Terry A.
• Granted Patent: US 9,585,578 B2
• Time in Patent Office: Days
• US Class Current: 600/561
• CPC Class Codes: A61B 3/0066 with identification means for the apparatus
• CPC Class Codes: A61B 3/16 for measuring intraocular pressure, e.g. tonometers
• CPC Class Codes: A61B 5/031 Intracranial pressure
• CPC Class Codes: A61B 5/6821 Eye
• CPC Class Codes: A61B 8/10 Eye inspection
• CPC Class Codes: A61B 8/4218 characterised by articulated arms
• CPC Class Codes: A61B 8/488 involving Doppler signals
• CPC Class Codes: A61B 8/5223 for extracting a diagnostic or physiological parameter from medical diagnostic data for algorithms to analyse biomedical images G06T7/0012

Abstract

Provided are systems and methods for noninvasively assessing intracranial pressure by controllably osculating at least a portion of a subject'"'"'s ocular globe while applying a force sufficient to collapse an intraocular blood vessel and correlating the collapse pressure to intracranial pressure. Also provided are ophthalmic components useful in ophthalmic imaging applications, such as retinal, corneal, and pupil imaging. The components may include an optical contact surface that has a radius of curvature that is greater than the radius of curvature of a subject'"'"'s cornea.

Claims

17. A method of estimating a pressure in a subject, comprising:

imaging an intraocular blood vessel while applying a force to the subject'"'"'s ocular globe,

the force being applied through a component having a contact surface that osculates a portion of the subject'"'"'s ocular globe,

the force being sufficient to collapse an intraocular blood vessel.

18. The method of claim 17, further comprising correlating the force that collapses the intraocular blood vessel to an estimated intracranial pressure of the subject.

19. The method of claim 17, wherein the force is applied to the cornea of the subject, to the sclera of the subject, to the eyelid of the subject, or any combination thereof.

20. The method of claim 17, wherein at least some of the force is applied by advancing the component.

21. The method of claim 17, wherein at least some of the force is applied by increasing a pressure within the component so as to exert a force against the subject.

22. The method of claim 17, further comprising measuring the deflection of a reflective portion of the component that deflects during force application.

23. The method of claim 22, further comprising measuring radiation reflected from the reflective portion of the component.

24. The method of claim 22, further comprising measuring a change in radiation related to deflection of the reflective portion of the component.

25. The method of claim 17, wherein the contact surface is characterized as being concave.

26. The method of claim 25, wherein the contact surface has a radius of curvature greater than about 7 mm.

27. The method of claim 17, wherein the osculated area of the ocular globe remains essentially constant during force application.

28. The method of claim 17, further comprising using a strain gauge of the component to estimate the force.

29. The method of claim 17, further comprising illuminating the pupil of the subject with illumination sufficient to stimulate the pupil

30. The method of claim 29, further comprising measuring at least of one pupil latency, pupil constriction velocity, pupil dilation velocity, or any combination thereof.

31. A system for measuring intracranial pressure in a subject, comprising:

an ophthalmic component having a having an osculating optical surface adapted to contact a subject'"'"'s ocular globe; and

a force applicator.

1. An ophthalmic component, comprising:

a body having an osculating surface adapted to osculate a subject'"'"'s ocular globe, and

the body being adapted to engage with an instrument.

2. The ophthalmic component of claim 1, wherein the osculating surface is characterized as being a concave optical surface having a radius of curvature.

3. The ophthalmic component of claim 2, wherein the radius of curvature of the concave optical surface is greater than the radius of curvature of a subject'"'"'s cornea.

4. The ophthalmic component of claim 2, wherein the radius of curvature of the concave optical surface is greater than about 7 mm.

5. The ophthalmic component of claim 1, wherein the osculating surface comprises a deformable material.

6. The ophthalmic component of claim 1, wherein the component defines an enclosed control volume in mechanical communication with the osculating surface.

7. The ophthalmic component of claim 6, wherein the control volume is configured to be pressurized while in contact with a subject'"'"'s ocular globe.

8. The ophthalmic component of claim 6, further comprising a passage placing the control volume into fluid communication with the environment exterior to the control volume.

9. The ophthalmic component of claim 1, wherein the osculating surface comprises a material having a thickness in the range of from about 0.005 inches to about 0.060 inches.

10. The ophthalmic component of claim 1, wherein the osculating surface comprises a material having an ultimate elongation of from about 200% to about 1000%, a 300% modulus of from about 1.5 MPa to about 4.0 MPa, a ultimate tensile strength of from about 20 MPa to about 40 MPa, or any combination thereof.

11. The ophthalmic component of claim 1, further comprising a projection adapted to engage with an instrument.

12. The ophthalmic component of claim 1, further comprising a deflectable projection.

13. The ophthalmic component of claim 12, wherein the deflectable projection comprises a material that is reflective to electromagnetic radiation.

14. The ophthalmic component of claim 1, further comprising a lens in optical communication with the osculating surface.

15. The ophthalmic component of claim 1, further comprising a strain gauge.

16. The ophthalmic component of claim 15, wherein the strain gauge comprises a strain gauge pattern disposed on the component, the strain gauge pattern being configured to measure deflection of a portion of the component during contact with a subject.

32. The system of claim 31, wherein the osculating optical surface of the ophthalmic component is characterized as being concave and has a radius of curvature of at least about 7 mm.

33. The system of claim 31, wherein the ophthalmic component is configured to engage an engagement region of the system.

34. The system of claim 31, wherein the force applicator is configured to advance the ophthalmic component against a subject'"'"'s ocular globe.

35. The system of claim 31, wherein the force applicator is configured to increase a pressure within the ophthalmic component.

36. The system of claim 31, further comprising an imager.

37. The system of claim 31, wherein the imager is configured to collect an image of the cornea, an intraocular blood vessel, the pupil, or any combination thereof.

38. The system of claim 35, the system being configured to correlate a change in radiation reflected from the reflective portion of the component to a force applied through the component.

39. The system of claim 35, further comprising a source of illumination.

40. The system of claim 39, wherein the source of illumination is configured to stimulate the pupil of the subject.

41. The system of claim 40, wherein the system is configured to measure at least of one pupil latency, pupil constriction velocity, pupil dilation velocity, or any combination thereof

35-1. The system of claim 31, wherein the component comprises a reflective portion adapted to deflect when the osculating optical surface of the component is exerted against a subject'"'"'s ocular globe.

36-2. The system of claim 35, further comprising a device configured to illuminate the reflective portion.

37-3. The system of claim 35, wherein the system is configured to measure radiation reflected from the reflective portion of the component, to measure a change in radiation reflected from the reflective portion of the component, or both.