Patent Publication Number: US-2017368268-A1

Title: Needle with multi-bevel tip geometry

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/090,548 filed Dec. 11, 2014, and of U.S. Provisional Patent Application Ser. No. 62/150,697 filed Apr. 21, 2015, the entireties of which are hereby incorporated herein by reference for all purposes. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to the field of hypodermic needles for medical use, and more particularly to improved tip geometries for needles such as for example pen needles used with injection pens for delivery of insulin or other medications. 
     BACKGROUND 
     Various forms of hypodermic needles are used for the delivery of injectable medications into the body through the skin of a human or animal patient, for sampling of blood, and for other medical and research purposes. Pen needles, for example, are commonly used by healthcare providers and patients for delivery of medications such as insulin for diabetes management. 
     Pen needles typically include a plastic hub with a hollow needle embedded therein. One end of the needle has a sharp tip for injection through the skin of the patient, and the other end is configured to receive medication delivered by an injection pen. The hub of the pen needle typically includes threaded or snap connections for removable attachment to the injection pen, so that the needle can be removed after use and replaced with a new needle for subsequent use of the injection pen. 
     The sharp injection point or tip geometry of a hypodermic needle may affect its function and/or play a part in user preferences. For example, different tip geometries may require more or less force to penetrate the skin during an injection, and/or different users may perceive different pain levels or different tactile feedback resulting from injections with needles having different tip geometries. 
     SUMMARY 
     The present invention relates to improved tip geometries for hypodermic needles or cannulas used, for example, in the delivery of medication, in blood sampling, or in other medical or research applications. In example forms, the invention relates to improved tip geometries for pen needles used in combination with injection pens, such as for example in the administration of insulin for diabetes management. 
     In one aspect, the present invention relates to a multi-beveled needle tip geometry having a proximal bevel formed at a first angle of inclination relative to the longitudinal axis of the needle shaft, a pair of intermediate bevels formed at a different second angle of inclination relative to the longitudinal axis, and a pair of distal bevels formed at a third angle of inclination relative to the longitudinal axis and/or at different angles of rotation relative to the longitudinal axis of the needle shaft and/or relative to a vertical axis generally transverse and orthogonal to the longitudinal axis of the needle. Preferably, no rotational offset is provided between the proximal bevel and the intermediate bevels, and the substantially different first and second angles of inclination define a marked apex or peak at the intersection of the proximal bevel with each of the intermediate bevels. 
     Optionally, one or more radiused transitions are formed at the intersection of adjacent bevels to provide a smoother transition between angular offsets between the bevels, between at least one of the bevels and the lumen of the needle, and/or between at least one of the bevels and an outer surface of the needle. 
     In another aspect, the invention relates to a multi-beveled pen needle including a needle shaft or cannula and a multi-beveled point. Preferably, at least one radiused transition is formed between adjacent bevels, between at least one of the bevels and the lumen, and/or between at least one of the bevels and an outer surface of the cannula such that a clear transition or intersection forming an edge or discontinuity between adjacent surface features is not present. 
     In still another aspect, the invention relates to a method of forming a multi-beveled pen needle tip including: providing a hollow needle or cannula extending from a proximal end to a distal end along a longitudinal axis, the needle comprising a lumen extending therethrough along the longitudinal axis; affixing the proximal end of the needle within a fixture, the distal end being generally free from engagement therewith; positioning the needle at a first inclination angle relative to the longitudinal axis; grinding the distal end to form a proximal bevel; positioning the needle at a second inclination angle relative to the longitudinal axis; grinding the distal end to form a pair of intermediate bevels, the intermediate bevels being generally adjacent the proximal bevel; positioning the needle at a third inclination angle relative to the longitudinal axis; rotating the needle about the longitudinal axis to a first rotational angle relative to a vertical axis, the vertical axis being generally transverse relative to the longitudinal axis; grinding the distal end to form a first distal bevel; rotating the needle about the longitudinal axis to a second rotational angle relative to the vertical axis, the second rotational angle being generally opposite the first rotational angle; grinding the distal end to form a second distal bevel; and forming a smooth and radiused transition between at least two of the bevels, between at least one of the bevels and the lumen, and between at least one of the bevels and an outer surface of the needle. 
     In yet another aspect, the invention relates to a multi-beveled pen needle including a multi-beveled point and at least one smoothed and radiused transition between adjacent bevels, between at least one of the bevels and the lumen, and/or between at least one of the bevels and an outer surface of the needle. The needle generally extends from a proximal end to a distal end along a longitudinal axis and includes an elongate lumen extending therethrough. The multi-beveled point is formed proximal at least one of the ends of the needle and includes at least a proximal bevel and a pair of distal bevels. The proximal bevel is formed at a first angle of inclination relative to the longitudinal axis and the pair of distal bevels are formed generally symmetrically at both a second angle of inclination and corresponding angles of rotation relative to the longitudinal axis and/or a vertical axis positioned transverse to the longitudinal axis. The different first and second angles of inclination result in an apex or peak at bevel intersections, which optionally may be rounded or radiused to provide a smoother transition between bevels. 
     These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of example embodiments are explanatory of example embodiments of the invention, and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a distal-end perspective view of a pen needle according to an example embodiment of the present invention. 
         FIG. 2  is a perspective assembly view of the pen needle of  FIG. 1 , shown with the protective caps or covers separated from the needle hub and with the sharp tip of the needle exposed. 
         FIG. 3  is a perspective view of a needle-tip portion of the pen needle of  FIG. 1 , showing a needle-tip geometry according to an example embodiment of the invention. 
         FIG. 4  is a detailed view of the needle-tip portion of  FIG. 3 , showing smooth radiused transitions between the bevels, between the bevels and the interior surface of the lumen, and between the bevels and the outer periphery of the needle. 
         FIG. 5  is a further-detail and different-perspective view of the needle-tip portion of  FIG. 3 . 
         FIG. 6A  is a side view of the needle-tip portion of  FIG. 3 , showing the inclination angles of the proximal and intermediate bevels. 
         FIG. 6B  is a side perspective view of the needle-tip portion of  FIG. 6A , showing the inclination angle of the distal bevels. 
         FIG. 7  is a partial cross-sectional view of the needle-tip portion of  FIG. 6A  taken along line  7 - 7 , showing the angle of rotation of the distal bevels. 
         FIG. 8  is a top view of the needle-tip portion of  FIG. 3 . 
         FIG. 9  is a perspective view of a needle tip according to another example embodiment of the present invention. 
         FIG. 10  is a perspective view of the needle-tip portion of  FIG. 9 , showing smooth radiused transitions between the bevels, between the bevels and the interior surface of the lumen, and between the bevels and the outer periphery of the needle. 
         FIG. 11  is a detail view of the needle-tip portion of  FIG. 9 . 
         FIG. 12A  is a side view of the needle-tip portion of  FIG. 9 , showing the inclination angle of the proximal bevel. 
         FIG. 12B  is a side perspective view of the needle-tip portion of  FIG. 12A , showing the inclination angle of the distal bevels. 
         FIG. 13  is a partial cross-sectional view of the needle-tip portion of  FIG. 12A  taken along line  13 - 13 , showing the angle of rotation of the distal bevels. 
         FIG. 14  is a top view of the needle-tip portion of  FIG. 9 . 
         FIG. 15A  is a distal-end perspective view of a pen needle according to another example embodiment of the present invention. 
         FIG. 15B  is a perspective assembly view of the pen needle of  FIG. 15A , shown with the protective caps or covers separated from the needle hub and with the sharp tip of the needle exposed. 
         FIGS. 16A-16D  show top, side, side perspective and end views, respectively, of a needle, for example for use in a pen needle assembly according to  FIG. 15A , having a multi-bevel needle tip geometry according to a further example embodiment of the invention. 
         FIGS. 17A and 17B  show detailed perspective and top views of a needle having a multi-bevel needle tip geometry according to an example embodiment of the invention. 
         FIGS. 18A and 18B  show detailed side and top views of a needle having a multi-bevel needle tip geometry according to an example embodiment of the invention. 
         FIGS. 19A and 19B  show detailed side and top views of another needle having a multi-bevel needle tip geometry according to an example embodiment of the invention. 
         FIG. 20  shows a detailed top view of another needle having a multi-bevel needle tip geometry according to an example embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     The present invention may be understood more readily by reference to the following detailed description of example embodiments in conjunction with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein. 
     Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
     With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,  FIG. 1  shows a pen needle P in example form.  FIG. 2  shows the pen needle P, with its needle guard G and cover C removed from the hub H, to expose the sharp needle tip N. In some example forms, the needle guard G and/or the cover C are/is color tinted. 
       FIGS. 3-8  show a sharp point or tip geometry of a needle  10  according to an example embodiment of the present invention. In example forms, the needle  10  can comprise the needle N of a pen needle P such as is shown in  FIGS. 1 and 2 , the needle of a standard hypodermic syringe, or the needle of various other devices for injection or other medical or research applications. The needle  10  generally comprises a tube or cannula  12  defining a fluid-carrying duct or lumen  14  extending therethrough along a longitudinal axis A from a proximal end  16  to a distal end  20 . In typical embodiments, both the cannula  12  and the lumen  14  (i.e., the inner and outer wall surfaces of the cannula) are generally cylindrical in shape and concentrically or coaxially positioned relative to each other to generally define a substantially continuous wall thickness along the length of the cannula  12 . The proximal end  16  and/or medial portions of the needle  10  are configured for attachment to the hub of a pen needle, to the barrel of a syringe assembly, or to another device or fixture. The distal end  20  preferably comprises a multi-beveled point  22  including a plurality of beveled faces, for example as detailed herein. While generally described herein with respect to embodiments taking the form of a pen needle tip geometry, the tip geometry of the present invention may also be adapted to use in connection with various other items, such as for example hypodermic needles, lancets, catheters and the like. 
     The multi-beveled point  22  is generally characterized by an axial length L (see  FIG. 8 ), and the plurality of beveled faces thereof are generally formed around/along a periphery  26  of the lumen  14 . The plurality of bevels may contiguously bound the distal opening of the lumen  14  or may be spaced a distance from the edge of the lumen. In the embodiment of  FIGS. 3-8 , the multi-beveled point  22  comprises a proximal bevel  30 , a pair of intermediate bevels  32   a ,  32   b , and a pair of distal bevels  34   a ,  34   b . In the depicted embodiment, the pair of intermediate bevels  32   a ,  32   b  and the pair of distal bevels  34   a ,  34   b  are symmetrically formed relative to the proximal bevel  30 , but in alternate embodiments the bevel configuration may be asymmetric. 
     Optionally, a radiused, rounded, or otherwise smooth transition zone is formed between the bevels (generally axially), between the bevels and the lumen (generally radially), and/or between the bevels and the outer periphery of the cannula  12  (generally radially). For example, as depicted in  FIGS. 4 and 5 , a first smooth transition  40   a  is provided between the distal bevels  34   a ,  34   b , meeting together at an longitudinal apex  36 . A second smooth transition  40   b  is provided between the distal bevel  34   a  and the intermediate bevel  32   a , a third smooth transition  40   c  is provided between the distal bevel  34   b  and the intermediate bevel  32   b , a fourth smooth transition  40   d  is provided between the intermediate bevel  32 α and a portion of the proximal bevel  30 , and a fifth smooth transition  40   e  is provided between the intermediate bevel  32   b  and a portion of the proximal bevel  30 . In example embodiments, a smooth transition  42  is also provided between each of the bevels positioned along the periphery  26  of the lumen  14  and an interior surface  15  of the lumen  14  (e.g., bevel-to-intralumen transition), and a smooth transition  44  is provided between the intersection of each of the bevels and the outer surface or periphery of the cannula  12 . In example forms, the smooth transitions generally comprise a radius of curvature R of between about R 0.0001-R 0.035 millimeters, for example about R 0.02 millimeters. Preferably, the smooth transitions avoid a sharp edge or clearly defined intersection between the bevels and other surfaces of the needle tip such that transitions between the surfaces are smooth. The smooth transitions may be formed, for example, by bead blasting, grinding, polishing, coating or otherwise treating the needle surface(s). 
       FIGS. 6A, 6B and 7  show further details of the multi-bevel point  22 . As depicted in  FIG. 6A , the proximal bevel  30  is formed at a first inclination angle  30 α and the intermediate bevels  32   a ,  32   b  are formed at a substantially different (i.e., not substantially equal) second inclination angle  32 α, the angles  30 α and  32 α being defined relative to the longitudinal axis A of the needle shaft. The proximal and intermediate bevels  30 ,  32   a - b  are preferably formed at the same rotational angle (i.e., with no rotational offset about the longitudinal axis A). The first inclination angle  30 α may be, for example, between about 7.3-7.7 degrees relative to the axis A, and the second inclination angle  32 α may be, for example, between about 9.3-9.7 degrees relative to the axis A, thus defining an angular offset or difference of about 2 degrees (i.e., about 20%-25% relative difference in the angles  30 α and  32 α). In alternate embodiments, the first inclination angle  30 α is, for example between about 6.0-9.0 degrees, and the second inclination angle  32 α is, for example between about 8.0-11.0 degrees. In still other embodiments, the first inclination angle  32 α is about 8 degrees and the second inclination angle  32 α is about 10 degrees, resulting in a difference of about 2 degrees (i.e., about 22% different). Preferably, the angular offset or difference between the first inclination angle  30 α and the second inclination angle  32 α is at least about 1.0-2.0 degrees or more, or at least about a 10%-20% difference or more. Provision of substantially unequal first and second inclination angles  30 α and  32 α in this manner results in a marked apex or peak at the intersections of the proximal bevel  30  and the intermediate bevels  32   a ,  32   b , in the vicinity of the rounded or smooth transitions  40   d  and  40   e.    
     With reference to  FIG. 6B , the distal bevels  34   a ,  34   b  are formed at a third inclination angle  34 α relative to the longitudinal axis A, of for example between about 18-19 degrees. In alternate embodiments, the third inclination angle  34 α is between about 17-20 degrees relative to the longitudinal axis A, or for example between about 22.2-22.3 degrees. Preferably, prior to forming the distal bevels  34   a ,  34   b , the pen needle  10  is rotated about the longitudinal axis A in the clockwise and counterclockwise directions respectively, to form the distal bevels  34   a ,  34   b  at substantially different rotational angles (as well as at an inclination angle as described above) relative to the proximal and intermediate bevels  30 ,  32   a ,  32   b . As depicted in  FIG. 7 , the entire rotation of the needle  10  between the first distal bevel  34   a  and the second distal bevel  34   b  (shown as rotation angle  34 β) is about 130 degrees relative to a vertical axis B. Thus, to form the first distal bevel  34   a , the needle is rotated about the longitudinal axis A in the clockwise direction a rotational angle of about 65 degrees and inclined at the inclination angle  34 α. Similarly, to form the second distal bevel  34   b , the needle  10  is rotated about the longitudinal axis A in the counterclockwise direction (from the 65 degrees clockwise position) about 130 degrees in the counterclockwise direction while remaining at the inclination angle  34 α. Thus, in example forms, the rotational angle for forming the distal bevels  34   a ,  34   b  is generally provided by rotating the needle  10  about 65 degrees in both the clockwise and counterclockwise directions about the longitudinal axis A. Optionally, the rotational angles can be between about 55-75 degrees in the clockwise and counterclockwise directions. 
     The smooth transitions between the bevels may be configured such that an angle  30 β is defined between the vertical axis B and the smooth transitions  40   d ,  40   e , and an angle  32 β is provided between the vertical axis B and the smooth transitions  40   b ,  40   c . In example embodiments, the angle  30 β is about 90 degrees and the angle  32 β is about 73 degrees. Preferably, since the angle of rotation between the proximal bevel  30  and the intermediate bevels  32   a ,  32   b  is exactly (or at least substantially) zero, the angle  30 β will generally remain close to 90 degrees. And, since the needle  10  is rotated in the clockwise and counterclockwise directions prior to forming the distal bevels  34   a ,  34   b , the angle  32 β will generally be between about 60 degrees to about 80 degrees relative to the vertical axis B. 
     With reference to  FIG. 8 , in example embodiments, the overall axial length L of the multi-beveled surface  22  is between about 1.3-1.45 millimeters. In further example embodiments, the length L is between about 1.32-1.42 millimeters. In further example embodiments, the length L is between about 1.20-1.60 millimeters. In example embodiments, the length  30 L of the proximal bevel  30  is between about 0.800-0.900 millimeters, the length  32 L of the intermediate bevels  32   a ,  32   b  is between about 0.200-0.250 millimeters, and the length  34 L of the distal bevels  34   a - b  is between about 0.320-0.450 millimeters. In further example embodiments, the length  30 L of the proximal bevel  30  is between about 0.810-0.880 millimeters, the length  32 L of the intermediate bevels  32   a ,  32   b  is between about 0.229-0.236 millimeters, and the length  34 L of the distal bevels  34   a - b  is between about 0.360-0.400 millimeters. In further example embodiments, the length  30 L of the proximal bevel  30  is between about 0.600-1.050 millimeters, the length  32 L of the intermediate bevels  32   a ,  32   b  is between about 0.110-0.350 millimeters, and the length  34 L of the distal bevels  34   a - b  is between about 0.200-0.620 millimeters. In example embodiments, the length  30 L 1  of the proximal bevel  30  (measured between the peak and valley of the proximal bevel  30 ) is between about 0.350-0.390 millimeters. In further example embodiments, the length  30 L 1  is between about 0.355-0.383 millimeters. In further example embodiments, the length  30 L 1  is between about 0.325-0.400 millimeters. As such, in typical embodiments the multi-beveled point forms an elongated distal opening in communication with the lumen, the proximal bevel extends longitudinally from a proximal-most part of the multi-beveled point continuously along opposing elongated sides of the multi-beveled point, and the multi-beveled point has an overall axial length and the proximal bevel has an axial length that is at least half the overall axial length of the multi-beveled point. 
     The proximal, intermediate and distal bevels  30 ,  32   a - b ,  34   a - b  can also be defined by their respective arc lengths  30 AL,  32 AL, and  34 AL, as shown in  FIG. 8 . The arc length is generally defined along the interior edges of the bevels, along the periphery  26  of the lumen  14 , between the transitions between adjacent bevels. In one example form, the arc length  30 AL of the proximal bevel  30  is between about 0.930-1.050 millimeters, the arc length  32 AL of the intermediate bevels  32   a - b  is between about 0.220-0.255 millimeters, and the arc length  34 AL of the distal bevels  34   a - b  is between about 0.175-0.245 millimeters. In another example form, the arc length  30 AL of the proximal bevel  30  is between about 0.944-1.034 millimeters, the arc length  32 AL of the intermediate bevels  32   a - b  is between about 0.232-0.240 millimeters, and the arc length  34 AL of the distal bevels  34   a - b  is between about 0.203-0.213 millimeters. In another example form, the arc length  30 AL of the proximal bevel  30  can be between about 0.650-1.550 millimeters, the arc length  32 AL of the intermediate bevels  32   a - b  can be between about 0.150-0.350 millimeters, and the arc length  34 AL of the distal bevels  34   a - b  can be between about 0.100-0.315 millimeters. 
     The pen needle  10  of the present invention can be formed from a steel material, for example a stainless steel, for example by drawing, molding or other manufacturing processes. In example forms, the needle  10  comprises an outer diameter OD and an inner diameter ID. The outer diameter OD is measured across the outer peripheral surface of the cannula  12  and the inner diameter ID is measured across the inner surface  15  of the lumen  14 . In example forms, the outer diameter OD of the needle  10  is generally between about 0.1770-0.3460 millimeters, or for example from about 29 gauge to about 34 gauge, and the inner diameter is between about 0.0550-0.2260 millimeters. In further example forms, the outer diameter OD is between about 0.1778-0.3430 millimeters and the inner diameter ID is between about 0.0578-0.2230 millimeters. In further example forms, the outer diameter OD can be between about 0.1700-0.3500 millimeters and the inner diameter ID can be between about 0.0500-0.2300 millimeters. In example forms, the pen needle is about 4-25 millimeters in overall length. The chart below shows example dimensions of several gauge needles according to example embodiments of the present invention. 
     
       
         
           
               
               
               
               
               
               
               
               
               
             
               
                   
               
               
                   
                   
                   
                   
                   
                 Wall 
                 Wall 
                   
                   
               
               
                   
                 OD 
                   
                 OD 
                 OD 
                 Thickness 
                 Thickness 
                 ID  
                 ID 
               
               
                 Gauge 
                 Nominal 
                 Tolerance 
                 Small 
                 Large 
                 Minimum 
                 Regular 
                 Small 
                 Largest 
               
               
                   
               
             
            
               
                 29 
                 0.3366 
                 0.0064 
                 0.3302 
                 0.3430 
                 0.0600 
                 0.0800 
                 0.1702 
                 0.2230 
               
               
                 30 
                 0.3112 
                 0.0064 
                 0.3048 
                 0.3176 
                 0.0600 
                 0.0800 
                 0.1448 
                 0.1976 
               
               
                 31 
                 0.2604 
                 0.0064 
                 0.2540 
                 0.2668 
                 0.0600 
                 0.0800 
                 0.0940 
                 0.1468 
               
               
                 32 
                 0.2350 
                 0.0064 
                 0.2286 
                 0.2414 
                 0.0500 
                 0.0600 
                 0.1086 
                 0.1414 
               
               
                 33 
                 0.2096 
                 0.0064 
                 0.2032 
                 0.2160 
                 0.0500 
                 0.0600 
                 0.0832 
                 0.1160 
               
               
                 34 
                 0.1842 
                 0.0064 
                 0.1778 
                 0.1906 
                 0.0500 
                 0.0600 
                 0.0578 
                 0.0906 
               
               
                   
               
            
           
         
       
     
     In example forms, the needle  10  of the present invention is generally manufactured in quantity, for example between about 50-1000 needles at a time in an automated process. Typically, an arm or other articulating structure comprises a system of fixtures for holding needle blanks, each of which is ground several times for form the needle tip resulting in the needle  10 . In example forms, the bevels of the multi-beveled tip are ground by a disc-like grinding wheel or a belt. In example form, the arm holding the fixtures is positioned in close proximity to the grinder to allow for the grinder to provide the multi-beveled face on each of the needles sequentially or simultaneously. Preferably, the fixture system provides for rotation thereof such that the to-be needle can be rotated to form the distal bevels  34   a - b . Adjustment to the inclination angle may be provided by angular movement of the arm and/or angular change of the inclination angle of each of the fixtures relative to the arm. 
     In example methods of manufacture, the end of a needle blank may start with a flat end face prior to being ground. The needle blank is then positioned at the inclination angle  30 α relative to the longitudinal axis A and a grinder forms the proximal bevel  30 . While remaining at the same angle of rotation, the inclination angle of the needle blank is changed to the inclination angle  32 α relative to the longitudinal axis A. The grinder then forms the intermediate bevels  32   a ,  32   b . The remaining distal bevels  34   a - b  are then formed, which requires adjustment to the inclination angle and the angle of rotation of the needle blank. In example form, the needle is adjusted to the inclination angle  34 α and then rotated in the clockwise direction about ½  34 β, for example from the vertical axis B to the limit of  34 β in the clockwise direction. The grinder then forms the first distal bevel  34   a . The needle is then rotated the entire length of the rotation angle  34 β in the counterclockwise direction and the grinder forms the second distal bevel  34   b . Alternatively, the manufacturing process and/or the order of the steps to form the bevels can vary. 
     After the bevels are formed on the tip of the needle  10 , the needle preferably goes through a bead blasting process whereby very small glass beads are projected onto the multi-beveled point such that any edges, intersections or transitions between bevels and adjacent surfaces are radiused, rounded, or otherwise smoothed. In one form, the projection of glass beads is not necessarily concentrated on a particular portion of the multi-beveled point  22 , but instead generally projected at the point  22  in a direction generally perpendicular to the longitudinal axis A. In example forms, the spray of glass beads is controlled by the equipment and can be adjusted from a direction generally parallel to the extension of the needle  10  to a direction generally perpendicular to the extension of the needle  10  (including any angle therebetween). According to one example form, the angle of the spray of the glass beads is configured to be at about 30 degrees relative to the extension of the needle  10  (e.g., from being parallel therewith). The needle  10  then goes through an alkaline bath, an ultrasonic cleaning process, an acid bath, an electropolishing process, a cleaning process, and a passivation process. Preferably, these processes ensure that the needle is polished, smooth, free from burrs, and less resistant to corrosion. Optionally, after processing the needle (e.g., electropolishing, cleaning, and passivation), the needle undergoes a visual or machine inspection process to ensure that quality standards have been met. Generally, the inspection process comprises comparing the needle and its multi-beveled point against a sample or image of a satisfactory needle having targeted specifications. For example, in some example forms, the needle  10  is measured and the measurements are compared to a 2-dimensional dimensioned print of the needle. If the needle is within a specified range or tolerance of the target specifications, the needle passes the inspection and is assembled to form a pen needle, syringe or other item, and further treated and/or packaged for delivery. 
       FIGS. 9-14  show a pen needle  110  according to another example embodiment of the present invention. The pen needle  110  is in many aspects substantially similar to the pen needle  10  as described above, but comprises a three-bevel tip geometry rather than the five-bevel tip geometry described above. The pen needle  110  comprises a proximal bevel  130  and a pair of distal bevels  134   a ,  134   b . Generally, the pen needle  110  comprises an elongate cannula  112  having a lumen  114  extending therethrough, which extends along a longitudinal axis A from a proximal end  116  to a distal end  120 . 
     A rounded, radiused, or otherwise smooth transition is optionally provided between the bevels, between the bevels and the lumen, and/or between the bevels and the outer periphery of the cannula  112 . For example, as depicted in  FIGS. 10-11 , a first smooth transition  140   a  is provided between the distal bevels  134   a ,  134   b , which meet together at a longitudinal apex  136 . A second smooth transition  140   b  is provided between the distal bevel  134   a  and a portion of the proximal bevel  130 , and a third smooth transition  140   c  is provided between the distal bevel  134   b  and a portion of the proximal bevel  130 . A smooth transition  142  is also optionally provided between each of the bevels positioned along the periphery  126  of the lumen  114  and an interior surface  115  of the lumen  114  (e.g., bevel to intralumen transition), and a smooth transition  144  provided between the intersection of each of the bevels and the outer surface or periphery of the cannula  112 . 
       FIGS. 12A, 12B and 13  show greater details of the multi-bevel point  122 . In the depicted embodiment of  FIG. 12A , the proximal bevel  130  is formed at a first inclination angle  130   a , defined relative to the longitudinal axis A. For example, in one example embodiment, the first inclination angle  130 α is between about 7.3-7.7 degrees relative to the axis. In alternate embodiments, the first inclination angle  130 α is between about 6.0-9.0 degrees. In the depicted embodiment of  FIG. 12B , the distal bevels  134   a ,  134   b  are formed at a second inclination angle  134 α relative to the longitudinal axis A, for example between about 18.0-19.0 degrees. In alternate embodiments, the second inclination angle  134 α is between about 18.3-18.9 degrees. Optionally, the second inclination angle  134 α is between about 17.0-20 degrees relative to the longitudinal axis A. Preferably, prior to forming the distal bevels  134   a ,  134   b , the pen needle  110  is rotated about the longitudinal axis A in both the clockwise and counterclockwise directions respectively, such that the distal bevels  134   a ,  134   b  are formed at a substantially different rotational angle (and at a different inclination angle as described above) relative to the proximal bevel  130 . As depicted in  FIG. 13 , the entire rotation of the needle  110  between the first distal bevel  134   a  and the second distal bevel  134   b  (shown as rotation angle  134 β) is about 130 degrees relative to a vertical axis B. Thus, to form the first distal bevel  134   a , the needle is rotated about the longitudinal axis A in the clockwise direction about 65 degrees and inclined at the inclination angle  134 α. Similarly, to form the second distal bevel  134   b , the needle  110  is rotated about the longitudinal axis A in the counterclockwise direction (from the 65 degrees clockwise position) about 130 degrees in the counterclockwise direction while remaining at the inclination angle  134 α. Thus, in example forms, the rotational angle for forming the distal bevels  134   a ,  134   b  is generally provided by rotating the needle  110  about 65 degrees in both the clockwise and counterclockwise directions about the longitudinal axis A. Optionally, the rotational angle can be between about 55-75 degrees in the clockwise and counterclockwise directions. 
     As depicted, the smooth transitions between the bevels may be configured such that an angle  130 β is defined between the vertical axis B and the smooth transitions  140   b ,  140   c . In example forms, the angle  130 β is about 73 degrees. Since the needle  110  is rotated in the clockwise and counterclockwise directions prior to forming the distal bevels  134   a ,  134   b , the angle  130 β will generally be between about 60 degrees to about 85 degrees relative to the vertical axis B. 
     As depicted in  FIG. 14 , in example embodiments, the length L of the multi-beveled surface  122  is between about 1.30-1.45 millimeters. In further example embodiments, the length L is between about 1.32-1.42 millimeters. In further embodiments, the length L can be between about 1.20-1.60 millimeters. In example embodiments, the length  130 L of the proximal bevel  130  is between about 0.800-0.900 millimeters and the length  134 L of the distal bevels  134   a - b  is between about 0.320-0.450 millimeters. In further example embodiments, the length  130 L of the proximal bevel  30  is between about 0.810-0.880 millimeters and the length  134 L of the distal bevels  34   a - b  is between about 0.360-0.400 millimeters. In further example embodiments, the length  130 L of the proximal bevel  130  is between about 0.600-1.050 millimeters and the length  134 L of the distal bevels  134   a - b  is between about 0.200-0.620 millimeters. In example embodiments, the length  130 L 1  of the proximal bevel  30  (measured between the peak and valley of the proximal bevel  130 ) is generally between about 0.350-0.390 millimeters. In further example embodiments, the length  130 L 1  is between about 0.355-0.383 millimeters. And in further example embodiments, the length  130 L 1  is between about 0.325-0.400 millimeters. 
     The proximal and distal bevels  130 ,  134   a - b  can also be defined by their respective arc lengths  130 AL,  134 AL. The arc length is generally defined along the interior edges of the bevels around the periphery  126  of the lumen  114 , between transitions between the bevels. In one example form, the arc length  130 AL of the proximal bevel  130  is between about 0.930-1.050 millimeters and the arc length  134 AL of the distal bevels  134   a - b  is between about 0.175-0.245 millimeters. In example form, the arc length  130 AL of the proximal bevel  130  is between about 0.944-1.034 millimeters and the arc length  134 AL of the distal bevels  134   a - b  is between about 0.203-0.213 millimeters. In further example form the arc length  130 AL of the proximal bevel  130  is between about 0.650-1.550 millimeters and the arc length  134 AL of the distal bevels  134   a - b  is between about 0.100-0.315 millimeters. 
     In example embodiments, the outer diameter OD of the needle  110  is generally between about 0.1770-0.3460 millimeters, or for example between about 29 gauge to about 34 gauge, and the inner diameter is between about 0.0550-0.2260 millimeters. In further example embodiments, the outer diameter OD is between about 0.1778-0.3430 millimeters and the inner diameter ID is between about 0.0578-0.2230 millimeters. In still further example embodiments, the outer diameter OD can be between about 0.1700-0.3500 millimeters and the inner diameter ID can be between about 0.0500-0.2300 millimeters. In example forms, the pen needle is about 4-25 millimeters in overall length. The chart above (see paragraph [0047]) shows example dimensions of several gauge needles according to example embodiments of the present invention. 
       FIGS. 15A-20  show additional features and embodiments of pen needles and needle tip geometries according to further example forms of the invention. In example forms, a pen needle  210  comprises a needle cannula  212  attached to a hub  214 , a shield  216  and a container or cover  218 . The needle  212  has a distal end  220  comprising a multi-beveled point  222 . The multi-beveled point  222  comprises a plurality of beveled faces including a proximal bevel  230 , a pair of intermediate bevels  232 , one or more distal bevel(s)  234 , and a back bevel  236 . In example embodiments, the proximal bevel  230 , intermediate bevels  232 , and distal bevel  234  can be configured substantially similar to the respective bevels of the embodiments described above. In further example embodiments, one or more of the proximal bevel  230 , the intermediate bevels  232 , and the distal bevel(s)  234  are formed at different angles of inclination relative to one another and/or at rotational angles relative to one another. 
     The back bevel  236  is preferably formed on the rotationally opposite side or face of the needle cannula  212  (i.e., at a rotational orientation of about 180° about the axis C of the cannula) from the proximal bevel  230 , intermediate bevels  232 , and distal bevel  234 . The back bevel  236  is preferably ground to a depth into the wall thickness of the cannula  212  sufficient to define a sharp leading edge  240  at the tip of the point  222  where the plane of the back bevel intersects the plane of the distal bevel  234 , defining a chisel-tip geometry. Optionally, the back bevel  236  is formed at a slightly angularly offset (from 180°) rotational orientation relative to the distal bevel  234 , to form an obliquely angled (relative to the axis C of the cannula) leading edge  240 . In the embodiment depicted in  FIG. 16 c   , the back bevel is ground at a rotational offset of about 152° from the distal bevel  234 . In alternate embodiments, the rotational offset can be, for example, within a range of +/−45°, +/−30°, +/−15°, +/−5° and/or other offset from exactly 180°, to vary the angle of the leading edge  240  relative to the axis C of the cannula. Or alternatively, the back bevel  236  can be formed at a 180° rotational offset from the distal bevel  234  to form a leading edge perpendicular or transverse to the axis C of the cannula. The needle  210  can be formed in similar fashion as described above, in various different gauges, lengths, needle formats, etc., as well as various different bevel geometries and tip configurations, in example embodiments within the scope of the invention. 
     While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.