Medical in-line filter

Abstract

The application discloses a medical built-in filter, which comprises an upper connecting pipe, an outer shell and an inner shell which are sequentially connected through elastic sealing and can be detached; a one-way filtering device is arranged on the inner shell; and a filter membrane is arranged in a cavity formed between the inner shell and the outer shell. The medical built-in filter is provided with the one-way filtering device on the inner shell, and the filter membrane is arranged in the cavity formed between the inner shell and the outer shell, so that a two-layer filtering structure is formed. While preventing liquid backflow, the medical built-in filter can effectively filter liquid medicine twice, filter the chippings and insoluble particles generated by long-term contact between a medical injector and the liquid medicine, block the filtered impurities to prevent the impurities from entering a human body again with the filtrate, and improve the safety and quality controllability of medicine.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical filter, in particular to a medical built-in filter. BACKGROUND

[0002] The drug packaging material refers to the outer packaging material and the medicine filling material which are used for protecting and storing and directly contacting with the medicine, and is referred to as the drug packaging material. The qualified drug packaging material needs to have four basic elements, one is to protect the medicine in the whole process of medicine research and development, production, circulation and use, to prevent the medicine from being affected by factors such as light, absorption / loss of water, reactive gas (oxygen) and microorganism; two is to have good compatibility with the medicine, and there is no interaction between the packaging components and the preparation, so as to cause the quality change of the preparation or the packaging component, including the concentration change caused by the adsorption of the active ingredient or the auxiliary material ingredient of the packaging material, the degradation of the active ingredient caused by the leaching of the packaging material, and the pH change, precipitation, discoloration and the like; three is the safety of the raw material for producing the drug packaging component, which cannot contain substances harmful to human body which can be migrated to the medicine, so the components directly contacting with the medicine need to be focused on; four is the functionality of the drug packaging material, which needs to provide the correct dosage conveniently and accurately.

[0003] The nature of the raw material of the drug packaging material directly contacting with the medicine is an important factor affecting the safety of the medicine and the shelf life of the medicine. For example, the raw materials commonly used in the drug packaging material such as syringes, infusion bags and ampoule bottles are glass, polymer resin, rubber, metal and the like, and can also be composed or combined of two or more materials (such as composite film, aluminum plastic combined cover and the like). After long-term contact with the medicine, the drug packaging material will produce chipping and insoluble particles suspended in the medicine, which has hidden dangers (conventional inspection cannot timely find out) to the quality of the medicine and the human body. Among them, the polymer resin packaging occupies a large proportion in the field of medicine packaging, has the advantages of firm packaging, easy sealing, transparent and beautiful appearance, light weight, convenient carrying, low price and the like, but the degradation products of the polymer resin will migrate to the medicine after long-term contact with the medicine, and there are risks of high temperature, high pressure, ultraviolet radiation and shock in the transportation process, which will accelerate the aging and degradation of the plastic, cause structural changes such as crosslinking or breaking of molecular chain, produce more migration substances, and affect the quality of the medicine. The advantages of glass drug packaging material are transparency, easy sealing, moisture resistance and stable chemical properties, but it is heavy and fragile, and the phenomenon of glass flaking occurs after contacting with the medicine, which migrates to the medicine to form glass debris, which may cause tissue inflammation, damage immune cells and other dangers, and has the hidden danger of blocking blood vessels to form blood clots. In addition to the degradation products and additives of the rubber material of the drug packaging material, rubber particles will also be produced during perforation, and the smaller the particle size, the stronger the penetration ability, which seriously affects the safety and quality controllability of the medicine.

[0004] On the other hand, when intravenous infusion or syringe infusion, often there are bubbles in the liquid, if a large amount of air into the human body in a short time, at this time, the influence of the human heart, a large amount of air in the heart cavity will be stirred, thus a large number of bubbles, when the heart contracts, the bubbles are not discharged, or block the pulmonary artery, which will pose a serious threat to human health, and can even cause sudden death, great harm; If the gas enters the coronary artery of the heart, it is also possible to cause coronary circulation obstruction, which will hinder the heart function of the people, thus threatening the life of the people. Therefore, small bubbles in the liquid should be removed in time during use or treatment, and the pre-filled syringe is a closed structure, and the "residual bubble technology" is currently used. When injecting, no air is discharged directly, and when all the liquid is injected, the small bubbles in the syringe are just filled in the front end of the syringe, which puts forward higher standards and requirements for the production of the syringe and the filling process of the liquid.

[0005] As disclosed in Chinese patent document CN104174101A, a silicon oil free pre-filled syringe only contains a medicine bottle and a luer connector, which can avoid the pollution of silicon oil or other lubricants to the medicine and successfully complete the injection. Although the quality of the liquid in the syringe is not affected by the silicon oil, the migration of the pipe body has no filtering effect.

[0006] Chinese patent document CN105056329A discloses a medicine dissolving device, which comprises a needle seat, a sleeve and a needle, and plays a role in filtering impurities during medicine suction and pushing. However, when the medicine dissolving device performs suction and pushing actions, the impurities are filtered by the filter membrane and remain on the upper side, and are migrated to the liquid again during pushing, which does not substantially filter the impurities in the liquid.

[0007] Chinese patent document CN105708693A discloses an injector filter needle, which is composed of a baffle, a liquid filter membrane arranged on the two side surfaces of the baffle and an elastic one-way valve membrane. The liquid filter membrane is arranged on the side surface of the baffle close to the syringe barrel, and the one-way valve membrane is tightly attached to the other side surface of the baffle and has a plurality of broken lines in the middle. However, the injector filter needle is an external filter, which needs to be removed from the syringe needle during use, and the filter is installed at the connection part between the syringe pipe body and the needle. This may pollute the liquid with particles, bacteria and other impurities in the air, and cause adverse reactions and potential complications during infusion.

[0008] Chinese patent document CN202409629U discloses a breast pump, because different air inlet and air outlet are arranged on the breast pump, the air inlet direction and the air outlet direction do not belong to the same through hole, so that continuous and rapid air inlet and air outlet can be effectively realized, the vacuum generation efficiency in the breast pump cover is fast, and thus the breast pumping effect is improved. However, the device has great limitations when used for medicines, has narrow application range, and cannot realize fine control.

[0009] Chinese patent document CN201267678Y discloses a one-way valve for disposable infusion, comprising a valve seat, a valve cover, and a cutoff diaphragm, a cavity is formed between the valve seat and the valve cover, and the cavity is internally provided with the cutoff diaphragm. When the one-way valve is used for adding medicine, the medicine can be prevented from returning to the drip chamber, so that the medicine can quickly enter the blood and is not diluted by the star. However, the above-mentioned one-way valve is an external medicine filter, and needs to be assembled with other infusion devices in the use process, and has the risk of introducing bacteria and impurities.

[0010] Chinese patent document CN207221116U discloses a cleaning device for obstetrics, comprising a funnel-shaped protective cover, a medicine inlet pipe, a medicine liquid bag, and a sponge. The medicine inlet pipe is internally provided with a one-way flow control valve for controlling the one-way flow of the medicine liquid. The one-way flow control valve comprises a hard baffle and a soft baffle. However, the device has great limitations, has narrow application range, and the one-way flow control valve only prevents liquid backflow and has no filtering effect. SUMMARY

[0011] In view of the problems in the prior art and the direction for improvement, the present application provides a medical built-in filter to solve the problems that most of the existing filters cannot effectively filter impurities, or can only be used as external filters, may introduce bacteria or impurities, and have safety hazards.

[0012] To achieve the above-mentioned purposes, the present application adopts the following technical methods:

[0013] A medical built-in filter comprises an upper connecting pipe, an outer shell, and an inner shell which are sequentially connected by elastic sealing and can be detached.

[0014] The inner shell is provided with a one-way filtering device.

[0015] A filter membrane is arranged in the cavity formed between the inner shell and the outer shell.

[0016] Optionally, the part of the upper connecting pipe that extends into the inner part of the outer shell forms a bubble baffle ring, and a gas storage cavity is formed between the bubble baffle ring, the outer shell, and the filter membrane. In the use process, the bubbles mixed in the medicine liquid will preferentially enter the cavity, avoiding the bubbles entering the body with the medicine liquid.

[0017] Optionally, the one-way filtering device comprises a liquid channel and an elastic one-way valve for controlling the flow direction of the liquid channel; preferably, the elastic one-way valve comprises a circular baffle and a groove matched with the circular baffle (when closed, the circular baffle is placed in the groove on the inner shell), and the cross-sectional radius of the circular baffle is greater than the cross-sectional radius of the liquid channel; the circular baffle is coaxial with the liquid channel.

[0018] The diameter and density of the liquid channel on the inner shell can be adjusted according to actual needs, and each liquid channel is provided with an elastic one-way valve for controlling the flow direction. The one-way filtering device on the inner shell is the first filtering layer, which can filter out impurity particles with a particle size greater than the diameter of the liquid channel. The filter membrane is the second filtering layer in the process of filtering the liquid medicine, and the particle size of the impurity particles to be filtered is smaller than the diameter of the liquid channel. Different filter membranes with different filtering properties can be selected according to actual needs.

[0019] Optionally, the upper connecting pipe is a T-shaped pipe comprising a top pipe body, a cylindrical pipe body and a conical pipe body which are coaxial (the axes are on the same straight line) and are sequentially and sealingly connected, and the inner diameter of the top pipe body is the same as that of the cylindrical pipe body, and the thickness of the top pipe body is greater than that of the cylindrical pipe body, and the protruding part is used for fixing the filter to prevent it from falling off.

[0020] Optionally, the conical pipe body is elastically and sealingly connected with the outer shell.

[0021] Optionally, the top pipe body of the upper connecting pipe is connected with the cylindrical pipe body of the upper connecting pipe by buckling.

[0022] Optionally, the cylindrical pipe body and the conical pipe body are an integral structure, the conical pipe body is a circular truncated cone-shaped cavity with one end large and the other end small, and the inner wall of the circular truncated cone-shaped cavity of the conical pipe body is smoothly connected with the inner wall of the cylindrical pipe body.

[0023] Optionally, the outer shell comprises a top circular ring and a bottom sidewall, and the circular ring is sealingly connected with the sidewall; the filter membrane is fixed in the cavity formed by the outer shell and the inner shell; preferably, the filter membrane is fixed in the cavity formed by the outer shell and the inner shell by a U-shaped support structure; more preferably, the U-shaped support structure is two U-shaped seats, the U-shaped seats are provided with U-shaped hollow cavities, and the two ends of the filter membrane are respectively embedded in the U-shaped hollow cavities of the two U-shaped seats, and the U-shaped support structure is an elastic body.

[0024] Optionally, the connection between the top circular ring of the outer shell and the sidewall is provided with an annular protrusion, and the annular protrusion is located in the cavity formed by the outer shell and the inner shell.

[0025] The inner shell is provided with an elastic sealing ring at the contact position of the bottom side wall of the outer shell;

[0026] The annular protrusion and the elastic sealing ring cooperate to fix the filter membrane and the U-shaped support structure for fixing the filter membrane in the cavity formed between the outer shell and the inner shell, that is, the annular protrusion and the elastic sealing ring are in contact with the surface of the U-shaped support structure, respectively.

[0027] Optionally, the conical tube body is connected with the top circular ring of the outer shell through a threaded structure; preferably, the outer wall of the conical tube body is provided with external threads, and the inner wall of the top circular ring is provided with internal threads, and the internal threads cooperate with the external threads to form a threaded pair.

[0028] Optionally, the height (i.e. the height of the thread) of the external threads and the internal threads is less than the thickness of the conical tube body, and the length of the screwing of the external threads and the internal threads is less than the length of the outer wall generatrix of the conical tube body (i.e. at least containing one tooth of the thread). When the internal threads cooperate with the external threads to form a threaded pair, the tooth top, tooth bottom and tooth side of the thread are all under stress, and the threaded pair itself has sealing ability after screwing, which can prevent the drug solution from flowing out of the thread gap when being extruded. The shape of the external threads and the internal threads is not specifically limited, and conventional shapes such as trapezoidal, rectangular or sawtooth can be used.

[0029] Optionally, the inner shell is an elastic body, and the inner shell is connected with the side wall of the bottom of the outer shell through a buckle sealing connection and fixes the inner shell; preferably, the side wall of the bottom of the outer shell is provided with an annular barb buckle for fixing the inner shell, and the outer diameter of the inner shell cooperates with the inner diameter of the side wall of the outer shell and inserts the inner shell into the inside of the side wall of the outer shell.

[0030] Optionally, the outer wall edge of the top tube body of the upper connecting pipe is provided with two clamping grooves, and the two clamping grooves are symmetrically arranged; the bottom of the side wall of the outer shell is provided with two clamping grooves, and the two clamping grooves are symmetrically arranged. With the help of external tools such as wrenches, the upper connecting pipe and the outer shell are fixed through the two symmetrically arranged clamping grooves, and then the upper connecting pipe and the outer shell are rotated in the direction of threaded assembly, thereby fixing the upper connecting pipe and the outer shell.

[0031] Working principle: as Figure 7As shown, the built-in filter is first placed inside the syringe, and the specific steps are as follows: first, the upper connecting pipe of the built-in filter is placed in the cone head of the syringe, and the protruding part of the upper connecting pipe of the built-in filter is fixed to prevent slipping by using the thickness of the top pipe body being greater than the thickness of the cylindrical pipe body, but the thickness of the protruding part should not exceed the thickness of the needle cylinder cone head of the used syringe. Secondly, the outer shell of the built-in filter is placed through the bottom of the syringe needle cylinder, and the outer shell is rotated by means of external tools such as wrenches through the two symmetrical clamping grooves at the bottom of the side wall of the outer shell, and the upper connecting pipe is rotated by means of external tools such as wrenches through the two symmetrical clamping grooves on the upper connecting pipe, which can be clockwise or counterclockwise. The rotation direction is determined by the screw pair formed by the inner thread on the inner wall of the top ring of the outer shell and the outer thread on the outer wall of the conical pipe body at the bottom of the upper connecting pipe, and then the upper connecting pipe and the outer shell are connected together, and the screw pair is a self-locking structure with sealing function. Finally, the filter membrane and the inner shell are sequentially placed from the bottom of the syringe needle cylinder, and the inner shell is fixed in position by the locking barbs at the bottom of the outer shell to prevent falling off. Thus, the filter is placed inside the syringe.

[0032] After the built-in filter is assembled in the syringe, the drug solution is filled into the needle cylinder of the syringe from the bottom of the syringe needle cylinder. When the syringe push rod is pressed from the bottom to the top of the syringe needle cylinder, the drug solution is pushed out from the needle cylinder to the cone head direction. When the drug solution flows through the filter, the drug solution first acts on the inner shell, and the one-way filter device is opened under the action of atmospheric pressure and the flow force of the drug solution, and the drug solution is preliminarily filtered. Then the drug solution is filtered by the filter membrane for secondary filtration and flows into the upper connecting pipe. The filter membrane can remove smaller impurities and leave them on the side of the filter membrane close to the inner shell. Conversely, when the drug solution on the side of the filter membrane close to the upper connecting pipe enters the needle cylinder from the cone head direction, the one-way filter device on the inner shell is closed under the action of atmospheric pressure and the flow force of the drug solution, preventing the drug solution filled in the syringe from being contaminated.

[0033] Specifically, when the medicine liquid is pushed out from the needle cylinder to the cone head direction, the medicine liquid acts on the inner shell, first enters the liquid passage at the bottom of the inner shell, under the action of atmospheric pressure and the flow force of the medicine liquid, the circular baffle is pushed open, the one-way valve is opened, the liquid passage on the inner shell preliminarily filters the medicine liquid, filters out the impurities with a particle size larger than the diameter of the liquid passage, then the medicine liquid flows into the upper connecting pipe after secondary filtration by the filter membrane, the filter membrane can remove smaller impurities and retain them on the side of the filter membrane close to the inner shell. The medical built-in filter provided by the application adopts two layers of medicine liquid filtering structure to filter the medicine liquid in sequence and retain the filtered impurities away from the upper connecting pipe, so that the impurities do not enter the human body with the medicine liquid, and the medicine liquid is filtered. On the contrary, when the medicine liquid on the side of the filter membrane close to the upper connecting pipe enters the needle cylinder from the cone head direction, under the action of atmospheric pressure and the flow force of the medicine liquid, the circular baffle of the one-way valve on the inner shell is embedded and tightly buckled in the matching groove, and the valve of the one-way valve is closed.

[0034] Compared with the prior art, the medical built-in filter has the following beneficial effects:

[0035] 1. The medical built-in filter provided by the application has the one-way filtering device on the inner shell, and the filter membrane is arranged in the cavity formed between the inner shell and the outer shell, so that two layers of filtering structure are formed, the liquid backflow is prevented, the medicine liquid can be effectively filtered twice, the debris and insoluble particles generated by the long-term contact between the medical injector and the medicine liquid can be filtered, the filtered impurities are prevented from entering the human body again with the filtrate, and the safety and quality controllability of the medicine are improved.

[0036] 2. The medical built-in filter provided by the application has the following advantages: multi-layer filtering, simple structure, reliable connection, convenient installation and removal, etc. The medicine liquid flowing out of the injection cylinder can be filtered, and the filtered impurities are retained in the injection cylinder, which can effectively prevent the insoluble particles in the medicine from polluting the medicine liquid and entering the human body blood circulation with the medicine liquid, and the medicine liquid is substantially filtered. Moreover, the medical built-in filter has low production cost and is convenient to use. The medical built-in filter can be used as part of the injection syringe assembly and matched with the injection syringe and arranged at the medicine liquid outlet, so that the safety of the medicine is effectively ensured and the shelf life of the medicine is effectively prolonged.

[0037] 3. The medical built-in filter provided by the application has the upper connecting pipe extending into the inner part of the outer shell, so that the extending part forms a bubble blocking ring, and the bubble blocking ring, the outer shell and the filter membrane form a gas storage cavity, which can avoid the bubbles in the medicine liquid from entering the human body with the liquid during use and causing harm.

[0038] 4、Pre-filled syringe as the third generation of syringe advantage is that the liquid medicine can be injected into the syringe barrel in advance for storage and transportation, and the syringe is fully sealed before use, which can effectively avoid the pollution of the liquid medicine exposed to the air. The pre-filled syringe mostly uses an integrated needle, which cannot be matched with the existing external filter to filter the liquid medicine. The connection mode of the external filter and the syringe used in the prior art is all nested. If assembled during use, the liquid medicine still cannot avoid contact with air. If assembled as part of the syringe assembly and then used, it is easy to fall off during transportation. Moreover, the external filter is usually separated from the syringe barrel during the injection process of the liquid medicine with high viscosity due to the high internal pressure. The built-in filter provided by the present application tightly connects the syringe barrel and the filter through the sealing pipe thread, effectively avoids the filter falling off, and completely prevents the contact between air and liquid medicine. It is not only suitable for the existing pre-filled syringe, but also suitable for the first generation of glass syringe and the second generation of sterile plastic syringe. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The structure diagram of the medical built-in filter provided by the present application is shown in the figure.

[0040] Figure 2 The sectional view of the medical built-in filter is shown in the figure. Figure 1

[0041] Figure 3 The sectional view of the upper connecting pipe and the outer shell is shown in the figure. Figure 1

[0042] Figure 4 The top view of the inner shell is shown in the figure. Figure 1

[0043] Figure 5 The structure diagram of the liquid channel in the inner shell is shown in the figure. Figure 1

[0044] Figure 6 The diagram of the connection between the circular baffle and the liquid channel in the inner shell is shown in the figure. Figure 1

[0045] The application diagram of the built-in filter provided by the present application in the syringe is shown in the figure. Figure 7

[0046] In the figure:

[0047] ​​​​​1, upper connecting pipe; 2, outer shell; 3, filter membrane; 4, inner shell; 5, built-in filter; 6, syringe; 11, top pipe body; 12, cylindrical pipe body; 13, external thread; 14, bubble blocking ring; 21, circular ring; 22, side wall; 31, U-shaped seat; 41, elastic sealing ring; 42, liquid channel; 61, tapered head; 62, needle cylinder; 63, push rod; 111, clamping groove; 211, internal thread; 212, annular protrusion; 213, gas storage cavity; 221, barb buckle; 222, clamping groove; 421, open end; 422, circular blocking piece; 423, groove; 424, connection. DETAILED DESCRIPTION

[0048] The following detailed description of the embodiments of the present application is given on the premise of the technical solutions of the present application, and detailed implementation manners and processes are given, but the protection scope of the present application is not limited to the following embodiments. The experimental methods not specified in the following embodiments are usually performed according to conventional conditions.

[0049] In the description of the present application, it should be noted that the terms “upper”, “lower”, “inner”, “outer”, “top”, “bottom” and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0050] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the term “connection” should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0051] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0052] As Figures 1-6 shown is a specific embodiment of the medical built-in filter provided by the present application.

[0053] As Figure 1 shown, the medical built-in filter comprises an upper connecting pipe 1, an outer shell 2, a filter membrane 3 and an inner shell 4, and the components are connected through elastic sealing and can be detached, avoiding liquid leakage during filtration, and being convenient to assemble; a one-way filtering device is arranged on the inner shell 4 to prevent backflow of the medicinal liquid; the filter membrane 3 is located in the cavity formed between the inner shell 4 and the outer shell 2.

[0054] The medical built-in filter can filter the liquid medicine twice, prevent the liquid medicine from flowing back, retain the filtered impurities in the syringe, effectively prevent the insoluble particles in the medicine from polluting the liquid medicine and entering the human blood circulation with the liquid medicine, and substantially filter the liquid medicine.

[0055] Specifically, the upper connecting pipe 1 is a T-shaped pipe body, including a top pipe body 11, a cylindrical pipe body 12 and a conical pipe body (not marked in the figure), the top pipe body 11 and the cylindrical pipe body 12 are fixedly connected by buckling.

[0056] Any cross section of the upper connecting pipe 1 is circular, the inner wall cross section diameter of the top pipe body 11 is the same as that of the cylindrical pipe body 12, the thickness of the top pipe body 11 is greater than that of the cylindrical pipe body 12, the protruding part is used for fixing the filter to prevent slipping, but the thickness of the protruding part should not exceed the thickness of the used syringe cone head. The lower end of the cylindrical pipe body 12 is connected with the upper end of the conical pipe body, the conical pipe body is a circular truncated cone cavity with one end large and the other end small, and the inner wall of the circular truncated cone cavity of the conical pipe body is smoothly connected with the inner wall of the cylindrical pipe body 12.

[0057] The outer shell 2 includes a top annular ring 21 and a bottom side wall 22, and the annular ring 21 and the side wall 22 are sealingly connected; the annular ring 21 and the side wall 22 can be an integral structure or can be sealingly connected in other ways.

[0058] The outer wall of the conical pipe body is provided with external threads 13, the inner wall of the top annular ring 21 of the outer shell 2 is provided with internal threads 211, the internal threads 211 and the external threads 13 form a threaded pair to connect the upper connecting pipe 1 and the outer shell 2 together, and the external threads 13 and the internal threads 211 are both trapezoidal single thread (i.e. the protruding tooth shape on the cross section of the thread is trapezoidal, the external threads 13 are a spiral line formed along the outer wall of the conical pipe body, and the internal threads 211 are a spiral line on the outer shell 2 matched with the external threads 13, which can be left-handed or right-handed (for example Figure 3The difference between the large diameter r1 and the small diameter r2 of the thread is less than twice the thickness of the conical tube (i.e. the height of the thread is less than the thickness of the conical tube), the length of the screw thread is less than the length of the outer wall generatrix of the conical tube (i.e. the thread contains one tooth, the more the number of teeth, the better the sealing performance), and the tooth top, tooth bottom and tooth side of the thread are all under stress during operation. The thread pair itself has sealing ability due to the deformation of the thread after screwing, which can prevent the drug solution from flowing out of the thread gap when it is extruded. The upper connecting pipe 1 and the outer shell 2 are connected through the thread structure. During the thread assembly process of the outer thread 13 and the inner thread 211, the two symmetrical clamping grooves 111 provided on the outer wall edge of the top pipe body of the upper connecting pipe 1 and the two clamping grooves 222 symmetrically provided at the bottom end of the side wall 22 of the outer shell 2 are used to fix the upper connecting pipe 1 and the outer shell 2 by means of external tools such as wrenches, etc. and then fixed and connected along the direction of the thread pair formed by the outer thread and the inner thread (as shown in Figure 2

[0059] The part of the conical tube extending into the inner part of the outer shell 2 forms a bubble blocking ring 14, and the bubble blocking ring 14, the outer shell 2 and the filter membrane 3 form a gas storage cavity 213 (as shown in Figure 1 Figure 3 The bubbles flow into the gas storage cavity through the gap between the bubble blocking ring and the filter membrane, and the bubbles mixed with the drug solution during use will preferentially enter the inner part of the gas storage cavity, avoiding the bubbles entering the body with the drug solution.

[0060] The bottom of the side wall 22 of the bottom of the outer shell 2 is provided with an annular barb buckle 221 for fixing the inner shell 4 (as shown in Figure 2 The inner shell 4 is an elastic body, and the outer diameter of the inner shell 4 matches the inner diameter of the side wall 22 of the outer shell 2 and the inner shell 4 is inserted into the inner part of the side wall 22 of the outer shell 2. Specifically, the inner shell 4 is inserted into the inner part of the side wall 22 of the outer shell 2 and fixed by the annular barb buckle 221. When the inner shell is pushed in, the barb is deformed, the sharp end is close to the curved top of the outer shell, and when the bottom edge of the inner shell enters the inner part of the cavity of the outer shell, the barb restores the deformation and fixes the position of the inner shell. The angle of the barb should be appropriate, and when the barb is subjected to the force of the drug solution flowing into the inner part of the injection cylinder from the conical head direction, the barb can support the inner shell and will not move the inner shell into the injection cylinder and separate from the outer shell. The length of the barb should not cover the opening end of the liquid passage on the inner shell to reduce the liquid flow rate.

[0061] ​​The filter membrane 3 is fixed in the cavity between the inner shell 4 and the outer shell 2 by a U-shaped support structure, which is two elastic U-shaped seats 31 with U-shaped hollow cavities. The two ends of the filter membrane 3 are respectively embedded in the U-shaped hollow cavities of the two elastic U-shaped seats 31. The U-shaped hollow cavities are matched with the filter membrane 3, and the opening height and depth of the U-shaped hollow cavities are matched with the cross-sectional diameter of the edge of the filter membrane 3. The two ends of the filter membrane 3 are respectively embedded in the U-shaped hollow cavities of the two elastic U-shaped seats 31.

[0062] The connection between the top circular ring 21 and the side wall 22 of the outer shell 2 is provided with a ring-shaped protrusion 212, and the connection between the bottom side wall 22 of the outer shell 2 and the inner shell 4 is provided with an elastic sealing ring 41. The ring-shaped protrusion 212 and the elastic sealing ring 41 fix the filter membrane 3 and the U-shaped support structure for fixing the filter membrane 3 in the cavity between the outer shell 2 and the inner shell 4. The elastic sealing ring can prevent the drug solution from flowing out of the gap between the filter membrane and the inner side of the outer shell when the drug solution is pressed, and can support the filter membrane structure.

[0063] The one-way filtering device on the inner shell 4 includes a liquid channel 42 (as shown in Figure 4 ), and an elastic one-way valve for controlling the flow direction of the liquid channel 42. The elastic one-way valve includes a circular baffle 422 and a groove 423 matched with the circular baffle 422 (as shown in Figure 5 ). The circular baffle 422 is coaxial with the liquid channel 42, and the cross-sectional radius of the circular baffle 422 is greater than the cross-sectional radius of the liquid channel 422. The liquid channel 422 has an open end 421 and a closed end. The groove 423 is arranged in the inner shell 4 at the closed end of the liquid channel 422, and is matched with the lower edge of the circular baffle 422 to form a connection 424 (as shown in Figure 6 ). The smaller the connection between the circular baffle and the inner shell (i.e. the connection), the easier it is to bend and open when the circular baffle is subjected to the force of the drug solution flowing from the syringe to the needle. In the specific implementation process, the density and size of the liquid channels distributed on the inner shell should be appropriate (the layout density of the liquid channels on the inner shell and the cross-sectional radius of the liquid channels can be adjusted according to actual needs, and each liquid channel corresponds to an elastic one-way valve). The circular baffle is made of an elastic material, and its thickness and elasticity should be appropriate. On the one hand, the circular baffle should be in a completely closed state that cannot allow liquid to flow through when it is not subjected to external force, i.e. the baffle should be embedded and tightly clamped in the groove, and the gap between the contact surface of the baffle and the groove should be very small or even close to zero. On the other hand, the connection should be relatively easy to bend and open to form a gap when the baffle is subjected to the force of the drug solution flowing from the syringe to the needle.

[0064] As Figure 7As shown, when the above-mentioned medical built-in filter 5 is used in cooperation with the syringe 6 for filtering, the built-in filter 5 is assembled in the syringe 6 before the pre-filled liquid in the syringe. Specifically, first, the upper connecting pipe of the built-in filter 5 is put into the syringe cone head 61, and the protruding part of the upper connecting pipe top pipe body with a thickness larger than the thickness of the cylindrical pipe body is used to fix the filter upper connecting pipe to prevent slipping, but the thickness of the protruding part should not exceed the thickness of the syringe needle cylinder cone head. Secondly, the outer shell of the built-in filter is put into the bottom of the syringe needle cylinder 62, and the two symmetric clamping grooves 111 provided on the upper connecting pipe 1 and the two clamping grooves 222 provided at the bottom end of the side wall 22 of the outer shell 2 are used to fix and rotate the upper connecting pipe 1 and the outer shell 2 by means of external tools such as wrenches, and then the upper connecting pipe 1 and the outer shell 2 are fixed and connected, the specific rotation direction is determined by the internal thread on the inner wall of the top ring of the outer shell and the external thread on the outer wall of the conical pipe body at the bottom of the upper connecting pipe, and the screw pair formed by rotation is a self-locking structure with sealing function. Thirdly, the filter membrane containing two U-shaped seats (i.e. the two sections of the filter membrane are respectively embedded in the U-shaped hollow cavities of the two elastic U-shaped seats) is put into the bottom of the syringe needle cylinder, so that the annular protrusion at the connection between the top ring and the side wall of the outer shell and the elastic sealing ring at the contact between the top of the inner shell and the bottom side wall of the outer shell cooperate to fix the filter membrane fixed in the cavity formed between the outer shell and the inner shell. Finally, the inner shell is put into the bottom of the syringe needle cylinder, and the elastic sealing ring is placed at the connection between the bottom side wall of the inner shell and the outer shell, and the position of the inner shell is further fixed by the locking barbs at the bottom of the outer shell to prevent falling. Thus, the filter is placed in the syringe.

[0065] The outer diameter of the cylindrical pipe body is slightly smaller than the inner diameter of the syringe cone head, which can completely fit the cylindrical pipe body with the inner wall of the syringe cone head. The outer diameter of the top ring and the bottom side wall of the outer shell is slightly smaller than the inner diameter of the syringe needle cylinder, which can completely fit the top ring and the bottom side wall of the outer shell with the inner wall of the syringe needle cylinder. Specifically, the specifications of the built-in filter can be adjusted according to the specifications of the syringe used.

[0066] When the medical built-in filter is assembled in the syringe, the medicine is filled into the needle cylinder from the bottom of the syringe. When the plunger 63 is pressed from the bottom of the syringe to the tapered head (the direction of the arrow in the figure), the medicine is pushed out from the needle cylinder to the tapered head. When the medicine flows through the filter, the medicine first acts on the inner shell and enters the opening end of the liquid channel from the bottom of the inner shell. Under the action of the atmospheric pressure and the flow force of the medicine, the circular baffle of the sealing end of the liquid channel is pushed open. The part of the circular baffle that is not connected with the inner shell forms a gap through which the medicine flows out. The one-way valve is opened, and the medicine enters the cavity between the inner shell and the filter membrane. In this process, the channel on the inner shell preliminarily filters the medicine and retains the impurities with a larger particle size on the side of the inner shell close to the syringe. Then, the medicine flows through the filter membrane into the upper connecting pipe. At this time, the filter membrane can filter the impurities with a smaller particle size and retain them on the side of the filter membrane close to the inner shell. The bubbles carried by the medicine can enter the gas storage cavity after passing through the filter membrane, and the bubbles are prevented from entering the upper connecting pipe by the bubble blocking ring to prevent the bubbles from being discharged with the medicine. During the filtering process, the upper elastic sealing ring of the inner shell is tightly attached to the lower surface of the U-shaped support structure, the upper surface of the U-shaped support structure is tightly attached to the top end of the annular protrusion inside the outer shell, the tooth top, tooth bottom and tooth side of the conical pipe thread are all under stress, and the whole filtering device is a sealed structure. The two layers of medicine filtering structures filter the medicine in sequence and retain the filtered impurities away from the upper connecting pipe, so that the impurities do not enter the human body with the medicine, thereby playing a filtering role on the medicine. On the contrary, when the medicine on the side of the filter membrane close to the upper connecting pipe enters the needle cylinder from the tapered head, under the action of the atmospheric pressure and the flow force of the medicine, the circular baffle of the one-way valve of the inner shell is embedded and tightly buckled in the matching groove, the valve of the one-way valve is closed, and the medicine filled in the syringe is prevented from being contaminated.

[0067] Compared with the prior art, the medical built-in filter provided by the application filters the medicine in the syringe by arranging a one-way filtering device on the inner shell, retains the filtered impurities in the syringe, effectively prevents the insoluble particles in the medicine from contaminating the medicine and entering the human blood circulation with the medicine, plays a substantial filtering role on the medicine, has a simple structure, low production cost and convenient use, is suitable for wide promotion in medical units to ensure the safety of medicine use and effectively prolong the shelf life of the medicine.

[0068] The above examples are typical examples listed for detailed description of the technical solutions of the application. The protection scope of the application is subject to the protection scope of the claims and the disclosure content, and is not limited by the described embodiments. Simple replacement or change of the application is still within the protection scope of the application.

Claims

1. A medical built-in filter, characterized in that, It includes an upper connecting pipe, an outer shell, and an inner shell connected in sequence by an elastic seal, and all three components are detachable. The inner shell is equipped with a one-way filter device; A filter membrane is provided in the cavity formed between the inner shell and the outer shell; The upper connecting pipe is a T-shaped pipe, comprising a top pipe body, a cylindrical pipe body, and a conical pipe body that are coaxially and sequentially sealed together. The inner diameter of the top pipe body is the same as the inner diameter of the cylindrical pipe body, and the thickness of the top pipe body is greater than the thickness of the cylindrical pipe body. The portion of the upper connecting pipe extending into the interior of the outer casing forms a bubble retaining ring, and a gas storage cavity is formed between the bubble retaining ring, the outer casing, and the filter membrane.

2. The medical built-in filter as described in claim 1, characterized in that, The one-way filtration device includes a liquid channel and a flexible one-way valve for controlling the flow direction of the liquid channel.

3. The medical built-in filter as described in claim 2, characterized in that, The resilient one-way valve includes a circular baffle and a groove that matches the circular baffle, wherein the cross-sectional radius of the circular baffle is larger than the cross-sectional radius of the liquid channel.

4. The medical built-in filter as described in claim 1, characterized in that, The top tube is connected to the cylindrical tube by a snap fastener; The cylindrical tube and the conical tube are integrally formed, and the inner wall of the conical tube is smoothly connected to the inner wall of the cylindrical tube.

5. The medical built-in filter as described in claim 1, characterized in that, The outer shell includes a top ring and a bottom sidewall, and the top ring and the sidewall are sealed together; the filter membrane is fixed in the cavity formed by the outer shell and the inner shell.

6. The medical built-in filter as described in claim 5, characterized in that, The filter membrane is fixed within the cavity formed by the outer shell and the inner shell by a U-shaped support structure.

7. The medical built-in filter as described in claim 5, characterized in that, The top ring of the outer casing is provided with an annular protrusion at the connection between the side wall and the outer casing. An elastic sealing ring is provided at the connection between the inner shell and the bottom side wall of the outer shell; The annular protrusion cooperates with the elastic sealing ring to fix the filter membrane and the U-shaped support structure used to fix the filter membrane together in the cavity formed between the outer shell and the inner shell.

8. The medical built-in filter as described in claim 5, characterized in that, The conical tube is connected to the top ring of the outer shell by a threaded structure.

9. The medical built-in filter as described in claim 8, characterized in that, The outer wall of the conical tube is provided with an external thread, and the inner wall of the top ring is provided with an internal thread. The internal thread and the external thread cooperate to form a threaded pair.

10. The medical built-in filter as described in claim 5, characterized in that, The inner shell is an elastic body, and the inner shell is connected to the side wall at the bottom of the outer shell by a snap-fit ​​seal, thereby fixing the inner shell.

11. The medical built-in filter as described in claim 6, characterized in that, The U-shaped support structure consists of two U-shaped seats with U-shaped hollow cavities. The two ends of the filter membrane are respectively embedded in the two U-shaped hollow cavities, and the U-shaped support structure is an elastic body.

12. The medical built-in filter as described in claim 9, characterized in that, The height of both the external thread and the internal thread is less than the thickness of the conical tube, and the thread engagement length is less than the generatrix length of the outer wall of the conical tube.

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