Abstract:
Disclosed is a filter needle in which a filter structure is embedded in the inner space of a fixing member of a syringe needle. The filter structure has an inlet and an outlet, each of which functions as a check valve, and an inlet path and an outlet path provided with a filter, wherein the inlet path and the outlet path are formed at the rear end of the filter structure. Thus, when a medicament liquid flows out from the ampoule and injected into a patient, foreign substances, such as powder generated during the opening of an ampoule, which otherwise might be introduced into the main body of a syringe and injected into a patient, are filtered by a filter. The filter needle enables the medicament liquid to be injected into the patient without exchanging the syringe. The filter needle is integrally formed of medical silicone to enable easy assembly and safety during use.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit under 35 U.S.C. §119(a) of Korean patent applications filed on Apr. 8, 2011 in the Korean Intellectual Property Office and assigned Serial numbers 10-2011-0032459 and 10-2011-0032465, and of a Korean patent application filed on Jul. 11, 2011 and assigned Serial number 10-2011-0068521, and of a Korean patent application filed on Oct. 31, 2011 and assigned Serial number 10-2011-0112458, the entire disclosure of each of which is hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a medical filter needle, and more particularly, to a filter needle which is detachably installed to a syringe consisting of a cylinder and a piston in use in order to prevent a fine powder, which is generated from a glass or plastic ampoule, from being injected into a patient when the medicament liquid of the ampoule made of glass or plastic, which is absorbed into the cylinder of the syringe, is injected through a syringe needle. 
     In addition, the present invention is provided for allowing the chemical liquid of the ampoule made of glass or plastic to be easily absorbed into the cylinder of a syringe and to be easily injected into a patient. 
     BACKGROUND 
     In general, a syringe, which includes a syringe body and a syringe needle separably installed to a front end of the syringe body, is used for directly injecting a medicament liquid into a patient in a hospital. Since most patients are contaminated with various viruses replicating in living cells as the smallest microorganisms or germs (bacteria) and specifically pathogenic bacteria harmful to a human body, which are fine single-celled organisms, a disposable syringe is mandatorily used to prevent secondary infection during injection. 
     However, except for solid injection requiring injection distilled water for dissolving the solid injection or diluting water-soluble injection, most of injections used in the disposable syringe are made in a liquid state and contained in glass or plastic ampoules. The injections required to be kept for a long time are made in the form of a solid so as to be dissolved in use and are contained and preserved in ampoules, so the injections are used after being mixed with injection distilled water. 
     Impurity powder, such as glass powder (the particle size of 10˜70 μm) or plastic powder (which is finer than the glass powder), is generated when the ampoule is opened for injection. In this state, when the medicament liquid contained in the ampoule or the mixture of the injection distilled water and the solid injection is sucked into the syringe body by using the needle (which is standardized and, in general, has an outer diameter of 652 μm) of the syringe needle, various powder or impurities generated when opening the ampoule are sucked simultaneously with the medicament liquid and the mixture, so that the powder or impurities may be injected into a human body together with the medicament liquid. 
     Thus, the injected impurities, in particular, glass particles of the injected impurities move along a blood vessel, thereby causing necrosis, lung granuloma, phlebitis and thrombosis. In extreme case, a cancer may be caused. That is, the injected impurities may cause many side effects. 
     Therefore, as shown in  FIGS. 8 and 9 , there has been recently proposed a filter needle including a filter  300  installed in the fixing member  220  for fixing a needle  210  in order to separably install a syringe needle  200  to a front of a syringe, so that the filter  300  may filter impurities such as a glass or plastic powder or an impurity powder generated in opening an ampoule. 
     In this case, if the syringe needle is not exchanged on time, the impurities attached to the filter may be injected into a patient through the syringe needle. 
     Practically, in the medical field, the syringe needle  200 , to which the filter  300  is installed, is used to suck the medicament liquid through the syringe needle into the syringe body  100  having the cylinder  110  and the piston  120 , and then, the syringe needle  200  is replaced with new one to inject the medicament liquid into a patient. 
     However, in this case, the medicament liquid is exposed to air so that the medicament liquid may be oxidized or infected. In addition, this sequence of woks is very complicated to medical workers and makes it difficult to rapidly treat emergency patients. Further, many disposable syringes are used even for one day and plural syringe needles are used at one time of injection, so that medical wastes are exponentially increased, thereby exerting harmful influence on environment. 
     Specifically, these medical syringe wastes must be treated after being separated from general medical wastes, so that the cost for treating the medical waste is increased. 
     SUMMARY 
     Therefore, the present invention provides a filter needle which can filter impurities without exchanging a syringe needle, can be easily assembled to be provided at a low cost, and can disperse an injection pressure to easily perform injection. 
     To this end, the present invention provides a filter structure, which has one-way paths having an inlet and an outlet having a check valve function and installed in a fixing member which is separably installed to a front of a syringe body to fix a needle of a syringe needle, and a filter installed to a front end of the outlet of the filter structure, such that, when a medicament liquid sucked together with impurities is injected into a patient, the medicament liquid is only injected through the outlet while the impurities are being filtered by the filter. 
     Further, the inlet and outlet having the check valve function have a structure capable of complementing the check valve function and allowing the suction and exhaustion to be easily performed while preventing the check valve function from being deteriorated in the suction and exhaustion. 
     In addition, a cross-sectional area of the filter is changed to reduce the pressure when the medicament liquid input through the inlet is injected, so that the pressure is dispersed during the exhaustion (injection). 
     In addition, the filter structure is injection-molded into a single body, so that easy fabrication, precise filtering and product uniformity can be achieved. 
     Further, the filter structure is simplified and the structure of the fixing member separably installed to the front of the syringe body is changed while the needle of the syringe needle is fixed, so that the filter structure is easily fabricated and the pressure is minimized when the medicament liquid is exhausted through the outlet for injection. 
     As described above, according to the present invention, the paths of sucking and exhausting a medicament liquid are separated from each other, so that there is no need to exchange a syringe needle and impurities are filtered by the filter only when exhausting the medicament liquid and there is no concern about the injection of impurities into a patient. In addition, the cross-sectional area of the filter is enlarged, so that the injection can be easily operated. 
     In addition, according to the present invention, the filter structure, to which the filter is installed, is only installed to the fixing member of the syringe needle so that the filter needle can be applied to the existing syringes. Thus, the filter needle can be easily fabricated and assembled at a low cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a closed filter structure according to an embodiment of the present invention. 
         FIG. 2  is a sectional view showing a state that the filter structure of  FIG. 1  is installed to a syringe. 
         FIG. 3  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 1 . 
         FIG. 4  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 1 . 
         FIG. 5  is a perspective view showing a closed filter structure according to another embodiment of the present invention. 
         FIG. 6  is a sectional view showing a state that the filter structure of  FIG. 5  is installed to a syringe. 
         FIG. 7  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 5 . 
         FIG. 8  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 5 . 
         FIG. 9  is a perspective view showing a closed filter structure according to a third embodiment of the present invention. 
         FIG. 10  is a sectional view showing a state that the filter structure of  FIG. 9  is installed to a syringe. 
         FIG. 11  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 9 . 
         FIG. 12  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 9 . 
         FIG. 13  is a perspective view showing an opened filter structure according to an embodiment of the present invention. 
         FIG. 14  is a sectional view showing a state that the filter structure of  FIG. 13  is installed to a syringe. 
         FIG. 15  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 13 . 
         FIG. 16  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 13 . 
         FIG. 17  is a perspective view showing an appearance of the filter structure of  FIG. 13 . 
         FIG. 18  is a perspective view showing a filter structure having an opened inlet path according to a second embodiment of the present invention. 
         FIG. 19  is a sectional view showing a state that the filter structure of  FIG. 18  is installed to a syringe. 
         FIG. 20  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 18 . 
         FIG. 21  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 18 . 
         FIG. 22  is a perspective view showing a filter structure having an opened inlet path according to a third embodiment of the present invention. 
         FIG. 23  is a sectional view showing a state that the filter structure of  FIG. 22  is installed to a syringe. 
         FIG. 24  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 22 . 
         FIG. 25  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 22 . 
         FIG. 26  is a sectional view showing a state the filter assembly of  FIG. 22  is installed in an inner space of a fixing member. 
         FIG. 27  is a sectional view showing a guide groove formed on the inner wall of  FIG. 22 . 
         FIG. 28  is a perspective view showing a filter structure having an opened inlet path according to a fourth embodiment of the present invention. 
         FIG. 29  is a sectional view showing a state that the filter structure of  FIG. 28  is installed to a syringe. 
         FIG. 30  is a view showing a state that a medicament liquid flows into an inlet path of the filter structure of  FIG. 28 . 
         FIG. 31  is a view showing a state that a medicament liquid is exhausted through an outlet path of the filter structure of  FIG. 28 . 
         FIG. 32  is an exploded perspective view showing a state that a needle filter according to the related art is installed to a syringe. 
         FIG. 33  is a sectional view showing an installation state of  FIG. 32 . 
     
    
    
     DETAILED DESCRIPTION 
     A filter needle for a syringe is provided. The syringe includes a syringe needle  200  having a needle  210 , a fixing member  220  for fixing the needle  210  and an inner space  230  formed in the fixing member  220 , and a syringe body  100  having a cylinder  110 , a piston  120  and a front end  130  separably installed in the inner space  230  of the fixing member  220  of the syringe needle  200 . The filter needle includes a filter structure  10  installed in the inner space ( 230 ) of the fixing member ( 220 ) of the syringe needle  200  and including an one-way inlet path ( 13 ) having an inlet ( 11 ) and an one-way outlet path ( 14 ) having an outlet ( 12 ), each of which has a function of a check valve; and a filter ( 20 ) installed in the outlet path ( 14 ) at a rear end of the outlet ( 12 ) to filter a foreign substance, which is input through the inlet ( 11 ) simultaneously together with a medicament liquid, from the medicament liquid such that the medicament liquid is only injected into a patient through the outlet ( 12 ) when injecting the medicament liquid into the patient. 
     Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to accompanying drawings. The same reference numerals will be used to refer to the same elements throughout the drawings. In a description of the embodiment, if the function or the structure related to the disclosure and generally known to those skilled in the art make the subject matter of the disclosure unclear, the details of the function or the structure will be omitted. It should be understood that, although the exemplary embodiment of the present invention is described hereinafter, the technical spirit of the present invention is not limited thereto, and can have various modifications.  FIGS. 1 ,  5 ,  9 ,  13 ,  18 ,  22  and  28  are exploded views showing various types of syringes, each of which has a liquid path.  FIGS. 2 ,  6 ,  10 ,  14 ,  19 ,  23  and  29  are sectional views showing states that a filter needle is installed to a syringe.  FIGS. 3 ,  7 ,  11 ,  15 ,  20 ,  24  and  30  are views showing states that a medicament liquid is sucked through a filter needle.  FIGS. 4 ,  8 ,  12 ,  16 ,  21 ,  25  and  31  are views showing states that a medicament liquid is exhausted through a filter needle. 
     Currently, a general-used syringe includes a syringe body  100  and a syringe needle  200 . The syringe body  100  has a front end  130  protruding in a front direction such that the syringe needle  200  is separably installed a cylinder  110 , in which a piston  120  reciprocates, in the front direction of the cylinder  110 . That is, the syringe needle  200  is separably installed to the front end  130  of the syringe body  100 . The syringe needle  200  includes a needle  210  and a fixing member  220 . The needle  210  is generally formed of a metallic material. The fixing member  220  is integrated with the needle  210  to fix the needle thereto (which is generally formed through an insert injection molding scheme for tight fixing) and has an inner space  230  in which the needle  210  is separably installed to the front end  130  of the syringe body  100 . 
     A filter structure  10  of the present invention applied to the syringe is installed at an inside, that is, in an inner space of the fixing member  220  which fixes the needle  210  of the syringe needle  200  thereto. The front end  130  of the syringe body  100  is installed to a rear end of the filter structure  10  such that the filter structure  10  is prevented from being voluntarily separated from the inner space  230  of the fixing member  220  even when a medicament liquid is sucked through the needle  210 . 
     Further, in the filter needle of the present invention, the filter structure  10 , which is installed in the inner space  230  of the fixing member  220  of the syringe needle  200 , is coupled to be prevented from being voluntarily separated from the inner space  230 . 
     Further, the filter structure  10  of the present invention may include closed inlet and outlet paths  13  and  14  which are separated from each other, and may be tightly closed and installed to an inner wall  230   a  of the fixing member  220  of the syringe needle  200 . Differently, the filter structure  10  may include an opened inlet path  13   a  and the closed outlet path  14  and is tightly closed to the fixing member  220  by a guide groove  230   b  which is formed on the inner wall  230   a  which forms the inner space  230  of the fixing member  220 , so that a closed inlet path may be formed, so the filter structure  10  may be simplified. 
     The filter structure  10  is integrally formed by molding medical silicon which is harmless to a human body and has excellent heat resistance, elasticity and abrasion resistance. 
     Of course, it is possible in the scope of the objects of the present invention to substitute various materials for the medical silicon. 
     In addition, the filter structure  10  installed to the syringe needle  200  has the inlet  11  and the outlet  12  having a check valve function and further, has one-way paths, that are, the inlet and outlet paths  13  and  14  having a predetermined depth in the rear direction of the filter structure  10 . A filter  20  is only installed at a rear end of the outlet  12 , that is, in the outlet path  14 , so that the medicament liquid from which a foreign substance, which is input through the inlet  11  simultaneously together with the medicament liquid, is filtered, is only injected through the outlet  12 . 
     The closed outlet path  14  is provided at the center of the simplified filter structure  10  and the opened inlet path  13   a  having no check valve function is formed at the periphery of the closed outlet path  14 . An inclined film  11   a - 1  folded by a pressure is formed on the rear end of the opened inlet path  13   a . The simplified filter structure  10  is tightly coupled to the inner wall  230   a  which forms the inner space  230  of the fixing member  220  of the syringe needle  200 , so that one-way closed inlet path is formed in the inner wall  230  by the guide groove  230   b  having a predetermined width and depth and the inlet  11   a  having the check valve function is formed at the rear end thereof. 
     Although it is possible to form the filter structure  10  in an assembly type, if taking into consideration economic efficiency or product completion, it is preferable to fabricate the filter structure  10  in an integral type. Thus, the integral type of the filter structure  10  will be described in the embodiment. 
     Further, although the inlet path of the filter structure  10  according to the present invention may be in an open or close type  13  or  13   a , the outlet path  14  must be only in a close type. 
     Hereinafter, a preferable embodiment according to the present invention will be described with reference to accompanying drawings in detail. 
       FIGS. 1 ,  5  and  9  are views showing filter structures having closed inlet and outlet paths independent from each other.  FIGS. 1 ,  5  and  9  are views showing filter structures having a closed outlet path and an opened inlet path.  FIGS. 13 and 18  are views showing filter structures installed in an inner space of a fixing member of a previous syringe needle to have a closed inlet path.  FIGS. 22 and 28  are views showing states that a simplified filter structure is installed to the guide groove formed on the inner wall of forming the inner space of the fixing member of the previous syringe needle so that a closed inlet path is formed.  FIG. 8  is a view showing an inner wall for forming the closed inlet path by coupling the filter structure to the inner wall of forming the inner space of the fixing member according to another embodiment. 
     In addition,  FIGS. 1 and 5  show the outlet path  14  formed at the center of the filter structure  10  and the inlet path  13  formed at a curved periphery of the outlet path  14 . The filter structure  10  depicted in  FIG. 3  has the inlet and outlet paths  13  and  14  formed on the same plane and concentrated to one side. 
     Hereinafter, the structures of the filter structures according to various embodiments will be described in detail. 
     The filter structure  10  of  FIGS. 1 and 5  has the closed outlet path  14  formed at the center and the inlet path  13  formed the curved periphery of the closed outlet path  14 . The inlet path  13  has an inner diameter relatively less than that of the outlet path  14 . The plurality of inlet paths  13  is independent from each other in a closed state. In this case, the inlet paths  13  are spaced apart from each other by a uniform interval if possible, so that, when a medicament liquid is sucked into the syringe body  100 , the pressure generated in the inflow of the medicament liquid becomes uniform, so the medicament liquid is sucked easily and fully without any residual liquid. 
     In addition, the inlet and outlet paths  13  and  14  has a predetermined depth, and the inlet  11  and the outlet  12  having the check valve function are formed at the rear ends of the inlet and outlet paths  13  and  14 . Due to the length of the predetermined depth, in the state that the filter structure  10  is installed in the inner space  230  of the fixing member  220  of the syringe needle  200 , the filter structure  10  does not move, so that the position of the filter structure  10  is not changed (twisted) even by the pressure generated when the medicament liquid flows into and out from the syringe body  100 . 
     In addition, the structures of the inlet  11  and the outlet  12  are symmetrical to each other, arranged on mutually opposite sides, and have the check valve function. 
     In order to implement the check valve function in a simple structure according to the present invention, the inlet  11  and the outlet  12  are formed at the rear ends of the inlet path  13  and the outlet path  14  having the predetermined depths. The inlet  11  and the outlet  12  are formed in a film type having a predetermined thickness. The inlet  11  and the outlet  12  of the film type have cut lines  11   a  and  12   a  such that the inlet  11  and the outlet  12  are maintained in a closed state at ordinary times due to elasticity of the films and are opened through the cut lines  11   a  and  12   a  due to the pressures. 
     The inlet  11  and the outlet  12  of the film type having the cut lines  11   a  and  12   a  have inner curved surfaces  11   c  and  12   c  curved in exhausting directions of the medicament liquid through the inlet  11  or the outlet  12  to concentrate the medicament liquid, so that the cut lines  11   a  and  12   a  are easily opened by instantaneous pressures, so the medicament liquid is easily exhausted. Protruded curved surfaces  11   b  and  12   b  are formed at opposite sides of the inner curved surfaces  11   c  and  12   c  to receive low pressures, so that the medicament liquid is gathered only to either the inlet path  13  or the outlet path  14  which is selected by inflow or outflow, so the check valve function is enhanced and easily implemented and in addition, the inlet  11  and the outlet  12  are enabled to be opened by even a low pressure. 
     In addition, as shown in  FIGS. 1   b  and  2   b , the protruded curved surface  12   b  protruded toward the outside of the outlet  12  of the outlet path  14  is protruded from the center of the fixing member  220  of the syringe needle  200 , so that the medicament liquid is introduced into the inlet path  13  while being naturally dispersed to an outside due to the protruded curved surface  12   b  when the medicament liquid is sucked from an ampoule into the syringe body  100 . As shown in  FIGS. 4 and 8 , the protruded curved surface  11   b  protruded toward the outside of the inlet  11  of the inlet path  13 , so that the medicament liquid is fully exhausted while being naturally dispersed to the outlet path  14  when the medicament liquid is injected into a patient. 
     As shown in  FIG. 5 , the filter  20 , which is used to filter impurities when a medicament liquid is injected into a patient by exhausting the medicament liquid through the outlet  12 , may be formed in a plane  20   a  shape or in a hollow tube body  20   b  depicted  FIG. 1  which is not modified or torn due to the pressure generated in injection. A means may be used to allow the filter  20  to be latched at a predetermined position of the outlet path  14 , but may be variously modified in the scope of the objects of the present invention. 
     When the filter  20  is formed in the tube body  20   b , the protruded tube body is tightly closed to the front end of the syringe body  100 , the filter structure is supported without being sucked when the medicament liquid is sucked. When the filter  20  is formed in the plane shape  20   a , the plane filter  20   a  is fixed by a partition wall  21  made of a solid material such that the plane filter  20   a  is prevented from being twisted. The partition wall  21  extends rearward perpendicularly to the rim of the plane filter  20   a , so that the partition wall  21  protrudes rearward and is support without being sucked by the front end  130  of the syringe body. 
     As shown in  FIGS. 13 and 22 , the partition wall  21  described below has an opening  22  such that the medicament liquid is easily sucked. The partition wall  21  reinforces a thin portion a of forming a boundary between the inlet path  13  and the outlet path  14  of the filter structure  10 . 
     However, when the filter  20  is prepared in the form of a plane plate  20   a , a bottle neck phenomenon occurs so that the pressure is increased. To the contrary, when the filter  20  is prepared in the form of a tubular body  20   b  having a hollow inner space, the pressure is dispersed so that the injection is performed at a low pressure during the injection to a patient. 
     However, when the openings  22  are formed on the partition wall  21  for fixing the filter  20   a  by a predetermined depth and a predetermined interval, the bottle neck phenomenon is relieved even if the filter  20   a  is the plane filter  20   a , so that the injection pressure is reduced. 
     In addition, the filter structure  10  of  FIG. 9  (as well as  FIGS. 10 to 12 ) is integrally formed similarly to that of  FIGS. 1 and 5 , but the inlet path  13  and the outlet path  14  of the filter structure  10  of  FIG. 9  are concentrated to one side, so that it is difficult to allow a medicament liquid to fully flow into the inlet path  13  or exhaust out of the outlet path  14  when the medicament liquid flows into the inlet path  13  or exhausts out of the outlet path  14 . Although the filter structure  10  has a portion requiring a higher pressure, the cut lines  11   a  and  12   a  formed in the inlet  11  and the outlet  12 , the inner curved surfaces  11   c  and  12   c  formed on the inside of the inlet  11  and the outlet  12 , and the protruded curved surfaces  11   b  and  12   b  formed on the outside of the inlet  11  and the outlet  12  simply implement the check valve function of the inlet  11  and the outlet  12 . In addition, since each of the inlet path  13  and the outlet path  14  has a predetermined depth, the location of the filter structure  10  installed in the inner space  230  of the fixing member  220  of the syringe needle  200  is not changed (twisted) even when a pressure is generated by the inflow and outflow of the medicament liquid and the injection can be performed while filtering impurities without exchanging the syringe needle  200 , so that the objects of the present invention can be effectively achieved. 
       FIGS. 13 ,  18 ,  22  and  28  are views showing an opened inlet path  13   a  as the inlet path of the filter structure  10 . A closed inlet path may be implemented by installing the filter structure  10  having the open inlet path to the fixing member  220  of a previous syringe needle  220 . The filter structures of the  FIGS. 13 and 18 , which are installed in the inner space of the fixing member of a previous syringe needle, are implemented in a close type. The filter structures of  FIGS. 22 and 28  are respectively installed on the inner wall which forms the inner space of the fixing member of a previous syringe needle and of which the structure is modified. 
     As shown in  FIGS. 13 and 18 , the closed outlet path  14  is formed at the center of the filter structure  10  having the opened inlet path and the opened inlet path  13   a  is formed at the periphery the closed outlet path  14 . The opened inlet path  13   a  is tightly closed to the inner wall  230   a  of the inner space  230  of the fixing member  220  of the syringe needle  220 , so that the opened inlet path  13   a  is closed. In this case, the opened inlet path  13   a  includes a plurality of opened inlet paths which are independent from each other and formed by pillars  13   b  protruding toward the outer wall of the closed outlet path  14  by a predetermined interval and having a predetermined thickness. At this time, the pillars  13   b  are formed to have the regular interval such that the open inlet paths  113   a  can be kept at the uniform interval, so the pressure generated when the liquid is introduced may be uniform, so that the liquid can be easily introduced. 
     Further, the pillars  13   b  of forming the opened inlet path  13   a  and the closed outlet path  14  have a predetermined depth and the inlet  11   a  and the outlet  12  having the check valve function are formed on the ends of the pillar  13   b  and the closed outlet path  14 . Since the pillars  13   b  of forming the opened inlet path  13   a  and the closed outlet path  14  have the predetermined depth, in the state that the filter structure  10  is installed in the inner space  230  of the fixing member  220  of the syringe needle  200 , the location is prevented from being changed by the pressure generated when a medicament liquid flows in or out. 
     Further, according to the present invention, in order to implement the inlet  11   a  of the opened inlet path  13   a  and the outlet  12  of the closed outlet path having the check valve function in a simple structure, an inclined film  11   a - 1  is formed at a rear end of the opened inlet path  13   a  and the pillar  13   a  is formed on an upper surface of the inclined film  11   a - 1 , so that the inclined film  11   a - 1  is folded to only one side to perform the check valve function. In addition, the pillar  13   b  is supported in the inner space  230  of the fixing member  220  of the syringe needle  200  so that a medical liquid easily flows into the syringe needle  200  while the inclined film  11   a - 1  is easily opened when the medical liquid is input through the opened inlet path  13   a . When the medicament liquid flows out through the closed outlet path  14 , the check valve function of allowing the medicament liquid to flow in one-way direction is perfectly performed by an inclined angle of the inclined film  11   a - 1  and the pillar  13   b.    
     According to the present invention, a width of the inclined film  11   a - 1  protruding toward an outside is longer than a thickness of the pillar  13   b , so that the inclined film  11   a - 1  is easily opened when a medicament liquid flows therein. 
     However, the pillar  13   b  has a thickness equal to a width of the inclined film  11   a - 1  according to a material characteristic and the inclined film  11   a - 1  is folded at only a portion in which the pillar  13   b  is not formed, so that the medicament liquid easily flows therein. 
     As shown in  FIGS. 1 ,  5  and  9 , the outlet  12  formed at the rear end of the outlet path  14  is formed in a shape of a film having a predetermined thickness. The film is prepared in the form of a cut line  12   a , which is opened by the pressure, and the film in the form of the cut line  12   a  allows the outlet  12  to have the inner curved surface  12   c , which is curved in an exhausting (progressing) direction of the medicament liquid, so that the cut line  12   a  is easily opened and the exhaustion is facilitated. In addition, the film in the form of the cut line  12   a  allows the outlet  12  to have the protruded curved surface  12   b  opposite to the inner curved surface  12   c  such that less pressure is applied thereto. Thus, the medicament liquid is primarily concentrated to the opened inlet path  13   a  and the outlet path  14  during injection and exhaustion, so the check valve function is enhanced and the pressure is reduced. 
     In addition, as shown in  FIGS. 15 ,  16 ,  20  and  21 , the protruded curved surface  12   b  protruded to an outside of the outlet  12  of the outlet path  14  is placed at the center of the fixing member  220  of the syringe needle  200 , so that the medicament liquid is naturally dispersed to an outside due to the protruded curved surface  12   b  when the medicament liquid is sucked into the syringe body  100 , so the medicament liquid is input to the opened inlet path  13   a . As shown in  FIGS. 15 ,  16 ,  20  and  21 , when the medicament liquid flows into the opened inlet path  13   a , the inclined film  11   a - 1  is folded to the inside. Then, when the medicament liquid is injected to a patient, while the inclined film  11   a - 1  is opened to the outside, the medicament liquid is naturally concentrated onto the closed outlet path  14  due to the inclined film  11   a - 2 , so that the medicament liquid is fully exhausted. 
     As shown in  FIG. 13 , the filter  20 , which is used to filter impurities when a medicament liquid is injected into a patient by exhausting the medicament liquid through the outlet  12 , may be prepared in the form of a plane filter  20   a  as depicted in  FIG. 13  or a hollow tubular body  20   b  as depicted in  FIG. 18 . The filter  18  is not deformed or torn even if the pressure is applied thereto during the injection. A device may be used to allow the filter  20  to be latched at a predetermined position of the outlet path  14 , and the above elements may be variously modified within the scope of the objects of the present invention. 
     However, when the filter  20  is prepared in the form of the plane filter  20   a , a bottle neck phenomenon occurs so that the pressure is increased. To the contrary, when the filter  20  is prepared in the form of the tubular body  20   b , the pressure is dispersed so that the injection is performed at a low pressure during the injection to a patient. 
     As shown in  FIG. 13 , the partition wall  21  for fixing the plane filter  20   a  has the opening  22  such that the medicament liquid is easily sucked. The partition wall  21  reinforces a thin portion a of forming a boundary between the inlet path  13  and the outlet path  14  of the filter structure  10 . When the openings  22  are formed on the partition wall  21  for fixing the filter  20   a  by a predetermined depth and a predetermined interval, the bottle neck phenomenon is relieved even if the filter  20   a  is the plane filter  20   a , so that the injection pressure is reduced similarly with the case in which the filter is the tubular filter  20   b  as shown in  FIG. 5 . 
       FIGS. 22 and 28  are views showing a filter structure  10  which is installed in the inner wall  230   a  which is modified in the structure and in which the inner space  230  of the fixing member  220  of the previous syringe needle  200 , so that the filter structure  10  is simplified and the inflow pressure is reduced. The filter structure  10  includes the closed outlet path  14  formed at the center thereof, the outlet  12  having the check valve function at the rear end of the outlet path  14 , and the opened inlet path  13   a  formed on the curved periphery. As shown in  FIGS. 26 and 27 , the opened inlet path  13   a  is closely installed to the inner wall  230  which forms the inner space  230  of the fixing member  220  of the syringe needle  200 , so that the closed inlet path is formed by the guide groove  230   b  formed on the inner wall. 
     To this end, the guide groove  230   b  is vertically formed on the inner wall  230   a  of forming the inner space  230  of the fixing member  220  at a predetermined depth, so that the opened inlet path  13   a  is converted into the closed inlet path by the guide groove  230   b.    
     If possible, the guide grooves  230   b  are formed to have the predetermined depth and the predetermined interval in such a manner that the pressure, which is generated when a medicament liquid flows into the syringe body  100  in a state that the closed inlet path is formed, is uniformly formed so that the injection is facilitated. 
     In addition, the inner wall  230   a , in which the guide groove  230   b  is formed and the inner space of the fixing member  220  of the filter structure of forming the opened inlet path  13   a  is formed the inner space, is tightly closed to the outer wall of the filter structure  10 , so that the closed inlet path is formed. The guide groove  230   b  is formed while passing through the step protrusions  240  and  240   a  formed in the inner wall of forming the inner space of the fixing member, and the inlet  11   a  having the check valve function is formed to be operated in only inflow while the top surface of the inclined film  11   a - 1  is being latched to the low end of the step protrusion  240   a.    
     In addition, since the guide groove  230   b  and the outlet path  14 , which convert the opened inlet path  13   a  into the closed inlet path, has the predetermined depth, the location of the filter structure  10  installed in the inner space  230  of the fixing member  220  of the syringe needle  200  is not changed even when a pressure is generated by the injection and exhaustion of the medicament liquid. 
     Further, according to the present invention, in order to implement the inlet  11   a  of the opened inlet path  13   a  and the outlet  12  of the closed outlet path having the check valve function in a simple structure, an inclined film  11   a - 1  protrudes from a rear end of the opened inlet path  13   a  in an annular rim shape and the upper surface of the inclined film  11   a - 1  is supported by the low end, that is, the step protrusion  240   a  of the guide groove  13   c  introduced into the inner wall  230   a  that forms the inner space  230  of the fixing member  220  and an upper surface of the inclined film  11   a - 1 , so that the inclined film  11   a - 1  is folded to only one side to perform the check valve function. At the same time, the inclined film  11   a - 1  is supported at the low end of the stop protrusion  240   a  of the guide groove  230   b  formed in the inner wall  230   a  of the inner space of the fixing member  220  of the syringe needle  200 , so that so the medicament liquid easily flows in the syringe body while the inclined film  11   a - 1  is being smoothly folded when a medicament liquid flows in the syringe body. 
     When the medicament liquid flows out through the closed outlet path  14 , the check valve function of allowing the medicament liquid to flow in one-way direction is perfectly performed as an inclined angle of the inclined film  11   a - 1  is compactly supported at the low end (step protrusion  240   a ) of the guide groove  230   b.    
     According to the present invention, the width of the inclined film  11   a - 1  supported by the low end of the guide groove  230   b  is suitably adjusted by taking into consideration the pressure generated when the medicament is exhausted. 
     However, since the width support varies according to a hardness of a material, the width may be variously changed within the scope of the present invention. 
     As shown in  FIGS. 1 ,  5 ,  9 ,  13 ,  18  and  22 , the outlet  12  formed at the rear end of the outlet path  14  is formed in a shape of a film having a predetermined thickness. The film is prepared in the form of a cut line  12   a , which is opened by the pressure, and the film in the form of the cut line  12   a  allows the outlet  12  to be curved in an exhausting (progressing) direction of the medicament liquid, so that the cut line  12   a  is easily opened due to the concentration of pressure and the exhaustion is facilitated. In addition, the film in the form of the cut line  12   a  allows the outlet  12  to have the protruded curved surface  12   b  opposite to the inner curved surface such that less pressure is applied thereto. Thus, the medicament liquid is primarily concentrated to the opened inlet path  13   a  during injection, so the check valve function is enhanced and the pressure is reduced. 
     In addition, as shown in  FIGS. 24 ,  25 ,  26 ,  30  and  31 , the protruded curved surface  12   b  protruded toward the outside of the outlet  12  of the outlet path  14  is protruded from the center of the fixing member  220  of the syringe needle  200 , so that the medicament liquid is introduced into the inlet path  13  while being naturally dispersed to an outside due to the protruded curved surface  12   b  when the medicament liquid is sucked from an ampoule into the syringe body  100 . As shown in  FIGS. 26  and  31 , when the medicament liquid is injected into a patient through the inclined surface  11   c  after the medicament liquid is input while the inclined surface  11   c  is opened toward the outside of the inlet  11   a  of the opened inlet path  13   a , the medicament liquid is fully exhausted while being naturally dispersed to the outlet path  14 . 
     In this case, a guide groove  240   a  is formed from a step protrusion  240   a  by which a top surface of the inclined film  11   a - 1  is supported to a step protrusion  240  by which the front portion of the filter structure  10  is supported, so that the filter structure  10  is fixed without entering into an upper portion and the medicament liquid is easily introduced. 
     As shown in  FIG. 22 , the filter  20 , which is used to filter impurities when a medicament liquid is injected into a patient by exhausting the medicament liquid through the outlet  12 , may be formed in a plane  20   a  shape or in a hollow tube body  20   b  depicted  FIG. 28  which is not modified or torn due to the pressure generated in injection. A means may be used to allow the filter  20  to be latched at a predetermined position of the outlet path  14 , but may be variously modified in the scope of the objects of the present invention. 
     However, when the filter  20  is formed in the plane shape  20   a , a bottle neck phenomenon occurs so that the pressure is increased. To the contrary, when the filter  20  is formed in the tube body  20   b , the pressure is dispersed so that the injection is performed at a low pressure during the injection to a patient. 
     As shown in  FIGS. 22 and 28 , although the guide groove  230   b  is formed on the inner wall  230   a  of forming the inner space  230  of the fixing member  220  in order to form the closed inlet path based on the opened inlet path, even when a guide protrusion is substituted for the guide groove, the same effect is achieved. 
     The present invention is extensively applicable to fields of designing and manufacturing a medical optical treatment device to improve scalp and prevent hair loss. The present invention relates to a medical filter needle which is detachably installed to a syringe consisting of a cylinder and a piston in use in order to prevent a fine powder, which is generated from a glass or plastic ampoule, from being injected into a patient when the medicament liquid of the ampoule made of glass or plastic, which is absorbed into the cylinder of the syringe, is injected through a syringe needle, so that the safety of a patient is secured and the suction and injection are easily performed.