IMPLANTABLE INDUSION PUMP

• US 3,731,681 A
• Filed: 01/14/1972
• Issued: 05/08/1973
• Est. Priority Date: 05/18/1970
• Status: Expired due to Term

• Current Assignee: Frank D. Dorman, Henry Buchwald, Perry J. Blackshear, Perry L. Blackshear Jr, Richard L. Varco
• Original Assignee: Frank D. Dorman, Henry Buchwald, Perry J. Blackshear, Perry L. Blackshear Jr, Richard L. Varco
• Inventors: Dorman, Frank D., Buchwald, Henry, Blackshear, Perry J., Blackshear, Perry L. Jr., Varco, Richard L.
• Primary Examiner(s): Medbery, Aldrich F.
• Application Number:
  US05/217,879
• Time in Patent Office: 480 Days
• Field of Search: 128/214R,214F,214.2,216,1R,260 222/386.5 3/1
• US Class Current: 604/141
• CPC Class Codes: A61M 5/141 with capillaries for restricting fluid flow
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16877 Adjusting flow; Devices for setting a flow rate

Abstract

An implantable pump for infusing drugs or other chemicals or solutions into the body at a uniform slow flow rate. The pump comprises a housing divided into two chambers separated by a bellows, diaphragm or other pressure-communicating interphase. A volatile liquid partially filling one chamber provides 9 constant pressure energy source to act upon the interphase to force liquid infusate from the other chamber through a capillary tube or other flow-regulating resistance element to the infusion site. The infusate chamber is closed as by means of a self puncture sealing refill stopper. The pump is implanted with the refill stopper disposed under the skin and the pump is refilled periodically by injection through the skin.

Claims

1. An infusion pump for implantation in a living body comprising:

A. a housing, B. means for dividing the housing into first and second fluidtight chambers, the dividing means being movable relative to the housing so as to vary the volumes of the chambers in a reciprocal manner, C. an inlet conduit located at a first position on the housing leading to the second chamber, D. at least one outlet conduit located at a second position on the housing adjacent to but spaced from said inlet conduit communicating with the second chamber and for leading to an infusion site in the body, E. means in the first chamber for moving the dividing means to reduce the volume of the second chamber so that a fluid in the second chamber may be forced through the outlet conduit, and F. a self-sealing, penetrable member in said inlet conduit, said member being unobstructed so that the pump can be implanted in the body with the unobstructed penetrable member situated adjacent a surface area of the body whereby the second chamber can be refilled with fluid periodically by injection through the skin.

2. being sealed with respect to the interior of the housing, and

3. being compressible in response to pressure exerted on the ouside of the end wall, C. an inlet conduit leading to the interior of the bellows from the outside of the housing, C. an outlet conduit communicating with the interior of the bellows for conducting fluid from the interior of the bellows to an infusion site in the body, and E. a self-sealing, penetrable member in the inlet conduit, said penetrable member being unobstructed so that the pump can be implanted in the body with the unobstructed member situated adjacent a surface area of the body whereby the bellows can be refilled with fluid periodically by injection through the skin.

4. The pump defined in claim 1 and further including fluid flow regulating means in the outlet conduit.

5. An infusion pump for implantation in a living body comprising:

A. a housing including an inlet means, B. a metal bellows within the housing, the bellows

6. The pump defined in claim 5 and further including a volatile liquid in the housing outside the bellows which exerts a sufficient vapor pressure at physiological temperatures to compress the bellows and force the bellows contents through the outlet conduit.

7. The pump defined in claim 5 and further including means for controlling the rate of flow of fluid through the outlet conduit.

8. The pump defined in claim 5 wherein the penetrable member is comprised of a penetrable self-sealing stopper.

9. The pump defined in claim 5 and further including means for limiting the extent to which the bellows can be compressed in response to the pressure exerted on its end wall.

10. An infusion pump for implantation in a living body comprising:

A. a housing, B. first and second chambers within the housing, C. a liquid-tight, vapor-tight, pressure-communicating metal bellows separating the chambers, said bellows having an open mouth at one end and closed wall at the other end, the mouth of the bellows being secured in liquid-tight, vapor-tight relation, the first chamber being provided with an inlet means and lying between the inside walls of the housing and the bellows and the second chamber lying within the bellows, D. an entry port into the second chamber and liquid-tight closure means therefor, the closure means being penetrable from the outside of a living body after implantation therein by injection through the skin, and E. at least one discharge port from the second chamber spaced from but adjacent to said entry port.

11. A pump according to claim 10 further characterized in that:

A. a recessed, cup-like member is disposed in one end of the housing extending within the mouth of the bellows, B. an aperture is provided in the cup-like member with a fitting therein having a channel in communication with the second chamber, and C. the bellows is collapsible into an annular space between the cup-like member and the housing wall.

12. The pump according to claim 10 and further characterized in that:

A. the penetrable closure means is an elastic member, and B. an annular retainer having a central aperture is secured to the external end of the fitting in engagement with the elastic member.

13. The pump according to claim 12 and further characterized in that:

A. the housing and the fitting having contours conforming generally to the contours of the implantation site in the body, and B. a conduit is connected to the discharge port for conducting infusate from the bellows to an infusion site in the body.

14. The pump according to claim 13 wherein the conduit is a length of capillary tubing.

15. The pump according to claim 10 and further characterized in that the first chamber is partially filled with a stable, volatile liquid that exerts a vapor pressure of greater than 1 atmosphere at physiological temperatures, whereby the pump is self-powered through body warmth.

16. The method of infusing liquids into a living boby, said method comprising:

A. implanting a self-powered pump according to claim 15 in a living body, with the closure means to the entry port of the second chamber of the pump underlyIng and facing the skin, B. connecting the discharge port to at least one infusion site in the body, C. injecting infusate through the skin of the body and through the closure means to fill the second chamber thereby condensing the vapor within the first chamber to charge the power source, and D. expanding the vapor in the first chamber through body warmth to gradually collapse the second chamber to expel the infusate in the second chamber through the discharge port to the infusion site.

17. The method of infusing fluids into a living body, said method comprising the steps of:

A. charging the power cell of a vapor pressure pump with a stable, volatile liquid that exerts an appreciable vapor pressure at physiological temperatures, B. forming a self-sealing, penetrable member in the discharge port of the pump, C. implanting the pump in the body so that the penetrable member underlies the skin, D. expanding the pressure-exerting vapor in the power cell through body warmth to pump infusate through the discharge port to an infusion site in the body, and E. injecting additional fluid through the skin and through the penetrable member periodically to refill the pump with infusate and, at the same time, condense the pressure-exerting vapor so as to recharge the power cell.