Miniaturized electrothermal flow induced infusion pump
Inventors
Krishnamoorthy, Sivaramakrishnan • WANG, GUIREN • Feng, Jianjun • Wang, Yi
Assignees
Publication Number
US-9878090-B2
Publication Date
2018-01-30
Expiration Date
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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 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. The micropump uses electrode sequences on opposing surfaces of a flow chamber that are staggered with respect to each other. The opposing surfaces include staggered electrodes that have the same phase and same electrode sequence. As such electrodes with the same phase are staggered and not eclipsed.
Core Innovation
The invention is a micropump that pumps liquid using electrothermally-induced flow, together with a corresponding self-regulating pump and infusion pump, and has applications in microfluidic systems such as biochips. The self-regulating infusion pump is described as useful for 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.
The micropump employs electrode sequences on opposing surfaces of a flow chamber that are staggered with respect to each other, where opposing surfaces include staggered electrodes that have the same phase and same electrode sequence so that electrodes with the same phase are staggered and not eclipsed. The ETF micropump minimally comprises a pumping chamber containing a fluid to be pumped, an inlet and an outlet, and sets of phase-shifted, parallel elongate electrodes arranged to produce a traveling-wave electrothermal flow (tw-ETF) of fluid within the pumping chamber.
The invention addresses the need for controlled infusion by providing a self-regulating micropump that monitors flow rates using techniques such as Laser-Induced Fluorescence Photobleaching Anemometry (LIFPA) or Flow Induced Differential Electrochemical Impedance Spectroscopy (FI-DEIS) and couples flow measurements to a pump controller to maintain a constant or pre-programmed flow rate. The use of electrothermally-induced flow is described as enabling higher flow rates and head pressures compared to existing electrokinetic pumps due to the scaling of ETF with applied voltage.
Claims Coverage
This section summarizes 2 independent claims and 9 main inventive features extracted from those claims.
Pumping chamber with opposed top and bottom walls and end inlet and outlet
A pumping chamber having an internal volume with an elongated length along a longitudinal axis defined by a top wall and a bottom wall opposite the top wall, with a fluid inlet at a first end of the pumping chamber and a fluid outlet at a second end opposite the first end.
Three-phase electrode sets on the top wall
One or more first electrode sets of three sequentially arranged parallel elongate electrodes extending laterally across the top wall, each set having a first, second, and third elongate electrode arranged in sequence with a phase shift of 2π/3 from the first to the second to the third electrode.
Three-phase electrode sets on the bottom wall
One or more second electrode sets of three sequentially arranged parallel elongate electrodes extending laterally across the bottom wall, each set having a first, second, and third elongate electrode arranged in sequence with a phase shift of 2π/3 from the first to the second to the third electrode.
Staggered registration of corresponding electrodes
The first, second, and third elongate electrodes of the top electrode sets are staggered with respect to the corresponding first, second, and third elongate electrodes of the bottom electrode sets, respectively.
Electrical leads coupling electrodes by phase
Top electrical leads electrically coupled with the first, second, and third elongate electrodes of the top electrode sets and bottom electrical leads electrically coupled with the first, second, and third elongate electrodes of the bottom electrode sets so that electrodes of the same phase are connected to corresponding leads.
Power supply providing phase-shifted excitation to induce ETF
At least one power supply electrically coupled with the top and bottom electrical leads so as to provide the phase shift of 2π/3 from the first to the second to the third electrodes of each of the top and bottom electrode sets to pump liquid with electrothermally-induced flow.
Plurality of ETF pumping devices forming a system
A plurality of the ETF pumping devices of the described device are included as components of a larger pumping system.
Fluid reservoir and fluid conduit coupling pumps to an outlet
A fluid reservoir fluidically coupled to each of the fluid inlets of the ETF pumping devices and a fluid conduit having a conduit inlet coupled to each of the fluid outlets and an opposite conduit outlet.
Flow sensor and controller configured to control flow rate
A flow rate sensor fluidically coupled to the conduit outlet and a controller having a microprocessor operably coupled to the flow sensor and the power supply, the microprocessor configured to control flow rate of fluid through the fluid conduit.
The independent claims principally cover an ETF pumping device with phase-shifted three-electrode sets on opposing staggered walls electrically coupled to leads and a power supply to induce electrothermal flow, and a self-regulating system that combines multiple such ETF pumping devices with a reservoir, conduit, flow sensor, and controller to control fluid flow.
Stated Advantages
Enables administration of large and small volumes of liquids such as drugs to patients by a self-regulating infusion pump.
Can be designed for a wide range of flow rates by combining multiple micropumps in one infusion pump system.
Provides mean pumping velocities that increase with the fourth power of the applied voltage, enabling higher flow rates and head pressures than existing electrokinetic pumps.
Allows monitoring of flow rates and coupling of flow measurements to a pump controller to maintain constant flow or deliver pre-programmed flow rate patterns.
Useful for miniaturized, self-regulating pumping in microfluidic systems and biochips.
Documented Applications
Drug delivery by infusion and self-regulated electrothermal flow (ETF) drug infusion pumping.
Controlled delivery of antibiotics, antiviral agents, anesthesia, chemotherapy, total parenteral nutrition (TPN), and patient-controlled analgesia.
Controlled delivery of concentrated drugs over extended periods to ambulatory patients and controlled infusion of high volumes of fluids.
Auto-controlled pumping in microfluidic systems and biochips.
Use with reservoirs containing one or more drug compartments for programmed release of different drugs or drug combinations.
Delivery configured for placement at subcutaneous, intradermal, intravenous, intramuscular, intrathecal, intracranial, intraperitoneal, or intraocular sites.
Use with flow rate sensing methods such as Laser-Induced Fluorescence Photobleaching Anemometry (LIFPA) or flow induced differential electrochemical impedance spectroscopy (FI-DEIS) for feedback control.
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