MEMS device and method for delivery of therapeutic agents

• US 7,887,508 B2
• Filed: 03/14/2007
• Issued: 02/15/2011
• Est. Priority Date: 03/14/2006
• Status: Expired due to Fees

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Agrawal, Rajat, Meng, Ellis, Kuwahara, Kenrick, Shih, Jason, Rodger, Damien, Lo, Ronalee, Li, Po-Ying, Tai, Yu-Chong, Chen, Po-Jui, Humayun, Mark S.
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): FLICK, JASON E
• Application Number:
  US11/686,310
• Publication Number:
  US 20080039792A1
• Time in Patent Office: 1,434 Days
• Field of Search: 604/114
• US Class Current: 604/114
• CPC Class Codes: A61F 9/0017 implantable in, or in contact with, the eye, e.g. ocular inserts
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/0097 Micromachined devices; Microelectromechanical systems [MEMS]; Devices obtained by lithographic treatment of silicon; Devices comprising chips intradermal microneedle arrays A61K9/0021; MEMS in general B81B7/02
• CPC Class Codes: A61M 2005/14204 with gas-producing electrochemical cell
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/3507 with implanted devices, e.g. external control
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 2210/0612 Eyes
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/14593 the diaphragm being actuated by fluid pressure
• CPC Class Codes: A61M 5/155 pressurised by gas introduced into the reservoir
• CPC Class Codes: A61M 5/16877 Adjusting flow; Devices for setting a flow rate
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28
• CPC Class Codes: B81B 2201/058 Microfluidics not provided for in B81B2201/051 - B81B2201/054
• CPC Class Codes: B81C 1/00119 Arrangement of basic structures like cavities or channels, e.g. suitable for microfluidic systems
• CPC Class Codes: B81C 2201/019 Bonding or gluing multiple substrate layers
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/0088 Implanted devices
• CPC Class Codes: F16K 99/0001 : Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0005 : Lift valves
• CPC Class Codes: F16K 99/0034 : Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0057 : the fluid being the circulating fluid itself, e.g. check valves
• CPC Class Codes: Y10T 29/49236 : Fluid pump or compressor making

Abstract

Embodiments of an implantable device for delivering a therapeutic agent to a patient includes a reservoir configured to contain a liquid comprising the therapeutic agent and a cannula in fluid communication with the reservoir. The device and related methods may provide such features as constant-flow operation, an electrolytic mode of pumping, and/or wireless communication.

Claims

1. An implantable electrolytic pump comprising:

a drug chamber for containing a liquid to be administered;

a cannula in fluid communication with the chamber;

first and second electrodes and circuitry for activating the electrodes; and

a flexible membrane disposed above the electrodes, the membrane comprising a series of radially-concentric corrugations facilitating (a) expansion of the membrane from a substantially flat configuration to an inflated configuration with increases in pressure and (b) contraction of the membrane from the inflated configuration to the substantially flat configuration with decreases in pressure, activation of the electrodes causing creation of a gas within the chamber to thereby expand the membrane so that liquid is forced from the chamber into the cannula.

2. The pump of claim 1 wherein the electrodes and the membrane are contained within the chamber.

3. The pump of claim 1 further comprising a separate electrolysis chamber, adjacent to the drug chamber, for containing a working fluid sealed therein, the electrodes being disposed in the electrolysis chamber.

4. The pump of claim 1 wherein the membrane is parylene.

5. The pump of claim 1 wherein the first electrode and the second electrode are both planar.

6. The pump of claim 5 wherein the first electrode and the second electrode are interdigitated with one another.

7. The pump of claim 1 wherein the cannula comprises a flow regulator.

8. The pump of claim 7 wherein the flow regulator comprises a valve.

9. The pump of claim 1 further comprising a refill port, for facilitating refilling of the pump, in fluid communication with the drug chamber.

10. A method of delivering a therapeutic agent to a patient, the method comprising the steps of:

providing a pump comprising (i) a drug chamber containing a liquid to be administered, (ii) a cannula in fluid communication with the chamber, (iii) first and second electrodes, and (iv) a flexible membrane disposed above the electrodes, the membrane comprising a series of radially-concentric corrugations facilitating (a) expansion of the membrane from a substantially flat configuration to an inflated configuration with increases in pressure and (b) contraction of the membrane from the inflated configuration to the substantially flat configuration with decreases in pressure;

placing the cannula in fluid communication with the patient; and

energizing the electrodes to cause creation of a gas within the chamber to thereby expand the membrane so that liquid is forced from the chamber through the cannula and is administered to the patient.

11. The method of claim 10 wherein the electrodes and the membrane are contained within the chamber.

12. The method of claim 10 wherein the pump comprises a separate electrolysis chamber adjacent to the drug chamber and the electrodes are disposed in the electrolysis chamber, and further comprising the step of providing a working fluid in the electrolysis chamber, the step of energizing the electrodes causing the gas to be created within the electrolysis chamber.