CN113975483B

CN113975483B - Syringe for joint cavity

Info

Publication number: CN113975483B
Application number: CN202111292945.1A
Authority: CN
Inventors: 祁荷栩; 方婕; 赵志河; 吴楠
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2021-11-03
Filing date: 2021-11-03
Publication date: 2022-05-13
Anticipated expiration: 2041-11-03
Also published as: CN113975483A

Abstract

An injector for a joint cavity comprises a needle cylinder and an outer needle, wherein an inner needle capable of sliding relative to the outer needle is arranged in the outer needle, and the inner needle is made of a flexible material; the syringe also comprises a control mechanism, the control mechanism is used for controlling the syringe to be switched to a needle outlet state or a needle retracting state, the bottom end of the inner needle head extends to the outside of the outer needle head in the needle outlet state, and the bottom end of the inner needle head retracts to the inside of the outer needle head in the needle retracting state. The flexible inner needle is used for searching and positioning the position in the joint cavity, after the flexible inner needle is contacted with surrounding tissues, the inner needle can change the direction of the inner needle by utilizing deformation, the damage of the needle to articular cartilage and blood vessels is effectively reduced, the flexible material of the inner needle avoids needle breakage fundamentally, the safety is obviously improved, in addition, the inner needle can be better attached to a complex structure in the joint cavity, the effusion in the joint cavity is further extracted more fully, and the effusion extraction effect of the injector is improved.

Description

Syringe for joint cavity

Technical Field

The invention relates to the technical field of medical instruments, in particular to an injector for joint cavities.

Background

Joint puncture is the use of a syringe to inject liquid medicine into the joint cavity or to withdraw effusion from the joint cavity to assist in diagnosis and treatment of joint diseases. The difficulty of needle insertion is high due to the narrow volume and complex structure of the lower cavity of the mandibular joint and the joint cavity of the palm, wrist and finger, joint cartilage and blood vessels are easily damaged by carelessness depending on the experience of doctors, and complications such as hematoma, hemarthrosis, suppurative arthritis and the like are caused at the puncture part.

In order to reduce the operation difficulty in the narrow joint cavity, improve the operation safety and relieve the pain of a patient, injectors with different structures are designed according to the characteristics of different joint cavities in the prior art. Patent CN208552827U discloses a special needle suitable for palm wrist finger joint chamber, and this special needle includes distal end needle body and near-end needle body, forms the dog-ear that has certain angle before distal end needle body and the near-end needle body, and the setting of dog-ear accords with joint clearance angle more, can reduce the probability of accidental injury articular cartilage.

However, the special injector in the prior art only aims at a specific joint cavity, and the applicable joint cavity types are few. More importantly, the current special syringe adopts a bent and thinner needle head, although the needle head can be better attached to the joint gap, hematoma caused by puncturing the blood vessel is avoided, the needle head is easy to break the needle, the operation experience and the manipulation of doctors are also highly required, once the puncture angle is wrong, the injury of parts such as articular cartilage, blood vessel and the like can still be caused, in addition, after puncture, in order to reduce pain and injury, the position of the needle head in the joint cavity is basically fixed, and the effusion in the joint cavity cannot be effectively extracted.

Disclosure of Invention

The invention aims to provide an injector for a joint cavity, and aims to solve the problems that the injector in the prior art is low in universality, a bent and thin needle head is easy to break, articular cartilage and blood vessels are easy to damage, and effusion in the joint cavity cannot be effectively extracted.

The invention is realized by the following technical scheme:

an injector for an articular cavity comprises a needle cylinder and an outer needle connected with the needle cylinder, wherein an inner needle capable of sliding relative to the outer needle is arranged in the outer needle, and the inner needle is made of flexible materials; the syringe still includes control mechanism, control mechanism is used for controlling the syringe switches over to a state or the state of narrowing of the needle go out under the state of the needle, the bottom of interior syringe needle extends to outside the syringe needle, under the state of narrowing of the needle, the bottom of interior syringe needle is withdrawed to inside the outer syringe needle.

In this technical solution, as in the prior art, the injector comprises a needle cylinder and an outer needle for insertion into the joint cavity. Different from the prior art, the outer needle head is also internally provided with an inner needle head, and the inner needle head can move relatively to the outer needle head. The inner needle is made of a flexible material, preferably rubber, and in some embodiments, the inner needle is made of medical silicone rubber.

The injector also includes a control mechanism which may be a separate component that is in or out of contact with the barrel, needle, or may be an integral component mounted to the barrel and/or needle. The control mechanism is used for a doctor to operate the inner needle head so as to push the bottom end of the inner needle head to move into or out of the outer needle head, and therefore the injector is switched between a needle retracting state and a needle withdrawing state.

During the use, through the vertical downstream of needle in control mechanism control, when interior needle bottom extends out outer needle, the syringe gets into out the needle state, the bottom of interior needle this moment is less than the bottom of outer needle, thereby make interior needle replace outer needle to carry out the exploration of joint intracavity position, flexible material of needle meets when hindering in the positioning process will produce certain deformation, avoid stabbing surrounding tissue, including the needle remove to the assigned position and accomplish extraction hydrops or injection liquid medicine operation after, through the vertical rebound of needle in control mechanism control, with interior needle bottom income outer needle, the syringe gets into the state of narrowing, under the state of narrowing, outer needle can puncture and get into the joint intracavity.

Through the aforesaid setting, flexible interior syringe needle replaces outer syringe needle to carry out the position exploration in the joint chamber, fix a position, with the tissue contact back on every side, interior syringe needle can utilize deformation to change self orientation, and then reduce the syringe needle to articular cartilage effectively, vascular damage, simultaneously, the flexible material of interior syringe needle has avoided disconnected needle from the root, the security has been improved remarkably, patient's pain has been reduced, in addition, interior syringe needle can laminate the complicated structure in the joint chamber better, and then extract the hydrops in the joint chamber more fully, the hydrops extraction effect of syringe has been improved.

The control mechanism of the injector has various realization modes, can remotely control the movement of the inner needle head through a control terminal, and can also control the up-and-down movement of the inner needle head through manual mechanical transmission.

As a preferred embodiment of the control mechanism in the present invention, the control mechanism includes a control cylinder sleeved outside the outer needle, the control cylinder is provided with a sliding groove, a control rod is slidably disposed in the sliding groove, the outer needle is provided with an opening, the control rod movably passes through the opening and is connected to the outer wall of the inner needle, and the control rod is used for driving the inner needle to move along a vertical direction.

In this technical scheme, on the outer wall of outer syringe needle was located to the control cylinder cover, be provided with spout, opening on the control cylinder, the outer syringe needle respectively to the control lever activity runs through both, and can follow both vertical reciprocates. Preferably, the chute and the opening are both vertical strip-like structures.

Control lever one end is located the outside of a control section of thick bamboo to in doctor's promotion operation, the control lever other end is connected to on the outer wall of interior syringe needle, with interior syringe needle synchronous motion, and then makes the doctor's accessible observe the position of control lever in the spout and judge the present depth of visiting down of interior syringe needle. The control mechanism simple structure, the operation of being convenient for that this technical scheme provided, the syringe can be received a needle fast and move to the appointed degree of depth with going out the needle.

As another preferred embodiment of the control mechanism in the present invention, the control mechanism includes a control cylinder sleeved outside the outer needle, the control cylinder is provided with a rotating member, one end of the rotating member located inside the control cylinder is provided with a gear, the outer needle is provided with an opening, a push rod connected to an outer wall of the inner needle is slidably disposed in the opening, the push rod is connected to a transmission rod, the transmission rod is provided with a rack, and the rack is engaged with the gear.

In the technical scheme, the control cylinder is sleeved on the outer wall of the outer needle head, one end of a rotating piece movably penetrating through the wall surface of the control cylinder is located on the outer side of the control cylinder and used for doctor operation, the other end of the rotating piece is located in the control cylinder, and a gear is arranged on the outer wall of one end of the rotating piece located on the control cylinder.

The outer needle head is provided with an opening, the opening has a similar effect with the sliding groove, and a push rod capable of sliding up and down along the opening is arranged in the opening in a sliding manner. One end of the push rod is connected with the outer wall of the inner needle head so as to realize the synchronous movement of the push rod and the inner needle head, the other end of the push rod, which is positioned in the control cylinder, is provided with a transmission rod, and the transmission rod is provided with a rack which is meshed with the gear.

During control, the rotating part rotates clockwise or anticlockwise, the gear can be driven, the transmission rod is driven to move upwards or downwards along the vertical direction through the meshing of the gear and the rack, the push rod and the inner needle head are driven to move up and down along the vertical direction, and needle retracting or needle withdrawing of the injector is achieved.

In the technical scheme, the downward probing depth of the inner needle head can be judged through the number of turns of the rotating member, the control system can further realize fine adjustment of the downward probing depth of the inner needle head, the inner needle head can be more accurately downward probed to the specified position in the joint cavity, and the inner needle head positioned in the joint cavity can also be gradually deformed in the downward probing process, so that the orientation of the inner needle head can be adjusted, and surrounding tissues are prevented from being damaged; meanwhile, the meshing of the rack and the gear can also reduce the backspacing of the transmission rod in the downward detection process, so that the reliability of the control system is higher; moreover, because the control cylinder is not provided with the sliding groove, the whole control cylinder is of a closed structure, has better air tightness and is beneficial to effusion extraction and liquid medicine injection.

Furthermore, a traction rope is connected to the bottom end of the inner needle head and penetrates out of the control cylinder. Among this technical scheme, the bottom of syringe needle in the haulage rope one end is connected, and the other end is worn out by a control section of thick bamboo and is convenient for the user to drag or the propelling movement, and then allows the user through operation haulage rope to the orientation of syringe needle bottom in the adjustment. In the spy in-process down, appear articular cartilage on the moving path of interior syringe needle, when blood vessel, although interior syringe needle can utilize self deformation to reduce the damage to surrounding tissue, nevertheless because the joint intracavity is small in size, it is complicated, still certain probability damages to surrounding tissue, through drawing the area or propelling movement haulage rope, can increase the deformation of interior syringe needle bottom according to user's intention, not only make interior syringe needle walk around surrounding tissue better, further reduce the damage, but also can be simultaneously at the degree of depth, towards two dimension adjustment interior syringe needles, allow interior syringe needle more to laminate the assigned position, extract the hydrops fully.

Furthermore, a traction ring positioned inside the inner needle head is arranged at the bottom end of the inner needle head, and the traction rope is connected to the traction ring. In the technical scheme, the traction ring is arranged in the inner needle head and is of an annular structure with certain rigidity and elasticity, and the traction ring is mainly used for keeping the annular structure at the bottom end of the inner needle head, so that the opening area at the bottom end is obviously reduced or closed in the process of pulling or pushing the traction rope, and the injection or extraction is not smooth.

Further, an elastic sealing element is arranged in the opening, and the control rod or the push rod penetrates through the elastic sealing element. Among this technical scheme, elastic sealing element covers whole opening, and control lever or push rod insert to elastic sealing element, when control lever or push rod remove along vertical direction, elastic sealing element produces certain deformation, allows control lever or push rod to reciprocate a section distance along the opening, and in the control lever scheme, along with the increase of spy degree of depth down, elastic sealing element increases the reaction force of control lever, feeds back to the user hand, can remind the current spy degree of depth down of user. Meanwhile, the elastic sealing element can effectively improve the air tightness of the opening, and further improves the extraction and injection effects.

As a preferable structure of the invention, the outer needle head is detachably connected with the needle cylinder. Specifically, an outer connecting cylinder is arranged at the upper end of the outer needle head, an inner connecting cylinder is arranged in the outer connecting cylinder, a gap is formed between the outer connecting cylinder and the inner connecting cylinder, the upper end of the inner connecting cylinder penetrates through the top of the outer connecting cylinder to form an access port for accessing a squeezing cylinder of a needle cylinder, and the lower end of the inner connecting cylinder penetrates through the bottom of the inner connecting cylinder and is communicated with the interior of the outer needle head; a partition plate is arranged in the inner connecting cylinder, a spring is arranged on the partition plate, the upper end of the spring is connected with a plugging piece, and a second through hole and a third through hole are further formed in the wall surface of the inner connecting cylinder, wherein the second through hole is located above the partition plate, and the third through hole is located below the partition plate; a first through hole is formed in the side wall of the extrusion cylinder of the needle head, when the needle head is mounted on the outer connecting cylinder, the extrusion cylinder is inserted into the access port and extrudes the plugging piece, the spring is compressed, and the first through hole is communicated with the second through hole; when the needle head is taken down from the outer connecting cylinder, the plugging piece resets under the action of the spring, and the plugging piece seals the second through hole.

In the technical scheme, the outer needle head is connected with the needle cylinder through the connecting cylinder. Wherein, the connecting cylinder includes outer connecting cylinder and the interior connecting cylinder that is located outer connecting cylinder, has the clearance between the interior connecting cylinder of inside and outside, and this clearance is used for injection or hydrops circulation. The upper and lower both ends of an internal connection section of thick bamboo run through the top surface and the bottom surface of outer connecting cylinder respectively, and wherein, the upper end of an internal connection section of thick bamboo runs through and forms the access mouth behind the top surface, should insert the recipient that the mouth is used for putting into the cylinder, and the lower extreme of an internal connection section of thick bamboo runs through behind the bottom surface promptly with the inside intercommunication of syringe needle.

Be provided with the baffle in the inner connecting cylinder, be connected with the spring on the baffle, the shutoff piece of connecting on the spring can reciprocate in the inner connecting cylinder under the effect of spring, recipient, and two parts about the setting of baffle, shutoff piece divide into the inner connecting cylinder for injection, hydrops can not direct flow through the upper and lower both ends of inner connecting cylinder. The upper part of the inner connecting cylinder is provided with a second through hole, the second through hole is positioned on the wall surface of the inner connecting cylinder, the lower part of the inner connecting cylinder is provided with a third through hole, and the third through hole is positioned on the wall surface of the inner connecting cylinder.

The bottom of cylinder is provided with the recipient, first through-hole has been seted up on the wall of recipient, make the recipient impress completely and insert the mouth after, the vertical downstream of shutoff piece is to forming the lower limit, spring compression this moment, first through-hole and second through-hole intercommunication, the injection can be under the impetus of cylinder piston, from the cylinder in, in proper order through the recipient, first through-hole, the second through-hole, the clearance of inside and outside connecting cylinder, the third through-hole, outer syringe needle, interior syringe needle injection to the joint intracavity, and the same reason, also can be through above-mentioned parts, reverse extraction hydrops from the joint intracavity.

When injection of injection liquid of the needle cylinder is finished and the needle cylinder needs to be replaced, the original needle cylinder is taken down from the connecting cylinder, after pressure exerted on the plugging piece by the extrusion cylinder is removed, the plugging piece resets under the action of the spring, and the reset plugging piece closes the second through hole, so that the gap is isolated from the external space, and the relative sterility of the needle head environment is ensured; after the new needle cylinder is inserted into the extrusion cylinder, the plugging piece is pressed down again, and after the first through hole and the second through hole are communicated, the injection in the new needle cylinder can be continuously injected into the joint cavity.

Through the aforesaid setting, when changing the cylinder, syringe needle part is located the joint chamber all the time, can reduce to puncture repeatedly to the joint irritate effectively, reduce joint chamber infection probability, simultaneously, utilize the elastic force of spring, when the recipient pops out from the access mouth, the shutoff piece can block off the second through-hole rapidly, keep the aseptic in clearance, in addition, injection and hydrops all need flow through the second through-hole that is located on the interior connecting tube wall, the third through-hole, compare in the upper and lower both ends of direct flow through interior connecting tube, the recoil of hydrops when can avoiding having the pressure differential effectively.

Further, the bottom surface of the needle cylinder is provided with a connecting piece, and the connecting piece is in threaded connection with the outer connecting cylinder. The connecting piece is preferably of a cylindrical structure, an internal thread or an external thread is arranged on the inner wall of the connecting piece, and a matched external thread or an internal thread is arranged on the outer wall of the outer connecting cylinder, so that the connecting piece and the outer connecting cylinder are tightly connected together through threaded connection.

Furthermore, the outer needle head is provided with scale marks. The scale marks enable the depth of the needle insertion to be directly visible, and the inaccurate position caused by too shallow needle insertion and the damage of deep tissues, articular cartilage and the like caused by too deep needle insertion are avoided.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. according to the invention, the flexible inner needle is used for replacing the outer needle to search and position the position in the joint cavity, after the flexible inner needle is contacted with surrounding tissues, the inner needle can change the direction of the inner needle by utilizing deformation, so that the damage of the needle to articular cartilage and blood vessels is effectively reduced, meanwhile, the flexible material of the inner needle avoids needle breakage fundamentally, the safety is obviously improved, the pain of a patient is reduced, in addition, the inner needle can be better attached to a complex structure in the joint cavity, the effusion in the joint cavity is more fully extracted, and the effusion extraction effect of the syringe is improved;

2. the control mechanism drives the inner needle head to synchronously move up and down through the control rod, the structure is simple, the operation is convenient, and the injector can quickly retract and withdraw the needle to a specified depth;

3. the other control mechanism can realize fine adjustment of the downward probing depth of the inner needle head, the inner needle head is more accurately downward probed to the designated position in the joint cavity, the inner needle head positioned in the joint cavity can be gradually deformed in the downward probing process, the orientation of the inner needle head is adjusted, and surrounding tissues are prevented from being damaged; meanwhile, the meshing of the rack and the gear can also reduce the backspacing of the transmission rod in the downward detection process, so that the reliability of the control system is higher; moreover, as the control cylinder is not provided with the sliding groove, the whole control cylinder has a closed structure, has better air tightness and is beneficial to effusion extraction and liquid medicine injection;

4. the invention utilizes the traction rope and the traction ring to allow a user to increase the deformation of the bottom end of the inner needle according to the intention of the user, so that the inner needle can better bypass the surrounding tissues and further reduce the damage, and the inner needle can be adjusted in two dimensions of depth and direction at the same time, so that the inner needle is allowed to be more attached to the designated position and the effusion is fully extracted;

5. the needle cylinder and the needle head are detachably connected, when the needle cylinder is replaced, the needle head part is always positioned in the joint cavity, the irritation of repeated puncture to the joint can be effectively reduced, the infection probability of the joint cavity is reduced, meanwhile, the blocking piece can rapidly block the second through hole by utilizing the elastic force of the spring when the extrusion cylinder is ejected from the access opening, the sterility of a gap is kept, in addition, injection liquid and effusion both need to flow through the second through hole and the third through hole which are positioned on the wall surface of the inner connecting cylinder, and compared with the situation that the injection liquid and the effusion directly flow through the upper end and the lower end of the inner connecting cylinder, the backflushing of the effusion when pressure difference exists can be effectively avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic view of a syringe constructed in accordance with an embodiment of the present invention in a retracted state;

FIG. 3 is a schematic diagram of a syringe constructed in accordance with an embodiment of the present invention in an extended state;

FIG. 4 is a schematic view of another embodiment of the present invention showing the syringe in a retracted state;

FIG. 5 is an enlarged view of a portion of FIG. 4 at A;

FIG. 6 is a schematic view of a syringe having a barrel and a connector barrel according to yet another configuration in accordance with an embodiment of the present invention;

FIG. 7 is a schematic view of a syringe constructed in accordance with yet another embodiment of the present invention, showing the structure of the connector barrel when the barrel is separated from the connector barrel.

Reference numbers and corresponding part names in the drawings:

1-syringe, 11-connecting piece, 12-extrusion cylinder, 13-first through hole, 2-piston, 3-outer needle, 31-graduation line, 41-control cylinder, 42-inner needle, 43-control rod, 44-sliding chute, 45-elastic sealing element, 46-traction rope, 47-traction ring, 51-rotating piece, 52-gear, 53-transmission rod, 54-rack, 55-push rod, 56-guide ring, 61-outer connecting cylinder, 62-inner connecting cylinder, 63-second through hole, 64-third through hole, 65-clapboard, 66-spring and 67-sealing piece.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

In the description of the present invention, it is to be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore, should not be taken as limiting the scope of the invention.

Example 1:

an injector for articular cavity as shown in fig. 1 to 5 comprises a needle cylinder 1 and an outer needle 3 connected with the needle cylinder 1, wherein an inner needle 42 capable of sliding relative to the outer needle 3 is arranged in the outer needle 3, and the inner needle 42 is made of flexible material;

the syringe further comprises a control mechanism, the control mechanism is used for controlling the syringe to be switched to a needle outlet state or a needle retracting state, the bottom end of the inner needle head 42 extends to the outside of the outer needle head 3 in the needle outlet state, and the bottom end of the inner needle head 42 is retracted to the inside of the outer needle head 3 in the needle retracting state.

In some embodiments, as shown in fig. 1, the outer needle 3 is provided with graduation marks 31.

In one or more embodiments, the inner needle 42 is made of medical grade silicone rubber.

In one or more embodiments, preferably, the outer wall of the inner needle abuts the inner wall of the outer needle.

In this embodiment, the flexible interior syringe needle replaces outer syringe needle to carry out the position exploration in the joint chamber, fix a position, with the tissue contact back on every side, interior syringe needle can utilize deformation to change self orientation, and then reduce the syringe needle to articular cartilage effectively, vascular damage, and simultaneously, the flexible material of interior syringe needle has avoided disconnected needle from the root, the security has been improved remarkably, patient's pain has been reduced, in addition, interior syringe needle can laminate the complicated structure in the joint chamber better, and then extract the hydrops in the joint chamber more fully, the hydrops extraction effect of syringe has been improved.

Example 2:

on the basis of embodiment 1, as shown in fig. 2 and 3, the control mechanism includes a control barrel 41 sleeved outside the outer needle 3, a sliding slot 44 is formed on the control barrel 41, a control rod 43 is slidably disposed in the sliding slot 44, an opening is formed on the outer needle 3, the control rod 43 movably passes through the opening and is connected to an outer wall of the inner needle 42, and the control rod 43 is used for driving the inner needle 42 to move in a vertical direction.

In some embodiments, a pull string 46 is connected to the bottom end of the inner needle 42, and the pull string 46 passes through the control cylinder 41. In the spy in-process down, appear articular cartilage on the moving path of interior syringe needle, when blood vessel, although interior syringe needle can utilize self deformation to reduce the damage to surrounding tissue, nevertheless because the joint intracavity is small in size, it is complicated, still certain probability damages to surrounding tissue, through drawing the area or propelling movement haulage rope, can increase the deformation of interior syringe needle bottom according to user's intention, not only make interior syringe needle walk around surrounding tissue better, further reduce the damage, but also can be simultaneously at the degree of depth, towards two dimension adjustment interior syringe needles, allow interior syringe needle more to laminate the assigned position, extract the hydrops fully.

In one or more embodiments, the pull cord may also exit the wall of the control cylinder. In one embodiment, the pull cord may extend from the control rod.

In some embodiments, the bottom end of the inner needle 42 is provided with a pulling ring 47 inside the inner needle 42, and the pulling rope 46 is connected to the pulling ring 47. In this embodiment, the inner needle is further provided with a traction ring, the traction ring is an annular structure with certain rigidity and elasticity, and the traction ring is mainly used for keeping the annular structure at the bottom end of the inner needle, so that the problem that the opening area at the bottom end is obviously reduced or closed to cause unsmooth injection or extraction in the pulling or pushing process of the traction rope is avoided.

In one or more embodiments, a resilient seal 45 is disposed within the opening, and the control rod 43 or push rod 55 extends through the resilient seal 45. In this embodiment, elastic sealing element not only can improve open-ended gas tightness effectively, further improves extraction and injection effect, and along with the increase of the depth of sounding downwards, elastic sealing element feeds back to the user hand to the reaction force increase of control lever in addition, can remind the current depth of sounding downwards of user.

In some embodiments, the length of the inner needle is configured such that, during the up-and-down movement of the control rod in the sliding chute, the outer wall of the inner needle always covers the opening, i.e. the upper end of the inner needle is always higher than the upper end of the opening, so as to further improve the air tightness of the syringe, facilitate the extraction of effusion and the injection of liquid medicine.

Example 3:

on the basis of embodiment 1, as shown in fig. 4 and 5, the control mechanism includes a control barrel 41 sleeved outside the outer needle 3, a rotating member 51 is disposed on the control barrel 41, a gear 52 is disposed at one end of the rotating member 51 located in the control barrel 41, an opening is disposed on the outer needle 3, a push rod 55 connected to an outer wall of the inner needle 42 is slidably disposed in the opening, a transmission rod 53 is connected to the push rod 55, a rack 54 is disposed on the transmission rod 53, and the rack 54 is engaged with the gear 52.

In the embodiment, the downward probing depth of the inner needle head can be judged through the number of turns of the rotating member, the control system can further realize fine adjustment of the downward probing depth of the inner needle head, the inner needle head can be more accurately downward probed to the specified position in the joint cavity, and the inner needle head positioned in the joint cavity can also be gradually deformed in the downward probing process to adjust the orientation of the inner needle head and avoid damaging surrounding tissues; meanwhile, the meshing of the rack and the gear can also reduce the backspacing of the transmission rod in the downward detection process, so that the reliability of the control system is higher; moreover, because the control cylinder is not provided with the sliding groove, the whole control cylinder is of a closed structure, has better air tightness and is beneficial to effusion extraction and liquid medicine injection.

In some embodiments, the length of the inner needle is configured such that the outer wall of the inner needle always covers the opening during the up and down movement of the push rod in the sliding groove, i.e. the upper end of the inner needle is always higher than the upper end of the opening, so as to improve the air tightness of the syringe.

In some embodiments, as shown in fig. 4 and 5, a guide ring 56 is further disposed on the outer wall of the outer needle, and the inner diameter of the guide ring 56 matches the outer diameter of the transmission rod to allow the transmission rod to move up and down in the guide ring, so as to prevent the transmission rod from disengaging from the gear during the up and down movement, thereby improving the reliability and stability of the control system.

In some embodiments, a pull string 46 is connected to the bottom end of the inner needle 42, and the pull string 46 passes through the control cylinder 41.

In some embodiments, the bottom end of the inner needle 42 is provided with a pulling ring 47 inside the inner needle 42, and the pulling rope 46 is connected to the pulling ring 47.

In one or more embodiments, a resilient seal 45 is disposed within the opening, and the control rod 43 or push rod 55 extends through the resilient seal 45.

Example 4:

on the basis of the above embodiment, as shown in fig. 6 and 7, the upper end of the outer needle 3 is provided with an outer connecting cylinder 61, an inner connecting cylinder 62 is arranged in the outer connecting cylinder 61, a gap is formed between the outer connecting cylinder 61 and the inner connecting cylinder 62, the upper end of the inner connecting cylinder 62 penetrates through the top of the outer connecting cylinder 61 to form an access port for accessing the squeezing barrel 12 of the syringe 1, and the lower end of the inner connecting cylinder 62 penetrates through the bottom of the inner connecting cylinder 61 and is communicated with the inside of the outer needle 3;

a partition plate 65 is arranged in the inner connecting cylinder 61, a spring 66 is arranged on the partition plate 65, the upper end of the spring 66 is connected with a blocking piece 67, and a second through hole 63 positioned above the partition plate 65 and a third through hole 64 positioned below the partition plate 65 are also arranged on the wall surface of the inner connecting cylinder 61;

a first through hole 13 is formed in the side wall of the extrusion cylinder 12 of the needle head 1, when the needle head 1 is mounted on the outer connecting cylinder 61, the extrusion cylinder 12 is inserted into the access port and extrudes the blocking piece 67, the spring 66 is compressed, and the first through hole 13 is communicated with the second through hole 63; when the needle 1 is removed from the outer connecting cylinder 61, the blocking piece 67 is reset under the action of the spring 66, and the second through hole 63 is closed by the blocking piece 67.

As shown in fig. 6 and 7, when the injection of the syringe is completed and the syringe needs to be replaced, the original syringe is taken down from the connecting cylinder, after the pressure exerted on the blocking piece by the extrusion cylinder is removed, the blocking piece is reset under the action of the spring, and the reset blocking piece closes the second through hole, so that the gap is isolated from the external space, and the environment of the needle head is relatively sterile; after a new needle cylinder is inserted into the extrusion cylinder, the plugging piece is pressed down again, after the first through hole and the second through hole are communicated, injection liquid in the new needle cylinder can be injected into the joint cavity from the inside of the needle cylinder through the extrusion cylinder, the first through hole, the second through hole, a gap between the inner connecting cylinder and the outer connecting cylinder, the third through hole, the outer needle head and the inner needle head in sequence under the pushing action of a piston of the needle cylinder.

In this embodiment, when changing the cylinder, syringe needle part is located the joint chamber all the time, can reduce effectively and puncture repeatedly to articular excitement, reduce joint chamber infection probability, simultaneously, utilize the elastic force of spring, when the recipient pops out from the access mouth, the shutoff piece can block off the second through-hole rapidly, keep the aseptic in clearance, in addition, injection and hydrops all need flow through the second through-hole that is located the interior connecting cylinder wall, the third through-hole, compare in the upper and lower both ends of the interior connecting cylinder of direct flow through, the recoil of hydrops when can avoiding having the pressure differential effectively.

In some embodiments, as shown in fig. 6, the bottom surface of the needle cylinder 1 is provided with a connecting member 11, and the connecting member 11 is threadedly coupled to the outer connecting cylinder 61.

The terms "first," "second," and the like, as used herein, are used solely for distinguishing between corresponding parts for the sake of clarity and are not intended to limit any order or to emphasize importance or the like. Further, the term "connected" used herein may be either directly connected or indirectly connected via other components without being particularly described.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. An injector for joint cavity comprises a needle cylinder (1) and an outer needle (3) connected with the needle cylinder (1), and is characterized in that an inner needle (42) capable of sliding relative to the outer needle (3) is arranged in the outer needle (3), and the inner needle (42) is made of flexible material;

the injector further comprises a control mechanism, the control mechanism is used for controlling the injector to be switched to a needle outlet state or a needle retracting state, the bottom end of the inner needle head (42) extends to the outside of the outer needle head (3) in the needle outlet state, and the bottom end of the inner needle head (42) retracts to the inside of the outer needle head (3) in the needle retracting state;

an outer connecting barrel (61) is arranged at the upper end of the outer needle (3), an inner connecting barrel (62) is arranged in the outer connecting barrel (61), a gap is formed between the outer connecting barrel (61) and the inner connecting barrel (62), the upper end of the inner connecting barrel (62) penetrates through the top of the outer connecting barrel (61) to form an access port for accessing a squeezing barrel (12) of a needle cylinder (1), and the lower end of the inner connecting barrel (62) penetrates through the bottom of the inner connecting barrel (62) and is communicated with the interior of the outer needle (3);

a partition plate (65) is arranged in the inner connecting cylinder (62), a spring (66) is arranged on the partition plate (65), the upper end of the spring (66) is connected with a blocking piece (67), and a second through hole (63) positioned above the partition plate (65) and a third through hole (64) positioned below the partition plate (65) are further arranged on the wall surface of the inner connecting cylinder (62);

a first through hole (13) is formed in the side wall of an extrusion cylinder (12) of the needle cylinder (1), when the needle cylinder (1) is installed on the outer connecting cylinder (61), the extrusion cylinder (12) is inserted into the access port and extrudes a plugging piece (67), a spring (66) is compressed, and the first through hole (13) is communicated with the second through hole (63); when the needle cylinder (1) is taken down from the outer connecting cylinder (61), the plugging piece (67) is reset under the action of the spring (66), and the second through hole (63) is sealed by the plugging piece (67).

2. The injector for the joint cavity according to claim 1, wherein the control mechanism comprises a control barrel (41) sleeved outside the outer needle (3), a sliding groove (44) is formed in the control barrel (41), a control rod (43) is slidably arranged in the sliding groove (44), an opening is formed in the outer needle (3), the control rod (43) movably penetrates through the opening and is connected to the outer wall of the inner needle (42), and the control rod (43) is used for driving the inner needle (42) to move along the vertical direction.

3. The injector for the joint cavity according to claim 1, wherein the control mechanism comprises a control barrel (41) sleeved outside the outer needle (3), a rotating member (51) is arranged on the control barrel (41), a gear (52) is arranged at one end of the rotating member (51) positioned in the control barrel (41), an opening is arranged on the outer needle (3), a push rod (55) connected with the outer wall of the inner needle (42) is arranged in the opening in a sliding manner, a transmission rod (53) is connected to the push rod (55), a rack (54) is arranged on the transmission rod (53), and the rack (54) is meshed with the gear (52).

4. An injector for joint cavities according to claim 2 or 3, characterized in that a pull string (46) is connected to the bottom end of the inner needle (42), and the pull string (46) passes through the control cylinder (41).

5. Syringe for articular cavities according to claim 4, characterized in that the bottom end of the inner needle (42) is provided with a traction ring (47) inside the inner needle (42), the traction cord (46) being connected to the traction ring (47).

6. An injector for joint cavities according to claim 2 or 3, characterized in that an elastic seal (45) is arranged in the opening, the control rod (43) or push rod (55) penetrating the elastic seal (45).

7. An injector for articular cavities according to claim 1, characterized in that the bottom surface of the needle cylinder (1) is provided with a connecting piece (11), the connecting piece (11) being screwed with the outer connecting cylinder (61).

8. An injector for articular cavities according to claim 1, characterized in that the outer needle (3) is provided with graduation marks (31).

9. An injector for articular cavities according to claim 1, characterized in that the material of the inner needle (42) is medical silicone rubber.