TECHNICAL FIELD

The disclosure relates generally to a multi-point beveled cannula and a multipoint beveled cannula-hub assembly for applying a substance beneath a layer of skin or tissue. The multi-point beveled needle punctures the surface and penetrates to a desired depth into the skin or tissue at a targeted location and delivers a precise, well- defined mark.

BACKGROUND

In medical procedures such as surgery or radiation therapy, markings, also referred to as tattoos, are usually applied to the skin of a patient to create reference points. Marking devices using felt-tip nibs are not capable of applying a marking agent under the surface layer of skin. Medical skin marking devices having a rupturable cartridge containing a marking agent within a housing use a standard, general-purpose needle. Standard hypodermic needles are very sharp with long bevels for intramuscular injection. Such standard needles leave an amorphous,

indistinguishable shape and, thus, are unsuited for accurate, cutaneous application of a marking agent in the creation of a precise reference point necessary, for example, for repeated positioning of external beam radiation therapy (EBRT).

Other procedures such as allergy testing, smallpox immunization and tuberculosis testing require epicutaneous or intracutaneous puncture of the skin to apply substances such as a biological material or drug. In allergy immunotherapy, common skin test techniques include "skin prick" and "skin injection" tests. A skin prick test, also called a puncture or scratch test, checks for immediate allergic reactions to as many as forty different substances at once. This test is usually done to identify allergies to pollen, mold, pet dander, dust mites, and foods. In adults, the test is usually done on the forearm. Children may be tested on the upper back. This type of testing uses needle (lancets) that barely penetrate the surface of the skin. The skin injection test uses a needle to inject a small amount of allergen intradermally into the skin on the arm. In both cases, the devices used are imprecise and the results are inconsistent.

There is a need for a cannula that penetrates the skin to a specific depth and produces a discernable, precise point of reference and a cannula assembly that is attachable to a substance-containing device.

SUMMARY

The disclosure provides a multi-point cannula having a lumen, a proximal end and a distal end, the distal end having two or more beveled surfaces, each beveled surface having two peaks or points, a valley or heel, wherein the cannula penetrates an outer layer of skin to a specific depth.

In one aspect, depth of skin penetration of the cannula is based on the distance of the bevel peak or tip to the valley or heel.

In certain embodiments, the cannula penetrates the epicutaneous layer, the intracutaneous layer or the subcutaneous layer of skin.

In one aspect, the multi-point cannula comprises four points.

In certain embodiments, the grind angle of the bevel is 9 degrees plus or minus 2 degrees, 12.5 degrees plus or minus 2 degrees, 20 degrees plus or minus 2 degrees, 25 degrees plus or minus 2 degrees, up to and including 45 degrees.

In another aspect, the multi-point cannula further comprises a hub base, which may or may not incorporate a luer lock or other locking mechanism.

In one aspect the proximal end of the cannula or the cannula hub base is attachable to a container containing a substance. In certain embodiments, the substance is a marking agent, an allergen, a biologic, contrast media, an

immunotherapeutic substance, a vaccine or a drug. In one aspect, the container comprises a flexible housing comprising a rupturable cartridge containing a marking agent. In one aspect, the proximal end of the multi-point beveled cannula is configured to pierce a stopper or membrane of a container containing a substance, wherein the substance flows into the lumen of the cannula.

In another aspect, the multi-point beveled cannula is dipped into a substance and the substance is applied to a target.

The recitation herein of desirable objects which are met by various embodiments of the present disclosure is not meant to imply or suggest that any or all of these objects are present as essential features, either individually or collectively, in the most general embodiment of the present disclosure or in any of its more specific embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 A-1B: FIG. 1 A shows a multi-beveled needle-hub assembly; FIG. IB shows the needle-hub assembly with a protective guard covering the needle tip.

FIGS. 2A-C: FIG. 2A and its exploded view (DETAIL A) show a quad bevel tip grind cannula with a grind angle 23 (DIM "A"); FIG. 2B depicts the cannula gauge size, in this case (DETAIL B) 20 gauge regular wall cannula; FIG. 2C and its exploded view (DETAIL C) show a perspective view of quad bevel tip grind needle.

FIGS. 3 A-I are side views of needles of various gauges and grind angles: FIGS. 3A-C show 18G, regular wall (RW) needles with grind angles of 9°, 12.5° and 20°, respectively; FIGS. 3D-F show 20GRW needles with grind angles of 9°, 12.5°, and 25°, respectively; FIGS. 3H-I show 22GRW needles with grind angles of 9°, 12.5° and 20°, respectively.

FIG. 4 shows a skin marking comparison test using a 22G x 12.5° quad-grind needle (1-6), a 18G hypodermic needle (7-12), and a 22G hypodermic needle (13-18) DETAILED DESCRIPTION

Disclosed herein are a multi-point cannula 1 and a multi-point cannula-hub assembly 10 for applying a substance to the tissue of a patient. As shown in FIGS. 1 A and IB, the sharpened multi-point cannula (needle) 1 may be attached to a hub 2, for example, a LUER-LOK hub, to form a multi-point cannula-hub assembly 10. The length of the cannula, L, can be of various sizes. In one embodiment, the needle length is approximately 1.00 inches, for example 0.95 to 1.05 inches or 0.97 to 1.03 inches. FIG. IB shows a complete assembly with a shield or cover 3. The cover 3 can be a translucent or transparent plastic.

The cannula 1 or hub 2 can be attached to a container. Containers can include but are not limited to marking devices or syringes. The container may comprise a flexible housing comprising a rupturable cartridge containing a substance.

Substances which may be applied using the cannula include, but are not limited to a marking agent, an allergen, biologies, contrast media, an

immunotherapeutic substance, a vaccine or a drug.

The hub 2 may be mated with a coupler, for example, on a syringe or a skin marking device. The needle can be in a range of needle gauges including but not limited to 18G, 20G, 22G, and 25G. The hub base 2 can be in a range of sizes.

The multi-beveled needle can be made by methods known in the art. However, the angle of grind and height of the bevel can affect the depth of puncture.

In one embodiment, shown in FIG. 2A, the multi-point cannula 1 has a lumen 25 which traverses the length of the cannula 1, a distal end 21 and a proximal end 22. The distal end 21 of the multi -point cannula 1 has bevels 31. Each bevel 31 has a bevel peak 32, bevel heel 33, bevel base 34, and grind angle 23. The grind angle 23 can be in the range of 5-45 degrees, for example, 9 degrees plus or minus 2 degrees, 12.5 degrees plus or minus 2 degrees, 20 degrees plus or minus 2 degrees, or 25 degrees plus or minus 2 degrees. FIG. 2A shows a quad-grind 20GRW needle having a grind angle 23 of 20 degrees with a tip to heel penetration depth of approximately 0.009 inches for epicutaneous or epidermal puncture.

FIG. 2B shows the inside diameter and outside diameter of, in this case, a 20 gauge regular wall cannula.

In one embodiment, the cannula is a thicker, Regular Wall or Heavy Wall cannula, rather than a thin walled or ultra thin walled cannula (commonly used in a biopsy needle), in order to provide for "tenting" of the skin by the heel bevel, thus creating the "stop" mechanism at each heel location between points allowing for consistent specific depth penetration.

FIG. 2C shows a quad-grind 20GRW needle having a grind angle 23 of 12.5 degrees with a peak 32 to heel 33 penetration depth of approximately 0.016 inches for intracutaneous or intradermal puncture. In one embodiment, the minimum and maximum tip height difference does not exceed .005 inches. In another embodiment, the distance from bevel heel 33 to bevel peak 32 is consistent with tip height. The bevel heel 33- can act as a "stop" to limit depth of puncture.

Penetration depth, size and shape of the puncture can be varied. Depth of penetration is affected by the distance between the bevel peak 32 and the bevel heel 33. The relativity of bevel peak 32 to the bevel heel 33 can be predetermined by virtue of varying the grind angle. Increasing the distance between opposing peaks or points (i.e., size) is accomplished by increasing the diameter of the cannula. Changing the shape of the puncture or mark can be done by changing the number of peaks or points. EXAMPLES

Penetration Depth:

FIG. 3 shows cannulae of 18GRW, 20GRW and 22GRW which were subjected to grinds of various angles. FIGS. 3A-C show 18G, regular wall (RW) needles with grind angles of 9°, 12.5° and 20°, respectively; FIGS. 3D-F show 20GRW needles with grind angles of 9°, 12.5°, and 25°, respectively; FIGS. 3H-I show 22GRW needles with grind angles of 9°, 12.5° and 20°, respectively.

Penetration depth (peak to heel) was measured. As shown in Table 1, the narrower the grind angle, the greater the peak to heel distance, resulting in deeper penetration.

Table 1

Gauge, Regular Wall Grind Angle (degrees) Distance (inches)

9.0 .0305

18 12.5 .0218

20.0 .0133

20 9.0 .0217

12.5 .0160

25.0 .0074

22 9.0 .0150

12.5 .0100

20.0 .0065 Shape Comparison Test:

Reference points, such as those used in EBRT, were made using a 22G x 12.5° quad-grind needle (1-6), a 18G hypodermic needle (7-12), and a 22G hypodermic needle (13-18). As shown in FIG. 4, the quad grind needle yielded a substantially round, well-defined dot while the standard 18G and 22G needles yielded amorphous indistinctive shapes. A 20GRW quad grind needle yielded a definitive dot of approximately 1mm size (not shown).

While the invention has been described in detail herein in accordance with certain preferred embodiments thereof, many modifications and changes therein may be effected by those skilled in the art. Accordingly, the foregoing disclosure should not be construed to be limited thereby but should be construed to include such aforementioned obvious variations and be limited only by the spirit and scope of the following claims.