Patent Application
20080171983
1. Field of Invention
This invention relates to healthcare and veterinary care, specifically to needles.
2. Description of Prior Art
Needle breakage remains a problem in healthcare and veterinary care. Although greatly reduced by the advent of disposable needles, needle breakages still occur, and generally result in a minor surgical procedure being required to extricate the needle fragment.
Needles tend to break near the hub. Most often, they break because the needle is bent during use, both intentionally and unintentionally. The problem with broken needles occurs when the needle is inserted fully and the hub is pushing against the tissues. When a fully inserted needle breaks off, the tissues tend to close over the insertion point hole as the hub is withdrawn, thereby covering the needle fragment. Non-surgical attempts to retrieve the fragment generally result in pushing it deeper into the tissues .
To accomplish surgical recovery of the needle fragment, the patient must be informed, and anesthetized. In humans, broken needle incidents tend to result in litigation. In animals, anesthesia and surgery is costly, or worse, sometimes the broken needles are simply left in the animal, which causes a detection problem for the meat industry.
Most broken needle incidents could be prevented by avoiding full insertion of the needle to the hub. Needle lengths selected by manufacturers typically includes several millimeters of additional length beyond the usual anticipated depth of needle penetration. The additional length is provided to reduce the need to insert needles to the hub. However, in many cases, practitioners find that allowing the hub to stop the needle insertion is more efficient. In some cases, full insertion of the needle is also more effective.
Avoiding needle bends could also reduce needle breakage, but, again, practitioners often find that bending a needle can increase effectiveness, especially when working in a restricted space.
A few safety syringes include a needle depth restrictor that is attached to the syringe barrel, and may be extended down from the barrel to prevent needle insertion to the hub. The depth restrictors tend to be large. Typically the width is similar to the barrel. The large size of the restrictors can cause interference with routine use, especially when used in limited access sites. In some types, the user has the option to disable the depth restrictor, or the option not to engage it. In addition, the restrictor may limit how the needle can be bent, and thereby interferes with efficient and effective access of needle use.
The above needle depth restrictors suffer from a number of disadvantages:
A device similar to my needle hub assembly with novel tissue deflector has not been considered by many medical inventors because most do not know that needle breakage remains a significant problem. The few inventors who are aware of the problem are largely disinterested in depth restrictors due to their lack of popularity.
Accordingly, several objects and advantages of my needle hub assembly with a novel tissue deflector are:
Further objects and advantages are to provide a needle hub assembly that does not alter user technique, and does not distract the user, in order to prevent needle breakage.
Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
In the drawings, closely related figures have the same number, but different alphabetic suffixes.
The invention provides an improved needle hub assembly, a typical embodiment of which is shown in
It is preferred that deflector 10 permits a bend to be formed along the length of needle 12, said bend being located between hub 14 and at least a portion of deflector 10.
It is preferred that at least a portion of deflector 10 is flexible, so as to permit bending of needle 12 adjacent to hub 14. However, deflector 10 may be substantially non-flexible, such that deflector 10 fractures to permit needle bending adjacent to hub 14, or such that deflector 10 inhibits needle bending.
It is preferred that deflector 10 is non-uniform in diameter over the length of deflector 10, such that the diameter of deflector 10 is sufficiently wide at the end distal from hub 14 to deflect the tissues away from hub 14, and that the diameter of deflector 10 is minimized at the end proximal to hub 14 to be flexible and facilitate bending of needle 12 at that location. However, the diameter of deflector 10 may be uniform.
It is preferred that deflector 10 is comprised of a material that is identical to the material of which hub 14 is comprised, such as plastic, metal, and so on. It is preferred that deflector 10 comprises an extension of hub 14 over needle 12. However, deflector 10 material may be comprised of a material that is different than hub 14 material. Other materials which may comprise deflector 10 include solder, glue, ceramic, a widened portion of needle 12, a very thick layer of paint, and so on.
It is preferred that deflector 10 extend along needle 12 in the range of 2-10 mm from hub 14, with an extension of about 5 mm considered ideal.
Also shown are a multiplicity of rings, ring 22, spaced at intervals along deflector 10, wherein rings 22 have a greater diameter than the remainder of deflector 10, such that rings 22 further facilitate the tissue deflection function of deflector 10.
Additional embodiments of deflector 10 are shown in
It is preferred that connector 24 has a specified orientation relative to the bevel of needle 12, to facilitate bending of needle 12, so that connector 24 functions as indicator 18.
It is preferred that connector 24 is sufficiently flexible to permit a bend to be formed along the length of needle 12, said bend being located between hub 14 and at least a portion of deflector 10. However, connector 24 may be inflexible so as to prevent bending needle 12 proximal to hub 14, or connector 24 may fracture to permit bending needle 12 proximal to hub 14.
From the description above, a number of advantages of the needle hub assembly with deflector become evident:
By using the needle hub assembly of the invention, it is now possible, surprisingly, to retrieve a separated needle despite full insertion up to deflector 10.
The needle hub assembly offers the advantage that the user can now give injections or withdraw samples without burdensome needle-breakage precautions, and with confidence that a separated needle would be retrievable.
User selects a needle hub assembly having a flexible deflector 10 which is connected directly to hub 14, as shown in
User forcefully inserts the full distal portion of needle 12 into the tissues until stop 16 portion of deflector 10 pushes against the tissues, thereby displacing the tissues away from the advancing hub 14 until the insertion of needle 12 is halted. Deflector 10 protrudes from the tissues, and the proximal portion of needle 12 and hub 14 are held away from the insertion point of the distal portion of needle 12 into the tissues.
By chance, needle 12 separates adjacent to hub 14 at the location of the bend. Deflector 10 remains connected to the portion of needle 12 that is distal from the point of separation. Deflector 10 also remains connected to hub 14.
When user withdraws hub 14 away from the tissues, deflector 10 withdraws connected needle 12 entirely from the tissues. User may not even become aware that needle 12 has separated from hub 14.
User selects a standard needle hub assembly having no deflector 10. User selects a separate sleeve-shaped deflector 10 having a central lumen for receiving a needle. User inserts needle 12 into the lumen of deflector 10, and slides deflector 10 along needle 12 until it is in close proximity to hub 14, as shown in
User forcefully inserts the full distal portion of needle 12 into the tissues until stop 16 portion of deflector 10 pushes against the tissues, thereby displacing the tissues away from the advancing hub 14 until the insertion of needle 12 is halted. Deflector 10 protrudes from the tissues, and the proximal portion of needle 12 and hub 14 are held away from the insertion point of the distal portion of needle 12 into the tissues.
By chance, needle 12 separates from hub 14 proximally to hub 14. Deflector 10 remains connected to needle 12 distal from the point of separation.
When user withdraws hub 14 away from the tissues, hub 14 separates from deflector 10 and broken needle 12, but deflector 10 remains connected to needle 12. As the pressure exerted on the tissues by hub 14 is withdrawn, the tissues rebound, and push against deflector 10, and thereby move deflector 10 with still-connected needle 12 outward a few millimeters until the tissues are completely rebounded. Deflector 10 and a portion of needle 12 protrude above the surface of the tissues. After user becomes aware that needle 12 has separated from hub 14, user grasps deflector 10 and withdraws deflector 10 with connected needle 12 from the tissues.
User connects a needle hub assembly having a deflector 10 which is not connected to hub 14, as shown in
User forcefully inserts the full distal portion of needle 12 into the tissues until deflector 10 pushes against the tissues, thereby displacing the tissues away from the advancing hub 14 until the insertion of needle 12 is halted. Deflector 10 protrudes from the tissues, and the proximal portion of needle 12 and hub 14 are held away from the insertion point of the distal portion of needle 12 into the tissues.
By chance, needle 12 separates from hub 14 proximally to hub 14. Deflector 10 remains connected to needle 12 distal from the point of separation.
When user withdraws hub 14 away from the tissues, hub 14 separates from deflector 10 and broken needle 12, but deflector 10 remains connected to needle 12. As the pressure exerted on the tissues by hub 14 is withdrawn, the tissues rebound, and push against deflector 10, and thereby move deflector 10 with still-connected needle 12 outward a few millimeters until the tissues are completely rebounded. Deflector 10 and a portion of needle 12 protrude above the surface of the tissues. After user becomes aware that needle 12 has separated from hub 14, user grasps deflector 10 and withdraws deflector 10 with connected needle 12 from the tissues.
User connects a needle hub assembly having a connector 24 connected to hub 14, as shown in
User forcefully inserts the full distal portion of needle 12 into the tissues until stop 16 portion of deflector 10 pushes against the tissues, thereby displacing the tissues away from the advancing hub 14 until the insertion of needle 12 is halted. Deflector 10 protrudes from the tissues, and the proximal portion of needle 12 and hub 14 are held away from the insertion point of the distal portion of needle 12 into the tissues.
By chance, needle 12 separates from hub 14 proximally to hub 14. Deflector 10 remains connected to needle 12 distal from the point of separation.
When user withdraws hub 14 away from the tissues, hub 14 separates from deflector 10 and broken needle 12, but deflector 10 remains connected to needle 12. As the pressure exerted on the tissues by hub 14 is withdrawn, the tissues rebound, and push against deflector 10, and thereby move deflector 10 with still-connected needle 12 outward a few millimeters until the tissues are completely rebounded. Deflector 10 and a portion of needle 12 protrude above the surface of the tissues. After user becomes aware that needle 12 has separated from hub 14, user grasps deflector 10 and withdraws deflector 10 with connected needle 12 from the tissues.
Accordingly, the reader will see that the needle hub assembly of this invention could prevent the complications from most broken-needle incidents. The deflector can facilitate retrieving most separated needles by initially preventing insertion of the entire needle length, and secondarily, by maintaining a connection to the fractured needle fragment. Furthermore, the needle hub assembly has the additional advantages in that it facilitates retrievability of separated needles very economically.
The presence of deflector 10 with a needle hub assembly should not necessitate manufacturing needles 12 with increased length to accommodate deflector 10. Manufacturers typically provide an additional length of several millimeters beyond the usual depth of needle penetration. Deflector 10 would connect to needle 12 substantially within that additional length all ready provided for most needles.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention and process, but as merely providing illustrations of some of the presently preferred embodiments of this invention.
For example, deflector 10 may be comprised of a portion of a needle cap or sheath, such that a deflector 10 portion of the needle cap remains connected to needle 12 after the remaining portion of the needle cap is removed from needle 12 prior to use.
For another example, hub 14 may be continuous and integral with a syringe, so that needle 12 is connected directly to a hub area of a syringe, rather than to a separate hub 14.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
