A medical catheter is a small tube generally designed for insertion into a cavity, duct or vessel in the body of a patient. Once in place, the medical catheter enables the injection of a fluid into the body or the withdrawal of a fluid from the body. Alternatively, the medical catheter can establish or maintain the patency of a fluid passageway within the body into which the catheter is placed. As such, catheters have utility for a broad range of medical treatment applications.
An exemplary medical treatment application, wherein a catheter is employed to inject a fluid into the body, is the post-operative treatment of a surgical wound. Upon completion of a surgical procedure, one end of the catheter is maintained internally in the patient at or near the surgical wound site while the opposite end of the catheter extends externally out of the body. The external end of the catheter is fluid communicatively connected to a treatment fluid reservoir or a fluid delivery device, such as an infusion pump, a syringe, or a fluid-filled bladder. Connecting the catheter to the reservoir or delivery device enables the practitioner to deliver a treatment fluid to the wound site. The treatment fluid can be an analgesic to manage post-operative pain or any other type of fluid medication which promotes post-operative healing of the surgical wound site.
A coupling or fitting is generally required at the external end of the catheter to enable serial connection of the catheter to the reservoir or delivery device. However, it is often desirable to maintain the external end of the catheter free from attachment to any such connection means while the opposite internal end of the catheter is being placed at the surgical wound site so that the connection means does not interfere with the catheter placement procedure. In such cases, the connection means is preferably installed on the external end of the catheter after placement of the catheter in the treatment site has been completed. The connection means provides a link in the fluid flowpath between the reservoir or delivery device and the treatment site. In particular, the connection means couples the external end of the catheter with an adjoining member of the fluid flowpath which is typically the outlet of the reservoir or delivery device or the outlet of an extension tube provided in the fluid flowpath between the catheter and the remotely positioned reservoir or delivery device. To achieve effective coupling between the external end of the catheter and the adjoining member, the connection means desirably attaches to the external end of the catheter and has a coupling element which can be mated with a corresponding coupling element of the adjoining member.
The attachment function of the connection means may be performed by a fitting which is secured to the external end of the catheter by compression. However, the catheter must have sufficient girth and rigidity to resist occlusion when subjected to compression. Unfortunately, the characteristics of relatively large diameter and high degree of rigidity are generally undesirable for the post-operative treatment function of the catheter. A catheter having a relatively small diameter is more desirable for the post-operative treatment function because it minimizes disruption of the treatment site and promotes healing. A catheter having a relatively high degree of flexibility is also more desirable for the post-operative treatment function because it permits the catheter to follow a tortuous path with a minimal risk of kinking and blockage of treatment fluid flow. However, if a compression force sufficient to adequately secure the catheter to the connection means is applied to a small diameter, highly flexible tube of the type preferred for use as a medical catheter, the connection means is likely to pinch the catheter resulting in partial or total occlusion of the catheter. Conversely, if the compression force is reduced sufficiently to avoid occlusion of the catheter, the catheter is likely to disengage from the connection means at the point of attachment under the stresses of normal use. Neither likelihood is acceptable if effective post-operative treatment of the surgical wound site is to be achieved.
The present invention recognizes a need for a tubing connector which can be securely, yet releasably, installed on the external end of a small diameter, highly flexible catheter without substantially occluding the catheter or otherwise disrupting fluid flow through the catheter. Accordingly, it is an object of the present invention to provide an effective tubing connector for releasable attachment to an end of a tube. More particularly, it is an object of the present invention to provide a tubing connector which can be securely, yet releasably, installed on the end of a catheter without substantially disrupting fluid flow through the catheter. It is another object of the present invention to provide a tubing connector which can be securely installed on the end of a catheter after the opposite end of the catheter has been placed in a treatment site of a patient. It is yet another object of the present invention to provide a tubing connector which can effectively couple a catheter with an adjoining member of a fluid flowpath. It is still another object of the present invention to provide a tubing connector which can be utilized effectively with a small diameter, highly flexible catheter.
These objects and others are accomplished in accordance with the invention described hereafter.