Intravenous cannula

Abstract

An intravenous cannula apparatus configured to prevent accidental needle stick injuries includes a catheter assembly and a needle guard assembly. The catheter assembly includes a catheter hub having a coaxial recess configured to engage a distal portion of the needle guard assembly. The intravenous cannula apparatus configured to prevent needle stick injuries includes a safety release component at a distal end of the needle guard assembly. The safety release component includes a movable locking element configured to fit within an annular groove defined by a proximal portion of the catheter hub upon movement of the needle through the safety release component. Proximal retraction of the needle through the safety release component displaces the movable locking element from the annular groove, thereby decoupling the catheter assembly from the needle guard assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No. 17 / 592,795, entitled "INTRAVENUS CANNULA," filed on February 4, 2022, which in turn claims priority to Indian Patent Application No. 202211002363, entitled "INTRAVENUS CANNULA," filed on January 14, 2022, each of which is incorporated herein by reference in its entirety for all purposes. [Technical field]

[0002] The present disclosure relates to medical devices. Embodiments include an venous cannula configured to prevent needle stick injuries. Embodiments also include an venous cannula with an improved catheter coupling and release mechanism configured to facilitate reliable and safe disengagement of a catheter assembly from a needle guard assembly after placement of a distal end of the catheter assembly within a target blood vessel. [Background technology]

[0003] Intravenous cannulas are used to inject and / or withdraw fluids, such as medications, nutrients, or blood, directly into and / or from a patient's blood vessels. Intravenous cannulas typically include a catheter assembly and a needle insertion or protection assembly. A distal portion of a catheter tube contained within the catheter assembly can be introduced into the blood vessel using a needle, after which the cannula can be secured to the patient's skin with an adhesive, which may be, for example, tape. The catheter tube contained within such devices generally defines a lumen dimensioned to accommodate the insertion and retraction therethrough of a disposable hollow bore needle. For this reason, the device is sometimes referred to as an over-the-needle cannula.

[0004] Once the distal portion of the catheter is inserted into the patient's vasculature, a disposable needle passing through the catheter extends distally to puncture the patient's vein or artery, thereby providing an access point for the cannula to deliver or withdraw the desired fluid. The needle is then withdrawn, leaving the catheter assembly in place as a hub, which can be used to connect to various external interfaces, such as fluid bottles. The catheter hub can also be capped for later use.

[0005] Despite their widespread and long-standing use, existing intravenous cannulas remain problematic in a variety of ways. For example, cannulas often lack the safety features necessary to prevent the catheter needle from injuring the medical professional before or after the distal tip of the needle is inserted into the patient's vasculature. Due to the high prevalence of communicable diseases among hospitalized patients requiring catheter-based therapy, the consequences of an inadvertent needlestick injury can be severe.

[0006] Cannulas have been designed to solve this problem by enclosing a portion of the needle in a needle guard housing that is movable relative to the elongated needle tube, which may be dimensioned to accommodate the entire length of the needle before and after deployment in the patient's vasculature. The elongated needle tube may constitute a component of the needle insertion assembly that may be temporarily coupled to the catheter assembly such that the needle may be retracted into the elongated needle tube and the needle insertion assembly disengaged from the catheter assembly after the distal portion of the catheter is positioned in the blood vessel. Devices configured in this manner are vulnerable to untimely separation of the catheter assembly from the needle insertion assembly, as they often rely entirely on sufficient, but not excessive, friction to couple the two components together.

[0007] Indian Patent Application No. 3031 / DEL / 2014 (hereinafter referred to as the '3031 patent application) provides another example of an existing defective catheter device. One problem associated with the device disclosed therein is that the needle cover does not disengage from the catheter hub when the needle is retracted from the needle cover, meaning that more force is required to disengage the needle cover from the catheter hub. Furthermore, the needle disclosed in the '3031 patent application does not engage the needle cover with the catheter hub, hindering the overall functionality of the catheter. This defect forces the operator to manipulate the catheter device to extract the needle cover from the hub, which may damage the target blood vessel and cause pain.

[0008] The present disclosure is directed to an improved cannula designed to overcome the aforementioned problems in addition to providing other technical advantages. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Indian Patent Application No. 3031 / DEL / 2014 Summary of the Invention [Problem to be solved by the invention]

[0010] One objective of the present disclosure is to prevent needle stick injuries that may be incurred by medical professionals before or after puncturing a patient's vein or artery. [Means for solving the problem]

[0011] An embodiment of an venous cannula device described herein can include a catheter assembly configured to mate with a needle guard assembly, both components configured to accommodate passage of a needle therethrough. An embodiment of a catheter assembly can include a catheter hub having a proximal end and a distal end with a coaxial recess. "Coaxial" refers to tubes within tubes, whose axes extend in the same direction, and the axes in a coaxial arrangement can be, but do not have to be, coincident.

[0012] An embodiment of the cannula device may include a flashback chamber configured to receive proximally flowing blood indicating successful puncture of a target vessel by a needle extending distally from the cannula.

[0013] In some embodiments, the cannula device can include a flashback chamber having a porous filter and a cover to allow air to escape and blood to flow through the flashback chamber.

[0014] In some embodiments, the device may include a needlestick safety device or component.

[0015] In some embodiments, the needle guard assembly can include an elongated tubular member and a needle hub with a needle holder disposed inside the elongated tubular member. A distal end of the needle holder can be connected to a needle configured to puncture a target blood vessel within a patient. The embodiments can also include a safety release component secured or coupled to the distal end of the elongated tubular member. The safety release component can be configured to releasably couple with the catheter hub, thereby coupling the catheter assembly with the needle guard assembly. The safety release component can include one or more locking elements at or near its distal end, which can be configured to protrude and / or move radially outward when a needle is inserted within the safety release component. The outward protrusion and / or movement of the locking elements can cause the locking elements to fit within and thus engage an annular groove defined by a proximal portion of the catheter hub, thereby forming a locking engagement and / or close-fitting relationship between the needle guard assembly and the catheter assembly when the needle passes through the safety release component to puncture a blood vessel of a patient. When the needle is retracted through the catheter assembly and safety release component after puncturing a patient's blood vessel, the locking element can retract and / or displace from the annular groove in the catheter hub, thereby disengaging the safety release component and the catheter hub. This disengagement allows for separation of the catheter assembly from the needle guard assembly only if the needle is enclosed within the safety release component and the needle guard assembly. In this manner, embodiments of the cannula device disclosed herein can shield the distal tip of the needle as it is withdrawn from the patient to prevent inadvertent needlestick injuries.

[0016] In some embodiments, the safety release component can define a groove in an outer surface for receiving one or more locking elements.

[0017] In some embodiments, the locking element or elements may be solid and spherical. The locking elements may also be made of a rigid or substantially rigid material, such as a metal, for example, stainless steel and / or Nitinol.

[0018] In some embodiments, each groove of the safety release component can have a diameter equal to or greater than the diameter of the locking element.

[0019] In some embodiments, the proximal end of the safety release component can have a circular base portion defining a central bore and secured to the distal end of the elongate tubular member.

[0020] In some embodiments, the safety release component can include a tubular portion extending from a circular base portion and defining an axial bore configured to accommodate passage of a needle to and from the target insertion site.

[0021] In some embodiments, a groove defined by an outer surface of the tubular portion of the safety release component can extend toward the axial bore of the safety release component.

[0022] In some embodiments, the solid spherical element of the safety release component can be configured to extend outwardly to engage with an annular groove in the catheter hub, thereby forming a locking engagement and close-fitting relationship between the elongated tubular member and the catheter assembly when the needle passes through the safety release component in response to puncturing a patient's blood vessel.

[0023] In some embodiments, proximal retraction of the needle through the safety release component after puncturing a patient's blood vessel causes a locking element of the safety release component to disengage from an annular groove defined by the catheter hub, thereby disengaging the safety release component (and needle guard assembly) from the catheter assembly. Disengagement of the safety release component from the catheter assembly allows separation of the catheter assembly from the needle guard assembly only after the distal tip of the needle is fully enclosed within the safety release component.

[0024] In some embodiments, the safety release component included in the needle guard assembly can include a safety clip. The safety clip can be outwardly biased to engage at least one interlocking flange defined in a body portion of the needle guard assembly. The outward bias of the safety clip can allow the needle member to extend through the needle guard assembly and the catheter hub. Upon withdrawal of the needle member from the proximal end of the catheter hub, the safety clip can disengage from the interlocking flange and encapsulate a tip portion of the needle member within the safety clip, thereby reducing the possibility of a needle stick injury upon withdrawal of the needle member from the catheter hub.

[0025] In some embodiments, the safety clip may include a bracket defining an opening for receiving the needle member. The first resilient arm may extend from one end of the bracket and may have a connecting portion for engaging at least one interlocking flange and at least one portion of the body portion and the needle member. The first resilient arm may include a first section and a section. The second resilient arm may extend from an opposing end of the bracket and may further include a connecting portion for engaging at least one interlocking flange and the needle member of the body portion. The second resilient arm may also include a first section and a second section, the first section having a larger dimension than the second section. The connecting portion of each of the first and second resilient arms may be configured to engage the interlocking flange and the body portion of the needle member when the needle member extends through the catheter hub on its way to puncture the patient's blood vessel. The connecting portion may disengage from the interlocking flange and the body of the needle member when the needle member is withdrawn from the proximal end of the catheter hub.

[0026] In some embodiments, the connecting portion of each of the first and second resilient arms includes a curved protrusion at one end. The curved protrusion can be configured to engage at least one interlocking flange and the curved lip segment of the body portion. The curved lip segment can extend inwardly toward the bracket member and can be configured to engage the needle member. The curved lip can be configured to encapsulate a tip portion of the needle member within the safety clip when the needle member is withdrawn from the proximal end of the catheter hub.

[0027] In some embodiments, the curved protrusion includes a projection extending toward the bracket. The projection, together with the second portions of the first and second resilient arms, can define a seat that can be configured to receive and seat a tip portion of the needle member, thereby preventing displacement of the needle member during withdrawal from the catheter hub.

[0028] In some embodiments, the first resilient arm can be longer than the second resilient arm.

[0029] In some embodiments, at least one of the bracket, the first resilient arm, and / or the second resilient arm can define at least one rib member for reinforcement.

[0030] In some embodiments, the rib members can be disposed on the second sections of the first and second resilient arms to reinforce the first and second resilient arms.

[0031] In some embodiments, each of the at least one interlocking flanges of the body portion extends radially inward to ensure engagement with the safety clip in its biased configuration such that the safety clip is retained within the needle guard assembly.

[0032] In some embodiments, the needle can include a protrusion proximal to its distal end, which can be configured to engage the bracket during withdrawal of the needle from the proximal end of the catheter tube, thereby preventing release of the needle from the needle guard assembly.

[0033] Other features and aspects of the present disclosure will become apparent from the following description and the accompanying drawings. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a perspective view of an example of an venous cannula apparatus according to an embodiment of the present disclosure. [Figure 2A] 2 is a cross-sectional view of the venous cannula apparatus of FIG. 1 showing a catheter assembly coupled to a needle guard assembly. [Figure 2B] 2 is a cross-sectional view of the intravenous cannula apparatus of FIG. 1 showing the catheter assembly separated from the needle guard assembly. [Figure 3A] 1 is a cross-sectional view of an example of a safety release component coupled to a needle guard assembly according to an embodiment of the present disclosure. [Figure 3B] FIG. 3B is a perspective view of the safety release component shown in FIG. 3A. [Figure 3C] FIG. 3B is another cross-sectional view of the safety release component shown in FIG. 3A. [Figure 3D] 13A-13C are cross-sectional views of an example of a configuration of a safety release component where the distal tip of a needle is enclosed within a needle safety component. [Figure 4A] FIG. 13 is a cross-sectional view of an example of another venous cannula device according to an embodiment of the present disclosure. [Figure 4B] 4B is an enlarged cross-sectional view of a portion of the venous cannula device of FIG. 4A showing a safety release component coupled to a needle guard assembly according to an embodiment of the present disclosure. FIG. [Diagram 5] 1 is a cross-sectional view of an example of a needle guard assembly according to an embodiment of the present disclosure. [Figure 6A]6 is a progressive snapshot of a portion of the needle guard assembly shown in FIG. 5 as the configuration of the needle guard assembly moves from an injecting state to a shielding state. [Figure 6B] 6 is a progressive snapshot of a portion of the needle guard assembly shown in FIG. 5 as the configuration of the needle guard assembly moves from an injecting state to a shielding state. [Figure 6C] 6 is a progressive snapshot of a portion of the needle guard assembly shown in FIG. 5 as the configuration of the needle guard assembly moves from an injecting state to a shielding state. [Figure 6D] 6 is a progressive snapshot of a portion of the needle guard assembly shown in FIG. 5 as the configuration of the needle guard assembly moves from an injecting state to a shielding state. [Figure 6E] 6 is a progressive snapshot of a portion of the needle guard assembly shown in FIG. 5 as the configuration of the needle guard assembly moves from an injecting state to a shielding state. [Figure 7] 1 is a cross-sectional view of an example of a duckbill component configured to releasably couple a catheter assembly to a needle guard assembly according to an embodiment of the present disclosure. [Figure 8] 1 is a cross-sectional view of another example of a venous cannula apparatus according to an embodiment of the present disclosure. [Figure 9] 9 is a perspective view of a safety clip disposed within a needle guard assembly of the cannula apparatus shown in FIG. 8 in accordance with an embodiment of the present disclosure. [Figure 10] 9 is a cross-sectional view of the cannula apparatus shown in FIG. 8 when the needle member is withdrawn from the catheter hub in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Non-limiting embodiments of the present disclosure are provided herein. References to specific embodiments and features are detailed throughout the present disclosure, and examples are shown in the accompanying drawings. Reference numbers are included in the drawings to refer to the same or corresponding parts. Although references to various elements described herein are made collectively or individually when there may be two or more elements of the same type, such references are merely exemplary in nature. Any reference to an element in the singular form may also be interpreted as relating to the plural form, and vice versa, without limiting the scope of the present disclosure to the exact number or type of such elements, unless expressly stated in the text.

[0036] As used herein, the term "proximal end" can refer to the end of the disclosed device that is closer to the operator. As used herein, the term "distal end" can refer to the end opposite the "proximal end" that is closer to the patient being treated by the disclosed device. Thus, the terms "distal" or "distal end" and "proximal" or "proximal end" can refer to the direction or end that is further from and closer to the operator who inserts the catheter into the patient's body, respectively.

[0037] As used herein, the terms "operator" and "user" may be used interchangeably and may include, but are not limited to, medical professionals and personnel such as nurses or paramedical staff who may work under the direction and supervision of a physician, physician, and / or surgeon and may also be considered users or operators according to the embodiments described herein.

[0038] The term "connected" or "fixedly connected" as used in this disclosure may refer to components that may be fixedly attached to one another, which may be permanent in the sense that disconnection requires specialized tools and / or excessive physical force. "Releasably connected" or "coupled" may refer to components that may be temporarily connected and disconnected through one or more device functions. The term "slidably connected" may refer to components assembled together such that any one or more of the components may slide relative to the other components during use of the device. The contact surfaces of the components may allow such sliding. The term "disposed" as used herein may mean that a component or elements of an apparatus may be connected to another element such that a workable assembly is formed without interfering with the functionality of each individual element. The term "comprising" means that a given apparatus or components thereof may include additional components other than those expressly identified herein.

[0039] This disclosure includes numerical terms and phrases such as "one or more," "at least," "a," and "an." The specific numbers associated with such terms are not to be construed as limiting.

[0040] Terms defining shapes, such as "convex," "frustoconical," "flat," "substantially flat," "cylindrical," "tubular," "elongated," "circular," "converging," "diverging," "tapered," or "expanding," should not be construed as limiting. Those skilled in the art will recognize that these shapes, whether modified by terms such as "generally" or "substantially," allow for some variations, such as "circular" shapes, but do not have to meet the theoretical definition of "circular" to be circular within the meaning of the term as used herein. In certain embodiments, other shapes may be possible. Thus, those skilled in the art may develop other shapes or combinations of shapes that maintain the operability of the disclosed device. Any such variations may still be encompassed within the present disclosure without departing from the invention.

[0041] The terminology used in this disclosure includes the words specifically mentioned, their derivatives, and words of similar meaning. The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed. These embodiments have been chosen and described in order to best explain the principles of the invention, its applications, its practical use, and to enable those skilled in the art to best utilize and develop the invention.

[0042] 1 and 2 show perspective and cross-sectional views, respectively, of a cannula 100 according to an embodiment of the present disclosure. The illustrated cannula 100 is a medical device that can be used to administer fluid medications via intravenous therapy and / or remove bodily fluids, such as blood, from a patient for subsequent analysis. The specific types of cannula devices disclosed herein may vary as may the associated tasks performed therewith. In the illustrated illustration, the cannula 100 is an intravenous cannula device. The term "intravenous cannula" is used interchangeably with "cannula" herein for brevity.

[0043] 1 and 2 includes a catheter assembly 102 configured to reversibly mate with a needle hub, chamber, or guard assembly 104. The snapshot shown in FIG. 1 shows the catheter assembly 102 mated with the needle guard assembly 104.

[0044] The catheter assembly 102 includes a body member 103 that surrounds a catheter hub 105, which can be secured or coupled to a catheter tube 106. A needle 108 is shown within the catheter tube 106, which can be made of a flexible or soft material, non-limiting examples of which can include a plastic or polymeric composition. In an embodiment, the body member 103 and other components of the catheter assembly 102, such as the catheter hub 105, can be made of a biocompatible material that can be substantially rigid.

[0045] The cannula 100 is configured to allow the catheter assembly 102 to be decoupled from the needle guard assembly 104 after the needle 108 has punctured a target vessel and been retracted proximally through the catheter assembly 102, thereby leaving at least a portion of the distal portion 109 of the catheter assembly 102 within the vessel to facilitate delivery and / or withdrawal of various agents and / or bodily fluids. Embodiments of the cannula 100 can also be configured to prevent inadvertent needle stick injuries by fully enclosing the needle 108 (including its distal tip) within the needle guard assembly 104 after puncturing the target vessel.

[0046] The catheter tube 106 defines an elongated longitudinal bore through which the needle 108 can slide. The catheter tube 106 can be secured to the catheter assembly 102 by a number of methods, including but not limited to press fit, adhesive bonding, or any other suitable method that may be particularly applicable to the catheter hub 105. In some examples, the catheter tube 106 may be integrally formed with the catheter assembly 102. A thumb grip 110 can also be included for grasping and manipulating the cannula 100 to reposition the needle tube 106 during insertion and retraction of the needle 108.

[0047] In the illustrated embodiment, the body member 103 is a Y-shaped body member, however, this example is not limiting as other shapes and sizes of the body member 103 may be compatible with one or more embodiments disclosed herein. The illustrated Y-shaped body member 103 has a cylindrical body portion 112 along with the catheter hub 105 and a tangential portion 114 connected to the cylindrical body portion 112. Both the cylindrical body portion 112 and the tangential portion 114 may be integrally formed or manufactured. In another embodiment, the tangential portion 114 may be releasably connected to the cylindrical body portion 112. The body member 103 may be made of medical grade plastics known in the art. The tangential portion 114 may be connected to a tube 116 for administering a fluid as described above.

[0048] One end 118 of the tube 116 may be connected to the tangential portion 114 of the body member 118, and a second end 120 of the tube 116 may be connected to a flashback chamber 122. The flashback chamber 122 may include a female luer 124, a flow control hub 126, and a filter 128. Blood flow from the patient into the flashback chamber 122 confirms that the needle 108 has successfully punctured the vein or artery.

[0049] The tube 116 may further include a slide clamp 130 for positioning or connecting the tube 116 to a stand or pole. One or more wing members 131 may also be coupled or integrally formed with the body member 103. The wing members 131 may help connect or secure the catheter assembly 102 to a patient's clothing or body part, such as a hand or arm, after puncturing a target blood vessel. In various embodiments, any luer lock member having a standard size or ISO standard that fits the catheter assembly 102 may be used. For example, ISO standards ISO-80369-20 and ISO-80369-7 may be used for luer lock members having a generic taper of 6%. In additional embodiments, the luer lock member 124 may have other configurations or shapes, such as a luer slip.

[0050] The needle guard assembly 104 may include an elongated tubular member 132 at least partially surrounded by a gripping member or surface 133. The elongated tubular member 132 may include a needle hub 134 with a needle holder 136. The needle holder 136 may be disposed inside the elongated tubular member 132 and may connect a distal portion 137 of the needle holder 136 to the needle 108. The elongated tubular member 132 may be sized to accommodate the entire length of the needle 108 such that retraction of the needle 108 into the elongated tubular member 132 surrounds and shields the distal tip of the needle 108. The shape of the elongated tubular member 132 may vary and may be cylindrical, rectangular, or any other suitable configuration.

[0051] The needle guard assembly 104 also includes a safety release component 138 secured to a distal end 140 of the elongated tubular member 132. The safety release component 138 may be releasably coupled to the body member 103 of the catheter assembly 102 such that after the catheter assembly 102 is coupled to the needle guard assembly 104, the safety release component 138 is disposed between the proximal end 107 of the body member 103 and the distal end 140 of the elongated tubular member 132.

[0052] 2B provides a snapshot cross-sectional view of the cannula 100 when the catheter assembly 102 is not coupled with the needle guard assembly 104. As shown, the safety release component 138 is separated from the body member 103 of the catheter assembly 102 and the needle 108 is enclosed within the needle guard assembly 104.

[0053] As shown in conjunction with FIG. 3A, to facilitate coupling of the catheter assembly 102 and the needle guard assembly 104, the body member 103 includes a proximal cylindrical portion 142 defining an axial bore 143 and an annular groove 144 on its inner surface 146. The annular groove 144 of the proximal cylindrical portion 142 is configured to be complementary to, and thus engage, one or more locking elements 148a,b of the safety release component 138. The locking elements 148a,b can be inserted into the annular groove 144 only when the safety release component 138 is inserted into the axial bore 143 of the proximal cylindrical portion 142 and the needle 108 is inserted into the safety release component 138. By tightly mating with the body member 103 upon insertion of the needle 108 therethrough, the safety release component 138 increases the catheter separation force, thereby reducing the likelihood that the catheter assembly 102 will separate from the needle guard assembly 104 while the needle 108 remains wholly or partially disposed within the catheter assembly 102. Similarly, retracting the needle 108 proximally through the catheter assembly 102, safety release component 138 and into the needle guard assembly 104 significantly reduces the catheter release force, resulting in a relatively small amount of force being required to remove the needle guard assembly 104 from the catheter assembly 102. This reduced catheter release force allows for easier removal of the needle guard assembly 104 by the operator and reduces the possibility of disturbing the placement of the catheter assembly 102 within the patient. In the illustrated embodiment, the two locking elements 148a,b are solid and spherical, although embodiments are not limited to solid and spherical locking elements. Notches, ridges or protrusions may be used in place of grooves.

[0054] After passing through the safety release mechanism 138 and the proximal cylindrical portion 142, the needle 108 extends distally through a rubber valve member 150 disposed within the body member 103 and continues through the catheter hub 105 and catheter tube 106 on its way to puncture the target blood vessel.

[0055] In embodiments, a distal portion of the needle guard assembly 104, e.g., the safety release component 138, and / or a proximal portion of the catheter assembly 102, e.g., the proximal cylindrical portion 142, may include one or more radial seals configured to prevent the inflow and outflow of fluid through or around the cannula 100.

[0056] Thus, the cannula 100 can include a needlestick prevention mechanism configured to enclose the distal tip of the needle 108 within the needle guard assembly 104 before and after insertion of the needle 108 into a patient. The safety release component 138 is one example of a component of a needlestick safety device implemented in accordance with embodiments disclosed herein. The safety release component 138 can include two movable locking elements 148a,b configured to control coupling of the catheter assembly 102 to the needle guard assembly 104 based on whether the needle 108 is present within either or both components.

[0057] 3A illustrates an enlarged cross-sectional view of safety release component 138 and surrounding mechanism in an engaged and locked state with proximal cylindrical portion 142 of body member 103. As shown, locking elements 148a,b are each engaged or locked with a portion of annular groove 144 defined by inner surface 146 of proximal cylindrical portion 142 of body member 103. In this engaged state, safety release component 138 is secured to distal end 192 of elongate tubular member 132 and releasably connected to proximal cylindrical portion 142 of body member 103.

[0058] 3B is a perspective view of a safety release component 138 according to an embodiment disclosed herein. The safety release component 138 includes a first proximal end 194 having a circular base 196 that can be secured to the distal end 192 of the elongated tubular member 132. In some examples, the circular base 196 can be press fit into the elongated tubular member 132, thereby making the two components integral. The safety release component 138 can also include a tubular portion 198 that defines an axial bore 200 dimensioned to accommodate passage of the needle 108.

[0059] 3C and 3D show safety release component 138 in a disengaged or unlocked state relative to body member 103 at the time of a snapshot in which needle 108 is retracted proximally or extended distally such that the needle tip is momentarily positioned within safety release component 138 and the tip is fully enclosed. Although needle tip 208 has not yet been fully retracted into needle guard assembly 104, fully separating safety release component 138 (and needle guard assembly 104) from body member 103 will position needle tip 208 in a safe, non-exposed area within safety release component 138 so as not to cause an accidental puncture injury. In the disengaged or unlocked state, the safety release component 138 may not be coupled to the body member 103, or at least may not be locked to the body member 103, but may be locked in the process of being separated from the body member, such that the safety release component 138 and the needle guard assembly 104 to which it is attached may be easily separated in unison from the catheter assembly 102 by applying a small amount of tension. As shown, the safety release component 138 may include one or more grooves 202a,b defined by the outer surface 204 of the tubular portion 198. Each of the grooves 202a,b is dimensioned to receive one of the locking elements 148a,b. The solid spherical locking element may be in the form of a stainless steel ball, although the disclosed embodiments are not limited thereto. The locking element may be any suitable shape, including, but not limited to, spherical, generally spherical, spheroidal, cylindrical (with or without tabs or other elements to retain the locking element in the grooves 202a,b), conical, and the like. The locking element may be separate from the groove and / or may float within the groove and / or may be connected to the groove, such as in a groove-tethered configuration, or may be integral with the groove.

[0060] The diameter of each groove 202a,b may be substantially the same as or slightly larger than the diameter of each corresponding locking element 148a,b. The size of each groove 202a,b facilitates smooth movement of the locking elements 148a,b proximally through the safety release component 138 radially outwardly away from the axial bore 200 as the needle 108 passes through the bore 200 in response to puncture of a vein or artery, and radially inwardly after subsequent withdrawal of the needle 108 from the patient.

[0061] The locking elements 148a,b of the safety release component 138 are configured to engage with the annular groove 144 of the body member 103, thereby forming a locked, close-fitting engagement between the elongated tubular member 132 of the needle guard assembly 104 and the catheter assembly 102 as the needle 108 passes through the safety release component 138 to puncture a patient's vein or artery. The needle 108 thus displaces the locking elements 148a,b away from the axial bore 200 and into the inner groove 144 to lock the catheter assembly 102 to the needle guard assembly 104. FIG. 3D illustrates that after the needle 108 is withdrawn from the patient, through the catheter assembly 102 and proximal to the distal end 206 of the needle guard assembly 104, the distal tip 208 of the needle 108 can be simply nested within the safety release component 138 (and thereafter the needle guard assembly 104), at which point the locking engagement between the body member 103 and the needle guard assembly 104 can be released. Disengagement occurs because the locking elements 148a,b can be displaced inwardly from the annular groove 144 of the proximal cylindrical portion 142 of the body member 103 after needle retraction, thereby releasing the locking engagement between the elongated tubular member 132 and the catheter assembly 102. Separation of the safety release component 138 from the catheter assembly 102 after nesting of the needle tip 208 within the safety release component 138 (for a longer period within the needle guard assembly 104) allows the needle to be withdrawn from the patient and removed from the catheter assembly 102 only when the distal tip 208 of the needle 108 is hidden, thereby reducing the possibility of needle stick injuries.

[0062] 2 and 3A-3D show an embodiment of cannula 100 having two movable locking elements 148a,b, additional examples may include more or less than two locking elements. As shown in FIG. 4A, an alternative embodiment of cannula 100' may feature safety release component 138' having only one locking element 148a'. FIG. 4B provides an enlarged view of cannula 100' at A'. Similar to cannula 100, cannula 100' includes a body member 103' having a proximal cylindrical portion 142' defining an annular groove 144' on an inner surface 146' thereof. Annular groove 144' of proximal cylindrical portion 142' is configured to be complementary to, and thus engage, movable locking element 148a' of safety release component 138'. The locking element 148a' can be inserted into the annular groove 144' only when the safety release component 138' is inserted into the axial bore 143' of the proximal cylindrical portion 142' and the needle 108' is inserted into the safety release component 138'.

[0063] The cannula embodiments described herein may also include mechanisms to ensure safe and reliable locking and unlocking of the needle guard assembly 104 (or 104') in a manner that further reduces the possibility of needle stick injuries. FIG. 5 is a cross-sectional view of one example of a portion of a needle guard assembly 104 configured in this manner. As shown, the interior of the needle guard assembly 104 may include a longitudinal notch 210 that defines a proximal receiving site 212. The notch 210 may further define a U-shaped slot detent cutout or notch 214 that defines a pair of fingers 216. The fingers 216 together define a narrow slot 218. The fingers 216 may be configured to be biased away from one another to widen the slot 218 in response to locking the needle guard assembly 104.

[0064] 2A, the needle guard assembly 104 can be configured to have an injection position in which the gripping member or surface 133 extends distally such that the needle 108 extends beyond the distal end 140 of the needle guard assembly 104, and a shielded position in which the distal tip of the needle 108 is disposed proximal to the distal end 140 and nested within the needle guard assembly 104. To move the needle hub 134 from the injection position to the shielded position, the guard assembly gripping member or surface 133 can be moved proximally such that a protrusion or rib 220, also included within the needle guard assembly 104, moves proximally through a longitudinal notch 210.

[0065] The proximal end of the rib 220 may define a ramp or cam surface 222. At rest, i.e., before the rib 220 passes therethrough, the slot 218 defined by the fingers 216 may be narrower than the width or thickness of the rib 220. As the needle hub 134 moves proximally toward the blocked position, the cam surface 222 of the rib 220 engages the fingers 216 and pushes them apart, thereby spacing the slot 218 apart to allow the rib 220 to pass therethrough. The proximal movement of the rib 220 through the longitudinal notch 210 and over the fingers 216 is shown progressively in FIGS. 6A, 6B, 6C, and 6D.

[0066] As the fingers 216 are biased apart, the needle hub 134 enters a locked phase in which the force generated by the camming action of the cam surfaces 222 against the fingers 216 exerts increased resistance to movement of the needle hub 134. Entry into the locked phase is shown in Figure 6B and passage through the locked phase is shown in Figure 6C.

[0067] After the fingers 216 are biased apart as far as necessary for the ribs 220 to enter the slots 218, the total force acting against the movement of the ribs 220 is exerted by the sliding action of the fingers 216 against the ribs 220. This force decreases as the needle hub 134, and therefore the ribs 220, continue to move proximally toward the closed state, as shown in Figures 6D and 6E.

[0068] Continued proximal movement of needle hub 134 moves rib gap 224 past the proximal ends of fingers 216, thereby allowing fingers 216 to snap back to their original, unbent state with the ends of fingers 216 nested within rib gap 224. This configuration defines a locked, blocked state in which needle 108 cannot be pushed distally without the application of a large external force in the distal direction. To prevent further proximal movement of needle hub 134 relative to elongate tubular member 132, cam surface 222 may extend to and contact the proximal end of receiving site 212.

[0069] In some examples, the cannula 100 can additionally or alternatively include a duckbill release mechanism at the distal end 140 of the needle guard assembly 104, an example of which is shown in FIG. 7. As shown, the duckbill release mechanism can include a pair of cooperating members, e.g., arms, each extending distally from the distal end 140 of the needle guard assembly 104. The arms can be included in place of the movable locking elements 148a,b of the safety release component 138 disclosed herein. Similar to the safety release component 138, the arms can be dimensioned to fit within the proximal cylindrical portion 142 of the body member 103. The force applied during entry into the lock activation stage described in connection with FIGS. 6A-6D can be applied while the duckbill release mechanism secures the needle guard assembly 104 to the catheter assembly 102. The safety release component 138 and the duckbill release mechanism can be included in separate embodiments such that the two release mechanisms are not included in the same device.

[0070] The cooperating arms can define a passage therebetween configured to slidably receive the needle 108. One or both of the members can have a retaining portion, such as a radially outwardly projecting detent and / or a radially inwardly extending recess, configured to mate with a complementary feature on the body member 103, which can be defined by the inner surface 146 of the proximal cylindrical portion 142. The inclusion of a duckbill feature can ensure a strong coupling between the catheter assembly 102 and the needle guard assembly 104 when the needle 108 is inserted therethrough. The duckbill feature can facilitate easy separation of the catheter assembly 102 from the needle guard assembly 104 when the needle 108 is not present.

[0071] Referring again to FIG. 7, an example of a duckbill mechanism included in some embodiments can include a distal cap 226 comprised of a nose 228 configured to be removably coupled with the proximal cylindrical portion 142 of the body member 103 such that the distal cap 226 abuts the inner surface 146 of the proximal cylindrical portion 142. A pair of distally extending arms 230, 232 defining a split cylinder are also dimensioned to fit within the axial bore 143 of the body member 103. The arms 230, 232 can be radially deflected toward one another when subjected to a compressive force, while in an uncompressed, relaxed state the arms can define a passageway 234 therebetween configured to slidably receive the needle 108. Alternatively, the arms 230, 232 can be biased inwardly toward one another and forced into a parallel configuration when the needle is between them. An end of one or each arm 230, 232 can include a retaining portion in the form of a protrusion or detent 236. The inclusion of one or more detents 236 defines one or more recesses 238 proximal thereto. The outer periphery 240 of the detents 236 may define an annular ring having a diameter at least slightly larger than the inner diameter of the proximal cylindrical portion 142 of the body member 103. In some examples, the detents 238 may be chamfered distally.

[0072] When the needle 108 is present in the passageway 234 between the arms 230, 232, compression of the arms 230, 232 is prevented such that release of the distal cap 226 from the axial bore 143 of the body member 103 requires significant force, thereby reducing the likelihood of the catheter assembly 102 separating from the needle guard assembly 104 while the needle 108 remains within the catheter assembly 102. Alternatively, when the arms are biased toward one another, retraction of the needle moves the arms away from the inner wall of the catheter hub and toward one another.

[0073] Embodiments of the disclosed device may include additional and / or alternative structures. As shown in Figures 8-10, for example, cannula 300 may include a safety clip 302 in addition to or instead of the ball release mechanism described above to prevent accidental needle sticks. Cannula 300 may include a needle guard assembly 304 having a body portion 306 connected to a body member 308 coupled with a catheter hub 309 of a catheter assembly such that a protrusion 310 on body portion 306 engages a recess 311 in body member 308. Body portion 306 of needle guard assembly 304 defines an inner bore 312 configured to receive safety clip 302. Safety clip 302 may be disposed within body portion 306 such that safety clip 302 engages at least one interlocking flange 314 defined in body portion 306. In its resting, biased configuration, safety clip 302 may allow a needle to extend through body portion 306 and body member 308. Upon withdrawal of the needle from the proximal end of the body member 308, the safety clip 302 can disengage from the interlocking flange 314 and enclose the tip portion 316 of the needle 318 within the body member 308, thereby preventing needle stick injuries during withdrawal of the needle 318 from the patient.

[0074] The needle hub 322 is in a close-fitting relationship with the body portion 306 and may be fixedly connected to the needle 318. In this manner, as the needle 318 is withdrawn from the needle hub 322, the needle hub 322 disengages from the body portion 306 and is withdrawn from the body member 308, and the needle hub 322 disengages from the body portion 306. Due to the configuration of the safety clip 302 within the body portion 306, the safety clip 302 is also disengaged from the body portion 306 and withdrawn along with the needle 318. Thus, the tip portion 316 of the needle 318 is not exposed to the user during withdrawal of the needle 318 from the patient. In some embodiments, the needle hub 322 may be provided with a thumb grip 324 to allow a user to grip the cannula 300 during use.

[0075] 9 is an enlarged perspective view of safety clip 302. Safety clip 302 is configured to block the entry of needle 318 into body member 308 of catheter assembly 302 and retain tip portion 316 of needle 318 therein when needle 318 is withdrawn from body member 308. Safety clip 302 includes a bracket 352 that defines an opening 354 for receiving needle 318. Opening 354 may be sized based on the diameter of needle 318 used with cannula 300. Opening 354 allows the needle to move proximally through safety clip 302 until opening 354 reaches one or more bumps, grooves, slots, bulges, crimps, flattened portions, and / or protrusions near the distal end of needle 318 that are larger than opening 354 such that safety clip 302 cannot slip off the distal end of needle 318. For example, needle 318 can define a crimp 355 near its distal tip 316. Crimp 355 of needle 318 can include a pair of generally opposed outwardly extending bulges 355a and a pair of generally opposed inwardly extending recesses 355b disposed generally perpendicular to bulges 355a. Bulges 355a define crimp 355 having a width W that is small enough to facilitate movement of needle 318 within cannula 300, but large enough to prevent the distal end of needle 318 from passing through opening 354.

[0076] The first resilient arm 356 extends from one end of the bracket 352 and has a first portion 358 and a second portion 360, and in some embodiments, the dimensions of the first portion 358 may be greater than the dimensions of the second portion 360. As an example, the first portion 358 may be wider than the second portion 360. Such a structure of the safety clip 302 allows for easy and inexpensive manufacture of the safety clip 302 while ensuring sufficient spring or bias spring force requirements. The first portion 358 can further match the dimensions of the bracket 352, thus ensuring uniformity of the structure that retains the structural rigidity of the safety clip 302 when subjected to deformation.

[0077] The second resilient arm 362 extends from the other end of the bracket 352 and has a first portion 364 and a second portion 366, where in some embodiments the first portion 364 may have a larger dimension than the second portion 366. As an example, the first portion 364 may be wider than the second portion 366. Such a structure of the safety clip 302 allows for easy and inexpensive manufacture of the safety clip 302 while ensuring sufficient spring or bias force requirements. The first portion 364 may further match the dimensions of the bracket 352, thus ensuring uniformity of structure that retains the structural rigidity of the safety clip 302 when subjected to deformation.

[0078] A connecting portion 368 is also preferably included in the second portion 360. The connecting portion 368 is configured to engage at least one interlocking flange 314 configured on the body portion 306 and the inner surface of the needle 318. The connecting portion 368 is configured to engage the interlocking flange 314 and the body 370 of the needle 318 to puncture a vein of a subject. The connecting portion 368 further disengages from the interlocking flange 314 and the body 370 of the needle 318 when the needle 318 is withdrawn from the proximal end 372 of the body member 308.

[0079] Connecting portion 368 includes a curved protrusion 374 at a forward end and a curved lip 376 at a rearward end. Curved protrusion 374 is configured to engage interlocking flange 314 of body portion 306 such that safety clip 302 is retained within body portion 306. Curved lip 376 at the rearward end extends inwardly toward bracket 352 and is configured to engage needle 318.

[0080] The curved protrusion 374 engages the interlocking flange 314 due to the bias of the first and second resilient arms 356, 362. The first and second resilient arms 356, 362 are biased or deflected by the insertion of the needle 318 into the body member 308. The insertion or presence of the needle 318 in the needle guard assembly 304 deflects the first and second resilient arms 356, 362 away from one another, thereby engaging the curved protrusion 374 into engagement with the interlocking flange 314. At the same time, the curved lip 376 engages the body 370 of the needle 318, thereby maintaining the biasing force and retaining the safety clip 302 within the body portion 306.

[0081] In some embodiments, the curved protrusions 374 of the first and second arms 356, 362 are outwardly extending protrusions configured to engage with the interlocking flanges 314 of the inwardly projecting body portion 306. Thus, the structure or shape or configuration of the curved protrusions 374 can be selected based on the structure of the interlocking flanges 314 to ensure an interlocking therebetween when the needle 318 is present within the body member 308.

[0082] In another embodiment, the curved lip 376 of the first and second arms 356, 362 may comprise an inwardly extending protrusion configured to engage the needle 318 when the needle 318 is present within the body member 308 and to enclose the tip portion 316 of the needle 318 within the safety clip 302 when the needle 318 is withdrawn from the body member 308. The curved lip 376 is thus configured to prevent the entry or re-entry of the needle 318 beyond the safety clip 302 when the needle 318 is withdrawn from the body member 308. Thus, the structure or shape or configuration of the curved lip 376 may be selected based on the configuration of the needle 318 or the location where the needle is inserted or withdrawn. As one non-limiting example, the curved protrusion 374 may be an inverted U-shaped member and the curved lip 376 may be a U-shaped member.

[0083] Additionally, the curved protrusions 374 of the first and second arms 356, 362 may include a protrusion 378 extending toward the bracket 352. The protrusions 378, together with a second portion of each arm, define a seat 380. The seat 380 is adapted to receive and seat the tip portion 316 of the needle 318 such that the tip portion 316 of the needle 318 is securely seated within the safety clip 302, thereby preventing displacement of the needle 318 during withdrawal from the body member 308 or disposal of the needle 318.

[0084] In one embodiment, the first resilient arm 356 is longer than the second resilient arm 362. Such a configuration of the arms 356, 362 may be provided to ensure that a sufficient biasing force is applied to the interlocking flange 314 during use, thereby ensuring that the safety clip 302 is adequately retained within the body portion 306. Also, the asymmetric lengths of the arms can ensure that the connecting portion 368 contacts the body of the needle 318 in the same plane. Such engagement can ensure uniform stress distribution on the needle 318, thereby preventing damage during assembly. In one embodiment, the needle 318 can be assembled to the body member 308 of the body portion 306 by first bending the arms 356, 362 and then inserting the needle 318 through the tubular sleeve.

[0085] Additionally, each of the bracket 352 and the first and second resilient arms 356, 362 may be defined by at least one rib member 382. The rib member 382 reinforces the safety clip 302 and improves its overall strength. As an example, the rib member 382 may extend around a surface of the bracket 352. The rib member 382 may also extend along a second portion of the first and second arms 356, 362, which essentially improves the strength of the second portion. The length of extension of the rib member 382 may be configured based on the strength or rigidity requirements of the safety clip 302. In one embodiment, the rib member 382 may be formed in the bracket 352 and / or the arms via conventional manufacturing techniques, such as stamping.

[0086] In one embodiment, the rib member 382 may be provided on the bracket 352 as reinforcement to prevent damage to the bracket 352 from protrusions contacting the needle 318 during removal of the needle 318. Such a structure ensures that the needle 318 is retained within the safety clip 302 upon withdrawal. In some embodiments, the rib member 382 may be made of a metal material, a plastic material, a composite material, or any other material that serves the purpose of providing reinforcement to the safety clip 302.

[0087] In one embodiment, the bracket 352 and the first and second arms 356, 362 may be made of a metallic material or any other material that serves the purpose of ensuring interlocking with the body portion 306 when the needle 318 is present within the body member 308, and enclosing the tip portion 316 when the needle 318 is withdrawn from the body member 308.

[0088] Additionally, once the tip portion 316 of the needle 318 is withdrawn from the proximal end 372, specifically past the connecting portion 368 of the arms 356, 362 of the safety clip 302, the biasing force acting on the arms 356, 362 due to contact with the needle 318 ceases. Thus, the arms retract to an unbiased configuration in which the curved lips 376 fully close the path for the tip portion 316 to move forward past the safety clip 302. Thus, the safety clip 302 retains the needle 318 upon withdrawal from the body member 308. In this scenario, the safety clip 302 may be withdrawn from the body portion 306 along with the needle 318 via the needle hub 322.

[0089] Because the tip portion 316 rests on a seat 380 configured on the safety pin 302, alignment of the needle 318 is maintained regardless of the needle 318 upon withdrawal. Thus, exposure of the tip portion 316 of the needle 318 is prevented, reducing the possibility of needle stick injuries. In an embodiment, the tip portion 316 may be selectively rested on either of the seats 380 configured on the first and second arms 356, 362.

[0090] The disclosed cannula devices can prevent the tip of the needle from contacting the user after the needle is withdrawn. For example, the disclosed needle safety components provide a safety mechanism in the form of one or more safety release components that shield the tip of the needle as it is withdrawn after puncturing a patient's blood vessel.

[0091] The disclosed locking elements, which in some examples may include a solid spherical ball, provide for selective disengagement of the catheter assembly from the needle guard assembly upon proximal retraction of the needle into the needle guard assembly, thereby generally preventing needle tip exposure and associated needle stick injuries.

[0092] The disclosed locking element, which includes a solid spherical ball, allows for easy removal of the needle by releasing the locking engagement between the catheter assembly and the needle guard assembly.

[0093] The embodiments described herein may also be configured with additional or alternative needle release and retraction mechanisms. For example, the disclosed cannula embodiments may include a coil spring biased to retract the needle proximally so that the needle is automatically retracted and enclosed within the needle guard assembly after and before deployment. The embodiments may also feature a push button mechanism configured to facilitate needle release and retraction and / or facilitate coupling and decoupling of the catheter assembly and the needle guard assembly. The embodiments may include a manually operable push button that, in some instances, extends outwardly from the needle guard assembly, protrudes from a surface of the cannula, or is accessible at a surface of the cannula. Actuation of the push button may be necessary to overcome a spring force within the needle guard assembly that biases the needle in a proximal direction. Outward displacement of the push button may allow an internal component of the needle guard assembly, such as the needle hub, to move distally along with the needle attached thereto. An example of a spring-loaded, push-button actuated cannula configuration compatible with one or more of the disclosed embodiments is described in U.S. Pat. No. 4,747,831, the entire contents of which are incorporated herein by reference.

[0094] Although aspects of the present invention have been particularly shown and described with reference to the above embodiments, it will be understood by those skilled in the art that various additional embodiments may be contemplated by modification of the disclosed apparatus without departing from the scope of what is disclosed. Such embodiments are to be understood to be within the scope of the present invention as determined based on the claims and any equivalents thereof.

Claims

1. 1. An intravenous cannula apparatus comprising: a catheter assembly comprising a catheter hub coupled to a catheter body member having a distal end connected to a proximal end of a catheter tube, the inner surface of a proximal portion of the catheter body member comprising an annular groove; a needle guard assembly configured to mate with a proximal end of the catheter assembly, An elongated tubular member; a needle hub including a needle holder disposed within the elongated tubular member, a distal end of the needle holder being connected to a needle; a safety release component secured to a distal end of the elongate tubular member, the safety release component comprising a body and one or more movable locking elements configured to releasably couple with the catheter body member, each of the movable locking elements being dimensioned to fit into one of one or more complementary grooves defined by an exterior surface of the body; a needle guard assembly including: Equipped with each of the one or more movable locking elements is configured to engage the annular groove of the catheter body member by moving radially outward from one of the complementary grooves, thereby coupling the elongated tubular member of the needle guard assembly to the catheter assembly when the needle passes through the safety release component pursuant to puncturing a patient's blood vessel.

2. the body of the safety release component further comprises a longitudinal bore through which the needle passes; 2. The venous cannula apparatus of claim 1.

3. the one or more movable locking elements are spherical; 2. The venous cannula apparatus of claim 1.

4. the one or more movable locking elements are made of stainless steel; 4. The venous cannula apparatus of claim 3.

5. the safety release component comprises a circular base secured to a distal end of the elongate tubular member; 2. The venous cannula apparatus of claim 1.

6. the safety release component includes a tubular portion extending from the circular base and defining an axial bore configured to accommodate passage of the needle; 6. The venous cannula apparatus of claim 5.

7. each of the one of the one or more complementary grooves extending toward the axial bore of the tubular portion of the safety release component; 7. The venous cannula apparatus of claim 6.

8. each of the one or more movable locking elements is configured to receive within one of one or more complementary grooves following withdrawal of the needle from the longitudinal bore.

8. The venous cannula apparatus of claim 7.

9. 1. An intravenous cannula apparatus comprising: a catheter hub coupled to a catheter body member, the catheter body member having a proximal end, a distal end, and a coaxial recess extending from the proximal end to the distal end; a needle guard assembly configured to couple to the proximal end of the catheter body member, An elongated tubular member; a needle hub comprising a needle holder disposed within the elongated tubular member, a distal end of the needle holder being connected to the needle; a safety release component secured to a distal end of the elongate tubular member, the safety release component comprising a body and one or more movable locking elements configured to releasably couple to the catheter body member; a needle guard assembly including Equipped with The one or more movable locking elements are configured to engage the proximal end of the catheter body member, thereby coupling the elongated tubular member of the needle guard assembly to the catheter body member when the needle passes through the safety release component pursuant to puncturing a patient's blood vessel.

10. the catheter body member comprises a Y-shaped body including a tangential segment extending away from the coaxial recess between the proximal and distal ends of the catheter body member.

10. The venous cannula apparatus of claim 9.

11. 1. A safety intravenous cannula comprising: a catheter assembly including a catheter hub having a distal end connected to the proximal end of the catheter tube, and a body member adapted to receive the catheter hub at its distal end; an elongated tubular member disposed at a proximal end of the catheter assembly; a needle hub including a needle holder disposed inside the elongated tubular member, a distal end of the needle holder being connected to a needle; a safety device fixedly connected to a distal end of the elongated tubular member and releasably connected to the body member of the catheter assembly; Safety intravenous cannula.

12. The body member has an annular groove on an inner surface thereof, and the safety device includes one or more locking elements.

12. The safety venous cannula of claim 11.

13. the one or more locking elements of the safety device are adapted to engage with the annular groove of the body member, thereby forming a locking engagement and close fitting relationship between the elongated tubular member and the catheter assembly when the needle is passed through the safety device to puncture a patient's vein.

13. The safety venous cannula of claim 12.

14. when the needle is retracted from the catheter assembly after puncturing the patient's vein, the body member disengages from the elongate tubular member by disengaging the locking element from the annular groove.

14. The safety venous cannula of claim 13.

15. the safety device includes a groove on an outer surface of the safety device to receive one or more locking elements; 12. The safety venous cannula of claim 11.

16. the one or more locking elements are solid spherical elements made of stainless steel material; 16. The safety venous cannula of claim 15.

17. the groove of the safety device has a diameter equal to or greater than the diameter of the solid spherical element; 17. The safety venous cannula of claim 16.

18. a first end of the safety device having a circular base defining a central bore and fixedly connected to the distal end of the elongate tubular member; 18. The safety venous cannula of claim 17.

19. the safety device comprises a tubular portion extending from the circular base and including an axial bore extending from the central aperture to define the passageway for the needle; 20. The safety venous cannula of claim 18.

20. the groove in the outer surface of the tubular portion of the safety device extends toward the axial bore of the safety device; 20. The safety venous cannula of claim 19.

21. the solid spherical element of the safety device is adapted to move outwardly into engagement with the annular groove of the body member, thereby forming the locking engagement and the close fitting relationship between the elongated tubular member and the catheter assembly when the needle is passed through the safety device to puncture the vein of the patient.

21. The safety venous cannula of claim 20.

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