Piston-pumping system having o-ring seal properties

• US 7,284,474 B2
• Filed: 12/03/2003
• Issued: 10/23/2007
• Est. Priority Date: 12/06/2002
• Status: Active Grant

• Current Assignee: Boehringer Ingelheim International GmbH (C.H. Boehringer Sohn AG & Co. KG)
• Original Assignee: Boehringer Ingelheim International GmbH (C.H. Boehringer Sohn AG & Co. KG)
• Inventors: Geser, Johannes, Eigemann, Jutta
• Primary Examiner(s): Sirmons; Kevin C.
• Assistant Examiner(s): Schell; Laura C.
• Application Number:
  US10/727,286
• Publication Number:
  US 20040134495A1
• Time in Patent Office: 1,420 Days
• Field of Search: 604/131, 604/134, 604/135, 604/151, 604/152, 277/438, 277/910, 921/68, 417/416
• US Class Current: 92/168
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• 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 37/0015 by using microneedles
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14248 of the skin patch type
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: F04B 19/006 Micropumps F04B43/043 and F04B43/095 take precedence
• CPC Class Codes: F04B 53/14 Pistons, piston-rods or piston-rod connections
• CPC Class Codes: F04B 53/164 Stoffing boxes
• CPC Class Codes: F16J 15/32 with elastic sealings, e.g. O-rings

Abstract

The present invention relates to a piston pumping system for substantially gas-free measurement and/or pumping of predetermined quantities of liquids, preferably pharmaceutical liquids containing oxidation-prone ingredients. Preferably, the system is used as a micropump or as a component thereof in medical devices such as transdermal therapeutic systems, for example.

Claims

1. A piston pumping system comprising a piston guided within a guide tube and capable of performing a stroke movement along its longitudinal axis, opening into a pumping chamber, the pumping chamber being connected via a liquid-conveying connection with valve to a storage vessel and from the pumping chamber a liquid conveying connection leads to a device for delivering the liquid, wherein within the guide tube is formed an O-ring seal held by a groove which seals off the piston, has a gas permeation coefficient of 100 to 500 N*cm³*mm/(m²*h*bar) for nitrogen (N₂) and a radial compression of less than 30% and the seal fills the groove with a groove filling level of more than 90%.

2. A piston pumping system according to claim 1, wherein the groove filling level is more than 95%.

3. A piston pumping system according to claim 1, wherein the valve is a non-return valve.

4. A piston pumping system according to claim 1, wherein a non-return valve is formed in the connection to a device for delivering the liquid.

5. A piston pumping system according to claim 1, wherein the piston has a diameter of 0.25 to 4 mm.

6. A piston pumping system according to claim 1, wherein the piston has a length of 5 mm to 10 cm.

7. A piston pumping system according to claim 1, wherein the stroke movement of the piston along its longitudinal axis covers a length from 1 mm to 5 cm.

8. A piston pumping system according to claim 1, wherein the O-ring seal consists of silicon.

9. A piston pumping system according to claim 1, wherein the piston is a hollow piston in which the liquid-conveying connection with a valve, which connects the pumping chamber to a storage vessel, is integrated.

10. A piston pumping system according to claim 1, wherein the movement of the piston is mechanically controlled.

11. A piston pumping system according to claim 10, wherein the piston is moved by a helical spring.

12. A piston pumping system according to claim 1, wherein the movement of the piston is electronically controlled.

13. A piston pumping system according to claim 12, wherein the piston is controlled by a microchip.

14. A piston pumping system according to claim 12, wherein the piston is moved by a piezoelectric element.

15. A piston pumping system according to claim 1, wherein the pump volume is from 1 microliter to 1 ml.

16. A piston pumping system according to claim 1, wherein the device for delivering the liquid is at least one nozzle, at least one micro-pin or at least one microcutter along which the liquid is guided, at least one canula and/or at least one outlet.

17. A piston pumping system according to claim 1, wherein the cord thickness of the O-ring is from 0.3 to 3 mm.