Devices for integrated, repeated, prolonged, and/or reliable sweat stimulation and biosensing

• US 10,368,847 B2
• Filed: 03/29/2018
• Issued: 08/06/2019
• Est. Priority Date: 10/18/2013
• Status: Active Grant

• Current Assignee: University of Cincinnati
• Original Assignee: University of Cincinnati
• Inventors: Heikenfeld, Jason Charles, Sonner, Zachary Cole
• Primary Examiner(s): Stigell, Theodore J
• Application Number:
  US15/939,429
• Publication Number:
  US 20180214137A1
• Time in Patent Office: 495 Days
• CPC Class Codes: A61B 10/0064 for taking sweat or sebum samples measuring sweat production A61B5/4266
• CPC Class Codes: A61B 2010/0009 Testing for drug or alcohol abuse
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/168 Fluid filled sensor housings
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/14521 using means for promoting sweat production, e.g. heating the skin measuring sweat secretion A61B5/4266
• CPC Class Codes: A61B 5/1491 Heated applicators
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/4266 sweat secretion
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61M 2202/092 Sweat glands
• CPC Class Codes: A61N 1/325 for iontophoresis, i.e. transfer of media in ionic state by an electromotoric force into the body electrodes for external use A61N1/0428

Abstract

A sweat sensing device includes a plurality of sweat collection pads communicating with a sensor. Each of the pads is activated by a timing circuit which allows one or more of the pads to be activated at a selected time and subsequent deactivated after a defined period of time. This allows for selective collection of sweat from a plurality of pads over a prolonged period of time. An impedance measuring circuit can be employed to determine if one or more of the pads becomes disconnected, in order to avoid irritation. Further, the devices can use a common microfluidic device which both transports sweat activating substance, such as pilocarpine, to the surface of the skin and directs sweat away from the skin to a sensing device.

Claims

1. A sweat stimulating and transport device capable of both transporting sweat away from a device wearer'"'"'s skin and transporting sweat stimulants to the skin comprising:

one or more sweat stimulating components;

one or more sensors configured to measure a characteristic of an analyte in a sweat sample;

one or more additional components, wherein the one or more additional component is one of a sweat sample transporter, a sweat stimulant transporter, and a shared microfluidic component configured to transport both the sweat sample and a sweat stimulant; and

a selective membrane separating the one or more sweat stimulating components from the one or more sensors and the one or more additional components.

2. The device of claim 1, wherein the one or more sweat stimulating components further comprises one or more iontophoresis electrodes and one or more counter electrodes, and transport of the sweat stimulant is at least partially achieved by iontophoresis.

3. The device of claim 2, wherein an electric field is generated between the one or more iontophoresis electrodes and the one or more counter electrodes to drive said sweat stimulant into the skin.

4. The device of claim 2, wherein the the one or more iontophoresis electrodes is configured to drive an electric field beneath said one or more sensors to bring the sweat stimulant into the skin beneath said one or more sensors.

5. The device of claim 2, wherein the one or more sweat stimulating components further comprises a reservoir, and wherein the selective membrane is configured to allow diffusion of said sweat stimulant out of the reservoir while limiting diffusion of substances into the reservoir.

6. The device of claim 1, wherein the one or more sweat stimulating components further comprises a reservoir, and wherein the at one or more additional components is separated from the reservoir by the selective membrane.

7. The device of claim 1, wherein the one or more additional components comprises the shared microfluidic component, and the one or more sensors is in fluidic contact with the shared microfluidic component.

8. The device of claim 1, wherein the one or more sweat stimulating components further comprises a reservoir containing the sweat stimulant, and wherein the selective membrane limits flow of fluid or diffusion of solutes between the one or more additional components and the reservoir.

9. The device of claim 1, wherein the selective membrane has a higher porosity to the sweat stimulant than one or more sweat solutes to be sensed.

10. The device of claim 1, wherein the selective membrane has a lower electrical impedance than an electrical impedance of the skin.

11. The device of claim 1, wherein said additional component is configurable on the skin adjacent to a location wherein an amount of sweat stimulant contacts the skin.

12. A device comprising:

one or more elements chosen from the following;

a sweat stimulant, a substance to reduce irritation, inflammation, or pain, and a sweat reducing substance;

a sensor;

one or more additional components, wherein the one or more additional component is at least one of a sweat transporter and a shared microfluidic component configured to transport both a sweat sample and the one or more elements; and

a selective membrane separating the one or more elements from the one or more additional components.

13. The device of claim 12, further comprising one or more iontophoresis electrodes and one or more counter electrodes, and the one or more elements is delivered iontophoretically.

14. The device of claim 13, wherein the one or more elements comprises both the substance to reduce irritation, inflammation, or pain and the sweat stimulant, and the one or more elements are delivered iontophoretically using a single voltage polarity.