Needle-based medical device including needle guide

A needle-based medical device including a needle guide and a method for constructing the same are disclosed. The needle-based medical device includes a tube having a first lumen; a needle guide which is dimensioned to be inserted into the lumen of the tube, and a needle. The needle is inserted such that an end is positioned in the needle guide. A glue may also be provided to secure the needle guide to the tube. In one embodiment, the tube may be made of extruded plastic.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This patent application relates to medical devices that utilize a needle secured to a hub, including but not limited to catheter assemblies, blood collection devices, huber needle assemblies, syringes, and other needle-based medical devices.

2. Related Art

Current medical devices that include needles are formed by the use of molded tubes, a needle, and a rigid hub to which the needle is secured. The needle hub may be made out of a thin extruded tube or a thin molded tube. Devices of this type are shown in U.S. Provisional Patent Application Nos. 60/659,213, 60/659,217, 60/659,226, and 60/714,954, which are incorporated by reference herein. This method of assembling needle-based medical devices presents several problems associated with the use of molded tubes. One problem is the sheer expense of molding each individual tube used to form a device. The actual manufacture of such devices is also problematic. Molding long, thin members for medical devices with molded tubes is difficult, particularly where the mold core pin must be supported at its distal end. Particularly in small gauge needles, the core pin must have an extremely small diameter, rendering it extremely fragile, difficult to support, and difficult to center. Additionally, each needle size requires a different size core pin to form the needle. In view of the foregoing, there exists a need in the art to overcome one or more of the deficiencies indicated herein.

SUMMARY OF THE INVENTION

A needle-based medical device including a needle guide and a method for constructing the same are disclosed. The needle-based medical device includes a tube having a first lumen; a needle guide which is dimensioned to be inserted into the lumen of the tube, and a needle. The needle is inserted such that an end is positioned in the needle guide. A glue may also be provided to secure the needle guide to the tube. In one embodiment, the tube may be made of extruded plastic.

According to a first aspect of the invention, a needle-based medical device is provided, the medical device comprising: a tube having a first lumen; a needle guide dimensioned to be inserted at least partially into the first lumen, the needle guide including a second lumen and a glue well; a needle having an end in the second lumen; and glue to secure the needle guide to the tube.

According to a second aspect of the invention, a method of constructing a needle-based medical device is provided, the method comprising: providing a tube having a first lumen; providing a needle guide; inserting the needle guide into the first lumen; inserting a needle into the needle guide; introducing glue into a glue well between the needle guide and the first lumen; and curing the glue.

According to a third aspect of the invention, a needle guide for a needle-based medical device is provided, the needle guide comprising: a body for insertion into a first lumen of a tube, the body including a second lumen to position an end of a needle.

According to a fourth aspect of the invention, a needle hub for a needle-based medical device is provided, the needle hub comprising: a tube having a first lumen; a needle guide having an outer surface for engaging the inner surface and a second lumen for positioning a needle; and a glue for hermetically sealing the needle, the tube, and the needle guide.

DETAILED DESCRIPTION

A device and a method are disclosed that provide an improved method of producing needle-based medical devices more effectively and efficiently.

Referring now toFIG. 1, one embodiment of a needle-based medical device10is shown in the form of, for example, a catheter introducer10with a needle shield12, including components made from concentric extruded tubes12,14, and18. These concentric tubes include needle shield12, outer housing14, and needle hub18. The use of extrusions substantially reduces the cost of such devices compared with existing devices made out of molded parts, although molded tubes may be used. Although medical device10is described herein as a catheter introducer assembly, it is understood that the teachings of the invention are applicable to any type of needle-based device, including but not limited to catheter introducers, blood collection devices, huber needle assemblies, and syringes.

Referring now toFIG. 2, tube30, needle guide20, and needle16are shown in an exploded view. Needle16has a distal end26and a proximal end28, and is secured to needle guide20. Needle guide20is secured to tube30, forming the needle and hub for a needle-based medical device10(FIG. 1). Body22of needle guide20is inserted into distal end38of tube30. Proximal end28of needle16is inserted into body22of needle guide20. Tube30may be, for example, a plastic extrusion made of polypropylene, acrylic, or other similar material, and has a proximal end36, a distal end38, and a first lumen32extending between proximal end36and distal end38.

Referring now toFIG. 3, a more detailed view of needle guide20is provided. In one embodiment, needle guide20includes a body22for insertion into first lumen32(FIG. 2) of tube30(FIG. 2). Body22may include a second lumen40to position an end28(FIG. 2) of needle16. In one embodiment, body22is generally cylindrical and further includes an outer surface42. Body22is joined to distal end24by at least one rib46which extends from body22. In one embodiment, the number of ribs may be three, and each of three ribs46may be positioned approximately 120 degrees from each other rib46. It is understood, however, that any number of ribs greater than one may be used. As will be described herein, empty spaces48lie between ribs46, in a configuration which forms a glue well50adjacent to the at least one rib46and first lumen32(FIG. 2), and includes a space between proximal end28of needle16and second lumen40.

Referring now toFIG. 4, a first embodiment of an assembled needle hub is depicted, including tube30having first lumen32, needle guide20dimensioned to be inserted at least partially into first lumen32. Needle16has proximal end28in second lumen40, and a glue56is positioned to secure needle guide20to tube30. Proximal end28of needle16is inserted into second lumen40in needle guide20, the second lumen having a diameter slightly larger than that of needle16. In one embodiment, a friction fit is provided between second lumen40and proximal end28of needle16, maintaining substantially circumferential contact between the second lumen40and the needle16.

Body22of needle guide20is inserted into first lumen32such that it is positioned coaxially with tube30. Needle guide20may include a flange44coupled to at least one rib46at a distal end of needle guide20, which is positioned to engage with outer wall34of tube30when body22is inserted into first lumen32. Flange44thus acts as a mechanical stop, limiting the depth to which body22can be inserted into first lumen32. The ribs46have a diameter just smaller than the diameter of first lumen32, which provides a mechanical fit between body22and first lumen32.

When body22is inserted into first lumen32, first annular space52is formed between the inner wall of tube30and outer surface42of body22. This space ideally measures about 0.001-0.005 inch, which allows glue56to flow via capillary action into first annular space52after it is deposited in glue well50. A very tight fit of ribs46is not preferred because that may cause distortion of distal end38of tube30. In one embodiment, a second annular space54is formed between second lumen40and the outer surface of proximal end28of needle16. In this embodiment, annular space54is also filled with glue as part of glue well50by capillary action; however, second annular space54is not essential to the practice of the claimed invention.

Referring now toFIG. 5, a second embodiment of the assembled needle hub is depicted. According to this embodiment, needle16can be pre-molded into needle guide20and then inserted into first lumen32. The inner surface of tube20may include a depth stop to limit axial movement of the needle guide relative to the tube. The depth stop may be an abutment57positioned on the inner surface of tube30. Returning toFIG. 1, once needle hub18has been assembled, it can be used in a device such as the catheter inserter or any similar needle-based device. Needle hub18may also be assembled during assembly of such devices.

A first embodiment of a method of constructing a needle-based medical device is provided wherein the device is assembled as follows. Tube30having first lumen32is provided along with needle guide20. Needle guide20, e.g., body22of needle guide20, is inserted into first lumen32until flange44abuts outer wall34of tube30, preventing further insertion. Proximal end28of needle16is then inserted into second lumen40from distal end24of guide20. Glue56is introduced into glue well50, and then flows by capillary action into first annular space52between outer surface42of body22of guide20and inner wall of tube30. In an embodiment including second annular space54, glue56is also allowed to flow into second annular space54between needle16and body22of guide20. Glue56is then cured.

A second embodiment of a method of constructing a needle-based medical device is provided wherein the proximal end28of needle16is inserted into second lumen40from distal end24of needle guide20before body22is inserted into first lumen32. In that case, the coefficient of friction between needle16and guide20must be greater than the coefficient of friction between guide20and tube30. In an alternative embodiment, a press fit or serrations in needle guide20may be provided to hold needle guide20in place against the force of insertion of needle16.

Referring now toFIG. 6, a first embodiment of accessing glue well50during manufacture is provided. According to this embodiment, needle shield12may be threaded onto needle16from proximal end28(the blunt end) of needle16. In that case, access to glue well50may be obtained via a cutout62in needle shield12. Glue nozzle64is inserted into cutout62and introduces glue56into glue well50.

Referring now toFIG. 7, a second embodiment for accessing glue well50during manufacture is depicted. According to this embodiment, access to glue well50is provided while keeping distal end58of needle shield12separate from needle shield body60(but still threaded on needle16) during the gluing process. In that case, glue nozzle64is inserted into the end of lumen66of needle shield body60. Glue56is introduced into glue well50, after which, distal end58of needle shield12is snapped and bonded or otherwise attached to needle shield body60.