DRUG-DELIVERY PUMP WITH INTELLIGENT CONTROL

• US 20140094771A1
• Filed: 09/24/2013
• Published: 04/03/2014
• Est. Priority Date: 05/08/2008
• Status: Active Grant

• Current Assignee: MiniPumps, LLC
• Original Assignee: MiniPumps, LLC
• Inventors: Li, Po-Ying, Li, Shengtao, Lee, Jonathan K., Ryan, Patrick, Lai, Alice, Caffey, Sean, Humayun, Mark S.
• Granted Patent: US 9,333,297 B2
• Time in Patent Office: Days
• US Class Current: 604/506
• CPC Class Codes: A61M 2005/14204 with gas-producing electrochemical cell
• CPC Class Codes: A61M 2005/14252 with needle insertion means
• CPC Class Codes: A61M 2005/14513 with secondary fluid driving or regulating the infusion
• CPC Class Codes: A61M 2205/0222 Materials for reducing friction
• CPC Class Codes: A61M 2205/0238 the material being a coating or protective layer
• CPC Class Codes: A61M 2205/3331 Pressure; Flow
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3341 stabilising pressure or flow to avoid excessive variation
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 2205/8231 using electrochemical gas generating device for the driving gas
• CPC Class Codes: A61M 2205/8293 Solar
• CPC Class Codes: A61M 2210/0612 Eyes
• CPC Class Codes: A61M 2210/0693 Brain, cerebrum
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/14526 the piston being actuated by fluid pressure
• CPC Class Codes: A61M 5/14586 : pressurised by means of a flexible diaphragm
• CPC Class Codes: A61M 5/14593 : the diaphragm being actuated by fluid pressure
• CPC Class Codes: A61M 5/148 : flexible, e.g. independent bagsA61M5/155 takes precedence
• CPC Class Codes: A61M 5/155 : pressurised by gas introduced into the reservoir
• CPC Class Codes: A61M 5/16804 : Flow controllers
• CPC Class Codes: A61M 5/16809 : by repeated filling and emptying of an intermediate volume pressure infusion using positive displacement pumps A61M5/142
• CPC Class Codes: A61M 5/16854 : by monitoring line pressure
• CPC Class Codes: A61M 5/172 : electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61M 5/3146 : Priming, e.g. purging, reducing backlash or clearance
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection

Abstract

Embodiments of the present invention utilize a closed-loop feedback control system to ensure accurate drug delivery. This control system may, for example, utilize a flow sensor to measure the volume of delivery and an intelligent control algorithm to anticipate and compensate for overdoses and underdoses. Feedback control systems in accordance herewith can be applied to any piston- or plunger-driven pump system utilizing sensors that measure flow directly or indirectly. In some embodiments, adjustments are made based on the flow “tail” that occurs in a piston- or plunger-type pump as relaxation of the plunger material continues to push fluid out of the drug reservoir; this residual flow eventually ceases after the plunger returns to its natural state.

Claims

1. A drug pump device comprising:

a drug reservoir;

an exit member for fluidically connecting the reservoir with a drug injection site;

a sensor;

an electrolysis pump comprising a pump chamber in mechanical communication with the drug reservoir via an intervening displacement member, the electrolysis pump being operable to exert a pressure to drive the displacement member toward the exit member and thereby force therethrough fluid in the drug chamber; and

control circuitry for (i) storing a target delivered volume over a specified time, (ii) operating the electrolysis pump to force fluid from the drug reservoir into the exit member in pulses having a time window defined by a pump-start time when pumping begins and a pump-stop time when the pump is shut off, the time window corresponding to the target delivered volume at a predetermined flow rate, (iii) based on signals received from the sensor, measuring a volume of fluid through the exit member resulting from a pulse, the measured volume including a pulse volume through the exit member during the pulse and an additional tail volume through the exit member after the pulse, and (iv) adjusting the pulse time window based on the measured pulse volume and tail volume to conform collectively to the target delivered volume.

2. The device of claim 1, wherein the sensor is at least one pressure sensor.

3. The device of claim 1, wherein the sensor is at least one flow sensor.

4. The device of claim 1, wherein the sensor comprises at least one flow sensor and at least one pressure sensor.

5. The device of claim 1, wherein the target delivered volume corresponds to a single bolus, the control circuitry causing measuring to occur during a priming stage and causing adjustment to occur during a delivery stage.

6. The device of claim 1, wherein the control circuitry causes the target delivered volume to be dispensed through the exit member over a sequence of time-separated pulses occurring over a time interval, the control circuitry causing measuring to occur during a first time interval and causing adjustment to occur during a second time interval following the first time interval.

7. The device of claim 6, wherein the adjustment is based on the measured pulse volume and tail volume from a plurality of pulses.

8. In a drug pump device comprising a drug reservoir, an exit member for fluidically connecting the reservoir with a drug injection site, and an electrolysis pump operable to force fluid from the drug reservoir into the exit member in pulses each having a time window defined by a pump-start time when pumping begins and a pump-stop time when the pump is shut off, the time window corresponding to a target delivered volume at a predetermined flow rate, a method of controlling an actual delivery volume of fluid to conform to a target delivery volume, the method comprising:

measuring a volume of fluid through the exit member resulting from a pulse, the measured volume including (i) a pulse volume through the exit member during the pulse and (ii) an additional tail volume through the exit member after the pulse; and

adjusting the pulse time window based on the measured pulse volume and tail volume to conform collectively to the target delivered volume.

9. The method of claim 8, wherein the measurement is made with at least one pressure sensor.

10. The method of claim 8, wherein the sensor is at least one flow sensor.

11. The method of claim 8, wherein the target delivered volume corresponds to a single bolus, the measuring step occurring during a priming stage and the adjusting step occurring during a delivery stage.

12. The method of claim 8, wherein the target delivered volume is dispensed through the exit member over a sequence of time-separated pulses occurring over a time interval, the measuring step occurring during a first time interval and the adjusting step occurring during a second time interval following the first time interval.

13. The method of claim 12, wherein the adjusting step is based on the measured pulse volume and tail volume from a plurality of pulses.