HK1211880B - Overmolded medical connector tubing and method - Google Patents

Description

Overmolded medical connector tube and method

Background

Technical Field

The present invention relates to the medical field, and in particular to medical tubing used in the medical field for conducting fluid to and from a patient and/or between medical devices, which may include one or more end connectors for establishing a fluid connection for conducting fluid to and from the patient and the medical device.

Description of the Related Art

Numerous examples of medical tubing and connectors for medical tubing are found in the medical field. For example, U.S. patent application publication No. 2012/0024411 to Hanh et al generally relates to tubes for connecting components of liquid chromatography and other analytical systems, and discloses a tube composed of three distinct sections including an outer layer, an inner layer, and a passageway defined by the inner layer. The tube includes retention features such as barbs machined onto the end of the outer layer. The inner layer projects from the barb, and the barb and the projecting portion of the inner layer are overmolded with the tip.

U.S. patent application No. 2011/0306826 to Franklin (Franklin) et al discloses an implantable device for use in a medical system to protect a tube from puncture. In one embodiment, a shield is provided that is overmolded onto a tube or onto a housing connected to an end of the tube and the tube.

U.S. patent application No. 2011/0127186 to ens (ens) et al discloses a packaging tube for extending medical devices, such as catheters and guidewires, wherein a series of plastic clips are overmolded onto the tube. Each of the clips surrounds an adjacent section of the tube such that each clip forms a closed loop around the outer surface of the tube at each section where the clip is located.

U.S. patent application publication No. 2010/0130922 to bloog (Borlaug) et al discloses a medical fluid injection device including a fluid connector made of an overmolded thermoplastic elastomer.

U.S. patent application publication No. 2010/0063481 to Hoffman et al discloses a flow path assembly for use in a fluid path for delivering a medical fluid. This publication discloses a tube connected at one end to a syringe outlet and having a compressible sealing element connected to the opposite end. The sealing element may be formed of an elastomeric material and is generally cylindrical in shape and sized to be concentric with the tube. The elastomeric sealing element may be overmolded onto the tube to eliminate the need for adhesives.

U.S. patent application publication No. 2010/0022966 to Kennard et al discloses a fluid delivery device that includes a tube having an overmolded region and to which a barbed connector tip may be secured by a press-fit thereon.

U.S. patent application publication No. 2008/0284167 to Lim (Lim) et al discloses a fitting for connecting pipes. In one embodiment, the fitting is formed by injection molding, then a material is overmolded or co-molded onto the fitting to form the extension, and then a tube end is inserted into the fitting to direct fluid through the fitting.

U.S. patent application publication No. 2007/0215268 to Pingleton discloses a method of applying a braid to a tube and fusing the braid to the tube to prevent kinking or the like thereof. The braid may be insert molded or over molded to the tube.

U.S. patent application publication No. 2006/0170134 to Rowley et al discloses a method of injection overmolding a connector with a pipe section.

Summary of The Invention

One embodiment described herein relates to a high pressure medical connector tubing assembly comprising a tubing element comprising opposing tube ends and a passageway therethrough; an end element overmolded onto at least one of the opposing tube ends, the end element including a looped end portion having a preselected length; and a connector element including a connector hub defining a receiving cavity in which the tube end with the overmolded end element is fixedly secured. The preselected length of the looped end portion can be used to pre-control the axial location of stress concentrations in the connector hub.

The tube end with the overmolded end element is fixedly secured in the receiving cavity by solvent bonding. The end element may be formed with at least one external indicator to visually identify the depth of insertion of the tube end with the overmolded end element into the receiving cavity. The tube element may comprise a braided tube formed of an inner braided layer encapsulated by a flexible polymer layer. The connector element may include a connector port defining a fluid passageway. The annular end portion may define a tapered inlet tapering from the fluid passageway to the passageway in the pipe element. The inlet may taper inwardly, for example at an angle between 0 ° and 80 °. An end element is overmolded onto each of the tube ends of the tube element. The connector element may include a pair of connector elements, and the tube ends each have an overmolded end element fixedly secured in a receiving cavity of the connector elements, respectively. The tube element may comprise a braided tube formed of an inner braided layer encapsulated by a flexible polymer layer.

Another embodiment relates to a method of forming a high pressure medical connector tubing assembly, the method comprising providing a tubing element comprising opposing tube ends and a passageway therethrough; overmolding a tip element onto at least one of the opposing tube ends, the tip element including a ring-shaped tip portion having a preselected length; a connector element is provided that includes a connector hub defining a receiving cavity, and a tube end with the overmolded end element is secured in the receiving cavity. The preselected length of the looped end portion can be used to pre-control the axial location of stress concentrations in the connector hub.

Securing the tube end with the overmolded end element in the receiving cavity may include solvent bonding. The end element may be formed with at least one external indicator to visually identify the depth of insertion of the tube end with the overmolded end element into the receiving cavity. The tube element may comprise a braided tube formed of an inner braided layer encapsulated by a flexible polymer layer. The connector element may include a connector port defining a fluid passageway. The annular end portion may define a tapered inlet tapering from the fluid passageway to the passageway in the pipe element. The inlet may taper inwardly, for example at an angle between 0 ° and 80 °. An end element may be overmolded onto each of the tube ends of the tube element. The tube ends may each have an overmolded end element and be fixedly secured in the receiving cavities of the connector elements, respectively. The tube element may comprise a braided tube formed of an inner braided layer encapsulated by a flexible polymer layer.

Other details and advantages of the present invention will be appreciated from a reading of the following detailed description in conjunction with the drawings.

Brief description of the drawings

Fig. 1A-1C are perspective end views of a known medical tube used in the medical field.

Fig. 2 is a cross-sectional view of an overmolded medical connector tube assembly, according to an embodiment.

Fig. 3 is an isometric view of the end portion of a tube member used in the medical connector tube assembly shown in fig. 2.

Fig. 4 is a Finite Element Analysis (FEA) diagram of an exemplary connector element of the medical connector tube assembly shown in fig. 2 when assembled with an overmolded tube element.

FIG. 5 is a Finite Element Analysis (FEA) diagram of an assembled connector element and pipe element when under fluid pressure.

Fig. 6 is a cross-sectional view of the medical connector tube assembly of fig. 2 according to a first exemplary modification of the assembled connector element and tube element.

Fig. 7 is a cross-sectional view of the medical connector tube assembly of fig. 2 according to a second exemplary modification of the assembled connector element and tube element.

Fig. 8 is a cross-sectional view of the medical connector tube assembly of fig. 2 according to a second exemplary modification of the assembled connector element and tube element.

Description of the preferred embodiments

For purposes of the following description, spatially oriented terms as used herein should be referenced with respect to the described embodiment as it is oriented in the figures or otherwise described in the following detailed description. It should be understood, however, that the embodiments described below may assume many alternative variations and configurations. It is also to be understood that the specific components, devices, features and operational sequences illustrated in the accompanying drawings and described herein are simply exemplary and should not be considered as limiting.

Referring to fig. 1A-1C, in the medical field, there are several options available for high pressure tubes with connector tips. In fig. 1A, a medical tube 10 is shown in the form of a high pressure PVC tube. In this known arrangement, once dedicated, the production costs are considered low, but expensive production injection moulding moulds should be in place. Medical tubing 10 relies on the incorporation of a plasticizer to render the tubing a non-rigid single wall plastic polymer. Such plasticizers have yet to be carefully investigated in the medical field for biocompatibility and possible migration into the fluid pathway. Additionally, operating pressures are typically limited to 1000psi due to the lower tensile strength of PVC relative to engineering grade plastics. In typical applications, the luer hub may be solvent bonded to the ends of the medical tube 10. Solvent bonding is known to cause luer stress cracking and crevice problems where fine crevices appear in the surface of the luer hubs when they are solvent bonded to the ends of medical tubing 10. This induced cracking is due to the high stresses that are generated with high durometer rigid tubing when applying the end connector to the ends of the medical tubing 10 (requiring an interference fit and solvent bonding). These interference fits and the attendant solvent bonding impacts can lead to air ingress and or pressure failure. Ultraviolet (UV) adhesive bonding is an unreliable alternative to solvent bonding because plasticizers corrode the UV adhesive and can cause the bonded joint to delaminate after sterilization. Luer connector fittings may be insert molded onto these ends of medical tubing 10, but production costs increase and the geometry of the connector is limited to a simple in-line fluid path.

In fig. 1B, a medical tube 20 is shown in the form of a coextruded high pressure connector tube. The medical tube 20 has a high strength inner wall 22 formed of a suitable polymer coaxially surrounded by a flexible outer wall 24 formed of another polymer such that the medical tube can achieve a 1200psi rating, but retains some degree of flexibility. In this embodiment, the luer hub may be solvent bonded to the ends of the medical tube 20, but direct solvent bonding to the medical tube 20 may also cause luer hub stress cracking and splitting issues in a manner similar to the medical tube 10 described previously. This induced cracking is due to the high stresses that develop with medium aggregate hardness tubes when applying end connectors to the ends of medical tubes 20 (requiring an interference fit and solvent bonding). These interference fits and the attendant solvent bonding impacts can lead to air ingress and or pressure failure. Again, Ultraviolet (UV) adhesive bonding is not a reliable alternative to solvent bonding because UV adhesives require a gap between medical tubing 20 and the luer hub because optimal strength and lifetime are limited due to adhesive bonding breaking down over time. Luer connector fittings may be insert molded onto these ends of medical tubing 20, but, on the other hand, production costs increase and the geometry of the connector is limited to a simple in-line fluid path.

In fig. 1C, a medical tube 30 in the form of a braided high-pressure connector tube is shown. The medical tube 30 has a high strength inner braid 32 formed of a suitable polymer encapsulated by a flexible polymer layer 34 to achieve a pressure rating of 1200psi and is highly flexible. The inner braid 32 keeps the medical tube 30 from swelling and cracking, but may inhibit visual fluid path clarity, often used to ensure bubble visualization after air purge operations. In addition, when cutting the braided medical tube 30, it is desirable to isolate the cutting tip from high pressure in order to keep fluid pressure from wicking into the braid (which may cause pressure failure of the medical tube 30). As in the previously discussed embodiments, direct solvent bonding can cause luer hub stress cracking and crevice problems. This induced cracking is due to high stresses that are generated when the end connector is applied to the ends of the medical tube 30 and requires an interference fit and solvent bonding. The stresses are high due to the level of interference required to squeeze the braided medical tube 30 into the luer hub and to maintain the pressurized fluid from wicking into the braided tips (which may cause pressure failure of the medical tube 30). Again, Ultraviolet (UV) adhesive bonding is not a reliable alternative to solvent bonding because UV adhesives require a gap between the medical tubing 30 and the luer hub for optimal strength and shelf life is limited due to the breakdown of the adhesive bond over time. Luer connector fittings may be insert molded onto these ends of medical tubing 30, but on the other hand, production costs increase and the geometry of the connector is limited to a simple in-line fluid path.

Referring to fig. 2-3, a high pressure medical connector tubing assembly 100 (hereinafter "connector tubing 100") according to one embodiment is shown. Connector tube 100 generally includes a tube member 102, which may be a co-extruded or braided tube member in accordance with known tube members found in the medical field. The pipe element 102 includes opposite pipe ends 104, 106 and a defined central passage 108 for conducting fluid therethrough. The tube member 102 comprises a braided tube in the depicted embodiment. The pipe element 102 includes a high strength inner braid 110 formed of a suitable polymer encapsulated by a flexible polymer layer 112 to achieve a pressure rating of 1200psi and is highly flexible.

With the present pipe element 102, an end piece or element 114 may be applied to the opposing pipe ends 104, 106 of the pipe element 102 to form a composite structure. These end elements 114 each include an annular or tubular body 116 having an annular or tubular end portion 118 and are overmolded onto the opposing tube ends 104, 106, respectively, of the tube element 102. The tubular body 116 of the end element 114 may be made of a soft plastic material, such as polyurethane, or any flexible thermoplastic material compatible with the underlying pipe element 102 to facilitate coating onto the pipe ends 104, 106 of the pipe element 102. Each of the tubular bodies 116 may be shaped such that the end portions 118 define tapered inlets 120 formed with a predetermined transition angle or taper angle (such as between 0 ° and 80 °, for example). The outer surface 122 of the tubular body 116 of each of these end elements 114 may be formed with one or more external indicators 124, such as annular grooves and the like, to indicate the desired or designated insertion point or distance into which the composite tube end 104, 106 with the overmolded end element 114 is to be mated with or received by the connector element 140, 160, as described herein. The overmolded end elements 114 are advantageous in one aspect in that the end elements 114 seal the cut tube ends 104, 106 of the tube element 102 when applied. When cutting a braided medical tube containing the tube element 102, it is desirable to isolate the cutting tip from high pressure in order to keep fluid pressure from wicking into the braid (which could cause pressure failure of the tube element 102). The overmolded end elements 114 are advantageous in that the end elements 114, when applied, seal the cut tube ends 104, 106 of the braided tube element 102.

As indicated, the connector elements 140, 160 are applied to the opposing composite tube ends 104, 106, respectively, of the tube element 102 having the overmolded end element 114. The connector elements 140, 160 may be conventional injection molded luer connectors well known in the medical arts, and the following discussion of specific features of the connector elements 140, 160 is not intended to be limiting with respect to possible luer connector elements or tip configurations that may be used with the tube element 102. Moreover, any particular discussion hereinafter relating to one of the connector elements 140, 160 is equally applicable to the opposing connector element 140, 160, and the concepts described herein may be further applied to any suitable known luer connector element known in the medical arts. The particular configuration of the connector elements 140, 160 shown in fig. 2 and 3-8 is intended to be exemplary only.

The connector element 140 includes a connector hub 142 defining a receiving recess or cavity 144 for receiving the composite tube end 104 with the overmolded end element 114. The connector hub 142 may include a connector port or portion 146 adapted to connect to an upstream or downstream fluid directing element (not shown). As shown in fig. 2, the tapered inlet 120 defined by the end portion 118 of the overmolded end element 114 is formed at a transition or taper angle of any suitable angle, such as between 0 ° and 80 °, for example, to allow for a smooth fluid transition between the fluid passage 148 in the connector port 146 and the tapered inlet 120, and between the tapered inlet 120 and the central passage 108 in the tube element 102. The tapered inlet 120 desirably maintains laminar flow conditions at a first transition point or seam 150 between the fluid passage 148 and the end portion 118 of the overmolded end element 114 defining the tapered inlet 120, and at a second transition point or seam 152 between the end portion 118 of the overmolded end element 114 defining the tapered inlet 120 and the central passage 108 in the tube element 102. The tapered inlet 120 generally provides a smooth transition between the fluid passage 148 in the connector port 146 to the central passage 108 in the tube element 102, and helps to minimize air pockets (air trap) or stagnation points by providing a smooth transition of fluid at a first transition point or seam 150 between the fluid passage 148 and the tapered inlet 120 defined by the end portion 118 of the overmolded end element 114, and at a second transition point or seam 152 between the tapered inlet 120 defined by the end portion 118 and the central passage 108 in the tube element 102. The composite tube end 104 of the tube element 102 with the overmolded end element 114 may be secured in the receiving groove or cavity 144 by solvent bonding and similar joining methods, such as laser welding. These external indicators 124 disposed on the tubular body 116 of the tip element 114 on the tube end 104 of the tube element 102 provide a visual indication of insertion of the composite tube end 104 and overmolded tip element 114 into the receiving cavity 144 of the connector element 140 to a desired insertion depth, and further visually confirm a solvent bonded interference fit between the tip element 114 and the connector element 140, and also help prevent under-insertion (under-insertion) of the composite tube end 104 and overmolded tip element 114 into the receiving cavity 144. A solvent bonded connection with an interference fit between the composite tube end 104 and the overmolded end element 114 and the receiving cavity 144 of the connector element 140 is desirable.

The connector element 160 includes a connector hub 162 defining a receiving recess or cavity 164 for receiving the opposing composite tube end 106 with the overmolded end element 114. Connector hub 162 may include a connector port or portion 166 adapted to connect to an upstream or downstream fluid directing element (not shown). As shown in fig. 2, the tapered inlet 120 defined by the end portion 118 of the overmolded end element 114 is formed at a transition or taper angle of any suitable angle, such as 0 ° to 80 °, to allow for a smooth fluid transition between the fluid passage 168 in the connector port 166 and the tapered inlet 120, and between the tapered inlet 120 and the central passage 108 in the tube element 102. The tapered inlet 120 desirably maintains laminar flow conditions at a first transition point or seam 170 between the fluid passageway 168 and the end portion 118 of the overmolded end element 114 defining the tapered inlet 120, and at a second transition point or seam 172 between the end portion 118 of the overmolded end element 114 defining the tapered inlet 120 and the central passageway 108 in the tube element 102. The tapered inlet 120 generally provides a smooth transition between the fluid passageway 168 in the connector port 166 to the central passageway 108 in the tube element 102, and helps to minimize air pockets (air trap) or stagnation points by providing a smooth transition of fluid at a first transition point or seam 170 between the fluid passageway 148 and the tapered inlet 120 defined by the end portion 118 of the overmolded end element 114, and at a second transition point or seam 172 between the tapered inlet 120 defined by the end portion 118 and the central passageway 108 in the tube element 102. The composite tube end 106 of the tube element 102 with the overmolded end element 114 may be secured in the receiving groove or cavity 164 by solvent bonding and similar joining methods, such as laser welding. These external indicators 124 disposed on the tubular body 116 of the tip element 114 on the tube end 106 of the tube element 102 provide a visual indication of insertion of the composite tube end 106 and overmolded tip element 114 into the receiving cavity 164 of the connector element 160 to a desired insertion depth, and further visually confirm a solvent bonded interference fit between the tip element 114 and the connector element 160, and also help prevent under-insertion (under-insertion) of the composite tube end 106 and overmolded tip element 114 into the receiving cavity 164. A solvent bonded connection with an interference fit between the composite tube end 104 and the overmolded end element 114 and the receiving cavity 164 of the connector element 160 is desirable.

With further reference to fig. 4, a Finite Element Analysis (FEA) diagram of the connector element 140 is shown having the tube end 104 and the overmolded tip element 114 fitted into and secured within the receiving cavity 144 of the connector element 140 by the interference fit, solvent bonded connection of fig. 4, the FEA diagram of the connector hub 142 of the connector element 140 showing the location of the stress concentration S in the connector hub 142 when seating and securing the composite tube end 104 and the overmolded tip element 114 in the receiving cavity 144 of the connector element 140. In accordance with the present disclosure, the location or positioning of the stress concentration S may be varied along the axial direction of the connector hub 142 to be positioned or seated at a preselected axial location along the axial length L1 in the receiving cavity 144 of the connector hub 142. This axial position may be preselected or "pre-controlled" so as to position the region of stress concentration S at any desired location generally along axial length L1, and typically at a location away from the point of stress riser (e.g., a hard interface, corner, edge, sharp or protruding surface feature, or material weakness). In this manner, the stress concentration S in the connector hub 142 may be set at a preselected or "pre-controlled" axial position, and thus, the stress concentration in the connector element 140 may be "pre-controlled" in advance. Such stress concentrations S may induce cracks and fissures in the connector hub 142 when the tube end 104 and the overmolded end element 114 are fitted in the receiving cavity 144 and the tube element 102 is repeatedly pressurized. The present disclosure provides a method and physical arrangement whereby the location of stress concentration S can be preselected or "pre-controlled" so as to be located along a preselected axial location of connector hub 142 so as to avoid stress risers at hard interfaces, corners, edges, sharp or protruding surface features, or material weaknesses, and along an axial location of connector hub 142 having a more "flat" surface feature and generally lacking the aforementioned stress inducing features.

In fig. 5, a FEA view of the overmolded end element 114 is provided showing the overmolded end element 114 seated and secured in the receiving cavity 144 of the connector element 140. FIG. 5 shows the stress concentration S in the end element 114 when the inner tube element 102 is under pressure of about 1200 psi. The stress concentration S in the tip element 114 is typically most prominent or at a maximum at the location where the tube end 104 is seated or fitted in the tip element 114. In fig. 5, when the pipe element 102 is under pressure, the pressure causes the pipe element 102 and overmolded end element 114 to stretch over the pipe end 104 within the connector hub 142 of the connector element 140. The tube end 104, albeit under pressure, should reside within the body of the connector hub 142 (e.g., within the receiving cavity 144) to prevent breakage, and this positioning is accomplished by preselecting or "pre-controlling" the axial positioning of the tube end 104 within the overmolded end element 114 and by preselecting the hardness of the material forming the overmolded end element 114.

As will be generally understood from a review of fig. 4-5 together, when assembled in the receiving cavity 144 and under pressure, the stress concentration S in the overmolded tip element 114 is generally radially coextensive with the stress concentration S in the connector hub 142 of the connector element 140. Thus, preselecting or "pre-controlling" the location of the stress concentration S in the overmolded end element 114 also preselecting or "pre-controlling" the location of the stress concentration S in the connector hub 142, and this location is generally dependent upon the axial positioning of the tube end 104 within the overmolded end element 114. As previously mentioned, it is desirable to pre-select or "pre-control" the location of the stress concentration S in the connector hub 142 such that this pre-selected or "pre-controlled" location avoids stress risers at hard interfaces, corners, edges, sharp or protruding surface features, or material weaknesses, and, alternatively, is located along an axial location of the connector hub 142 having a more "flat" surface feature and generally lacking the aforementioned stress inducing features.

Fig. 6-8 illustrate three (3) exemplary embodiments of the connector tube 100 in which the tube end 104 is positioned at different axial locations within the overmolded end element 114, thereby changing the axial location of the stress concentration S in the overmolded end element 114, and thus, the connector hub 142 is positioned radially outward from the overmolded end element 114. As will be appreciated from a sequential review of fig. 6-8, the axial position of the tube end 104 within the overmolded end element 114 is changed by shortening or lengthening the axial length L2 of the end portion 118 of the tubular body 116 of the end element 114. From fig. 6-8, it will be understood that the connector elements 140, 160 may have different configurations, and the versions of the connector elements 140, 160 in fig. 2 and 6-8 are intended to be exemplary only. Fig. 6 shows the tip portion 118 having the shortest axial length L2, such that the axial position of the tube end 104 within the tip element 114 is the closest of the three (3) instances to the fluid passageway 148 in the connector port 146. Thus, the radial stress concentration in the connector hub 142 in fig. 6 is closest to the connector port 146 of the three (3) examples. Fig. 7 shows the tip portion 118 having a slightly longer axial length L2 such that the axial position of the tube end 104 within the tip element 114 is spaced slightly farther from the fluid passageway 148 in the connector port 146. Thus, the radial stress concentration in the connector hub 142 in fig. 7 is now farther away from the connector ports 146 of the three (3) examples. Fig. 8 shows the end portion 118 having an even longer axial length L2 such that the axial position of the tube end 104 within the overmolded end element 114 is spaced even farther from the fluid passageway 148 in the connector port 146 of the present three (3) examples. Thus, the radial stress concentration in the connector hub 142 in fig. 8 is now the farthest from the connector port 146 of the three (3) examples. By changing the radial position of the tube end 104 within the overmolded tip element 114 (which may be accomplished by shortening or lengthening the axial length L2 of the end portion 118 of the tubular body 116 of the tip element 114), the stress concentration in the connector hub 142 may be axially displaced along the axial length L1 of the receiving cavity 144 (and thus along the axial length of the connector hub 142). Thus, the location of stress concentrations in the connector hub 142 may be preselected or "pre-controlled" to avoid stress risers at hard interfaces, corners, edges, sharp or protruding surface features, or material weaknesses, and, alternatively, at a specified axial location along the connector hub 142 that desirably has a more "flat" surface feature and is generally free of the aforementioned stress inducing features. While the foregoing discussion references connector element 140, the foregoing discussion applies equally to connector element 160 or any suitable luer connector element or hub known in the medical arts. The present disclosure allows for pre-selecting or "pre-controlling" the location of radial stress concentrations in the medical connector element by adjusting the axial length of the end portion 118 of the over-molded element 114 on the tube ends 104, 106.

While several embodiments of the high pressure medical connector tube assembly and components or elements thereof are shown in the drawings and described above in detail, other embodiments will be apparent to and are readily implemented by those skilled in the art without departing from the scope and spirit of the present invention. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (18)

1. A high pressure medical connector tubing assembly comprising:

a tube element including opposite tube ends and a passageway therethrough;

a tip element overmolded onto at least one of the opposing tube ends, the tip element including an annular end portion having a preselected axial length, the annular end portion defining an inlet; and

a connector element including a connector hub defining a receiving cavity in which such tube end with the end element overmolded is fixedly secured, the connector element including a connector port defining a fluid passageway;

wherein the axial location of the radial stress concentration in the connector hub is preselected by shortening or lengthening the axial length of the annular end portion in the receiving cavity; and is

Wherein the inlet and the fluid passageway have a common inner diameter and are proximate to define a smooth transition seal between the fluid passageway and the inlet to maintain a laminar flow condition across the smooth transition seal.

2. A high pressure medical connector tubing assembly as claimed in claim 1, wherein the tube end with the overmolded end element is fixedly secured in the receiving cavity by solvent bonding.

3. A high pressure medical connector tubing assembly as claimed in claim 1, wherein the end element is formed with at least one external indicator to visibly identify the depth of insertion of the tube end with the overmolded end element into the receiving cavity.

4. A high pressure medical connector tubing assembly as claimed in claim 1, wherein the tubing element comprises a braided tube formed of an inner braid encapsulated by a flexible polymer layer.

5. A high pressure medical connector tubing assembly as in claim 4, wherein the inlet tapers from downstream of the smooth transition seal to the passageway in the tubing element.

6. A high pressure medical connector tubing assembly as claimed in claim 5, wherein the inlet tapers at an angle of substantially between 0 ° and 80 °.

7. A high pressure medical connector tubing assembly as claimed in claim 1, wherein an end element is overmolded onto each of the tube ends of the tubing element.

8. A high pressure medical connector tube assembly as in claim 7, wherein the connector element comprises a pair of connector elements, and the tube ends each have an overmolded end element fixedly secured in a receiving cavity of the connector elements, respectively.

9. The high pressure medical connector tubing assembly of claim 7, wherein the tubing element comprises a braided tube formed of an inner braid encapsulated by a flexible polymer layer.

10. A method of forming a high pressure medical connector tubing assembly, the method comprising:

providing a pipe element including opposite pipe ends and a passageway therethrough;

overmolding a tip element onto at least one of the opposing tube ends, the tip element including an annular end portion having a preselected axial length, the annular end portion defining an inlet;

providing a connector element including a connector hub defining a receiving cavity, the connector element including a connector port defining a fluid passageway;

securing the tube end with the overmolded end element in the receiving cavity;

wherein the axial location of the radial stress concentration in the connector hub is preselected by shortening or lengthening the axial length of the annular end portion in the receiving cavity; and is

Wherein the inlet and the fluid passageway have a common inner diameter and are proximate to define a smooth transition seal between the fluid passageway and the inlet to maintain a laminar flow condition across the smooth transition seal.

11. The method of claim 10, wherein securing the tube end with the overmolded end element in the receiving cavity comprises solvent bonding.

12. The method of claim 10, wherein the end element is formed with at least one external indicator to visually identify the depth of insertion of the tube end with the overmolded end element into the receiving cavity.

13. The method of claim 10, wherein the tube element comprises a braided tube formed of an inner braid encapsulated by a flexible polymer layer.

14. The method of claim 10, wherein the inlet tapers from downstream of the smooth transition seal to the passageway in the pipe element.

15. The method of claim 14, wherein the inlet tapers at an angle of approximately between 0 ° and 80 °.

16. The method of claim 10, further comprising overmolding an end element onto each of the tube ends of the tube element.

17. The method of claim 16, wherein the tube ends each have an overmolded end element fixedly secured in the receiving cavities of the connector elements, respectively.

18. The method of claim 16, wherein the tube element comprises a braided tube formed of an inner braid encapsulated by a flexible polymer layer.