Patent Publication Number: US-2012035593-A1

Title: Enteral connector

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/371,271, filed Aug. 6, 2010, the entirety of which is hereby incorporated herein by reference for all purposes. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to the field of medical devices and procedures, and more particularly to an improved connector for enteral, nasogastric and/or gastric feeding tubes, extension tubes, and/or other fluid delivery conduit connections, as well as to associated systems and methods utilizing such a connector. 
     BACKGROUND 
     Enteral feeding tubes are used to provide nutrition to human or animal patients who can not obtain sufficient nutrition by eating through the mouth by swallowing. Nasogastric feeding tubes are inserted through the nares (nostril), through the esophagus, and into the stomach of the patient. Gastric feeding tubes may be percutaneously inserted into the stomach. As used herein, enteral, nasogastric, gastric and other nutrient delivery components are collectively referred to as enteral components. The distal or discharge end of the feeding tube is positioned internally and delivers liquid nutrients into the stomach, while the proximal end of the feeding tube is positioned externally for connection to a nutrient source. 
     Once placed, a feeding tube may remain in the patient for several weeks or more, depending upon the continued need for enteral feeding; whereas the nutrient source is typically replaced more frequently, for example on a daily basis. For example, in enteral feeding of infants, the nutrient source may be a container of breast milk or formula, which is replaced one or more times per day. To facilitate replacement of the nutrient source without disturbing the placement of the feeding tube, the proximal or external end of a feeding tube commonly comprises a female enteral connector hub into which a male connector element or enteral tip may be removably coupled, typically by an interference fit resulting from a progressive taper provided on the enteral tip. 
     Repeated replacement of the nutrient source can lead to stretching of the female enteral connector hub by the enteral tip, potentially resulting in loss of the interference fit required for a reliable connection at the enteral coupling between the hub and tip. Over-insertion of the male enteral tip into the female connector hub can exacerbate the potential for stretching and permanent deformation of the hub, due to the taper of the enteral tip having an increasing diameter the further it is inserted. Loss of a reliable connection at the enteral coupling typically necessitates replacement of the feeding tube, which may be traumatic for some patients or interfere with a normal feeding regimen, and is generally undesirable. 
     Accordingly, it can be seen that needs exist for improvements to enteral feeding systems and methods. It is to the provision of an improved enteral connector and to improved feeding systems and methods meeting these and other needs that the present invention is primarily directed. 
     SUMMARY 
     In example embodiments, the present invention provides an improved connector for enteral feeding. In one aspect, the present invention relates to a male connector element for coupling with a female connector hub. The male connector element includes a tip portion having a tip length substantially greater than a receiver length of the female connector hub, thereby preventing over-insertion. 
     In another aspect, the invention relates to an enteral connector or extension tube. The enteral connector tube includes a male connector element affixed to a first end of a tube and a female connector element affixed to a second end of the tube. The male connector element includes a tip portion having a tip length substantially greater than a corresponding receiver length of a female connector hub, thereby preventing over-insertion into the female hub. 
     In another aspect, the invention relates to an enteral coupling comprising a male connector element releasably coupled to a cooperating female connector hub. The male connector element includes a tip portion having a tip length substantially greater than a corresponding receiver length of a female connector hub, thereby preventing over-insertion into the female hub. 
     In still another aspect, the invention relates to a male connector element having a coupling segment for detachable coupling with a female receiver. The coupling segment defines a male coupling length in an axial direction and a male coupling outer dimension transverse to the axial dimension. The female receiver defines a female coupling length in the axial direction and a female coupling outer dimension transverse to the axial dimension. The male coupling length is greater than the female coupling length, and the male coupling outer dimension and the female coupling outer dimension are selected to form a sealing engagement therebetween without exceeding an elastic deformation limit of the female receiver. 
     In another aspect, the invention relates to a method of detachably coupling a male connector with a female connector. The method includes insertion of a coupling segment of the male connector into a receiver of the female connector to an insertion depth. The receiver of the female connector defines a female coupling length in an axial dimension of no greater than the insertion depth, and the coupling segment of the male connector defines a male coupling length in the axial dimension of greater than the insertion depth. 
     These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an enteral connector and delivery tube according to an example embodiment of the present invention. 
         FIG. 2  shows the enteral connector of  FIG. 1  and a female connector hub, in an unconnected or detached state. 
         FIG. 3  shows the enteral connector of  FIG. 1  partially inserted into the female connector hub. 
         FIG. 4  shows the enteral connector of  FIG. 1  partially inserted into the female connector hub, with the female connector hub partially cut away to show the internal connection. 
         FIG. 5  shows the enteral connector of  FIG. 1  further inserted into the female connector hub. 
         FIG. 6  shows the enteral connector of  FIG. 1  fully inserted into and engaged with the female connector hub. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein. 
     Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
     With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views, an enteral connector tube  10  according to an example embodiment of the invention generally comprises a flexible tube or delivery conduit  20  having a female connector element or coupling member  30  at one end and a male connector element or coupling member  50  at the other end. The female connector element  30  is configured for removable attachment to, for example, a metered syringe, dispenser, bag, or other container of breast milk, formula or other nutrient source. 
     The male connector element or coupling member  50  comprises a stepped profile having four segments  54 ,  56 ,  58 ,  60  of progressively decreasing diameter moving from its proximal end to distal tip. In alternate embodiments, one or both of the intermediate steps or segments  56 ,  58  may optionally be omitted, resulting in a two or three-segmented coupling member. The proximal end of the male coupling member  50  comprises a receiver  70  for attachment of the tube  20 , optionally including a strain-relief bushing  72 , and a flange  74 . An internal bore or channel extends axially and lengthwise through the male coupling member  50 , providing fluid communication from the tube  20  through a discharge opening  80  at the tip of the distal segment  60 . 
     The distal tip portion or coupling segment  60  of the male coupling member  50  preferably tapers slightly (about 1°-3° of taper, preferably about 1.25°) from a larger outside diameter at the intersection with third segment  58  to a smaller outside diameter of about 4.5 mm-5.0 mm, preferably about 4.7 mm, at its tip, and has a radiused outer chamfer at the tip. The distal segment  60  preferably has a length L M  of at least about 10 mm, and preferably at least about 12 mm (for example about 12.5 mm in the depicted embodiment), or in any event a length L M  greater than the length L F  of the female receiver into which the male coupling member  50  is to be connected (see  FIG. 4 ). For example, if a female length L F  of about 8.5 mm is adopted as a standard for a particular coupling set, the male length L M  would be at least about 8.5-9.0 mm or more. 
       FIGS. 3-6  show a sequence of progressive axial (along axis A as shown in  FIG. 4 ) insertion of the male coupling member  50  into the receiver of a cooperating female coupling hub  40 . The depicted form of female hub  40  is by way of example only, and the male coupling member of the invention is preferably adaptable for universal use with different types or formats of female hub components produced by various manufacturers. The female hub  40  is, for example, the proximal end of an enteral feeding tube positioned external of a patient, and having its distal or discharge end positioned internally to deliver liquid nutrients into the patient&#39;s stomach. 
     The male coupling member  50  may be inserted into the receiver of the female hub  40  as shown in the sequence of  FIG. 4  (partially inserted) to  FIG. 5  (further inserted) to  FIG. 6  (fully inserted). Typically it will be unnecessary to fully insert the male coupling member, as an adequate interference fit connection will be obtained before full insertion. The male coupling member is disconnected and removed from the female hub by reversing the sequence of operation. 
     Progressive insertion of the male coupling member  50  into the receiver of the cooperating female hub or coupling member  40  requires progressively increasing application of force, due to the tapered profile of the distal or tip segment  60  of the male coupling member. Over-insertion of the male coupling member into the receiver of the cooperating female hub or coupling member is prevented by means of the length L M  of the distal segment  60  of the male coupling member being greater than the length L F  of the receiver chamber of the female coupling member. As such, the tip of the male coupling member abuts a shoulder or other stop member within the receiver chamber of the female coupling member before the larger diameter third segment  58  of the male coupling member enters the receiver of the female coupling member. 
     The outer diameter D M  or (other outer dimension transverse to the axis A, if the coupling member is not circular) and degree of taper of the distal segment  60  of the male coupling member are selected to provide an interference fit and sealing connection within the inner diameter of the receiver chamber of the female coupling member without exceeding the elastic deformation limit of the female coupling member, when inserted to its maximum depth, so as not to produce a permanent deformation of the female coupling member which could result in loss of a reliable connection leading to the need for replacement of a feeding tube. 
     While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.