Optical sensor for bandage type monitoring device

• US 20160345872A1
• Filed: 06/01/2015
• Published: 12/01/2016
• Est. Priority Date: 06/01/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Inventors: Wasson, Jaclyn Leverett, Biederman, William James, Liu, Zenghe, Otis, Brian
• Granted Patent: US 10,292,630 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• 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 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6847 mounted on an invasive device
• CPC Class Codes: A61B 5/685 Microneedles
• CPC Class Codes: A61B 5/688 using adhesives

Abstract

A flexible, body-mountable analyte sensing device includes a flexible substrate configured for mounting to skin of a living body. The sensing device additionally includes optical fiber attached to the flexible substrate and configured to penetrate the skin such that an analyte-sensitive substance disposed on the end of the optical fiber can detect an analyte in interstitial fluid. A color, fluorescence intensity, or other optical property of the analyte-sensitive substance is related to the concentration or other property of the analyte. Light reflected, scattered, fluorescently emitted, or otherwise emitted from the analyte-sensitive substance is transmitted via the optical fiber and detected by a light sensor on the flexible substrate. Such emitted light can be emitted in response to illumination of the analyte-sensitive substance via the optical fiber. The sensing device is configured to wirelessly indicate detected concentrations or other information about the analyte in the interstitial fluid.

Claims

1. A body-mountable device comprising:

a flexible substrate, wherein the flexible substrate is configured to be mounted to a skin surface;

a sensor probe, wherein a first end of the sensor probe is attached to the flexible substrate, wherein a second end of the sensor probe is configured to extend beneath the skin surface to contact interstitial fluid, and wherein the sensor probe comprises an optical fiber extending from the first end of the sensor probe to the second end of the sensor probe;

an analyte-sensitive substance, wherein the analyte-sensitive substance is disposed at the second end of the sensor probe, and wherein the analyte-sensitive substance has an optical property affected by an analyte in the interstitial fluid;

a light detector; and

one or more electronic components disposed on the flexible substrate, wherein the one or more electronic components are configured to (i) operate the light detector to detect, via the optical fiber, a property of light emitted from the analyte-sensitive substance and (ii) indicate data related to the detected property of the emitted light.

2. The body-mountable device of claim 1, further comprising an adhesive layer disposed on the flexible substrate, wherein the adhesive layer is configured to adhere the flexible substrate to the skin surface.

3. The body-mountable device of claim 1, wherein the sensor probe has a length between approximately 2 millimeters and approximately 6 millimeters.

4. The body-mountable device of claim 1, further comprising an antenna disposed on the flexible substrate, wherein the electronic components are configured to indicate data related to the detected property of the emitted light to an external device using the antenna.

5. The body-mountable device of claim 1, wherein the one or more electronic components include a memory configured to store the data related to the detected property of the emitted light.

6. The body-mountable device of claim 1, further comprising a light emitter, wherein the one or more electronic components are further configured to (iii) operate the light emitter to illuminate, via the optical fiber, the analyte-sensitive substance, and wherein the light emitted from the analyte-sensitive substance is emitted responsive to illumination by the light emitter.

7. The body-mountable device of claim 6, wherein the analyte-sensitive substance comprises a fluorophore, and wherein the detected property of the emitted light is a property of the fluorescence of the fluorophore.

8. The body-mountable device of claim 1, wherein the sensor probe further comprises a further optical fiber extending from the first end of the sensor probe to the second end of the sensor probe, and further comprising:

an optical substance, wherein the optical substance is disposed at the second end of the sensor probe, and wherein the optical substance has an optical property that is less strongly affected by the analyte in the interstitial fluid than the optical property of the analyte-sensitive substance; and

a further light detector, wherein the one or more electronic components are further configured to (iii) operate further the light detector to detect, via the further optical fiber, a property of light emitted from the optical substance.

9. The body-mountable device of claim 1, wherein the analyte-sensitive substance is disposed within a polymer, wherein the polymer is permeable to the analyte.

10. The body-mountable device of claim 9, wherein the polymer comprises 2-hydroxyethyl methacrylate units.

11. The body-mountable device of claim 1, wherein the analyte is glucose and wherein the analyte-sensitive substance comprises a boronic acid moiety.

12. A method comprising:

operating a body-mountable device, wherein the body-mountable device comprises;

a flexible substrate, wherein the flexible substrate is configured to be mounted to a skin surface;

a sensor probe, wherein a first end of the sensor probe is attached to the flexible substrate, wherein a second end of the sensor probe is configured to extend beneath the skin surface to contact interstitial fluid, and wherein the sensor probe comprises an optical fiber extending from the first end of the sensor probe to the second end of the sensor probe;

an analyte-sensitive substance, wherein the analyte-sensitive substance is disposed at the second end of the sensor probe, and wherein the analyte-sensitive substance has an optical property affected by an analyte in the interstitial fluid;

a light detector; and

one or more electronic components disposed on the flexible substrate;

wherein the operating comprises;

obtaining, by the one more electronic components operating the light detector to detect light emitted from the analyte-sensitive substance via the optical fiber, data related to a property of the emitted light; and

indicating, by the one or more electronic components, the data related to the property of the emitted light.

13. The method of claim 12, wherein the body-mountable device further comprises a light emitter, and wherein the operating further comprises operating the light emitter to illuminate, via the optical fiber, the analyte-sensitive substance, and wherein the light received by the light detector from the analyte-sensitive substance is emitted from the analyte-sensitive substance responsive to illumination by the light emitter.

14. The method of claim 12, wherein the body-mountable device further comprises an antenna disposed on the flexible substrate, and wherein indicating, by the one or more electronic components, the data related to the property of the emitted light comprises:

communicating the data related to the property of the emitted light via the antenna to an external device.

15. The method of claim 12, wherein the one or more electronic components include a memory, wherein the operating further comprises:

storing the data related to the property of the emitted light in the memory.

16. The method of claim 12, further comprising:

coupling the sensor probe to a needle; and

inserting the needle with the sensor probe coupled thereto into the skin surface such that the analyte-sensitive substance is in a position to contact interstitial fluid.

17. The method of claim 16, further comprising:

retracting the needle from the skin surface such that the analyte-sensitive substance remains in the position to contact interstitial fluid.

18. The method of claim 12, wherein the sensor probe further comprises a further optical fiber extending from the first end of the sensor probe to the second end of the sensor probe, wherein the body-mountable device further comprises:

(a) an optical substance, wherein the optical substance is disposed at the second end of the sensor probe, and wherein the optical substance has an optical property that is less strongly affected by the analyte in the interstitial fluid than the optical property of the analyte-sensitive substance and (b) a further light detector, wherein the operating further comprises obtaining, by the one more electronic components operating the further light detector to receive further light from the optical substance via the further optical fiber, data related to a property of the received further light.

19. A method comprising:

depositing a solution proximate to a first end of an optical fiber, wherein the solution comprises an analyte-sensitive substance and monomer units; and

polymerizing the solution to form a polymer, wherein the analyte-sensitive substance is disposed within the formed polymer, wherein the formed polymer is permeable to the analyte, and wherein polymerizing the solution comprises transmitting light via the optical fiber to expose the solution to the transmitted light.

20. The method of claim 19, wherein the monomer units comprise 2-hydroxyethyl methacrylate.