Drug solution administration device

Abstract

To provide a drug solution administration device whose size can be reduced.SOLUTION: A drug solution administration device 10 includes a drug solution container 16, a gasket 18, a pusher 68, a feed screw shaft 70, a driving mechanism, a housing 14, and a rotation regulation part 26. The rotation regulation part 26 includes a first magnetic member 118 arranged outside the drug solution container, and a second magnetic member 120 provided on the pusher. At least one of the first magnetic member and the second magnetic member includes a magnet. The rotation regulation part regulates the rotation of the pusher by the magnetic force between the first magnetic member and the second magnetic member.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a chemical solution administration device.

Background Art

[0002] Patent Document 1 discloses a chemical solution administration device including a vial (chemical solution container), a stopper (gasket), a pusher, a feed screw shaft, a drive mechanism, and a battery. The gasket is slidably disposed inside the chemical solution container. The pusher is connected to the base end portion of the gasket. The feed screw shaft is screwed into a screw portion provided on the pusher to move the pusher in the tip direction. The drive mechanism includes a motor and rotates the feed screw shaft. The battery supplies power to the drive mechanism. In such a chemical solution administration device, the rotation of the pusher is restricted by the frictional force generated between the inner peripheral surface of the chemical solution container and the outer peripheral surface of the gasket, thereby preventing the pusher from rotating together with the feed screw shaft when the feed screw shaft is rotated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the chemical solution administration device described in Patent Document 1 as described above, when the dimensional error between the chemical solution container and the gasket is large, sufficient frictional force may not be generated to restrict the rotation of the pusher. When the frictional force between the chemical solution container and the gasket is insufficient, the pusher does not move in the tip direction due to the rotation of the feed screw shaft, and thus the chemical solution cannot be discharged from the chemical solution container. On the other hand, if the shapes and sizes of the chemical solution container and the gasket are designed so that sufficient frictional force is generated between the chemical solution container and the gasket even when the dimensional error between the chemical solution container and the gasket is large, the driving force required to move the gasket in the tip direction with respect to the chemical solution container increases. Then, since it is necessary to increase the sizes of the drive mechanism and the battery, there is a disadvantage that the chemical solution administration device becomes large.

[0005] An object of the present invention is to solve the above-described problems.

Means for Solving the Problems

[0006] One aspect of the present invention is a chemical solution administration device including: a cylindrical chemical solution container that stores a chemical solution and has a chemical solution discharge port at the tip; a gasket that is slidably and liquid-tightly disposed inside the chemical solution container; a pusher that presses the gasket in the tip direction; a feed screw shaft that has a second screw portion that engages with a first screw portion provided on the pusher and moves the pusher in the tip direction; a pressing mechanism including the above; a drive mechanism that is driven by power supply from a battery to rotate the feed screw shaft; and a housing that houses the chemical solution container, the feed screw shaft, and the drive mechanism, further including a rotation restricting portion that restricts the rotation of the pusher along the rotation direction of the feed screw shaft. In the initial state of the chemical solution administration device, the pusher is separated from the gasket, and the rotation restricting portion has a first magnetic member disposed outside the chemical solution container and a second magnetic member provided on the pusher, at least one of the first magnetic member and the second magnetic member includes a magnet, and the rotation restricting portion restricts the rotation of the pusher by the magnetic force between the first magnetic member and the second magnetic member.

Effects of the Invention

[0007] According to the present invention, since the rotation of the pusher along the rotation direction of the feed screw shaft is restricted by the rotation restricting portion (the magnetic force between the first magnetic member and the second magnetic member), the pusher can be efficiently moved in the tip direction by the rotation of the feed screw shaft. In this case, since it is not necessary to restrict the rotation of the pusher by the frictional force generated between the chemical solution container and the gasket, the frictional force can be reduced. As a result, the driving force required to move the gasket in the tip direction inside the chemical solution container can be reduced, so that the driving mechanism and the battery can be power-saving. Therefore, since the size of the driving mechanism and the battery can be reduced, the chemical solution administration device can be made small.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0009] As shown in FIG. 1, the chemical solution administration device 10 according to an embodiment of the present invention is used to administer a chemical solution M into a living body. The chemical solution administration device 10 continuously administers the chemical solution M filled in the chemical solution container 16 into the living body over a relatively long period of time (for example, about several minutes to several hours). The chemical solution administration device 10 may intermittently administer the chemical solution M into the living body. Examples of the chemical solution M include protein preparations, narcotic analgesics, diuretics, and the like.

[0010] When the chemical solution administration device 10 is in use, for example, a patch-type tube 402 with a needle is connected to the chemical solution administration device 10 as an administration instrument 400. The tube 402 with a needle injects the chemical solution M discharged from the chemical solution container 16 into the patient's body.

[0011] The tube 402 with a needle includes a connector 404, a liquid delivery tube 406, a patch portion 408, and a puncture needle 410. The connector 404 can be connected to the tip portion 40 (see FIG. 3) of the chemical solution container 16. The liquid delivery tube 406 has flexibility. One end of the liquid delivery tube 406 is connected to the connector 404. The other end of the liquid delivery tube 406 is connected to the patch portion 408. The patch portion 408 can be attached to the skin S. The puncture needle 410 protrudes from the patch portion 408. The puncture needle 410 is punctured substantially perpendicular to the skin S. Note that the puncture needle 410 may be punctured obliquely with respect to the skin S.

[0012] Note that the administration instrument 400 connected to the chemical solution administration device 10 is not limited to the above-described patch-type tube 402 with a needle, and for example, a structure in which a puncture needle (such as a winged needle) is connected to the tip of the liquid delivery tube 406 may be used.

[0013] As shown in FIGS. 1 to 4, the chemical solution administration device 10 includes a device main body 12 and a housing 14 that houses the device main body 12. The device main body 12 includes a chemical solution container 16, a gasket 18, a pressing mechanism 20, a driving mechanism 22, a battery 24, a rotation restricting portion 26, and a control portion 30.

[0014] As shown in FIGS. 3 and 4, the chemical solution container 16 is formed in a hollow cylindrical shape having a chemical solution chamber 32 inside. Specifically, the chemical solution container 16 has a body portion 34, a flange portion 36, a shoulder portion 38, and a tip portion 40. The body portion 34 extends in the axial direction (arrow X direction) of the chemical solution container 16. The inner diameter and outer diameter of the body portion 34 are constant (substantially constant) over the entire length of the body portion 34. A base end opening 42 is formed at the base end of the body portion 34.

[0015] The flange portion 36 projects radially outward from the base end (the end in the arrow X2 direction) of the body portion 34 and extends annularly. The shoulder portion 38 has a reduced diameter from the tip end (the end in the arrow X1 direction) of the body portion 34. The tip portion 40 projects in the tip direction from the radially inner end of the shoulder portion 38. A chemical solution discharge port 44 communicating with the chemical solution chamber 32 is formed in the tip portion 40. The chemical solution M is pre-filled inside the chemical solution container 16. The chemical solution container 16 is preferably made of a transparent material.

[0016] The chemical solution discharge port 44 is liquid-tightly sealed by a sealing member 46 made of an elastic resin material such as a rubber material or an elastomer material. The sealing member 46 is punctured by a needle 412 provided on the connector 404 when the connector 404 shown in FIG. 1 is connected to the tip portion 40. The sealing member 46 is fixed to the tip portion 40 of the chemical solution container 16 by a fixing cap 50 having an opening 48 at the tip. The tip surface of the sealing member 46 is exposed from the opening 48 of the fixing cap 50.

[0017] As shown in FIG. 5, the gasket 18 is slidably disposed inside the chemical solution container 16. The gasket 18 includes a gasket body 52 and a contact member 54.

[0018] The gasket body 52 is made of a first material having elasticity. The first material is an elastic resin material such as a rubber material or an elastomer material. The outer peripheral surface of the gasket body 52 is in liquid-tight contact with the inner peripheral surface of the body portion 34 of the chemical solution container 16. The gasket body 52 has a connection recess 56 that opens to the base end surface of the gasket body 52. A female thread 58 is formed on the inner peripheral surface of the connection recess 56. The tip portion of the gasket body 52 is tapered and its diameter is reduced in the tip direction.

[0019] The contact member 54 is made of a second material harder than the first material. The second material is a hard resin material or a metal material. The contact member 54 has a connection portion 60 and a contact main body 62. A male thread 64 that engages with the female thread 58 of the gasket body 52 is formed on the outer peripheral surface of the connection portion 60. The contact main body 62 protrudes radially outward from the base end of the connection portion 60. The contact main body 62 extends annularly along the circumferential direction of the connection portion 60. The contact main body 62 has a flat pressed surface 66 facing the base end direction of the chemical solution container 16. The contact member 54 is spaced apart from the inner peripheral surface of the body portion 34.

[0020] The pressing mechanism 20 presses the gasket 18 in the tip direction (arrow X1 direction). When the gasket 18 moves (advances) in the tip direction, the chemical solution M in the chemical solution chamber 32 is pushed out from the chemical solution discharge port 44.

[0021] The pressing mechanism 20 has a plunger 68 and a feed screw shaft 70. In the initial state of the chemical solution administration device 10, the tip portion of the plunger 68 is inserted into the chemical solution container 16. The plunger 68 includes a cylindrical pressing plunger 72 and an intermediate plunger 74 disposed inside the pressing plunger 72. That is, the plunger 68 has a telescopic structure that can be extended in the axial direction.

[0022] In FIGS. 5 and 6, the pressing plunger 72 is injection-molded, for example, from a resin material. The pressing plunger 72 extends along the axial direction of the chemical solution container 16. The pressing plunger 72 has a plunger main body 76, a tip flange portion 78, and a base end flange portion 80. The plunger main body 76 is formed in a cylindrical shape. A female screw 84 is formed at the base end portion of the inner peripheral surface of the plunger main body 76 (see FIG. 5).

[0023] As shown in FIG. 6, the tip flange portion 78 protrudes radially outward from the tip end portion of the plunger main body 76. The tip flange portion 78 extends in an annular shape in the circumferential direction of the plunger main body 76. The outer diameter (diameter) of the tip flange portion 78 is smaller than the inner diameter of the barrel portion 34 of the chemical solution container 16.

[0024] The tip flange portion 78 has a thin-walled portion 78a and a thick-walled portion 78b. The length of the thin-walled portion 78a along the circumferential direction of the plunger main body 76 is longer than the length of the thick-walled portion 78b along the circumferential direction of the plunger main body 76. The thick-walled portion 78b includes an outer surface 79 facing the bottom portion of the housing 14 (facing the direction of arrow Z2). The thick-walled portion 78b is located directly below the axis of the pressing plunger 72 (in the direction of arrow Z2) (see FIG. 7).

[0025] The tip flange portion 78 supports the tip end portion of the pressing plunger 72 in a predetermined posture inside the chemical solution container 16. In other words, the tip flange portion 78 suppresses the axis of the pressing plunger 72 from being excessively inclined with respect to the axis of the chemical solution container 16 inside the chemical solution container 16.

[0026] The base end flange portion 80 protrudes radially outward from the base end portion of the plunger main body 76. The base end flange portion 80 extends in an annular shape in the circumferential direction of the plunger main body 76. The outer diameter (diameter) of the base end flange portion 80 is smaller than the inner diameter of the barrel portion 34 of the chemical solution container 16.

[0027] The proximal flange portion 80 supports the proximal end portion of the pressing plunger 72 in a predetermined posture inside the chemical solution container 16. In other words, the proximal flange portion 80 suppresses the excessive inclination of the axis of the pressing plunger 72 with respect to the axis of the chemical solution container 16 inside the chemical solution container 16. The size and shape of the proximal flange portion 80 are the same as those of the distal flange portion 78. Note that the size and shape of the proximal flange portion 80 may be different from those of the distal flange portion 78.

[0028] The distal end surface of the pressing plunger 72 includes a pressing surface 90 for pressing the pressed surface 66 (see FIG. 5) of the gasket 18 in the distal end direction (arrow X1 direction). The pressing surface 90 is a flat surface extending in a direction orthogonal to the axial direction of the pressing plunger 72. In the initial state of the chemical solution administration device 10, the pressing surface 90 is separated from the gasket 18 (see FIG. 5).

[0029] As shown in FIG. 5, the intermediate plunger 74 is formed in a cylindrical shape. In the initial state of the chemical solution administration device 10, the distal end of the intermediate plunger 74 does not project in the distal end direction from the distal end (pressing surface 90) of the pressing plunger 72. The intermediate plunger 74 is separated from the chemical solution container 16.

[0030] On the outer peripheral surface of the intermediate plunger 74, a male thread 96 that engages with the female thread 84 of the pressing plunger 72 is formed. The male thread 96 is not formed at the distal end portion of the outer peripheral surface of the intermediate plunger 74. In other words, the tip of the male thread 96 is located in the proximal end direction (arrow X2 direction) from the tip of the intermediate plunger 74. Therefore, the pressing plunger 72 does not come out of the intermediate plunger 74 in the distal end direction. Note that the proximal end of the male thread 96 is located at the proximal end of the intermediate plunger 74. A female thread 98 is formed at the proximal end portion of the inner peripheral surface of the intermediate plunger 74.

[0031] The feed screw shaft 70 has a rod portion 100 and a connecting portion 102. The rod portion 100 is formed in a cylindrical shape. In the initial state of the chemical solution administration device 10, the tip of the rod portion 100 does not protrude in the tip direction beyond the tip of the pressing plunger 72 (pressing surface 90). On the outer peripheral surface of the rod portion 100, a male screw 104 that engages with the female screw 98 of the intermediate plunger 74 is formed.

[0032] On the tip portion of the outer peripheral surface of the rod portion 100, the male screw 104 is not formed. In other words, the tip of the male screw 104 is located in the base end direction (arrow X2 direction) relative to the tip of the feed screw shaft 70. Therefore, the intermediate plunger 74 does not come out of the rod portion 100 in the tip direction. Note that the base end of the male screw 104 is located at the base end of the rod portion 100. The connecting portion 102 is connected to the base end of the rod portion 100. A driven gear 112, which will be described later, of the drive mechanism 22 is connected to the connecting portion 102.

[0033] Such a pressing mechanism 20 has a female screw 98 (first screw portion) of the intermediate plunger 74, a male screw 104 (second screw portion) of the feed screw shaft 70, a male screw 96 (third screw portion) of the intermediate plunger 74, and a female screw 84 (fourth screw portion) of the pressing plunger 72. In the pressing mechanism 20, the frictional resistance between the female screw 84 of the pressing plunger 72 and the male screw 96 of the intermediate plunger 74 is greater than the frictional resistance between the male screw 104 of the feed screw shaft 70 and the female screw 98 of the intermediate plunger 74.

[0034] In FIGS. 2 and 3, the drive mechanism 22 has a motor 106, a drive gear 108, an intermediate gear 110, a driven gear 112, and a drive circuit 113. The motor 106 rotates the drive gear 108. The motor 106 is disposed on the side (arrow Y1 direction) of the pressing mechanism 20. The drive gear 108 is fixed to the output shaft 114 of the motor 106.

[0035] The intermediate gear 110 is arranged in the direction of arrow Y2 of the drive gear 108 so as to mesh with the drive gear 108. The driven gear 112 is arranged in the direction of arrow Y2 of the intermediate gear 110 so as to mesh with the intermediate gear 110. The drive gear 108, the intermediate gear 110, and the driven gear 112 are arranged side by side in a direction (arrow Y direction) perpendicular to the axial direction of the feed screw shaft 70.

[0036] As shown in FIG. 5, a fitting hole 116 into which the connecting portion 102 is fitted is formed in the central portion of the driven gear 112. The connecting portion 102 and the fitting hole 116 have a shape (non-circular shape) such that the driven gear 112 and the feed screw shaft 70 rotate integrally.

[0037] In FIG. 3, the drive circuit 113 is a circuit for driving the motor 106. The drive circuit 113 is arranged, for example, above the motor 106 (in the direction of arrow Z1). The drive circuit 113 may be located in the direction of arrow Y1 of the motor 106.

[0038] In FIGS. 2 and 3, the battery 24 is a power source that supplies power to the motor 106 and the control unit 30. The battery 24 may be either a primary battery or a secondary battery. The battery 24 is arranged on the side (in the direction of arrow Y1) of the chemical solution container 16. Also, the battery 24 is located in the direction of arrow X1 of the motor 106.

[0039] As shown in FIGS. 5 and 7, the rotation restricting portion 26 restricts the rotation of the pusher 68 along the rotation direction of the feed screw shaft 70 (arrow R direction in FIG. 7). The rotation restricting portion 26 has a first magnetic member 118 and a second magnetic member 120.

[0040] The first magnetic member 118 is a ferromagnetic material. The first magnetic member 118 is, for example, an iron-based alloy. However, the first magnetic member 118 may be cobalt, nickel, or an alloy thereof. The first magnetic member 118 is arranged on a container support portion 184 (to be described later) of the housing 14 so as to contact or be close to the outer surface of the body portion 34 of the chemical solution container 16.

[0041] The first magnetic member 118 extends linearly along the axial direction of the chemical solution container 16. For example, the first magnetic member 118 extends from the tip of the body portion 34 to the flange portion 36. Note that the first magnetic member 118 does not protrude in the proximal direction from the chemical solution container 16. The first magnetic member 118 has a constant (substantially constant) width W over its entire length. The width W of the first magnetic member 118 is smaller than the outer diameter of the body portion 34 of the chemical solution container 16.

[0042] The second magnetic member 120 is a magnet. Specifically, the second magnetic member 120 is a permanent magnet. Examples of the second magnetic member 120 include alnico magnets, ferrite magnets, rare earth magnets, rubber magnets, and plastic magnets.

[0043] The second magnetic member 120 is provided at the tip of the plunger 68. Specifically, the second magnetic member 120 is provided at the tip of the pressing plunger 72. The second magnetic member 120 is fitted into a recess 81 formed on the outer surface 79 (the surface facing the direction of arrow Z2) of the thick portion 78b of the tip flange portion 78. The second magnetic member 120 has, for example, a circular shape (see FIG. 6). The diameter D of the second magnetic member 120 is the same (substantially the same) as the width W of the first magnetic member 118 (see FIG. 7).

[0044] The size, shape, position, etc. of the first magnetic member 118 and the second magnetic member 120 can be set as appropriate. The diameter D of the second magnetic member 120 may be larger or smaller than the width W of the first magnetic member 118.

[0045] In the present embodiment, as shown in FIG. 7, the feed screw shaft 70 rotates counterclockwise (in the direction of arrow R) when viewed from the proximal direction (in the direction of arrow X2) of the feed screw shaft 70. Therefore, a torque in the direction of arrow R acts on the pressing plunger 72. At this time, since the first magnetic member 118 and the second magnetic member 120 are attracted to each other by magnetic force (magnetic attraction force), the rotation of the pressing plunger 72 along the rotation direction of the feed screw shaft 70 is blocked.

[0046] As shown in FIG. 8, the control unit 30 includes an arithmetic unit 162 and a storage unit 164. The arithmetic unit 162 is constituted by a processor (processing circuit) such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), for example.

[0047] The arithmetic unit 162 includes a motor control unit 168. The arithmetic unit 162 realizes the motor control unit 168 by executing a program stored in the storage unit 164. Note that the arithmetic unit 162 may realize at least a part of the motor control unit 168 by an integrated circuit. Examples of the integrated circuit include an ASIC (Application Specific Integrated Circuit) and an FPGA (Field-Programmable Gate Array).

[0048] The storage unit 164 includes a volatile memory and a non-volatile memory. Examples of the volatile memory include a RAM (Random Access Memory). This volatile memory is used as a working memory of the processor, and data and the like necessary for processing or arithmetic operations are temporarily stored. Examples of the non-volatile memory include a ROM (Read Only Memory) and a flash memory. This non-volatile memory is used as a storage memory. Programs, tables, maps, and the like are stored in the non-volatile memory. At least a part of the storage unit 164 may be incorporated in the above-described processor or integrated circuit. The motor control unit 168 controls the movement of the motor 106 by controlling the drive circuit 113.

[0049] As shown in FIG. 1, the housing 14 includes a chassis structure 170 and a housing main body 172. As shown in FIGS. 2 and 3, a chemical solution container 16, a pressing mechanism 20, a drive mechanism 22, and a rotation restricting unit 26 (see FIG. 4) are fixed to the chassis structure 170. The chassis structure 170 has a chassis main body member 174, a stopper member 176, and a bearing member 178.

[0050] The chassis body member 174 has a base plate portion 180, an outer wall portion 182, a container support portion 184, and a motor support portion 186. The base plate portion 180 forms the bottom of the chassis body member 174. In other words, the base plate portion 180 forms a part of the bottom of the housing 14. The outer wall portion 182 protrudes upward (in the direction of arrow Z1) from the outer edge portion of the base plate portion 180.

[0051] In FIG. 7, the container support portion 184 protrudes upward from the base plate portion 180 and supports the body portion 34 of the chemical solution container 16 from below (in the direction of arrow Z2). A groove 188 for arranging the first magnetic member 118 is formed on the surface of the container support portion 184 facing the body portion 34. That is, the first magnetic member 118 is located between the chemical solution container 16 and the base plate portion 180 (the bottom of the housing 14). In other words, the first magnetic member 118 is located directly below the axis of the chemical solution container 16 (in the direction of arrow Z2).

[0052] As shown in FIGS. 2, 3, and 7, the motor support portion 186 protrudes upward from the base plate portion 180 and supports the motor 106. The motor 106 and the drive circuit 113 are arranged to be spaced apart in the direction of arrow Y1 that is orthogonal to the thickness direction (arrow Z direction) of the base plate portion 180 and the axial direction (arrow X direction) of the chemical solution container 16 with respect to the chemical solution container 16 (see FIGS. 2 and 3). The motor support portion 186 includes a wall portion 189 located between the chemical solution container 16 and the motor 106. The wall portion 189 is located between the second magnetic member 120 and the motor 106. The wall portion 189 shields the magnetism of the second magnetic member 120.

[0053] In FIGS. 2 and 3, the stopper member 176 is attached to the base plate portion 180 in a state of covering the body portion 34 of the chemical solution container 16 from above (in the direction of arrow Z1). When the flange portion 36 of the chemical solution container 16 comes into contact, the stopper member 176 prevents the chemical solution container 16 from moving in the direction of arrow X1 with respect to the chassis body member 174. The bearing member 178 rotatably supports the feed screw shaft 70 in a state of being attached to the base plate portion 180 (see FIG. 3).

[0054] In FIG. 1, the housing body 172 houses the chassis structure 170. Further, the housing body 172 houses the device body 12 (chemical solution container 16, gasket 18, pressing mechanism 20, drive mechanism 22, battery 24, rotation restricting portion 26, and control portion 30). A window portion 190 is provided in the housing body 172 for visually recognizing the remaining amount of the chemical solution M in the chemical solution container 16. Note that the tip portion 40 of the chemical solution container 16 protrudes from the housing body 172 in the direction of arrow X1. Therefore, the fixed cap 50 is exposed outside the housing body 172.

[0055] Next, the operation of the chemical solution administration device 10 during use will be described. In the initial state, as shown in FIG. 3, the pressing surface 90 of the pressing plunger 72 is located farther in the proximal direction (arrow X2 direction) than the pressed surface 66 of the gasket 18 in the chemical solution administration device 10. Thereby, the chemical solution M filled in the chemical solution container 16 can be maintained in a sterile state. When administering the chemical solution M in the chemical solution administration device 10, the motor control portion 168 controls the drive circuit 113 to drive the motor 106. When the motor 106 is driven, the rotational driving force of the motor 106 is transmitted to the driven gear 112 via the drive gear 108 and the intermediate gear 110.

[0056] When the driven gear 112 rotates, as shown in FIG. 9, since the feed screw shaft 70 rotates, torque acts on the pusher 68. In the present embodiment, the rotation of the pressing plunger 72 along the rotation direction of the feed screw shaft 70 is restricted by the rotation restricting portion 26. Specifically, the rotation of the pressing plunger 72 along the rotation direction of the feed screw shaft 70 is restricted by the magnetic force (magnetic attraction force) between the first magnetic member 118 and the second magnetic member 120. Therefore, when the feed screw shaft 70 rotates, the female screw 98 of the intermediate plunger 74 moves in the tip direction with respect to the male screw 104 of the feed screw shaft 70. In other words, the pusher 68 (pressing plunger 72 and intermediate plunger 74) linearly moves in the tip direction with respect to the feed screw shaft 70.

[0057] Then, the pressing surface 90 of the plunger 68 contacts the surface 66 of the gasket 18 to be pressed, and the gasket 18 is pressed in the tip direction by the plunger 68. As a result, the gasket 18 moves in the tip direction within the chemical solution container 16, and the chemical solution M in the chemical solution container 16 is administered into the living body through the chemical solution discharge port 44 and the administration device 400. The movement of the plunger 68 is detected by a movement detection sensor (not shown). The movement detection sensor is, for example, an encoder that detects the rotation of the drive gear 108. Further, the control unit 30 calculates the movement amount of the plunger 68 based on the output signal of the movement detection sensor.

[0058] When the female screw 98 of the intermediate plunger 74 is positioned at the tip of the male screw 104 of the feed screw shaft 70, the rotation of the intermediate plunger 74 with respect to the feed screw shaft 70 is restricted. Therefore, as shown in FIG. 10, the intermediate plunger 74 rotates together with the feed screw shaft 70. Then, the pressing plunger 72 linearly moves in the tip direction with respect to the intermediate plunger 74. As a result, the pressing of the gasket 18 in the tip direction by the pressing mechanism 20 is continued. The motor control unit 168 stops the drive of the motor 106 when the movement amount of the plunger 68 calculated by the control unit 30 reaches the target value.

[0059] This embodiment has the following effects.

[0060] According to this embodiment, since the rotation of the plunger 68 along the rotation direction of the feed screw shaft 70 is restricted by the rotation restricting portion 26 (the magnetic force between the first magnetic member 118 and the second magnetic member 120), the plunger 68 can be efficiently moved in the tip direction by the rotation of the feed screw shaft 70. In this case, since it is not necessary to restrict the rotation of the plunger 68 by the frictional force generated between the chemical solution container 16 and the gasket 18, the frictional force can be reduced. As a result, the driving force required to move the gasket 18 in the tip direction inside the chemical solution container 16 can be reduced, so that the driving mechanism 22 and the battery 24 can be power-saving. Therefore, since the sizes of the driving mechanism 22 and the battery 24 can be reduced, the chemical solution administration device 10 can be made small.

[0061] The rotation restricting unit 26 restricts the rotation of the plunger 68 by the magnetic attraction force between the first magnetic member 118 and the second magnetic member 120.

[0062] According to such a configuration, the rotation of the plunger 68 along the rotation direction of the feed screw shaft 70 can be efficiently restricted by the magnetic attraction force.

[0063] The first magnetic member 118 extends along the axial direction of the chemical solution container 16.

[0064] According to such a configuration, the plunger 68 can be stably moved in the tip direction of the chemical solution container 16.

[0065] The second magnetic member 120 is located at the tip of the plunger 68. In the initial state of the chemical solution administration device 10, the tip of the plunger 68 is inserted into the chemical solution container 16 so that the chemical solution container 16 is located between the first magnetic member 118 and the second magnetic member 120.

[0066] According to such a configuration, the chemical solution container 16 can suppress the first magnetic member 118 and the second magnetic member 120 from coming into contact with each other by magnetic force.

[0067] The first magnetic member 118 is located between the bottom of the housing 14 and the chemical solution container 16. The second magnetic member 120 is provided on the surface (outer surface 79) of the plunger 68 facing the bottom of the housing 14.

[0068] According to such a configuration, the configuration of the chemical solution administration device 10 can be simplified.

[0069] The drive mechanism 22 includes a motor 106 for rotating the feed screw shaft 70 and a drive circuit 113 for driving the motor 106. The motor 106 and the drive circuit 113 are arranged to be separated from the chemical solution container 16 in a direction orthogonal to the thickness direction of the bottom of the housing 14 and the axial direction of the chemical solution container 16.

[0070] According to such a configuration, since the motor 106 and the drive circuit 113 can be arranged at positions away from the magnet of the rotation control unit 26, the magnetic influence received by the motor 106 and the drive circuit 113 from the magnet can be reduced.

[0071] The housing 14 has a wall portion 189 located between the chemical liquid container 16 and the motor 106.

[0072] According to such a configuration, the magnetic influence received by the motor 106 and the drive circuit 113 from the magnet of the rotation control unit 26 can be further reduced by the wall portion 189 located between the chemical liquid container 16 and the motor 106.

[0073] The first magnetic member 118 is a ferromagnetic material, and the second magnetic member 120 is a magnet.

[0074] According to such a configuration, since the magnet is located inside the chemical liquid container 16, the magnetic influence on the electronic components (such as the motor 106 and the drive circuit 113) arranged outside the chemical liquid container 16 can be efficiently suppressed.

[0075] The plunger 68 includes an intermediate plunger 74 and a pressing plunger 72. The intermediate plunger 74 has an internal thread 98 (first thread portion) and an external thread 96 (third thread portion). The pressing plunger 72 has an internal thread 84 (fourth thread portion) that engages with the external thread 96 and presses the gasket 18. The tip of the external thread 104 (second thread portion) of the feed screw shaft 70 is located in the base end direction relative to the tip of the feed screw shaft 70. The second magnetic member 120 is provided on the pressing plunger 72. The intermediate plunger 74 moves in the tip direction with respect to the feed screw shaft 70 by the rotation of the feed screw shaft 70, and rotates together with the feed screw shaft 70 in a state where the internal thread 98 of the intermediate plunger 74 is located at the tip of the external thread 104 of the feed screw shaft 70. The pressing plunger 72 moves in the tip direction with respect to the intermediate plunger 74 by the rotation of the intermediate plunger 74.

[0076] According to such a configuration, since the plunger 68 is configured to be stretchable, the length of the chemical solution administration device 10 along the axial direction of the chemical solution container 16 can be shortened. Thereby, the chemical solution administration device 10 can be further miniaturized.

[0077] The intermediate plunger 74 is separated from the chemical solution container 16.

[0078] According to such a configuration, since no frictional force is generated between the chemical solution container 16 and the intermediate plunger 74, the driving force required to move the gasket 18 in the tip direction can be efficiently reduced.

[0079] This embodiment is not limited to the above-described configuration. The first magnetic member 118 may be a magnet, and the second magnetic member 120 may be a ferromagnetic material. Further, both the first magnetic member 118 and the second magnetic member 120 may be magnets. A groove in which the first magnetic member 118 is disposed may be formed on the outer peripheral surface of the chemical solution container 16. In this case, since the thickness of the portion of the chemical solution container 16 located between the first magnetic member 118 and the second magnetic member 120 can be made relatively thin, the magnetic force (magnetic attraction force) between the first magnetic member 118 and the second magnetic member 120 can be increased.

[0080] The rotation restricting portion 26 may have a plurality of first magnetic members 118 arranged along the axial direction of the chemical solution container 16. In this case, each first magnetic member 118 does not have to extend along the axial direction of the chemical solution container 16. That is, each first magnetic member 118 may be formed in a circular shape, for example. Further, the adjacent first magnetic members 118 may be in contact with or separated from each other.

[0081] The rotation restricting portion 26 may have a plurality of first magnetic members 118 arranged at intervals in the circumferential direction of the chemical solution container 16 and a plurality of second magnetic members 120 arranged apart from each other in the circumferential direction of the plunger 68. In this case, the plurality of first magnetic members 118 and the plurality of second magnetic members 120 are arranged to face each other with the wall portion of the chemical solution container 16 interposed therebetween. According to such a configuration, the rotation of the plunger 68 (pressing plunger 72) along the rotation direction of the feed screw shaft 70 can be further suppressed.

[0082] Each of the first magnetic member 118 and the second magnetic member 120 is a magnet, and the rotation restricting portion 26 may restrict the rotation of the plunger 68 along the rotation direction of the feed screw shaft 70 by the magnetic repulsive force between the first magnetic member 118 and the second magnetic member 120.

[0083] The plunger 68 is not limited to a double cylinder structure in which the intermediate plunger 74 is disposed inside the pressing plunger 72, and may be a multi-cylinder structure with three or more plungers. The plunger 68 is not limited to a telescopic structure. The plunger 68 may be formed only by the pressing plunger 72. In this case, the female screw 84 of the pressing plunger 72 is screwed into the male screw 104 of the feed screw shaft 70.

[0084] This embodiment discloses the following content.

[0085] The above embodiment includes a cylindrical chemical solution container 16 that stores a chemical solution (M) and has a chemical solution discharge port (44) at the tip, a gasket (18) that is disposed in a slidable and liquid-tight manner inside the chemical solution container, a plunger (68) that presses the gasket in the tip direction, a feed screw shaft (70) that has a second screw portion (104) screwed into a first screw portion (98) provided on the plunger and moves the plunger in the tip direction, a pressing mechanism (20); a drive mechanism (22) that is driven by power supply from a battery (24) to rotate the feed screw shaft; and a housing (14) that houses the chemical solution container, the feed screw shaft, and the drive mechanism. The chemical solution administration device (10) further includes a rotation restricting portion (26) that restricts the rotation of the plunger along the rotation direction of the feed screw shaft. In the initial state of the chemical solution administration device, the plunger is separated from the gasket. The rotation restricting portion has a first magnetic member (118) disposed outside the chemical solution container and a second magnetic member (120) provided on the plunger. At least one of the first magnetic member and the second magnetic member includes a magnet. The rotation restricting portion restricts the rotation of the plunger by the magnetic force between the first magnetic member and the second magnetic member, and discloses a chemical solution administration device.

[0086] In the above-described chemical solution administration device, the rotation restricting portion may restrict the rotation of the plunger by the magnetic attraction force between the first magnetic member and the second magnetic member.

[0087] In the above-described chemical solution administration device, the first magnetic member may extend along the axial direction of the chemical solution container.

[0088] In the above-described chemical solution administration device, the second magnetic member is located at the tip of the plunger, and in the initial state of the chemical solution administration device, the tip of the plunger may be inserted into the chemical solution container such that the peripheral wall portion of the chemical solution container is located between the first magnetic member and the second magnetic member.

[0089] In the above-described chemical solution administration device, the first magnetic member is provided between the bottom of the housing and the chemical solution container, and the second magnetic member may be provided on the surface (79) of the plunger facing the bottom of the housing.

[0090] In the above-described chemical solution administration device, the drive mechanism includes a motor (106) for rotating the feed screw shaft and a drive circuit (113) for driving the motor, and the motor and the drive circuit may be arranged to be spaced apart in a direction orthogonal to the thickness direction of the bottom of the housing and the axial direction of the chemical solution container with respect to the chemical solution container.

[0091] In the above-described chemical solution administration device, the housing may have a wall portion (189) located between the chemical solution container and the motor.

[0092] In the above-described chemical solution administration device, the first magnetic member may be a ferromagnetic material, and the second magnetic member may be the magnet.

[0093] In the above-described chemical solution administration device, the first magnetic member may contain an iron-based alloy.

[0094] In the above-described chemical solution administration device, the pusher includes an intermediate plunger (74) having the first screw portion and the third screw portion (96), and a pressing plunger (72) having a fourth screw portion (84) screwed to the third screw portion and pressing the gasket. The tip of the second screw portion is located closer to the base end than the tip of the feed screw shaft. The second magnetic member is provided on the pressing plunger. The intermediate plunger moves in the tip direction with respect to the feed screw shaft by the rotation of the feed screw shaft, and rotates together with the feed screw shaft in a state where the first screw portion is located at the tip of the second screw portion. The pressing plunger may move in the tip direction with respect to the intermediate plunger by the rotation of the intermediate plunger.

[0095] In the above-described chemical solution administration device, the intermediate plunger may be separated from the chemical solution container.

[0096] Note that the present invention is not limited to the above-described disclosure, and various configurations can be adopted without departing from the gist of the present invention.

Explanation of Reference Numerals

[0097] 10... Chemical solution administration device 14... Housing 16... Chemical solution container 18... Gasket 20... Pressing mechanism 22... Driving mechanism 24... Battery 26... Rotation restricting portion 44... Chemical solution discharge port 68... Pusher 70... Feed screw shaft 72... Pressing plunger 74... Intermediate plunger 84... Female screw (fourth screw portion) 96... Male screw (third screw portion) 98... Female screw (first screw portion) 104... Male screw (second screw portion) 106... Motor 113... Driving circuit 118... First magnetic member 120... Second magnetic member 189... Wall portion M... Chemical solution

Claims

1. A cylindrical chemical solution container that stores a chemical solution and has a chemical solution discharge port at its tip, A gasket that is slidably and liquid-tightly disposed inside the chemical solution container, A pusher that presses the gasket in the tip direction, and a feed screw shaft that has a second screw portion that engages with a first screw portion provided on the pusher and moves the pusher in the tip direction, including a pressing mechanism, A drive mechanism that is driven by power supply from a battery to rotate the feed screw shaft, A chemical solution administration device including a housing that houses the chemical solution container, the feed screw shaft, and the drive mechanism, The chemical solution administration device further includes a rotation restricting portion that restricts rotation of the pusher along the rotation direction of the feed screw shaft, In the initial state of the chemical solution administration device, the pusher is separated from the gasket, The rotation restricting portion, A first magnetic member disposed outside the chemical solution container, A second magnetic member provided on the pusher, At least one of the first magnetic member and the second magnetic member includes a magnet, The rotation restricting portion restricts rotation of the pusher by magnetic force between the first magnetic member and the second magnetic member, a chemical solution administration device.

2. The chemical solution administration device according to claim 1, The rotation restricting portion restricts rotation of the pusher by magnetic attraction force between the first magnetic member and the second magnetic member, a chemical solution administration device.

3. The chemical solution administration device according to claim 1 or 2, The first magnetic member extends along the axial direction of the chemical solution container, a chemical solution administration device.

4. The chemical solution administration device according to any one of claims 1 to 3, The second magnetic member is located at the tip of the pusher, In the initial state of the chemical solution administration device, the tip of the pusher is inserted into the chemical solution container so that the peripheral wall portion of the chemical solution container is located between the first magnetic member and the second magnetic member, a chemical solution administration device.

5. The chemical solution administration device according to any one of claims 1 to 4, The first magnetic member is provided between the bottom of the housing and the chemical solution container, The second magnetic member is provided on the surface of the pusher facing the bottom of the housing, a chemical solution administration device.

6. The chemical solution administration device according to claim 5, The drive mechanism, A motor for rotating the feed screw shaft, A drive circuit for driving the motor, The motor and the drive circuit are spaced apart from the chemical solution container in a direction orthogonal to the thickness direction of the bottom of the housing and the axial direction of the chemical solution container, the chemical solution administration device.

7. The chemical solution administration device according to claim 6, wherein the housing has a wall portion located between the chemical solution container and the motor, the chemical solution administration device.

8. The chemical solution administration device according to any one of claims 1 to 7, wherein the first magnetic member is a ferromagnetic material, and the second magnetic member is the magnet, the chemical solution administration device.

9. The chemical solution administration device according to claim 8, wherein the first magnetic member contains an iron-based alloy, the chemical solution administration device.

10. The chemical solution administration device according to any one of claims 1 to 9, wherein the armature includes an intermediate plunger having the first threaded portion and the third threaded portion, and a pressing plunger having a fourth threaded portion screwed onto the third threaded portion and pressing the gasket, wherein the tip of the second threaded portion is located in the proximal direction with respect to the tip of the feed screw shaft, the second magnetic member is provided on the pressing plunger, the intermediate plunger moves in the tip direction with respect to the feed screw shaft by the rotation of the feed screw shaft, and rotates together with the feed screw shaft in a state where the first threaded portion is located at the tip of the second threaded portion, and the pressing plunger moves in the tip direction with respect to the intermediate plunger by the rotation of the intermediate plunger, the chemical solution administration device.

11. The chemical solution administration device according to claim 10, wherein the intermediate plunger is spaced apart from the chemical solution container, the chemical solution administration device.

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