Flexible Eye Insert and Glucose Measuring System

• US 20120259188A1
• Filed: 03/30/2012
• Published: 10/11/2012
• Est. Priority Date: 04/08/2011
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Besling, Willem Frederik Adrianus
• Granted Patent: US 9,737,245 B2
• Time in Patent Office: Days
• US Class Current: 600/319
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14507 specially adapted for measuring characteristics of body fluids other than blood devices for taking samples of body liquids A61B10/0045
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/6821 Eye
• CPC Class Codes: A61F 9/0017 implantable in, or in contact with, the eye, e.g. ocular inserts
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation

Abstract

Disclosed is a flexible insert (100) for placement on the human eye, comprising a light source (110) in said insert such that light emitted from the light source is shielded from the human eye upon correct placement of the insert on the human eye, a light-responsive material (120) placed in the light path of the light source, said light-responsive material emitting light upon stimulation by the light from said light source, the intensity of said stimulated emission being sensitive to a chemical interaction of the light-sensitive material with an analyte of interest, a photodetector (130) for detecting the light emitted by the light-responsive material; and a transmitter (140) coupled to the photodetector for transmitting a photodetector reading. The insert may be used in conjunction with a reader for automated monitoring of an analyte of interest such as glucose in the tear fluid of its wearer.

Claims

1. An insert for placement on a human eye, comprising:

a light source in said insert such that light emitted from the light source is shielded from the human eye upon correct placement of the insert on the human eye, the light source having a light path;

a light-responsive material placed in the light path of the light source, said light-responsive material emitting light upon stimulation by the light from said light source, one of the intensity and the wavelength of said stimulated emission being proportional to a chemical interaction of the light-sensitive material with an analyte of interest;

a photodetector for detecting the light emitted by the light-responsive material; and

a transmitter coupled to the photodetector for transmitting a photodetector reading.

2. The insert of claim 1, further comprising an optical fiber arranged to guide collimated light from the light source to the light-responsive material.

3. The insert (100) of claim 1, wherein the insert further comprises:

a first flexible layer; and

a second flexible layer, and

wherein the light source, the light-responsive material, the photodetector and the transmitter are located between said flexible layers.

4. The insert of claim 1, wherein the photodetector comprises a plurality of sensing elements for a ratiometric detection of the emitted light.

5. The insert of claim 1, wherein at least one of a reflective and a refractive layer and interface is present between the light source and the flexible carrier to prevent light emitted by the light source from entering the human eye.

6. The insert of claim 5, wherein the light source is placed between the reflective layer and a further reflective layer opposite the reflective layer.

7. The insert of claim 1, wherein a light-sensitive surface of the photodetector is facing the human eye upon correct placement of the insert in the human eye.

8. The insert of claim 7, wherein the photodetector is placed adjacent to and in the proximity with the light source such that light coupled out of the light source substantially evades said light-sensitive surface.

9. The insert of claim 1, further comprising a color filter placed over the photodetector for filtering out the light emitted by the light source.

10. The insert of claim 1, further comprising:

a charge storage element for powering the light source, the photodetector and the transmitter, and an inductive coil or antenna in the perimeter of the insert, said coil or antenna being coupled to the charge storage element for recharging the charge storage element upon exposure to electromagnetic radiation.

11. The insert of claim 1, wherein the light source is a light emitting diode, the light emitting diode further comprising a calibration circuit for measuring a junction temperature of the light emitting diode and for controlling at least one of a drive current and a forward voltage of said light emitting diode in response to said junction temperature measurement.

12. The insert of claim 1, wherein the analyte of interest is glucose.

13. The insert of claim 12, wherein the light-responsive material is a boronic acid according to Formula I:

14. A glucose-monitoring system comprising the flexible insert of claim 1 and a receiver for receiving a signal transmitted by the transmitter of the flexible insert, wherein the receiver is adapted to translate a reading from the photodetector into a glucose level.

15. The glucose-monitoring system of claim 14, further comprising a holder for the flexible insert, said holder being adapted to recharge the energy storage element of the flexible insert.