SWEAT SIMULATION, COLLECTING AND SENSING SYSTEMS

• US 20150057515A1
• Filed: 04/03/2013
• Published: 02/26/2015
• Est. Priority Date: 04/04/2012
• Status: Active Grant

• Current Assignee: University of Cincinnati
• Original Assignee: University of Cincinnati
• Inventors: Heikenfeld, Jason C., Papautsky, Ian, Naik, Rajesh, Stone, Morley, Hagen, Joshua A, Hou, Linlin, Kelly-Loughnane, Nancy, Busbee, John, Wang, Xiao
• Granted Patent: US 11,460,430 B2
• Time in Patent Office: Days
• US Class Current: 600/346
• CPC Class Codes: A61B 10/0064 for taking sweat or sebum samples measuring sweat production A61B5/4266
• CPC Class Codes: A61B 10/0096 Casings for storing test samples A61B10/0038 and A61B10/0045 take precedence; preservation of living parts of the human or animal body A01N1/02; containers for retaining a material to be analysed B01L3/50; containers for enzymology or microbiology C12M1/16; swab-sampler being part of enzymology or microbiology container C12M1/30
• 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 5/14517 for sweat
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: B01L 2200/0621 Control of the sequence of chambers filled or emptied
• CPC Class Codes: B01L 2300/022 Transponder chips
• CPC Class Codes: B01L 2300/023 Sending and receiving of information, e.g. using bluetooth
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/069 Absorbents; Gels to retain a fluid
• CPC Class Codes: B01L 2300/0803 Disc shape
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2300/163 Biocompatibility
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 2400/086 using baffles or other fixed flow obstructions
• CPC Class Codes: B01L 3/5023 : with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: G01N 27/3273 : Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875
• CPC Class Codes: G01N 27/4145 : specially adapted for biomolecules, e.g. gate electrode with immobilised receptors

Abstract

Biological chemicals, potentially found in blood are measured by collecting sweat and determining the concentration or meaning of the selected chemical in sweat. The sweat can be collected using a time based, interval collector and analyzed using an external device. It can also be collected on a one time basis, using a flexible, chemical capacitor, or on a continuous basis using a chemical, field effect transducer.

Claims

1. A fluid sample collector comprising an aqueous fluid absorbing member;

a plurality of discrete fluid transporting paths, each path leading from said absorbing member to a separate collection member;

each path having a separate time dependent flow restrictor, wherein each flow restrictor allows fluid flow into one of said collection members at a different time;

a flow bridge in each of said paths effective to stop fluid flow from one of said absorbing member to a corresponding collection member.

2. Sample collector claimed in claim 1 wherein said absorbing member in a fibrous pad.

3. The sample collector claimed in claim 1 wherein said flow restrictors are each water soluble polymer films.

4. The sample collector claimed in claim 1 wherein said bridge is a water soluble polymer fibrous thread.

5. The sample collector claimed in claim 3 wherein each of said water soluble polymer films has a different solubility.

6. The sample collector claimed in claim 5 wherein said polymer film is polyethylene oxide.

7. The sample collector claimed in claim 1 wherein said flow restrictors are physical obstacles.

8. The sample collector claimed in claim 7 wherein said physical obstacles comprise a flow paths having different widths.

9. The sample collector claimed in claim 1 wherein each of said paths extends radially outwardly from said collection member.

10. A method of collecting an aqueous sample over time comprising collecting a sample at a central collection member and allowing said sample to flow to a plurality of separate collection members, collecting sample portions in each of said collection members at different times.

11. The method claimed in claim 10 comprising controlling the flow rate of said liquid along each of a plurality of flow paths to said separate collection members whereby each sample portion reaches said respective collection members at different times.

12. The method claimed in claim 11 further comprising discontinuing flow into said collection member after a volume of sample has flowed into said collection member.

13. The method claimed in claim 12, wherein said discontinuing flow is effected by physically interrupting said flow paths.

14. The method claimed in claim 13, wherein said flow path is interrupted by dissolving said flow path.

15. The method claimed in claim 10, wherein the samples in each of said collection members are independently analyzed.

16. The method found in claim 15 wherein said sample is sweat and said sample is collected from the skin of an individual.

17. A method of determining a concentration of a first chemical in sweat comprising collecting a volume of sweat;

determining the amount of said first chemical in said volume of sweat without determining the volume of said sweat;

determining the amount of a second chemical in said sweat in said volume of sweat to establish a ratio of said first chemical to said second chemical.

18. The method claimed in claim 17 wherein said first and second chemicals are selected from the group consisting of electrolytes, glucose, lactate, pro-inflammatory cytokines, anti-inflammatory cytokines, catecholamines, neuropeptides and proteins.

19. An apparatus to detect biological chemicals in sweat comprising a reservoir containing a cholinergic agonist adjacent a biological chemical sensor, said sensor having one or more functional groups in an assay region reactive with one or more biological chemicals.

20. The apparatus claimed in claim 19 further comprising a fastener, adapted to hold said sensor against skin of an individual.

21. The apparatus claimed in claim 19 having an iontophoresis electrode adjacent said reservoir.

22. The apparatus claimed in claim 21 wherein said cholinergic agent is pilocarpine and said reservoir is between said electrochemical sensor and said electrode.

23. The apparatus claimed in claim 24 wherein said electrochemical sensor includes a base layer having a plurality of holes permitting pilocarpine to migrate through said base layer.

24. The apparatus claimed in claim 21 wherein said biological chemical sensor is selected from the group consisting of chemical capacitor, chemical field effect transistor, ion-selective electrode, chemical electrical impedance spectroscope and electrochemical potentiostat.

25. A continuous body chemical monitor comprising;

a sweat absorption member having a collection portion, a transfer portion and an removal portion, wherein said transport portion has a fluid transport capacity less than said collection portion and less than said removal portion;

a sensor on a water impervious base said sensor positioned on said transfer portion.

26. The monitor claimed in claim 25 wherein said transport portion comprises a plurality of narrow strips, extending from said collection portion to said removal portion.

27. The monitor claimed in claim 25, further comprising a water porous adhesive layer, covering said collection portion.

28. The monitor claimed in claim 25 further comprising a transmitter adapted to transmit data from said sensor.

29. The monitor claimed in claim 28, further comprising a receiver member, adaptive to receive a signal from an external device which activates said transmitter.

30. The monitor claimed in claim 25, wherein said sensor is connected to an RFID circuit.

31. The monitor claimed in claim 30 wherein said sensor is part of a chemical, field effect transducer.

32. The monitor claimed in claim 25 further comprising a cholinergic agent and an iontophorsis electrode.

38. The monitor claimed in claim 25 wherein said sensor is one or more ion-selective electrodes effective to monitor concentrations of one or more electrolytes.

33. A method of measuring biomolecules in sweat comprising positioning a sweat collection pad on the skin of an individual, whereby sweat from said individual is collected by said collection pad;

directing said sweat through said collection pad along a transport portion adjacent to a biological chemical sensor, measuring biomolecules in said sweat with said electrical sensor;

directing said sweat from said collection pad through removal portion away from said electrical sensor and away from said collection pad, whereby additional sweat is collected by said collection pad and said additional sweat is analyzed for said biomarkers by said electrical sensor.

34. The method claimed in claim 33 further comprising inducing sweating by contacting said skin with a cholinergic agent.

35. The method claimed in claim 33 further comprising collecting data generated by said method using an external device.

36. The method claimed in claim 33, a plurality of biomolecules is detected.

37. The method claimed in claim 33 where solutes in sweat are transported across said biological chemical sensor by fluid flow and not in the opposite direction by diffusion.