Description:FORM 2

The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2003

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“IV CANNULA WITH ADVANCED TIP PROTECTOR
ASSEMBLY”

APPLICANT:

Name: Lars Medicare Private Limited

Nationality: Indian

Address: Killa 16 &17, Village Sultanpur, Bahalgarh Chowk, Sonipat, Haryana, India – 131021.

The following specification particularly describes the invention and the manner in which it is to be performed: -
FIELD OF INVENTION
[0001] The present application is a patent of addition of Indian Complete Application 201811012276 filed on 25th March 2019, which further claims priority from Indian Provisional Application 201811012276 filed on 31st March 2018, the disclosures of which are incorporated herein. The present invention relates to an intravenous cannula with a tip protector assembly and more particularly to a safety intravenous cannula having an embodiment for protection against any kind of accidental injury due to the sticking of the sharp tip of the needle.
BACKGROUND
[0002] IV catheters are primarily used to infuse fluids, sometimes containing medications, directly into patient’s vascular system or to withdraw blood from a patient. A hand held placement device that includes a sharp tip needle is used to insert the catheter into a patient’s vein. Such a device generally consists of hollow-bore needle and an over-the-needle plastic/silicon or like materials tubing used to access the lumen of a blood vessel of a patient.
[0003] The catheter is inserted at a shallow angle through the patient’s skin into a peripheral blood vessel by a health worker using the hand held placement device. The needle is then withdrawn leaving the catheter in the place either for direct hook up for transfusion of fluid or for the later use.
[0004] Once proper placement is confirmed the health worker applies pressure to the blood vessel by pressing down on the patient’s skin near the tip of the needle and catheter. During this process of placing the IV catheter in the vascular system of the patient, the hollow- bore needle becomes blood contaminated and when the blood vessel is accessed, the needle become blood filled.
[0005] In recent years, there has been great concern over the inadvertent injuries caused by the “blood contaminated needles” to the medical professionals. This put the medical professionals at great risk of being infected by the diseases which can be transmitted from infected person to the injured person through the contaminated needle. Thus, it is desirable to avoid contact of the patient’s body fluid with the medical professionals by protecting the needle tip/bevel. This very danger to the safety of the medical personnel/health care worker and the others has caused an impetus for the invention of a safer intravenous Cannula in which the occurrence of such inadvertent injury due to needle stick will be prevented.
[0006] Various attempts have been made since long back from time to time to prevent the needle stick injuries through various kinds of assemblies of devices. However, some of them are far expensive, complex due to their large numbers of components; some despite solving the problems do cover large space. The prior art safety devices all exhibit one or more drawbacks that have thereby far limited their usefulness and full acceptance by healthcare workers.
[0007] The invention disclosed in US4026287 provides for retraction of the used needle into a cavity in a unitary, sturdy structure. However, it requires screwing the syringe plunger into the back of the needle flange after use, to destroy a fragile seal around the flange and then retract the needle. There are also chances of inadvertent introduction of fingertips into the syringe barrel. Even the plunger could remain in place, held only by detents at the rear of the barrel.
[0008] In US 4935012 A, a safety device comprises an elongated protective sleeve supported by front and rear bearing members for sliding movement about a medical needle and its associated support structure such as a support hub or barrel. The protective sleeve is slidable in a stable manner from a first position with the pointed end of the needle safely retracted within and shielded by the front bearing member to a second position with the needle projecting through and beyond the front bearing member for normal use. After use, the sleeve is slidable to a third position derailing the pointed needle end from the front bearing member, and exposing a visual indicator to indicate that the needle has been used. Closure flaps associated with the front bearing member, and thereby prevent accidental or unauthorized needle reuse. Dent members interacting between the rear bearing member and the needle support structure releasably lock the protective sleeve in the various positions.
[0009] That the above said invention has its own limitations. The said invention provides slidable sleeve for the protection of the needle which requires mechanical movement whereas the present invention provide means for automatic protection. The working mechanism for both of the invention are totally different. Inadvertent skipping of mechanically moving the protection sleeve over the needle after the use may lead to the needle stick injury. Further the slidable sleeve is not provided with any mechanism to prevent the needle to come out of it if both are pulled in opposite directions. Also said invention does not propose resilient material to successfully prevent the forward movement of needle if push force is applied from the rear side of the needle. The present invention overcomes the above mentioned limitations of the said invention by providing automatic means for the protection against the needle stick injury. In the present invention a tip protector assembly is used within the IV Cannula assembly which is economical because of its simple yet highly workable structure and it successfully protects the tip of the completely retracted needles ready for disposal.

SUMMARY
[0010] Certain terminology is used herein for the convenience only and is not to be taken as a limitation to the present invention. The term “distal” and “proximal” refer, respectively to directions farther away and closer to from, respectively, to the person administering the IV Cannula into the body of the patient. The terminology includes the word specifically mentioned, derivatives thereof and words of similar import.
[0011] The present invention envisages an intravenous cannula with safety tip protector assembly including a needle, an intravenous delivery catheter assembly removably located coaxially over the needle such that the needle can be withdrawn from the assembly after successful placement of the delivery end of the catheter tube in patient vein. The present invention includes a safety tip protector assembly which is coaxially and slidably arranged over the needle and removably attached to the proximal portion of the catheter assembly and adopted to protectively cover the needle tip and having mechanism for obstructing the needle tip from emerging out from distal end of safety tip protector assembly once retracted and activating the said mechanism. The safety tip protector assembly is also having mechanisms to engage a bulge present at the distal portion of the needle near the bevel and thereby preventing the portion of the needle from bulge till the tip from emerging out from the proximal end of the safety tip protector assembly.
[0012] The said safety tip protector assembly is made up of non reactive metal preferably stainless steel and comprises essentially of a retaining strip acting as a base and is present with a needle through bore, a stem which is extension of one side of the base in distal direction and further bending in a direction parallel to the base portion and is present with a needle through bore upon said parallel portion in such a manner that the said needle through bores and provides a passage for the needle. The needle through bore of the retaining strip is having a profile larger than the principle profile of the needle but lesser than the outer profile of the bulge/ dent present on the needle. The needle through bore present at the said parallel portion is having a profile slightly larger than the outer profile of the bulge and allows the bulge to pass through it. The stem is having length lesser than the length of the needle portion between the bulge and the tip.
[0013] The safety tip protector assembly is also having a first arm and a second arm which are extension of the sides of the base adjacent to the side attached with stem in distal direction. A plurality of claws is at the distal ends of the first arm and the second arm respectively and adapted to prevent the tip of the needle from emerging out of the distal end of the tip protector assembly once retracted beyond the claws.
[0014] The safety tip protector assembly is also provided with means adapted to engage the corresponding locking mean present on the inside surface of the catheter hub assembly for removably holding the tip protector assembly within the catheter hub assembly.
[0015] The intravenous cannula with safety shield assembly further comprises of a protector slidably arranged over the catheter tube, wherein the proximal portion of the said protector is removably attached to an attachment site at the distal portion of wing body through a locking mechanism and hence protectively covering the bevel as well as the catheter tube.
[0016] In accordance with an example, an intravenous cannula assembly with safety is provided with an enhanced needle tip protection mechanism configured to transition from an exposed state during venipuncture to a fully enclosed state after needle withdrawal. The intravenous cannula assembly comprises a tip protection assembly including a guiding structure that enables relative axial movement between the needle and the tip protection assembly for a predefined withdrawal length. A blocking structure includes a first arm and a second arm extends from a distal end of the guiding structure on opposite lateral sides of a needle travel path. Upon needle retraction, the blocking structure engages the needle and cooperatively forms a barrier to prevent the needle tip from re-emerging beyond the distal end of the tip protection assembly, thereby providing irreversible containment of the needle tip within the tip protection assembly and shielding the user from accidental exposure.
[0017] An advancement over prior designs is achieved by structuring the first and second arms such that their locking engagement occurs at positions laterally offset from a central axis of the needle’s travel path. This geometrically offset configuration ensures that even under a forcible forward push on the needle, the arms remain interlocked and the tip remains obstructed from protruding. The offset architecture provides a passive, geometry-based safety mechanism that is not dependent on frictional or spring loading alone, thereby enhancing both the reliability and irreversibility of needle tip retention after use.
[0018] Moreover, appropriate tolerances are provided in the tip protection assembly to enhance gripping with mating parts within the intravenous cannula assembly in its initial first state before the needle retraction. This relaxed upper tolerance reduces resistance during forming operations such as stamping or bending, thus lowering tool wear and improving dimensional yield in high-volume manufacturing environments. These improvements also simplify quality control inspection criteria while preserving the mechanical integrity and safety performance of the assembly.
BRIEF DESCRIPTION OF FIGURES
[0019] The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements.
[0020] Fig. 1 is the top view of the complete assembly of the preferred embodiment according to the present invention.
[0021] Fig. 2 is the complete assembly of the preferred embodiment in isometric view according to the present invention.
[0022] Fig. 3 is the cross sectional view of the complete assembly of the preferred embodiment according to the present invention.
[0023] Fig. 4 is the exploded view of the complete assembly of the preferred embodiment according to the present invention.
[0024] Fig. 5 is the cross sectional view of the catheter assembly.
[0025] Fig. 6 is diagram of the needle.
[0026] Fig 7 is the diagram of the safety tip protector assembly.
[0027] Fig. 8 is the diagrammatic representation of the needle in retracted position, before the tip of the needle passes the claws of the tip protector assembly.
[0028] Fig. 9 is the diagrammatic representation of the needle in retracted position after the tip passed the claws of the tip protector assembly but before the tip protector assembly securing the tip unlocked with the catheter assembly.
[0029] Fig 10 is the diagrammatic representation of the tip protector assembly securing the tip of the needle and unlocked with the catheter assembly.
[0030] Fig. 11 is the diagrammatic representation of retracted needle hub assembly along with the tip protector assembly securely covering the tip of the needle.
[0031] Fig. 12 is the isometric diagrammatic representation of retracted needle hub assembly along with the tip protector assembly securely covering the tip of the needle.
[0032] FIG. 13 illustrates the tip protector assembly, in an embodiment.
[0033] FIG. 14 illustrates the tip protector assembly with dimensions of different components and structures, in an exemplary embodiment.
[0034] FIG. 15 illustrates the tip protector situated within the complete assembly with appropriate tolerances to facilitate appropriate manufacturing and deployment of the tip protector assembly.
DETAILED DESCRIPTION OF INVENTION
[0035] This description is not intended to be a detailed log of all the possible ways in which the invention may be implemented, or all features that may be added to the instant invention. For example, features illustrated with respect to a particular embodiment may be incorporated into other embodiment, and features illustrated with respect to a particular embodiment may be deleted from that embodiment. In addition, numerous variations and additions to the various embodiment suggested herein will be apparent to those skilled in the art in light of the present disclosure, which do not depart from the present invention. Hence the following specifications are intended to illustrate some particular embodiment and variations thereof.
[0036] In a preferred embodiment of the present invention as referred in figures 1 to 5, an intravenous delivery catheter assembly (200) removably located coaxially over a needle (100) such that the needle (100) can be withdrawn from the assembly (200) after successful placement of the delivery end of the catheter tube (201) in patient vein. The intravenous delivery catheter assembly (200) further comprises a catheter tube (201), catheter holder (202), silicon tube (203), a wing body (204), wherein a safety tip protector assembly (300) coaxially arranged over the needle (100) is removably arranged inside the wing body (204) and is removably held with an inter locking mechanism attained with engagement of a mean e.g. protruding rib pattern (205) present circumferentially upon the inside surface of the wing body (204) with corresponding means present upon body of the tip protector assembly (300) adapted to lock itself with the rib pattern (205). The said interlocking mechanism may be disengaged with application of force in the proximal direction. A cover (10) is slidably arranged over the catheter tube (201) and is removably attached with the catheter hub/ wing body (204) thereby protectively covering the bevel (101) as well as the catheter tube (201). The assembly further includes an optional port (206) along with the port cap (207). A needle hub assembly (400) is coaxially mounted over the proximal end of the needle (100) and consist essentially of a needle hub (401), a flash back chamber (402) attached at the proximal portion of the needle hub (401) and a luer lock (403) releasably attached at the distal portion of the said flash back chamber (402). The distal end of the needle hub assembly (400) is present with an elongation (404) adapted to push the safety tip protector assembly (300) in distal direction from its proximal end.
[0037] As referred in figure 6, the needle (100) also has a bulge/dent (102) in the distal section of the needle and more specifically near the tip/ bevel (101). The bulge (102) has an outer profile, dimension of which is larger than maximum dimension of the principal outer profile of the needle (100).
[0038] As referred in figures 7, the body of the tip protector assembly (300) of the present invention is made of non reactive metal preferably but not limited to stainless steel. The tip protector assembly (300) includes a retaining strip preferably a rectangular/ square shape acting as a base (301) and is present with a needle through bore (302). A stem (303) which is extension of one side of the base (301) in distal direction and further bending in a direction parallel to the base portion and is present with a needle through bore (304) upon said parallel portion (305) in such a manner that the needle through bores (302) and (304) provides a passage (306) for the needle (100). The needle through bore (302) is having a profile larger than the principle profile of the needle (100) but lesser than the outer profile of the bulge/ dent (102) present on the needle (100). The needle through bore (304) is having a profile slightly larger than the outer profile of the bulge (102) and allows the bulge (102) to pass through it. The stem (303) is having length lesser than the length of the needle portion between the bulge (102) and the tip (101). The tip protector assembly (300) further comprises of first arm (307) and second arm (308) which are extension of the sides of the base (301) adjacent to the side attached with stem (303) in distal direction.
[0039] The first arm (307) of the tip protector assembly (300) is having a mean (309) adapted to engage the corresponding locking mean e.g. rib pattern (205) present on inside surface of the catheter hub assembly (200) for removably holding the tip protector assembly (300) within the catheter hub assembly (200) in such a manner that it can be easily removed merely by applying pressure outwardly thereto. The first arm (307) further bends at an angle after the said mean (309) and further extended in the angular direction in such a manner that the claw (310) present at the end of the first arm blocks the pathway of the needle (100) along the direction to the axial said needle passage (306) and distal to the needle through bore (304). The claw (310) is actually the extension of the first arm (307) in which the end part of the arm is bent twice in such a manner that it forms claw like structure so that once the tip (101) gets inside, the same get trapped inside and could not escape even after being pushed further in the distal direction. It is pertinent to mention that the first arm (307) is sufficiently long enough so as to block the needle pathway beyond the tip (101) of the needle (100) while the bulge (102) being engaged with the needle through bore (302); hence the path of the tip (101) of the needle (100) is blocked by the claw (310) in case the needle (100) is pushed in the distal direction. The second arm (308) similar to the first arm (307) also extends distally in axial direction and also having mean (311) adapted to get engaged with the rib (205) present inside the catheter hub assembly (200). The position of the said mean (311) on the second arm (308) is just opposite to the position of the mean (309) on the first arm (307) so that the both may be simultaneously engaged with the rib (205) so as to provide efficient locking. The second arm (308) is further bend after the said mean at a certain angle towards the axis longitudinal to the needle passage (305). The second arm (308) is having sufficient length that the claw (312) present on the second arm (307) blocks the needle path above the claw (310) of the first arm (307).
[0040] The tip protector assembly (300) is such arranged that the movement of the needle (100) in the proximal direction beyond the bulge (102) portion is stopped by the needle through bore (302) present at the base portion (301) while a small portion of the needle preferably portion distal to bevel (101) still being remaining beyond the distal side of the needle through bore (304) present on the extended parallel portion (305) of the stem (303), hence ultimately ensuring movement of the needle (100) along one trajectory only passing through both afore said bores (302, 304).
[0041] While arranging the tip protector assembly (300) along the needle (100), proximal end of the needle (100) slightly parting both arms (306,307) of the tip protector assembly (300) is inserted from the through bore (304) present on the parallel portion (305) and further travels from the through bore (302) present on the base (301). The needle hub assembly (400) is then affixed with the proximal end of the needle (100). The slightly parted arms (307,308) are thus stored with spring action restoring force. The needle (100) along with the tip protector assembly (300) is then arranged with the catheter assembly (200) by inserting the tip (101) of the needle from the rear portion of the catheter hub assembly (200) and the needle (100) is pushed further in the distal direction so that the needle tip (101) travels all along the catheter assembly and finally comes out at the end of the catheter tube (201). The elongation (404) present at distal end of the needle hub assembly (400) is long enough to push the tip protector assembly(300) to such an extent inside the catheter hub assembly (200) so that the means (309, 311) present on the arms (307, 308) get removably attached with the ribs (205) present in the catheter hub (200). Any further movement of the projection (404) is stopped due to engagement of proximal end of the wing body (204) with the distal end of the needle hub assembly upon which the elongation (404) is mounted. The means (309,311) present on the arms (306,307) of the tip protector assembly (300) get engaged with the ribs (205) present in the catheter hub assembly (200) thereby removably locking the shield assembly within the catheter hub assembly (200) in a release able manner.
[0042] To use the IV Cannula with the tip protector assembly (300) on patient, the needle cover (10) is first removed while holding the cannula by the wing body (204) so that the needle (100) along with the tip protector assembly (300) does not get pulled out from the catheter hub (204). After, removal of the needle cover (10) the IV cannula is used over the patient by a medical practitioner to puncture the vein of the patient. After successful puncture of the vein by the tip (101) of the needle (101) and confirmed by the flow of blood in the flash chamber (402), the needle hub assembly (400) is slowly pulled out with one hand while holding the catheter hub assembly (200) securely in the place with the second hand. The needle slowly travels backwards leaving catheter tube and tip (101) passes firstly the wing body/catheter hub then passes the claw (312) of the second arm (308) and then claw (310) of the first arm (307) and the needle (100) travels further in the proximal direction till the bulge (102) get engaged with the needle through bore (302). The moment the tip (101) passes the claws (312,310) of the arms (308,307) the restoring force present in the arms (308,307) makes them move in transverse direction towards the needle pathway and the claws (312,310) present on arms (308,307) get positioned so as to block the movement of the needle (100) in the distal direction. Further pulling force applied on the needle hub assembly (400) in the proximal direction pulls out the tip protector assembly (300) out of the catheter hub assembly (200) whereby the tip (101) of the needle gets secured by the tip protector assembly (300) without any risk or danger of needle prick to the medical practitioner. The used needle with the tip protector assembly (300) locked can then be safely disposed off. Figures 8 – 12 may be referred to.
[0043] The following description pertains to improvements to the intravenous cannula assembly or the intravenous delivery catheter assembly (200) disclosed above in the document, and particularly to modifications in the configuration and manufacture of a blocking structure 1302 formed by a first arm 1304 and a second arm 1306 of a tip protection assembly 1300, as illustrated in FIGURE 13 and FIGURE 14 appended hereto. The tip protection assembly 1300 is also referred to as the tip protector assembly 1300 throughout this document interchangeably without limitations.
[0044] In an example, the intravenous cannula assembly (300) is provided that includes a needle tip protection mechanism. The intravenous cannula assembly (300) has a hollow needle such as the needle (100) with both its distal and proximal ends, a catheter tube similar to the catheter tube (201) positioned coaxially and removably over the needle (100) so that the catheter tube (201) can remain inside a patient's vein after the needle (100) is withdrawn, and the tip protection assembly (1300) arranged coaxially around the needle (100). The tip protection assembly (1300) is adapted to switch from a first condition, where the needle tip (101) is exposed for venipuncture, to a second condition, where the tip (101) is enclosed after being withdrawn. The tip protection assembly (1300) includes a guiding structure (1308) that defines a through-passage for the needle (100), allowing the needle (100) and the tip protection assembly (1300) to move axially relative to one another over a defined withdrawal distance. The blocking structure (1302) includes the first arm (1304) and the second arm (1306) that extend from a distal end of the guiding structure (1308) and are situated on either side of the needle’s travel path shown as X-X axis. The blocking structure (1302) is configured to enclose the needle (100) once it is withdrawn over the specified distance. The first arm (1304) and the second arm (1306) act together to create a barrier that prevents the needle tip (101) from protruding past a distal end of the tip protection assembly (1300) after retraction, thereby locking the needle (100) inside and shielding the user from exposure.
[0045] In an example, the first arm (1304) and the second arm (1306) are constructed in such a way that their engagement occurs at a position (engagement position 1310) offset from the needle’s path of travel XX when in the second (retracted) state. This configuration ensures that even if a strong forward force is applied to the needle (100), the first arm (1304) and the second arm (1306) will not disengage to allow the needle (100) to exit the tip protector assembly (1300).
[0046] In an example, the guiding structure (1308) includes a substantially rectangular or square enclosed hollow section having a top (1312) and a base (1314). The base (1314) incorporates the first bore (302) (similar to as shown in FIG. 7), and the top (1312) includes the second bore (304) (similar to as shown in FIG. 7), with the both the bores (302) and (304) being aligned axially to form a continuous passage for the needle (100) along the travel path XX.
[0047] In an example, the needle (100) has a retention element (102) similar to the bulge (102), as shown in FIG. 6. The bulge (102) is designed to engage with a part of the tip protection assembly (1300) to assist in locking the needle (100) into position once it is retracted.
[0048] In an example, the first bore (302) of the guiding structure (1308) is dimensioned to have a diameter smaller than the outer profile of the bulge (102) on the needle (100). As a result, when the needle (100) is withdrawn to a defined length, the bulge (102) is stopped by the first bore (302), preventing further proximal movement and keeping the needle tip securely inside the tip protection assembly (1300).
[0049] In an example, the engagement point or engagement position (1310) of the first arm (1304) and the second arm (1306) in the second state lies outside of a direct line projected along the needle's travel path XX. This positioning blocks any forward re-entry of the needle tip once it has been retracted.
[0050] In an example, the first arm (1304) and the second arm (1306) are shaped to curve inward toward each other at their distal ends. They form a pair of inwardly biased jaws (1316) and (1318) that close around the needle (100) after retraction, and their closure remains offset from the needle’s travel path XX. The engagement position (1310) lies along the YY axis and the offset is the difference between the distance of the axis XX and YY horizontally.
[0051] In an example, the first arm (1304) and the second arm (1306) are fabricated from an elastic metal or metal alloy. This material choice enables the arms (1304) and (1306) to flex during manufacturing and needle (100) insertion and then return to a default position that obstructs the needle’s path once it is retracted.
[0052] In an example, the first and second arms (1304) and (1306) are dimensioned and located such that, after retraction, if a strong forward force is applied to the needle (100), its tip will be deflected against arm surfaces. This configuration prevents the arms (1304) and (1306) from being spread or dislodged due to their offset arrangement and inward curvature, thereby avoiding both accidental and intentional reuse.
[0053] In an example, the first arm (1304) and the second arm (1306) are made of stainless steel and are formed with a width of 2.9 mm, having a tolerance range of +0.20 mm and –0.05 mm. The expanded upper tolerance improves the arms’ elasticity during both fabrication and use, enhances closure reliability of the jaws (1316) and (1318) during needle (100) retraction, and also decreases tool wear, machining complexity, and the effort required for inspection during production.
[0054] In an example, the intravenous cannula assembly or also referred to as intravenous delivery catheter assembly (200) interchangeably is described that includes the needle (100), the catheter tube (201) arranged coaxially over the needle (100), and the tip protection assembly (1300) with the blocking structure (1302) made up of the first arm (1304) and the second arm (1306) designed to enclose the needle tip after retraction. The first arm (1304) and the second arm (1306) are constructed from an elastic metal material and are each 2.90 mm wide with a manufacturing tolerance of +0.20 mm and –0.05 mm. This increased upper tolerance improves the flexibility and elasticity of the arms (1304) and (1306) both during production and in use, leading to better closure of the jaws (1316) and (1318) around the retracted needle tip, reduced wear on manufacturing tools, higher yield in part formation, simplified inspection, and lower overall production cost.
[0055] In reference to FIGURE 13, the configuration of the first arm (1304) and the second arm (1306), each extending distally from opposing sides of the top (1312) of the tip protection assembly (1300), is illustrated with enhanced clarity to show their offset orientation relative to the central longitudinal axis of the needle travel path XX. As depicted, the arms (1304) and (1306) are not collinear with the central axis XX of the through-passage, but are instead spatially offset laterally and inwardly curved toward one another at their distal ends to form a pair of the inwardly biased jaws (1316) and (1318). The geometry of the arms (1304) and (1306) is such that, upon retraction of the needle (100) into the second state, the jaws (1316) and (1318) converge across the needle travel path XX in an offset manner, thereby forming a structural and irreversible barrier to any subsequent distal advancement of the needle tip (101). This offset configuration ensures that even if a compressive or axial forward force is applied proximally to the needle (100), the needle tip (101) is obstructed by the clawed arms or jaws (1316) and (1318) and cannot exit the distal end of the tip protection assembly (1300). The mechanical offset of the arms (1304) and (1306) thereby introduces an anti-rebound safety feature, not present in conventional coaxial jaw configurations, which substantially prevents re-exposure of the needle tip (101) and mitigates the risk of accidental needle-stick injury.
[0056] Referring now to FIGURE 14 and 15, there is depicted a dimensional and material enhancement to the same tip protection assembly (1300), specifically in tolerances the tip protection assembly (1300) when it resides within the complete assembly. In this improved version, the tolerance shown with numeral 1502 in FIGURE 15 is 2.9 mm +0.20, -0.05 mm which enhances the gripping with mating part of the complete assembly as shown in the FIGURE 15, which will increase the safety feature for locking the needle tip (101) with the tip protection assembly (1300) and the tip protection assembly (1300) will not come out without locking the needle tip (101). In an example, the arms (1304) and (1306) are manufactured from a spring-grade stainless steel or any other material without limitations, in an exemplary embodiment, without limitations. This widened upper tolerance as shown in FIGS. 14 and 15 provides enhanced elastic deformation characteristics during both the forming process and functional usage. The increased elasticity enables a smoother inward biasing of the arms (1304) and (1306) during needle retraction to form the jaws (1316) and (1318) in the second state, promoting reliable engagement of the jaws (1316) and (1318) over the needle tip (101) without requiring external actuation or alignment. Furthermore, the relaxed upper tolerance reduces resistance during forming operations such as stamping or bending, thus lowering tool wear and improving dimensional yield in high-volume manufacturing environments. These improvements also simplify quality control inspection criteria while preserving the mechanical integrity and safety performance of the assembly.
[0057] The improvements illustrated in FIGURES 13 to 15 are applicable to the structure of the intravenous cannula assembly (200) as disclosed in the document and figures and are particularly directed toward enhancing both the safety reliability and the manufacturing scalability of the tip protection assembly (1300). These features are contemplated as being combinable with any of the embodiments described herein and are particularly supportive of the invention as now claimed in the appended claims, including those that emphasize arm offset, engagement geometry, elastic material properties, and manufacturing tolerances.
[0058] It will be understood by those skilled in the art that the intravenous cannula assembly described herein may be implemented using various equivalent components, materials, and structural variations, without departing from the scope of the invention as defined by the appended claims.
[0059] It is expressly understood that the tip protector assembly (1300) described herein, although illustrated in conjunction with specific embodiments of intravenous cannula assemblies and catheter hub configurations, is not limited thereto. The same or similar tip protector assembly (1300) can be adapted, configured, or retrofitted into a wide variety of catheter formats, including but not limited to central venous catheters, arterial lines, dialysis access devices, midline catheters, and peripheral intravenous devices, without limitations. Likewise, the safety mechanism may be integrated with various catheter hub geometries, sizes, or port arrangements commonly used in clinical practice, without departing from the functional essence of the present invention.
[0060] Further, minor changes in supporting or interfacing components such as catheter holder shapes, locking rib patterns, guide channel geometries, or manufacturing tolerances shall not be construed as departing from the scope and spirit of the invention. The core inventive contribution lies in the irreversible containment of the needle tip via a mechanically offset, clawed arm mechanism, which can be dimensionally and structurally adapted to suit diverse catheter applications, manufacturing practices, and regulatory requirements, all while preserving the same safety function intended to reduce the risk of needle-stick injuries. The invention is thus to be interpreted broadly, covering all embodiments that implement substantially the same function, in substantially the same way, to achieve substantially the same result.
[0061] Although specific embodiments and structural configurations of cannulas, catheters, and associated tip protection assemblies have been illustrated and described herein, it is contemplated that alternative forms of cannula tubes, catheter insertion geometries, locking and retraction mechanisms, and tip shielding arrangements may be utilized. For example, the catheter tube (201) may be formed from flexible polymeric materials including but not limited to polyurethane, silicone, or PTFE, without limitations, and may be configured to include wings, hubs, or other anchoring structures as commonly known in the art.
[0062] The dimensions, tolerances, and materials described with reference to the arm structures, claws, and needle guides may be adjusted within medically acceptable design parameters, including but not limited to configurations adapted for pediatric, adult, or specialized intravenous access procedures. Similarly, the orientation and shape of the claws or jaws, or engagement surfaces may include angled, stepped, interlocking, or self-biasing features, whether symmetric or asymmetric, provided that the function of irreversible needle tip protection is retained.
[0063] References to stainless steel or elastic metallic components are intended to cover equivalent springable alloys, composite materials, or manufacturing methods such as laser cutting, EDM machining, stamping, or molding, that achieve the necessary functional resilience and deformation response.
[0064] The guiding and blocking structures disclosed herein may also be integrated into or removably connected to cannula holders, catheter hubs, or medical-grade syringe interfaces, and the locking or engagement mechanisms may be implemented by mechanical interference, friction fit, snap-fit, rib/groove interaction, or integrated biasing members.
[0065] All directional references (e.g., distal, proximal, axial, transverse) are provided for clarity and are not intended to limit the orientation or configuration in clinical use. Unless otherwise indicated, dimensions, materials, and operational sequences are provided by way of example only and not as limitations.
[0066] The term “comprising” as used in the claims shall not be interpreted to exclude other technically equivalent elements or steps. Where the context allows, the terms “a,” “an,” and “the” should be interpreted as meaning “at least one.” The invention also includes equivalents, modifications, and alternatives that may not have been specifically recited but fall within the scope and spirit of the present disclosure and the claims that follow.
[0067] Accordingly, the foregoing description is intended to be illustrative rather than restrictive, and the invention is not limited to the specific embodiments described and illustrated, but includes all equivalents falling within the scope of the appended claims. , Claims:CLAIMS
We claim:
1. An intravenous cannula assembly (200) with a needle tip protection mechanism, comprising:
 a hollow needle (100) having a distal end with a tip (101) and a proximal end;
 a catheter tube (201) disposed coaxially and removably over the needle (100) such that the catheter tube (201) can remain in a patient’s vein after withdrawal of the needle (100);
 a tip protection assembly (1300) disposed coaxially around the needle (100) and configured to transition from a first state in which the needle tip (101) is exposed for venipuncture to a second state in which the needle tip (101) is enclosed after withdrawal from the catheter tube (201);
 wherein the tip protection assembly (1300) comprises:
   a guiding structure (1308) having a through-passage for the needle (100) and configured to allow relative axial movement between the needle (100) and the tip protection assembly (1300) for a defined length during withdrawal along a needle travel path XX;
a blocking structure (1302) comprising a first arm (1304) and a second arm (1306) extending from a distal end of the guiding structure, positioned on opposite sides of the needle travel path XX, the blocking structure (1302) configured to enclose the needle (100) upon retraction over the defined length; and
wherein the first and second arms (1304, 1306) cooperate to form a barrier that prevents the needle tip (101) from re-emerging beyond the distal end of the tip protection assembly (1300) after the retraction, thereby irreversibly securing the needle (100) within the arms (1304 and 1306) and preventing exposure of the tip (101) to a user.
2. The intravenous cannula assembly (300) of claim 1, wherein the first arm (1304) and the second arm (1306) are structured such that their engagement in the second state occurs at a position offset from the needle travel path XX, thereby ensuring that even a forcible forward push on the needle (100) cannot disengage the arms (1304, 1306) to exit the tip protector assembly (1300).
3. The intravenous cannula assembly (300) of claim 1, wherein the guiding structure (1308) comprises an enclosed, substantially rectangular or square hollow region having a top region (1312) and a base region (1314), the base region (1314) including a first bore (302) and the top region (1312) including a second bore (304), wherein the first bore (302) and second bore (304) are axially aligned to provide a through-passage for the needle (100) along the needle travel path XX.
4. The intravenous cannula assembly (300) of claim 3, wherein the needle (100) comprises a retention feature in the form of a bulge (102) located proximally relative to the tip (101), the bulge (102) being configured to engage with a corresponding portion of the tip protection assembly (1300) to facilitate locking of the needle (100) upon retraction.
5. The intravenous cannula assembly (300) of claim 4, wherein the first bore (302) of the guiding structure (1308), has a diameter smaller than an outer profile of the bulge (102) on the needle (100), such that upon retraction of the needle (100) by a specified length, the bulge is obstructed by the first bore (302), thereby preventing further proximal movement of the needle (100) and ensuring that the needle tip (101) remains enclosed within the tip protection assembly (1300).
6. The intravenous cannula assembly (300) of claim 2, wherein the engagement position (1310) of the first arm (1304) and the second arm (1306) in the second state lies outside a direct projection of the needle travel path XX, thereby obstructing forward re-emergence of the needle tip (101) after the retraction.
7. The intravenous cannula assembly (300) of claim 6, wherein the first arm (1304) and the second arm (1306) are curved inward toward each other at their distal ends to form inwardly biased jaws (1316) and (1318) that close upon the needle (100) after retraction with a closure of the jaws (1316) and (1318) having the offset from the needle travel path XX.
8. The intravenous cannula assembly (300) of claim 1, wherein the first arm (1304) and the second arm (1306) are formed of an elastic metal or metal alloy configured to flex during and before needle passage in a manufacturing step and return to a default obstructing position upon the retraction after use of the cannula assembly (300).
9. The intravenous cannula assembly (300) of claim 8, wherein the first arm (1304) and the second arm (1306) are dimensioned and positioned such that a forceful forward push on the needle (100) after the retraction causes the needle tip (101) to deflect against arm surfaces without dislodging or spreading them due to the offset and being curved inward toward each other, thereby preventing accidental or intentional reuse.
10. The intravenous cannula assembly (300) of claim 8, wherein the first arm (1304) and the second arm (1306) are manufactured from stainless steel and dimensioned to fit within the cannula assembly (300) to have a tolerance of 2.9 mm, +0.20 mm and –0.05 mm,
  such that an increased upper tolerance improves elasticity of the arms (1304) and (1306) during manufacturing and usage, facilitates improved closure of the jaws (1316) and (1318) upon retraction of the needle (100), and reduces tooling wear, machining complexity, and inspection load during production.

Dated this: 6th day of Aug, 2025
Signature:

Name: Syed Murtuza
INPA - 2633