Constant flush device

• US 4,300,571 A
• Filed: 07/27/1979
• Issued: 11/17/1981
• Est. Priority Date: 07/27/1979
• Status: Expired due to Term

• Current Assignee: Medex Incorporated (Smiths Group International Holdings Ltd.)
• Original Assignee: Medex Incorporated (Smiths Group International Holdings Ltd.)
• Inventors: Waldbillig, Charles C.
• Primary Examiner(s): HOWELL, KYLE
• Application Number:
  US06/061,305
• Time in Patent Office: 844 Days
• Field of Search: 128/673-675, 128/214 R, 128/274, 128/214 F, 128/214 E, 251/4, 251/7, 251/117, 251/334, 251/342
• US Class Current: 600/486
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61M 39/225 Flush valves, i.e. bypass valves for flushing line

Abstract

A blood pressure monitoring system in which an intravascular catheter is connected through flexible tubing to a transducer. The tubing between the catheter and the transducer is filled with physiological solution supplied from a bag under pressure of approximately 300 mm. of mercury. The supply line from the bag to the tube is in series with a capillary so that after the system is filled with the physiological solution, the capillary passes fluid from the supply to the catheter at the rate of around two to seven cc. per hour. Provision is made for bypassing the capillary for the purpose of fast flushing the system as would occur when the system is initially filled with fluid. The fast flush line consists of a plug in series with the line from the supply, the plug having upstream and downstream longitudinal grooves separated by a central collar. A flexible tube surrounds the plug and blocks passage from the upstream and downstream groove past the collar. The tube has a pull tab overlying the position of the grooves. Fast flushing is accomplished by pulling on the tab so that the fluid in the upstream groove can flow over the collar into the downstream groove.

Claims

1. In a constant flush system, including a catheter, a transducer, a main tube connected between said catheter and said transducer, and a fluid supply, a flow control connecting said fluid supply to said main tube, comprising,

means forming a capillary flow path from said fluid supply to said main tube,

a bypass flush valve from said fluid supply to said main tube comprising,

a plug having a central annular collar,

longitudinal grooves in said plug from each of its ends to said collar,

a resilient sleeve normally surrounding said collar in fluid-tight relation,

means connecting said sleeve between said supply and said main tube,

the end portions of said plug being of a reduced diameter,

fittings connected to said fluid supply and said main tube, said fittings receiving said reduced plug ends and abutting said collar,

said grooves having radial passages between said collar and said fittings to provide passageways to the external surface of the said collar while permitting minimal exposure of said sleeve to a column of fluid.

2. A constant flush assembly as in claim 1 in which the outside diameter of said collar and said fittings are of substantially the same dimension,

said collar and fittings being in abutting relation so as to eliminate annular grooves in said system which might entrap bubbles.