System and methods for optical sensing and drug delivery using microneedles

• US 20080221408A1
• Filed: 03/09/2007
• Published: 09/11/2008
• Est. Priority Date: 03/09/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Hoarau, Carine, Li, Li, Campbell, Shannon E., Batchelder, Keith
• Granted Patent: US 8,560,059 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4839 combined with drug delivery

Abstract

The current techniques provide a system for monitoring a physiological parameter of a patient using microneedles that are coupled to an optical system, allowing spectroscopic measurements to be made immediately below the outer layer of the epidermis. In embodiments of the present invention, the results of the spectroscopic measurements are used to control the administration of a drug through an intravenous tube. In other embodiments, the microneedles may be coated with a drug for administration to the patient. In other embodiments, the microneedles may be mounted in a probe, wherein an actuator is used to move the needles into contact with the skin, and a drug delivery system is used to infuse the drug into the patient. A method for making needles is also provided.

Claims

1. An array of microneedles, comprising:

one or more microneedles, wherein at least one of the microneedles is optically transmissive.

2. The array of microneedles of claim 1 wherein at least one of the microneedles comprises a hollow portion.

3. The array of microneedles of claim 2 wherein the microneedles comprising the respective hollow portions are configured to inject a drug into a patient.

4. The array of microneedles of claim 1 wherein at least one of the microneedles comprises a continuous solid structure.

5. The array of microneedles of claim 4 wherein the microneedles comprising the respective solid structures are made from an optically transmissive material.

6. The array of microneedles claim 1 wherein at least one of the microneedles is configured to enhance the permeability of the epidermis of a patient.

7. The array of microneedles of claim 1 wherein at least one of the optically transmissive microneedles is coupled by one or more optical fibers to at least one of an optical emission device or an optical detection device.

8. The array of microneedles of claim 1 wherein the array is configured to be moved by an actuator unit.

9. The array of microneedles of claim 8 wherein the actuator unit is configured to enable motion control of the array accurate to about 10 micrometers or less.

10. The array of microneedles of claim 1 wherein one or more of the microneedles are coated with a drug.

11. A system for patient care, comprising:

a microneedle array comprising one or more microneedles, wherein at least one of the microneedles is optically transmissive, wherein at least one of the optically transmissive microneedles is in optical communication with an optical detection device; and

a control unit comprising a data analysis unit configured to receive a measurement signal generated by the optical detection device.

12. The system of claim 11 wherein at least one of the microneedles comprises a hollow portion suitable for fluid flow.

13. The system of claim 12 wherein the microneedles comprising the respective hollow portions are configured to inject a drug.

14. The system of claim 11 wherein at least one of the microneedles comprises a continuous solid structure.

15. The system of claim 14 wherein the microneedles comprising the respective solid structures are made from an optically transmissive material.

16. The system of claim 11 wherein at least one of the microneedles is configured to enhance the permeability of the epidermis of a patient.

17. The system of claim 11 wherein at least one of the microneedles is coated with a drug.

18. The system of claim 11 comprising a sensor head, the sensor head comprising an actuator unit configured to move the microneedle array.

19. The system of claim 18 wherein the actuator unit is configured to enable motion control accurate to about 10 micrometers or less.

20. A method for monitoring patient status, comprising:

placing a microneedle array comprising one or more microneedles on the epidermis of a patient, wherein at least one of the microneedles is in optical communication with an optical detection component; and

analyzing a signal obtained from the optical detection component to determine a physiological parameter of the patient.

21. The method of claim 20 comprising delivering a drug to a patient through an intravenous tube based on the results obtained from analyzing the physiological parameter.

22. The method of claim 20 comprising delivering a drug to the patient using one or more microneedles of the microneedle array configured to facilitate delivery of the drug.

23. The method of claim 22 wherein delivering the drug comprises increasing the permeability of the epidermis of the patient using the respective microneedles of the microneedle array.

24. The method of claim 22 wherein delivering the drug comprises injecting the drug through one or more microneedles configured to facilitate delivery of the drug.

25. The method of claim 22 wherein delivering the drug comprises using microneedles that have been coated with a drug.

26. The method of claim 20 comprising controlling the depth of the insertion of the microneedles of the microneedle array using an actuator.

27. The method of claim 20 wherein the physiological parameter comprises at least one of oxygen saturation, blood glucose level, a tissue hydration, an amount of a drug delivered into the patient, or combinations thereof.

28. A method for manufacturing a microneedle array, comprising:

forming one or more microneedles from an optically transmissive material; and

optically coupling at least one of the microneedles to least one of a photoemitter or a detector.

29. The method of claim 28 comprising applying a metal plating to the material after forming the one or more microneedles.

30. The method of claim 29 comprising etching away the metal plating at the tip of each of the one or more microneedles to expose a portion of the material.

31. The method of claim 30 comprising removing the substrate and material to form hollow microneedles.

32. The method of claim 28 comprising imposing a metal grid over the microneedles to isolate the microneedles from each other.

33. The method of claim 28, comprising:

mounting one or more microneedles in a probe.

34. The method of claim 28 comprising coating the microneedles with a drug.