Medical needle assembly

Abstract

A medical needle assembly (10) which, in a released state, releases the restriction on movement of an inner needle member (14) by a restriction part (18). The elastic force of a biasing member (34) causes, while in said released state, the inner needle member (14) to move in a direction toward the base end, causing at least a needle tip (40) of an inner needle (30) to be stored inside a housing (36).

Description

medical needle assembly

[0001] The present disclosure relates to a medical needle assembly.

[0002] The medical needle assembly comprises an outer needle with an open tip, an outer needle hub connected to the base end of the outer needle, and an inner needle that is inserted into the lumen of the outer needle and can puncture a living body.

[0003] JP 2001-502191 A discloses a needle protection device capable of protecting a needle tip, such as the tip of an inner needle in a medical needle assembly. The needle protection device includes a needle guard slidably attached to the inner needle, a spring that biases the needle guard toward the tip of the inner needle, and a button that restricts movement of the needle guard toward the tip. When a user presses the button, the engagement between the button and the needle guard is released, and the needle guard moves toward the tip due to the elastic force of the spring. The needle guard covers the tip of the inner needle, preventing it from being exposed to the outside.

[0004] Special Publication No. 2001-502191

[0005] The needle protection device in JP 2001-502191 A is configured so that the user can activate the needle guard toward the distal end by pressing a button. Therefore, if the user forgets to press the button when removing the inner needle from the living body, for example, the needle guard will not move toward the distal end, leaving the tip of the inner needle exposed and potentially resulting in an accidental needle stick.

[0006] The present invention aims to solve the above-mentioned problems.

[0007] (1) An aspect of the present invention is a medical needle assembly comprising: an outer needle member having a tubular outer needle and an outer needle hub connected to the proximal end of the outer needle; an inner needle member having an inner needle inserted into the lumen of the outer needle and protruding in the distal direction from the tip of the outer needle, and an inner needle hub connected to the proximal end of the inner needle; a biasing member that elastically biases the inner needle member in the proximal direction; and a housing that accommodates at least the needle tip of the inner needle when the inner needle member is moved in the proximal direction by the elastic force of the biasing member; and a restricting portion that restricts movement of the inner needle member in the proximal direction by the elastic force in an initial state where the tip of the inner needle protrudes from the tip of the outer needle, a first housing connected to the proximal end of a needle hub and having at least a portion of the inner needle member inserted therein; and a second housing movable relative to the first housing in the axial direction of the housing and accommodating the inner needle hub and the biasing member, wherein in the initial state, the first housing is located at a first position relative to the second housing, and in a released state in which the first housing moves to a second position relative to the second housing as the first housing moves relative to the distal direction relative to the second housing, the restriction on movement of the inner needle member by the restricting part is released, and the inner needle member moves in the proximal direction due to the elastic force, with at least the needle tip being accommodated in the housing.

[0008] According to this configuration, when the user operates the operating unit to move the first housing from the first position to the second position, the restriction on the movement of the inner needle member toward the proximal end is released, and at least the needle tip of the inner needle is housed in the housing. Because at least the needle tip of the inner needle is housed in the housing in conjunction with the movement of the first housing, it is possible to prevent accidental punctures from occurring after the inner needle is removed from the outer needle hub.

[0009] (2) In the medical needle assembly described in (1) above, in the initial state, the regulating portion may maintain the restriction on movement of the inner needle member by pressing the inner needle member radially inward in a direction perpendicular to the axial direction, and in the released state, the regulating portion may release the restriction on movement of the inner needle member by reducing the pressing force on the inner needle member or by releasing the pressing force.

[0010] According to this configuration, the restriction on movement of the inner needle member can be simply and easily performed in the initial state, and the restriction on movement of the inner needle member can be simply and easily released in the released state.

[0011] (3) In the medical needle assembly described in (2) above, the regulating portion may have a pressing portion that, in the initial state, is located between the inner circumferential surface of the first housing and the outer circumferential surface of the second housing, thereby pressing the second housing radially inward, and a holding portion that is provided between the inner circumferential surface of the second housing and the inner needle member, and that, in the initial state, holds the inner needle member in the radial direction by the force of the pressing portion applied radially inward, and in the released state, the pressing portion is not located between the inner circumferential surface of the first housing and the outer circumferential surface of the second housing, thereby releasing the second housing from the state of being pressed by the pressing portion.

[0012] According to this configuration, the restriction on movement of the inner needle member can be more easily performed in the initial state, and the restriction on movement of the inner needle member can be more easily released in the released state.

[0013] (4) In the medical needle assembly described in (3) above, the pressing portion may be a protrusion formed on the distal end side of the inner circumferential surface of the first housing, and the holding portion may be an annular member disposed on the distal end side of the inner cavity of the second housing and through which the inner needle passes, and in the initial state, the protrusion presses the distal end side of the outer circumferential surface of the second housing radially inward, and the annular member is compressed radially inward by the pressing force of the protrusion, and in the released state, the protrusion may be positioned further distally than the second housing, thereby releasing the second housing from the pressing state.

[0014] According to this configuration, the movement of the inner needle member can be effectively restricted in the initial state, and the restriction on the movement of the inner needle member can be effectively released in the released state.

[0015] (5) In the medical needle assembly described in (4) above, the distal end of the second housing may be a protruding portion that protrudes in the distal direction, the protruding portion may have a plurality of elastic pieces that are spaced apart in the circumferential direction of the second housing and are flexible in the radial direction, and the annular member may be disposed inside the plurality of elastic pieces.

[0016] According to this configuration, in the initial state, the annular member can be easily compressed radially inward.

[0017] (6) In the medical needle assembly described in (4) or (5) above, the annular member may be an elastic member disposed in the inner cavity of the second housing.

[0018] According to this configuration, in the initial state, the elastic member is more easily compressed radially inward, thereby more effectively restricting movement of the inner needle member in the initial state.

[0019] (7) The medical needle assembly described in any one of (1) to (6) above may further include a tubular member capable of accommodating the housing, a fixing member fixed to the base end of the tubular member and fixing the base end of the second housing, and a stopper portion for preventing the first housing from slipping out of the tubular member in the distal direction.

[0020] According to this configuration, when the first housing moves relative to the second housing in the distal direction, the first housing can be prevented from coming off the tubular member.

[0021] (8) In the medical needle assembly described in (7) above, the stopper portion may have a first protrusion formed on the inner peripheral surface of the tubular member and a second protrusion formed on the outer peripheral surface of the first housing closer to the base end than the first protrusion, and in the released state, when the first housing moves relative to the second housing in the distal direction, the first protrusion and the second protrusion may abut in the axial direction.

[0022] According to this configuration, when the first housing moves relative to the second housing in the distal direction, the first housing can be effectively prevented from coming off the tubular member.

[0023] According to the present invention, when the user operates the operating unit to move the first housing from the first position to the second position, the restriction on the movement of the inner needle member in the proximal direction is released, and at least the needle tip of the inner needle is housed in the housing. Because at least the needle tip of the inner needle is housed in the housing in conjunction with the movement of the first housing, it is possible to prevent accidental punctures from occurring after the inner needle is removed from the outer needle hub.

[0024] Fig. 1 is a cross-sectional view of the medical needle assembly of this embodiment. Fig. 2 is a perspective view of the tip portion of the second housing. Fig. 3 is a cross-sectional view of the medical needle assembly. Fig. 4 is a cross-sectional view of a first modified example. Fig. 5 is a cross-sectional view of a second modified example.

[0025] 1 is a cross-sectional view of a medical needle assembly 10 according to this embodiment. The medical needle assembly 10 is a catheter assembly. When at least the tip of the medical needle assembly 10 is inserted into a living body such as a patient (not shown), a portion of the medical needle assembly 10 is retained within the living body.

[0026] The medical needle assembly 10 comprises an outer needle member 12, an inner needle member 14, a needle protection structure 16, a restricting portion 18, a tubular member 20, a fixing member 22, and a stopper portion 24. The outer needle member 12 has an outer needle 26 and an outer needle hub 28. The inner needle member 14 has an inner needle 30 and an inner needle hub 32. The needle protection structure 16 has a biasing member 34 and a housing 36.

[0027] The outer needle member 12 and the inner needle member 14 are connected along the central axis (axis 38) of the medical needle assembly 10. The outer needle member 12, the inner needle member 14, the housing 36, the biasing member 34, the tubular member 20, and the fixing member 22 are arranged coaxially with the axis 38. In the following description, the direction along the axis 38 will be referred to as the axial direction. The direction toward the outer needle member 12 along the axis 38 will be referred to as the distal direction. The direction away from the outer needle member 12 along the axis 38 (the direction toward the fixing member 22) will be referred to as the proximal direction. The direction perpendicular to the axis 38 will be referred to as the radial direction. The direction around the axis 38 will be referred to as the circumferential direction.

[0028] The outer needle member 12 is a catheter member. The outer needle 26 is a catheter. The outer needle 26 is a tubular member extending in the axial direction. The outer needle 26 is flexible. The outer needle 26 is made of a material such as a resin material. The tip of the outer needle 26 is open toward the tip. The tip of the outer needle 26 is the end that is inserted into a living body.

[0029] The outer needle hub 28 is a catheter hub. The outer needle hub 28 is a tubular member extending in the axial direction. The outer needle hub 28 is connected to the base end of the outer needle 26. The inner cavity of the outer needle 26 and the inner cavity of the outer needle hub 28 are in communication. The outer needle hub 28 is desirably made of a material that is harder than the outer needle 26. The outer needle hub 28 is made of a material that is harder than the outer needle 26, for example, a resin material.

[0030] The inner needle 30 is a tubular member having enough rigidity to puncture the skin of a living body. The inner needle 30 is inserted through the inner cavities of the outer needle 26 and the outer needle hub 28. The overall length of the inner needle 30 is sufficiently longer than that of the outer needle 26 and the outer needle hub 28. The tip of the inner needle 30 protrudes in the tip direction from the tip of the outer needle 26. The tip of the inner needle 30 is open in the tip direction. The base end of the inner needle 30 protrudes in the base direction from the connection portion of the outer needle hub 28 with the inner needle 30. The base end of the inner needle 30 communicates with the outside of the inner needle 30. The inner needle 30 is made of a metal material such as stainless steel, for example.

[0031] The inner needle hub 32 is a tubular member extending in the axial direction. The inner needle hub 32 fixes the proximal end side of the inner needle 30 in a state in which the inner needle 30 passes through the inner needle hub 32. The proximal end of the inner needle 30 protrudes in the proximal direction from the connection portion of the inner needle hub 32 with the inner needle 30. The inner needle hub 32 is made of, for example, a resin material.

[0032] The biasing member 34 elastically biases the inner needle member 14 in the proximal direction. The housing 36 accommodates at least the needle tip 40 of the inner needle 30 when the inner needle member 14 moves in the proximal direction due to the elastic force of the biasing member 34.

[0033] Specifically, the housing 36 has a first housing 42 and a second housing 44. The first housing 42 and the second housing 44 are each a cylindrical member extending in the axial direction. The first housing 42 and the second housing 44 are arranged coaxially along the axis 38. The length of the second housing 44 in the axial direction is longer than the length of the first housing 42 in the axial direction. The second housing 44 is arranged inside the first housing 42. The distal end of the second housing 44 is inserted into the inner cavity of the first housing 42. The proximal end of the second housing 44 protrudes in the proximal direction from the proximal end of the first housing 42. The first housing 42 and the second housing 44 are made of a material such as a resin material.

[0034] The first housing 42 has a first housing main body 46, a connection portion 48, and an operation portion 50. The first housing main body 46 is a cylindrical member extending along the axis 38.

[0035] The connecting portion 48 is a cylindrical portion that protrudes distally from the distal end surface of the first housing 42. The connecting portion 48 protrudes distally coaxially with the first housing main body 46. The inner cavities of the first housing main body 46 and the connecting portion 48 are in communication. The inner cavities of the first housing main body 46 and the connecting portion 48 constitute the inner cavities of the first housing 42. The outer diameter of the connecting portion 48 is smaller than the outer diameter of the first housing main body 46.

[0036] The connecting part 48 fits into the proximal end of the outer needle hub 28. More specifically, the connecting part 48 is inserted into the inner cavity of the outer needle hub 28 from the proximal end opening of the outer needle hub 28, thereby fitting the connecting part 48 and the outer needle hub 28. This brings the inner cavity of the first housing 42 and the inner cavity of the outer needle hub 28 into communication.

[0037] The operating unit 50 is provided on the outer peripheral surface of the first housing main body 46. The operating unit 50 protrudes radially outward from the tip side of the outer peripheral surface of the first housing 42. The operating unit 50 can be operated in the axial direction by a user.

[0038] The first housing body 46 has a first cylindrical portion 51 and a second cylindrical portion 53. The first cylindrical portion 51 is a cylindrical portion extending in the axial direction. The second cylindrical portion 53 is a cylindrical portion extending from the tip of the first cylindrical portion 51 toward the tip. The tip surface of the second cylindrical portion 53 is the tip surface of the first housing body 46. The connecting portion 48 extends from the tip of the second cylindrical portion 53 toward the tip. The operating portion 50 is provided on the outer peripheral surface of the second cylindrical portion 53. The outer peripheral surface 49 of the first cylindrical portion 51 and the outer peripheral surface of the second cylindrical portion 53 are flush with each other. The inner diameter of the second cylindrical portion 53 is smaller than the inner diameter of the first cylindrical portion 51. The inner diameter of the second cylindrical portion 53 is larger than the inner diameter of the connecting portion 48.

[0039] The second housing 44 has a second housing main body 54 and a protrusion 56 .

[0040] The second housing body 54 is a cylindrical member extending along the axis 38. The outer diameter of the second housing body 54 is smaller than the inner diameter of the first cylindrical portion 51 of the first housing body 46. The outer diameter of the second housing body 54 is larger than the inner diameter of the second cylindrical portion 53 of the first housing body 46. Therefore, the second housing body 54 is inserted into the inner cavity of the first cylindrical portion 51. The base end of the second housing body 54 protrudes in the base end direction from the base end of the first cylindrical portion 51.

[0041] The protrusion 56 is a cylindrical portion that protrudes distally from the distal end surface of the second housing 44. The protrusion 56 protrudes distally coaxially with the second housing main body 54. The inner cavities of the second housing main body 54 and the protrusion 56 are in communication with each other. The inner cavities of the second housing main body 54 and the protrusion 56 constitute the inner cavity of the second housing 44.

[0042] The outer diameter of the protrusion 56 is smaller than the outer diameter of the second housing main body 54. The outer diameter of the protrusion 56 is smaller than the inner diameter of the second cylindrical portion 53 of the first housing 42. The outer diameter of the protrusion 56 is larger than the inner diameter of the connecting portion 48 of the first housing 42. Therefore, when the second housing 44 is axially inserted into the first housing 42, the protrusion 56 can be inserted into the inner cavity of the second cylindrical portion 53.

[0043] The outer diameter of the inner needle 30 is smaller than the inner diameter of the protruding portion 56 of the second housing 44. The inner needle 30 is insertable into the inner cavities of the first housing 42 and the second housing 44 through the distal end opening of the first housing 42.

[0044] The inner needle hub 32 is disposed in the inner cavity of the second housing body 54. An annular flange 58 that protrudes radially outward is formed at the proximal end of the inner needle hub 32. The flange 58 is in sliding contact with the inner circumferential surface 47 of the second housing body 54. The biasing member 34 is disposed in the inner cavity of the second housing body 54. The distal end of the biasing member 34 is connected to the distal end portion of the second housing body 54. The proximal end of the biasing member 34 is connected to the flange 58 of the inner needle hub 32. The biasing member 34 has a resilient force that elastically biases the inner needle member 14 in the proximal direction via the flange 58. The biasing member 34 is, for example, a spring member.

[0045] The cylindrical member 20 extends along the axis 38. The housing 36 is inserted inside the cylindrical member 20. Therefore, the inner diameter of the cylindrical member 20 is larger than the outer diameter of the first housing main body 46. The distal ends of the first housing 42 and the second housing 44 protrude distally from the distal end of the cylindrical member 20. The operating unit 50 is located distally of the distal end of the cylindrical member 20.

[0046] The fixing member 22 fixes the base end of the second housing main body 54 of the second housing 44 to the base end of the tubular member 20. The fixing member 22 is a cap that closes the base end openings of the second housing main body 54 and the tubular member 20. The fixing member 22 is provided with an air vent filter 60. The air vent filter 60 allows air to pass between the inner cavity of the second housing 44 and the outside of the medical needle assembly 10, while preventing the passage of liquids such as blood.

[0047] 1, the state of the medical needle assembly 10 when the tip (needle point 40) of the inner needle 30 protrudes from the tip of the outer needle 26 is defined as the initial state. In the initial state, the axial position of the first housing 42 relative to the second housing 44 is defined as the first position.

[0048] In the initial state, the restricting portion 18 restricts the movement of the inner needle member 14 in the proximal direction due to the elastic force of the biasing member 34. In the initial state, the restricting portion 18 presses the inner needle member 14 radially inward, thereby maintaining the restriction on the movement of the inner needle member 14 in the proximal direction.

[0049] The restricting portion 18 has a pressing portion 62 and a holding portion 64 .

[0050] In the initial state, the pressing portion 62 is located between the inner circumferential surface of the first housing 42 and the outer circumferential surface of the second housing 44. The pressing portion 62 is a protrusion 66 formed on the tip side of the inner circumferential surface of the first housing 42. Specifically, the protrusion 66 is formed on the second tubular portion 53 of the first housing 42. The protrusion 66 is an annular protrusion that protrudes radially inward from the inner circumferential surface 52 of the second tubular portion 53. In the initial state, the protrusion 66 contacts the outer circumferential surface 57 of the protrusion 56 of the second housing 44.

[0051] The pressing portion 62 (protrusion 66) may be formed on the outer peripheral surface 57 of the protruding portion 56. In this case, the pressing portion 62 (protrusion 66) comes into contact with the inner peripheral surface 52 of the second cylindrical portion 53.

[0052] As shown in FIG. 2 , the protruding portion 56 has a plurality of elastic pieces 69. The plurality of elastic pieces 69 are spaced apart in the circumferential direction. Specifically, a plurality of slits 68 are formed in the protruding portion 56. Each of the plurality of slits 68 is formed in the axial direction. The plurality of slits 68 are formed in the protruding portion 56 at regular angular intervals in the circumferential direction. By providing the plurality of slits 68, a plurality of elastic pieces 69 are formed. Each of the plurality of elastic pieces 69 is flexible in the radial direction. FIG. 2 illustrates a case in which four slits 68 are formed at 90° intervals in the circumferential direction, thereby providing four elastic pieces 69 in the protruding portion 56.

[0053] 1 , the retaining portion 64 is provided between the inner circumferential surface of the second housing 44 and the inner needle member 14. Specifically, the retaining portion 64 is an annular member 70 arranged on the distal end side in the inner cavity of the protruding portion 56 of the second housing 44. Therefore, the annular member 70 is arranged inside the multiple elastic pieces 69. The inner needle 30 passes through the annular member 70.

[0054] The annular member 70 is preferably an elastic member 72. The elastic member 72 is made of rubber or a flexible resin. Two annular protrusions 73 are formed on the inner circumferential surface of the protruding portion 56 so as to sandwich the holding portion 64 in the axial direction. The two annular protrusions 73 restrict the movement of the holding portion 64 in the axial direction.

[0055] In the initial state, the protrusions 66 come into contact with the outer peripheral surface 57 of the protruding portion 56, causing the protrusions 66 to press the protruding portion 56 radially inward. A plurality of elastic pieces 69 (see FIG. 2 ) are formed on the protruding portion 56. The elastic pieces 69 receive a radially inward pressing force and can easily bend radially inward with the base end side of the protruding portion 56 as a fulcrum.

[0056] As the multiple elastic pieces 69 flex, the annular member 70 receives a radially inward pressing force and is compressed radially inward. As the annular member 70 is compressed, the inner needle 30 is held radially. As a result, the inner needle member 14 including the inner needle 30 is held radially.

[0057] In the initial state, the inner needle member 14 is held in the radial direction, and thus movement of the inner needle member 14 in the proximal direction is restricted against the elastic force of the biasing member 34 .

[0058] As shown in Fig. 3 , the position of the first housing 42 when the first housing 42 moves distally relative to the second housing 44 as a result of the user's operation of the operating unit 50 is defined as the second position. The second position is a position further distal than the first position shown in Fig. 1 . As shown in Fig. 3 , the state of the medical needle assembly 10 in the second position is defined as the released state. In the released state, the restriction on axial movement of the inner needle member 14 by the restricting portion 18 is released. That is, in the released state, the inner needle member 14 moves proximally due to the elastic force of the biasing member 34. As a result, at least the needle tip 40 of the inner needle 30 is housed in the housing 36.

[0059] Specifically, when the user operates the operating unit 50 relatively in the distal direction in the initial state shown in FIG. 1 , the first housing 42 moves relatively in the distal direction relative to the second housing 44. When the user further operates the operating unit 50 relatively in the distal direction, as shown in FIG. 3 , the pressing portion 62 (protrusion 66) is displaced distally beyond the second housing 44. As a result, the pressing portion 62 is no longer positioned between the inner circumferential surface of the first housing 42 and the outer circumferential surface of the second housing 44. As a result, the second housing 44 is released from the pressing state by the pressing portion 62 (protrusion 66). Released from the pressing state, the protrusion 56 (multiple elastic pieces 69) returns to its original position radially outward. The medical needle assembly 10 transitions from the initial state to the released state.

[0060] In the released state, the second housing 44 is released from its pressed state, and the retaining portion 64 (annular member 70) is released from its radially inward compressed state. This reduces the radially inward pressing force on the inner needle member 14, or releases the radially inward pressing force on the inner needle member 14. As a result, the restriction on the proximal movement of the inner needle member 14 is released.

[0061] When the movement restriction is released, the inner needle member 14 moves in the proximal direction due to the resilient force of the biasing member 34. As a result, at least the needle tip 40 of the inner needle 30 is housed in the housing 36. Figure 3 shows a state in which the entire inner needle member 14 is housed in the housing 36. In this case, the needle tip 40 of the inner needle 30 is housed in the lumen of the first housing 42.

[0062] In this way, in the initial state, the restricting portion 18 restricts the movement of the inner needle member 14 in the proximal direction, and in the released state, the restricting portion 18 releases the restriction on the movement of the inner needle member 14 in the proximal direction. To efficiently transmit the radially inward pressing force from the pressing portion 62 to the holding portion 64, it is desirable that the pressing portion 62 and the holding portion 64 be provided close to each other. For example, the pressing portion 62 and the holding portion 64 may be provided facing each other in the radial direction.

[0063] The stopper portion 24 prevents the first housing 42 from slipping out of the cylindrical member 20 in the distal direction. Specifically, the stopper portion 24 has a first protrusion 76 and a second protrusion 78. The first protrusion 76 is formed on the inner circumferential surface 21 of the cylindrical member 20. The first protrusion 76 is formed on the distal end side of the inner circumferential surface 21 of the cylindrical member 20. The second protrusion 78 is formed on the outer circumferential surface of the first housing 42 (the outer circumferential surface 49 of the first cylindrical portion 51) closer to the base end than the first protrusion 76.

[0064] When the user operates the operating unit 50 relatively in the distal direction and the first housing 42 moves in the distal direction relative to the second housing 44, the first protrusion 76 and the second protrusion 78 come into contact with each other in the axial direction. More specifically, the distal end side of the second protrusion 78 comes into contact with the proximal end side of the first protrusion 76 in the axial direction. This prevents the first housing 42 from coming off the tubular member 20.

[0065] Alternatively, the first protrusion 76 may be formed on the outer peripheral surface of the first housing 42, and the second protrusion 78 may be formed on the inner peripheral surface 21 of the tubular member 20. In this case, the first protrusion 76 is located closer to the base end than the second protrusion 78. As a result, when the first housing 42 moves relative to the second housing 44 in the distal direction, the distal side of the first protrusion 76 abuts against the proximal side of the second protrusion 78 in the axial direction. Even in this case, it is possible to prevent the first housing 42 from coming off the tubular member 20.

[0066] Next, the operation of placing the outer needle member 12 in a living body using the medical needle assembly 10 will be described.

[0067] 1, the user prepares the medical needle assembly 10 in an initial state, in which the first housing 42 is located in the first position.

[0068] Next, the user punctures the skin of the living body with the tip (needle point 40) of the inner needle 30 of the medical needle assembly 10. As a result, the tip of the inner needle 30 of the inner needle member 14 punctures a blood vessel of the living body, and the tip of the outer needle 26 is inserted into the blood vessel.

[0069] Next, the user moves the first housing 42 from the first position to the second position by relatively operating the operating unit 50 in the distal direction. As shown in Figure 3, when the first housing 42 moves to the second position, the pressing portion 62 (protrusion 66) of the first housing 42 is displaced further distally than the second housing 44. This releases the second housing 44 from the pressing state by the pressing portion 62, and the medical needle assembly 10 transitions from the initial state to the released state.

[0070] When the state shifts to the released state, the holding portion 64 (annular member 70) is released from its radially inward compressed state. This releases the restriction on the proximal movement of the inner needle member 14. With the movement restriction released, the inner needle member 14 moves proximally due to the resilient force of the biasing member 34. As a result, the entire inner needle member 14 is housed within the housing 36.

[0071] When transitioning from the initial state of FIG. 1 to the released state of FIG. 3, the second protrusion 78 abuts against the first protrusion 76, thereby preventing the first housing 42 from coming off the tubular member 20.

[0072] Next, the user pulls the tubular member 20 in the proximal direction while maintaining the position of the outer needle member 12. This causes the inner needle member 14 to be pulled out in the proximal direction from the outer needle member 12 and removed. As a result, removal of the inner needle member 14 from the outer needle member 12 is completed.

[0073] Thereafter, a syringe, a drug solution tube, etc. is connected to the outer needle hub 28 placed on the skin of the living body, and the drug solution is administered into the living body through the outer needle 26.

[0074] This embodiment has the following advantages.

[0075] 1 and 3 , when the first housing 42 is moved from the first position to the second position by the user operating the operating unit 50, the restriction on the movement of the inner needle member 14 in the proximal direction is released. As a result, at least the needle tip 40 of the inner needle 30 is housed in the housing 36. In this way, at least the needle tip 40 of the inner needle 30 is housed in the housing 36 in conjunction with the movement of the first housing 42. This makes it possible to prevent accidental punctures from occurring after the inner needle 30 has been removed from the outer needle hub 28.

[0076] In the initial state, the restriction on movement of the inner needle member 14 is maintained by pressing the inner needle member 14 radially inward. This makes it possible to simply and easily restrict movement of the inner needle member 14 in the initial state. Furthermore, in the released state, the restriction on movement of the inner needle member 14 is released by reducing the pressing force on the inner needle member 14 or by releasing the pressure. This makes it possible to simply and easily release the restriction on movement of the inner needle member 14 in the released state.

[0077] In the initial state, the pressing portion 62 is positioned between the inner circumferential surface of the first housing 42 (the inner circumferential surface 52 of the second tubular portion 53) and the outer circumferential surface of the second housing 44 (the outer circumferential surface 57 of the protrusion 56), thereby pressing the second housing 44 radially inward. The holding portion 64 holds the inner needle member 14 radially by the radially inward pressing force of the pressing portion 62. This makes it easier to restrict the movement of the inner needle member 14 in the initial state. Furthermore, in the released state, the pressing portion 62 is not positioned between the inner circumferential surface of the first housing 42 and the outer circumferential surface of the second housing 44, thereby releasing the second housing 44 from the state of being pressed by the pressing portion 62. This makes it easier to release the restriction on the movement of the inner needle member 14 in the released state.

[0078] In the initial state, the protrusion 66 presses the distal end side of the outer peripheral surface of the second housing 44 radially inward. The annular member 70 is compressed radially inward by the pressing force of the protrusion 66. This effectively restricts the movement of the inner needle member 14 in the initial state. Furthermore, in the released state, the protrusion 66 is positioned distally of the second housing 44, thereby releasing the second housing 44 from the pressing state. This effectively removes the restriction on the movement of the inner needle member 14 in the released state.

[0079] The protruding portion 56, which is the tip end of the second housing 44, is provided with a plurality of elastic pieces 69. The elastic pieces 69 are spaced apart in the circumferential direction and are flexible in the radial direction. The annular member 70 is disposed inside the elastic pieces 69. This allows the annular member 70 to be easily compressed radially inward in the initial state.

[0080] The annular member 70 is an elastic member 72 disposed in the lumen of the second housing 44. This allows the elastic member 72 to be more easily compressed radially inward in the initial state. As a result, in the initial state, movement of the inner needle member 14 can be more effectively restricted.

[0081] By using the stopper portion 24, it is possible to prevent the first housing 42 from coming off the tubular member 20 when the first housing 42 moves relative to the second housing 44 in the distal direction.

[0082] In the released state, when the first housing 42 moves distally relative to the second housing 44, the first protrusion 76 and the second protrusion 78 come into contact with each other in the axial direction. This effectively prevents the first housing 42 from coming off the tubular member 20.

[0083] A first and second modified example of this embodiment will be described with reference to Figures 4 and 5. Note that the same components as those in the medical needle assembly 10 of this embodiment (see Figures 1 to 3) are given the same reference numerals and detailed descriptions will be omitted. Figures 4 and 5 both show medical needle assemblies 100, 120 in their initial states.

[0084] As shown in Fig. 4 , in the medical needle assembly 100 of the first modified example, the inner needle 30 extends in the proximal direction more than the inner needle hub 32. As the inner needle 30 extends, the first housing body 46 and the second housing body 54 also extend in the proximal direction. The restricting portion 18 is located in the proximal direction more than the inner needle hub 32. That is, the retaining portion 64 is disposed on the proximal side of the lumen of the second housing body 54. Therefore, the proximal side of the inner needle 30 penetrates the retaining portion 64. The pressing portion 62 (protrusion 66) is formed on the outer peripheral surface 45 of the second housing body 54 so as to radially face the retaining portion 64. The protrusion 66 abuts against the inner peripheral surface 43 of the first tubular portion 51 of the first housing body 46.

[0085] In the initial state shown in Fig. 4, the first housing main body 46 presses the protrusion 66 radially inward. As a result, the annular member 70 is compressed radially inward and holds the inner needle 30. When the user operates the operation unit 50 to displace the first housing 42 from the first position to the second position, the protrusion 66 is displaced in the proximal direction relative to the first housing 42. The protrusion 66 is released from the pressing state by the first housing main body 46. This weakens the pressing force of the holding portion 64 against the inner needle 30. As a result, the inner needle member 14 moves in the proximal direction due to the elastic force of the biasing member 34 and is housed in the housing 36.

[0086] The first modified example also provides the same effects as the present embodiment (see FIGS. 1 to 3).

[0087] As shown in Fig. 5 , in a medical needle assembly 120 of the second modified example, the inner needle hub 32 extends in the proximal direction. As the inner needle hub 32 extends, the inner needle 30 also extends in the proximal direction. Specifically, the flange 58 of the inner needle hub 32 extends in the proximal direction. The restricting portion 18 is located more proximally than the biasing member 34. That is, the retaining portion 64 is a portion of the second housing body 54 that faces the flange 58 of the inner needle hub 32. The pressing portion 62 (protrusion 66) is formed on the outer peripheral surface 45 of the second housing body 54 so as to face the retaining portion 64 in the radial direction. The protrusion 66 abuts against the inner circumferential surface 43 of the first tubular portion 51 of the first housing body 46.

[0088] In the initial state shown in Fig. 5 , the first housing body 46 presses the protrusion 66 radially inward. Therefore, a part of the second housing body 54, which is the retaining portion 64, presses the flange 58 of the inner needle hub 32 radially inward. This restricts movement of the inner needle member 14 in the proximal direction. When the first housing 42 is displaced from the first position to the second position by the user operating the operating portion 50, the protrusion 66 is displaced in the proximal direction relative to the first housing 42. This weakens the pressing force of the retaining portion 64 against the flange 58. As a result, the inner needle member 14 moves in the proximal direction due to the elastic force of the biasing member 34 and is housed in the housing 36.

[0089] The effects of this embodiment can also be obtained in the second modified example.

[0090] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the present disclosure or the gist of the present disclosure derived from the content of the claims and their equivalents.

Claims

1. A medical needle assembly comprising: an outer needle member having a tubular outer needle and an outer needle hub connected to the proximal end of the outer needle; an inner needle member having an inner needle that is inserted into the lumen of the outer needle and protrudes distally from the tip of the outer needle, and an inner needle hub connected to the proximal end of the inner needle; a needle protection structure comprising: a biasing member that elastically biases the inner needle member in the proximal direction, and a housing that accommodates at least the needle tip of the inner needle when the inner needle member moves in the proximal direction due to the elastic force of the biasing member; and a restricting unit that restricts movement of the inner needle member in the proximal direction due to the elastic force in an initial state where the tip of the inner needle protrudes from the tip of the outer needle, wherein the housing has an operating unit operated by a user, and a first housing that is connected to the proximal end of the outer needle hub and has at least a part of the inner needle member inserted therein in the initial state; a second housing that is movable relative to the first housing in the axial direction of the housing and that accommodates the inner needle hub and the biasing member, wherein in the initial state, the first housing is located at a first position relative to the second housing, and in a released state in which the first housing moves to a second position relative to the second housing as the first housing moves relative to the distal direction relative to the second housing, the restriction on movement of the inner needle member by the restricting part is released, and the inner needle member moves in the proximal direction due to the elastic force, so that at least the needle tip is accommodated in the housing.

2. A medical needle assembly according to claim 1, wherein in the initial state, the restricting section maintains the restriction on movement of the inner needle member by pressing the inner needle member radially inward in a direction perpendicular to the axial direction, and in the released state, the restricting section releases the restriction on movement of the inner needle member by reducing the pressing force on the inner needle member or by releasing the pressure.

3. A medical needle assembly according to claim 2, wherein the regulating portion comprises: a pressing portion that, in the initial state, is located between the inner circumferential surface of the first housing and the outer circumferential surface of the second housing, thereby pressing the second housing radially inward; and a holding portion that is provided between the inner circumferential surface of the second housing and the inner needle member, and that, in the initial state, holds the inner needle member in the radial direction by the force of the pressing portion applied radially inwardly; and wherein, in the released state, the pressing portion is not located between the inner circumferential surface of the first housing and the outer circumferential surface of the second housing, thereby releasing the second housing from the state of being pressed by the pressing portion.

4. A medical needle assembly according to claim 3, wherein the pressing portion is a protrusion formed on the tip side of the inner peripheral surface of the first housing, and the holding portion is an annular member disposed on the tip side of the inner cavity of the second housing and through which the inner needle passes, and in the initial state, the protrusion presses the tip side of the outer peripheral surface of the second housing inward in the radial direction, and the annular member is compressed inward in the radial direction by the pressing force of the protrusion, and in the released state, the protrusion is positioned further in the tip direction than the second housing, thereby releasing the second housing from the pressing state.

5. A medical needle assembly according to claim 4, wherein the distal end of the second housing is a protruding portion that protrudes in the distal direction, the protruding portion has a plurality of elastic pieces that are spaced apart around the circumference of the second housing and are flexible in the radial direction, and the annular member is disposed inside the plurality of elastic pieces.

6. A medical needle assembly according to claim 4 or 5, wherein the annular member is an elastic member disposed in the inner cavity of the second housing.

7. A medical needle assembly according to any one of claims 1 to 5, further comprising: a tubular member capable of accommodating the housing; a fixing member fixed to the base end of the tubular member and fixing the base end of the second housing; and a stopper portion for preventing the first housing from slipping out of the tubular member in the direction of the tip.

8. A medical needle assembly as defined in claim 7, wherein the stopper portion has a first protrusion formed on the inner peripheral surface of the tubular member and a second protrusion formed on the outer peripheral surface of the first housing closer to the base end than the first protrusion, and in the released state, when the first housing moves relative to the second housing in the distal direction, the first protrusion and the second protrusion abut in the axial direction.

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