AU2013392518B2

AU2013392518B2 - Multifunctional indwelling needle

Info

Publication number: AU2013392518B2
Application number: AU2013392518A
Authority: AU
Inventors: Jianlin Zhang
Original assignee: NANTONG HENGTAI MEDICAL APPARATUS CO Ltd
Current assignee: NANTONG HENGTAI MEDICAL APPARATUS Co Ltd
Priority date: 2013-06-14
Filing date: 2013-06-28
Publication date: 2017-08-10
Anticipated expiration: 2033-06-28
Also published as: WO2014198077A1; AU2013392518A1

Abstract

A multifunctional indwelling needle, comprising a sleeve assembly (1) and a needle assembly (2), as well as an anti-reflux valve (14), an anti-stab safety device and a needleless positive pressure connector (5). The anti-reflux valve (14) is arranged in a middle cavity of a sleeve seat (11) and in the axial direction thereof, and at the front end of a flexible tube (3) communicated with said sleeve seat (11). The anti-stab safety device is arranged on a needle seat (22), and the needleless positive pressure device (5) is arranged on an external connector (4). The anti-stab safety device and the needleless positive pressure device (5) are both springless type devices. The multifunctional indwelling needle prevents blood overflow and resultant contamination, and avoids medical personnel being stabbed when extracting the needle. In addition, the springless structure avoids the rusting problems of springed structures, is safer and more hygienic, and ensures work stability and reliability.

Description

MULTIFUNCTION INDWELLING NEEDLE

[0001] TECHNICAL FIELD

[0002] The present disclosure relates to indwelling needles, and particularly, to a closed type multifunction indwelling needle, which is capable of preventing needle stick injures, preventing backflow, and being stable, safe, and hygienic.

[0003] BACKGROUND

[0004] Intravenous indwelling needle, also knowns as an intravenous remained trocar, has been widely used in clinical application, because it can reduce patients’ suffering due to repeated venous puncture, fear of injections, and patients’ restlessness, also because it is convenient to be used in clinical medication and rescue medication for critical patients, and can reduce the workload of nurses. The indwelling needle includes a soft catheter/cannula, which can be retained in the blood vessels, and a stainless steel puncturing needle. When in use, the cannula together with the puncturing needle is punctured into the blood vessel. Then, in the condition where the cannula is totally punctured into the blood vessel, the puncturing needle is pulled out of the cannula (blood vessel), and the soft cannula is indwelled in the blood vessel for infusion of medicinal fluids.

[0005] The indwelling needles includes open type indwelling needles, closed type indwelling needles, safety (anti-needle-stick-injures) indwelling needles, and anti-backflow type indwelling needles. Currently, the indwelling needle has the following shortcomings.

[0006] Each indwelling needle has a single function, and can’t achieve several functions simultaneously. Hospital needs indwelling needles having several kinds of specifications, according to application amount of each specification and each model. This brings a lot of trouble to purchase and inventory management, and medical workers needs to choose indwelling needle according to different models and different functions. 1 [0007] According to structures of components of the indwelling needle, the anti-needle-stick-injures type indwelling needle structure includes the following ways.

[0008] After puncturing, a button on the indwelling needle is pressed, and an inner needle is pulled into a needle sheath via a spring, thereby the inner needle is received in the needle sheath (For example: JP 10-52499, patent application publication No. CN 101011613A).

[0009] A spring-loaded needle protection mechanism is set inside an outer needle bush. The needle protection mechanism is separated from the outer needle bush, and covers a front portion of the inner needle (for example: patent application publication No. CN 101011613A) by pulling out the inner needle.

[0010] Both of the two above mentioned ways need spring. If the spring cannot reset, the steel needle will not be protected. Therefore, the disadvantage of the two ways is not reliable enough.

[0011] In the structure of the anti-backflow type indwelling needle, CN 201257220Y discloses an anti-backflow type indwelling needle. The anti-backflow type indwelling needle prevents backflow by fixing an anti-backflow valve in a seat or providing a positive pressure connector on the Y-shaped indwelling needle. Both of the two ways have a shortcoming of single measure. For example, the antibackflow valve cannot be completely closed. In the structure of the positive pressure connector, if the medical workers pull out the infusion apparatus too fast, the positive pressure connector has not time to form a positive pressure. It may cause a back blood phenomenon and make less reliable.

[0012] In addition, the current positive pressure connector has some drawbacks. For example, patent application publication No. CN 101912664A discloses a disposable positive pressure connector, and provides a positive pressure to the disposable positive pressure connector via a spring. Therefore, the spring needs a high rust resistance character and demands safety and health.

[0013] Therefore, it is desired to provide a multifunction indwelling needle, which is capable of preventing needle stick injures, preventing backflow, and being stable, safe, and hygienic. 2

[0014] SUMMARY

[0015] The present disclosure aims to provide a multifunction indwelling needle, which is capable of preventing needle stick injures, preventing backflow, and being stable, safe, and hygienic.

[0016] To solve the above-mentioned problem, the technical solution of the present disclosure explains as followings.

[0017] The multifunction indwelling needle includes a cannula assembly, a needle assembly, an anti-backflow valve, and a non-spring-loaded anti-needle-stick-injures safety mechanism. The cannula assembly includes a cannula seat, a cannula, and a separating plug. The cannula seat defines a hollow chamber along an axial direction thereof. The cannula communicates with the hollow chamber of the cannula seat. The separating plug plugs into a rear portion of the hollow chamber of the cannula seat. A middle portion of the cannula seat communicates with an outer connector via a soft catheter. The needle assembly includes a needle and a needle seat at a distal end of the needle. A handle is set on the needle seat. A needle tip of the needle penetrates the separating plug, the cannula seat, and the cannula and extends from one end of the cannula seat to the distal end of the cannula seat along the axial direction of the cannula seat. The anti-backflow valve is assembled in the front portion of the cannula seat. The non-spring-loaded anti-needle-stick-injures safety mechanism is arranged in the needle seat.

[0018] In some embodiments, the anti-backflow valve comprises a tubular body and a wedge portion at a bottom of the tubular body, a middle portion of a bottom of the wedge portion defines a linear gap communicating with an inner hole of the tubular body, a radial flange, which can inserted into a front portion of the hollow chamber of the cannula seat, extends from a top end of the tubular body, a pair of pressing protrusions extend from a middle portion of an outer sidewall of the cannula seat, the pressing protrusions correspond to opposite ends of the linear gap, and the antibackflow valve and the middle portion of the cannula seat are made of elastic material.

[0019] In some embodiments, the anti-needle-stick-injures safety mechanism comprises a core rod, a multi-stage retractable sleeve, and a ferrule, the needle seat is substantially a tube with a closed top end, a top end of the core rod is connected to an 3 axial center of the needle seat, a lower end of the core rod is connected to a distal end of the needle, a flange of the lower end of the core rod inserts into an opening of a top end of a first stage retractable sleeve, a flange of a lower end of a second stage retractable sleeve inserts into an opening of a top end of a neighboring outer stage retractable sleeve, a lower end of the outermost stage retractable sleeve is connected to the ferrule, an outer surface of the ferrule is inserted into an opening at a lower end of the needle seat, an axial center of the ferrule defines a through hole for passing the needle, and the needle entirely enters the multi-stage retractable sleeve after both of the two stage retractable sleeves are pulled out of the needle seat by pulling the ferrule.

[0020] In some embodiments, an elastic eccentric cone is assembled inside the ferrule, a slanted through hole is defined in the eccentric cone and extends from a bottom center to a top point of the eccentric cone, a diameter of the slanted through hole is slightly larger than an external diameter of the needle, the top point of the eccentric cone faces one side of the needle, and a bottom of the eccentric cone is coupled with an opening of the ferrule.

[0021] In some embodiments, the ferrule is coupled with the cannula seat through a fast detachable structure.

[0022] In some embodiments, the fast detachable structure comprises a cylinder arranged in a center of the ferrule, the cylinder defines a through hole for passing the needle at a central portion of the cylinder, the external diameter of the cylinder match the dimension of a distal end of the cannula seat, and the cylinder is embedded in the cannula seat and is coupled with a distal end of the cannula seat by over fitting.

[0023] In some embodiments, the fast detachable structure comprises a pair of clamps at a front portion of the ferrule, and the distal end of the cannula seat defines engagement grooved corresponding to the clamps.

[0024] In some embodiments, the outer connector is a substantially Y-shaped transparent tee, a first end of the Y-shaped transparent tee is connected to the soft catheter, a heparin cap or a cover cap is assembled with a second end of the Y-shaped transparent tee, and a third end of the Y-shaped transparent tee is connected to a positive pressure needless connector through a Luer taper. 4 [0025] In some embodiments, the positive pressure needless connector comprises a positive pressure housing, a connector seat, and a silicone stopper, the positive pressure housing is substantially tubular and has a Luer taper at an upper end thereof, the lower end of the positive pressure housing is connected to an upper end of the connector seat, a plurality of axial guide groove are defined in an internal sidewall of the positive pressure housing, the internal sidewall has the same diameter, the silicone stopper is hollow and is shaped to be fit with the positive pressure housing, the silicone stopper plugs in the positive pressure housing, a top end of the silicone stopper is a cylinder, the silicone stopper has a wave tube with the same diameter, a lower end of the silicone stopper is connected to an upper end of the connector seat with adhesive, the connector seat has a ring-shaped projection with an external diameter less than an internal diameter of a lower chamber of the positive pressure housing at a center of the upper end of the connector seat, the lower end of the silicone stopper is adhered to the internal circumference surface of the ring-shaped projection, balancing holes are defined in the ring-shaped projection and communicates with air, a lower end of the connector seat is a Luer taper joint, the Luer taper joint has a conical tube, connecting to an additional connector at a central portion thereof, and a plurality of radial guide holes are defined between the ring-shaped projection and an upper end of the conical tube.

[0026] Advantages of this present disclosure are the followings: the anti-backflow valve, the anti-needle-stick-injures safety mechanism, and the positive pressure needless connector cooperatively form a closed indwelling needle. The indwelling needle can prevent blood overflow. The needle is shield by the anti-needle-stick-injures safety mechanism, thereby protecting the medical workers from needle-stick-injures. Both the anti-backflow valve and the positive pressure needless connector can prevent backflow, this increase reliability. After infusion, a heparin cap is avoided, this increases work efficiency and decreases fear of infusion of patients. Scalp heedle can be avoided due to usage of the positive pressure needless connector, and the syringe is directly inserted into the positive pressure needless connector. Meanwhile, the anti-needle-stick-injures safety mechanism is a non-spring-loaded anti-needle-stick-injures safety mechanism, and the positive pressure needless 5 connector is a non-spring-loaded positive pressure needless connector, thereby avoiding corrosion of spring. It is safer, more hygienic, more stable, and more reliable.

[0027] In addition, a middle portion of a bottom of the wedge portion defines a linear gap, and a radial flange corresponds to the linear gap. When the medical workers presses the radial flange, the anti-backflow valve can be opened, thereby avoiding puncturing and increasing the suffering of patients.

[0028] The eccentric cone can totally covers the needle when the retractable sleeve is retracted for a force or the gravity, this protects the medical worker from needle-stick-injures.

[0029] The ferrule can be coupled with the cannula seat through a fast detachable structure. After the needle enters the cannula seat, the ferrule is connected to the cannula seat. Therefore, dislocation and isolation between the needle seat and the cannula seat are avoided during puncturing. Meanwhile, the ferrule is avoided to be fall off when the needle is not totally covered by the multi-stage retractable sleeve, if pulling out of the needle.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a schematic view of a multifunction indwelling needle.

[0032] FIG. 2 is an axial cross section view of a cannula assembly of the multifunction indwelling needle of FIG. 1.

[0033] FIG. 3 is an enlarged view of an anti-backflow valve of FIG. 2.

[0034] FIG. 4 is a cross section view of the anti-backflow valve, taken along a line A-A of FIG. 3.

[0035] FIG. 5 is a cross section view of a needle assembly and an anti-needle-stick-injures safety mechanism.

[0036] FIG. 6 is a view illustrating assembling the anti-needle-stick injures safety mechanism.

[0037] FIG. 7 is a schematic view of a positive pressure needless connector.

[0038] FIG. 8 is a cross section view of the positive pressure needless connector. 6 [0039] FIG. 9 is a cross section view of the positive pressure needless connector, taken along a line B-B of FIG. 8.

[0040] FIG. 10 is a cross section view of the positive pressure needless connector, taken along a line C-C of FIG. 8.

[0041] FIG. 11 is a bottom view of a positive pressure housing of FIGS. 7~9.

[0042] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Referring to FIGS. 1-11, a multifunction indwelling needle of the present disclosure includes a cannula assembly 1 and a needle assembly 2.

[0044] The cannula assembly 1 includes a cannula seat 11, a cannula 12, and a separating plug 13. The cannula seat 11 defines a hollow chamber along an axial direction. A front portion of the cannula seat 11 is fixedly connected to the cannula 12. The cannula 12 communicates with the hollow chamber of the cannula seat 11. The separating plug 13 plugs into a rear portion of the hollow chamber of the cannula seat 11. A middle portion of the cannula seat 11 communicates with an outer connector 4 via a soft catheter 3. A hemostatic clip can be applied on the soft catheter 3.

[0045] In this embodiment, the outer connector 4 is a substantially Y-shaped transparent tee. A first end of the Y-shaped transparent tee is connected to the soft catheter 3, a heparin cap or a cover cap is assembled with a second end of the Y-shaped transparent tee, and a third end of the Y-shaped transparent tee is connected to a positive pressure needless connector 5 through a Luer taper.

[0046] The needle assembly 2 includes a needle 21 and a needle seat 22 at a distal end of the needle 21. A handle 28 is set on the needle seat 22. A needle tip of the needle 21 penetrates the separating plug 13, the cannula seat 11, and the cannula 12 and extends from one end of the cannula seat 11 to the distal end of the cannula seat 11 along the axial direction of the cannula seat 11.

[0047] In this present disclosure, the multifunction indwelling needle also includes an anti-backflow valve 14, an anti-needle-stick-injures safety mechanism, and the positive pressure needless connector 5. The anti-backflow valve 14 is assembled in the front portion of the cannula seat 11, and is positioned before the soft catheter 3. 7 2013392518 12 Jan 2016

The anti-needle-stick-injures safety mechanism is a non-spring-loaded anti-needle-stick-injures safety mechanism, and is arranged in the needle seat 22. The positive pressure needless connector 5 is a non-spring-loaded positive pressure needless connector.

[0048] Referring to FIGS. 3-4, the anti-backflow valve 14 includes a tubular body and a wedge portion 142 at a bottom of the tubular body. A middle portion of a bottom of the wedge portion 142 defines a linear gap 144, which is in communication with an inner hole 143 of the tubular body. A radial flange 141, which can inserted into a front portion of the hollow chamber of the cannula seat 11, extends from a top end of the tubular body. Two pressing protrusions 15 extend from a middle portion of an outer sidewall of the cannula seat 11. The pressing protrusions 15 correspond to opposite ends of the linear gap 144. The anti-backflow valve 14 can be squeezed to be opened by pressing the two pressing protrusions 15.

[0049] The anti-backflow valve 14 can be made of soft resin material with good elasticity. The middle portion of the cannula seat 11 can be made of elastic material.

[0050] The principles of the anti-backflow valve 14 is: before puncturing, the needle 21 penetrates the separating plug 13, the cannula seat 11, the linear gap 144 of the anti-backflow valve 14, and the cannula 12 and extends from one end of the cannula seat 11 to the distal end of the cannula seat 11 along the axial direction of the cannula seat 11. The needle 21 is pulled out after puncturing. The anti-backflow valve 14 is automatically closed under an elastic force. The anti-backflow valve 14 cannot be opened under a pressure of the blood, due to the structure of the wedge portion 142. When in infusion state, the anti-backflow valve 14 is automatically opened under a pressure of medicinal fluids. The medicinal fluids successfully flow through the cannula seat 11 and the cannula 12 and finally enter veins, the anti-backflow valve 14. After the infusion is finished, the anti-backflow valve 14 is automatically closed.

[0051] Referring to FIGS. 5-6, in this embodiment, the anti-needle-stick-injures safety mechanism includes a core rod 23, a multi-stage retractable sleeve, and a ferrule 26. The needle seat 22 is substantially a tube with a closed top end. A top end (rear end) of the core rod 23 is connected to an axial center of the needle seat 22, and a lower end (front end) of the core rod 23 is connected to a distal end of the needle 21. 8 A flange 231 of the lower end of the core rod 23 inserts into an opening of a top end of a first stage retractable sleeve 24, which is located in the innermost layer. A flange 251 of a lower end of a second stage retractable sleeve 25 inserts into an opening of a top end of a neighboring outer stage retractable sleeve (This embodiment just has two stage retractable sleeves). A lower end of the outermost stage retractable sleeve is connected to the ferrule 26. An outer surface of the ferrule 26 is inserted into an opening at a lower end of the needle seat 22. An axial center of the ferrule 26 defines a through hole (a central hole of a cylinder 261) for passing the needle 21. After both of the two stage retractable sleeves 24, 25 are pulled out of the needle seat 22 by means of pulling the ferrule 26, the needle 21 entirely enters /is entirely covered by the multi-stage retractable sleeve. Therefore, the needle 21 is shielded as shown in FIG. 6.

[0052] An eccentric cone 27, made of elastic material, can be assembled inside the ferrule 26. A slanted through hole 271 is defined in the eccentric cone 27 and extends from a bottom center to a top point of the eccentric cone 27. A diameter of the slanted through hole 271 is slightly larger than an external diameter of the needle 21. The top point of the eccentric cone 27 faces one side of the needle 21 (upward side shown in FIG. 6). A bottom of the eccentric cone 27 is coupled with an opening of the ferrule 26.

[0053] The ferrule 26 can be coupled with the cannula seat 11 through a fast detachable structure. After the needle 21 enters the cannula seat 11, the ferrule 26 is connected to the cannula seat 11. Therefore, dislocation and isolation between the needle seat 22 and the cannula seat 11 are avoided during puncturing. Meanwhile, the ferrule 26 is avoided to be fall off when the needle is not covered by the multi-stage retractable sleeve, if pulling out of the needle 21.

[0054] The fast detachable structure can be: a cylinder 261 is arranged in a center of the ferrule 26. The cylinder 261 defines a through hole for passing the needle 21 at a central portion of the cylinder 26. The external diameter of the cylinder 261 match the dimension of a distal end of the cannula seat 11, thus the cylinder 261, which is embedded in the cannula seat 11, can be coupled with the distal end of the cannula seat 11 by over fitting. The cylinder 261 can be connected to the cannula seat 11 by a 9 detachable structure, such as by an engagement structure. For example, the ferrule 26 has a pair of clamps at a front portion of the ferrule 26. The distal end of the cannula seat 11 defines engagement grooves corresponding to the clamps.

[0055] It is understood that the number of the multi-stage retractable sleeve is not limited to be two. The number of the multi-stage retractable sleeve can be four or other amount. The eccentric cone 27, I not limited to be assembled inside the ferrule 26.

[0056] The principles of the anti-needle-stick-injures safety mechanism can be explained as followings.

[0057] When in a puncturing state, the retractable sleeve is retracted. The first stage retractable sleeve 24, the second stage retractable sleeve 25, and the ferrule 26 are received in the needle seat 22. The needle 21 penetrates the ferrule 26 and extends out of the needle seat 22. The needle 21 penetrates the eccentric cone 27. The eccentric cone 27 is deformed by a force of the needle 21 in the ferrule 26. The cylinder 261 of the ferrule 26, which is embedded in the distal end of the cannula seat 11, is coupled with the cannula seat 11.

[0058] Referring to FIG. 6, after puncturing, the needle seat 22 is pulled up. The core rod 23 and the needle 21 are drawn out along a direction far away from the cannula seat 11, and are in a stretching state. The first stage retractable sleeve 24 and the second stage retractable sleeve 25 stretch far away from the cannula seat 11 along the core rod 23. When the needle tip of the needle 21 retracts out of the eccentric cone 27, the eccentric cone 27 restores to make the though hole misalign with the axis of the needle 21. Thus, the needle 21 cannot pass through the through hole of the eccentric cone 27 and expose at the ferrule 26. This protects the medical workers from needle-stick-injures.

[0059] Referring FIGS. 7-11, the positive pressure needless connector 5 includes a positive pressure housing 51, a connector seat 52, and a silicone stopper 53. The positive pressure housing 51 is substantially tubular, and has a Luer taper 512 at an upper end thereof. The lower end of the positive pressure housing 51 is connected to an upper end of the connector seat 52. A number of axial guide grooves 511 are defined in an internal sidewall of the positive pressure housing 51, which has the 10 same diameter. The silicone stopper 53 is hollow and is shaped to be fit with the positive pressure housing 51. The silicone stopper 53 plugs in the positive pressure housing 51. A top end of the silicone stopper 53 is a cylinder (which seals the top of other portion of the silicone stopper 53). The silicone stopper 53 has a wave tube with the same diameter. A lower end of the silicone stopper 53 is connected to an upper end of the connector seat 52 with adhesive. When the silicone stopper 53 is in a free state, a middle portion of the silicone stopper 53 abuts against the internal sidewall of the positive pressure housing 51. The upper end of the silicone stopper 53 is received in a top portion of the positive pressure housing 51 to form a sealing structure.

[0060] The connector seat 52 has a ring-shaped projection 523 with an external diameter less than an internal diameter of a lower chamber of the positive pressure housing 51. The lower end of the silicone stopper 53 is adhered to the internal circumference surface of the ring-shaped projection 523. Two balancing holes 521 (along an axial direction shown in FIG. 9) are defined in the ring-shaped projection 523. The balancing holes 521 communicate with air. A lower end of the connector seat 52 is a Luer taper joint. The Luer taper joint has a conical tube 524, which is connected to an additional connector, at a central portion thereof. A number of radial guide holes 522 are defined between the ring-shaped projection 523 and an upper end of the conical tube 524. The guide holes 522 communicate with the guide grooves 522.

[0061] The principles of the positive pressure needless connector 5 can be explained as followings.

[0062] When the silicone stopper 53 is in a free state, the upper end, the middle portion of the silicone stopper 53 abuts against the internal sidewall of the positive pressure housing 51 at the upper end and the middle portion, thereby forming a sealing structure, and the positive pressure needless connector 5 is closed.

[0063] When a syringe is used, the syringe is connected to the upper end of the positive pressure housing 51 via the Luer taper 512. A conical tube of the Luer taper 512 is pressed in the upper chamber of the positive pressure housing 51 and presses the top end of the silicone stopper 53. The upper end of the silicone stopper 53 is 11 2013392518 12 Jan 2016 compressed inwardly, and air exhausts from the balancing holes 521. Thereby the sealing state between the silicone stopper 53 and the positive pressure housing 51 is removed, and the gap between the silicone stopper 53 and the upper portion of the positive pressure housing 51, the guide grooves 511, the guide holes 522, and a central hole of the conical tube 524 cooperatively form a fluid flow channel.

[0064] When the syringe is removed, the silicone stopper 53 is restored to abut against the positive pressure housing 51 to form a sealing structure. Meanwhile, the silicone stopper 53 presses the positive pressure housing 51 to form a positive pressure to push the medicinal fluids to flow forward, thereby preventing blood backflow.

[0065] The principles of the present disclosure can be explained as followings.

[0066] When puncturing, the needle 21 is received in the cannula 12, the needle tip of the needle 21 exposes at the cannula 12 as shown in FIG. 1. The needle 21 together with the cannula 12 punctures into the blood vessel. After puncturing, the needle 21 is pulled out of the cannula 12, and the cannula 12 is indwelled in the blood vessel.

[0067] When the needle 21 is pulled out of the cannula 12, the anti-needle-stick-injures safety mechanism totally covers the needle 21, thereby protecting the medical workers from needle-stick-injures.

[0068] When in infusion, the syringe inject medicinal fluids through a flow channel formed by the outer connector 4, the soft catheter 3, cannula seat 11, and the cannula 12.

[0069] When the syringe is removed, the positive pressure housing 51 forms a positive pressure to push the medicinal fluids to flow toward the vein. Simultaneously, the anti-backflow valve 14 can be closed by medical workers when the syringe is removed, thereby preventing blood backflow.

[0070] It will be understood that the term “comprise” and any of its derivatives (eg comprises, comprising) as used in this specification is to be taken to be inclusive of features to which it refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied. 12 2013392518 12 Jan 2016 [0071] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[0072] It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that various modifications can be made without departing from the principles of the invention. Therefore, the invention should be understood to include all such modifications in its scope. 12a

Claims

CLAIMS:

1. A multifunction indwelling needle comprising: a cannula assembly comprising a cannula seat, a cannula, and a separating plug, the cannula seat defining a hollow chamber along an axial direction thereof, the cannula communicating with the hollow chamber of the cannula seat, the separating plug plugging into a rear portion of the hollow chamber of the cannula seat, a middle portion of the cannula seat communicating with an outer connector via a soft catheter; a needle assembly comprising a needle and a needle seat at a distal end of the needle, a handle set on the needle seat, a needle tip of the needle penetrating the separating plug, the cannula seat, and the cannula and extending from one end of the cannula seat to the distal end of the cannula seat along the axial direction of the cannula seat; an anti-backflow valve assembled in the front portion of the cannula seat; and a non-spring-loaded anti-needle-stick-injures safety mechanism arranged in the needle seat, wherein the outer connector is a substantially Y-shaped transparent tee, a first end of the Y-shaped transparent tee is connected to the soft catheter, a heparin cap or a cover cap is assembled with a second end of the Y-shaped transparent tee, and a third end of the Y-shaped transparent tee is connected to a positive pressure needless connector through a Luer taper, the positive pressure needless connector comprises a positive pressure housing, a connector seat, and a silicone stopper, the positive pressure housing is substantially tubular and has a Luer taper at an upper end thereof, the lower end of the positive pressure housing is connected to an upper end of the connector seat, a plurality of axial guide groove are defined in an internal sidewall of the positive pressure housing, the internal sidewall has the same diameter, the silicone stopper is hollow and is shaped to be fit with the positive pressure housing, the silicone stopper plugs in the positive pressure housing, a top end of the silicone stopper is a cylinder, the silicone stopper has a wave tube with the same diameter, a lower end of the silicone stopper is connected to an upper end of the connector seat with adhesive, the connector seat has a ring-shaped projection with an external diameter less than an internal diameter of a lower chamber of the positive pressure housing at a center of the upper end of the connector seat, the lower end of the silicone stopper is adhered to the internal circumference surface of the ring-shaped projection, balancing holes are defined in the ring-shaped projection and communicates with air, a lower end of the connector seat is a Luer taper joint, the Luer taper joint has a conical tube, connecting to an additional connector at a central portion thereof, and a plurality of radial guide holes are defined between the ring-shaped projection and an upper end of the conical tube.
2. The multifunction indwelling needle of claim 1, wherein the anti-backflow valve comprises a tubular body and a wedge portion at a bottom of the tubular body, a middle portion of a bottom of the wedge portion defines a linear gap communicating with an inner hole of the tubular body, a radial flange, which can inserted into a front portion of the hollow chamber of the cannula seat, extends from a top end of the tubular body, a pair of pressing protrusions extend from a middle portion of an outer sidewall of the cannula seat, the pressing protrusions correspond to opposite ends of the linear gap, and the anti-backflow valve and the middle portion of the cannula seat are made of elastic material.
3. The multifunction indwelling needle of claim 1 or 2, wherein the anti-needle-stick-injures safety mechanism comprises a core rod, a multi-stage retractable sleeve, and a ferrule, the needle seat is substantially a tube with a closed top end, a top end of the core rod is connected to an axial center of the needle seat, a lower end of the core rod is connected to a distal end of the needle, a flange of the lower end of the core rod inserts into an opening of a top end of a first stage retractable sleeve, a flange of a lower end of a second stage retractable sleeve inserts into an opening of a top end of a neighboring outer stage retractable sleeve, a lower end of the outermost stage retractable sleeve is connected to the ferrule, an outer surface of the ferrule is inserted into an opening at a lower end of the needle seat, an axial center of the ferrule defines a through hole for passing the needle, and the needle entirely enters the multi-stage retractable sleeve after both of the two stage retractable sleeves are pulled out of the needle seat by pulling the ferrule.
4. The multifunction indwelling needle of claim 3, wherein an elastic eccentric cone is assembled inside the ferrule, a slanted through hole is defined in the eccentric cone and extends from a bottom center to a top point of the eccentric cone, a diameter of the slanted through hole is slightly larger than an external diameter of the needle, the top point of the eccentric cone faces one side of the needle, and a bottom of the eccentric cone is coupled with an opening of the ferrule.
5. The multifunction indwelling needle of claim 3 or 4, wherein the ferrule is coupled with the cannula seat through a fast detachable structure.
6. The multifunction indwelling needle of claim 5, wherein the fast detachable structure comprises a cylinder arranged in a center of the ferrule, the cylinder defines a through hole for passing the needle at a central portion of the cylinder, the external diameter of the cylinder match the dimension of a distal end of the cannula seat, and the cylinder is embedded in the cannula seat and is coupled with a distal end of the cannula seat by over fitting.
7. The multifunction indwelling needle of claim 5, wherein the fast detachable structure comprises a pair of clamps at a front portion of the ferrule, and the distal end of the cannula seat defines engagement grooved corresponding to the clamps.