Negative pressure pump

• US 6,283,943 B1
• Filed: 02/19/1999
• Issued: 09/04/2001
• Est. Priority Date: 02/19/1999
• Status: Expired due to Term

• Current Assignee: Minimed, Inc. (Medtronic Plc)
• Original Assignee: Minimed, Inc. (Medtronic Plc)
• Inventors: Dy, Norman, Van Antwerp, William P.
• Primary Examiner(s): Nguyen, Anhtuan T.
• Assistant Examiner(s): Thompson, Michael M.
• Application Number:
  US09/253,383
• Time in Patent Office: 928 Days
• Field of Search: 604/891.1, 604/890.1, 604/93, 604/132, 604/140, 604/141, 604/142, 604/502, 604/505, 128/DIG.12
• US Class Current: 604/141
• CPC Class Codes: A61M 2209/045 for filling, e.g. for filling reservoirs
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14276 specially adapted for implantation

Abstract

A medication infusion pump includes a housing, a medication chamber defined within the housing, means for supplying the medication from the medication chamber to a patient, a reservoir defined within the housing and adapted to apply a predetermined negative pressure to a medication within the medication chamber, and a gas within the reservoir. The gas has a vapor pressure less than ambient atmospheric pressure at normal human physiological temperature, more specifically less than 14.7 psia at 37° C.

Claims

1. A method of inhibiting undesirable leakage from a medication infusion pump comprising employing a non-ozone depleting gas having a vapor pressure less than ambient atmospheric pressure at 37°

C. within the medication infusion pump, wherein the medication infusion pump comprises;

a) a housing,

b) a medication chamber defined within the housing,

c) means for supplying the medication from the medication chamber to a patient,

d) a reservoir defined within the housing and adapted to apply a predetermined negative pressure to the medication chamber; and

e) the non-ozone depleting gas within the reservoir, wherein the gas has a vapor pressure less than ambient atmospheric pressure at normal human physiological temperature;

wherein the vapor pressure of the gas applies a negative pressure to the medication chamber so that undesirable leakage is inhibited and wherein the method of inhibiting undesirable leakage from a medication infusion pump comprising employing a non-ozone depleting gas in said medication infusion pump further functions to avoid depletion of the ozone layer.

2. The method of claim 1 wherein the gas is non toxic.

3. The method of claim 1 wherein the gas has a vapor pressure less than 14.7 psia at 37°

C.

4. The method of claim 3 wherein the gas has a vapor pressure less than 10.7 psia at 37°

C.

5. The method of claim 1 wherein the gas is selected from the group consisting of cyclopentane, 2,2-dimethylbutane, 1,3-pentadiene and 2-methyl-2-butene.

6. The method of claim 5 wherein the gas is selected from the group consisting of cyclopentane and dimethylbutane.

7. The medication infusion pump of claim 1 comprising a plurality of gases within the reservoir, wherein the plurality of gases has a combined vapor pressure less than 14.7 psia at 37°

C.

8. The method of claim 1 wherein the medication chamber and the reservoir are separated by a barrier which is resistant to the gas.

9. A method of facilitating the introduction of a medication into a medication chamber within a medication infusion pump comprising employing a non-ozone depleting gas having a vapor pressure less than ambient atmospheric pressure at 37°

C. within the medication infusion pump, wherein the medication infusion pump comprises;

a) a housing,

b) a medication chamber defined within the housing,

c) means for supplying the medication from the medication chamber to a patient,

d) a reservoir defined within the housing and adapted to apply a predetermined negative pressure to the medication chamber; and

e) the non-ozone depleting gas within the reservoir, wherein the gas has a vapor pressure less than ambient atmospheric pressure at normal human physiological temperature;

wherein the vapor pressure of the gas applies a negative pressure to the medication chamber that facilitates the flow of the medication from a supply source into the medication chamber and wherein the method of facilitating the introduction of a medication into a medication chamber within a medication infusion pump comprising employing a non-ozone depleting gas in said medication infusion pump further functions to avoid depletion of the ozone layer.

11. The method of claim 9, wherein the gas has a vapor pressure less than 14.7 psia at 37°

C.

12. The method of claim 9 wherein the gas has a vapor pressure less than 10.7 psia at 37°

C.

13. The method of claim 9 wherein the gas is selected from the group consisting of cyclopentane, 2,2-dimethylbutane, 1,3-pentadiene and 2-methyl-2-butene.

14. The method of claim 13 wherein the gas is selected from the group consisting of cyclopentane and dimethylbutane.

15. The medication infusion pump of claim 9 comprising a plurality of gases within the reservoir, wherein the plurality of gases has a combined vapor pressure less than 14.7 psia at 37°

C.

16. The method of claim 9 wherein the medication chamber and the reservoir are separated by a barrier which is resistant to the gas.

10. The method of 9 wherein the gas is non toxic.

17. A method of avoiding depletion of the ozone layer comprising using a non-ozone depleting gas having a vapor pressure less than ambient atmospheric pressure at 37°

C. to inhibit a substance from escaping from the interior of a medication infusion pump to the exterior environment, wherein the medication infusion pump comprises;

a) a housing,

b) a medication chamber defined within the housing,

c) means for supplying the medication from the medication chamber to a patient,

d) a reservoir defined within the housing and adapted to apply a predetermined negative pressure to the medication chamber; and

e) the non-ozone depleting gas within the reservoir, wherein the gas has a vapor pressure less than ambient atmospheric pressure at normal human physiological temperature; and

wherein the vapor pressure of the gas applies a negative pressure to the medication chamber that inhibits a substance from escaping from the interior of a medication infusion pump to the exterior environment.

18. A method of avoiding depletion of the ozone layer comprising using a non-ozone depleting gas having a vapor pressure less than ambient atmospheric pressure at 37°

C. to facilitate the introduction of a medication into a medication chamber within a medication infusion pump, wherein the medication infusion pump comprises;

a) a housing,

b) the medication chamber defined within the housing,

c) means for supplying the medication from the medication chamber to a patient,

d) a reservoir defined within the housing and adapted to apply a predetermined negative pressure to the medication chamber, and

e) the non-ozone depleting gas within the reservoir, wherein the gas has a vapor pressure less than ambient atmospheric pressure at normal human physiological temperature; and

wherein the vapor pressure of the gas applies a negative pressure to the medication chamber that facilitates the flow of the medication from a supply source into the medication chamber.