Patent Publication Number: US-2022233767-A1

Title: Puncture needle, puncture needle kit, and stereotactic brain surgery device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a puncture needle, and puncture needle kit, particularly for a living organism, and stereotactic brain surgery device. 
     BACKGROUND ART 
     One example of a puncture needle for infusing an object with fluidity such as liquid into a brain or spinal cord (central nervous system) is the needle device of Patent Literature 1. The needle device of Patent Literature 1 is used by being inserted in a brain from a front end part. A syringe in which liquid is stored is connected at a back end part of the needle device. A window part (discharge path) for infusion of liquid is formed at the front end part of the needle device, wherein the liquid is discharged from an aperture (discharge port) of the window part into the brain by manipulating the syringe. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Patent Literature 1: Japanese Patent No. 5665027 
     SUMMARY OF INVENTION 
     Solution to Problem 
     The present invention provides the following items. 
     (Item 1) 
     A puncture needle for infusing an object with fluidity into a brain, comprising: 
     a needle body along a forward/backward direction, wherein a passage for the object is formed inside; and 
     a discharge port of the object formed at an outer surface of a front end part of the needle body, 
     characterized in that:
         the needle body is a single tube comprising the passage; and   a surface area of a cross section of the discharge path orthogonal to a direction in which the discharge path extends is increased smoothly toward the discharge port in at least one part of the discharge path and, in each position regarding an extending direction of the discharge path, is equal to or greater than a surface area of the cross section in a position closer to the passage.       

     (Item 2) 
     The puncture needle of item 1, wherein the puncture needle consists of stainless, metal such as aluminum, ceramic, or inflexible rigid resin. 
     (Item 3) 
     The puncture needle of item 1 or 2, wherein the puncture needle comprises a connection part in which a syringe is connected to a back end of a needle body, wherein a distance between a tip of the connection part and a tip of a needle body part is about 170 mm to about 220 mm, wherein the needle body has an outer diameter that is about 1.6 mm or less. 
     (Item 4) 
     The puncture needle of any one of items 1 to 3, characterized in that an outer surface of the front end part comprises: a front end surface anteriorly projecting while smoothly bending; and a cylindrical side surface connected with the front end surface. 
     (Item 5) 
     The puncture needle of item 4, characterized in that a front end of the discharge port is positioned posterior to a front end of the passage and is positioned at a boundary between the front end surface and the side surface or positioned posterior to the boundary. 
     (Item 6) 
     The puncture needle of item 4 or 5, characterized in that the discharge port is formed behind the front end surface. 
     (Item 7) 
     The puncture needle of any one of items 1 to 6, characterized in that: 
     the front end part has a cylindrical side surface; and 
     at least one part of the discharge port is formed on the side surface. 
     (Item 8) 
     The puncture needle of any one of items 1 to 7, characterized in that an outer surface of the needle body is a surface contacting an organism upon puncturing, wherein a wall part from a passage of the needle body to an outer surface consists of a single layer. 
     (Item 9) 
     The puncture needle of any one of items 1 to 8, wherein the discharge path comprises a columnar part linked to the passage and a frustoconical part connecting the discharge port and the columnar part, 
     wherein an inner diameter of the passage is about 0.3 mm to about 1.2 mm, an inner diameter of the columnar part is about 0.3 mm to about 1.2 mm, and a frustoconical angle of the frustoconical part is about 90°. 
     (Item 10) 
     The puncture needle of item 9, wherein the discharge path further comprises a second columnar part between the discharge port and the frustoconical part, 
     wherein an inner diameter of the discharge port and a maximum inner diameter of the frustoconical part are about 1.2 mm to about 1.6 mm. 
     (Item 11) 
     The puncture needle of any one of items 1 to 7, wherein the discharge path comprises between the passage and the discharge port, from the passage side towards the discharge port, a frustoconical part or a columnar part with a first size and a frustoconical part or a columnar part with a second size that is greater than a first size, 
     wherein the first size is about 0.3 mm to about 1.2 mm and the second size is about 1.2 mm to about 1.66 mm. 
     (Item 12) 
     The puncture needle of items 1 to 7, wherein the discharge path comprises a frustoconical part linked to the passage and a columnar part provided between the discharge port and the frustoconical part, 
     wherein an inner diameter of the columnar part is about 0.3 mm to about 1.2 mm and a maximum inner diameter of the frustoconical part and the discharge port is about 1.2 mm to 1.6 mm. 
     (Item 13) 
     The puncture needle of any one of items 1 to 7, wherein the discharge path is provided with an angle α in the range that is over about 0° and about 30° in an inclined manner so that the discharge port side is positioned anterior to the passage side, 
     wherein an inner diameter on the passage side is about 0.3 mm to about 1.2 mm and a size of the discharge port is about 0.5 mm to about 1.2 mm. 
     (Item 14) 
     The puncture needle of any one of items 1 to 13, characterized in that, when water is flowed into the passage from a syringe, an infusion pressure of the water suppresses generation of a jet flow up to about 5 N. 
     (Item 15) 
     The puncture needle of any one of items 1 to 14, characterized in that the object comprises a cell. 
     (Item 16) 
     A puncture needle kit, characterized by comprising: 
     a container storing the object; and 
     the puncture needle of item 15. 
     (Item 17) 
     The puncture needle kit of item 16, further comprising an unravelling needle. 
     (Item 18) 
     A cell preparation, characterized by comprising: 
     a container storing the object; and 
     the puncture needle of item 15. 
     (Item 19) 
     A stereotactic brain surgery device, comprising: 
     the puncture needle of item 15; 
     a fixing frame fixed to a head part; 
     a head pin for fixing the fixing frame to the head part; 
     an arc-like frame that can be fixed to the fixing frame; and 
     a stopper that can be fixed to any position on the arc-like frame and defines an insertion length of the puncture needle. 
     (Item 20) 
     A method of administering a cell into a brain, the method comprising: 
     A) the step of providing a container for storing an object; 
     B) the step of disposing liquid comprising a cell in the container for storing the object; 
     C) the step of mounting the puncture needle of any one of items 1 to 14 on the container; 
     D) the step of filling the liquid comprising the cell to a tip so as to remove air inside as needed; 
     E) the step of advancing the puncture needle to a stopper in accordance with an angle of a stereotactic brain surgery device that was set beforehand while rotating a needle as needed; and 
     F) the step of administering the cell upon touching the stopper. 
     Furthermore, the present invention provides the following items. 
     (Item 1) 
     A puncture needle for infusing an object with fluidity into a central nervous system, comprising: 
     a needle body along a forward/backward direction, wherein a passage for the object is formed inside; 
     a discharge port of the object formed at an outer surface of a front end part of the needle body; and 
     a discharge path for the object extending from the passage to the discharge port, 
     characterized in that a surface area of a cross section of the discharge path orthogonal to a direction in which the discharge path extends is increased smoothly towards the discharge port in at least one part of the discharge path and, in each position regarding an extending direction of the discharge path, is equal to or greater than a surface area of the cross section in a position closer to the passage. 
     (Item 2) 
     The puncture needle of item 1, characterized in that an outer surface of the front end part comprises: a front end surface anteriorly projecting while smoothly bending; and a cylindrical side surface connected with the front end surface. 
     (Item 3) 
     The puncture needle of item 2, characterized in that a front end of the discharge port is positioned posterior to a front end of the passage and is positioned at a boundary between the front end surface and the side surface or positioned anterior to the boundary. 
     (Item 4) 
     The puncture needle of item 2 or 3, characterized in that the discharge port is formed behind the front end surface. 
     (Item 5) 
     The puncture needle of item 1 or 2, characterized in that: 
     the front end part has a cylindrical side surface; and 
     at least one part of the discharge port is formed on the side surface. 
     (Item 6) 
     The puncture needle of any one of items 1 to 5, characterized in that 
     an outer surface of the needle body is a surface contacting an organism upon puncturing, 
     wherein a wall part from a passage of the needle body to an outer surface consists of a single layer. 
     (Item 7) 
     The puncture needle of any one of items 1 to 6, characterized in that, when water is flowed into the passage from a syringe, a minimal value of a force applied to a syringe so that water discharged from the discharge port would form a jet flow is 2.6 N or greater. 
     (Item 8) 
     The puncture needle of any one of items 1 to 7, characterized in that, when water is flowed into the passage from a syringe while applying any size of force that is less than 5.7 N to a syringe, water discharged from the discharge port does not form a jet flow. 
     (Item 9) 
     The puncture needle of any one of items 1 to 8, characterized in that the object comprises a cell. 
     (Item 10) 
     A puncture needle kit, characterized by comprising: 
     a container storing the object; and 
     the puncture needle of item 9. 
     In the present disclosure, in addition to the explicitly shown combination, the above-mentioned one or more feature is intended to be provided in further combination. Those skilled in the art would further recognize another embodiment and advantage of the present disclosure when those skilled in the art read and understand the following detailed explanation as needed. 
     Advantageous Effects 
     The inventors of the present invention were the first ones to recognize that a conventional puncture needle (e.g., Patent Literature 1) has the fear of forming a jet flow of liquid or the like discharged from a discharge port in accordance with the syringe manipulation situation (see  FIG. 6  and  FIG. 7  of the present application) and has the risk of the formed jet flow causing injury to a central nervous system, and the inventors of the present invention found out that these risks would be reduced by the present disclosure. In addition, the inventors of the present invention were the first ones to recognize that the conventional puncture needle represented by Patent Literature 1 is a double pipe consisting of an outer needle and an inner needle, which causes the pore for insertion to a brain or central nervous system of a spinal cord to be large, the burden for opening a pore to the central nervous system to be great and the risk of causing injury to the central nervous system to be high, and the inventors of the present invention found out that these risks would be reduced by the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of the puncture needle of the first embodiment which is one exemplary embodiment of the present disclosure. 
         FIG. 2  is a partially enlarged view of  FIG. 1  including a partial cross section of the puncture needle. 
         FIG. 3( a )  is a partially enlarged view of  FIG. 2 .  FIG. 3( b )  is a plane view of  FIG. 3( a ) . 
         FIG. 4  is a schematic view of a stereotactic brain surgery device comprising the puncture needle of  FIG. 1 . 
         FIG. 5  is a diagram showing a state in which a stereotactic brain surgery device is mounted on the cranium of a patient. 
         FIG. 6  is a photograph showing an experimentation result using one Example of the puncture needle of  FIG. 1 . 
         FIG. 7  is a photograph showing an experimentation result using Conventional Example 1 with respect to the Example of  FIG. 6 . 
         FIG. 8  is a photograph showing an experimentation result using Conventional Example 2 with respect to the Example of  FIG. 6 . 
         FIG. 9  is a graph showing experimentation results including the results of  FIG. 6  to  FIG. 8 . 
         FIG. 10  is a graph showing experimentation results that are different from  FIG. 6  to  FIG. 9 . 
         FIG. 11  is a photograph showing further different experimentation results. 
         FIG. 12  is an outline diagram showing the configuration of the puncture needle kit of the second embodiment which is a different embodiment of the present disclosure. 
         FIG. 13  is a cross-sectional view of a front end part of the puncture needle of other modified examples. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The present disclosure is explained hereinafter. Throughout the entire specification, a singular expression should be understood as encompassing the concept thereof in the plural form, unless specifically noted otherwise. Thus, singular articles (e.g., “a”, “an”, “the”, and the like in the case of English) should also be understood as encompassing the concept thereof in the plural form, unless specifically noted otherwise. Further, the terms used herein should be understood as being used in the meaning that is commonly used in the art, unless specifically noted otherwise. Therefore, unless defined otherwise, all terminologies and scientific technical terms that are used herein have the same meaning as the general understanding of those skilled in the art to which the present disclosure pertains. In case of a contradiction, the present specification (including the definitions) takes precedence. The terms used in the present disclosure and the general technique are explained. 
     As used herein, “about” means ±10% of the numerical value that follows. 
     As used herein, “object with fluidity” refers to a matter with fluidity such as gas or liquid, or a configuration product or the like which is configured with a combination of matters with fluidity like a cell or the like, which is exemplified by a liquid agent, cell or the like. A matter that can be infused with an injector is normally within the scope of the object with fluidity. 
     The present disclosure generally provides a puncture needle, puncture needle kit and stereotactic brain surgery device, in which an object such as liquid discharged from a discharge port is less liable to form a jet flow, and less liable to cause injury to the central nervous system. In one example, the present disclosure provides a puncture needle for infusing an object with fluidity into a brain. This puncture needle comprises a needle body along a forward/backward direction, wherein a passage for the object is formed inside, and a discharge port of the object formed at an outer surface of a front end part of the needle body, wherein the needle body is a single tube comprising the passage, wherein a surface area of a cross section of the discharge path orthogonal to a direction in which the discharge path extends is increased smoothly towards the discharge port in at least one part of the discharge path and, in each position regarding the extending direction of the discharge path, is equal to or greater than a surface area of the cross section in a position closer to the passage. 
     In one non-limiting embodiment, according to the puncture needle of the present disclosure, the surface area of the cross section of the discharge path is increased smoothly towards the discharge port in at least one part of the discharge path. That is, at least one part of the discharge path is widened towards the discharge port. In addition, in each position regarding the extending direction of the discharge path, the surface area of the cross section of the discharge path is equal to or greater than a surface area of a cross section in a position closer to the passage. In other words, the surface area of the cross section of the discharge path does not change so as to be smaller towards the discharge port. This causes the object discharged from the discharge port to be less liable to form a jet flow (e.g., see  FIG. 6  of the present application). In addition, since the needle body is a single tube that comprises a passage for an object, the needle body can have a smaller outer diameter for the tube compared to a conventional double tube, thereby reducing the burden against the brain or central nervous system (see, for example,  FIG. 2  of the present application). The outer diameter of the needle tube may be any outer diameter. For example, the outer diameter of the needle body is about 2.0 mm or less, preferably about 1.6 mm or less, more preferably about 1.2 mm or less. Therefore, a puncture needle that is less liable to cause injury to the central nervous system is realized. 
     In another non-limiting embodiment, the inventors of the present invention thought that since a jet flow is formed in a conventional puncture needle because a discharge path is linearly formed (see FIG. 6 of Patent Literature 1), i.e., because the surface area of the cross section of the discharge path is constant. Although not wishing to be bound by any theory, the puncture needle of the present disclosure, which is for infusing an object with fluidity into a central nervous system, can unexpectedly suppress or lose a jet flow by the surface area of the discharge path orthogonal to the direction in which the discharge path extends increasing smoothly towards the discharge port in at least one part of the discharge path and, in each position regarding the extending direction of the discharge path, being equal to or greater than a surface area of a cross section in a position closer to the passage. In the puncture needle of the present disclosure comprising a needle body along a forward/backward direction, wherein a passage for an object is formed inside, a discharge port of the object formed at an outer surface of a front end part of the needle body and a discharge path of the object extending from the passage to the discharge port, this effect is also enhanced by the needle body being a single tube comprising a passage for an object. 
     In another non-limiting embodiment, it is preferable in the present disclosure that an outer surface of the front end part comprises a front end surface anteriorly projecting while smoothly bending and a cylindrical side surface connected to the front end surface. A conventional puncture needle has a sharply formed front end, or has a flatly formed front end as in Patent Literature 1. When such a puncture needle is inserted into an organism, the risk of the needle causing injury to a tissue such as a blood vessel would be high. In this regard, according to the above-mentioned configuration, the front end surface is curved, thereby reducing the fear of the needle causing injury to a tissue upon insertion into an organism. 
     In another non-limiting embodiment, it is preferable in the present disclosure that a front end of the discharge port is positioned posterior to a front end of the passage and positioned at a boundary between the front end surface and the side surface or positioned anterior to the boundary. There is a case of a cell or liquid being wasted by being accumulated in a portion anterior to a discharge port in a passage within a needle body. In this regard, according to the above-mentioned configuration, the front end of the discharge port is disposed at a boundary between the front end surface and the side surface or anterior to that. Therefore, in a passage, the portion from the front end thereof to the discharge path is liable to be relatively short. Thus, the amount of cell or liquid wasted by being accumulated in the portion from the front end to the discharge path of the passage would be relatively small. 
     In another non-limiting embodiment, it is preferable in the present disclosure that the discharge port is formed behind the front end surface. According to the above, the discharge port would be hidden behind the front end surface when seen from the anterior. Therefore, a tissue within an organism is less liable to intrude into the discharge port upon anteriorly inserting a puncture needle into the organism. 
     In another non-limiting embodiment, it is preferable in the present disclosure that the front end part has a cylindrical side surface and at least one part of the discharge port is formed at the side surface. According to the above, since at least one part of the discharge port is formed at the side surface, a tissue within an organism is less liable to intrude into the discharge port upon insertion of a puncture needle. 
     In another non-limiting embodiment, it is preferable in the present disclosure that an outer surface of the needle body is a surface contacting an organism upon puncturing and a wall part from a passage to the outer surface of the needle body consists of a single layer. According to the above, the inner diameter of the passage is liable to be formed as great as possible while suppressing the outer diameter of the needle body. The greater the inner diameter of a passage becomes, the less liable for a cell or the like to be clogged inside. Thus, it is effective that the inner diameter of the passage can be easily made as great as possible in the point that it is possible to prevent a cell or the like from being clogged inside the passage. 
     In another non-limiting embodiment, it is preferable in the present disclosure that, when water is flowed into the passage from the syringe, the minimum value of force applied to a syringe so that the water discharged from the discharge port will form a jet flow is about 1.5 N or greater, about 2.0 N or greater, about 2.3 N or greater, about 2.6 N or greater, or about 3.0 N or greater. According to the above, a puncture needle that is less liable to form a jet flow compared to a conventional puncture needle is realized. In this case, the maximum value of force applied to the syringe so that water discharged from the discharge port will form a jet flow may be about 6.0 N, about 5.7 N, about 5.4 N, about 5.0 N. 
     In another non-limiting embodiment, the object may comprise a cell in the present disclosure. When a call is comprised in an object, when a cell is clogged within a puncture needle, there is a fear of a user applying large pressure to the puncture needle in order to overcome the clogging. In view of the above, the fear of an object that flows out from a discharge port forming a jet flow would increase. Therefore, the technical significance of applying the technique provided in the present disclosure in such a case is great. 
     In another aspect, the present disclosure provides a method of administering a cell to a brain. This administration method comprises: A) the step of providing a container for storing an object; B) the step of disposing liquid (e.g., suitable liquid such as saline) comprising a cell (e.g., cells comprising a stem cell for brain infarction) in the container for storing the object; C) the step of mounting any puncture needle of the present disclosure on the container; D) the step of filling the liquid comprising the cell to a tip so as to remove air inside as needed (when air is removed, this step is not particularly necessary); E) the step of advancing the puncture needle to a stopper in accordance with an angle of a stereotactic brain surgery device that was set beforehand while rotating a needle as needed; and F) the step of administering the cell upon touching the stopper. Injury of a tissue inside the brain can be minimized by rotating the needle. 
     In this regard, a stereotactic brain surgery device may comprise: a fixing frame fixed to a head part; a head pin for fixing the fixing frame to the head part; an arc-like frame that can be fixed to the fixing frame; and a stopper that can be fixed to any position on the arc-like frame and defines an insertion length of the puncture needle. 
     When a needle is advanced to a stopper in accordance with an angle of a stereotactic brain surgery device such as a Leksell frame that was set beforehand, it will be confirmed that a guide stop is at a suitable position (e.g., may be 0 mm, may be −7 mm, or may be any other positions). Upon advancing a needle, the needle is advanced while rotating the needle so as not to cause injury to a brain blood vessel. That is, after wetting the tip, the needle is advanced while slowly rotating the needle for five minutes or longer. In this regard, the suitable position can be suitably changed depending on the position of the hole. For example, when a needle to be used has a hole from which a cell exits that is present at a place that is 7 mm from the tip of the needle, while a cell can be administered at a periphery of a target when punctured at ±0 mm, a brain tissue would be pierced 7 mm deeper than planned. Thus, it can be considered that a cell can fill the space where the needle has passed by pulling out the needle, and it is possible to achieve an actual site where the cell reaches even when the location where the cell exits still has 7 mm to reach the intended target. When a needle to be used is provided with a fan-shaped hole where a cell exists substantially near the tip, it is possible to employ, but not limited to, ±0 mm. 
     When a target location is reached and a stopper is touched, a cell is administered, and a syringe with a cell inside (e.g., 1 ml size) is attached to be slowly (e.g., for five minutes or longer) administered (as one example, a high dose is fifty million cells/1000 μl). The needle is pulled (e.g., about 3 mm) out to the front (in the case of −7 mm, it would be −10 mm) at the point when an appropriate amount (e.g., 200 μl) is in. This causes the cell to remain centering around a cavity where the needle was pierced. Herein, a small amount (e.g., 200 μl) can be administered again. A dead cavity of a needle (normally, but not limited to, about 20 μl) is within the scope of a margin of error. Then, the needle is left to stand at this location for an appropriate amount of time (e.g., five minutes), and then the needle can be pulled out. 
     Next, an appropriate hemostatic agent (e.g., gelfoam (medical gelfoam, sterile absorbable gelatin preparation which is a hemostatic agent; obtainable from Pfizer or the like), fibrin glue (Bolheal® that can be obtained from Teijin, periplast that can be obtained from CSL Behring) and the like) are placed at the surface of the hole, wherein flow-out of a cell can be prevented. This functions so that the pressure would not cause flowback of a cell that was deeply put in from the punctured hole upon pulling out the needle. In addition, the dura mater is filled with a hemostatic agent (e.g., gelfoam or the like). Herein, a tool such as a Burr hole cap is not used to decrease an infection risk. This causes the opened hole to be substituted with gelfoam, which would be replaced with a fibroblast in the future. 
     In another non-limiting embodiment, a puncture needle kit based on another viewpoint of the present disclosure comprises a container storing the object and the puncture needle. According to the above, the treatment of infusing an object taken out from a container into a central nervous system can be practiced using the puncture needle of the present disclosure. 
     Preferable specific embodiments of the present disclosure are explained below. The specific embodiments provided below are provided for better understanding of the present disclosure, wherein it is understood that the scope of the present disclosure should not be limited to the description below. Therefore, it is clear that those skilled in the art can appropriately make modifications within the scope of the present disclosure while considering the description herein. In addition, it is understood that the following embodiments of the present disclosure can be used alone or can be used in combination. 
     First Embodiment 
     A puncture needle  1  of the first embodiment which is one embodiment of the present disclosure is explained below while referring to  FIG. 1  to  FIG. 3 . The puncture needle  1  is used for transplanting a cell such as a stem cell to a specific position of a brain in surgery using a stereotactic brain surgery device for treating brain infarction. The puncture needle  1  comprises a needle body  10  linearly extending along one direction and a connection part  20  where a syringe to be fixed is connected to a back end part of the needle body as shown in  FIG. 1 . A cell to be administered into an organism is supplied from the syringe to the puncture needle  1 . Furthermore, the type and material quality of the connected syringe may be any type and material quality. Furthermore, it is preferable that the connection part  20  is configured so as to enable connection of a Hamilton syringe. According to the above, it is possible for a small amount of cells or liquid to precisely flow into the puncture needle  1 . 
     In addition, the stereotactic brain surgery device to which the puncture needle  1  is attached may be in any form. For example, may be a Komai-style stereotactic brain surgery device, or may be a Leksell frame. 
     Hereafter, the direction along the needle body  10  is referred to as the forward/backward direction as shown in  FIG. 1  to  FIG. 3 . Anterior is a direction in which the puncture needle  1  is inserted into an organism and posterior is a direction opposite thereto. In addition, the one direction orthogonal to the forward/backward direction is referred to as the upward/downward direction as shown in  FIG. 1 ,  FIG. 2  and  FIG. 3( a ) . A syringe insertion hole  21  where the tip of the syringe is inserted and a body insertion pore  22  where the needle body  10  is inserted are formed inside the connection part  20  as shown in  FIG. 2 . 
     The needle body  10  is a circular cylindrical member consisting of stainless, metal such as aluminum, ceramic, or inflexible rigid resin (with less flexibility). In the present disclosure, a circular shape does not strictly need to be a circle, but is enough if it is a medically allowed shape, which may be substantially circular (e.g., elliptical, or the like). It is possible to accurately insert a puncture needle to a desired therapy target point by making the material quality of the needle body  10  inflexible with metal, rigid resin, or the like. Preferably, a needle body is made of stainless that enables preparation such as sterilization processing at low cost. A passage  11  for a cell to pass through is formed inside the needle body  10  as shown in  FIG. 2  and  FIG. 3( a ) . The passage  11  is defined by an inner surface of a penetration port where the needle body is penetrated in the forward/backward direction and a surface of an occlusion part  12  made of metal wherein the aperture part of the front end of this penetration port is occluded. The passage  11  is opened towards the posterior in the back end of the needle body  10  and in communication with the syringe insertion hole  21  of the connection part  20 . A cell supplied from a syringe is infused into the passage  11  via the syringe insertion hole  21 . The cell infused into the passage  11  goes through the passage  11  by being pressured in from a syringe and towards a front end part  13  of the needle body  10 . The needle body  10  is not a conventional double tube but consists of a single tube in the present embodiment. That is, the puncture needle  1  is different from the needle of Patent Literature 1 having a double tube structure of an inner needle and an outer needle. Therefore, the outer diameter of the needle body  10  can be suppressed, and load to a patient or injury to the central nervous system can be reduced thereby. In addition, in the present embodiment, the needle body  10  consists of a single layer, wherein the wall part from the passage  11  to the outer surface is not divided in the middle. By carrying out the above, the inner diameter of the passage  11  can be formed as great as possible. In addition, the greater the inner diameter of the passage  11 , the less liable for a cell to be clogged inside. When a cell is clogged inside the passage  11 , there is a higher fear of injuring the inside of a brain by a cell and liquid discharged from a discharge port  15  forming a jet flow as discussed above. Therefore, as discussed above, the fact that the inner diameter of the passage  11  made of a single layer can easily be made as great as possible while suppressing the size of the outer diameter of the needle body made of a single tube is effective from the viewpoint of avoiding formation of a jet flow. 
     The inner diameter of the passage  11  may be any diameter. For example, the inner diameter is about 0.3 mm to about 1.2 mm, preferably about 0.5 mm to about 1.2 mm. 
     The length of the puncture needle may be any length. For example, the distance between a tip  20   a  of the connection part  20  and a tip  10   a  of the needle body  10  is about 150 mm to 230 mm, preferably about 170 mm to about 220 mm, more preferably about 170 mm to about 200 mm. 
     The front end part  13  of the needle body  10  has a front end surface  13   a  which is an outer surface anteriorly projecting and a side surface  13   b  which is a cylindrical outer surface as shown in  FIG. 3( a )  and  FIG. 3( b ) . The front end surface  13   a  has a smoothly bent hemispherical shape, and is smoothly connected with the side surface  13   b  at the back end. 
     A discharge port  15  that is circular when seen from above is formed in the front end part  13  as shown in  FIG. 3( b ) . A cell supplied from a syringe into the passage  11  is discharged from the discharge port  15 . The front end  15   a  of the discharge port  15  is positioned exactly at a boundary B between the front end surface  13   a  and the side surface  13   b . That is, the entirety of the discharge port  15  is formed within the range of the side surface  13   b  and the discharge port  15  would be disposed behind the front end surface  13   a . Therefore, the discharge port  15  will not be able to be seen as being hidden behind the front end surface  13   a  when the puncture needle  1  is seen from the anterior. 
     A discharge path  14  for a cell upwardly extending from the passage  11  to the discharge port  15  is formed inside the front end part  13 . The discharge path  14  consists of a substantially frustrum-like frustoconical part  14   a  and a substantially column-like columnar part  14   b . The lower end of the columnar part  14   b  is connected with the passage  11 . The connection position of the columnar part  14   b  and the passage  11  is a position that is posteriorly spaced apart from the front end of the passage  11 . The upper end of the columnar part  14   b  is connected with the lower end of the frustoconical part  14   a . The lower end of the frustoconical part  14   a  has the same shape as the upper end of the columnar part  14   b , i.e., a circular inner diameter with the same size as the inner diameter of the columnar part  14   b . The upper end of the frustoconical part  14   a  is connected with the discharge port  15  of a cell that is opened at the side surface  13   b  of the front end part  13 . 
     The discharge path  14  is formed so that the cross section thereof would have the following characteristics. Unless specifically noted otherwise, a cross section of the discharge path  14  is a cross section orthogonal to the direction in which the discharge path  14  extends, i.e., a cross section orthogonal to the upward/downward direction of  FIG. 3 . In addition, a cross section of the discharge path  14  is defined within the range surrounded by the dashed line E of  FIG. 3 . The dashed line E corresponds to the range excluding the range where the discharge port  15  is formed and the range where an aperture  14   c  of the discharge path  14  to the passage  11  is formed. The frustoconical part  14   a  is formed so that the surface area of the cross section would smoothly become greater from the lower end towards the upper end. In addition, the surface area of the cross section is constant regarding the columnar part  14   b . Thus, regarding the discharge path  14  consisting of the frustoconical part  14   a  and the columnar part  14   b , a surface area of a cross section in any position regarding the upward/downward direction is also equal to or greater than a surface area of a cross section of a position closer to the passage  11  than said position. For example, a cross section of any position regarding the upward/downward direction in the frustoconical part  14   a  also has a surface area greater than a cross section of any position that is more on the passage  11  side than said cross section. In addition, a cross section of any position regarding the upward/downward direction in the columnar part  14   b  also has a surface area equal to a cross section of any position that is more on the passage  11  side than said cross section. 
     The use method of the puncture needle  1  is explained while referring to  FIGS. 4 and 5 .  FIG. 4  is a schematic view of a stereotactic brain surgery device  200  comprising the puncture needle  1 , and  FIG. 5  is a diagram showing a state in which the stereotactic brain surgery device  200  is mounted on the cranium (head part) of a patient. A stereotactic brain surgery device  200  is set on the head part of a patient where a perforation has been formed at the cranium by trepanation as shown in  FIGS. 4 and 5 . The stereotactic brain surgery device  200  is a device for holding an insertion position and an insertion direction of a puncture needle  1  with respect to a brain at specific position and direction. The stereotactic brain surgery device  200  comprises a fixing frame  210 , a head pin  211 , an X-axis slide stand  220 , a Y-axis slide stand  230 , a Z-axis slide stand  240 , an arc-like arm  250  and a puncture needle  1 . The annular fixing frame  210  is made of metal and is mounted on the cranium of a patient. A plurality of head pins  211  are added to the fixing frame  210 . The head pin  211  is for fixing the fixing frame  210  to the cranium and is configured to be movable towards inside the annular fixing frame  210 . While the number of the head pints  211  may be any number, the number may be two, or may be three or more. In one embodiment, the number is four. The fixing frame  210  can be fixed to the cranium by mounting the fixing frame  210  on the cranium and moving the head pin  211  inside. In addition, the fixing frame  210  may comprise an X-axis slide stand  220  that is movable in a direction parallel to a surface of the fixing frame  210 , a Y-axis slide stand  230  and a Z-axis slide stand  240  that is movable in a direction orthogonal to a surface of the fixing frame  210 . An arc-like frame  250  is added to any of the X-axis to Z-axis slide stands  220 ,  230  and  240 . The arc-like frame  250  is removably fixed to any of the X-axis to Z-axis slide stands  220 ,  230  and  240  by a fastening means such as a bolt. In the embodiment showed in the drawings, the stereotactic brain surgery device comprises all of the X-axis to Z-axis slide stands, but the present invention is not limited thereto. It is possible to choose to select or not to select as needed. This arc-like frame  250  is in a shape that forms one part on a spherical body surface centering around a therapy target point where the puncture needle  1  reaches. Therefore, the distance to the therapy target point is constant from any position of the arc-like frame  250 . In addition, a puncture needle fixing part  260  that is movable on the arc-like frame  250  is added to the upper part of the arc-like frame  250 . Furthermore, the puncture needle  1  would be inserted into the puncture needle fixing part  260 . The puncture needle fixing part  260  comprises a base part that is movable on an arc-like frame  250  and an attachment part for attaching a puncture needle onto this base part. In addition, the puncture needle fixing part  260  is further provided with a stopper  261  for restraining the puncture needle  1  from entering deeper than a desired therapy target point (i.e., defining the insertion length of the puncture needle). The stopper  261  is configured to restrain insertion of the puncture needle  1  by engaging with the tip part  20   a  of the connection part  20  of the needle body  10 . The stopper  261  may be provided to the puncture needle  1  itself and not the puncture needle fixing part  260 . 
     Regarding the stereotactic  200  of the present disclosure, the puncture needle  1  is arbitrarily movable on the arc-like frame  250  and the arc-like frame  250  is movable in each direction by the X-axis slide stand  220 , the Y-axis slide stand  230  and the Z-axis slide stand  240 , thereby enabling the puncture needle  1  to reach a therapy target point from any point in the range covered by the fixing frame  210 . Therefore, it is possible to reach a therapy target point from the entire range of the cranial surface. 
     The puncture needle  1  is inserted into a brain from a brain surface through a perforation using the stereotactic brain surgery device  200  of the present disclosure. Upon the insertion, the front end part  13  is directed in the insertion direction and the puncture needle  1  is inserted by being slid along the forward/backward direction. Preferably, upon inserting a puncture needle inside a brain, the puncture needle is inserted while being slightly rotated. By carrying out the above, the needle can be inserted so as not to cause injury to a brain blood vessel. Upon the insertion, the front end part  13  advances deep into the brain while the outer surface of the puncture needle  1  comprising the front end surface  13   a  and the side surface  13   b  contacts a tissue inside the brain. This causes the front end part  13  to reach a target point inside the brain. Next, a syringe storing a cell together with liquid such as saline is connected via a connection part at a back end part of the puncture needle  1 . When an object stored in a syringe comprises cells, it is preferable that the cells be stored in the syringe after undergoing the operation of sufficient suspension to break a cell cluster. Next, the syringe is manipulated to pressure the inside cell and liquid into the puncture needle  1 . This causes the cell and liquid to be discharged from the discharge port  15  of the puncture needle  1  into the brain through the passage  11  and the discharge path  14  inside the puncture needle  1 . While a puncture needle was connected to a syringe after reaching a therapy target point in the explanation above, it is possible to have a puncture needle reach a therapy target point in a state in which the puncture needle is connected to a syringe. 
     According to the present embodiment explained above, the discharge path  14  of the puncture needle  1  has the following characteristics. First, in at least one part of the discharge path  14  (specifically, frustoconical part  14   a ), the surface area of the cross section thereof is increased smoothly towards the discharge port  15 . That is, at least one part of the discharge path  14  widened towards the discharge port  15 . Second, a surface area of a cross section of a discharge path  14  in any position regarding the direction in which the discharge path  14  extends is equal to or greater than a surface area of a cross section of a position closer to the passage  11  than said position. In other words, a surface area of a cross section of the discharge path  14  does not change so as to be smaller towards the discharge port  15 . Meanwhile, if a cross section of the discharge path  14  is constant regardless of the position, or if the discharge path  14  is formed so that a cross section would be smaller (a cross section would narrow down) towards the discharge port  15  in anywhere in the middle of the discharge path  14 , there is a fear of a cell and liquid discharged from the discharge port  15  forming a jet flow as shown in the Example discussed below. Specifically, in the case in which a cell is clogged inside the passage  11  or the like, there is a higher fear of forming a jet flow when there is a need for a greater pressure for pressuring in the cell in a syringe. Furthermore, when a cell and liquid discharged from a discharge port  15  form a jet flow, there is a higher fear of generating injury to the brain by the impact to the brain that is caused by the jet flow. In this regard, the discharge path  14  of the puncture needle  1  has the first and second characteristics as described above. Thus, as shown in the Example discussed below, the puncture needle  1  is less liable to form a jet flow. Therefore, a cell and liquid discharged from the discharge port  15  is less liable to cause injury to the brain. 
     In addition, in the present embodiment, the front end part  13  of the puncture needle  1  has a hemispherical front end surface  13   a . Meanwhile, when a front end of a needle is sharply formed or a front end surface is flatly formed, there is a higher risk of the needle causing injury to a tissue such as a blood vessel upon inserting the needle into a brain. In this regard, since the front end surface  13   a  is curved, there is a lower fear of a needle causing injury to a tissue upon insertion into a brain. 
     In addition, in the present embodiment, the discharge port  15  for a cell is disposed within the range of the side surface  13   b  of the front end part  13 . Therefore, the discharge port  15  will not be seen as being hidden behind the front end surface  13   a  when the needle body  10  is seen from the anterior. If the discharge port  15  is formed at the front end surface  13   a  and not the side surface  13   b , the discharge port  15  would be opened towards the anterior. Thus, the possibility of a tissue of a brain intruding the discharge port  15  upon inserting the puncture needle  1  into the brain would increase. In this regard, since the discharge port  15  is disclosed within the range of the side surface  13   b  and is hidden behind the front end surface  13   a  as described above, there is lower fear of a tissue intruding into the discharge port  15 . 
     In addition, in the present embodiment, the front end  15   a  of the discharge port  15  is positioned at a boundary B between the front end surface  13   a  and the side surface  13   b . If the front end  15   a  of the discharge port  15  is disposed posterior to this position, the portion from the front end to the discharge path  14  would be longer in the passage  11 . It is possible that a cell that reached this portion would remain in said portion without being discharged from the discharge port  15 . Therefore, there is a fear of the amount of wasted cells being greater when this portion is long. In this regard, since the front end  15   a  of the discharge port  15  is positioned at the boundary B between the front end surface  13   a  and the side surface  13   b  as described above, the length of the portion from the front end of the passage  11  to the discharge path  14  would be relatively smaller. Therefore, since it is possible make the length for inserting a puncture needle into a central nervous system as short as possible, it is possible to reduce burden to a patient and injury to the central nervous system. In addition, the amount of wasted cells is liable to be relatively small. From the viewpoint of making the length of the portion from the front end to the discharge path  14  of the passage  11  to be as small as possible, it is preferably that the back end of the occlusion part  12  be positioned as posteriorly as possible, i.e., as close as possible to the discharge path  14 . In addition, according to the above-mentioned viewpoint, it is most preferable that the back end of the occlusion part  12  be at the same position as the front end of the columnar part  14   b.    
     EXAMPLES 
     The First Example to the Third Example of the above-discussed embodiment are explained below. 
     First Example 
     In the First Example, a puncture needle  1  was configured in the following dimension. Outer diameter of a needle body  10 : about 1.5 mm. Inner diameter of a passage  11 : about 0.5 mm. Distance from a front end of a front end part  13  to a central axis of a discharge path  14 : about 1.4 mm. Distance between a tip of a connection part and a tip of the needle body: about 190 mm. Angle between one inclined surface and the other inclined surface of a frustoconical part  14   a  in  FIG. 3( a ) : about 90° (degree). Inner diameter of a columnar part  14   b : about 0.5 mm. Meanwhile, puncture needle S (Pittsburgh cell implantation cannula and stylette; Synergetics) and puncture needle M (biopsy/injection needle kit; Mizuho) were used as comparative examples. The puncture needle S has a front end part sharply formed and a discharge pot is formed at the front end and not at the side surface of the needle. The puncture needle M has a front end surface flatly formed and a discharge port is formed at a side surface of the needle that is 7 mm posteriorly away from the front end of the needle. In both puncture needles, the discharge path of a cell formed at the front end part is constant in terms of a surface area of a cross section orthogonal to a direction in which the discharge path extends regardless of a position regarding said direction. These puncture needles were used to carry out the following experimentation of flowing out water from the discharge port. Both puncture needles were disposed so that the height from the floor of an experimentation room to the discharge port would be the same with respect to one another and the aperture direction of the discharge port would substantially be in a horizontal direction. Furthermore, a syringe was connected to the back end of these puncture needles, and water was pressured into the puncture needle at a constant flow rate from the syringe so that the water would flow out from the discharge port of the front end part of each puncture needle. Furthermore, in the embodiment shown in  FIG. 3 , the angle between one inclined surface and the other inclined surface of the frustoconical part  14   a  is about 90°, but the present invention is not limited thereto. For example, the angle may be in the rage of about 45° to about 150°. In addition, the inner diameter of the columnar part  14   b  is about 0.5 mm and the inner diameter of the discharge port  15  is about 1.5 mm. However, the present invention is not limited thereto. The size may be any size that is equal to or less than the inner diameter of the columnar part  14   b . For example, the inner diameter of the columnar part  14   b  is about 0.3 mm to about 1.2 mm. In addition, the inner diameter of the discharge port  15  may be any size that is equal to or less than the diameter of the needle body  10 . For example, the inner diameter of the discharge port  15  is about 1.2 mm to about 1.6 mm. 
       FIG. 6  shows the result of experimentation using the puncture needle  1 ,  FIG. 7  shows the result of experimentation using the puncture needle S and  FIG. 8  shows the result of experimentation using the puncture needle M. All are results of when water is flowed into the puncture needle from a syringe at the flow rate of about 7 ml/minute. As shown in  FIG. 6 , water flowed out from the discharge port  15  of the puncture needle  1  so that the water would drop directly below the puncture needle. That is, the water flowing out from the discharge port  15  did not form a jet flow. Meanwhile, as shown in  FIG. 7  and  FIG. 8 , a jet flow was formed by the water discharged from the discharge port of the comparative examples.  FIG. 9  shows the result after repeatedly practicing the above-mentioned experimentation while changing the flow rate. The transverse axis of  FIG. 9  is flow rate. The longitudinal axis is the distance from the position of the discharge port of the puncture needle to the furthest position where the water reached. 
     Second Example 
     In the Second Example, the puncture needle  1  used in the First Example was connected to a syringe with the capacity of about 1 ml. The syringe stored water (specifically, ultrapure water). Next, water was pressured into the puncture needle  1  from a syringe so that the water would flow out from the discharge port  15  of the front end part  13  of the puncture needle  1  while using a digital force gauge (ZTA-50N; Imada) to measure the force applied to the plunger of a syringe. The above-described measurement was carried out while increasing little by little the force applied to the plunger of the syringe until the water discharged from the discharge port  15  forms a jet flow. This causes fifty discharges of the minimal size of force generating a jet flow (hereinafter, referred to as the minimal jet flow formation force) regarding the puncture needle  1 . As a result, as shown in  FIG. 10 , the average value of the minimal jet flow formation force of the puncture needle  1  was about 5.7 N. In addition, the same experimentation was carried out for each of the puncture needle S and puncture needle M in the First Example. As a result, as shown in  FIG. 10 , the average value of the minimal jet flow formation force of the puncture needle S was about 1.6 N. In addition, the average value of the minimal jet flow formation force of the puncture needle M was about 2.6 N. Furthermore, the above-described digital force gauge was used to measure the force that presses the plunger of the syringe in a state in which the puncture needle is not connected and, as a result, the force was about 1.0 N. 
     From the experimentation result above, it was found out that the puncture needle  1  of the present Example would not form a jet flow even when water is flowed in while applying any force within the range of about 5.7 N or less to the present syringe. In addition, according to the result of the puncture needle M with a large minimal jet flow formation force among conventional needles, it was found that the conventional minimal jet flow formation force is about 2.6 N. That is, it was found that a puncture needle that is less liable to form a jet flow compared to a conventional puncture needle is realized by configuring the puncture needle  1  of the present disclosure so that the minimal jet flow formation force would exceed about 2.6 N. 
     Third Example 
     In the Third Example, the puncture needle  1 , puncture needle S and puncture needle M that were used in the First Example were used. In addition, a false brain for infusing liquid using a puncture needle was made as described below. Fist, saturated borax aqueous solution was diluted 3 times with hot water. The diluted borax aqueous solution was blended with laundry starch that was multiplied by 15 by being mixed with water. A product in which saturated borax aqueous solution and laundry starch were blended in such a manner was heated and poured into a container so that air would not be mixed in to prepare three spherical false brains. Furthermore, upon preparing the false brains, the stiffness of the false brains was adjusted by adjusting the concentration of the borax aqueous solution after dilution. If the false brain is too hard, even when liquid is tried to be infused into the false brain using the puncture needle, there would be a problem of leakage from the gap between the needle and the false brain. In addition, if the false brain is too soft, there would be a problem of liquid infused into the false brain with the puncture needle rising to the upper part of the false brain by the difference in the specific gravity with respect to the false brain. The false brain would have suitable stiffness by diluting the saturated borax aqueous solution three times, wherein the above-described problems did not occur. 
     Each of the puncture needle  1 , puncture needle S and puncture needle M connected to a syringe is inserted into the three prepared false brains about 3 cm deep from the tip of the needle. Furthermore, Wright-Giemsa staining liquid that was diluted about three times from the stock solution is flowed into each puncture needle for about 30 seconds from a syringe at each flow rate of about 200, about 500, about 1000 and about 2000 μl/minute. As a result, as shown in  FIG. 11 , when the flow rate was about 2000 μl/minute, a projecting part, projecting downwards in the puncture needle S and sideways in the puncture needle M, was formed at the false brain. It is considered that this happened because liquid discharged from the discharge port of each puncture needle formed a jet flow and this jet flow caused great pressure to be applied to the false brain. Meanwhile, a projecting part was not formed in the puncture needle  1  even when the flow rate was about 2000 μl/minute and the false brain was shown to be substantially spherical. It is considered that this was because a jet flow was not formed like in the puncture needles S and M. 
     Second Embodiment 
     A second embodiment which is another embodiment of the present disclosure is explained below. The second embodiment is regarding the puncture needle kit  100  shown in  FIG. 12 . The puncture needle kit  100  comprises a puncture needle  1  of the first embodiment, a container  101  storing a cell and an unravelling needle  102  for unravelling cells. The container  101  stores a cell together with liquid such as saline and culture liquid. The container  101  may be provided with a device for maintaining the inside in a state suitable for delivery of a cell (temperature, position and the like). The unravelling needle  102  has an aperture that would be a circulation port for a cell at both ends and is a cylindrical member where a passage for a cell to be communicated between the apertures of both ends is formed inside. The aperture and passage of the unravelling needle  102  are adjusted to a size so that condensed cells would be unraveled into a state in which the cells are separated to a certain extent upon circulating the cells. For example, a cell within the container  101  is sucked up into a syringe through the unravelling needle  102  connected to the syringe. Alternatively, a cell once stored in a syringe is flowed out to the outside of the syringe through the unravelling needle  102  connected to the syringe. At least any of the above would unravel cells in a condensed state and be able to achieve a state in which the cells are separated to a certain extent. When said unraveled cells are transplanted into a brain using the puncture needle  1 , the cells are less liable to be clogged inside the puncture needle  1  compared to the case in which cells in a condensed state are used. Thus, there is lower fear of a cell and liquid discharged from the discharge port  15  of the puncture needle  1  forming a jet flow. 
     Modified Example 
     While the above is an explanation regarding a suitable embodiment of the present disclosure, the present disclosure is not limited to the above-discussed embodiment and can be changed in various ways only in the scope of matters described in the Solution to Problem. 
     For example, instead of the discharge path  14  of the above-discussed embodiment, any of the discharge paths  24 ,  34 ,  44  and  54  shown in  FIG. 13( a )  to  FIG. 13( d )  may be formed at the front end part of the needle body. The discharge path  24  is a passage for a cell linking the passage  11  and the discharge port  15  as shown in  FIG. 13( a ) . The inner surface of the discharge path  24  is bent in a curved-like manner in the cross section shown in  FIG. 13( a ) . The discharge path  24  is formed so that a surface area of a cross section orthogonal to the upward/downward direction (the direction in which the discharge path  24  extends) would increase in size in approximately two phases towards the discharge port  15  within the range surrounded by the dashed line E. The dashed line E shows the range that can define the cross section of the discharge path  24  in the same manner as the above-discussed embodiment. 
     By achieving the discharge path  24  of  FIG. 13( a ) , it becomes possible to accumulate cell liquid in a widened portion and then take the cell liquid outside, thereby enabling jet flow formation to be even weaker by this part being an interference site even when a jet flow is made therebelow. In the embodiment shown in  FIG. 13( a ) , a discharge path is an approximately columnar part with sizes in two phases, but the present invention is not limited thereto. For example, at least one may be an approximately columnar part, or may be an approximately frustoconical part. In addition, the phases may be three phases or more. 
     In  FIG. 13( a ) , for example, the inner diameter of the first approximately columnar part is about 0.3 mm to about 1.2 mm and the inner diameter of the second approximately columnar part is about 1.2 mm to about 1.6 mm. 
     As shown in  FIG. 13( b ) , the discharge path  34  is a passage for a cell linking the passage  11  and the discharge port  15 . Regarding the discharge path  34 , a surface area of a cross section orthogonal to the upward/downward direction in any position regarding the upward/downward direction (the direction in which the discharge path  34  extends) is also equal to or greater than a surface area of a cross section of a position closer to the passage  11  than said position within the rang surrounded by a dashed line E. The dashed line E shows a range that can define a cross section of the discharge path  34  in the same manner as the above-discussed embodiment. The discharge path  34  consists of a substantially column-like columnar part  34   a  and a substantially frustrum-like frustoconical part  34   b . The upper end of the columnar part  34   a  is connected with the discharge port  15  and the lower end of the columnar part  34   a  is connected with the upper end of the frustoconical part  34   b . The lower end of the frustoconical part  34   b  is connected with the passage  11 . The frustoconical part  34   b  is formed so that a surface area of a cross section orthogonal to the upward/downward direction would increase smoothly towards the discharge port  15  within the range surrounded by the dashed line E. By achieving the discharge path  34  of  FIG. 13( b ) , the discharge path  34  would have a widened portion at a tip where jet flow is prevented in a fan shape, thereby being able to doubly prevent a jet flow. For example, the smallest inner diameter of the frustoconical part is about 0.3 mm to about 1.2 mm and the maximum inner diameter of the frustoconical part and the inner diameter of the columnar part is about 1.2 mm to about 1.6 mm. 
     As shown in  FIG. 13( c ) , the discharge path  44  is a passage for a cell linking the passage  11  and the discharge port  15 . Regarding the discharge path  44 , a surface area of a cross section orthogonal to the upward/downward direction in any position regarding the upward/downward direction (the direction in which the discharge path  44  extends) is also equal to or greater than a surface area of a cross section of a position closer to the passage  11  than said position within the range surrounded by a dashed line E. The dashed line E shows the range that can define a cross section of the discharge path  44  in the same manner as the above-discussed embodiment. The discharge path  44  consists of a substantially column-like columnar parts  44   a  and  44   c  and a substantially frustrum-like frustoconical part  44   b . The upper end of the columnar part  44   a  is connected with the discharge port  15  and the lower end of the columnar part  44   a  is connected with the upper end of the frustoconical part  44   b . The lower end of the frustoconical part  44   b  is connected with the upper end of the columnar part  44   c . The frustoconical part  44   b  is formed so that a surface area of a cross section orthogonal to the upward/downward direction increases towards the discharge port  15 . The lower end of the columnar part  44   c  is connected with the passage  11 . By achieving the discharge path  44  of  FIG. 13( c ) , an aperture part can be made wider than the discharge path  34  of  FIG. 13( b )  and thus it is possible to further prevent the danger of a cell being clogged. For example, the minimum inner diameter of the frustoconical part and the inner diameter of the columnar part  44   c  are about 0.3 mm to about 1.2 mm and the maximum inner diameter of the frustoconical part and the inner diameter of the columnar part  44   a  are about 1.2 mm to about 1.6 mm. 
     As shown in  FIG. 13( d ) , the discharge port  54  is a passage for a cell extending from the passage  11  to the discharge port  15  along an α direction anteriorly inclined with respect to the upward/downward direction (dashed line). The inclination angle θ in the α direction with respect to the upward/downward direction (dashed line) may be any angle. For example, the angle is over about 0° and is about 30°, preferably about 10° to about 20°. The entirety of the discharge path  54  has a substantially conical shape. The discharge path  54  is formed so that a surface area of a cross section orthogonal to the α direction increases smoothly towards the discharge port  15 . Furthermore, a cross section of the discharge path  54  is defined within the range surrounded by the dashed line E′ of  FIG. 13( d ) . The dashed line E′ corresponds to a range excluding a range in which the discharge port  15  is formed and a range in which an aperture  54   c  of the discharge path  54  to the passage  11  is formed regarding the a direction. The minimum inner diameter of the discharge path  54  is about 0.3 mm to about 1.2 mm and the inner diameter of the discharge port is about 0.3 mm to about 1.2 mm. 
     By achieving the discharge path  54  shown in  FIG. 13( d ) , it is possible to prevent brain tissue from entering into the puncture needle  1  upon advancing the puncture needle  1  inside a brain. 
     In addition, regarding the puncture needle  1  of the above-discussed embodiment, the front end surface  13   a  of the front end part  13  has a hemispherical shape. However, the front end surface  13   a  may have any shape as long as the front end surface  13   a  is curved and anteriorly projecting. For example, the front end surface  13   a  may be along an ellipsoid or paraboloid. 
     In addition, in the above-discussed embodiment, the front end  15   a  of the discharge port  15  is positioned between a boundary B between the front end surface  13   a  and the side surface  13   b . However, the front end  15   a  of the discharge port  15  may be positioned posterior to the boundary B between the front end surface  13   a  and the side surface  13   b.    
     In addition, in the above-discussed embodiment, use of the puncture needle  1  for transplanting a cell such as a stem cell to a specific position of a brain is assumed in stereotactic brain surgery for treating brain infarction. However, the puncture needle  1  may be applied to other central nervous system, i.e., spinal cord. In addition, the puncture needle  1  may be used for the purpose of infusing an object with fluidity other than a cell such as liquid agent into a central nervous system. 
     Example 4: Cell Administration 
     An Example of cell administration is described below. If necessary, an animal used in the following Example is handled while observing the standard stipulated by Hokkaido University and based on the Declaration of Helsinki and GCP. 
     The following surgery is carried out using the needle prepared in each of the above-described embodiments. 
     (1) Insertion of Needle 
     In the present Example, a bone marrow stem cell is used as an object having fluidity. 
     After receiving a cell, suitable liquid (may be a culture medium for a cell, saline, or the like) is sufficiently suspended to break a cell cluster. An  18 G needle is used as a 1 ml injection needle for insulin and the needle of the present invention is used to suck cell suspension liquid into a syringe. Upon doing so, a needle to be transplanted is mounted from the posterior. Specifically, an inner cylinder is attached to an outer cylinder for injection and cell liquid is filled to the tip so as to remove the air inside. The needle is advanced to a stopper in accordance with the angle of Leksell frame that was set beforehand. In such a manner, it is confirmed that a guide stop is at a suitable position (e.g., may be 0 mm, or may be −7 mm). Upon advancing a needle, the needle is advanced while being rotated so as not to cause injury to a brain blood cell. That is, after wetting the tip, the needle is advanced while slowly being rotated for five minutes or longer. In this regard, the suitable position can be suitably changed depending on the position of the hole. For example, when a needle to be used has a hole from which a cell exits that is present at a place that is 7 mm from the tip of the needle, while a cell can be administered at a periphery of a target when punctured at ±0 mm, a brain tissue would be pierced 7 mm deeper than planned. Thus, it can be considered that a cell can fill the space where the needle has passed by pulling out the needle, and it is possible to achieve an actual site where the cell reaches even when the location where the cell exits still has 7 mm to reach the intended target. When a needle to be used is provided with a fan-shaped hole where a cell exists substantially near the tip, it is possible to employ ±0 mm. 
     (2) Cell Administration 
     When an intended location is reached (i.e., a cell is administered upon touching a stopper), a 1 ml syringe with a cell inside is attached and slowly administered for five minutes or longer (as one example, a high dose is fifty million cells/1000 μl). The needle is pulled about 3 mm out to the front (−10 mm) at the point when 200 μl is inside. This causes the cell to remain centering around a cavity where the needle was pierced. Herein, 200 μl is administered again. A dead cavity of a needle is about 20 μl, which is within the scope of a margin of error. Then, the needle is left to stand at this location for five minutes, and then the needle is pulled out. 
     (3) Closing Incision 
     Gelfoam (medical gelfoam, sterile absorbable gelatin preparation which is a hemostatic agent; obtainable from Pfizer or the like) and fibrin glue (Bolheal® that can be obtained from Teijin, periplast that can be obtained from CSL Behring) are placed at the surface of the hole, wherein flow-out of a cell is prevented (i.e., so that the pressure would not cause flowback of a cell that was deeply put in from the punctured hole upon pulling out the needle). In addition, a dura mater is filled with gelfoam (herein, a Burr hole cap is not used to decrease an infection risk). This causes the opened hole to be replaced with gelfoam (replaced with a fibroblast in the future). 
     (4) Result 
     As a result of the above, a cell is successfully infused into a brain. 
     Although the present disclosure has been exemplified using a preferable embodiment of the present invention as described above, it is understood that the scope of the present disclosure should be interpreted by the Claims alone. It is also understood that any patent, any patent application, and any references cited herein should be incorporated herein by reference in the same manner as the contents are specifically described herein. 
     INDUSTRIAL APPLICABILITY 
     The present disclosure is advantageous in being able to provide a puncture needle, a puncture needle kit and a stereotactic brain surgery device, wherein an object such as liquid discharged from a discharge port is less liable to form a jet flow and a central nervous system is less liable to be injured.
       1  Puncture needle     3   a  Front end surface     10 ,  10 ′ Needle body     11  Passage     13  Front end part     13   a ,  13 ′ a  Front end surface     13   b  Side surface     14 ,  14 ′,  24 ,  34 ,  44 ,  54  Discharge path     15 ,  15 ′ Discharge port     15   a  Front end