MONITORING METHOD AND/OR APPARATUS

• US 20090069651A1
• Filed: 08/08/2008
• Published: 03/12/2009
• Est. Priority Date: 04/18/2003
• Status: Abandoned Application

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Zimmermann, Stefan, Liepmann, Dorian, Pisano, Albert, Stoeber, Boris
• Application Number:
  US12/188,918
• Publication Number:
  US 20090069651A1
• Time in Patent Office: Days
• US Class Current: 600/316
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14525 using microdialysis
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase

Abstract

A method and apparatus for substance monitoring. One application is an easy to handle continuous glucose monitor using a group of hollow out-of-plane silicon microneedles to sample substances in interstitial fluid from the epidermal skin layer. The glucose of the interstitial fluid permeates a dialysis membrane and reaches a sensor. Using MEMS technology, for example, allows well-established batch fabrication at low cost.

Claims

1. A method of monitoring one or more substances of interest comprising:

applying a plurality of out-of-plane microneedles to a surface of an internal region, said microneedles long enough to prestress a region of the surface at a needle lumen;

applying high pressure to a small local surface region through said microneedles to cause rupture of the cell matrix to open a connection between fluids inside the needle lumen and bodily fluids underneath the broken skin layer; and

using said connection to sample one or more substances of interest at and/or just below said surface.

2. The method of claim 1 further wherein:

said microneedles comprising one or more membranes on a side opposite a side applied to said surface such that said membrane is not placed under said surface;

said membrane separating in said microneedles from a dialysis material;

such that dialysis occurs outside of said internal region.

3. The method of claim 2 further wherein:

said one or more dialysis membranes comprise a large total membrane surface that can remain outside of said internal region.

6. The method of claim 1 further wherein:

said surface is a surface of a living organism or part or organ thereof.

7. The method of claim 1 further wherein:

a plurality of said microneedles are pre-filled with a fluid before said applying.

8. The method of claim 1 further comprising:

treating glucose disorders by applying a plurality of out-of-plane microneedles to the skin with a dialysis membrane remaining outside the skin thereby allowing for continuous glucose monitoring.

9. The method of claim 8 further comprising:

fixing a detecting substance useful in determining glucose levels on an opposite side of said dialysis membrane from said needles;

wherein said fixing is accomplished by placing a polymer-detecting substance solution at an opposite side of said membrane after higher temperature fabrication and/or assembly steps of said microneedles have been performed.

4-5. -5. (canceled)

10. A device for monitoring a substance of interest comprising:

a group of out-of-plane microneedles;

a dialysis membrane proximal to a non-insertive side of said group;

a dialysis fluid in contact with a second surface of said dialysis membrane opposite said group;

such that when said group is pressed against a surface of interest, said substance of interest within and/or behind said surface of interest can come in contact with a second surface of said dialysis membrane, allowing one or more substances of interest to pass into said dialysis fluid.

11. The device according to claim 10 further comprising:

one or more sensors in contact with said dialysis fluid for measuring and/or detecting one or more substances of interest.

12. The device according to claim 11 further comprising:

an area for holding calibration fluid; and

a valve between said calibration fluid and said dialysis fluid.

13. The device according to claim 10 further comprising:

at least 50 microneedles in said group.

said microneedles are between about 100 micrometers and about 300 micrometers long.

said microneedles are between about 180 micrometers and about 220 micrometers long.

said microneedles are constructed of one or more of a metallic material;

plastic;

silicon;

a semiconductor material;

said membrane comprises a polymer and/or gel and/or porous poly-Si;

wherein one or more enzymes integrated into said membrane.

14-28. -28. (canceled)

29. A method of in-device patterning of a temperature sensitive substance in an integrated system comprising:

performing one or more high temperature steps;

placing a solution of said temperature sensitive substance and a polymer in desired regions of said integrated system; and

gelling and/or immobilizing and/or polymerizing said solution in regions of interest using electromagnetic energy.

30. The method of claim 29 further comprising:

using a mask to define areas where said solution will not be immobolized and/or polymerized and/or gelled; and

rinsing away remaining solution.

31. The method of claim 29 further wherein:

said temperature sensitive substance comprises

an enzyme.

said electromagnetic energy comprises UV light.

said polymerizing comprises crosslinking said polymer.

34. The method of claim 29 further comprising:

performing one or more high temperature steps including a step of bonding a transparent or semi-transparent material on said system;

placing a solution of said temperature sensitive substance and a polymer in desired regions of said integrated system such that said solution in part resides in areas between said transparent or semi-transparent material and other components of said system;

hardening said solution in regions of interest using electromagnetic energy that can pass through said transparent or semi-transparent material; and

rinsing unhardened portions of said solution.

35. The method of claim 34 further wherein:

said bonding is anodic bonding;

said hardening comprises crosslinking said polymer;

36. The method of claim 34 further wherein:

said polymer comprises PVA-SbQ;

said electromagnetic energy comprises UV light;

said UV light comprises light of about 365 nm or 900 mJ/cm2;

\

37. The method of claim 34 further wherein:

using a mask to define regions of said hardening;

such that said temperature sensitive substance becomes entrapped in locally formed gel regions; and

said rinsing comprises rinsing unlinked solution.

32-33. -33. (canceled)

38-39. -39. (canceled)