Drug administration device

Abstract

This drug administration device comprises: a cylindrical injection member that pierces the skin and injects a drug solution into a living body; and a guide member that has a through-hole into which the injection member is inserted and guides the injection member in a direction in which the injection member slides in the through-hole. The injection member has: a cylindrical sliding part including a flow path which is formed inside the cylindrical sliding part and through which the drug solution flows; and microneedles that are provided at an end part of the sliding part and communicate with the flow path. The guide member has: a guide member main body having the through-hole; an elastic body provided on the guide member main body on one end-side of the through-hole; and an adhesive layer provided on a surface of the elastic body. At least one of the injection member and the guide member has a first holding structure that holds the injection member in a first posture in which the tips of the microneedles are protruded from the adhesive layer.

Description

Medication equipment

[0001] This application claims priority from Japanese Patent Application No. 2024-151302, filed on September 3, 2024, the contents of which are incorporated herein by reference.

[0002] Conventionally, there are known devices for continuously administering a medicinal liquid into a living body, and such devices are configured to inject the medicinal liquid into the body by piercing the skin with a hollow puncture needle and then injecting the medicinal liquid into the body through the puncture needle.

[0003] The inventors have proposed a medication device having a fine needle called a "microneedle" as a minimally invasive medical device to replace the above configuration (see, for example, Patent Documents 1 and 2). A microneedle is a needle with a diameter and length of less than 1 mm (on the order of μm).

[0004] Japanese Patent No. 7023552 Japanese Patent Application Laid-Open No. 2022-110172

[0005] However, the configurations of Patent Documents 1 and 2 require the administration device to be used to pinch the skin of the subject and keep it fixed while administering the medication, which is uncomfortable to use and may cause the device to come off after prolonged use.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a novel medication device that employs microneedles and is capable of continuously administering a medicinal solution into a living body.

[0007] In order to solve the above problems, one aspect of the present invention includes the following aspects.

[0008] [1] A medication device comprising: a cylindrical injection part that punctures the skin to inject a medicinal solution into a living body; and a guide part that has a through hole into which the injection part is inserted and that guides the sliding direction of the injection part in the through hole, wherein the injection part has a cylindrical sliding part that has a flow path formed therein through which the medicinal solution flows, and a microneedle that is provided at an end of the sliding part and communicates with the flow path, and the guide part has a guide part main body that has the through hole, an elastic body that is provided on one end side of the through hole in the guide part main body, and an adhesive layer that is provided on the surface of the elastic body, and at least one of the injection part and the guide part has a first holding structure that holds the injection part in a first position in which the tip of the microneedle protrudes beyond the adhesive layer.

[0009] [2] The medication device described in [1], which has a second holding structure that holds the injection part in a second position in which the tip of the microneedle is housed within the through-hole.

[0010] [3] The medication device described in [2], wherein the second holding structure is an elastic member provided between the injection portion and the guide portion and holds the injection portion in the second position.

[0011] [4] A medication device according to any one of [1] to [3], wherein the elastic body surrounds the periphery of the through hole.

[0012] [5] The medication device according to [4], wherein the elastic body has a closed ring shape when viewed in a plane.

[0013] [6] A medication device according to [4] or [5], wherein the elastic body is thicker on the outer periphery than on the inner periphery.

[0014] [7] A medication device described in any one of [1] to [6], wherein the guide body has a recess on the one end side into which the elastic body fits.

[0015] [8] A medication device according to any one of [1] to [7], wherein the elastic body is replaceable.

[0016] [9] The medication device according to [8], which has a second elastic body having a different elastic modulus from the elastic body as a part replaceable with the elastic body.

[0017]

[10] The medication device described in any one of [1] to [9], wherein the sliding part has a cylindrical sliding part main body in which a part of the flow path is formed, and a flow path member that communicates with a part of the flow path of the sliding part main body and is connectable to an external device that injects the medicinal solution into the medication device, and the flow path member is detachable from the sliding part main body.

[0018]

[11] The medication device according to

[10] , which has a second flow path member connectable to a second external device as a part replaceable with the flow path member.

[0019] According to the present invention, a novel medication device can be provided that employs microneedles and is capable of continuously administering a medicinal solution into a living body.

[0020] Fig. 1 is a schematic perspective view showing a medication device 1 of an embodiment. Fig. 2 is an exploded perspective view of the medication device 1. Fig. 3 is a schematic perspective view of a sliding part 11 (sliding part main body 12) of the medication device 1. Fig. 4 is an explanatory diagram illustrating the operation of the medication device 1. Fig. 5 is an explanatory diagram illustrating the operation of the medication device 1. Fig. 6 is an explanatory diagram illustrating the operation of the medication device 1.

[0021] The medication device according to this embodiment will be described below with reference to Figures 1 to 6. Note that in all of the following drawings, the dimensions and proportions of the components have been appropriately changed to make the drawings easier to understand.

[0022] [Medication Device] Fig. 1 is a schematic perspective view showing a medication device 1 of this embodiment. Fig. 2 is an exploded perspective view of the medication device 1. Fig. 3 is a schematic perspective view of a sliding part 11 (sliding part main body 12) of the medication device 1.

[0023] 1 to 3, medication device 1 includes injection section 10 and guide section 20. A portion of injection section 10 is inserted into through-hole 20x of guide section 20. Before use, injection section 10 is supported by compression spring (elastic member) 30. Medication device 1 is attached to the skin of a living body and is used to continuously administer medicinal solution L supplied from external device 50 into the living body.

[0024] In this specification, when the medication device 1 is placed with the guide part 20 side on the ground, the normal direction to the contact surface of the guide part 20 is defined as the up-down direction of the medication device 1, and the injection part 10 side is referred to as the "upper" side and the guide part 20 side is referred to as the "lower" side of the medication device 1. Other expressions of "upper" and "lower" also refer to relative positions defined based on the same up-down direction.

[0025] In addition, in this specification, the term "plan view" refers to the field of view when the medication device 1 is viewed from above in the vertical direction.

[0026] <Injection Section> The injection section 10 is a cylindrical member that punctures the skin to inject the medicinal liquid L into the living body. The injection section 10 has a sliding section 11 and a puncturing section 15 having a microneedle 152.

[0027] (Sliding Part) The sliding part 11 is a cylindrical member having a flow path 10x formed therein through which the medicinal liquid L flows. The sliding part 11 has a sliding part main body 12 and a flow path member 13.

[0028] (Sliding Part Main Body) The sliding part main body 12 is a cylindrical member in which a part of the flow path 10x of the sliding part 11 is formed.

[0029] The sliding part body 12 has a through-hole 12x that constitutes a part of the flow path 10x. The through-hole 12x passes through the sliding part body 12 in the up-down direction. The through-hole 12x is formed by a first hole 12a from above, a second hole 12b having a smaller diameter than the first hole 12a, a third hole 12c having a larger diameter than the second hole 12b, and a fourth hole 12d having a tapered surface whose opening diameter gradually increases downward, all of which are connected to each other.

[0030] Due to the change in the inner diameter, an upper inner surface 12e is formed at the connection between the first hole 12a and the second hole 12b, and a lower inner surface 12f is formed at the connection between the second hole 12b and the third hole 12c of the sliding portion body 12.

[0031] An O-ring 14 is inserted into the through-hole 12x from above. The O-ring 14 is disposed on the inner upper surface 12e.

[0032] The sliding portion main body 12 has a cylindrical first member 121 and a second member 122 provided at the upper end of the first member 121 .

[0033] The outer surface of the first member 121 has a pair of flat surfaces 121x extending in the vertical direction and curved surfaces 121y that are part of a cylindrical surface and are continuous with the pair of flat surfaces 121x. The pair of flat surfaces 121x are arranged, for example, parallel to each other.

[0034] Each of the pair of flat surfaces 121x is provided with a substantially elliptical convex portion 121z.

[0035] The second member 122 is a ring-shaped structure (flange) in plan view provided above the first member 121. The second member 122 has a groove 12y provided in the radial direction and connected to the through-hole 12x.

[0036] (Flow path member) The flow path member 13 is a member that communicates with the through-hole 12x (part of the flow path) of the sliding part body 12, and is connectable to an external device 50 that supplies the medicinal solution L to the medication device 1. As the external device 50, for example, a small pump having a storage section (reservoir tank) for the medicinal solution L can be used.

[0037] The flow path member 13 has a through-hole 13x that constitutes a part of the flow path 10x. The flow path member 13 is connected in this order to a first tube 13a extending along the groove 12y of the sliding part body 12, a bent portion 13b that has an outer diameter larger than that of the first tube 13a and is bent at approximately 90°, a flange 13c, a second tube 13d that extends in the vertical direction, and a connecting portion 13e. One end of the through-hole 13x opens to the first tube 13a, and the other end opens to the connecting portion 13e.

[0038] The flow path member 13 is connected to the sliding part body 12 by inserting the connecting part 13e into the second hole 12b of the sliding part body 12. The connecting part 13e is a structural part formed in a truncated cone shape whose outer diameter gradually decreases downward, and has an upper surface 13g at the connection part with the second tube 13d. When the flow path member 13 is inserted into the sliding part body 12, the connecting part 13e is engaged with the inner lower surface 12f at the upper surface 13g.

[0039] Furthermore, in the flow path member 13, when the connecting portion 13e is inserted into the second hole 12b, the O-ring 14 is sandwiched between the lower surface 13f of the flange 13c and the inner upper surface 12e of the sliding portion main body 12. This makes it possible to suppress liquid leakage at the connection point between the sliding portion main body 12 and the flow path member 13.

[0040] The flow path member 13 is detachable from the sliding portion body 12. The flow path member 13 configured to be detachable from the sliding portion body 12 may be replaceable with another flow path member. In this case, the replaced flow path member may be the same as or different from the flow path member 13. A flow path member (second flow path member) different from the flow path member 13 is preferably configured to be connectable to, for example, an external device (second external device) different from the above-mentioned external device 50. In this way, by making the flow path member replaceable depending on the external device used, it is possible to connect to various external devices and administer the medicinal solution L. An example of the second external device is a syringe.

[0041] (Puncture section) The puncture section 15 is provided at the end (lower end 12g of the sliding section main body 12) of the sliding section 11. The puncture section 15 has a disk-shaped base 151 and a plurality of microneedles 152 extending downward from a lower surface 151a of the base 151.

[0042] The base 151 is a disk-shaped member having microneedles 152 provided on one surface. The base 151 is connected to the lower end 12g of the sliding part main body 12 with the microneedles 152 facing downward. The connection between the sliding part main body 12 and the base 151 is liquid-tight, preventing leakage of the drug solution L flowing inside.

[0043] The microneedles 152 have through-holes that communicate with the flow channel 10x. Specifically, the puncture section 15 has through-holes that penetrate the base 151 and the microneedles 152 and communicate with the flow channel 10x. The medication device 1 of this embodiment has four microneedles 152. The number of microneedles 152 may be less than four or more than four as long as the effects of the invention are not impaired.

[0044] In the puncture part 15, the base part 151 and the microneedle 152 are integrally molded. For example, a biodegradable plastic can be used as the material of the puncture part 15. An example of the biodegradable plastic is polyglycolic acid (PGA).

[0045] The biodegradable plastics are known to be susceptible to deterioration under humid and hot conditions. Therefore, when the puncture part 15 is made of biodegradable plastic, electron beam sterilization is a desirable method for sterilizing the injection part 10 or the sliding part 11. From this perspective, when the puncture part 15 is made of biodegradable plastic, it is desirable that the material of the injection part 10 or the sliding part 11 be a resin that can be sterilized by electron beam and has sufficient strength. Polystyrene is a suitable example of such a resin.

[0046] <Guide portion> Guide portion 20 has a through hole 20x into which injection portion 10 is inserted, and guides the sliding direction of injection portion 10 in through hole 20x. Guide portion 20 has guide portion main body 21, elastic body 22, and adhesive layer 23. Through hole 20x extends in the normal direction (vertical direction) of the lower surface (contact surface of guide portion 20) of adhesive layer 23.

[0047] (Guide Main Body) The guide main body 21 is a cylindrical member having a through hole 21x that constitutes part of the through hole 20x. The through hole 21x has a pair of flat surface portions 211x extending in the vertical direction and curved surface portions 212x that are part of the cylindrical surface and are continuous with the pair of flat surface portions 211x. The pair of flat surface portions 211x are arranged, for example, parallel to each other. Only one of the flat surface portions 211x is shown in FIG. 2 .

[0048] In a posture in which injection unit 10 is inserted into through hole 20x, flat surface portion 211x faces flat surface portion 121x of sliding unit 11. Similarly, curved surface portion 212x faces curved surface portion 121y of sliding unit 11. When injection unit 10 is inserted into through hole 20x, rotation in the circumferential direction about the axis of through hole 20x is restricted by flat surface portion 211x, and injection unit 10 slides while maintaining its posture in the circumferential direction.

[0049] A pair of flat surfaces 211x are each provided with a substantially elliptical recess 21z. A protrusion 121z formed on the side surface of injection part 10 (sliding part 11) fits into recess 21z. When injection part 10 is inserted to a height where protrusion 121z and recess 21z are aligned, protrusion 121z fits into recess 21z, thereby maintaining the posture of injection part 10. The combination of protrusion 121z and recess 21z corresponds to the "first holding structure" of the present invention.

[0050] The guide body 21 has a recess 21a on its lower surface 21d into which the elastic body 22 fits. The lower surface 21d of the guide body 21 corresponds to "one end side of the through hole in the guide body" in the present invention. The recess 21a has a circular ring shape in a plan view. Various shapes can be adopted for the recess 21a as long as it can fit and hold the elastic body 22.

[0051] The guide body 21 also has a recess 21b on the upper surface 21y that accommodates a portion of the compression spring 30.

[0052] The through-hole 21x, the recess 21a, and the recess 21b are formed concentrically in a plan view.

[0053] (Elastic Body) The elastic body 22 is provided on one end side (lower side) of the through hole 21x in the guide portion main body 21, and surrounds the periphery of the through hole 21x (through hole 20x) in plan view.

[0054] Here, when we say that the elastic body 22 "surrounds" the through hole 21x, we mean both a case in which the elastic body 22 is formed in a continuous ring shape to surround the through hole 21x, and a case in which the elastic body 22 is formed discretely (intermittently) around the through hole 21x to surround the through hole 21x.

[0055] The elastic body 22 preferably has a closed annular shape in a plan view. The elastic body 22 has a through-hole 22x that penetrates in the up-down direction. The through-hole 22x communicates with the through-hole 21x of the guide portion main body 21 and constitutes a part of the through-hole 20x.

[0056] The elastic body 22 has a first annular portion 221 that fits into the recess 21a, and a second annular portion 222 that is continuous with the first annular portion 221 on the inner circumferential side of the first annular portion 221. In the elastic body 22, the first annular portion 221 located on the outer circumferential side is thicker than the second annular portion 222 located on the inner circumferential side. In other words, the thickness H1 of the first annular portion 221 is greater than the thickness H2 of the second annular portion 222.

[0057] The elastic body 22 is replaceable. The replacement elastic body 22 may be a member having the same elastic modulus as the elastic body 22 currently in use, or may be a second elastic body having a different elastic modulus from the elastic body 22. Since the medication device 1 is replaceable with two or more types of elastic bodies 22 having different elastic moduli, an elastic body with an appropriate softness can be selected and used depending on the position where the medication device 1 is attached.

[0058] The elastic body 22 may be made of a material that is used for the core of a cosmetic puff, such as polyurethane, natural rubber, synthetic rubber, foamed polyethylene, polymer gel, ethylene-vinyl acetate copolymer resin, silicone resin, thermoplastic elastomer, or curable liquid silicone rubber (LSR).

[0059] (Adhesive Layer) The adhesive layer 23 is provided on the lower surface 22a of the elastic body 22, and surrounds the periphery of the through-hole 22x in plan view.

[0060] Here, when the adhesive layer 23 "surrounds" the through hole 22x, it includes both the case where the adhesive layer 23 is formed in a continuous ring shape to surround the through hole 22x, and the case where the adhesive layer 23 is formed discretely (intermittently) around the through hole 22x to surround the through hole 22x.

[0061] The adhesive layer 23 preferably has a closed annular shape in a plan view. The adhesive layer 23 has a through-hole 23x that penetrates in the vertical direction. The through-hole 23x communicates with the through-hole 22x of the elastic body 22 and constitutes a part of the through-hole 20x.

[0062] <Elastic Member (Second Retention Structure)> Compression spring (elastic member) 30 is provided between injection section 10 and guide section 20 and retains injection section 10. When compression spring 30 is not compressed (steady state), puncture section 15 of injection section 10 is housed inside through-hole 20x. Compression spring 30 corresponds to the "second retention structure" of the present invention, and the position of medication device 1 when compression spring 30 is in the steady state corresponds to the "second position" of the present invention.

[0063] Before use of the medication device 1, the compression spring 30 holds the injection part 10 in a position in which the puncture part 15 is housed inside the through-hole 20x. Furthermore, as will be described later, when using the medication device 1, the compression spring 30 generates an appropriate resistance when the user presses the injection part 10 to slide the injection part 10.

[0064] In this embodiment, the compression spring 30 is shown as the elastic member of the medication device 1, but this is not limiting. As long as the injection unit 10 can be held in the second position in which the puncture unit 15 is housed inside the through-hole 20x in the steady state, various elastic members other than the compression spring can be used as the elastic member.

[0065] For example, although the medication device 1 uses one compression spring 30 to hold the injection part 10, multiple compression springs may be used to hold the injection part 10. Also, instead of a compression spring, a known spring such as a disc spring or a leaf spring may be used.

[0066] Furthermore, for the purpose of holding injection unit 10 in the second position, second holding structure may be configured to hold injection unit 10 without having elastic force. As such a second holding structure, a jig (stopper) that is sandwiched between second member 122 of sliding unit main body 12 and guide unit 20 to hold injection unit 10 in the second position can also be used.

[0067] Alternatively, the second holding structure may be configured such that the diameter of first member 121 of sliding portion main body 12 is equal to the inner diameter of through hole 21x, and injection portion 10 is held by friction between first member 121 and the inner wall of through hole 21x. Alternatively, a protrusion may be provided on either or both of the outer wall of first member 121 and the inner wall of through hole 21x, and the protrusion may be used to increase the frictional force between first member 121 and through hole 21x, thereby holding injection portion 10.

[0068] 4 to 6 are explanatory diagrams illustrating the operation of the medication device 1. As shown in Fig. 4, when using the medication device 1, first, the medication device 1 is attached to the skin S of the animal to be punctured (e.g., the patient to be medicated) using the adhesive layer 23, and then the injection unit 10 is pressed down (reference symbol M1). The injection unit 10 slides through the through-hole 20x and is pressed down perpendicularly against the skin S of the subject with which the underside of the medication device 1 comes into contact.

[0069] When pressing down the injection part 10, the user of the medication device 1 (the patient to whom the medication is to be administered) may pinch the skin S between the underside of the medication device 1 and the user's fingers to fix the skin S.

[0070] Compression spring 30 pushes injection part 10 upward while the injection part 10 is being pressed down, so that injection part 10 moves downward by the distance pressed down by the user without dropping onto the skin S against the user's will.

[0071] After the microneedles 152 of the puncture unit 15 reach the skin S, when the injection unit 10 is further pressed down, the microneedles 152 puncture the skin S. As described above, since the injection unit 10 is pressed down almost perpendicular to the skin S of the subject, the microneedles 152 also puncture the skin S almost perpendicularly.

[0072] 5, when the injection unit 10 is further pressed down, the convex portion 121z (see FIG. 3) formed on the side surface of the injection unit 10 (sliding portion 11) fits into the concave portion 21z (see FIG. 2) in the through-hole 20x, thereby holding the injection unit 10 in a position (first position) in which the tip of the microneedle 152 protrudes beyond the adhesive layer 23.

[0073] The amount by which the tip of the microneedle 152 protrudes downward from the lower surface of the adhesive layer 23 in the first position (protrusion amount) can be controlled by the formation positions of the convex portion 121z and the concave portion 21z. For example, it is preferable that the convex portion 121z and the concave portion 21z are formed at positions where the protrusion amount is 0.1 mm or more and 10 mm or less.

[0074] With the medication device 1 attached to the skin S in this manner, the medicinal liquid L is supplied from the external device 50. The medicinal liquid L flows inside the flow channel 10x and is injected intracutaneously or subcutaneously via the through-holes of the microneedles 152.

[0075] The medication device 1 is used while it is attached to the skin S. Therefore, when a user of the medication device 1 moves around the area where the medication device 1 is attached, the skin S at the area where the medication device 1 is attached moves, and the surface shape of the skin S is thought to be deformed, as shown in Figure 6 .

[0076] Even in such a case, the medication device 1 is prevented from shifting position because it is attached to the skin S by the adhesive layer 23. Furthermore, the elastic body 22 deforms in accordance with the deformation of the skin S, so that the puncture section 15 (microneedle 152) can suitably maintain a state in which it is punctured into the skin S almost perpendicularly.

[0077] Furthermore, in order to maintain the state of the microneedles 152 when the skin S is deformed as described above, it is preferable that the elastic body 22 has a small amount of deformation on the inner periphery side close to the microneedles 152 in order to suppress misalignment of the microneedles 152. Furthermore, it is preferable that the elastic body 22 has a large amount of deformation in order to absorb deformation of the skin S.

[0078] In contrast, the elastic body 22 is formed so that the first annular portion 221 located on the outer periphery is thicker than the second annular portion 222 located on the inner periphery. This allows the amount of deformation of the elastic body 22 on the inner periphery to be smaller than the amount of deformation on the outer periphery. Furthermore, deformation of the skin S can be absorbed by the outer periphery (first annular portion 221) deforming more.

[0079] According to the medication device 1 configured as described above, the microneedles 152 are employed, and the medicinal liquid L can be continuously administered into a living body.

[0080] In the present embodiment, the elastic body 22 has a closed annular configuration including the first annular portion 221 and the second annular portion 222, but is not limited to this. The elastic body 22 may be configured with only the first annular portion 221.

[0081] Furthermore, the elastic body 22 is fitted into the recess 21 a of the guide body 21 and is replaceable, but this is not limiting and the elastic body 22 may be attached to the guide body 21 .

[0082] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on the design, specifications, etc., without departing from the spirit of the present invention.

[0083] DESCRIPTION OF SYMBOLS 1... medication device, 10... injection part, 10x... flow path, 11... sliding part, 12... sliding part main body, 12x, 13x, 20x, 21x, 22x, 23x... through holes, 13... flow path member, 20... guide part, 21... guide part main body, 21a, 21b, 21z... recess, 22... elastic body, 23... adhesive layer, 30... compression spring (elastic member), 50... external device, 121z... convex part, 152... microneedle, L... drug solution, S... skin

Claims

1. A medication device comprising: a cylindrical injection part that punctures the skin to inject a medicinal solution into a living body; and a guide part that has a through hole into which the injection part is inserted and that guides the sliding direction of the injection part in the through hole, wherein the injection part has a cylindrical sliding part that has a flow path formed therein through which the medicinal solution flows, and a microneedle that is provided at an end of the sliding part and communicates with the flow path, and the guide part has a guide part main body that has the through hole, an elastic body that is provided on one end side of the through hole in the guide part main body, and an adhesive layer that is provided on the surface of the elastic body, and at least one of the injection part and the guide part has a first holding structure that holds the injection part in a first position in which the tip of the microneedle protrudes beyond the adhesive layer.

2. The medication device according to claim 1, further comprising a second holding structure that holds the injection part in a second position in which the tip of the microneedle is housed within the through-hole.

3. The medication device according to claim 2, wherein the second holding structure is an elastic member provided between the injection portion and the guide portion, and holds the injection portion in the second position.

4. A medication device according to any one of claims 1 to 3, wherein the elastic body surrounds the periphery of the through hole.

5. The medication device according to claim 4, wherein the elastic body has a closed ring shape in plan view.

6. A medication device according to claim 4, wherein the elastic body is thicker on the outer periphery than on the inner periphery.

7. A medication device according to any one of claims 1 to 3, wherein the guide body has a recess at one end into which the elastic body fits.

8. A medication device according to any one of claims 1 to 3, wherein the elastic body is replaceable.

9. The medication device according to claim 8, further comprising a second elastic body having a different elastic modulus from that of the elastic body, as a part replaceable with the elastic body.

10. A medication device according to any one of claims 1 to 3, wherein the sliding part has a cylindrical sliding part body in which a part of the flow path is formed, and a flow path member that communicates with a part of the flow path of the sliding part body and is connectable to an external device that injects the medicinal liquid into the medication device, and the flow path member is detachable from the sliding part body.

11. The medication device according to claim 10, further comprising a second flow path member connectable to a second external device as a part replaceable with the flow path member.

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