Miniaturized electrothermal flow induced infusion pump

• US 20070110625A1
• Filed: 09/06/2006
• Published: 05/17/2007
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: SynVivo, Inc.
• Original Assignee: CFD Research Corporation
• Inventors: Wang, Yi, Wang, Guiren, Krishnamoorthy, Sivaramakrishnan, Feng, Jianjun
• Granted Patent: US 9,283,597 B2
• Time in Patent Office: Days
• US Class Current: 422/99
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: B01F 33/3033 using heat to mix or move the fluids
• CPC Class Codes: B01F 33/3034 using induced convection or movement in the mixture to mix or move the fluids without mechanical means, e.g. thermodynamic instability, strong gradients, etc.
• CPC Class Codes: B01L 2300/1833 using electrical currents in the sample itself
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0442 thermal energy, e.g. vaporisation, bubble jet
• CPC Class Codes: B01L 2400/0493 Specific techniques used
• CPC Class Codes: B01L 2400/0496 Travelling waves, e.g. in combination with electrical or acoustic forces
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B08B 7/0064 by temperature changes
• CPC Class Codes: B08B 9/00 Cleaning hollow articles by methods or apparatus specially adapted thereto B08B6/00 takes precedence
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F04B 19/24 Pumping by heat expansion of pumped fluid
• CPC Class Codes: G01N 2030/0035 electrical field
• CPC Class Codes: G01N 2030/0065 Dielectric FFF, i.e. opposing forces dominate hydrodynamic lift forces and steric effects

Abstract

A micropump that pumps liquid using electrothermally-induced flow is described, along with a corresponding self-regulating pump and infusion pump. The micropump has applications in microfluidic systems such as biochips. The self-regulating infusion pump is useful for the administration of large and small volumes of liquids such as drugs to patients and can be designed for a wide range of flow rates by combining multiple micropumps in one infusion pump system.

Claims

1. An electrothermal flow pump comprising:

a) a pumping chamber comprising walls that define a fluid-filled volume in the chamber,

b) at least one inlet to and at least one outlet from the pumping chamber,

c) at least one set of at least three elongated electrodes arranged in parallel and separated by a regular gap distance in one wall or opposing walls of the pumping chamber,

d) a power supply electrically coupled to each of the electrodes of the at least one set of electrodes with a phase shift of 3π

/n where n is the number of electrodes in the at least one set of electrodes to produce electrothermal flow that moves fluid within the pumping chamber in a direction perpendicular to the elongated electrodes.

2. The electrothermal flow pump of claim 1 in which the at least one set of electrodes comprises 4 electrodes, 2 electrodes each on opposing walls of the pumping chamber.

3. The electrothermal flow pump of claim 1 in which the pumping chamber comprises at least two sets of four electrodes located on opposing walls of the pumping chamber.

4. The electrothermal flow pump of claim 3 in which the electrodes of the two sets are aligned with respect to one another.

5. A self-regulating electrothermal flow drug infusion pump comprising an electrothermal flow pump, a flow rate sensor, and a controller wherein:

a) the electrothermal flow pump comprises;

(i) a plurality of ETF micropumps in liquid communication with one another and

(ii) a conduit for delivering a liquid pumped from the plurality of ETF micropumps to a conduit outlet placed within a patient;

b) the flow rate sensor is a device that measures the flow rate of liquid through the conduit; and

c) the controller comprises a fluid reservoir, a microprocessor, and a power supply wherein;

(i) the microprocessor receives flow rate information from the flow sensor and controls electrode activation and

(ii) the fluid reservoir is in liquid communication with the plurality of ETF micropumps.

6. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the plurality of micropumps are arranged in series and in parallel.

7. The self-regulating electrothermal flow drug infusion pump of claim 6 comprising at least 20 ETF micropumps.

8. The self-regulating traveling-wave electrothermal flow drug infusion pump of claim 5 wherein the flow rate sensor is a laser-induced fluorescence photobleaching anemometer or impedance anamometer.

9. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the fluid reservoir comprises a plurality of compartments, each containing a different drug or concentration of drug.

10. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the pump produces a maximum flow rate of between 0.5 mL/hr and 180 mL/min.

11. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the electrothermal flow pump and controller are located outside the body of the patient and the conduit outlet is located inside the patient.

12. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the electrothermal flow pump and conduit are located inside the body of the patient.

13. The self-regulating electrothermal flow drug infusion pump of claim 5 wherein the liquid comprises a drug and the conduit is placed within a patient for subcutaneous, intradermal, intravenous, intramuscular, intrathecal, intracranial, itraperitoneal, or intraocular drug delivery.