Drug administration device

Abstract

[Problem] To provide a liquid medicine administration device capable of more accurately detecting the administration status of a liquid medicine. [Solution] A liquid medicine administration device 100 has: a presser 130 for pushing out a liquid medicine charged in a liquid medicine container 110; a drive mechanism 140 for moving the pressor forward and backward relative to a distal end opening of the liquid medicine container; and a control unit 150 for controlling the operation of the drive mechanism. The drive mechanism has: a motor 141 for generating driving force for moving the presser forward and backward; and a rotation detection unit 144 for detecting the rotation of the motor. The control unit has an operation confirming function for confirming the operation status of the motor on the basis of the detection result from the rotation detection unit. After confirming that the motor is stopped by the operation confirming function, the control unit drives reverse rotation of the motor to determine whether or not the presser moves backward.

Description

[Technical field]

[0001] The present invention relates to a drug solution administration device. [Background technology]

[0002] A syringe pump type drug administration device that administers a drug solution filled in a drug solution container into a living body by the pressing action of a plunger has been known. The drug solution administration device has a drive mechanism equipped with a motor that generates a drive force, and a control unit that controls the drive mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-181869 A Summary of the Invention [Problem to be solved by the invention]

[0004] A drug solution administration device administers a drug solution to a living body by a drive mechanism that advances a plunger little by little. Therefore, when the plunger stops, administration of the drug solution also stops. However, in the case of a drug solution administration device that determines that administration of the drug solution is complete when the motor stops (the plunger stops), there is a possibility that administration of the drug solution is determined to be complete even when the motor stops due to an abnormality (e.g., a motor failure) that occurs within the device.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a medicinal solution administration device that detects the administration status of a medicinal solution more accurately. [Means for solving the problem]

[0006] The drug solution administration device of the present invention includes a drug solution container filled with a drug solution, a pusher for pushing out the drug solution in the drug solution container, a gasket disposed at a tip of the plunger, slidable against an inner wall of the drug solution container and separated from the plunger; A drug solution administration device having a drive mechanism that moves the plunger back and forth relative to a tip opening of the drug solution container, and a control unit that controls an operation of the drive mechanism, The tip of the pusher pushes the gasket, thereby pushing out the liquid medicine in the liquid medicine container, the pusher separates from the gasket and retreats, and when the gasket is released from the pressure of the pusher, the amount of increase in the thickness of the gasket caused by the gasket returning from a compressed state to a non-compressed state is defined as a push-back amount L1, the amount of movement of the gasket due to the increased pressure applied to the liquid medicine remaining in the liquid medicine container and the supply path is defined as a push-back amount L3, and the sum of the push-back amount L1 and the push-back amount L3 is defined as a push-back amount L2, The drive mechanism has a motor that generates a drive force for moving the plunger forward and backward, and a rotation detection unit that detects the rotation of the motor, and the control unit has an operation confirmation function that confirms the operation status of the motor based on the detection result of the rotation detection unit, and after confirming that the motor has stopped by the operation confirmation function, the control unit starts the motor in reverse rotation to determine whether the plunger will move backward. If the motor does not rotate in reverse, it is determined that an administration abnormality has occurred. If the motor rotates in reverse, the motor is rotated backward by a return amount L, which is a distance by which the plunger is moved from the current position toward the base end by the reverse rotation of the motor, and then the motor is rotated forward to determine whether or not the plunger has hit the gasket based on the current value flowing through the motor or the rotation speed of the motor. If the plunger has hit the gasket, it is determined that an obstruction has occurred. If the plunger has not hit the gasket, it is determined that administration of the medicinal liquid in the medicinal liquid container has been completed, and the return amount L is greater than the push-back amount L1 and less than the push-back amount L2. . Effect of the Invention

[0007] According to the medicinal liquid administration device of the present invention, after confirming that the motor has stopped, the control unit starts the motor in reverse rotation to determine whether the plunger will move backward. This allows the control unit to check the operating status of the motor and determine whether an abnormality in administration of medicinal liquid has occurred due to a motor failure. Therefore, the medicinal liquid administration device can more accurately detect the administration status of the medicinal liquid. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a side view of the drug solution administration system according to the present embodiment. [Diagram 2] FIG. 1 is a diagram illustrating a typical example of use of the drug solution administration system according to the present embodiment. [Diagram 3] 1 is a schematic perspective view of a chemical liquid administration device constituting a chemical liquid administration system according to an embodiment of the present invention. [Figure 4] FIG. 2 is an exploded perspective view of the drug solution administration device according to the present embodiment. [Diagram 5] FIG. 2 is a partial cross-sectional view of the distal end side of the drug solution administration device according to the embodiment. [Figure 6] FIG. 2 is a block diagram of a control system of the drug solution administration device according to the present embodiment. [Figure 7] FIG. 2 is a diagram showing a schematic diagram of a rotation detection unit and the like. [Figure 8A] 4 is a cross-sectional view of the drug solution administration device showing a stopped state of the plunger when administration is completed and a state in which the plunger has been moved backwards. FIG. [Figure 8B]1 is a cross-sectional view of a medicinal liquid administration device showing a stopped state of a plunger and a rearwardly moved state of the plunger during abnormal administration (when a supply path is blocked). FIG. [Figure 9] 4 is a flowchart illustrating an operation of a control unit in the present embodiment. [Figure 10] 10 is an operation flowchart of a control unit in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0010] 1 to 8B are diagrams illustrating a medicinal liquid administration system 10, a medicinal liquid administration device 100, and an administration instrument 200 according to an embodiment. Arrow X in each diagram indicates the "longitudinal direction (longitudinal direction of the medicinal liquid container 110)" of the medicinal liquid administration device 100, arrow Y indicates the "width direction (depth direction)" of the medicinal liquid administration device 100, and arrow Z indicates the "height direction" of the medicinal liquid administration device 100.

[0011] (Chemical solution administration system) The drug solution administration system 10 is used for administering a drug solution into a living body. As shown in FIG.

[0012] 2, the drug solution administration device 100 and the administration instrument 200 are configured as a patch type that is attached to the user's body surface (skin) H. The part of the user's body to which the drug solution administration device 100 and the administration instrument 200 are attached is not particularly limited, but may be, for example, the abdomen or thigh.

[0013] The drug solution administration system 10 can continuously administer a drug solution (not shown) filled in a drug solution container 110 provided in the drug solution administration device 100 into a living body over a relatively long period of time (for example, several minutes to several hours) by a pressing action of a plunger 130 described later. The drug solution administration system 10 may also administer the drug solution into a living body intermittently.

[0014] (Medicine administration device) As shown in Figures 3 and 4, the drug solution administration device 100 has a drug solution container 110 in which the drug solution is filled, a housing 120 that holds the drug solution container 110, a pusher 130 that pushes out the drug solution in the drug solution container 110, a drive mechanism 140 that moves the pusher 130 back and forth relative to the tip opening of the drug solution container 110, a control unit 150 that controls the operation of the drive mechanism 140, and a power supply unit 160.

[0015] As shown in Figures 3 and 4, housing 120 has a box-shaped housing main body 121 with an internal storage space, a chassis 122 that is accommodated in the storage space of housing main body 121 and can be fixed to housing main body 121, and a cover member 123 that is attached to housing main body 121 with chassis 122 accommodated in the storage space.

[0016] As shown in Figures 3 to 5, a packing C is fitted into the opening of housing body 121. As shown in Figure 5, packing C is in linear contact with drug solution container 110 in the circumferential direction. For ease of explanation, Figure 5 shows only housing body 121 and packing C in cross section.

[0017] 3 and 4, a window 124 that allows the interior of the storage space to be viewed from the outside of the housing 120 is formed on the upper surface 121a of the housing main body 121. The window 124 is formed by providing a transparent or semi-transparent portion in part of the housing main body 121.

[0018] As shown in Fig. 4, a base end opening 125 for inserting chassis 122 into the accommodation space of housing main body 121 is formed on the base end side in the longitudinal direction of housing main body 121. As shown in Fig. 3 and Fig. 4, base end opening 125 of housing main body 121 is closed by cover member 123 with chassis 122 accommodated in the accommodation space.

[0019] 4, a sheet-like adhesive part (not shown) that can be attached to a body surface H of a user is provided on the bottom surface 121b of the housing main body 121. In the initial state before the drug solution administration device 100 is attached to the user, a peelable protective sheet is attached to the adhesive surface of the adhesive part.

[0020] Chassis 122 holds liquid medicine container 110, plunger 130, drive mechanism 140, control unit 150, and power supply unit 160.

[0021] The liquid medicine container 110 is a so-called prefilled type liquid medicine container. Therefore, the liquid medicine is pre-filled in the inner cavity 111 of the liquid medicine container 110. Examples of the liquid medicine include protein preparations, narcotic analgesics, diuretics, and the like.

[0022] A sealing member (not shown) for preventing leakage of the liquid medicine is disposed at a tip opening (discharge port) formed in tip portion 112 of liquid medicine container 110. As shown in Fig. 3, tip portion 112 of liquid medicine container 110 is disposed so as to protrude to the outside from housing body portion 121. In addition, an attachment portion 115 for connection to a tube 240 (see Fig. 1) described later is attached to the tip portion of liquid medicine container 110 protruding from housing body portion 121.

[0023] As shown in Fig. 4, a plunger 130 is inserted into the inner cavity 111 of the liquid medicine container 110. A gasket 131 capable of sliding against the inner wall 110a (see Figs. 8A and 8B) of the liquid medicine container 110 is disposed at the tip of the plunger 130. The gasket 131 seals the base end side of the gasket 131 liquid-tightly by bringing the outer periphery of the gasket 131 into liquid-tight contact with the inner periphery of the liquid medicine container 110. The gasket 131 can be advanced by advancing the plunger 130 in the longitudinal direction X and the tip of the plunger 130 pushing the gasket 131, but there is no mechanical connection between the plunger 130 and the gasket 131, and when the plunger 130 is moved backward in the opposite direction, the plunger 130 and the gasket 131 are separated from each other.

[0024] When the plunger 130 advances while the gasket 131 is stopped in the liquid medicine container 110, the gasket 131 is compressed in the direction in which the plunger 130 advances (longitudinal direction X). When the gasket 131 is compressed, the thickness in the longitudinal direction X decreases compared to when it is not compressed. The state in which the gasket 131 is stopped in the liquid medicine container 110 means, for example, a state in which the administration of the liquid medicine is completed and the gasket 131 abuts against the inner wall 110b at the tip side of the liquid medicine container 110 (see the upper diagram of FIG. 8A), or a state in which the supply path of the liquid medicine in the liquid medicine administration system 10 (such as the administration instrument 200) is blocked and the gasket 131 abuts against the liquid medicine remaining in the liquid medicine container 110 (see the upper diagram of FIG. 8B). The gasket 131 can be made of, for example, a flexible resin material such as a rubber material or an elastomer.

[0025] The drive mechanism 140 includes a motor 141 that receives a drive current from a power supply unit 160 and generates a drive force for moving the plunger 130 forward and backward, a reduction mechanism 142 equipped with gears or the like that transmits the rotational drive force of the motor 141, a feed screw 143 connected to the reduction mechanism 142, and a rotation detection unit 144 that detects the rotation of the motor 141.

[0026] The feed screw 143 converts the rotational motion transmitted from the reduction mechanism 142 into linear motion, and moves the plunger 130 forward and backward in the longitudinal direction X.

[0027] The feed screw 143 is screwed into the vicinity of the base end of the plunger 130. The feed screw 143 converts the rotational motion transmitted from the speed reducing mechanism 142 into linear motion, and moves the plunger 130 forward and backward in the longitudinal direction X. The plunger 130 advances toward the tip side of the drug solution container 110, thereby advancing the gasket 131, and pushes the drug solution from the inner cavity 111 of the drug solution container 110 into the tube 240 (see FIG. 1 ).

[0028] The rotation detection unit 144 is an encoder provided at the tip of the motor 141. As shown in Figs. 6 and 7, the encoder is composed of a photointerrupter 144a having an optical sensor and a slit plate 144b in which a number of slits are formed radially. The slit plate 144b rotates with the rotation of the motor 141. The rotation detection unit 144 can detect the rotation of the motor 141 by detecting the presence or absence of light passing through the slits of the slit plate 144b with the optical sensor of the photointerrupter 144a. Note that, in this embodiment, an encoder using the photointerrupter 144a as the rotation detection unit 144 is exemplified, but an encoder using a magnetic sensor may also be used. In addition, the position of the rotation detection unit 144 is not limited to the position exemplified in Figs. 6 and 7, and the rotation detection unit 144 may be placed between the motor 141 and the reduction mechanism 142 to directly detect the rotation of the motor 141.

[0029] The control unit 150 controls the liquid medicine delivery operation of the liquid medicine administration device 100. The control unit 150 can be configured, for example, by a known microcomputer (electronic circuit element) equipped with a CPU, RAM, ROM, etc. The control unit 150 comprehensively controls the operation of the drive mechanism 140 and the power supply unit 160.

[0030] The power supply unit 160 can be configured, for example, from a known button battery.

[0031] The control unit 150 is electrically connected to the power supply unit 160, the motor 141, and the rotation detection unit 144. The motor 141 rotates by the power supplied from the power supply unit 160, and the rotation speed of the motor 141 is controlled by the control unit 150 based on the detection result of the rotation detection unit 144.

[0032] In the drug solution administration device 100, the control unit 150 advances the plunger 130 (gasket 131) within the drug solution container 110, thereby administering the drug solution to the living body. At this time, the control unit 150 rotates the motor 141 in the forward direction. On the other hand, when the gasket 131 stops against the plunger 130 attempting to advance, the drug solution is no longer sent out from the drug solution container 110, and administration of the drug solution stops. Based on the detection result of the rotation detection unit 144, etc., the control unit 150 can confirm that the motor 141 has stopped in conjunction with the stop of the gasket 131.

[0033] In the medicinal liquid administration device 100, the control unit 150 performs the checking operation shown in Figures 9 and 10 after checking that the motor 141 has stopped, thereby enabling the medicinal liquid administration status to be detected more accurately. The checking operation of the control unit 150 will be described later.

[0034] Next, the function of the control unit 150 will be described.

[0035] The control unit 150 has an operation confirmation function that confirms the operation status of the motor 141 based on the detection result of the rotation detection unit 144. When the motor 141 is started (forward rotation or reverse rotation) and the rotation detection unit 144 detects the rotation of the motor 141 (presence or absence of light passing through), the control unit 150 can determine that the motor 141 is operating. On the other hand, when the motor 141 is started (forward rotation or reverse rotation) and the rotation detection unit 144 does not detect the rotation of the motor 141, the control unit 150 can determine that the motor 141 is stopped. Note that, in this embodiment, an encoder using a photointerrupter 144a is exemplified as the rotation detection unit 144, but an encoder using a magnetic sensor may be used.

[0036] Furthermore, the control unit 150 can detect the number of rotations of the motor 141 by using an operation checking function.

[0037] The control unit 150 has a rotation speed calculation function that calculates the rotation speed of the motor 141 based on the detection result of the rotation detection unit 144. When administration of the medicinal liquid is started, the control unit 150 can calculate the rotation speed of the motor 141 based on the interval of rotation (presence or absence of light passing) of the motor 141 detected by the rotation detection unit 144. When the current flowing through the motor 141 is constant, the rotation speed of the motor 141 has a characteristic that it decreases as the load increases (the torque increases) and increases as the load decreases. In addition, the control unit 150 has a current value measurement function that measures the current flowing through the motor 141. When the rotation speed of the motor 141 is constant, the current value flowing through the motor 141 has a characteristic that it increases as the load increases (the torque increases) and decreases as the load decreases.

[0038] The control unit 150 can maintain the rotation speed of the motor 141 at a preset speed (medicinal liquid administration speed) while the medicinal liquid is being administered by increasing the current flowing through the motor 141 when the rotation speed of the motor 141 decreases, and by decreasing the current flowing through the motor 141 when the rotation speed of the motor 141 increases, using the rotation speed calculation function. On the other hand, when the administration of the medicinal liquid is completed or an abnormality occurs in the administration of the medicinal liquid, the rotation speed of the motor 141 cannot be maintained at the medicinal liquid administration speed even if the current flowing through the motor 141 is increased, and finally the maximum value of the current that can be passed through the motor 141 is reached, and the rotation speed of the motor 141 decreases. Therefore, the control unit 150 can determine that the gasket 131 is stopped in the medicinal liquid container 110 when the rotation speed of the motor 141 falls below the medicinal liquid administration speed using the rotation speed calculation function, or when the current value of the motor 141 reaches a maximum value using the current value measurement function. In order to quickly determine whether gasket 131 has stopped within drug solution container 110, it may be determined that gasket 131 has stopped within drug solution container 110 when the rotational speed of motor 141 reaches a set value that is a predetermined amount smaller than the drug solution administration rate, or when the current value of motor 141 reaches a set value that is a predetermined amount smaller than the maximum value.

[0039] (Administration Equipment) As shown in FIGS. 1 and 2, the administration instrument 200 is configured to be connectable to the drug solution administration device 100 .

[0040] The administration device 200 has a connector 210, a needle tube 220 to be inserted into a living body, a puncture section (cannula housing) 230, a tube 240, and a puncture assistance tool 250 that assists the needle tube 220 in puncturing the living body.

[0041] The connector 210 is configured to be connectable to the medicinal liquid administration device 100 via an attachment part 215 fixed to the connector 210. The attachment part 215 can be connected to the medicinal liquid administration device 100 by being fitted onto an attachment part 115 (see FIG. 4 ) provided on the tip part 112 of the medicinal liquid container 110 protruding outside the housing 120.

[0042] A connecting needle portion (not shown) capable of piercing a sealing member (not shown) disposed at the tip portion 112 of the liquid medicine container 110 is disposed inside the mounting portion 215. The tube 240 is communicated with the inner cavity 111 of the liquid medicine container 110 via the connecting needle portion.

[0043] A flow path (not shown) that communicates the inner cavity of tube 240 and needle tube 220 is formed inside puncture portion 230. The medicinal liquid sent to puncture portion 230 via tube 240 is administered into the living body through the flow path formed inside puncture portion 230 and needle tube 220.

[0044] When the medicinal liquid is delivered to the user, a puncture assisting tool 250 is attached to the puncture section 230. The puncture assisting tool 250 holds an introduction needle (inner needle) 251. With the puncture assisting tool 250 attached to the puncture section 230, the introduction needle 251 is inserted through the inner cavity of the needle tube 220 and its tip protrudes from the tip of the needle tube 220. By inserting the introduction needle 251 into the needle tube 220 and puncturing the living body with the needle tube 220, the user can insert the needle tube 220 into the living body while preventing the needle tube 220 from being broken or the like.

[0045] After the needle tube 220 has been inserted into the living body, the puncture assistance tool 250 is removed from the puncture section 230. When the puncture assistance tool 250 is removed from the puncture section 230, the introduction needle 251 is removed from the inner cavity of the needle tube 220.

[0046] After needle tube 220 has been inserted into the living body, puncture assistant tool 250 is removed, and needle tube 220 is left in the living body with puncture section 230 remaining on the user's body surface H. In this state, plunger 130 of drug solution administration device 100 advances within drug solution container 110, whereby the drug solution filled in drug solution container 110 is delivered to the lumen of needle tube 220 via the flow path of tube 240 and puncture section 230.

[0047] The introduction needle 251 can be made of, for example, a metal needle, and the needle tube 220 can be made of, for example, a tubular member (cannula) made of resin.

[0048] Like the drug solution administration device 100, the administration device 200 is configured as a patch type that is attached to a user's body surface H when used. A sheet-like adhesive part (not shown) that can be attached to the body surface H is provided on the contact surface (bottom surface) 231 of the puncture part 230 of the administration device 200. In the initial state before the administration device 200 is attached to the user, a peelable protective sheet is attached to the adhesive surface of the adhesive part.

[0049] First Embodiment The checking operation of the control unit 150 in this embodiment will be described with reference to Fig. 9. Fig. 9 is a flowchart showing the operation of the control unit 150 in this embodiment.

[0050] As described above, the checking operation of the control unit 150 is performed after the administration of the medicinal liquid is started and the control unit 150 checks that the motor 141 has stopped (administration of the medicinal liquid has stopped) using the operation checking function. At this time, the control unit 150 may stop the activation of the motor 141 after checking that the motor 141 has stopped.

[0051] First, the control unit 150 sets a first rotation speed and a second rotation speed of the motor 141 corresponding to the push-back amounts L1 and L2 of the gasket 131.

[0052] (Push-back amount L1) When administration of the liquid medicine is completed, the gasket 131 stops in a state where it abuts against the inner wall 110b on the tip side of the liquid medicine container 110, as shown in the upper diagram of FIG. 8A. When the gasket 131 is released from the pressure of the plunger 130 by the backward movement of the plunger 130, the thickness of the gasket 131 increases from the compressed state reduced by the pressure, and returns to the original non-compressed state. Therefore, when the gasket 131 is released from the pressure of the plunger 130, the position of the base end 131b moves further toward the base end side without changing the position of the tip end 131a (see the lower diagram of FIG. 8A). In this specification, the increase in the thickness of the gasket 131 caused by the gasket 131 returning from the compressed state to the non-compressed state when the gasket 131 is released from the pressure of the plunger 130 is referred to as the push-back amount L1.

[0053] (Push-back amount L2) When the supply path is blocked (administration is abnormal), the gasket 131 stops in a state where it hits the medicinal liquid remaining at the tip end side of the medicinal liquid container 110, as shown in the upper diagram of Fig. 8B. At this time, the gasket 131 is in a compressed state, and the pressure applied to the medicinal liquid container 110 and the medicinal liquid remaining in the supply path is higher than the pressure on the base end 131b side of the gasket 131. When the gasket 131 is released from the pressure of the plunger 130 by the backward movement of the plunger 130, the gasket 131 returns from the compressed state to the uncompressed state, thereby increasing its thickness, and the increased pressure applied to the medicinal liquid container 110 and the medicinal liquid remaining in the supply path moves the gasket 131 toward the base end side (see the lower diagram of Fig. 8B). In this specification, the amount of increase in the thickness of gasket 131 caused by gasket 131 returning from a compressed state to a non-compressed state when gasket 131 is released from the pressure of plunger 130 is referred to as push-back amount L1 when administration of the medicinal liquid is completed. Also, the amount of movement of gasket 131 caused by the increased pressure applied to medicinal liquid container 110 and the medicinal liquid remaining in the supply path is referred to as push-back amount L3. And the sum of push-back amount L1 and push-back amount L3 is referred to as push-back amount L2.

[0054] The values ​​of the push-back amounts L1 and L2 of the gasket 131 may be set in advance. Also, the values ​​of the first rotation speed and the second rotation speed of the motor 141 may be set in advance.

[0055] Then, the control unit 150 starts measuring time (S100), and starts the motor 141 to rotate in reverse at a preset speed (push backward speed) based on the operation time or the third rotation speed of the motor 141 that is set in accordance with the return amount L of the pusher 130 (see FIG. 8A) (S101). At this time, the control unit 150 sets the return amount L of the pusher 130.

[0056] The return amount L of the plunger 130 refers to the distance by which the plunger 130 is moved from its current position toward the base end side by rotating the motor 141 in the reverse direction, and is set taking into consideration the return amounts L1 and L2 of the gasket 131.

[0057] In this embodiment, the return amount L of the pusher 130 is set to a value larger than the return amount L2 of the gasket 131.

[0058] Regardless of whether administration is completed or an abnormality occurs in administration, the base end 131b of the gasket 131 does not move from the stopped position to the base end side by the push-back amount L2 when released from the pressure of the plunger 130. Therefore, when the control unit 150 sets the push-back amount L to a value larger than the push-back amount L2, it can move the tip of the plunger 130 backward to the base end side from the position of the base end 131b of the pushed-back gasket 131.

[0059] The return amount L of the pusher 130 and the value of the operation time or the third rotation number of the motor 141 corresponding to the return amount L of the pusher 130 may be set in advance. The operation time of the motor 141 corresponding to the return amount L of the pusher 130 means the time it takes for the pusher 130 to move the return amount L at the pusher retraction speed. The third rotation number of the motor 141 corresponding to the return amount L of the pusher 130 means the rotation number of the motor 141 required to move the pusher 130 by the return amount L. If the pusher retraction speed cannot be set faster than the speed at which the base end 131b of the gasket 131 moves, there is a possibility that the base end 131b of the gasket 131 and the pusher 130 may come into contact with each other, and the operation time of the motor 141 corresponding to the return amount L of the pusher 130 cannot be accurately measured, so the third rotation number corresponding to the return amount L of the pusher 130 is used.

[0060] Then, the control unit 150 starts the motor 141 to rotate in the reverse direction, and determines whether the plunger 130 moves backwards by using an operation confirmation function that confirms the operating state of the motor 141 based on the detection result of the rotation detection unit 144 (S102).

[0061] If the plunger 130 does not move backward (the motor 141 does not operate) (S102: NO), the control unit 150 determines that the motor 141 is broken. Then, the control unit 150 determines that an abnormality in administration of the medicinal liquid has occurred due to a breakdown in the motor 141 (S103). Note that if the plunger 130 does not move backward, a breakdown in the motor 141 and / or the reduction mechanism 142 is suspected, but in the following description, it will be described as a breakdown in the motor 141.

[0062] On the other hand, when the plunger 130 moves backward (the motor 141 operates) (S102: YES), the control unit 150 determines that an administration abnormality has occurred due to a factor other than a failure of the motor 141, or that administration of the medicinal liquid has been completed.

[0063] In this way, after confirming that motor 141 has stopped, control unit 150 starts motor 141 in reverse rotation to determine whether plunger 130 moves backward (step S102), thereby checking the operating status of motor 141 and determining whether an abnormality in medicinal liquid administration has occurred due to a failure of motor 141. This allows medicinal liquid administration device 100 to more accurately detect the administration status of medicinal liquid.

[0064] If the motor 141 is operating (S102: YES), the control unit 150 determines whether or not a time T1 (corresponding to a "predetermined time") has elapsed since the motor 141 started to rotate in reverse (S104).

[0065] Time T1 is set to be longer than the longer of the time taken for base end 131b of gasket 131, released from the pressure of plunger 130, to finish moving the push-back amount L1 or the time taken for base end 131b of gasket 131 to finish moving the push-back amount L2. Note that the value of time T1 may be set during the confirmation operation or may be set in advance.

[0066] If the time T1 has not elapsed since the reverse rotation of the motor 141 was started (S104: NO), the control unit 150 repeats step S104.

[0067] On the other hand, when the time T1 has elapsed since the motor 141 was rotated in the reverse direction (S104: YES), the control unit 150 rotates the motor 141 in the forward direction (S105). At this time, the control unit 150 rotates the motor 141 at a preset speed (push bar forward speed) using the rotation speed calculation function. In addition, the control unit 150 measures the fourth rotation speed (P4 shown in FIG. 9, hereinafter referred to as rotation speed P4) and the current value A1 of the motor 141 while the motor 141 is rotating in the forward direction using the operation confirmation function and the current value measurement function.

[0068] Then, the control unit 150 judges whether the current value A1 of the motor 141 measured by the current value measuring function is smaller than the threshold value A (S106). Note that the threshold value A is the upper limit current value for the pusher 130 to advance in an unloaded state (a state in which the pusher 130 is not in contact with the gasket 131). When the pusher 130 is in an unloaded state and the motor 141 is rotating at the pusher advancement speed, if the pusher 130 hits the gasket 131, the load on the motor 141 increases, and the current flowing through the motor 141 to maintain the pusher advancement speed becomes larger than the upper limit current value.

[0069] If the current value A1 of the motor 141 is smaller than the threshold value A (S106: YES), the control unit 150 determines that the pusher 130 has not hit the gasket 131 (the gasket 131 is stopped forward of the position of the pusher 130), and repeats step S106 to move the pusher 130 further forward.

[0070] On the other hand, if the current value A1 of the motor 141 is equal to or greater than the threshold value A (S106: NO), the control unit 150 determines that the tip end of the pusher 130 has hit the base end 131b of the gasket 131, stops the pusher 130 (stops the operation of the motor 141), and proceeds to step S107.

[0071] Then, when the current value A1 measured by the current value measurement function exceeds the threshold A (S106: NO), the control unit 150 judges whether or not the rotation number P4 measured by the operation check function is greater than the rotation number P (S107). The judgment in step S106 may be made based on the rotation speed of the motor 141, and the control unit 150 may judge whether or not the rotation number P4 measured by the operation check function is greater than the rotation number P when the measured rotation speed falls below a predetermined rotation speed (threshold) for judging a collision. The rotation number P4 is the value of the rotation number of the motor 141 from when the forward rotation of the motor 141 starts in step S105 to when the operation of the motor 141 is stopped in NO in step S106, and the rotation number P is the value obtained by subtracting the first rotation number from the third rotation number. Here, the third rotation speed refers to the rotation speed of motor 141 corresponding to the return amount L of plunger 130, and means the rotation speed of motor 141 required to move plunger 130 by the return amount L, and the first rotation speed refers to the rotation speed of motor 141 corresponding to the push-back amount L1 of gasket 131, and means the rotation speed of motor 141 required to move plunger 130 by the push-back amount L1.

[0072] When the rotation speed P4 of the motor 141 is equal to or smaller than the rotation speed P (S107: NO), the control unit 150 determines that the movement amount of the gasket 131 when released from the pressure of the plunger 130 is equal to or larger than the push-back amount L1. Therefore, the control unit 150 determines that the gasket 131 is pushed back by more than the distance when it returns from the compressed state to the uncompressed state, and determines that an abnormal administration of the medicinal liquid has occurred due to a blockage of the supply path (S108). Furthermore, the control unit 150 can determine the position of the gasket 131 that hits the plunger 130 from the rotation speed P4 of the motor 141, and can predict the degree of blockage of the supply path.

[0073] On the other hand, when the rotation speed P4 of the motor 141 is greater than the rotation speed P (S107: YES), the control unit 150 determines that the amount of movement of the gasket 131 when released from the pressure of the plunger 130 is less than the push-back amount L1. Therefore, the control unit 150 determines that the gasket 131 has not been pushed back by more than the distance required for returning from the compressed state to the uncompressed state, and determines that administration of the medicinal liquid is complete (S109).

[0074] The drug solution administration device 100 may have an alarm unit (not shown) that notifies the user when an abnormality in drug solution administration is detected. The alarm unit is, for example, an LED provided in the housing 120 of the drug solution administration device 100. The alarm unit can notify the user of an abnormality in drug solution administration by turning on or blinking the LED. The alarm unit may be a speaker provided in the housing 120 of the drug solution administration device 100, and the control unit 150 may sound the speaker to notify the user of an abnormality in drug solution administration. The alarm unit may also wirelessly notify an external mobile terminal or computer of an abnormality in drug solution administration.

[0075] As described above, the drug solution administration device 100 of this embodiment is a drug solution administration device having a pusher 130 that pushes out the drug solution in a drug solution container 110 filled with the drug solution, a drive mechanism 140 that moves the pusher 130 back and forth relative to the tip opening of the drug solution container 110, and a control unit 150 that controls the operation of the drive mechanism 140, where the drive mechanism 140 has a motor 141 that generates a drive force for moving the pusher 130 back and forth, and a rotation detection unit 144 that detects the rotation of the motor 141, and the control unit 150 has an operation confirmation function that confirms the operating status of the motor 141 based on the detection result of the rotation detection unit 144, and after confirming that the motor 141 has stopped using the operation confirmation function, the control unit 150 starts the motor 141 in reverse rotation to determine whether the pusher 130 will move backwards.

[0076] According to the medicinal liquid administration device 100, the control unit 150, after confirming that the motor 141 has stopped, starts the motor 141 in reverse rotation to determine whether the plunger 130 moves backward, thereby checking the operating status of the motor 141 and determining whether an abnormality in administration of the medicinal liquid has occurred due to a failure of the motor 141. This allows the medicinal liquid administration device 100 to more accurately detect the administration status of the medicinal liquid.

[0077] Moreover, the medicinal solution administration device 100 has a gasket 131 that is slidable on the inner wall 110a of the medicinal solution container 110 and is separated from the plunger 130, and the tip of the plunger 130 pushes the gasket 131 to push out the medicinal solution in the medicinal solution container 110. With this configuration, the gasket 131 is separated from the plunger 130 when the plunger 130 is moved backward.

[0078] Moreover, the control unit 150 causes the motor 141 to rotate in the reverse direction to move the plunger 130 backward, and then rotates the motor 141 in the forward direction to determine whether the plunger 130 has hit the gasket 131. By configuring in this manner, the medicinal liquid administration device 100 can more accurately detect the administration status of the medicinal liquid.

[0079] Further, the drug solution administration device 100 is a drug solution administration device having a drug solution container 110 filled with a drug solution, a gasket 131 that can slide on an inner wall 110a of the drug solution container 110, a pusher 130 that presses the gasket 131, a drive mechanism 140 that moves the pusher 130 back and forth relative to the tip opening of the drug solution container 110, and a control unit 150 that controls the operation of the drive mechanism 140, wherein the drive mechanism 140 has a motor 141 that generates a drive force for moving the pusher 130 back and forth, and a rotation detection unit 144 that detects the rotation of the motor 141, and the control unit 150 has an operation confirmation function that confirms the operating status of the motor 141 based on the detection result of the rotation detection unit 144, and after confirming that the motor 141 has stopped by the operation confirmation function, the control unit 150 rotates the motor 141 in the reverse direction to move the pusher 130 backward, and then rotates the motor 141 in the forward direction to determine whether the pusher 130 has hit the gasket 131. With this configuration, the medicinal liquid administration device 100 can detect the administration status of the medicinal liquid more accurately.

[0080] Furthermore, the control unit 150 judges whether the plunger 130 has hit the gasket 131 based on the current value A1 flowing through the motor 141 or the rotation speed of the motor 141. When the control unit 150 judges based on the current value A1 flowing through the motor 141, it can judge whether the current value has fallen below an upper limit current value (threshold value A) for the plunger 130 to advance in an unloaded state (a state in which the plunger 130 is not hitting the gasket 131). When the control unit 150 judges based on the rotation speed of the motor 141, it can judge whether the measured rotation speed has fallen below a predetermined rotation speed for judging hitting. This allows the medicinal solution administration device 100 to more accurately detect the administration status of the medicinal solution.

[0081] Furthermore, the control unit 150 judges whether the administration of the medicinal liquid in the medicinal liquid container 110 has been completed or whether a blockage has occurred, depending on whether the plunger 130 hits the gasket 131. This allows the medicinal liquid administration device 100 to more accurately detect the administration status of the medicinal liquid.

[0082] Moreover, the control unit 150 waits for the lapse of time T1 (predetermined time) or more after rotating the motor 141 in the reverse direction, and then rotates the motor 141 in the forward direction. This enables the medicinal liquid administration device 100 to more accurately detect the administration status of the medicinal liquid.

[0083] Moreover, the time T1 (predetermined time) is the time from when the motor 141 is rotated in the reverse direction until the movement of the gasket 131 stops. This enables the medicinal liquid administration device 100 to more accurately detect the administration status of the medicinal liquid.

[0084] Moreover, when the plunger does not move backward even when the motor is rotated in the reverse direction, it is determined that the motor has failed. This allows the medicinal liquid administration device 100 to more accurately detect the administration status of the medicinal liquid.

[0085] <Second embodiment> Next, a confirmation operation of the control unit 150 in the second embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart showing the operation of the control unit 150 in the second embodiment.

[0086] First, the control unit 150 sets a first rotation speed and a second rotation speed of the motor 141 corresponding to the push-back amounts L1 and L2 of the gasket 131. Note that the values ​​of the push-back amounts L1 and L2 or the first rotation speed and the second rotation speed may be set in advance.

[0087] The control unit 150 starts timing (S200), and starts the motor 141 to rotate in reverse at a preset pusher backward speed based on the operation time or the fifth rotation number of the motor 141 set in accordance with the second return amount of the pusher 130 so that the position of the pusher 130 moves toward the base end side by the second return amount from the current stop position (S201). At this time, the control unit 150 sets the second return amount of the pusher 130.

[0088] The second return amount of the plunger 130 is set to a value larger than the push-back amount L1 and smaller than the push-back amount L2 of the gasket 131. Therefore, when a blockage occurs in the supply path, the amount by which the gasket 131 is pushed back is larger than the second return amount of the plunger 130, and when administration of the medicinal liquid is completed, the amount by which the gasket 131 is pushed back is smaller than the second return amount of the plunger 130.

[0089] The second return amount of the pusher 130, and the value of the operation time or the fifth rotation number of the motor 141 corresponding to the second return amount of the pusher 130 may be set in advance. The operation time of the motor 141 corresponding to the second return amount of the pusher 130 means the time it takes for the pusher 130 to move the second return amount at the pusher backward speed. The fifth rotation number of the motor 141 corresponding to the second return amount of the pusher 130 means the rotation number of the motor 141 required to move the pusher 130 by the second return amount. If the pusher backward speed cannot be set faster than the speed at which the base end 131b of the gasket 131 moves, there is a possibility that the base end 131b of the gasket 131 and the pusher 130 may come into contact with each other, and the operation time of the motor 141 corresponding to the second return amount of the pusher 130 cannot be accurately measured, so the fifth rotation number corresponding to the second return amount of the pusher 130 is used.

[0090] Then, the control unit 150 starts the motor 141 to rotate in the reverse direction, and determines whether the plunger 130 moves backwards by using an operation checking function that checks the operating state of the motor 141 based on the detection result of the rotation detection unit 144 (S202).

[0091] If the plunger 130 does not move backward (the motor 141 does not operate) (S202: NO), the control unit 150 determines that the motor 141 is broken. Then, the control unit 150 determines that an abnormality in the administration of the medicinal liquid has occurred due to the breakdown of the motor 141 (S203).

[0092] On the other hand, when the motor 141 is operating (S202: YES), the control unit 150 determines that an administration abnormality has occurred due to a factor other than a malfunction of the motor 141, or that administration of the medicinal liquid has been completed.

[0093] In this way, after confirming that motor 141 has stopped, control unit 150 starts motor 141 in reverse rotation to determine whether plunger 130 moves backward (step S202), thereby checking the operating status of motor 141 and determining whether an abnormality in the administration of medicinal liquid has occurred due to a malfunction of motor 141.

[0094] If the motor 141 is operating (S202: YES), the control unit 150 determines whether or not a time T2 (corresponding to a "predetermined time") has elapsed since the motor 141 started to rotate in reverse (S204).

[0095] Time T2 is set to be longer than the longer of the time required for base end 131b of gasket 131, released from the pressure of plunger 130, to complete the movement of push-back amount L1 or push-back amount L2. Note that the value of time T2 may be set during the confirmation operation or may be set in advance.

[0096] If the time T2 has not elapsed since the reverse rotation of the motor 141 was started (S204: NO), the control unit 150 repeats step S204.

[0097] On the other hand, when the time T2 has elapsed since the motor 141 was rotated in the reverse direction (S204: YES), the control unit 150 rotates the motor 141 in the forward direction (S205). At this time, the control unit 150 uses the rotation speed calculation function to rotate the motor 141 at a preset speed. Note that the second return amount of the plunger 130 is set to a value larger than the push-back amount L1 and smaller than the push-back amount L2, and the time T2 is set to be longer than the longer of the time for the base end 131b of the gasket 131 released from the pressure of the plunger 130 to finish moving the push-back amount L1 or the push-back amount L2. Therefore, when a blockage occurs in the supply path, the base end 131b of the gasket 131 abuts against the tip side of the plunger 130 at the time when the time T2 has elapsed since the motor 141 was rotated in the reverse direction, and when administration is completed, the base end 131b of the gasket 131 does not abut against the tip side of the plunger 130. Furthermore, the control unit 150 uses the current value measurement function to measure the current value B1 immediately after the motor 141 is rotated in the forward direction.

[0098] Then, the control unit 150 determines whether the current value B1 of the motor 141 is smaller than the threshold value A (S206). Note that the control unit 150 may measure the rotation speed of the motor 141 and determine whether the rotation speed is smaller than a predetermined rotation speed (threshold value) for determining whether or not the motor 141 has reached a dead end.

[0099] When the current value B1 of the motor 141 (the current value immediately after the motor 141 rotates in the reverse direction) is equal to or greater than the threshold value A (S206: NO), the control unit 150 determines that the plunger 130 abuts against the gasket 131. Therefore, the control unit 150 determines that the movement amount (distance) of the gasket 131 when released from the pressure of the plunger 130 is equal to the second return amount. Then, the control unit 150 determines that the gasket 131 has been pushed back by more than the distance when returning from the compressed state to the uncompressed state, and determines that an abnormal administration of the medicinal liquid has occurred due to a blockage of the supply path (S207).

[0100] On the other hand, when the current value B1 of the motor 141 (the current value immediately after the motor 141 rotates in the reverse direction) is smaller than the threshold value A (S206: YES), the control unit 150 determines that the plunger 130 has not struck the gasket 131 stopped in the medicinal liquid container 110. Therefore, the control unit 150 determines that the movement amount (distance) of the gasket 131 when released from the pressure of the plunger 130 is smaller than the second return amount. Then, the control unit 150 determines that the gasket 131 has not been pushed back by more than the distance required for returning from the compressed state to the uncompressed state, and determines that administration of the medicinal liquid is complete (S208).

[0101] As described above, the control unit 150 according to the second embodiment has a current value measurement function for measuring the current value flowing through the motor 141, and the control unit 150 sets the second return amount for moving the plunger 130 backward after confirming that the motor 141 has stopped, the operation time of the motor 141 corresponding to the second return amount, and the time T2 (predetermined time) set longer than the operation time of the motor 141, and the control unit 150 rotates the motor 141 forward after the time T2 has elapsed since rotating the motor 141 in the reverse direction, and judges whether the current value B1 measured by the current value measurement function immediately after rotating the motor 141 forward is below the threshold value A (predetermined upper limit current value) or whether the rotation speed measured by the encoder is lower than the threshold value (predetermined upper limit rotation speed). As a result, the control unit 150 can judge whether the plunger 130 hits the gasket 131 and whether an abnormality in administration of the medicinal liquid occurs due to blockage of the supply path.

[0102] In addition, the plunger 130 has a gasket 131 disposed at the tip thereof and capable of sliding against the inner wall of the liquid medicine container 110, and the second return amount is set to a value greater than the push-back amount L1 and smaller than the push-back amount L2. Therefore, if a blockage occurs in the supply path, the gasket 131 hits the tip side of the plunger 130 before the plunger 130 moves forward following the backward movement. Therefore, the control unit 150 can determine whether or not an abnormality in the administration of the liquid medicine occurs due to a blockage in the supply path by determining whether or not the current value B1 of the motor 141 is below the threshold value A. In addition, by setting the second return amount of the plunger 130 to a value smaller than the push-back amount L2, the plunger 130 protrudes less from the liquid medicine container 110 due to the backward movement of the plunger 130, and therefore the size of the liquid medicine administration device 100 can be made smaller.

[0103] In addition, the amount of push-back (L1 shown in Figure 8B) due to the increase in thickness of gasket 131 from a compressed state to a non-compressed state when the supply path is blocked may not match the amount of push-back L1 (see Figure 8A) when the administration of the medicinal solution is complete, depending on the viscosity of the medicinal solution used and the material of gasket 131. In such a case, the amount of push-back due to the increase in thickness of gasket 131 from a compressed state to a non-compressed state when the supply path is blocked may be set separately, and the sum of the amount of push-back L3 and the separately set amount of push-back may be set as amount of push-back L2.

[0104] The above describes the drug solution administration device of the present invention through embodiments, but the present invention is not limited to the described configurations and can be modified as appropriate based on the description of the claims.

[0105] This application is based on Japanese Patent Application No. 2020-54542 filed on March 25, 2020, the disclosure of which is incorporated by reference in its entirety. [Explanation of symbols]

[0106] 10 Drug delivery system; 100 Drug administration device, 110 Liquid medicine containers, 110a: an inner wall of a drug solution container; 110b: an inner wall of the tip side of the drug solution container; 130 Pusher, 131 Gasket, 140 Drive mechanism, 141 motor, 144 Rotation detector, 144a Photointerrupter, 144b Slit plate, 150 control section, A threshold (upper current limit), A1, B1 Motor current value, H body surface, L Return amount, L1, L2, L3 push back amount, T1, T2 times.

Claims

1. A liquid medicine container filled with a liquid medicine; A pusher for pushing out the liquid medicine in the liquid medicine container; a gasket disposed at a tip of the plunger, slidable against an inner wall of the drug solution container and separated from the plunger; a drive mechanism for moving the plunger back and forth relative to the tip opening of the drug solution container; A control unit for controlling the operation of the drive mechanism, The tip of the pusher pushes the gasket to push out the liquid medicine in the liquid medicine container, The pusher separates from the gasket and retreats, When the gasket is released from the pressure applied by the plunger, an increase in the thickness of the gasket caused by the gasket returning from a compressed state to a non-compressed state is defined as a push-back amount L1, an amount of movement of the gasket caused by an increased pressure applied to the chemical solution remaining in the chemical solution container and the supply path is defined as a push-back amount L3, and a total amount of the push-back amount L1 and the push-back amount L3 is defined as a push-back amount L2. the drive mechanism includes a motor that generates a drive force for moving the plunger forward and backward, and a rotation detection unit that detects rotation of the motor; the control unit has an operation confirmation function for confirming an operation status of the motor based on a detection result of the rotation detection unit, The control unit is After confirming that the motor has stopped by the operation confirmation function, the motor is started to rotate in reverse to determine whether the plunger moves backward. If the motor does not rotate in reverse, it is determined that an administration error has occurred. When the motor rotates in the reverse direction, the motor is rotated in the reverse direction to move the plunger backward by a return amount L, which is a distance by which the plunger is moved from the current position toward the base end side, and then the motor is rotated in the forward direction to determine whether or not the plunger has struck the gasket based on the value of the current flowing through the motor or the rotational speed of the motor. If the plunger hits the gasket, it is determined that a blockage has occurred; If the plunger does not hit the gasket, it is determined that the administration of the medicinal liquid in the medicinal liquid container has been completed; A medicinal solution administration device, wherein the return amount L is greater than the push-back amount L1 and smaller than the push-back amount L2.

2. The drug solution administration device according to claim 1 , wherein the control unit determines that the motor has failed when the plunger does not move backward even when the motor is started to rotate in reverse.

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