WO2023181799A1

WO2023181799A1 - Cannula of drug solution administration device and drug solution administration device including cannula

Info

Publication number: WO2023181799A1
Application number: PCT/JP2023/007221
Authority: WO
Inventors: 元紀水谷; 大輝加藤; 城司内山
Original assignee: テルモ株式会社
Priority date: 2022-03-22
Filing date: 2023-02-28
Publication date: 2023-09-28

Abstract

The present invention pertains to a cannula that is indwelt under the skin during administration of a drug solution, and that enables the drug solution to be administered in a stable manner.　The cannula (21) of a drug solution administration device comprises an outer wall surface (21b) facing the exterior and an inner wall surface (21a) forming a flow path for channeling the drug solution to the exterior, the outer wall surface of the tip section (21e) of the cannula being chamfered to prevent blockage of the flow path.

Description

Cannula of drug solution administration device and drug solution administration device including cannula

The present invention relates to a cannula for a liquid drug administration device and a liquid drug administration device including the cannula.

A treatment method that continuously administers a drug solution into a patient's body is known. For example, a method of continuously administering insulin into the body is known as a treatment method for diabetic patients. This treatment method uses a portable liquid drug administration device that can be carried and fixed to the user's body or clothing. If a portable drug solution administration device is used, it is possible to continuously administer a drug solution to a user. An insulin pump that administers insulin to a user is known as this type of drug administration device.

As one of the above-mentioned portable drug administration devices, a syringe pump type drug administration device has been proposed, which has a syringe (reservoir) in which a drug solution is stored, and a pusher (pump mechanism) that is driven inside the syringe. has been done. In a syringe pump type drug administration device, a cannula is fluid-tightly connected to a liquid delivery tube extending from a syringe, the cannula is punctured and placed under the user's skin, and a pusher is driven to store the liquid in the syringe. The device is designed to administer the medicinal solution into the user's body.

Patent Document 1 discloses a technique related to a liquid medicine administration device, which includes an elongated member including a side wall portion, a first end portion having a first open end, and a second open end, and a first end portion including a first open end. a fluid pathway extending through the elongate member between the end and the second open end, the first end portion being described as having an inner surface and an outer surface forming a fluid pathway. There is.

Japanese Patent Application Publication No. 2016-198411

A catheter (also referred to as a cannula) of a liquid drug administration device such as that disclosed in Patent Document 1 is required not only to have good subcutaneous penetration properties, but also to be able to stably administer a liquid drug from the cannula placed subcutaneously.

An object of the present invention is to provide a cannula for a drug solution administration device that can stably administer a drug solution from a cannula placed subcutaneously during drug administration, and a drug solution administration device including the cannula.

One aspect of the present invention is a cannula for a liquid drug administration device. The liquid drug administration device includes a delivery mechanism and a main body. The delivery mechanism includes a drug solution storage section that stores a drug solution to be administered to a living body, and a drive mechanism that generates a driving force to administer the drug solution stored in the drug solution storage section to the living body. The main body includes a mounting part to which a delivery mechanism can be mounted, and is configured to be attached to a living body. The cannula can be inserted into a living body, and is configured to be capable of administering a drug solution sent out from a drug solution storage section by a drive mechanism while being inserted into a living body. The cannula is attached to a holder that can be attached to the main body and includes a flow path through which a medical solution from a medical solution reservoir flows. The cannula includes an outer wall surface facing the outside and an inner wall surface forming a flow path through which the medical solution flows to the outside. The cannula has a chamfer formed on the outer wall surface of the distal end thereof to prevent the flow path from being blocked. One aspect of the present invention is a liquid drug administration device including the above cannula.

According to the cannula of the drug solution administration device according to one aspect of the present invention and the drug solution administration device including the above cannula, the drug solution can be stably administered from the cannula placed subcutaneously during drug solution administration.

FIG. 1 is a perspective view showing a puncture device related to a liquid drug administration device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the puncturing device according to FIG. 1; FIG. 3(A) is a plan view showing the mounting portion, FIG. 3(B) is a side view showing the mounting portion, and FIG. 3(C) is a rear view showing the mounting portion. FIG. 4(A) is a perspective view showing the second member forming the casing of the puncture device, and FIG. 4(B) is a perspective view showing the first member forming the casing. FIG. 5(A) is an enlarged view showing the first recess of the leg that constitutes the housing of the puncture device, and FIG. 5(B) is an enlarged view of the second recess of the leg. FIG. 6(A) is a perspective view showing the second member of the puncturing device, and FIG. 6(B) is a perspective view showing the second member from another direction. 7(A) is an enlarged view showing a portion 7A in FIG. 6(A), and FIG. 7(B) is an enlarged view showing a portion 7B in FIG. 6(B). FIG. 8(A) is a perspective view showing the first holding portion, and FIG. 8(B) is a sectional view taken along line 8B-8B shown in FIG. 8(A). FIG. 9(A) is a perspective view showing the second member of the casing housing the puncture needle holder in a state before the puncture needle protrudes, and FIG. 9(B) shows the puncture needle holder when the puncture needle protrudes. FIG. 9C is a perspective view showing the second member housing the puncture needle holder after the puncture needle has protruded. FIG. 7 is a diagram showing how the first holding part and the main body part engage with each other. FIGS. 11(A) and 11(B) are perspective views showing an example of operation of the puncturing device. FIG. 12(A) and FIG. 12(B) are perspective views showing an example of operation of the puncturing device. FIG. 3 is a perspective view showing how a delivery mechanism for delivering a drug solution is attached to the main body. FIG. 2 is a schematic plan view showing the structure of each part in a delivery mechanism that delivers a medical solution. FIG. 15(A) is a sectional view taken along the line 15-15 in FIG. 14, showing the state before the main body and the delivery mechanism are connected, and FIG. 15(B) is a sectional view showing the state before the main body and the delivery mechanism are connected. It is a figure showing a state. FIG. 3 is a cross-sectional view taken along the axial direction through the center of the tip of the cannula of the liquid drug administration device. 17 is an enlarged view showing part 17 of FIG. 16. FIG. 17 is a sectional view showing a cannula according to a modification of FIG. 16. FIG. FIG. 2 is an image showing the state of the tip of the cannula according to the first embodiment after being placed in the abdomen of a pig in Experiment 2. FIG. FIG. 2 is an image showing the state of the tip of the cannula according to the modified example of the first embodiment after being indwelled in the abdomen of a pig in Experiment 2. FIG. This is an image showing that the tip of the cannula was occluded in Experiment 2. 3 is a table showing the results of an experiment in which tip collapse was confirmed for each chamfer angle of the cannula of the first embodiment and the cannula of the modified example of the first embodiment in Experiment 1; This is a stained image of the puncture site in the pig's abdomen after the cannula according to the first embodiment was placed in the pig's abdomen in Experiment 3. It is an image of the puncture site in the pig's abdomen after the cannula according to the modified example of the first embodiment was placed in the pig's abdomen in Experiment 3.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown here are exemplified to embody the technical idea of the present invention, and are not intended to limit the present invention. In addition, all other possible embodiments, examples, operational techniques, etc. that can be considered by those skilled in the art without departing from the gist of the present invention are included within the scope and gist of the present invention, and are described in the claims. inventions and their equivalents.

Furthermore, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically by changing the scale, vertical/width dimensional ratio, shape, etc. from the actual thing as appropriate, but these are merely examples. However, this does not limit the interpretation of the present invention.

Additionally, in this specification, the direction from the puncture device 100 toward the skin is referred to as the lower surface direction, and the opposite direction is referred to as the upper surface direction.

In addition, in the following description, ordinal numbers such as "first" and "second" will be used, but unless otherwise specified, these are used for convenience and do not define any order.

FIG. 1 is a perspective view showing a puncturing device 100 according to the present embodiment. FIG. 2 is an exploded perspective view of the puncture device 100. 3(A) is a plan view of the mounting portion 18 seen from the top direction, FIG. 3(B) is a side view of the mounting portion 18 seen from the Y1 direction, and FIG. 3(C) is a plan view of the mounting portion 18 seen from the X1 direction. FIG. 4(A) is a perspective view showing the second member 35 of the housing 30, and FIG. 4(B) is a perspective view showing the first member 31 of the housing 30. 5(A) is an enlarged view showing the first recess 33a of the leg 33 constituting the housing 30, and FIG. 5(B) is an enlarged view showing the second recess 33b of the leg 33. 6(A) and 6(B) are perspective views showing the second member 35 of the housing 30. FIG. 7(A) is an enlarged view showing a portion 7A in FIG. 6(A), and FIG. 7(B) is an enlarged view showing a portion 7B in FIG. 6(B). FIG. 8(A) is a perspective view showing the first holding portion 130 (corresponding to the holding portion), and FIG. 8(B) is a sectional view taken along line 8B-8B in FIG. 8(A).

FIG. 9(A) is a perspective view showing the second member 35 of the casing 30 housing the puncture needle holder 111 in a state before the puncture needle 20 is projected, and FIG. 9(B) is a perspective view when the puncture needle 20 is projected. FIG. 9C is a perspective view showing the second member 35 housing the puncture needle holder 111 after the puncture needle 20 has protruded. . FIG. 10 is a diagram showing how the first holding section 130 and the main body section 10 engage with each other. 11(A), FIG. 11(B), FIG. 12(A), and FIG. 12(B) are perspective views showing operation examples of the puncturing device 100. FIG. 13 is a perspective view showing how the delivery mechanism 200 for delivering a medical solution is attached to the main body 10. As shown in FIG. FIG. 14 is a schematic plan view showing the structure of each part in the delivery mechanism 200. 15(A) is a sectional view taken along the line 15-15 in FIG. 14, showing a state before the main body 10 and the delivery mechanism 200 are connected, and FIG. 15(B) is a sectional view of the main body 10 and the delivery mechanism 200. 200 is a diagram showing a state in which the devices 200 are connected.

The puncturing device 100 according to the present embodiment can be used together with a predetermined delivery mechanism 200 for delivering a drug solution such as a drug solution (for example, insulin, etc.) (see FIG. 13). The puncture device 100 and the delivery mechanism 200 can constitute a drug solution administration device 1 that administers a drug solution into a living body.

As shown in FIGS. 1 to 3, the puncture device 100 generally includes a main body 10 that can be attached to the surface of a living body, a puncture needle 20 that includes a cannula 21 and an inner needle 22 inserted into the cannula 21, and a housing 30 that accommodates the needle 20; a puncture mechanism 110 that is provided within the housing 30 and performs a puncturing operation that introduces the puncture needle 20 into the living body as the housing 30 rotates relative to the main body 10; , a fixing mechanism 120 (see FIG. 10) that fixes the cannula 21 to the main body 10 in a state in which the puncture needle 20 protrudes from the bottom surface of the main body 10; The guide portion 300 guides the rotation of the housing 30 so that the housing 30 rotates in parallel.

As shown in FIG. 1, the puncture device 100 is provided with a safety cap 40 attached to a casing 30 connected to the main body 10. The main body portion 10 can be attached to a desired location in the living body where the cannula 21 is desired to be placed. When the safety cap 40 is removed, the housing 30 becomes rotatable relative to the main body 10 around the protruding direction Z of the puncture needle 20. In conjunction with the operation of rotating the housing 30 relative to the main body 10, the puncture needle 20 protrudes, the cannula 21 is fixed to the main body 10, and the connection between the main body 10 and the housing 30 is released. is performed continuously.

First, the overall configuration of the puncture device 100 will be described.

As shown in FIGS. 1 to 3, the main body 10 includes an attachment section 16 that can be attached to a living body, and an attachment section 18 that can be attached to a delivery mechanism 200 that delivers a predetermined medicinal solution into the living body via a cannula 21. It is configured as a cradle with . For example, known resin materials and metal materials can be used for the materials constituting each part of the main body (cradle) 10.

The attachment portion 16 of the main body portion 10 is provided on the bottom surface that is placed facing the surface layer of the skin of a living body when the device is used. The attachment portion 16 can be formed of double-sided tape, adhesive, or the like. Furthermore, the attachment portion 16 can be covered with release paper or the like before use.

As shown in FIG. 2, the mounting part 18 of the main body part 10 has a bottom part 11 on which a flat mounting surface 12 is formed, and a side wall part 13 rising from the bottom part 11. The delivery mechanism 200 can be placed on the placement surface 12 in a state after the housing 30 is removed from the main body 10 (see FIG. 13). The mounting surface 12 is formed with an insertion hole 12a (see FIG. 3(A)) through which the puncture needle 20 can be inserted.

The side wall portion 13 of the main body portion 10 includes a first side wall 13a extending in one direction along the outer periphery of the placement surface 12, as shown in FIGS. a second side wall 13b extending in another direction intersecting the first direction along the outer periphery of the mounting surface 12; and a third side wall 13b extending along the outer periphery of the mounting surface 12 opposite to the first side wall 13a. It has a side wall 13c. The side walls 13a, 13b, and 13c rise upward from the mounting surface 12.

A first holding part 130 that holds the cannula 21 is attached to the main body part 10. FIG. 16 is a cross-sectional view along the axial direction passing through the axial center of the cannula 21. FIG. 17 is an enlarged view showing part 17 of FIG. 16. The cannula 21 can be inserted into a living body, and is configured to be capable of administering a drug solution sent out from a drug solution storage section 221 by a drive mechanism 211, which will be described later, when the cannula 21 is inserted into the living body. The cannula 21 includes an inner wall surface 21a and an outer wall surface 21b, as shown in FIG. Furthermore, in this embodiment, a funnel-shaped portion 21p is provided on the proximal end side of the cannula 21 (see FIG. 15(A)).

The inner wall surface 21a is configured to form a flow path through which the chemical solution can flow. The inner wall surface 21a forms a cylindrical inner cavity in this embodiment. That is, the inner wall surface 21a has a substantially constant inner diameter. However, the specific shape of the inner wall surface 21a is not limited to the cylindrical side shape as long as the chemical solution can flow through the internal space. Note that in this specification, the axial direction corresponds to the longitudinal direction of the cannula 21, the distal direction of the cannula 21 is referred to as the P1 direction, and the proximal direction (i.e., the first holding part 130 side) is referred to as the P2 direction. The direction is parallel to the axial direction. The left direction in FIGS. 16 and 17 corresponds to the P2 direction, and the right direction corresponds to the P1 direction.

The outer wall surface 21b is configured such that at least a portion thereof faces the outside from the bottom surface of the main body 10 in the P1 direction when the first holding part 130 is attached to the main body 10. The outer wall surface 21b includes a base end portion 21c, a tapered portion 21d, and a distal end portion 21e (see FIG. 16).

The funnel-shaped portion 21p is provided further toward the proximal end of the cannula 21 than the proximal portion 21c. The cannula 21 is locked to the first holding part 130 at the funnel-shaped part 21p. The outer diameter and inner diameter of the cannula 21 gradually expand toward the proximal end of the proximal portion 21c to form a funnel-shaped portion 21p. In this embodiment, the proximal end portion 21c is configured to include a funnel-shaped portion 21p at the proximal end that matches the base portion 131 of the first holding portion 130, as shown in FIG. 15(A). However, regardless of this shape, as long as the cannula 21 is reliably fixed to the first holding part 130 and the medicinal solution sent from the medicinal solution storage part 221 can be delivered to the living body, the proximal end portion is not necessarily the funnel-shaped part 21p. It is not necessary to have

The outer diameter of the cannula 21 in the proximal portion 21c is configured to be constant. The proximal portion 21c, including the corresponding inner wall surface 21a, corresponds to the body of the cannula 21. In the proximal end portion 21c, the diameter of the lumen defined by the inner wall surface 21a is approximately constant.

The tapered portion 21d is formed on the outer wall surface 21b of the cannula 21 between the proximal portion 21c and the distal end portion 21e. The outer diameter of the tapered portion 21d decreases from the base end portion 21c to the distal end portion 21e (the outer wall surface 21b of the tapered portion 21d decreases radially inward toward the distal end portion 21e). That is, the thickness of the cannula 21 at the tapered portion 21d gradually decreases depending on the taper angle. Here, the angle between the straight line L1 extending the outer surface of the proximal portion 21c parallel to the axial direction toward the axial tip and the outer surface of the tapered portion 21d is defined as an angle θ2. The inclination of the tapered portion 21d can be configured such that the angle θ2 (see FIG. 16) is greater than 0.1 degrees and less than 4 degrees. Note that the angle θ2 may be within this range and may not be constant.

At least a portion of the distal end portion 21e corresponds to a portion of the liquid drug administration device that is placed under the user's skin. The tip portion 21e is provided with an opening for administering a medicinal solution to a user and communicating with a flow path formed by the inner wall surface 21a. As shown in FIG. 17, the distal end portion 21e is configured to have a chamfered portion with an inclined surface directed toward the axial center at the distal end. Here, in the tip portion 21e, the angle between the straight line L2 extending parallel to the axial direction from the base end of the chamfer toward the tip in the axial direction and the inclined surface of the chamfer is defined as the chamfer angle θ1. . The chamfering angle θ1 (see FIG. 16) can be configured to be more than 20 degrees and less than 90 degrees. The upper limit angle of the chamfer is preferably 60 degrees or less from the viewpoint of insertability of the cannula 21. That is, the angle θ1 is preferably greater than 20 degrees and less than 60 degrees. The distal end portion 21e is inclined so that the outer wall surface 21b gradually approaches the inner wall surface 21a at the end surface as it goes in the axial direction P1. In other words, in the distal end surface of the distal end portion 21e, the end surface of the inner wall surface 21a and the end surface of the outer wall surface 21b may be separated from each other, but preferably, they are linearly aligned without being separated from each other.

The material of the cannula 21 is not particularly limited, but examples include resin materials such as polyurethane, nylon, and ethylene-tetrafluoroethylene copolymer (ETFE). The dimensions of the cannula 21 are not particularly limited either, but the dimension d3 in the axial direction from the distal end 21e to the proximal end can be configured to a desired length in the range of 3 mm to 9 mm depending on the purpose (in the example described later). The cannula was made 6mm±1.2mm as d3). The diameter of the outer wall surface of the proximal end portion 21c is 0.7 mm ± 0.04 mm, and the wall thickness of the cannula 21 of the proximal end portion 21 c is 0.15 mm ± 0.07 mm (the tapered portion When 21d is not provided, the thickness of the proximal portion 21c is 0.13 mm, and when the angle θ1 is 40 degrees, and when the tapered portion 21d is provided, the thickness of the proximal portion 21c is 0.11 mm, and the angle θ1 is 55 degrees. In the case where the tapered portion 21d is not provided, the thickness of the proximal portion 21c is 0.12 mm), and the dimension d1 of the distal end portion 21e before the chamfer can be configured to be 0.5 mm to 0.7 mm. The inner cavity dimension d2 of the inner wall surface 21a can be configured to be 0.4 mm±0.1 mm. Further, the tip portion 21e may be provided with an end face perpendicular to the axial direction. The wall thickness of the cannula 21 before the chamfer can also be expressed as [(d1-d2)/2d1]×d1. The thickness of the tip end 21e of the cannula 21 before the chamfer is 0.13 mm when the angle θ1 is 40 degrees and the tapered portion 21d is not provided, and 0.07 mm when the angle θ1 is 40 degrees and the tapered portion 21d is provided. When the angle θ1 is 55 degrees and the tapered portion 21d is not provided, it can be 0.15 mm. Further, the length d6 in the axial direction from the boundary between the base end portion 21c and the tapered portion 21d to the boundary between the tapered portion 21d and the distal end portion 21e (also referred to as the taper length) can be 1.95 to 2.51 mm. Further, the axial length d7 from the boundary between the proximal end portion 21c and the tapered portion 21d to the distal end portion 21e (the sum of the length of the tapered portion and the distal end portion) can be 2.08 mm to 2.62 mm ( (See Figure 16).

The inner needle 22 is not particularly limited in its outer diameter, inner diameter, axial length, constituent material, etc., as long as it can form a puncture site at a site where a medicinal solution such as insulin is to be administered.

As shown in FIG. 2, FIG. 4(A), and FIG. 4(B), the housing 30 includes a first member 31 that accommodates the puncture mechanism 110, and a state in which the puncture needle 20 protrudes when the first member 31 is covered. The second member 35 is rotatably attached to the first member 31 with the direction Z as an axis.

As shown in FIG. 4(B), the first member 31 includes a substantially cylindrical tube 32 and extends from the outer circumferential surface of the tube 32, and when the first member 31 is connected to the main body 10. and a leg portion 33 that comes into contact with the mounting surface 12 of the mounting portion 18. The outer circumferential surface of the cylindrical body 32 forms a guide surface that guides the rotation of the second member 35 relative to the first member 31 about the protrusion direction Z of the puncture needle 20 as an axis.

As shown in FIGS. 5(A) and 5(B), the leg portion 33 has a first side wall 13a into which the first side wall 13a of the mounting portion 18 is inserted when the first member 31 is connected to the mounting portion 18. It includes a recess 33a and a second recess 33b into which the second side wall 13b of the mounting section 18 is inserted when the first member 31 is connected to the mounting section 18. By inserting the first side wall 13a into the first recess 33a, movement of the first member 31 is restricted in a direction intersecting the extending direction of the first side wall 13a. Further, by inserting the second side wall 13b into the second recess 33b, movement of the first member 31 is restricted in a direction intersecting the extending direction of the second side wall 13b. The leg portion 33 includes an opening portion 33c into which an engaging claw (not shown) of the safety cap 40 can be hooked (see FIG. 4(B)).

As shown in FIG. 4(A), the second member 35 includes a first cylinder 36 having a substantially cylindrical shape and a second cylinder 37 having an outer diameter larger than the outer diameter of the first cylinder 36. , the third cylindrical body 38 connecting the first cylindrical body 36 and the second cylindrical body 37, and the protruding direction Z of the puncture needle 20 with respect to the first cylindrical body 36 and the second cylindrical body 37 It has a knob portion 39 that applies a rotational force around the axis. By applying a rotational force to the knob portion 39, the user guides the inner circumferential surface of the first cylindrical body 36 of the second member 35 by the outer circumferential surface of the cylindrical body 32 of the first member 31, The second member 35 can be rotated relative to the first member 31.

<Puncture mechanism>
As shown in FIG. 2, the puncture mechanism 110 includes a puncture needle holding part 111 including a first holding part 130 that holds the cannula 21 and a second holding part 140 that holds the inner needle 22, and a puncture needle holding part 111 that holds the puncture needle 20 between the main body part 10 and the second holding part 140 that holds the inner needle 22. and a biasing member 112 that applies a biasing force in the protrusion direction Z to the puncture needle holder 111 to cause the puncture needle holder 111 to protrude from the puncture needle holder 111 .

The puncture needle holding section 111 has a first holding section 130 that holds the cannula 21 and a second holding section 140 that holds the inner needle 22. The puncture needle holder 111 is housed in the housing 30 in a movable state in the protruding direction Z of the puncture needle 20.

As shown in FIG. 8(B), the first holding part 130 includes a base part 131 that holds a part of the cannula 21 in a protruding state, and a liquid feeding pipe 222 that supplies a medicinal solution from the outside of the first holding part 130. It has a connection port 132 with a lumen into which a is inserted. The first holding part 130 also includes a cap 133 attached to cover the connection port 132, a lid member 134 attached to a side of the base 131 that is different from the side that holds the cannula 21, and a cap 133 that is attached to the base 131 to cover the cannula 21. 134, and a sealing member 135 provided between the two. The cap 133 and the seal member 135 are made of flexible members that have sealing properties. The base 131 includes an interior space 131a, and the connection port 132 includes a lumen 132a communicating with the interior space 131a. The internal space 131a and the lumen 132a constitute a flow path for a medicinal solution sent out from a medicinal solution storage section 221, which will be described later. A recess 136 that engages with a pair of arms 144 provided on the second holding part 140 is formed on the outer circumference of the base 131 . The lid member 134 forms a through hole 137 through which the inner needle 22 can be inserted (see FIGS. 8(A) and 8(B)).

The second holding part 140 has a base part 141 that holds the inner needle 22, as shown in FIG. The base portion 141 removes the inner needle 22 from the cannula 21 as the second holding portion 140 is pulled up from the main body portion 10 . A pair of arms 144 are formed on the base 141 and are provided with engagement claws that can engage with the recess 136.

The biasing member 112 applies a biasing force in the protrusion direction Z of the puncture needle 20 within the housing 30. As shown in FIG. 11(A), when the housing 30 is connected to the main body 10, movement of the housing 30 in the protruding direction Z of the puncture needle 20 and in the opposite direction is restricted. Therefore, the urging force applied by the urging member 112 restricts the housing 30 from moving in the protruding direction Z of the puncture needle 20 and the opposite direction. On the other hand, the puncture needle holder 111 is disposed so as to be movable in the protruding direction Z of the puncture needle 20 while housed in the housing 30 . Therefore, the puncture needle holding part 111 moves toward the protruding direction Z of the puncture needle 20 by the urging force applied from the urging member 112. As a result, the puncture needle 20 can pass through the insertion hole 12a formed in the placement surface 12 of the main body 10 and protrude from the main body 10.

Specifically, as shown in FIG. 9A, the top of the knob portion 39 of the second member 35 comes into contact with the second holding portion 140 of the puncture needle holding portion 111, and the second The movement of the holding part 140 is restricted. As shown in FIG. 9(B), when the second member 35 is rotated, the keyhole 39c formed in the knob portion 39 is aligned with the locking protrusion 143 of the second holding portion 140. When the positions of the locking protrusion 143 and the keyhole 39c overlap, the biasing force of the biasing member 112 is released, and the second holding part 140 moves in the protrusion direction Z, as shown in FIG. 9(C), and the inner needle 22 is projected toward the insertion hole 12a of the main body portion 10.

<Fixing mechanism>
As shown in FIG. 10, the fixing mechanism 120 is configured to move as the first holding section 130 moves relative to the main body section 10 in a direction different from the protruding direction Z (rotating motion of the second member 35). A fitting part 150 that engages the first holding part 130 with the main body part 10 is provided. The fitting part 150 includes a first fitting part 151 provided on the first holding part 130 side and a second fitting part 152 provided on the main body part 10 side and fitting into the first fitting part 151. Be prepared.

The first holding part 130 and the main body part 10 are arranged so that the first holding part 130 and the main body part When rotated relative to 10, they fit into each other via the respective fitting parts 151 and 152. The first holding part 130 is attached to the main body part 10 by the fixing mechanism 120.

<Guide section>
The guide section 300 is configured to support the housing 30 with respect to the main body 10 when the housing 30 rotates relative to the main body 10.

In this embodiment, the guide section 300 includes a first claw section 310 and a second claw section 320 formed on the second member 35, and a main body section 10, as shown in FIGS. 7(A) and 7(B). It has a first engaging part 360 and a second engaging part 370 formed in.

As shown in FIG. 4(A), the first claw portion 310 and the second claw portion 320 are formed on the second cylindrical body 37 of the second member 35.

The first engaging portion 360 is formed on the first side wall 13a of the side wall portion 13, as shown in FIG. 3(B). The second engaging portion 370 is formed on the second side wall 13b of the side wall portion 13, as shown in FIG. 3(C).

As shown in FIG. 7(A), the first engaging portion 360 is composed of a hole that can be engaged with the first claw portion 310. The second engaging portion 370 is constituted by a hole into which the second claw portion 320 can engage, as shown in FIG. 7(B).

The first claw portion 310 has a predetermined length along the rotational direction of the second member 35, as shown in FIG. 7(A). The first claw portion 310 separates from the first engagement portion 360 when the second member 35 rotates relative to the main body portion 10 while being engaged with the first engagement portion 360 .

The second claw portion 320 has a predetermined length along the rotational direction of the second member 35, as shown in FIG. 7(B). The second claw portion 320 separates from the second engagement portion 370 when the second member 35 rotates relative to the main body portion 10 while being engaged with the second engagement portion 370 . The second claw portion 320 is formed at a different position from the first claw portion 310 in the circumferential direction of the second member 35 .

As described above, the housing 30 and the main body part 10 are connected via the guide part 300 (each claw part 310, 320 and each engaging part 360, 370). The connection between the casing 30 and the main body 10 is such that the second member 35 of the casing 30 is It is released by further rotation relative to part 10. Thereby, the user can fix the first holding part 130 of the puncture mechanism 110 to the main body part 10 by a series of simple operations of rotating the second member 35 of the housing 30 relative to the main body part 10. and disconnection of the housing 30 and the main body 10 can be performed successively. Furthermore, while the safety cap 40 restricts the movement of the second holding part 140 by the locking protrusion 143 of the second holding part 140 and the keyhole 39c, the relative rotation of the second member 35 is restricted, and the guide part The respective claw portions 310 and 320 of 300 are in a state of being engaged with the respective engaging portions 360 and 370, and the connection between the main body portion 10 and the casing 30 can be prevented from being inadvertently disconnected.

<Example of operation of puncturing device>
Next, an operation example of the puncture device 100 according to this embodiment will be described with reference to FIGS. 11(A), 11(B), 12(A), and 12(B).

The user prepares the lancing device 100 and attaches the lancing device 100 to the body surface using the attachment section 16 provided on the main body section 10. As shown in FIG. 11(A), the user moves the second member 35 of the housing 30 in the direction of arrow r with each claw part 310, 320 engaged with each engaging part 360, 370. Rotate as shown. As shown in FIG. 11(B), the second member 35 of the housing 30 is guided (held) by the claws 310 and 320 when rotating. Therefore, it is possible to prevent the second member 35 of the housing 30 from rotating in an inclined state.

As shown in FIGS. 12(A) and 12(B), the user selects a position where the first claw part 310 comes out of the first engaging part 360 and a position where the second claw part 320 comes out of the second engaging part 370. Once the position is reached, the second member 35 of the housing 30 can be removed from the main body 10. Note that the puncturing of the puncturing needle 20 by the puncturing mechanism 110 occurs when the second member 35 of the housing 30 rotates to a predetermined position and the positions of the locking protrusion 143 and the keyhole 39c overlap (see FIG. 9(C)). ), the puncture needle 20 protrudes from the insertion hole 12a of the main body 10.

After placing the cannula 21 in the living body using the puncture device 100, the user removes the housing 30 from the main body 10. Next, the user attaches the delivery mechanism 200 to the main body 10, as shown in FIG.

As described above, after the casing 30 is removed from the main body 10, the first holding part 130 remains in the main body 10 with the cannula 21 introduced into the living body. The cannula 21 can be inserted approximately 5 mm from the patient's body surface. By connecting the delivery mechanism 200 for administering a predetermined medicinal solution to the first holding section 130, the user can send the medicinal solution into the living body via the connection port 132 of the first holding section 130.

The delivery mechanism 200 is not particularly limited as long as it is configured to be able to send a predetermined medical solution to the cannula 21, but for example, as shown in FIG. A liquid feeding reuse section 210 including a drive mechanism 211 etc. that generates the liquid feeding, a liquid feeding disposable section 220 that can be connected and separated from the liquid feeding reuse section 210, and a drug solution storage section 221 filled with a drug disposed in the liquid feeding disposable section 220. etc. can be used.

The liquid feeding reuse section 210 and the liquid feeding disposable section 220 are configured to be connectable and separable. After a predetermined period of use, when the chemical solution in the chemical solution storage section 221 is used up, the liquid feeding reuse section 210 and the liquid feeding disposable section 220 can be separated, and the liquid feeding disposable section 220 can be discarded and replaced with a new one. On the other hand, the liquid feeding reuse unit 210 is equipped with relatively expensive components that are replaced less frequently than the structural members installed in the liquid feeding disposable unit 220, such as a motor 211a and a gear train 211b, which will be described later. In this way, the component to be discarded after a predetermined period of use and the relatively expensive component are mounted in different housings, and the relatively expensive component is mounted in the liquid feeding reuse section 210 so that it can be reused. By doing so, we aim to reduce the cost of manufacturing the device and the cost associated with its use.

As shown in FIGS. 13 to 15, the liquid feeding reuse unit 210 includes a drive mechanism 211 that drives the members necessary to perform the liquid feeding operation, a control unit 212 that controls the drive mechanism 211, and a third unit that holds these. 1 housing 213. In addition, in FIG. 14, the part surrounded by the dotted line X represents the parts attached to the liquid feeding reuse part 210, and the part surrounded by the one-dot chain line Y represents the parts attached to the liquid feeding disposable part 220. Note that the first housing 213 is omitted in FIG. 14 for ease of understanding.

The drive mechanism 211 generates a driving force to administer the medicinal solution stored in the medicinal solution storage section 221 to the living body. The drive mechanism 211 includes a motor 211a having an output shaft that generates rotation using electric power from the battery 224 of the liquid supplying and disposable unit 220, and a motor 211a that decelerates the rotation generated by the motor 211a and transmitting the rotation to the extrusion mechanism 223 of the liquid supplying and disposable unit 220. It has a plurality of gear trains 211b for transmitting data.

As shown in FIG. 14, the liquid supply disposable part 220 communicates a liquid medicine storage part 221 filled with a liquid medicine to be administered with the inner cavity 132a of the connection port 132 of the first holding part 130 and the liquid medicine storage part 221. a pushing mechanism 223 that is mechanically connected to the drive mechanism 211 and pushes out the drug solution in the drug solution storage section 221 to the solution feed tube 222, and a battery 224 that supplies power to the drive mechanism 211 and the like. and a second housing 225 that holds the second housing 225.

The drug solution storage section 221 has a space for storing a drug solution to be administered to a living body. The liquid feeding tube 222 is, for example, a thin metal tube with a sharp tip. In this case, when the delivery mechanism 200 is coupled to the main body 10 while sliding the delivery mechanism 200 relative to the main body 10 as shown in FIG. 15(A), the arrangement shown in FIG. 15(B) is achieved. As shown, the sharp tip of the liquid feeding tube 222 passes through the cap 133 of the first holding part 130, and the liquid feeding tube 222 is inserted into the inner cavity 132a of the connection port 132. That is, while performing the work of connecting the delivery mechanism 200 to the main body part 10, the assembly work is performed to connect the liquid feeding pipe 222 and the connection port 132 so that the chemical solution can be sent to the first holding part 130. It can be carried out.

As shown in FIG. 14, the extrusion mechanism 223 includes a slide section 226 that is movable forward and backward in the internal space of the chemical solution storage section 221, and a feed screw that engages with a female screw formed in the slide section 226 to move the slide section 226 forward and backward. 227, and a gear 228 that meshes with the gear train 211b of the drive mechanism 211 and is connected to the feed screw 227.

As shown in FIG. 14, the slide portion 226 engages with a feed screw 227 and an extrusion member 226a that can move forward and backward within the drug storage portion 221 while maintaining sealing properties to prevent the drug from leaking toward the slide portion 226. It has a feed plate 226b formed with a female thread, and a pair of connecting plates 226c that connect the extrusion member 226a and the feed plate 226b.

After connecting the liquid feeding pipe 222 and the connection port 132, the feed screw 227 is rotated via the gear train 211b of the drive mechanism 211 and the gear 228 of the extrusion mechanism 223 by driving the motor 211a of the drive mechanism 211. . As the feed screw 227 rotates, the feed plate 226b moves along the helical axis of the male thread of the feed screw 227. The extrusion member 226a connected to the feed plate 226b via the connection plate 226c moves within the drug solution storage section 221 as the feed plate 226b moves. When the push-out member 226a moves in the direction in which it is pushed into the drug solution storage section 221 (the direction in which the volume of the accommodation space decreases), the drug solution in the accommodation space formed by the drug solution storage section 221 and the push-out member 226a is sent to the liquid supply pipe 222. liquid. The medicinal solution sent to the liquid sending tube 222 is introduced into the living body via the lumen 132a of the connection port 132, the internal space 131a of the base 131, and the cannula 21.

In this way, the puncture device 100 with the housing 30 removed and the predetermined delivery mechanism 200 can constitute a drug solution administration device that administers a drug solution into a living body.

As described above, the cannula 21 according to this embodiment is configured to be installed in the drug solution administration device 1. The liquid drug administration device 1 includes a delivery mechanism 200 and a main body portion 10 . The delivery mechanism 200 includes a drug solution storage section 221 that stores a drug solution to be administered to a living body, and a drive mechanism 211 that generates a driving force to administer the drug solution stored in the drug solution storage section 221 to the living body. The main body part 10 includes a mounting part 18 to which the delivery mechanism 200 can be mounted, and is configured to be able to be attached to a living body. The cannula 21 can be inserted into a living body, and is configured to be able to administer a drug solution sent out from a drug solution storage section 221 by a drive mechanism 211 while being inserted into the living body. The cannula 21 is attached to a first holding section 130 that can be attached to the main body 10 and includes a flow path through which a medical solution from a medical solution storage section 221 flows. The cannula 21 includes an outer wall surface 21b facing the outside and an inner wall surface 21a forming a flow path through which the medical solution flows to the outside. The cannula 21 has a chamfer formed on the outer wall surface of the distal end portion 21e. The chamfer formed on the distal end portion 21e is configured to prevent blockage of the channel for administering the medicinal solution, as will be described later. Thereby, the medicinal solution can be stably administered from the cannula 21 when administering the medicinal solution.

The present inventors focused on the fact that when a cannula used in a liquid drug administration device to administer a drug to a user is placed subcutaneously, the tip of the cannula can be crushed due to unintentional pressure on the drug liquid administration device. did. If the tip of the cannula collapses, an injection failure may occur. Specifically, as shown in the tip portion 21e indicated by the two-dot chain line in FIG. 17, when the tip portion of the cannula collapses inward in the radial direction, the lumen of the cannula, which corresponds to the flow path of the drug solution, is partially or completely closed. The inventors of the present invention have focused on the fact that the blockage is completely occluded, and that the blockage may lead to poor injection of the drug solution. When a drug solution administration device administers insulin as a drug solution, the tip of the cannula collapses, resulting in poor insulin injection, which may result in a hyperglycemic state in the user.

In contrast, in the cannula 21 according to the present embodiment, the angle θ1 of the chamfer formed on the outer wall surface 21b of the distal end portion 21e is greater than 20 degrees and less than 90 degrees with respect to the axial direction, preferably more than 20 degrees. It is configured so that the angle is 60 degrees or less. In other words, in an axial cross-sectional view, the thickness at the distal end of the cannula 21 decreases within a predetermined angular range toward the distal end of the cannula 21 . When placing the cannula 21 subcutaneously, the puncture resistance at the tip of the cannula 21 is suppressed, and while the cannula 21 of the liquid drug administration device 1 is placed subcutaneously, the tip 21e of the cannula 21 is pressed against the subcutaneous tissue. This prevents the container from collapsing and allowing continuous administration of the drug solution. Thereby, it is possible to prevent situations such as poor injection of the chemical solution from occurring.

Additionally, the cannula 21 includes a proximal portion 21c corresponding to a body portion and a tapered portion 21d. The base end portion 21c is provided on the base end side and has a constant radial dimension in the axial direction. The tapered portion 21d is provided closer to the distal end in the axial direction than the proximal portion 21c, and is formed so that the outer wall surface 21b decreases radially inward toward the distal end portion 21e. With this configuration, it is possible to prevent the distal end portion 21e of the cannula 21 from being crushed when the cannula 21 is placed subcutaneously, and to improve the insertability of the cannula 21.

Additionally, the tapered portion 21d is configured such that the angle θ2 with the axial direction is greater than 0.1 degrees and less than 4 degrees. With this configuration, when the cannula 21 is placed subcutaneously, the strength of the distal end side of the cannula 21 is ensured, the distal end portion 21e is prevented from being crushed, and furthermore, the insertability of the cannula 21 under the skin is improved. It can be made good.

(Modified example of the first embodiment)
FIG. 18 shows a cannula 21f according to a modification of the first embodiment, and is a diagram corresponding to FIG. 16. In the first embodiment, it has been described that the outer wall surface 21b of the cannula 21 includes the proximal portion 21c, the tapered portion 21d, and the distal end portion 21e. The outer wall surface 21g of the cannula 21f may include a proximal portion 21c and a distal end portion 21e, as shown in FIG. 18. In this case, the cannula 21f does not need to include the tapered portion 21d. By configuring the chamfer angle θ1 of the distal end portion 21e of the cannula 21f in the same manner as the cannula 21, it is possible to prevent situations such as poor injection of the medicinal solution and to enable stable administration of the medicinal solution. The other configurations of the cannula 21f and the liquid medicine administration device are the same as those in the first embodiment, so detailed explanations will be omitted.

The present inventors conducted Experiments 1 to 3 regarding the collapse of the tips of the cannulas 21 and 21f, which will be explained as follows.

(Experiment 1)
In Experiment 1, a load is applied to the cannula using an autograph, and it is confirmed whether the distal end portion 21e of the cannula has collapsed (In Vitro evaluation (indentation test)).

A cannula 21 including a proximal portion 21c, a tapered portion 21d, and a distal end portion 21e, and a cannula 21f without the tapered portion 21d were created. Cannulas 21 were evaluated in which the angle θ1 of the chamfer of the tip portion 21e was 20 degrees, 30 degrees, 40 degrees, and 55 degrees. The specifications of the tapered portion 21d of the cannula 21 were such that the chamfer angle θ1 was only 20 degrees and the taper angle θ2 was 4 degrees. The chamfer angles θ1 of the cannula 21 were 30 degrees, 40 degrees, and 55 degrees, and the nominal value of the angle θ2 was 1 degree, and the variations were made within 0.1 degrees to 4 degrees.

In addition, cannula 21f including a proximal end portion 21c and a distal end portion 21e but not having a tapered portion 21d were evaluated in which the chamfering angle θ2 of the distal end portion 21e was set to 30 degrees, 40 degrees, and 55 degrees.

Incidentally, the outer diameter dimension d1 at the position before the chamfering at the tip of the cannula 21 (sample No. 1) having a tapered portion 21d with a chamfering angle of 20 degrees was set to 0.5 mm. The cannula 21 has a tapered portion 21d, and the outer diameter dimension d1 at a position in front of the chamfer at the distal end of the cannula 21 when the chamfer angle θ1 is 30 degrees, 40 degrees, and 55 degrees is 0.6 mm. The outer diameter dimension d1 of the cannula 21f at the position before the chamfering when the chamfering angle θ1 without the tapered portion 21d is 30 degrees, 40 degrees, and 55 degrees is 0.71 mm. The inner diameter dimension d2 of the cannula was 0.4 mm in both specifications of the cannula 21 and 21f, and the dimension from the distal end 21e to the proximal end in the axial direction of the cannula 21 and 21f was 6.0 mm.

The specific method of evaluation will be explained. The cannulas 21 and 21f were axially clamped using an Autograph (AG-Xplus, manufactured by Shimadzu Corporation) and its dedicated jig. A load was applied in the axial direction from the distal end to the proximal end of the cannula 21, 21f at a pushing speed of 1 mm/min. At this time, an iron indentation measuring jig was used, the surfaces of which abut against the tips of the cannulae 21 and 21f were flat. When the load was continued to be applied to the tips of the cannulae 21 and 21f, the load was applied until the cannulae 21 and 21f completely kinked (bent). Thereafter, the edges of the tip openings of the bent cannulas 21 and 21f were evaluated to see if they were crushed or changed in shape.

The results of applying a load using an autograph to the above-mentioned four types of cannula 21 having the tapered part 21d and the above-mentioned three types of cannula 21f not having the tapered part 21d, and confirming the presence or absence of collapse at the tip part 21e are shown. Shown in 1. FIG. 22 is an image showing the tips of the seven types of cannula 21 or cannula 21f described above. The leftmost image in FIG. 22 is an image (sample No. 1) of a cannula tip opening with a chamfer angle θ1 of 20 degrees.

When we evaluated 10 of each of the 7 types of cannulas, we were able to confirm that none of them had their tips crushed or blocked. However, for the cannula 21 (sample No. 1) that is equipped with a tapered part 21d and has a chamfer angle θ1 of 20 degrees, although no tip collapse occurs, the deformation of the tip part 21e is the largest among the seven specifications. This was confirmed. From the opening at the tip of this cannula 21, it was possible for water to flow out in the form of a medicinal solution. Based on these results, the present inventors concluded that although a 20-degree chamfered tip does not pose a problem in normal use, it is possible to prevent a liquid drug administration device from colliding with a desk, etc. while worn on the body surface. If the sample is used in an unusual manner, such as when For cannula No. 1, it was determined that the possibility of occlusion occurring in the tip portion 21e that would make it difficult to withstand continuous administration could not be ruled out. Further, the present inventors determined that if the chamfer angle is more than 20 degrees and less than 55 degrees, it can withstand the above-mentioned use. Therefore, if the angle θ1 of the chamfer of the tip portion 21e is greater than 20 degrees and less than 55 degrees, it can be considered as a specification that can prevent the tip opening from collapsing. The angle of the chamfer can be formed up to 90 degrees, and it is thought that the larger the angle θ1 of the chamfer, the more advantageous it is to prevent tip collapse. Therefore, the upper limit of the angle θ1 is more than 55 degrees and less than 90 degrees. It can be considered that tip collapse can be prevented even if If the angle of the chamfer exceeds 90 degrees, it is considered undesirable because it becomes difficult to process the tip of the cannula and the insertion resistance when puncturing the cannula increases.

(Experiment 2)
In Experiment 2, the cannulas 21 and 21f described above were actually placed in the abdomen of a pig, and it was visually confirmed whether or not the tip portion 21e was crushed to cause blockage of the flow path. The reason for the evaluation by puncturing the pig's abdomen with a cannula is that the pig's abdomen is subject to more physical stress than that of humans. This is because it is possible to perform evaluations assuming extremely harsh conditions compared to when the liquid drug administration device is normally used by a person.

Cannulae having the same shape as Sample No. 3 and Sample No. 1 of Experiment 1 were created as the cannula 21 having the tapered portion 21d. In addition, a cannula having the same shape as Sample No. 7 of Experiment 1 was created as a cannula 21f without the tapered portion 21d. The cannulas 21 and 21f were made of ethylene-tetrafluoroethylene copolymer (ETFE) as a constituent material, and the outer diameter of the proximal portion was 0.7 mm. The cannula 21 of sample No. 3 including the tapered portion 21d had an outer diameter dimension d1 of 0.6 mm before the chamfer at the tip. On the other hand, the cannula 21f of sample No. 7 without a tapered portion has an outer diameter of 0.71 mm at the proximal end portion and the distal end portion, and a chamfer angle θ1 of 55 degrees. Regardless of the presence or absence of a tapered portion, the inner diameter dimension d2 of the cannula 21, 21f is 0.35 mm to 0.5 mm.

One cannula was punctured into the abdomen of six pigs and left in place for six days. After these catheters were removed from the pig's abdomen, the openings at their tips were visually checked to see if there was any collapse. When the tip opening was collapsed, in order to evaluate the degree of collapse of the tip opening, it was examined whether water, which was likened to a medical solution, naturally flowed out from the tip opening. Note that, as shown in the image shown in FIG. 21, if the tip was completely occluded to the extent that water, which was likened to a medicinal solution, could not naturally flow out from the tip, it was determined that the blockage had occurred due to tip collapse.

As a result of the observation, in the shapes of sample No. 3 and sample No. 7, the number of samples in which tip collapse was confirmed was zero. Sample No. The number of samples in which the tip opening was confirmed to be collapsed was 5 in the shape of No. 1. Three of these five tubes were so clogged that water, which was made to look like a chemical solution, could not naturally flow out from the opening at the tip. Sample No. in which collapse and occlusion of the tip opening were observed. A detailed observation of the cannula shaped as No. 1 revealed that in each case, the tip of the cannula was bent toward the inside of the tip opening. In particular, in the case of a cannula in which occlusion was found, the tip of the cannula that surrounds the tip opening is bent over the entire circumference of the tip opening, and is likely to be blocking the opening through which the drug solution passes. Understood. Furthermore, the axial length from the proximal end to the distal end of the cannula in which occlusion was observed was shorter than that of the cannula before implantation. Furthermore, it has been revealed that when the cannula has a predetermined wall thickness in its cross section, it can withstand bending inward at the tip opening. In the cannula of this embodiment, if the wall thickness in the cross section of the cannula was 0.06 mm, it could withstand bending toward the tip opening.

In this way, adjusting the chamfer angle of the tip to reduce the area where the tip of the cannula bends inward to the tip opening is considered to be effective in reducing occlusion. If the angle exceeds 55 degrees, the axial length of the region where the wall thickness of the cannula increases from 0 to 0.06 mm from the tip of the cannula where the wall thickness of the cannula converges to 0. It has been found that this is preferable because the length (dimension d5) can be shortened to 0 mm or more and less than 0.21 mm. Note that the dimension d5 preferably does not exceed the axial length (dimension d4) of the tip (see FIG. 17).

FIG. 19 is an image showing the tip of the cannula 21 of the first embodiment (sample No. 3) taken out after being placed in the abdomen of a pig. FIG. 20 is an image showing the tip of the cannula 21f (sample No. 7) according to a modified example of the first embodiment, which is taken out after being placed in the abdomen of a pig. FIG. 21 is an image showing an example of a cannula (sample No. 1) with a closed tip.

Figures 19 and 20 show sample No. 1 after placement in the pig's abdomen. 3. Sample No. Among the images of the tip portion 21e of No. 7, the tip portion showed relatively high deformation. Regardless of the specifications of the cannula 21 or 21f, it was confirmed that no collapse occurred in the opening of the tip end 21e in all samples. On the other hand, sample no. 1, it was suggested that the larger the angle of the tapered portion 21d and the smaller the chamfering angle of the tip, the more the thin area in the tip 21e, which makes the tip opening more likely to collapse.

(Experiment 3)
Next, Experiment 3 will be explained. There is concern that increasing the wall thickness at the tip of the cannula may affect inflammation that may occur in the subcutaneous tissue of the user where the cannula is placed. In Experiment 3, inflammation at the cannula placement site was confirmed.

In Experiment 3, after the cannula was removed in Experiment 2, a part of the skin tissue around the cannula placement site was removed and fixed with formalin. The fixed tissue was sliced and stained with hematoxylin and eosin (H.E.). This slice specimen was observed under a microscope, and the number of neutrophils, macrophages, etc. was comprehensively considered, and the degree of inflammation in the subcutaneous tissue was evaluated. In this evaluation, sample No. 1 and sample no. 7 was used. Sample No. No. 1 had the smallest outer diameter of the cannula among the samples, so it was selected as a cannula that was thought to have the least influence on the tissue. Sample No. No. 7 was selected because the outer diameter of the cannula was the largest. Both specifications are the same as in Experiment 1.

FIG. 23 shows sample No. FIG. 24 is an image showing the degree of inflammation at the puncture site after the cannula according to Sample No. 1 was placed in the abdomen of a pig. 7 is an image showing the degree of inflammation at the puncture site where the cannula 21f according to No. 7 was placed. In FIGS. 23 and 24, the insertion site of the cannula is shown surrounded by a black circle. Even in the case of the cannula 21f (sample No. 7) without the tapered portion 21d, the frequency of appearance of inflammatory cells such as neutrophils and macrophages at the cannula placement site is the same as that of sample No. 7. It was equivalent to 1. As a result, sample No. Cannula 21 according to Sample No. 1 and Sample No. 1 It was confirmed that with the cannula 21f according to No. 7, the degree of inflammation imparted to the subcutaneous tissue did not change. These results are similar to sample no. This is also considered to apply to cannula 21 having tapered portions 21d such as numbers 2, 3, and 4.

Note that the present invention is not limited to the above-described embodiments, and various changes can be made within the scope of the claims. In the above description, the drug solution administered by the drug solution administration device is insulin. However, the present invention is not limited to this, and the medicinal solution to be administered may be a medicinal solution other than insulin, as long as it is administered with the tip of the cannula punctured approximately 5 mm from the user's body surface.

This application is based on Japanese Patent Application No. 2022-045450 filed on March 22, 2022, the disclosure content of which is incorporated by reference in its entirety.

1 drug solution administration device,
10 main body,
18 attachment part,
21, 21f cannula,
21a inner wall surface (inner wall surface forming a flow path for the chemical solution),
21b, 21g outer wall surface,
21c proximal part,
21d Taper part,
21e tip,
130 first holding part (holding part),
200 delivery mechanism;
211 Drive mechanism,
221 Chemical solution storage section,
θ1 angle (chamfer angle),
θ2 angle (angle of tapered part).

Claims

a delivery mechanism that includes a drug solution storage section that stores a drug solution to be administered to a living body; and a drive mechanism that generates a driving force to administer the drug solution stored in the drug solution storage section to the living body;
The liquid medicine administration device is provided in a drug solution administration device having a main body portion which includes a mounting portion to which the delivery mechanism can be attached and which can be attached to a living body, and is insertable into the living body, and the drive mechanism is inserted into the living body. A cannula capable of administering the drug solution sent out from the drug solution storage section by
The cannula is attached to a holding part that is attachable to the main body and includes a flow path through which the medical solution from the medical solution storage part flows,
The cannula includes an outer wall surface facing the outside and an inner wall surface forming the flow path through which the medical solution flows to the outside,
The cannula is a cannula for a liquid drug administration device, in which a chamfer is formed on the outer wall surface of the distal end portion to prevent clogging of the flow path.
The cannula for a liquid medicine administration device according to claim 1, wherein the outer wall surface is formed at an angle of more than 20 degrees and less than 90 degrees with respect to the axial direction of the chamfer.
The outer wall surface includes a proximal portion provided on the proximal side and having a constant radial dimension in the axial direction, and a distal portion provided on the distal side in the axial direction from the proximal portion. 3. The cannula for a liquid drug administration device according to claim 2, further comprising a tapered portion in which the outer wall surface decreases radially inward as the outer wall surface approaches the portion.
4. The cannula for a liquid drug administration device according to claim 3, wherein the tapered portion is formed at an angle of 0.1 degrees to 4 degrees with respect to the axial direction.
A liquid drug administration device comprising the cannula according to any one of claims 1 to 4.