Patent Description:
The present invention relates to a point geometry for a needle, and more particularly, to a five-beveled point geometry for a needle for reducing needle penetration force.

Needles are used in the medical field to obtain samples, such as blood, from patients. Such needles are formed from an elongate tube or cannula having a fluid-conducting lumen and a central axis. The proximal end of the needle is typically configured for mating to, or is otherwise affixed to, a fluid collection device such as a syringe assembly or a blood collection assembly. The distal end of the needle is provided with a pointed tip geometry for piercing a patient's skin or tissue so as to obtain a sample from the patient. A need exists for an improved needle which minimizes patient discomfort and achieves appropriate sample access.

A multi-bevelled needle according to the state of the art is disclosed in <CIT>.

When designing the pointed tip of the needle, numerous considerations must be taken into account. For instance, it is desirable to minimize the needle penetration force necessary for urging the pointed tip of the needle through the skin and flesh structure of the patient. This force is directly related to the resistance of the cannula point to moving through the skin and the underlying tissue. It is generally recognized that by reducing needle penetration force, the patient will experience less pain, making the sample collection more comfortable. Further, it is believed that the pain experienced by the patient during needle insertion is caused by the cutting of the tissue by the bevel edges at the cannula tip and subsequent stretching of the tissue by the cannula body. The more gradual the transition between the differing bevels of the tip, the smoother the cutting and stretching action of the cannula.

Another consideration in designing point geometry is to prevent or otherwise minimize tissue coring. Coring results when a portion of a material through which the needle has penetrated becomes lodged in the lumen adjacent the pointed tip.

In accordance with an embodiment of the present invention, a needle having a multi-beveled point includes a cannula having a lumen and a central axis defined therethrough, the multi-beveled point provided at one end of the cannula. The multi-beveled point includes a primary bevel, two middle bevels, and two tip bevels, wherein each of the middle bevels extends between the primary bevel and one of the tip bevels. The primary bevel is provided on the cannula at a first angle of inclination with respect to the central axis and a first angle of rotation with respect to the central axis, the two middle bevels are provided on the cannula at a second angle of inclination with respect to the central axis and a second angle of rotation with respect to the central axis, and the two tip bevels are provided on the cannula at a third angle of inclination with respect to the central axis and a third angle of rotation with respect to the central axis. The third angle of inclination is greater than the second angle of inclination and the second angle of inclination is greater than the first angle of inclination, and the second angle of rotation is equal to the third angle of rotation.

In certain embodiments, the first angle of inclination is between <NUM>° and <NUM>°. The first angle of inclination may be <NUM>°. In other embodiments, the second angle of inclination is between <NUM>° and <NUM>°, such as between <NUM>° and <NUM>°. The second angle of inclination may be <NUM>°. In other embodiments, the third angle of inclination is between <NUM>° and <NUM>°, such as between <NUM>° and <NUM>°. The third angle of inclination may be <NUM>°.

The first angle of rotation may be different from the second angle of rotation and the third angle of rotation. The first angle of rotation may be <NUM>°. The second angle of rotation and the third angle of rotation may be between <NUM>° and <NUM>°. Optionally, the second angle of rotation and the third angle of rotation may be between <NUM>° and <NUM>°, such as between <NUM>° and <NUM>°.

In accordance with another embodiment of the present invention, a syringe assembly includes a syringe barrel and a needle attached to the syringe barrel, the needle having a cannula having a lumen and a central axis defined therethrough. The needle includes a multi-beveled point provided at one end of the cannula. The multi-beveled point includes a primary bevel, two middle bevels, and two tip bevels, wherein each of the middle bevels extends between the primary bevel and one of the tip bevels. The primary bevel is provided on the cannula at a first angle of inclination with respect to the central axis and a first angle of rotation with respect to the central axis, the two middle bevels are provided on the cannula at a second angle of inclination with respect to the central axis and a second angle of rotation with respect to the central axis, and the two tip bevels are provided on the cannula at a third angle of inclination with respect to the central axis and a third angle of rotation with respect to the central axis. The third angle of inclination is greater than the second angle of inclination and the second angle of inclination is greater than the first angle of inclination. The second angle of rotation is equal to the third angle of rotation.

In certain embodiments, the first angle of inclination is between <NUM>° and <NUM>°. The second angle of inclination is between <NUM>° and <NUM>°. The third angle of inclination is <NUM>° and <NUM>°. In certain configurations, the first angle of rotation is different from the second angle of rotation and the third angle of rotation. The first angle of rotation may be <NUM>° and the second angle of rotation and the third angle of rotation may be between <NUM>° and <NUM>°.

In accordance with another embodiment of the present invention, a blood collection device includes a hub, and a needle extending from the hub, the needle having a cannula having a lumen and defining a central axis therethrough. The needle having a multi-beveled point provided at one end of the cannula. The multi-beveled point includes a primary bevel, two middle bevels, and two tip bevels. Each of the middle bevels extends between the primary bevel and one of the tip bevels. The primary bevel is provided on the cannula at a first angle of inclination with respect to the central axis and a first angle of rotation with respect to the central axis, the two middle bevels are provided on the cannula at a second angle of inclination with respect to the central axis and a second angle of rotation with respect to the central axis, and the two tip bevels are provided on the cannula at a third angle of inclination with respect to the central axis and a third angle of rotation with respect to the central axis. The third angle of inclination is greater than the second angle of inclination and the second angle of inclination is greater than the first angle of inclination. The second angle of rotation is equal to the third angle of rotation.

In certain configurations, the blood collection device further includes a pair of wings extending transversely from the hub. Optionally the pair of wings is rotatable with respect to the hub. In certain configurations the blood collection device further includes a tube holder connected to the hub for receiving a collection container therein.

In certain configurations, the first angle of inclination may be between <NUM>° and <NUM>°. The second angle of inclination may be between <NUM>° and <NUM>°. The third angle of inclination may be between <NUM>°and <NUM>°. In certain configurations, the first angle of rotation is different from the second angle of rotation and the third angle of rotation. Optionally, the first angle of rotation is <NUM>°, and the second angle of rotation and the third angle of rotation are between <NUM>° and <NUM>°.

For purposes of the description hereinafter, spatial orientation terms, if used, shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and embodiments. It is also to be understood that the specific devices illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting. It is understood herein that the identified ranges include the outermost bounds of the ranges recited and all numeric valuations therebetween.

As shown in <FIG>, the present invention is directed a needle <NUM> having a multi-beveled point <NUM>. The needle <NUM> is formed from a tube or cannula <NUM> defining therein a fluid carrying duct or lumen <NUM>. The needle <NUM> may be formed of metal, such as medical grade stainless steel and/or medical grade polymeric materials. The needle <NUM> includes a proximal end <NUM> which can be secured to a medical delivery instrument <NUM>, such as a syringe assembly <NUM> (<FIG>) or a blood collection assembly <NUM> (<FIG>), such as the Vacutainer™ push-button blood collection set commercially available from Becton, Dickinson and Company.

With respect to <FIG>, the needle <NUM> is provided in fluid communication with the interior of the syringe barrel <NUM>, such that transition of the plunger rod <NUM> having a stopper <NUM> connected thereto, into or out of the syringe barrel <NUM> expels fluid from or draws fluid into the syringe barrel <NUM>, respectively, through the needle <NUM>. Similarly, with respect to <FIG>, the needle <NUM> is supported by a hub <NUM>, optionally having rotatable wings <NUM> for easy grasping and manipulation by a user in order to assist in insertion of the needle <NUM> into a patient. The hub <NUM> may provide for fluid communication between the needle <NUM> and a conventional tube holder <NUM>, such as through optional fluid line <NUM>. The tube holder <NUM> is configured for receipt of a specimen collection container, such as an evacuated collection container, as is conventionally known.

The multi-beveled point <NUM> of needle <NUM> defines a fluid opening <NUM> for passage of fluids to and from the fluid carrying lumen <NUM>. The needle <NUM> defines a lumen which extends along and about a central axis <NUM>.

The cannula <NUM> may have a diameter including, but not limited to, <NUM> (<NUM> in. outer diameter, <NUM> in. inner diameter), <NUM> (<NUM> in. outer diameter, <NUM> in. inner diameter), and <NUM> (<NUM> in. outer diameter, <NUM> in. inner diameter), and a wall thickness of <NUM>-<NUM> inch (<NUM>-<NUM>).

As shown in <FIG>, the multi-beveled point <NUM> has a length "L" and has a plurality of individual bevels that together define a beveled face <NUM> about the periphery of the fluid opening <NUM>. The multi-beveled point <NUM> has a primary bevel <NUM>; a pair of middle bevels 28a, 28b; and a pair of tip bevels 30a, 30b. Each of the pair of middle bevels 28a, 28b and each of the pair of tip bevels 30a, 30b are substantially symmetrically formed on opposite sides of the primary bevel <NUM>. Adjacent middle and tip bevels 28a, 30a meet at an intersect 32a demarcating the respective planes at which the middle and tip bevels 28a, 30a are formed. Adjacent middle and tip bevels 28b, 30b likewise meet at an intersect 32b. Tip bevels 30a, 30b meet at pointed tip <NUM> which first enters the skin of a patient or the sealing material associated with a fluid carrying vessel.

Primary bevel <NUM>, middle bevels 28a, 28b, and tip bevels 30a, 30b are formed or otherwise provided on cannula <NUM> by inclining and/or rotating the cannula <NUM> through a series of angles measured relative to the central axis <NUM> and a reference plane <NUM> passing through the central axis <NUM>. The primary bevel <NUM> is formed or otherwise provided on the needle <NUM> by inclining the central axis <NUM> of the needle <NUM> at an angle 26X measured relative to the reference plane <NUM> (see <FIG> and <FIG>). As shown in <FIG>, the reference plane <NUM> is a plane passing through a first point <NUM> midway around the circumference of the cannula <NUM> between the center point <NUM> of the primary bevel <NUM> and the pointed tip <NUM> on one side of the cannula <NUM>, a second point <NUM> midway around the circumference of the cannula <NUM> between the center point <NUM> of the primary bevel <NUM> and the pointed tip <NUM> on an opposing side of the cannula <NUM>, the central axis <NUM> and extending in the longitudinal direction of the cannula <NUM>. The reference plane <NUM> bisects the cannula <NUM>.

The middle bevels 28a, 28b and the tip bevels 30a, 30b can likewise be formed or otherwise provided on the needle <NUM> by inclining the central axis <NUM> of the needle <NUM> at an angle relative to the reference plane <NUM> as well as by rotating the needle <NUM> about the central axis <NUM> at an angle with respect to the reference plane <NUM>. Each of the middle bevels 28a, 28b are formed or otherwise provided on the needle <NUM> by inclining the central axis <NUM> of the needle <NUM> at an angle 28X relative to the reference plane <NUM>, and by rotating the needle <NUM> about the central axis <NUM> in a clockwise and a counterclockwise direction at a rotational angle 28Y relative to the reference plane <NUM> to form middle bevels 28a, 28b, respectively (see <FIG> and <FIG>). This provides the middle bevels 28a, 28b with outwardly directed surfaces. Similarly, the tip bevels 30a, 30b are formed or otherwise provided on the needle <NUM> by inclining the central axis <NUM> of the needle <NUM> at an angle of inclination 30X relative to the reference plane <NUM>, and by rotating the needle <NUM> about the central axis <NUM> in a clockwise and a counterclockwise direction at a rotational angle 34Y (not shown) relative to the reference plane <NUM> to form tip bevels 30a, 30b, respectively (see <FIG> and <FIG>). This provides the tip bevels 30a, 30b with outwardly directed surfaces.

The angle of inclination 30X of the tip bevels 30a, 30b may be greater than the angle of inclination 28X of the middle bevels 28a, 28b, and the angle of inclination 28X of the middle bevels 28a, 28b may be greater than the angle of inclination 26X of the primary bevel <NUM>. The angle of rotation 28Y of the middle bevels 28a, 28b may be equal to the angle of rotation 30Y of the tip bevels 30a, 30b, and the angle of rotation 26Y of the primary bevel <NUM> may be different from the angle of rotation 28Y of the middle bevels 28a, 28b and the angle of rotation 30Y of the tip bevels 30a, 30b.

The angle of inclination 26X of the primary bevel <NUM> may be <NUM>°-<NUM>°, and preferably may be <NUM>°, and the rotational angle 26Y of the primary bevel <NUM> may be <NUM>°.

The angle of inclination 28X of the middle bevels 28a, 28b may be <NUM>°-<NUM>°, <NUM>°-<NUM>°, and preferably may be <NUM>°, and the rotational angle 28Y of the middle bevels 28a, 28b may be <NUM>°- <NUM>°, <NUM>°- <NUM>°, <NUM>°- <NUM>°, and preferably may be <NUM>°.

The angle of inclination 30X of the tip bevels 30a, 30b may be <NUM>-<NUM>°, <NUM>-<NUM>°, and preferably may be <NUM>°, and the rotational angle 30Y of the tip bevels 30a, 30b may be <NUM>°- <NUM>°, <NUM>°- <NUM>°, <NUM>°- <NUM>°, and preferably may be <NUM>°.

When the angle of rotation 26X of the primary bevel <NUM> is <NUM>° as shown in <FIG> and <FIG>, the surfaces of the middle bevels 28a, 28b and the tip bevels 30a, 30b are rotated outwardly from the surface of the primary bevel <NUM> according to their angles of rotation 28Y, 30Y as can be seen in <FIG>.

Inclination and rotation angles for certain needles can be selected for small diameter needles, for example <NUM> and <NUM> (<NUM> in. to <NUM> in. outer diameter), which are used for injection, while the disclosed inclination and rotation angles are used with larger diameter needles, for example <NUM>, <NUM>, and <NUM> (<NUM> in. to <NUM> in. outer diameter), which are used for blood draw. By providing the bevels at the disclosed inclination and rotation angles for the larger diameter needles, the cumulative effect reduces the force needed to penetrate the tissue/insertion medium. The force needed to penetrate the tissue/insertion medium is especially reduced over a needle where the angle of inclination of the primary bevel <NUM> is equal to the angle of inclination of the middle bevels 28a, 28b. Because the needle <NUM> has a more gradual transition from the pointed tip <NUM> formed by the tip bevels 30a, 30b to the primary bevel <NUM>, less penetration force is required to insert the needle <NUM> into a patient's tissue resulting in less discomfort for the patient.

The point length L from the pointed tip <NUM> formed by the tip bevels 30a, 30b to the most proximal portion of the primary bevel <NUM> is from <NUM>-<NUM> inch (<NUM>-<NUM>), and the tip length ℓ from pointed tip <NUM> formed by the tip bevels 30a, 30b to the intersect 32a, 32b between the middle bevels 28a, 28b and the tip bevels 30a, 30b is from <NUM>-<NUM> inch (<NUM>-<NUM>).

The needle <NUM> in accordance with the present invention can be formed from conventional materials such as steel. Medical grade plastics, composites, ceramics, or like materials can be substituted. The needle can be lubricated with various conventional lubricants such as silicone oils to enhance the effects obtained by inventive geometry. The bevels can be formed on the needle by conventional processes such as by grinding.

The respective bevels for the multi-beveled point <NUM> can be formed in any order that results in a continuous beveled face <NUM>. In one aspect, the primary bevel <NUM> and the middle bevels 28a, 28b can be formed before the tip bevels 30a, 30b. In another aspect, the tip bevels 30a, 30b can be formed prior to manufacturing either the middle bevels 28a, 28b or the primary bevel <NUM>. In a further aspect, the middle bevels 28a, 28b can be formed before forming the primary bevel <NUM> and the tip bevels 30a, 30b. For example, the central axis <NUM> of the needle <NUM> may be inclined to the angle of inclination 26X for the formation of the primary bevel <NUM>. The central axis <NUM> of the needle <NUM> is then inclined to an angle of inclination 30X and rotated clockwise and counterclockwise about the central axis <NUM> to an angle of rotation 30Y for formation of the tip bevels 30a, 30b. The central axis <NUM> of the needle <NUM> is re-inclined to an angle of inclination 28X, and rotated about the central axis <NUM> clockwise and counterclockwise to an angle of rotation 28Y for formation of the middle bevels 28a, 28b.

The inventive needle may be used with any suitable assembly for collecting and/or transferring blood or other fluids. Such assemblies, include, but are not limited to, a syringe assembly and a blood collection device. The syringe assembly may include a syringe barrel and the inventive needle may be attached to the syringe barrel.

Claim 1:
A needle (<NUM>) having a multi-beveled point (<NUM>) comprising:
a cannula (<NUM>) having a lumen (<NUM>) and defining a central axis (<NUM>) therethrough, the cannula (<NUM>) having a proximal end (<NUM>) and a distal end and the multi-beveled point (<NUM>) provided at the distal end of the cannula (<NUM>),
wherein the multi-beveled point (<NUM>) comprises:
a primary bevel (<NUM>);
two middle bevels (28a, 28b); and
two tip bevels (30a, 30b) forming a pointed tip (<NUM>),
wherein middle bevel (28a) extends between the primary bevel (<NUM>) and tip bevel (30a), and middle bevel (28b) extends between the primary bevel (<NUM>) and tip bevel (30b),
wherein middle bevel (28a) and middle bevel (28b) are substantially symmetrically formed on opposite sides of the primary bevel (<NUM>), and tip bevel (30a) and tip bevel (30b) are substantially symmetrically formed on opposite sides of the primary bevel (<NUM>), and
wherein adjacent middle bevel (28a) and tip bevel (30a) meet at an intersect (32a), and adjacent middle bevel (28b) and tip bevel (30b) meet at an intersect (32b),
wherein the primary bevel (<NUM>) is provided on the cannula (<NUM>) at a first angle of inclination (26X) with respect to the central axis (<NUM>) and a first angle of rotation (26Y) with respect to the central axis (<NUM>), the two middle bevels (28a, 28b) are provided on the cannula (<NUM>) at a second angle of inclination (28X) with respect to the central axis (<NUM>) and a second angle of rotation (28Y) with respect to the central axis (<NUM>), and the two tip bevels (30a, 30b) are provided on the cannula (<NUM>) at a third angle of inclination (30X) with respect to the central axis (<NUM>) and a third angle of rotation (30Y) with respect to the central axis (<NUM>),
wherein the third angle of inclination (30X) is greater than the second angle of inclination (28X) and the second angle of inclination (28X) is greater than the first angle of inclination (26X),
characterised in that
the second angle of rotation (28Y) is equal to the third angle of rotation (30Y), and
wherein a point length (L) from the pointed tip (<NUM>) to a most proximal portion of the primary bevel (<NUM>) is from <NUM>-<NUM> (from <NUM>-<NUM> inch) and a tip length (ℓ) from the pointed tip (<NUM>) to the intersect (32a, 32b) of each adjacent middle bevel (28a, 28b) and tip bevel (30a. 30b) is from <NUM>-<NUM> (from <NUM>-<NUM> inch).