Safety Hypodermic Needle

Abstract

A hypodermic needle for safely injecting fluid into nerve and vessel crowded areas of a patient. The needle comprises a pointed hollow piercing member slidably mounted in a substantially frictionless manner about a hollow fluid delivery tube. The delivery tube has a blunt nose and is longitudinally of a constant diameter, has at least one fluid opening near its blunt end, and is adapted to be connected to a conventional syringe at its other end. The hollow piercing member is connected to the delivery tube by a finger-operated collapsible bar. The bar is provided with a centrally located groove to facilitate collapse at the moment the operator removes the force of his finger. The blunt nose delivery tube is then free to penetrate into the tissue of the patient without endangering nerve or vessel.

Description

BACKGROUND OF THE INVENTION

The use of hypodermic injections is wide spread and by no means a recent development. But notwithstanding the age of this art, there still exist numerous drawbacks. The common hypodermic needle takes the form of a slender tubular member having a sharp tip for piercing the skin and tissue of the patient. And one very serious drawback of this commonly used needle is that when the needle cuts through the tissue, there is the danger that damage may result by entering blood vessels or puncturing nerves.

One important improvement to the conventional needle has recently been developed. And this improvement is the subject of U.S. Pat. No. 3,530,492 disclosing an apparatus for administering a hypodermic injection. With such apparatus, the skin of the patient is punctured with a small sharp pointed piercing member. Then a long blunt end delivery tube frictionally associated with the piercing member, moves through the tissue of the patient when the frictional forces between the piercing member and delivery tube are overcome.

In this recently developed needle, the delivery tube has an outside diameter in the region of the blunt end portion which is slightly larger than the diameter of the remainder of its shank portion. This is necessitated by the requirement that the piercing member frictionally engage the blunt end portion of the delivery tube. In operation, the piercing member is inserted into the patient until a limiting collar abuts the patient's skin. Then, upon the application of additional force, the frictional engagement between the piercing member and delivery tube is released, and the delivery tube is free to slide into the tissue of the patient.

The drawback of this needle is a result of the necessary friction engagement between the piercing member and delivery tube. For at the moment the frictional force between the piercing member and the delivery tube has been overcome, with the operator still applying pressure on the syringe, the delivery tube thrusts forward into the tissue of the patient. The operator has no positive control over the pressure needed for overcoming the frictional engagement, and hence it is possible that an excessive pressure can be applied to the needle. Then, even notwithstanding the blunt end of the delivery tube, there could still result serious damage to tissue, blood vessels, nerves and even bone.

Further, another disadvantage with this prior art hypodermic needle is that the necessary shape of the delivery tube requires a mechanically difficult manufacturing technique. The delivery tube of U.S. Pat. No. 3,530,492 requires the manufacture of an enlarged blunt end integral with a reduced diameter shank portion.

It is toward the elimination of these drawbacks of the prior art that the present invention is directed.

SUMMARY OF THE INVENTION

The present invention relates to an apparatus and method for safely injecting fluid into a patient. The skin surface of the patient is punctured with a sharp piercing member, and injection depth is accomplished by the insertion of a blunt end delivery tube having at least one opening in the region of its blunt end. The operator has positive control over the inventive hypodermic needle at all times, and can release the delivery tube for smooth penetration into the tissue of the patient at will.

The hypodermic injection apparatus of the present invention includes a sharp, preferably metallic, pointed member for piercing the skin of the patient. A collar is mounted on the end of the piercing member, remote from the sharp end, and serves to limit penetration into the patient's tissue. An elongated delivery tube defines a coaxial frictionless mount for the piercing member, and serves to deliver fluids to the patient. The delivery tube is of the same diameter over its entire length, and has, at its blunt end, at least one opening at its surface. At its other end, there is provided an integral hub to facilitate mounting on a conventional syringe.

As the elongated delivery tube of the present invention is of a constant diameter over its entire length, manufacturing costs are substantially lower than those involved in manufacturing needles according to the referenced prior art.

In the apparatus of the present invention, the sharp pointed piercing member is connected with the hub of the delivery tube through a preferably plastic finger-operated collapsible bar. This bar is at one end integrally secured to the collar of the piercing member, and at the other end similarly secured to the hub of the delivery tube. At the center of the bar is a groove to facilitate the collapse of the finger-operated bar when released by the operator.

As the combination of the hub, bar and collar are conveniently molded in one piece plastic, the inventive apparatus can be manufactured easily and at low cost. This permits economical disposal of the unit after one use.

Due to the fact that the sharp pointed piercing member is slidably mounted about the elongated delivery tube is a substantially frictionless manner the operator maintains full control over the unit. The release of the delivery tube from the piercing member is accomplished at the will of the operator and requires the exertion of no special forces by the operator. Hence, the operator can carefully and accurately perform the injection procedure, thus minimizing the risk of injury to soft tissue, blood vessels, nerves and bone.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross section showing the manner in which the inventive hypodermic needle is inserted into the skin of a patient; and

FIG. 2 shows the inventive hypodermic needle inserted deep into the tissue of the patient.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference first to FIGS. 1 and 2, the basic construction of the inventive hypodermic needle will be described. The inventive needle unit is shown generally at 10, and comprises a sharp pointed piercing member 12 mounted on a hollow elongated delivery tube 14. The front end of the piercing member 12 is provided with a sharp point 16, and the rear end is provided with a limiting collar 18. The piercing member 12 is slidably mounted on the elongated delivery tube 14, in a substantially frictionless manner.

The elongated delivery tube 14 is of a uniform diameter over its entire length, has a blunt nose 20, and has at least one opening 22 in its surface. At its end remote from the blunt nose 20, the delivery tube 14 is provided with a firmly mounted hub 22, adapted to associate with a conventional hypodermic syringe 24. And as can best be seen in FIG. 1, the hub 22 is internally threaded so as to mate with the externally threaded nose of the syringe 24.

In FIGS. 1 and 2, it is shown that the collar 18 and the hub 22 are made integral through the means of a collapsible bar 26. At the center of bar 26 is a groove 28 separating the bar into front and rear elements 30 and 32 respectively.

As indicated in the figures, the hub 22, the collapsible bar 26 and the collar 18 of the piercing member are integral and of a plastic material. The piercing element of member 12 is metallic and is fixed in the collar 18. The delivery tube 14 is also shown to be metallic, and is similarly force fit into hub 22.

The operation of the inventive hypodermic needle will now be described. Initially, the member 12 is injected into the skin 34 of the patient until further penetration is prevented by the collar 18. The finger 36 of the operator exerts a continuous but slight force on the bar 26 and in the direction of arrow 38, until the collar 18 abuts the skin surface 34. When collar 18 abuts the skin surface 34, the operator removes his finger, thereby releasing the collapsible bar 26, but continues to exert force on the syringe 24 in the direction of arrow 40. Then the collapsible bar 26 folds, as shown in FIG. 2, and the delivery tube 14 is slowly and accurately moved through the tissue of the patient. Finally, the fluid housed in the syringe is injected into the patient through the openings 22.

As is shown in the figures, there are a plurality of openings 22 provided along the length of hollow delivery tube 14. In this manner, a relatively uniform dispersion of fluid can be ensured. Also, the figures illustrate an integral molded plastic unit comprising hub 22, bar 26 and collar 18. It should be understood, however, that such specific descriptions are provided for illustrative purposes only. It is the intention that the invention be interpreted in its broadest sense, as relating to an apparatus and a method for safely administering an injection with positive control by the operator and hence without danger to the integrity of vessels, nerves and bone, and be limited only as defined in the appended claims.

Claims

What is claimed is:

1. An apparatus for associating with a syringe and for safely administering a hypodermic injection to a patient, the apparatus comprising: an elongated hollow delivery tube having a substantially uniform diameter over a major portion of its length and being substantially rigid; a blunt nose at one end of said delivery tube; at least one opening in said delivery tube for delivering the injection to a patient; mounting means at the end of the delivery tube remote from said blunt nose for associating with a syringe; a sharp pointed piercing member slidably mounted on said elongated delivery tube in a substantially frictionless manner; substantially rigid control means for maintaining said piercing member over said blunt nose while said sharp pointed piercing member is inserted into the tissue of a patient and while a force is applied thereto by the operator administering the hypodermic injection; and means for disabling said substantially rigid control means upon removal of said force for allowing said piercing member to slide along the length of said delivery tube in the direction of said mounting means after said sharp pointed piercing member has been inserted in said tissue.

2. The apparatus recited in claim 1, and further comprising: limiting means for controlling the depth of penetration of said piercing member into the tissue of the patient.

3. The apparatus recited in claim 2, wherein said limiting means takes the form of a collar fixedly associating with said piercing member at a predetermined spacing from the point thereof.

4. The apparatus recited in claim 3, wherein said piercing member is metallic, wherein said collar is plastic, and wherein said piercing member is fixed in said collar.

5. The apparatus recited in claim 1, wherein said control means acts between said piercing member and said delivery tube.

6. The apparatus recited in claim 5, wherein said control means takes the form of a collapsible bar connected at one end to the piercing member and at the other end to the region of the delivery tube remote from said blunt nose.

7. The apparatus recited in claim 6, wherein the end of said collapsible bar remote from the blunt nose of the delivery tube is connected to said mounting means.

8. The apparatus recited in claim 6, wherein said collapsible bar comprises: a front element; a rear element; and an area of reduced cross section intermediate said front element and said rear element.

9. The apparatus recited in claim 8, and further comprising: collar means fixedly associating with said piercing member for limiting the penetration thereof into the tissue of the patient; wherein said front element is connected to said mounting means.

10. The apparatus recited in claim 9, wherein said collar means, said collapsible bar and said mounting means are integral and of a plastic material.

11. The apparatus recited in claim 10, wherein said integral combination of elements are of molded plastic.

12. The apparatus recited in claim 6, wherein said collapsible bar is controlled by the finger of the operator administering the hypodermic injection.

13. A method for safely administering a hypodermic injection to a patient comprising the steps of: using an apparatus comprising a substantially rigid hollow blunt nose delivery tube over which a sharp pointed piercing member is slidably mounted in a substantially frictionless manner and further comprising substantially rigid control means for maintaining the piercing over the blunt nose while the piercing member is inserted into the tissue of the patient and while a force is applied thereto by the operator administering the hypodermic injection, and means for disabling the substantially rigid control means upon removal of such force; inserting the sharp pointed piercing member a limited depth into the tissue of the patient; maintaining the piercing member over the blunt nose of the delivery tube during the insertion of the piercing member into the skin and tissue of the patient by applying a force to the substantially rigid control means; freeing the relative association of the piercing member and the delivery tube by removing said force from the substantially rigid control means thereby disabling said control means by way of the action of said means for disabling the control means, thereby allowing the piercing member to slide along the delivery tube in a direction away from the blunt nose; and delivering the injection into the patient through at least one aperture in the delivery tube.

14. The method recited in claim 13 wherein the depth of penetration of the piercing member into the tissue of the patient is limited by means of a collar fixedly associated with the piercing member at a predetermined spacing from the point thereof.

15. The method recited in claim 14, wherein the piercing member is maintained over the blunt nose through the means of a collapsible bar connected at one end to the piercing member and at the other end to the region of the delivery tube remote from the blunt nose.

16. The method recited in claim 15, wherein the collapsible bar comprises a front element, a rear element, and an area of reduced cross section intermediate the front element and the rear element.

17. The method recited in claim 15, wherein the position of the collapsible bar and hence the spacing between the piercing member and the blunt nose of the delivery tube is controlled by the finger of the operator administering the hypodermic injection.