FLUSH VALVE

Abstract: A continuous flushing catheter includes a valve com­ prising a relatively rigid central portion (24) and a flexible outer portion (19) surrounding said central portion (24). The valve has a sealing surface (26) which engages the central portion (24) around its whole circumference in liquid sealing relationship. A pair of integral lever arms transmit a shape-deforming force to the flexible outer por­ tion (19) to lift a portion of the sealing surface (26) out of contact with the rigid cylinder (24), to permit passage of liquid through said valve.

Description: FLUSH VALVE BACKGROUND OF THE INVENTION The present invention -is specifically directed to an improved valve for permitting the rapid flushing of an intravascular catheter used in a system for monitoring conditions in the thoracic cavity during surgery, in an intensive care ward, in cardio vascular diagnostic laboratories etc. There have recently come on the market several devices for the continuous flushing of intravascular catheters wherein a glass capillary tube, such as a marine bore, is provided to limit the flushing to a very small amount. At the time of intstalling the catheter it is necessary to have a fast flush in order to completely fill the catheter with the flushing solution to prevent the danger of introducing an air bubble into the body of the patient whose condition is being monitored. One such catheter is made and sold by Sorenson Labs and is made in accordance with the teachings of U.S. patent 3,675,891. The present invention is an improvement over the device of the type described in the above mentioned Sorenson patent. While the valve of the present invention has other uses than in continuous flushing of catheter systems its construction and operation will be initially described in connection with such a system. THE PRIOR ART In addition to the above mentioned Sorenson patent 3,675,891 the art includes other valve devices such as those shown in U.S. patent to Cantor 2,706,101 and 2,946,555, to Harris 3,985,140, to alsace 3,901,246 and 4,018,231. However none of these patents show the integral molded pair of lever arms character izirg the present invention. BRIEr DESCRIPTION OF THE DRAWINGS F#ig. 1 is a diagramatic sectional view of the valve of the present invention. Fig. 2 is a diagramatic sectional vtied along the line 2-2 of Fig. 1 with the valve in the closed position and Fig. 3 is a sectional view similar to Fig. 2 taken on line 3-3 of Fig. 1 with the valve in the flush position: Referring to Figs. 1 and 2 the valve body 10 has three tubes 12, 14 and 16 connected thereto. Tube 12 is designed to be connected to the catheter, tube 14 is adapted to be connected to a pressure monitoring device and tube 16 is arranged to be connected to a sressurized source of flushing solution. The valve body 10 contains two tubular portions 19 and 21 containinc passages 20 and 22 respectively. In passage 20 there is provided a glass marine bore" capillary 24 having a cylindrical outer circumference. A flushing solution is prevented from by-passing the marine bore capillary 24 by cylindrical sealing ridges 26 formed in the interior portion of the body 10 defining the cavity 20. The body 10 is preferably formed of a pliable plastic or elastomer such as urethane having a Shore Adurameter of approximately 80. This body 10 is preferably formed of two pieces the major portion of which includes end piece 28 having two nipples which are integrally molded into the two tubes 14 and 16 respectively. A second end piece 30 having a single nipple is integrally molded into the tube 12. The marine bore cylinder 24 is held in position centrally of the cavity 20 by means of shoulders 32 on end piece 28 which cooperate with shoulders 34 on cap 30. These shoulders 32 and 34 do not extend around the circumference of the cavity 20 so they do not interfere with flow of the flushing fluid. In assembling the device, marine bore tube 24 is inserted into the cavity 20 until it is held in position by the shoulders 32. The cap 30 is then inserted and sealed by use of an appropriate adhesive with the shoulders 4 engaging the other end of the marine bore capillary. As will be noted the two sealing lips 26 tightly engage the complete circumference of the marine bore capillary to make a tight seal therel ith. When the device is fully assembled and pressurized liquid is fed from tube 16 into cavity 20 and passes through the marine bore capillary 24 at a 3 very low rate of flow, on the order of a few cm per hour. Referring now to Figs. 2 and 3 there is shown a cross-sectional view of Fig. 1. In Fig. 2 the valve is in normal closed position with the sealing lips 26 in sealing engagement with the outside of the capillary tube 24. This figure also shows the interval. lever arm 36 which is molded as a portion of the body 10 as can be seen in Fig. 2 the tubular portion 21 and the arm 36 form an integral pair of lever arms which are molded as an integral part of said body. These arms extend radially from tubular body 19. In Fig. 3 the lever arm 36 is shown as being moved towards the second lever arm (tube 21) so as to distort the body 19 of the valve adjacent passage 20. This distortion lifts a portion of the sealing rings 26 from the circumference of the rigid capillary tube 24 and allows the flushing solution to by-pass this capillary and thereby rapidly fill tubes 14 and 12 to make sure that there is no air present in any of the catheter system. While the invention has been described pria- rily in connection with a continuous flushing catheter system it can be utilized as a valve for other systems. In this case the rigid central capillary tube can be replaced b a solid pice of glass for example. The valve can then be used as an on and off valve. The present invention provides a valve of extremely simple molded construction having a normally closed position which can be operated very simply by an operator squeezing lever ar 36 towards valve portion 22. This permits one hand operation of the device with complete assurance that the valve will fast flush and the system will be completely sealed when the lever arm is permitted to return to its non-deforming position.

Claims: \\HAT 1S Ci#Al#ED IS: 1. A valve comprising a relatively rigid central portion, a flexible outer portion surrounding said central portion and having a sealing surface which engages said central portion around its whole circumference in liquid sealing relationship, and an integral pair of lever arms molded as part of said body and extending from said body radially of its axis, said lever arms -comprising means for transmitting a shape-deformig force to said flexible outer portion to lift a portion of said sealing surface out of contact with the rigid cylinder, to permit passage of liquid through said valve. 2. The valve of claim 1 wherein the rigid central portion is cylindrical and the flexible outer portion contains a circular sealing ring and wherein the deformation force converts the sealing surface from a circle to an oblong to lift a portico of the sealing surface from the inner cylinder. 3. The valve of claim 1 wherein the rigid central portion comprises a capillary tube.

Inventors: HICKS, ROGER D.
Applicants: NORTON COMPANY
Application year: 1979
Main classification: A61M5
IPC codes: A61M39, F16K7, A61B1