Devices and Methods for Noninvasive Measurement of Intracranial Pressure

• US 20130144185A1
• Filed: 12/02/2011
• Published: 06/06/2013
• Est. Priority Date: 12/02/2011
• Status: Active Grant

• Current Assignee: Third Eye Diagnostics, Inc.
• Original Assignee: Third Eye Diagnostics, Inc.
• Inventors: Wang, Yongping, Bellezza, Anthony, Lai, William, Fuller, Terry A.A.
• Granted Patent: US 9,078,612 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 3/14 Arrangements specially adapted for eye photography apparatus or arrangements for taking photographs per se G03B
• 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 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence

Abstract

Provided are systems and methods for noninvasively assessing intracranial pressure by controllably applanating at least a portion of a subject'"'"'s ocular globe so as to collapse an intraocular blood vessel and correlating the collapse pressure to intracranial pressure. Also provided are ophthalmic components useful in ophthalmic imaging applications, as well as methods of assessing intracranial pressure that are based, at least in part, on the degree of papilledema, if any, present in the subject.

Claims

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

imaging an intraocular blood vessel while applying a force that at least partially applanates a portion of the subject'"'"'s ocular globe and increases intraocular pressure to a level sufficient to collapse an intraocular blood vessel;

estimating, by imaging the at least partially applanated portion of the subject'"'"'s ocular globe, the intraocular pressure that collapses the intraocular blood vessel; and

correlating the estimated intraocular pressure that collapses the intraocular blood vessel to an estimated intracranial pressure of the subject.

2. The method of claim 1, 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

3. The method of claim 1, further comprising estimating the intraocular pressure that collapses the intraocular blood vessel by correlating one or more images of the at least partially applanated portion of the subject'"'"'s ocular globe to the applied force corresponding to the one or more images of the at least partially applanated portion of the subject'"'"'s ocular globe.

4. The method of claim 1, wherein estimating the pressure that collapses the intraocular blood vessel is accomplished while the at least a portion of the ocular globe is at least partially applanated.

5. The method of claim 1, wherein imaging comprises collecting an image on an image collector.

6. The method of claim 5, wherein the imaging of an intraocular blood vessel and the imaging of the at least partially applanated portion of the subject'"'"'s ocular globe is performed on a single image collector.

7. The method of claim 5, wherein the imaging of an intraocular blood vessel and the imaging of the at least partially applanated portion of the subject'"'"'s ocular globe are performed by different image collectors.

8. The method of claim 1, wherein the intracranial pressure estimate is based at least in part on Doppler ultrasound data collected from a periocular blood vessel of the subject.

9. The method of claim 1, wherein the intracranial pressure estimate is based at least in part on an assessment of the degree, if any, of papilledema present in the subject.

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

an applanator configured to controllably at least partially applanate a portion of a subject'"'"'s ocular globe,

a first image collector configured to collect light reflected from an intraocular blood vessel of the subject; and

an illumination train configured to direct light through an ophthalmic component to the intraocular blood vessel of the subject and to direct light reflected from the intraocular blood vessel to the first image collector.

11. The system of claim 10, wherein the ophthalmic component engages with the applanator.

12. The system of claim 10, wherein the ophthalmic component is configured to direct an image of an interface between the ophthalmic component and an applanated region of the ocular globe to the first image collector.

13. The system of claim 10, wherein the ophthalmic component bears one or more indicia and the system is capable of self-configuring at least one of the applanator, the image collector, or the illumination train in response to one or more indicia present on the ophthalmic component.

14. The system of claim 10, wherein the system is configured to, during operation, concurrently applanate at least a portion of the subject'"'"'s ocular globe and collect, on the first image collector, light reflected from the intraocular blood vessel of the subject.

15. The system of claim 14, wherein the system is further configured to collect, on the first image collector, light reflected from an interface between the ophthalmic component and the ocular globe of the subject.

16. The system of claim 14, wherein the system is further configured to collect, on a second image collector, light reflected from an interface between the ophthalmic component and the ocular globe of the subject.

17. The system of claim 10, further comprising a Doppler instrument configured so as to collect ultrasound data from a periocular blood vessel of the subject.

18. The system of claim 10, wherein the system is configured to estimate an intraocular pressure based on one or more of a force that least partially applanates the portion of a subject'"'"'s ocular globe, an area of the at least partially applanated portion of the subject'"'"'s ocular globe, or both.

19. The system of claim 10, the system being configured so as to be capable of assessing the degree, if any, of papilledema present in the subject.

20. The system of claim 10, further comprising a processor configured to estimate intracranial pressure of the subject based on one or more images of the at least partially applanated portion of the subject'"'"'s ocular globe and one or more images of the intraocular blood vessel of the subject.

21. The system of claim 20, the system being configured to compare the estimated intracranial pressure with an estimated intraocular pressure of the subject.

22. The system of claim 10, wherein the system is configured to, during operation, record retinal fundus images, score features of the optic disc using image processing algorithms, or both.

23. The system of claim 22, wherein the system is configured to compare feature scores to a database of images for so as to grade the purpose of grading papilledma, if present, according the Frisé

n Scale.

24. An ophthalmic component, comprising:

a body having an optical surface adapted to contact a subject'"'"'s cornea,

the body being adapted to engage with an applanating instrument, and

the component comprising a lens, a prism, or both.

25. The ophthalmic component of claim 24, wherein the body further comprises one or more indicia disposed thereon that identifies a structural, a functional or both characteristics of the component.

26. The ophthalmic component of claim 24, wherein the component comprises a plano lens, a convex lens, a prism lens, a concave lens, or any combination thereof.

27. The ophthalmic component of claim 26, wherein the lens comprises a refractive surface approximating that of an unapplanated cornea.

28. The ophthalmic component of claim 24, wherein the lens, prism, or both, are formed on one surface of the ophthalmic component.

29. A system, comprising:

an applanator configured to controllably applanate at least a portion of the ocular globe of a subject,

a first image collector configured to collect light reflected from an intraocular blood vessel of the subject; and

an illumination train configured to direct light through an ophthalmic component to the intraocular blood vessel of the subject and to direct light reflected from the intraocular blood vessel to the image collector.

the system being configured to, during operation, record retinal fundus images, score features of the optic disc using image processing algorithms, or both,

the system being configured to compare feature scores to a database of images so as to grade papilledma, if present, according the Modified Frisé

n Scale.

30. A method of assessing the intracranial pressure of a subject, comprising:

estimating intracranial pressure by combining an assessment of the level of papilledema, if any, present in the subject with one or more of a blood velocity of the subject, a blood vessel pressure of the subject, a tissue thickness of the subject, a tissue contour of the subject, or any combination thereof.

31. The method of claim 30, wherein the tissue thickness comprises the thickness of the retinal nerve fiber layer, the thickness of the prelaminar optic nerve head tissue, or any combination thereof.