LIQUID INFUSION APPARATUS

• US 3,559,644 A
• Filed: 12/14/1967
• Issued: 02/02/1971
• Est. Priority Date: 12/14/1967
• Status: Expired due to Term

• Current Assignee: Abbott Laboratories
• Original Assignee: Paul E. Stoft, Robert F. Shaw
• Inventors: Stoft, Paul E., Shaw, Robert F.
• Application Number:
  US04/690,440
• Time in Patent Office: 1,146 Days
• US Class Current: 604/123
• CPC Class Codes: A61M 5/14216 Reciprocating piston type

Abstract

Liquid infusion apparatus provides reliable administration of liquids and blood transfusions into the body (intravenous, intraarterial or subcutaneous) at a preset and regulated rate in a convenient, inexpensive and completely safe manner. The apparatus includes liquid pumping an valving mechanisms and gas relief means which prevent both the back flow of liquid into the liquid reservoir and the injection of air into the blood stream of the patient.

Claims

2. Liquid infusion apparatus for use with source means containing a liquid to be administered to a patient, the apparatus comprising:

a chamber for confining a volume of fluid and including converging walls forming an internal region of decreasing cross-sectional area with length of the chamber for focusing a pressure wave at an outlet disposed near the end of said chamber of smallest cross-sectional area;

outlet valve means disposed at said outlet and coupled to said chamber for providing outlet flow of liquid therethrough only for values of pressure exerted thereon above a selected value;

fluid inlet means connected for receiving liquid from the source means and coupled to said chamber for supplying fluid therethrough to said chamber;

transducer means disposed with respect to said chamber near the end thereof of largest cross-sectional area for increasing the fluid pressure in the internal region of said chamber to a value above said selected value for producing outFlow of liquid through said outlet valve means in response to an electrical signal applied to said transducer means;

gas relief means including an aperture of selected cross section disposed at the fluid inlet in a wall of said chamber near the end thereof of largest cross-sectional area; and

conduit means coupled to said outlet valve means for supplying the outlet flow of liquid to a patient.

3. Liquid infusion apparatus as in claim 2 wherein:

said transducer means is a piezoelectric element arranged on a wall of said chamber disposed near the end thereof of largest cross section to displace a portion of said wall in response to electrical signal applied to said element for producing a pressure increase in the infusion liquid within said chamber near the end thereof of smallest cross section in excess of said selected value.

4. Liquid infusion apparatus as in claim 3 wherein:

said chamber is conically shaped;

said transducer means includes a toroidally shaped piezoelectric element disposed on the upper wall of said chamber remote from said outlet valve for producing a pressure wave in infusion liquid within said chamber in response to electrical signal applied to said piezoelectric element, whereby the pressure wave is confined and focused by the conically shaped chamber to exert liquid pressure on said outlet valve in excess of said selected value; and

said aperture is disposed in said upper wall of said chamber within the inner area of said toroidally shaped piezoelectric element.