Medical pump

• US 20040267201A1
• Filed: 06/19/2003
• Published: 12/30/2004
• Est. Priority Date: 06/18/2003
• Status: Active Grant

• Current Assignee: Q-Med Aktiebolag (Nestle SA)
• Original Assignee: Q-Med Aktiebolag (Nestle SA)
• Inventors: Agerup, Bengt
• Granted Patent: US 7,278,985 B2
• Time in Patent Office: Days
• US Class Current: 604/152
• CPC Class Codes: A61M 2005/3115 spring-assisted
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/1452 pressurised by means of pistons
• CPC Class Codes: A61M 5/19 having more than one chamber , e.g. including a manifold coupling two parallelly aligned syringes through separate channels to a common discharge assembly surgical glue applicators A61B17/00491
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling
• CPC Class Codes: A61M 5/31525 Dosing burettes, pipettes B01L3/02
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button

Abstract

A medical pump, comprising a reservoir having a fluid enclosing portion and a tubular element, the inside of which is arrangeable in fluid communication with the fluid enclosing portion for allowing fluid to pass into the tubular element. The fluid enclosing portion contains a volume of fluid sealed from communication with air and the fluid enclosing portion is adapted to reduce in volume essentially to the same extent as any volume of fluid transferred into the inside of the tubular element. The invention also relates to a method of delivering a medical fluid.

Claims

1. A medical pump, comprising

a reservoir having a fluid enclosing portion;

a tubular element, the inside of which is arrangeable in fluid communication with the fluid enclosing portion for allowing fluid to pass into the tubular element;

an inner seal movable inside the tubular element between an advanced and a retracted position, wherein the inner seal is retractable from the advanced position to enable the fluid to be transferred from the fluid enclosing portion into an internal space defined by the tubular element and the retracted inner seal, and wherein the inner seal is advanceable from the retracted position for delivering out of the pump fluid present in said internal space;

wherein said fluid enclosing portion contains a volume of fluid sealed from communication with air and the fluid enclosing portion is adapted to reduce in volume essentially to the same extent as any volume of fluid transferred into said internal space of the tubular element.

2. The medical pump as claimed in claim 1, wherein said fluid enclosing portion comprises a outer seal which is movable inside the reservoir and which defines a delimitation of the fluid contained in the fluid enclosing portion, the outer seal being arranged to move relative to the tubular element when the inner seal is retracted from said advanced position.

3. The medical pump as claimed in claim 2, wherein the tubular element is located inside the reservoir, wherein the outer seal extends from an inner surface of the reservoir to an outer surface of the tubular element.

4. The medical pump as claimed in claim 3, wherein the tubular element is movable between an advanced administering position and a retracted filling position, wherein the outer seal is adapted to move relative to the tubular element when the tubular element is retracted from said administering position.

5. The medical pump as claimed in claim 4, wherein mutually contacting surfaces of the inner seal and the tubular element provide a first frictional force F₁, wherein the tubular element is adapted to be retracted from the administering position by application of a retracting force on the inner seal.

6. The medical pump as claimed in claim 5, wherein the tubular element is adapted to be advanced from the filling position by application of an advancing force on the inner seal.

7. The medical pump as claimed in claim 4, wherein mutually contacting surfaces of the tubular element and the outer seal provide a second frictional force F₂ against advancing movement of the tubular element towards its administering position, and wherein mutually contacting surfaces of the outer seal and the reservoir provide a third frictional force F₃ which is smaller than said second frictional force F₂, wherein the outer seal is advanced together with the tubular element during advancement of the tubular element towards its administering position.

8. The medical pump as claimed in claim 4, wherein mutually contacting surfaces of the outer seal and the reservoir provide a third frictional force F₃, and wherein mutually contacting surfaces of the tubular element and the outer seal provide a fourth frictional force F₄ against retracting movement of the tubular element towards its filling position, said third frictional force F₃ being larger than said fourth frictional force F₄.

9. The medical pump as claimed in claim 4, wherein

mutually contacting surfaces of the inner seal and the tubular element provide a first frictional force F₁;

mutually contacting surfaces of the tubular element and the outer seal provide a second frictional force F₂ against advancing movement of the tubular element towards its administering position;

mutually contacting surfaces of the outer seal and the reservoir provide a third frictional force F₃; and

mutually contacting surfaces of the tubular element and the outer seal provide a fourth frictional force F₄ against retracting movement of the tubular element towards its filling position,

wherein said frictional forces satisfy the relationship F₁>

F₂>

F₃>

F₄.

10. The medical pump as claimed in claim 4, wherein the reservoir comprises an abutment surface provided with an outlet region for fluid delivery out of the pump, wherein, in said administering position, an end portion of the tubular element abuts said abutment surface in such manner that said internal space of the tubular element is in communication with said outlet region.

11. The medical pump as claimed in claim 10, wherein the abutment surface is a sealing surface preventing fluid from flowing between the interior of the tubular element and the reservoir when the tubular element is in said administering position.

12. The medical pump as claimed in claim 11, wherein said sealing surface is configured as a non-return valve which allows fluid to flow out from the pump through said outlet region but which prevents fluid to enter the pump through said outlet region.

13. The medical pump as claimed in claim 12, wherein the retracted filling position of the tubular element is determined by an end member of the reservoir preventing further retraction of the tubular element.

14. The medical pump as claimed in claim 4, wherein said inner seal is connected to an elongate actuator movable inside the tubular element, the actuator being controllable from the outside of the reservoir,

wherein, when the inner seal is retracted from the advanced position due to a retracting force acting on the actuator, the tubular element is retracted to its filling position due to friction against the inner seal, and

wherein the inner seal is adapted to overcome the friction and move relative to the tubular element when the tubular element is at its filling position and the actuator is subjected to a retraction force.

15. The medical pump as claimed in claim 14, wherein a spring is provided and biased to exert a force on the elongate actuator in the longitudinal direction of the actuator.

16. The medical pump as claimed in claim 1, wherein the pump is provided as a package in which the reservoir is pre-filled with a medical fluid in the form of a gel having a viscosity above 1000 mPa*s, preferably above 10 000 mPa*S, in particular between than 100 000 mPa*s and 1 000 000 mPa*s.

17. A medical pump, comprising

a reservoir containing a fluid enclosing portion;

a tubular element, the inside of which is arrangeable in fluid communication with the fluid enclosing portion for allowing fluid to pass into the tubular element, the tubular element having an advanced fluid administering position;

an inner seal movable inside the tubular element between an advanced and a retracted position, wherein the inner seal is retractable from the advanced position for enabling fluid to be transferred from the fluid enclosing portion into an internal space defined by the tubular element and the retracted inner seal, and wherein the inner seal is advanceable from the retracted position for delivering out of the pump fluid present in said internal space;

wherein the reservoir is provided with a movable outer seal disposed between an outside surface of the tubular element and an inside surface of the reservoir, the outer seal preventing air from mixing with fluid contained in the fluid enclosing portion and being arranged to move relative to the tubular element when the tubular element is retracted from said administering position.

18. A method of delivering a medical fluid, comprising:

providing a medical pump comprising a reservoir having a fluid enclosing portion and a tubular element, the inside of which is arrangeble in fluid communication with the fluid enclosing portion;

reducing the volume of the fluid enclosing portion by transferring a portion of said fluid from the fluid enclosing portion into an internal space of the tubular element, wherein the volume of the fluid enclosing portion is reduced with essentially the same volume as the volume of fluid transferred into the internal space of the tubular element; and

delivering out from the pump the transferred fluid contained in the internal space of the tubular element.

19. The method according to claim 18, wherein the act of providing a pump comprises providing the fluid enclosing portion with an outer seal which is movable inside the reservoir and which defines a delimitation of the fluid contained in the fluid enclosing portion to prevent te fluid from mixing with air, wherein the act of reducing the volume comprises moving the outer seal relative to the tubular element by transferring a portion of said fluid from the fluid enclosing portion into an internal space of the tubular element.

20. The method according to claim 18 further comprising:

repeating the preceding steps for further delivering of fluid from the pump.

21. The method according to claim 19 further comprising:

moving the outer seal relatively to the tubular element by moving the tubular element from an advanced administering position towards a retracted filling position.

22. The method according to claim 21 further comprising:

retaining the position of the outer seal relatively to the reservoir when the tubular element is moved from the advanced administering position towards the retracted filling position.

23. The method according to claim 22, further comprising:

advancing the outer seal together with the retracted tubular element by moving the retracted tubular element towards the advanced administering position.

24. The method according to claim 19, wherein the act of moving the outer seal comprises establishing a negative pressure inside the tubular element, which negative pressure forces the fluid and the outer seal to be moved.

25. The method according to claim 24, wherein the act of providing a pump comprises providing a movable inner seal inside the tubular element, wherein the act of establishing the negative pressure comprises moving said inner seal inside the tubular element from an advanced position to a retracted position, thereby transferring a portion of said fluid from the reservoir into the internal space of the tubular element.

26. A method according to claim 25, wherein the act of delivering fluid out from the pump comprises moving said inner seal from the retracted position to the advanced position, thereby delivering out from the pump the transferred fluid contained in the internal space of the tubular element.