Compensating drug delivery system

• US 20030018304A1
• Filed: 05/29/2001
• Published: 01/23/2003
• Est. Priority Date: 05/29/2001
• Status: Active Grant

• Current Assignee: TheraFuse, Inc.
• Original Assignee: TheraFuse, Inc.
• Inventors: Sage, Burton H. Jr.
• Granted Patent: US 6,582,393 B2
• Time in Patent Office: Days
• US Class Current: 604/246
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/0061 Methods for using microneedles
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: A61M 5/148 flexible, e.g. independent bagsA61M5/155 takes precedence
• CPC Class Codes: A61M 5/152 pressurised by contraction of elastic reservoirs containers for dispensing contents by contraction of an elastic bag provided therein, in general B65D83/0061
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/16881 Regulating valves on-off valves, e.g. clamps A61M39/28

Abstract

A compensating drug delivery system for delivery of medicaments to animals is described. A drug-containing reservoir is connected to a needle array through a flow tube. Medicament delivery to the animal through this flow tube is regulated by the combined action of a metering means and a valving means, and inaccuracies in delivery rate are compensated. The metering means and the valving means are microprocessor controlled to insure that the medication administered is according to a pre-established protocol.

Claims

1. A device for delivering a liquid medicament to an animal comprising

a) a reservoir containing said liquid medicament under mechanical pressure, and

b) skin penetration means for penetrating the skin of an animal and for conducting said liquid medicament into said animal, and

c) a flow tube connecting said reservoir to said skin penetration means to conduct said liquid medicament to said skin penetration means, and

d) valving means to start or stop flow of said liquid medicament along said flow tube, and

e) metering means to measure properties of flow of said liquid medicament along said flow tube, and

f) memory means with a schedule for delivery of said liquid medicament stored therein, and

g) memory means with an algorithm stored therein for calculating the timing of actuation of said valving means to administer said liquid medicament according to said schedule, and

h) memory means with a second algorithm stored therein for adjusting the timing of actuation of said valving means using said properties of flow of said liquid medicament to compensate for variations in flow rate parameters, and

i) a calculation means to execute said algorithms, and

j) a power source to power said memory means, said calculation means, said valving means, and said metering means.

2. The device of claim 1 comprising two components;

a first disposable component comprising said medicament containing reservoir, said flow tube, and said skin penetration means, and a second reusable component comprising said valving means, said metering means, said memory means, said calculation means, and said power source.

3. The device of claims 1 or 2 wherein said mechanical pressure is between 0.1 and 100 pounds per square inch.

4. The device of claim 3 wherein the liquid medicament is an insulin.

5. The device of claim 3 wherein the liquid medicament is a narcotic analgesic.

6. The device of claim 5 wherein the narcotic analgesic is morphine, oxymorphone or fentanyl.

7. The device of claim 3 wherein said skin-penetrating means is at least one needle.

8. The device of claim 7 wherein said needles have an outside diameter of less than 0.2 mm.

9. The device of claim 7 wherein said needles are made using a shape memory alloy

10. The device of claim 3 wherein said flow tube is made of a flexible material

11. The device of claim 3 wherein said metering means measures the time interval required for an increment of said liquid medicament to flow a prescribed distance along said flow tube.

12. The device of claim 11 wherein said second algorithm uses said time interval to compensate for pressure variations in said reservoir.

13. The device of claim 11 wherein said second algorithm uses said time interval to compensate for variations of viscosity of said liquid medicament.

14. The device of claim 11 wherein said second algorithm uses said time interval to compensate for variations in the inside diameter of said flow tube.

15. The device of claim 2 wherein said disposable component includes a surface with an adhesive for adhering said disposable component to the skin of an animal.

16. The device of claim 3 wherein the volume of said liquid medicament to be delivered is between one microliter and one liter.

17. The device of claim 3 wherein said metering means measures the volumetric flow rate of said liquid medicament.

18. The device of claim 18 wherein said second algorithm uses said volumetric flow rate to compensate for actual medicament pressure, medicament viscosity, and/or flow tube inside diameter.

19. The device of claim 18 wherein said metering means uses a voltage generated by the flow of ions in said medicament through a magnetic field to measure said volumetric flow rate.

20. The device of claim 20 wherein said second algorithm use said voltage to compensate for actual medicament pressure, medicament viscosity, and/or flow tube inside diameter.

21. A method of providing accurate and reproducible delivery of a liquid medicament to an animal including the steps of

a) creating a medicament flow path into said animal from a pressurized medicament reservoir through a replaceable flow tube,

b) providing valving means to stop or start medicament flow through said replaceable flow tube,

c) establishing nominal values for 1) the volume of medicament between two points of said replaceable flow tube, and 2) the time required for an increment of medicament to flow between said two points of said replaceable flow tube,

d) measuring the actual time required for said liquid medicament to flow between said two points of said replaceable flow tube

e) establishing a time schedule of desired delivery of said liquid medicament to said animal

f) using said desired delivery, said actual time, said nominal time, and said nominal volume to calculate the time required to keep open said valving means to provide said desired delivery of said liquid medicament according to said time schedule.