Inflation / deflation device and method for operating same

Abstract

This inflation / deflation device, to which a catheter having a balloon at a distal part can be connected, comprises: a pump for injecting a fluid into the catheter; a negative pressure source for applying negative pressure to the catheter; a first switching valve having a first port connected to the pump via a first flow passage, a second port connected to the negative pressure source via a second flow passage, and a third port to which the catheter can be connected; and a control unit for controlling the operation of the inflation / deflation device. The first switching valve can switch a flow passage, communicating with the catheter connected to the third port, between the first flow passage connected to the first port and the second flow passage connected to the second port.

Description

Indeflation device and method of operation thereof

[0001] The present disclosure relates to an indeflation device and its method of operation.

[0002] When using a balloon catheter or a stent delivery system equipped with a balloon catheter, it is necessary to remove the air from the catheter and replace it with a fluid such as a contrast agent as a preparatory step before expanding the balloon. This preparatory step aims to ensure contrast during balloon expansion and to reduce the risk of air leaking if the balloon breaks inside the blood vessel.

[0003] It is known to perform such priming manually, for example by using a fluid-filled angioplasty balloon pressurizer or a syringe filled with a small amount of fluid to manually remove air from the balloon catheter, and then manually operating the pressurizer piston to inflate and deflate the balloon.

[0004] There are also known devices that automatically perform the preparation work for a balloon catheter. For example, Patent Document 1 describes a device that draws fluid from a reservoir into a pressurizing unit, removes air from a balloon catheter, and injects fluid from the pressurizing unit into the balloon to expand the balloon.

[0005] U.S. Patent No. 8,758,294

[0006] However, the conventional configuration leaves room for improvement in terms of more efficiently carrying out the preparation work for the balloon catheter.

[0007] An object of the present disclosure is to enable the preparation of a balloon catheter to be performed more efficiently.

[0008] According to the present disclosure, the inflation device comprises: (1) an inflation device capable of connecting a catheter having a balloon at its distal end, comprising: a pump for injecting fluid into the catheter; a negative pressure source for applying negative pressure to the catheter; a first switching valve having a first port connected to the pump via a first flow path, a second port connected to the negative pressure source via a second flow path, and a third port to which the catheter can be connected; and a control unit for controlling the operation of the inflation device, wherein the first switching valve is capable of switching the flow path communicating with the catheter connected to the third port between the first flow path connected to the first port and the second flow path connected to the second port.

[0009] (2) In the inflation device of (1), the control unit may: cause the pump to fill the first flow path with the fluid; cause the negative pressure source to suck air from the catheter when the catheter is connected to the third port of the first switching valve and the catheter and the second flow path are connected by the first switching valve; and cause the pump to fill the catheter with the fluid when the catheter and the first flow path are connected by the first switching valve.

[0010] (3) In the inflation device of (1) or (2), the pump may include: a syringe capable of storing the fluid, the syringe having a first opening communicating with the first flow path and a second opening for receiving a supply of the fluid from a reservoir that stores the fluid; a plunger provided within the syringe and movable in the longitudinal direction of the syringe; and a drive unit that moves the plunger within a movable range.

[0011] (4) In the indeflation device of (3), the syringe may have the first opening lower than the second opening.

[0012] (5) In the inflation device of (3) or (4), a second switching valve is further provided having a fourth port connected to the second opening of the syringe, a fifth port to which the reservoir can be connected, and a sixth port connected to an air vent, and the second switching valve may be capable of switching the flow path within the second switching valve so that any two of the second opening connected to the fourth port, the reservoir connected to the fifth port, and the air vent connected to the sixth port are connected to each other.

[0013] (6) In the inflation device of (5), a filter that allows air to pass through but does not allow the fluid to pass through may be provided at the vent.

[0014] (7) In the indeflation device of (5) or (6), the syringe may have the second opening at the top of the inner wall of the syringe.

[0015] (8) In any of the inflation devices (5) to (7), the control unit may, when the second opening of the syringe and the reservoir are connected by the second switching valve, cause the drive unit to pull the plunger to move the fluid from the reservoir into the syringe; when the second opening of the syringe and the air vent are connected by the second switching valve, cause the drive unit to push the plunger to discharge air from the syringe; and when the reservoir and the air vent are connected by the second switching valve, cause the drive unit to push the plunger to fill the first flow path with the fluid.

[0016] (9) In the indeflation device according to any one of (5) to (8), a force sensor for detecting the pressure inside the syringe may be further provided.

[0017] (10) In the indeflation device of (9), the force sensor may be provided on the plunger.

[0018] (11) In the inflation device of (9) or (10), the control unit may: when the second opening of the syringe and the reservoir are connected by the second switching valve, cause the drive unit to pull the plunger; when the second opening of the syringe and the air vent are connected by the second switching valve, cause the drive unit to push the plunger until the pressure inside the syringe reaches a predetermined value; and when the reservoir and the air vent are connected by the second switching valve, cause the drive unit to push the plunger.

[0019] (12) In the inflation device according to any one of (3) to (11), a third switching valve may be further provided for switching between opening and closing the first flow path.

[0020] (13) In any of the inflation devices (1) to (11), the third port of the first switching valve may be connectable to the catheter via a third flow path having a connection portion at a distal portion, and the first switching valve may be capable of switching the flow path communicating with the catheter connected to the third port via the third flow path between the first flow path connected to the first port and the second flow path connected to the second port.

[0021] (14) In the inflation device according to any one of (1) to (13), an air bubble sensor may be further provided to detect air bubbles in the first flow path.

[0022] According to the present disclosure, a method for operating an inflation device is (15) a method for operating an inflation device comprising: a syringe pump for injecting a fluid into a catheter having a balloon at its distal end; a negative pressure source for applying negative pressure to the catheter; a first switching valve having a first port connected to the pump via a first flow path, a second port connected to the negative pressure source via a second flow path, and a third port to which the catheter can be connected; and a control unit, wherein the control unit causes the pump to perform an operation of filling the first flow path with the fluid; causes the negative pressure source to perform an operation of sucking air from the catheter when the catheter is connected to the third port of the first switching valve and the catheter and the two flow paths are connected by the first switching valve; and causes the pump to perform an operation of filling the catheter with the fluid when the catheter and the first flow path are connected by the first switching valve.

[0023] (16) In the method for operating the inflation device of (15), the pump is a syringe pump including: a syringe capable of storing the fluid, the syringe having a first opening communicating with the first flow path and a second opening for receiving a supply of the fluid from a reservoir that stores the fluid; a plunger provided in the syringe and movable in the longitudinal direction of the syringe; and a drive unit that moves the plunger within a movable range; and the inflation device further includes a second switching valve having a fourth port connected to the second opening of the syringe, a fifth port to which the reservoir can be connected, and a sixth port connected to an air vent, and the control unit causes the drive unit to pull the plunger when the second opening of the syringe and the reservoir are in communication with each other through the second switching valve, thereby moving the fluid from the reservoir into the syringe; The method may include causing the drive unit to press the plunger to discharge air from the syringe when the second opening of the syringe and the vent port are in communication with each other via the second selector valve; causing the drive unit to press the plunger to fill the first flow path with the fluid when the reservoir and the vent port are in communication with each other via the second selector valve; causing the negative pressure source to suck air from the catheter when the catheter is connected to the third port of the first selector valve and the catheter and the second flow path are in communication with each other via the first selector valve; and causing the drive unit to press the plunger to fill the catheter with the fluid when the catheter and the first flow path are in communication with each other via the first selector valve.

[0024] According to one embodiment of the present disclosure, preparation work for a balloon catheter can be performed more efficiently.

[0025] FIG. 1 is a schematic diagram showing an example of the configuration of an indeflation device according to one embodiment. FIG. 2 is a flowchart showing an example of the operation of the indeflation device of FIG. 1. FIG. 3 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 4 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 5 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 6 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 7 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 8 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 9 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 10 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 11 is a diagram explaining an example of the operation of the indeflation device of FIG. 1. FIG. 12 is a diagram explaining an example of the operation of the indeflation device of FIG. 1.

[0026] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, parts having the same configuration or function are denoted by the same reference numerals. In the description of this embodiment, duplicated descriptions of the same parts may be omitted or simplified as appropriate.

[0027] (Outline of inflation device 1) Fig. 1 is a schematic diagram showing an example of the configuration of an inflation device 1 according to one embodiment. The inflation device 1 pressurizes or depressurizes the inside of the balloon catheter 50 by moving a fluid within the balloon catheter 50. The fluid injected into the balloon catheter 50 is, for example, a contrast agent, but may alternatively be any liquid or gas, such as saline, that is harmless when injected into the body.

[0028] A balloon catheter 50 as a catheter according to this embodiment has a configuration in which a balloon 51 that expands or contracts in response to internal pressure is attached to the distal portion of a hollow tube 52. The balloon catheter 50 is inserted into the patient's body. The balloon catheter 50 can be connected to a first switching unit 40 (described below) via a hub 53. After the balloon 51 is positioned at the target position, the inflation device 1 expands or contracts the balloon 51 by pressurizing or depressurizing the balloon catheter 50. The balloon catheter 50 may be a disposable item that is discarded after a single use. In this embodiment, the inflation device 1 expands or contracts the balloon catheter 50 having the balloon 51 attached to its distal portion, but the inflation device 1 may also process catheters other than the balloon catheter 50.

[0029] Hereinafter, the person who uses the inflation device 1 and the balloon catheter 50 will be collectively referred to as the "user." The user is, for example, a medical professional including a doctor, a nurse, and a clinical engineer, and multiple people may operate the device as users.

[0030] As shown in FIG. 1 , the inflation device 1 includes a control device 10 , a pump 20 , a negative pressure source 30 , and a first switching valve 40 .

[0031] The control device 10 is a computer that controls the overall operation of the inflation device 1. In this embodiment, the control device 10 is communicatively connected to the actuators 23, 33, the first switching valve 40, the second switching valve 26, and the third switching valve 66, and controls the operation of these components. However, some or all of the first switching valve 40, the second switching valve 26, and the third switching valve 66 may be manually switched by the user.

[0032] The pump 20 operates to inject a fluid into the balloon catheter 50. The pump 20 is connected to the first switching valve 40 via a first flow path 61.

[0033] The negative pressure source 30 operates to apply negative pressure to the balloon catheter 50. The negative pressure source 30 is connected to the first switching valve 40 via the second flow path 62. The first flow path 61 and the second flow path 62 may be formed, for example, by flexible resin tubes.

[0034] The first switching valve 40 has a first port 41 connected to the pump 20 via a first flow path 61, a second port 42 connected to the negative pressure source 30 via a second flow path 62, and a third port 40 to which the hub 53 of the balloon catheter 50 can be connected.

[0035] In this configuration, the first switching valve 40 can switch the flow path communicating with the balloon catheter 50 connected to the third port 43 between the first flow path 61 connected to the first port 41 and the second flow path 62 connected to the second port 42. Therefore, the inflation device 1 can efficiently remove air from the balloon catheter 50 by applying negative pressure from the negative pressure source 30 while the balloon catheter 50 is connected to the second flow path 62 by the first switching valve 40, thereby isolating the first flow path 61. The inflation device 1 can prevent fluid from moving to the negative pressure source 30 by isolating the first flow path 61 for injecting fluid from the second flow path 62 for applying negative pressure by the first switching valve 40. The control device 10 controls the operation of the inflation device 1, automatically performing a series of preparatory steps, from removing air from the balloon catheter 50 to injecting fluid. Therefore, the inflation device 1 can more efficiently perform the preparatory steps for the balloon catheter 50.

[0036] (Control device 10) The control device 10 may be, for example, any electronic device having general-purpose functionality, such as an FPGA (Field Programmable Gate Array) or a PC (Personal Computer), or any electronic device for a specific purpose, such as an embedded device. As shown in Fig. 1 , the control device 10 includes a control unit 11, a storage unit 12, a communication unit 13, an input unit 14, and an output unit 15.

[0037] The control unit 11 includes one or more processors. In one embodiment, the "processor" may be, but is not limited to, a general-purpose processor or a dedicated processor specialized for a specific process. The control unit 11 is communicably connected to each component of the control device 10 and controls the operation of the entire control device 10.

[0038] The storage unit 12 includes any storage module, such as a hard disk drive (HDD), a solid state drive (SSD), a read-only memory (ROM), and a random access memory (RAM). The storage unit 12 may function as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 12 stores any information used in the operation of the control device 10. For example, the storage unit 12 may store system programs, application programs, and various information received by the communication unit 13. The storage unit 12 is not limited to being a device built into the control device 10, but may also be an external database or an external storage module.

[0039] The communication unit 13 includes any communication module that can communicate with other devices such as a medical management system using any communication technology. The communication unit 13 may further include a communication control module for controlling communication with other devices and a storage module for storing communication data such as identification information required for communication with other devices.

[0040] The input unit 14 includes one or more input interfaces that accept input operations from a user and acquire input information based on the user operations. For example, the input unit 14 may be, but is not limited to, physical keys, capacitive keys, a pointing device, a touch screen integrated with the display of the output unit 15, a microphone that accepts voice input, etc. The input unit 14 may be provided as, for example, a handheld controller that is communicatively connected to the control device 10.

[0041] The output unit 15 includes one or more output interfaces that output information to the user and notify the user. For example, the output unit 15 may be, but is not limited to, a display that outputs information as an image and a speaker that outputs information as sound. Such a display may be, for example, a liquid crystal panel display or an organic EL (Electro Luminescence) display. At least one of the input unit 14 and the output unit 15 may be configured integrally with the control device 10 or may be provided separately.

[0042] The functions of the control device 10 can be realized by executing a computer program (program) according to this embodiment on a processor included in the control unit 11. That is, the functions of the control device 10 can be realized by software. The computer program causes a computer to execute the processing of steps included in the operation of the control device 10, thereby causing the computer to realize the functions corresponding to the processing of each step. That is, the computer program is a program for causing a computer to function as the control device 10 according to this embodiment. The computer program may be recorded on a computer-readable recording medium. The program includes information used for processing by an electronic computer and information equivalent to a program. For example, data that is not a direct instruction to a computer but has properties that define computer processing falls under the category of "information equivalent to a program."

[0043] Some or all of the functions of the control device 10 may be realized by a dedicated circuit included in the control unit 11. That is, some or all of the functions of the control device 10 may be realized by hardware. Furthermore, the control device 10 may be realized by a single computer or by multiple computers working together.

[0044] 1, the pump 20 includes a syringe 21, a plunger 22, and an actuator 23. In this embodiment, the pump 20 is a syringe pump that delivers fluid filled in the syringe 21 into the balloon catheter 50 by the pressing action of the plunger 22, but the pump 20 may be a pump based on any principle. For example, the pump 20 may be a roller pump (peristaltic pump) or the like.

[0045] The syringe 21 can store the fluid to be delivered into the balloon catheter 50. The syringe 21 has a first opening 211 communicating with the first flow path 61 and a second opening 212 for receiving a supply of fluid from a reservoir 24 that stores the fluid. The plunger 22 is provided in the syringe 21 and is movable in the longitudinal direction of the syringe 21. The actuator 23 serving as a drive unit provides a driving force for moving the plunger 22 within the movable range. For example, the actuator 23 may apply a load to the plunger 22 using the driving force of a driver such as a motor, thereby moving the plunger 22 in the longitudinal direction of the syringe 21. The actuator 23 is driven under the control of the control unit 11 of the control device 10.

[0046] The second opening 212 of the syringe 21 is connected to the second switching valve 26. The second switching valve 26 has a fourth port 261 connected to the second opening 212 of the syringe 21, a fifth port 262 to which the reservoir 24 can be connected, and a sixth port 263 connected to the vent port 251. The second switching valve 26 can switch the flow path within the second switching valve 26 so that any two of the second opening 212 connected to the fourth port 261, the reservoir 24 connected to the fifth port 262, and the vent port 251 connected to the sixth port 263 communicate with each other.

[0047] In this way, by configuring the pump 20 as a syringe pump connected to the reservoir 24, fluid can be stored in the reservoir 24 and the pump 20 can be used repeatedly. The syringe 21 may have a first opening 211 for supplying fluid to the balloon catheter 50, which is located lower than the second opening 212. This configuration prevents air bubbles from being mixed into the fluid supplied to the balloon catheter 50. The syringe 21 may have a second opening 212 at the top of the inner wall of the syringe 21. In this way, by providing the second opening 212 connected to the air vent 251 at the top of the inner wall of the syringe 21, the inflation device 1 can collect air bubbles mixed into the fluid in the syringe 21 at the second opening 212 and effectively discharge them.

[0048] The second opening 212 of the syringe 21 can be connected to either the reservoir 24 or the vent port 251 via the second switching valve 26. Therefore, the inflation device 1 can move fluid from the reservoir 24 into the syringe 21 by pulling the plunger 22 while the second opening 212 of the syringe 21 is connected to the reservoir 24. The inflation device 1 can push air bubbles in the syringe 21 out through the vent port 251 by pushing the plunger 22 while the second opening 212 is connected to the vent port 251.

[0049] A filter 25 is provided in the vent 251. The filter 25 may be a hydrophobic filter selected from a material that allows air to pass through but not fluid. With this configuration, the inflation device 1 can fill the series of flow paths from the reservoir 24 to the syringe 21 with fluid while effectively discharging only air bubbles mixed in the fluid in the syringe 21 through the filter 25. Details of the operation of removing air bubbles from the syringe 21 through the vent 251 will be described later.

[0050] (First flow path 61) The first flow path 61 connects the first opening 211 of the syringe 21 and the first switching valve 40. The inflation device 1 may include a third switching valve 66 that switches between opening and closing the first flow path 61 that connects the syringe 21 and the first switching valve 40. As will be described later, the control device 10 controls the opening and closing of the third switching valve 66 and the operation of the plunger 22, thereby making it possible to appropriately fill the space between the syringe 21 and the first switching valve 40 with fluid.

[0051] The inflation device 1 may include an air bubble sensor 65 that detects air bubbles in the first flow path 61. For example, the air bubble sensor 65 may include a pair of a light emitter 651 and a light receiver 652. The light emitter 651 emits an imaging light beam having a specific wavelength toward the first flow path 61. The light beam emitted from the light emitter 651 passes through the first flow path 61, which is the subject, and forms an image on the light receiver 652. The light receiver 652 is a camera (two-dimensional sensor) that photoelectrically converts the light beam imaged on the light receiver 652 to form a captured image. The light receiver 652 may be configured, for example, with a complementary metal-oxide semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor. The air bubble sensor 65 may analyze the captured image to detect the presence or absence of air bubbles. Instead of such an optical sensor, the air bubble sensor 65 may be a sensor based on another method, such as an ultrasonic method. The ultrasonic bubble sensor 65 may detect bubbles in the first flow path 61 based on the fact that when bubbles are mixed into the first flow path 61, the propagation efficiency of the ultrasonic waves passing through the first flow path 61 decreases and the received strength becomes weaker.

[0052] By equipping the inflation device 1 with such a bubble sensor 65, upon detecting air bubbles mixed in with the fluid supplied to the balloon catheter 50, the inflation device 1 may output an alarm or the like using audio or images from the output unit 15, etc., stop the operation of the plunger 22 and wait for the user's decision, or pull the plunger 22 to prevent air bubbles from entering the balloon catheter 50, etc.

[0053] The inflation device 1 may include a force sensor 221 for detecting the pressure inside the syringe 21, for example, on the plunger 22. The control device 10 acquires the load detected by the force sensor 221 and detects the pressure inside the syringe 21. By including the force sensor 221, the inflation device 1 can control the opening and closing of the first switching valve 40 and the second switching valve 26, as well as the movement of the plunger 22, while maintaining the pressure of the fluid inside the syringe 21 at an appropriate value. Specifically, for example, by providing the force sensor 221 on the plunger 22, the inflation device 1 can determine the pressure inside the syringe 21 with high accuracy based on the load applied to the plunger 22. The force sensor 221 is, for example, a load cell, but may be implemented by any sensor. Details of operation control based on the measurement value of the force sensor 221 will be described later.

[0054] (Negative Pressure Source 30) The negative pressure source 30 includes a syringe 31, a plunger 32, and an actuator 33. In this embodiment, the negative pressure source 30 is a syringe pump that applies negative pressure to the second flow path 62 connected to the syringe 31 by pulling the plunger 22 inside the syringe 31, but the operating principle by which the negative pressure source 30 generates negative pressure is arbitrary. An example in which the negative pressure source 30 is configured as a vacuum pump will be described later with reference to FIG. 13 .

[0055] The syringe 31 has a third opening 311 that communicates with the second flow path 62. The plunger 32 is provided inside the syringe 31 and is movable in the longitudinal direction of the syringe 31. The actuator 33 provides a driving force for moving the plunger 32 within the movable range. The actuator 33 is driven based on the control of the control unit 11 of the control device 10. The actuator 33 pulls the plunger 32 from the syringe 31, thereby applying negative pressure to the second flow path 62. For example, the syringe 31, the plunger 32, and the actuator 33 may have the same configuration as the syringe 21, the plunger 22, and the actuator 23 of the pump 20.

[0056] (Example of Operation of Indeflation Device 1) An example of operation of the inflation device 1 described with reference to Figure 1 will be described with reference to Figures 1 to 12. Figure 2 is a flowchart showing an example of operation of the inflation device 1 of Figure 1. The operation of the inflation device 1 described with reference to Figure 2 may correspond to one of the operating methods of the inflation device 1. The operation of each step in Figure 2 may be executed based on control by the control unit 11 of the control device 10. Figures 3 to 12 are diagrams explaining an example of operation of the inflation device 1 of Figure 1. Of the components of the inflation device 1, the control device 10 is not shown in Figures 3 to 12.

[0057] In the initial state, the plunger 22 of the pump 20 is inserted all the way into the syringe 21. The plunger 32 of the negative pressure source 30 is inserted all the way into the syringe 31. The balloon catheter 50 is not connected to the first switching valve 40. The first switching valve 40 is in a state where the third port 43 and the first port 41 are in communication. The reservoir 24 in which the fluid L is stored is connected to the fifth port 262 of the second switching valve 26. The second switching valve 26 is in a state where the fourth port 261 and the sixth port 263 are in communication. The third switching valve 66 of the first flow path 61 is closed. In this initial state, the control unit 11 executes the following processing.

[0058] 2 , the control unit 11 moves the fluid L from the reservoir 24 into the syringe 21. Specifically, the control unit 11 controls the second switching valve 26 to connect the second opening 212 of the syringe 21 to the reservoir 24. Thereafter, the control unit 11 causes the actuator 23 to pull the plunger 22, thereby moving the fluid L from the reservoir 24 into the syringe 21.

[0059] 3 shows the state in which fluid L is transferred from reservoir 24 to syringe 21. In FIG. 3, closed ports are indicated by black triangles, and open ports are indicated by white triangles. For example, in first selector valve 40, first port 41 and third port 43 are open and communicate with each other, while second port 42 is closed. In second selector valve 26, sixth port 263 is closed, and fourth port 261 and fifth port 262 are communicated with each other. Third selector valve 66 is closed.

[0060] When the actuator 23 pulls the plunger 22 in this state, the negative pressure causes the fluid L in the reservoir 24 to move to the syringe 21 via the second switching valve 26. In the example of Figure 3, air A is mixed into the fluid L in the syringe 21.

[0061] Therefore, in step S2 of Fig. 2, control unit 11 discharges air A from syringe 21. Specifically, control unit 11 controls second switching valve 26 to connect fourth port 261 and sixth port 263, and then causes actuator 23 to press plunger 22. As described above, second opening 212 is provided at the top of the inner wall of syringe 21, and therefore air A collects near second opening 212 on the second switching valve 26 side. When pressure is applied by the pressing action of plunger 22 in this state, air A is discharged to the outside through vent 251 (Fig. 4).

[0062] As described above, the vent 251 is provided with a hydrophobic filter 25. Therefore, when all of the air A in the syringe 21 is removed through the vent 251, the fluid L cannot pass through the filter 25, and the pressure in the syringe 21 increases. Therefore, the control unit 11 controls the actuator 23 to press the plunger 22 until the pressure in the syringe 21 reaches a predetermined value. The control unit 11 acquires a measurement value of the load on the plunger 22 using the force sensor 221 and converts the measurement value into a pressure in the syringe 21, thereby obtaining the pressure in the syringe 21. When the pressure in the syringe 21 reaches the predetermined value, the control unit 11 controls the second switching valve 26 to connect the fifth port 262 and the sixth port 263 and close the second opening 212 of the syringe 21 ( FIG. 5 ).

[0063] In step S3 of FIG. 2 , the control unit 11 fills the first flow path 61 with the fluid L. Specifically, the control unit 11 opens the third switching valve 66 and then causes the actuator 23 to press the plunger 22. As the actuator 23 continues to press the plunger 22, the first flow path 61 is filled with the fluid L from the syringe 21 side. Concurrently, air originally present in the first flow path 61 is discharged to the outside through the third port 43 of the first switching valve 40. FIG. 6 shows the first flow path 61 filled with the fluid L. If the air bubble sensor 65 detects air bubbles during the process of filling the first flow path 61 with the fluid L, the control unit 11 may output an alarm, such as an audio or visual alarm, from the output unit 15. This allows the user to notice the presence of air bubbles and take necessary measures to remove the bubbles.

[0064] In the example of FIG. 6 , since the fluid L has reached the position of the first switching valve 40, if the actuator 23 further presses the plunger 22, the fluid L will flow out through the opening of the third port 43. Therefore, the control device 10 may store in advance in the memory unit 12 the amount of movement of the plunger 22 required for the fluid L to reach the first switching valve 40 after the third switching valve 66 is opened. This amount of movement may be represented by any equivalent value, such as the number of rotations of a component constituting the actuator 23 or the length of movement of the plunger 22. After opening the third switching valve 66, the control unit 11 may move the plunger 22 by the amount of movement previously stored in the memory unit 12 and then stop the plunger 22. This prevents the fluid L from leaking from the third port 43 of the first switching valve 40.

[0065] When the first flow path 61 is filled with the fluid L, the user connects the hub 53 of the balloon catheter 50 to the third port 43 of the first switching valve 40. Figure 7 shows the balloon catheter 50 attached to the first switching valve 40.

[0066] In step S4 of Fig. 2, the control unit 11 aspirates air from the balloon catheter 50. Specifically, the control unit 11 controls the first switching valve 40 to connect the third port 43 and the second port 42. This connects the balloon catheter 50 to the syringe 31 of the negative pressure source 30 via the second flow path 62. The control unit 11 then causes the actuator 33 to pull the plunger 32, applying negative pressure to the balloon catheter 50 and reducing the pressure inside the balloon catheter 50. Fig. 8 shows the process of reducing the pressure inside the balloon catheter 50.

[0067] After causing the actuator 33 to pull the plunger 32 as far as possible within the movable range, the control unit 11 stops the decompression after a certain time (e.g., several seconds) has elapsed, and proceeds to step S5. The control unit 11 may stop the decompression when the pressure in the balloon catheter 50 and the pressure in the syringe 31 have reached equilibrium, and proceeds to step S5. The control unit 11 may determine the timing to stop the decompression based on, for example, a measurement value of a pressure gauge provided in the syringe 31 or a pressure conversion value in the syringe 31 obtained based on a measurement value of a force sensor, such as a compression-tension type load cell, attached to the plunger 32.

[0068] In step S5 of FIG. 2 , the control unit 11 fills the balloon catheter 50 with fluid L. Specifically, the control unit 11 controls the first switching valve 40 to connect the third port 43 to the first port 41. This connects the balloon catheter 50 to the syringe 21 of the pump 20 via the first flow path 61, and the fluid L flows into the balloon catheter 50 from the first flow path 61 due to the pressure difference between the first flow path 61 and the balloon catheter 50. As a result, the air in the balloon catheter 50 is replaced with the fluid L. For example, the control unit 11 may pump the fluid L within a range that maintains a negative pressure inside the syringe 21 so as to prevent the balloon catheter 50 from inflating. FIG. 9 shows the balloon catheter 50 in which the air inside has been replaced with the fluid L. The balloon 51 filled with the fluid L has a diameter large enough to be inserted into a body cavity such as a patient's blood vessel.

[0069] The user inserts the balloon catheter 50, the air inside which has been replaced with the fluid L, into a body cavity such as a blood vessel of the patient, and causes the balloon 51 to reach a target position such as a lesion. For example, the user may align the balloon 51 while checking an image of the lesion taken by an X-ray camera on a monitor. Once the user confirms that the balloon 51 has reached the target position, the user operates the input unit 14 to set a desired pressure and instructs the inflation device 1 to apply pressure.

[0070] When a medical device such as a stent is mounted on the balloon catheter 50, the control unit 11 performs the processing of steps S4 and S5 after the user inserts the balloon catheter 50 into a body cavity such as a blood vessel of the patient and aligns it.

[0071] 2, the control unit 11 determines whether or not a command to apply pressure has been received from the user. If the command to apply pressure has been received (YES in step S6), the control unit 11 proceeds to step S7, and if not (NO in step S6), the control unit 11 waits.

[0072] In S7, the control unit 11 pressurizes the balloon catheter 50. Specifically, the control unit 11 causes the actuator 23 to push the plunger 22 until the pressure inside the syringe 21, measured using the force sensor 221, reaches the pressure set by the user. This increases the internal pressure of the balloon catheter 50, causing the balloon 51 to expand within the body cavity. FIG. 10 shows the balloon catheter 50 being pressurized with fluid L. The user utilizes the expanding action of the balloon 51 to perform a desired treatment, such as dilating a stenotic portion in a coronary artery lesion or placing or crimping a stent. After completing the required treatment, the user operates the input unit 14 to instruct the inflation device 1 to depressurize.

[0073] 2, the control unit 11 determines whether or not a pressure reduction instruction has been received from the user. If a pressure reduction instruction has been received (YES in step S8), the control unit 11 proceeds to step S9, and if not (NO in step S8), the control unit 11 waits.

[0074] In step S9, the control unit 11 depressurizes the balloon catheter 50. Specifically, the control unit 11 causes the actuator 23 to pull the plunger 22 until the pressure inside the syringe 21, measured using the force sensor 221, becomes equal to or less than atmospheric pressure. This reduces the internal pressure of the balloon catheter 50, causing the balloon 51 to contract within the body cavity. FIG. 11 shows the process of depressurizing the balloon catheter 50. After depressurizing the balloon catheter 50, the user removes the balloon catheter 50 from the patient's body cavity. The user then removes the hub 53 of the balloon catheter 50 from the first switching valve 40 ( FIG. 12 ). After completing the process of step S9, the control unit 11 ends the process of the flowchart.

[0075] After step S9 is completed, if a treatment is to be performed on another patient, the user may attach the balloon catheter 50 to be used on that patient to the first switching valve 40. In this case, the user confirms that the first flow path 61 is filled with the fluid L, and if so, the control unit 11 resumes the process from step S4. If a portion of the first flow path 61 is not filled with the fluid L, the control unit 11 resumes the process from step S3.

[0076] As described above, the inflation device 1 can be connected to a balloon catheter 50 having a balloon 51 at its distal end. The inflation device 1 includes a pump 20, a negative pressure source 30, a first switching valve 40, and a control unit 11. The pump 20 operates to inject a fluid L into the balloon catheter 50. The negative pressure source 30 operates to apply negative pressure to the balloon catheter 50. The first switching valve 40 has a first port 41 connected to the pump 20 via a first flow path 61, a second port 42 connected to the negative pressure source 30 via a second flow path 62, and a third port 43 to which the balloon catheter 50 can be connected. The first switching valve 40 can switch the flow path communicating with the balloon catheter 50 connected to the third port 43 between a first flow path 61 connected to the first port 41 and a second flow path 62 connected to the second port 42.

[0077] In this configuration, the control unit 11 causes the pump 20 to fill the first flow path 61 with the fluid L. With the balloon catheter 50 connected to the third port 43 of the first switching valve 40 and the balloon catheter 50 and the second flow path 62 in communication with each other via the first switching valve 40, the control unit 11 causes the negative pressure source 30 to suck air out of the balloon catheter 50. With the balloon catheter 50 and the first flow path 61 in communication with each other via the first switching valve 40, the control unit 11 causes the pump 20 to fill the balloon catheter 50 with the fluid L.

[0078] As described above, in this embodiment, the control unit 11 controls the operation of filling the first flow path 61 with the fluid L, the operation of aspirating air from the balloon catheter 50, and the operation of filling the balloon catheter 50 with the fluid L. Therefore, the inflation device 1 can automatically perform preparatory operations from removing air from the balloon catheter 50 to injecting the fluid L. Furthermore, because the pump 20 that injects the fluid L and the negative pressure source 30 that applies negative pressure are switchably connected to the balloon catheter 50 by the first switching valve 40, the inflation device 1 can automate the removal of air from the balloon catheter 50 and replacement with a contrast agent by switching the flow path. Furthermore, the pump 20 is configured as a syringe pump, and the syringe 21 is connected not only to the first switching valve 40 via the first opening 211 but also to the reservoir 24 filled with the fluid L and the vent port 251 via the second opening 212. Therefore, by controlling the movement of the second switching valve 26, the third switching valve 66, and the plunger 22, the inflation device 1 can automatically fill the syringe 21 with the fluid L and remove the air A from the syringe 21. After filling the syringe 21 with the fluid L, the inflation device 1 can automatically fill the first flow path 61 with the fluid L by opening the third switching valve 66 and pressing the plunger 22.

[0079] Furthermore, in this embodiment, the inflation device 1 uses separate first and second flow paths 61 and 62 to introduce the fluid L into the balloon catheter 50 and exhaust the fluid from the balloon catheter 50. Therefore, the inflation device 1 can reduce the risk of the fluid L being dispersed into the air during exhaust, which could cause an infection or cause the negative pressure source 30 to malfunction.

[0080] In this embodiment, the inflation device 1 switches the first switching valve 40, the second switching valve 26, and the third switching valve 65 under the control of the control unit 11, but at least one of these valves may be switched manually by the user.

[0081] Furthermore, while FIG. 1 shows an example in which the negative pressure source 30 is configured as a syringe pump, the negative pressure source 30 may be configured as another device. An example in which the negative pressure source is configured as another device will be described with reference to FIG. 13. FIG. 13 is a schematic diagram showing an example configuration of an inflation apparatus 1 according to another embodiment. In FIG. 13, the negative pressure source 35 is configured as a vacuum pump 38. In FIG. 13, components common to FIG. 1 are assigned the same reference numerals, and detailed description will be omitted. In FIG. 13, the control device 10 is omitted. In FIG. 13, the inflation apparatus 1 includes a liquid receiver 36, a filter 37, and a vacuum pump 38 as the negative pressure source 35.

[0082] The liquid receiver 36 is a trap provided before the vacuum pump 38 when viewed from the first switching valve 40. The liquid receiver 36 has the function of storing the fluid L when the fluid L remaining in the balloon catheter 50, the first switching valve 40, the second flow path 62, etc. is drawn in by the negative pressure action of the vacuum pump 38. This makes it possible to reduce the risk of the fluid L flowing into the vacuum pump 38 and causing the vacuum pump 38 to break down.

[0083] The filter 37 has a function of allowing air to pass through but not allowing pathogens to pass through. When the negative pressure of the vacuum pump 38 draws in the fluid L remaining in the first switching valve 40 or the second flow path 62, the filter 37 prevents the fluid L from contaminating the vacuum pump 38 and being dispersed into the air via the vacuum pump 38, causing an infection or the like.

[0084] The vacuum pump 38 is a pump that applies negative pressure to the balloon catheter 50. The vacuum pump 38 is, for example, a diaphragm pump, but may be any other type of pump. For example, the vacuum pump 38 may be a rocking piston pump, a rotary vane pump, a scroll pump, a multi-stage Roots pump, or an oil rotary pump.

[0085] The control unit 11 of the control device 10 may control the operation of the negative pressure source 35 (vacuum pump 38) in the same manner as the negative pressure source 30 in Fig. 1. For example, the control unit 11 may control the operation of steps S1 to S3 and S5 to S9 in Fig. 2 as described above, and in step S4, air may be sucked from the balloon catheter 50 by the negative pressure source 35 instead of the negative pressure source 30.

[0086] Regardless of which pump is used as the negative pressure source 30, the control unit 11 aspirates the air from the balloon catheter 50 in step S4 of Fig. 2, and then switches the first switching valve 40 in step S5 to connect the balloon catheter 50 to the pump 20. Here, since it is desirable to minimize the presence of air within the balloon catheter 50, it is desirable for the negative pressure source 30 to be as powerful as possible. For example, when the negative pressure source 30 is realized by a syringe pump, it is desirable to increase the capacity of the syringe 31 and reduce the length and inner diameter of the second flow path 62 to a range that does not interfere with user operation, thereby reducing the volume of the second flow path 62.

[0087] Furthermore, while the inflation device 1 in Figures 1 and 13 is used by directly attaching the hub 53 of the balloon catheter 50 to the third port 43 of the first switching valve 40, this configuration is not limited to this. An example in which the first switching valve 40 and the balloon catheter 50 are connected via separate flow paths will be described with reference to Figure 14. Figure 14 is a schematic diagram showing an example configuration of the inflation device 1 according to one embodiment. In Figure 14, components common to those in Figure 1 are designated by the same reference numerals, and detailed description will be omitted. The control device 10 is omitted from Figure 14.

[0088] 14, a third flow path 68 having a connecting portion 69 at its distal end is attached to the third port 43 of the first switching valve 40. The third flow path 68 may be formed, for example, from a flexible resin tube. The connecting portion 69 can be attached to the hub 53 of the balloon catheter 50. Therefore, the third port 43 of the first switching valve 40 can be connected to the balloon catheter 50 via the third flow path 68. Unlike the configurations of FIGS. 1 and 13, the inflation device 1 of FIG. 14 does not have a third switching valve 66 that switches the first flow path 61 between open and closed.

[0089] The inflation apparatus 1 of Fig. 14 also operates according to the flowchart of Fig. 2. Below, an example of the operation of the inflation apparatus 1 of Fig. 14 will be described with reference to Fig. 2, focusing on the operations that differ from those of the inflation apparatus 1 of Fig. 1. The initial state before operation is basically the same as that of the inflation apparatus 1 of Fig. 1, but what differs from the case of Fig. 1 is that in the initial state of the configuration of Fig. 14, the first switching valve 40 is in a state in which the third port 43 and the second port 42 are in communication.

[0090] 2, the control unit 11 of the control device 10 moves the fluid L from the reservoir 24 into the syringe 21. In step S2, the control unit 11 discharges the air A from the syringe 21. The details of steps S1 and S2 are the same as those of the inflation device 1 in FIG.

[0091] In step S3, the control unit 11 fills the first flow path 61 with the fluid L. Specifically, the control unit 11 controls the first switching valve 40 to connect the third port 43 and the first port 41, and then causes the actuator 23 to press the plunger 22. As the actuator 23 continues to press the plunger 22, the first flow path 61 is filled with the fluid L from the syringe 21 side. Similar to the configuration of FIG. 1 , the control unit 11 may connect the third port 43 and the first port 41 of the first switching valve 40, move the plunger 22 by a movement amount pre-stored in the memory unit 12, and then stop the plunger 22. When the first flow path 61 from the syringe 21 to the first switching valve 40 is filled with the fluid L, the control unit 11 ends the process of moving the plunger 22.

[0092] Once the first flow path 61 is filled with the fluid L, the user connects the hub 53 of the balloon catheter 50 to the connection portion 69 of the third flow path 68, similar to the configuration of FIG.

[0093] In step S4, the control unit 11 aspirates air from the balloon catheter 50 and the third flow path 68. Specifically, similar to the configuration in FIG. 1 , the control unit 11 controls the first switching valve 40 to connect the third port 43 and the second port 42. Thereafter, the control unit 11 causes the actuator 33 to pull the plunger 32, applying negative pressure to the third flow path 68 and reducing the pressure in the balloon catheter 50 and the third flow path 68.

[0094] In step S5, the control unit 11 fills the balloon catheter 50 with fluid L. Specifically, similar to the configuration of FIG. 1 , the control unit 11 controls the first switching valve 40 to connect the third port 43 to the first port 41. As a result, the third flow path 68 is connected to the syringe 21 of the pump 20 via the first flow path 61, and the fluid L flows from the first flow path 61 into the balloon catheter 50 and the third flow path 68 due to the pressure difference between the first flow path 61 and the balloon catheter 50 and the third flow path 68. As a result, the air in the balloon catheter 50 is replaced with the fluid L. The control unit 11 may, for example, push the plunger 22 to deliver the fluid L within a range in which the pressure inside the syringe 21 is maintained at a negative pressure so as not to inflate the balloon catheter 50.

[0095] 1 , the user inserts the balloon catheter 50, the air inside which has been replaced with the fluid L, into a body cavity such as a blood vessel of a patient, and causes the balloon 51 to reach a target location such as a lesion. The user then instructs the inflation device 1 to pressurize.

[0096] In step S6, the control unit 11 waits until it receives an instruction to apply pressure from the user, and when it receives an instruction to apply pressure (YES in step S6), it proceeds to step S7.

[0097] In step S7, the control unit 11 pressurizes the balloon catheter 50. In step S8, the control unit 11 waits until it receives a command to depressurize from the user, and upon receiving the command to depressurize (YES in step S8), the process proceeds to step S9. In step S9, the control unit 11 depressurizes the balloon catheter 50. Upon completing the process of step S9, the control unit 11 ends the process of the flowchart. The details of steps S7 to S9 are the same as those of the inflation device 1 in FIG. 1.

[0098] 14 , the balloon catheter 50 is not directly attached to the first switching valve 40, but is connected to the first switching valve 40 via the third flow path 68. Therefore, in the configuration of FIG. 14 , the user only needs to attach the balloon catheter 50 to the connection portion 69 of the third flow path 68 at a position closer to the location where the treatment will be performed, improving the operability of the balloon catheter 50.

[0099] On the other hand, in the configuration of Figure 14, after step S9 is completed, fluid L remains in the third flow path 68. Therefore, if the balloon catheter 50 is replaced with another balloon catheter 50 for subsequent treatment, the fluid L remaining in the third flow path 68 must be aspirated when the balloon catheter 50 is evacuated. Furthermore, when the balloon catheter 50 is depressurized, the third flow path 68 must also be evacuated, increasing the volume of the area to be depressurized. As a result, even when the negative pressure source 30 performs an evacuating operation, air may remain in the balloon catheter 50. In contrast, in the configurations of Figures 1 and 13, even when the balloon catheter 50 is replaced with another balloon catheter 50 for subsequent treatment, the amount of fluid L to be aspirated is small, and the balloon catheter 50 can be evacuated more completely.

[0100] The present disclosure is not limited to the above-described embodiments. For example, multiple blocks shown in the block diagrams may be integrated, or one block may be divided. Multiple steps shown in the flowcharts may be executed in parallel or in a different order depending on the processing capabilities of the device executing each step, or as needed, instead of being executed in chronological order as described. Other modifications are possible without departing from the spirit of the present disclosure.

[0101] Furthermore, for example, the configuration and operation of the control device 10 may be distributed among multiple computers that can communicate with each other.

[0102] 1 Inflation device 10 Control device 11 Control unit 12 Memory unit 13 Communication unit 14 Input unit 15 Output unit 20 Pump 21 Syringe 211 First opening 212 Second opening 22 Plunger 221 Force sensor 23 Actuator 24 Reservoir 25 Filter 251 Vent 26 Second switching valve 261 Fourth port 262 Fifth port 263 Sixth port 30 Negative pressure source 31 Syringe 32 Plunger 321 Third opening 35 Negative pressure source 36 Liquid receiver 37 Filter 38 Vacuum pump 40 First switching valve 41 First port 42 Second port 43 Third port 50 Balloon catheter 51 Balloon 52 Tube 53 Hub 61 First flow path 62 Second flow path 65 Air bubble sensor 651 Light emitting part 652 Light receiving part 66 Third switching valve 68 Third flow path 69 Connection part

Claims

1. An inflation device to which a catheter having a balloon at its distal end can be connected, comprising: a pump for injecting fluid into the catheter; a negative pressure source for applying negative pressure to the catheter; a first switching valve having a first port connected to the pump via a first flow path, a second port connected to the negative pressure source via a second flow path, and a third port to which the catheter can be connected; and a control unit for controlling the operation of the inflation device, wherein the first switching valve is capable of switching the flow path communicating with the catheter connected to the third port between the first flow path connected to the first port and the second flow path connected to the second port.

2. The inflation device of claim 1, wherein the control unit: causes the pump to fill the first flow path with the fluid; causes the negative pressure source to suck air from the catheter when the catheter is connected to the third port of the first switching valve and the catheter and the two flow paths are connected by the first switching valve; and causes the pump to fill the catheter with the fluid when the catheter and the first flow path are connected by the first switching valve.

3. The inflation device of claim 1, wherein the pump comprises: a syringe capable of storing the fluid, the syringe having a first opening communicating with the first flow path and a second opening for receiving a supply of the fluid from a reservoir that stores the fluid; a plunger provided within the syringe and movable in the longitudinal direction of the syringe; and a drive unit that moves the plunger within a movable range.

4. The inflation device according to claim 3, wherein the syringe has the first opening lower than the second opening.

5. An inflation device as described in claim 3, further comprising a second switching valve having a fourth port connected to the second opening of the syringe, a fifth port to which the reservoir can be connected, and a sixth port connected to an air vent, wherein the second switching valve is capable of switching the flow path within the second switching valve so that any two of the second opening connected to the fourth port, the reservoir connected to the fifth port, and the air vent connected to the sixth port are connected to each other.

6. The inflation device of claim 5, wherein the vent is provided with a filter that allows air to pass through but does not allow the fluid to pass through.

7. The inflation device according to claim 5 or 6, wherein the syringe has the second opening at the top of the inner wall of the syringe.

8. The inflation device described in claim 5 or 6, wherein the control unit: when the second opening of the syringe and the reservoir are connected by the second switching valve, causes the drive unit to pull the plunger, thereby moving the fluid from the reservoir into the syringe; when the second opening of the syringe and the air vent are connected by the second switching valve, causes the drive unit to push the plunger, thereby discharging air from the syringe; and when the reservoir and the air vent are connected by the second switching valve, causes the drive unit to push the plunger, thereby filling the first flow path with the fluid.

9. The inflation device according to claim 5 or 6, further comprising a force sensor for detecting the pressure inside the syringe.

10. The inflation device according to claim 9, wherein the force sensor is provided on the plunger.

11. The inflation device described in claim 9, wherein the control unit: when the second opening of the syringe and the reservoir are connected by the second switching valve, causes the drive unit to pull the plunger; when the second opening of the syringe and the air vent are connected by the second switching valve, causes the drive unit to push the plunger until the pressure inside the syringe reaches a predetermined value; and when the reservoir and the air vent are connected by the second switching valve, causes the drive unit to push the plunger.

12. The inflation device according to claim 3, further comprising a third switching valve that switches between opening and closing the first flow path.

13. An inflation device as described in claim 1, wherein the third port of the first switching valve is connectable to the catheter via a third flow path having a connecting portion at its distal portion, and the first switching valve is capable of switching the flow path communicating with the catheter connected to the third port via the third flow path between the first flow path connected to the first port and the second flow path connected to the second port.

14. The inflation device of claim 1, further comprising an air bubble sensor for detecting air bubbles in the first flow path.

15. A method for operating an inflation device comprising: a syringe pump for injecting a fluid into a catheter having a balloon at its distal end; a negative pressure source for applying negative pressure to the catheter; a first switching valve having a first port connected to the pump via a first flow path, a second port connected to the negative pressure source via a second flow path, and a third port to which the catheter can be connected; and a control unit, wherein the control unit causes the pump to fill the first flow path with the fluid; causes the negative pressure source to suck air from the catheter when the catheter is connected to the third port of the first switching valve and the catheter and the second flow path are connected by the first switching valve; and causes the pump to fill the catheter with the fluid when the catheter and the first flow path are connected by the first switching valve.

16. The pump is a syringe pump comprising: a syringe capable of storing the fluid, the syringe having a first opening communicating with the first flow path and a second opening for receiving a supply of the fluid from a reservoir that stores the fluid; a plunger provided in the syringe and movable in the longitudinal direction of the syringe; and a drive unit that moves the plunger within a movable range; and the inflation device further comprises a second switching valve having a fourth port connected to the second opening of the syringe, a fifth port to which the reservoir can be connected, and a sixth port connected to an air vent; and the control unit causes the drive unit to pull the plunger when the second opening of the syringe and the reservoir are in communication with each other via the second switching valve, thereby moving the fluid from the reservoir into the syringe; 16. The method for operating an inflation device according to claim 15, comprising: causing the drive unit to press the plunger to discharge air from the syringe when the second opening of the syringe and the vent port are in communication with each other via the second switching valve; causing the drive unit to press the plunger to fill the first flow path with the fluid when the reservoir and the vent port are in communication with each other via the second switching valve; causing the negative pressure source to suck air from the catheter when the catheter is connected to the third port of the first switching valve and the catheter and the second flow path are in communication with each other via the first switching valve; and causing the drive unit to press the plunger to fill the catheter with the fluid when the catheter and the first flow path are in communication with each other via the first switching valve.

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