Implantable infusion pump

• US 5,382,236 A
• Filed: 06/14/1993
• Issued: 01/17/1995
• Est. Priority Date: 11/29/1990
• Status: Expired due to Fees

• Current Assignee: Tricumed Medizintechnik GmbH
• Original Assignee: Anschutz & Company GmbH
• Inventors: Pfister, Gerd, Otto, Karl-Heinz
• Primary Examiner(s): Hirsch, Paul J.
• Application Number:
  US07/934,520
• Time in Patent Office: 582 Days
• Field of Search: 604/141, 604/891.1, 604/890.1
• US Class Current: 604/141
• CPC Class Codes: A61M 5/14276 specially adapted for implantation

Abstract

An infusion pump with a flexible medication container, a chamber containing a C₂ Cl₂ F₄ propellant gas acting upon the medication container and a capillary tube acting as a choke. The propellant gas chamber accommodates a pressure of 2.5 bar over atmospheric.

Claims

1. In an infusion pump for implanting within the body of a patient, the pump including an outer housing enclosing a propellant chamber and an elongated inner housing containing a medication, the propellant chamber containing at least 2.5 bar over atmospheric pressure of a propellant gas, a capillary tube of restricted diameter leading out of the inner housing for restricting the medication flow and a means for filling the inner housing with the medication, the improvement comprising the housing containing the medication is elastic, and the propellant is dichlorotetrafluoroethane to cause a minimal flow rate change for the medication to be infused when pressure or temperature in the patient changes.

2. The infusion pump according to claim 1 wherein the elastic elongated inner housing is a metal membrane corrugated bellows.

3. The infusion pump according to claim 2 wherein the metal membrane is made from titanium.

4. The infusion pump according to claim 1 wherein the outer housing is made from titanium.