WO2008001881A1

WO2008001881A1 - Chemical liquid injection device

Info

Publication number: WO2008001881A1
Application number: PCT/JP2007/063082
Authority: WO
Inventors: Masahiro Sakakibara
Original assignee: Nemoto Kyorindo Co., Ltd.
Priority date: 2006-06-29
Filing date: 2007-06-29
Publication date: 2008-01-03
Also published as: JP5097705B2; JPWO2008001881A1

Abstract

A chemical liquid injection device has a piston pressing section (118) for holding a piston member of a chemical liquid syringe. The piston pressing section (118) has a flange holding member (123) for holding a flange of the piston member, a piston contact member (124), and a detection switch (130). The piston contact member (124) is projected so as to be in contact with the held piston member, and is provided so that it is displaced when the flange is held and so that, while the piston pressing section (118) presses the piston member, it is further displaced by force applied from the flange. Depending on displacement of the piston contact member (124), the detection switch (130) is switched between open and closed states about the time at which the flange is held and about the time at which force applied from the flange in chemical liquid injection reaches a predetermined level.

Description

Specification

Chemical injection device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a chemical solution injection device that injects a chemical solution from a chemical solution syringe filled with a chemical solution to a subject.

Background art

[0002] Medical diagnostic imaging devices include CT (Computed Tomography) scanner, MRI (Magnetic Resonance Imaging), PET (Positron

Emission Tomography) equipment, Angio equipment, and MRA (MR Angio) equipment. When using these devices, it is necessary to inject a chemical such as a contrast medium or physiological saline into the subject. Therefore, various chemical solution injection systems for automatically injecting chemical solutions have been proposed and put into practical use.

[0003] An example of a conventional chemical solution injection system will be described. The chemical injection system includes a chemical injection device having an injection head to which a chemical syringe is detachably attached, an MRI apparatus, and an image diagnostic apparatus.

[0004] The chemical syringe has a cylinder member having one end opened and a conduit portion formed at the other end, an open end force of the cylinder member, a piston member slidably inserted into the cylinder member, Have A flange is formed at one end of each of the cylinder member and the piston member.

[0005] The injection head includes a syringe mounting portion on which a cylinder member of the chemical syringe is detachably mounted, and a syringe drive mechanism that operates the held chemical syringe. The syringe drive mechanism has a rod that moves forward and backward by motor driving, and a piston pressing portion that holds the flange of the piston member and presses the piston member is provided at the tip thereof.

[0006] The chemical syringe is held on the injection head by mounting the cylinder member on the syringe mounting portion. On the other hand, the flange of the piston member is held by the piston pressing portion. An injection needle is connected to the conduit portion of the cylinder member via an extension tube. Subject with injection needle The rod is advanced with the blood vessel inserted into the blood vessel, and the piston member is pushed into the cylinder member, whereby the liquid medicine filled in the cylinder member is injected into the blood vessel of the subject.

[0007] When injecting a chemical solution to a subject, it is important to inject the chemical solution at a desired pressure in order to prevent damage to the chemical syringe due to excessive pressure applied to the chemical syringe. For this reason, the conventional chemical liquid injector has a built-in load cell, and the pressure acting on the piston member is detected by this load cell (see Patent Documents 1 and 2).

Patent Document 1: Japanese Patent Laid-Open No. 2003-290343

Patent Document 2: Japanese Patent Laid-Open No. 2005-74065

Disclosure of the invention

However, the load cell can detect the pressure in real time based on the change of the resistance value, and the detection circuit becomes complicated. In actual chemical injection operation, real-time detailed pressure data is often not required as long as the chemical syringe can be prevented from being damaged by excessive pressure. Further, if the syringe drive mechanism is operated in a state where the chemical syringe is normally attached, the chemical syringe may be damaged.

[0009] An object of the present invention is to provide a chemical solution injection device capable of preventing the chemical solution syringe from being damaged at the time of chemical solution injection with a simpler configuration.

[0010] In order to achieve the above object, a chemical injection device of the present invention operates a chemical syringe having a cylinder member filled with a chemical solution and a piston member slidably inserted into a cylinder member. This is a chemical injection device that injects a chemical into an injection target, and by holding the cylinder member in a detachable manner, the syringe mounting portion to which the chemical syringe is mounted and the piston member of the chemical syringe mounted on the syringe mounting portion are pressed. By doing so, a piston pressing portion that pushes the piston member into the cylinder member is provided. The piston pressing part protrudes so as to contact the flange holding part that holds the flange provided at the end part of the piston member and the flange that is held by the flange holding part, and is displaced by holding the flange. In addition, when the piston pressing portion pushes the piston member, the piston contact member provided so that it can be further displaced by the force received by the flange force, and the flange is held according to the displacement of the piston contact member. Before and after, and The flange mechanism also has a switch mechanism for switching the open / close state before and after reaching a predetermined force.

In the chemical injection device of the present invention configured as described above, a displaceable piston contact member is provided on the flange pressing portion so as to contact the flange held by the flange holding portion, and the switch mechanism The open / close state is switched as described above according to the displacement of the piston contact member. As a result, the piston contact member cover is moved while the flange of the piston member is held by the flange holding portion of the piston pressing portion and the piston pressing portion presses the piston member from the open / closed state of the switch mechanism. It is detected that the force received by the S flanger has reached a predetermined force. Here, the predetermined force that is detected by the switch mechanism and received by the flange contact member is set to a force that corresponds to the injection pressure at which the chemical solution injection pressure may damage the chemical syringe. In this case, it is detected whether or not the injection pressure has reached an injection pressure that may damage the chemical syringe.

[0012] In the chemical injection device according to the present invention, the piston pressing portion includes a hollow housing that houses the piston contact member in a displaceable manner by projecting the piston contact member from an opening provided at one end, and the housing When the piston contact member is in contact with the piston contact member and is displaced by receiving the flange force force, the movable member is disposed so as to be able to be displaced together with the piston contact member. And the position of the movable member is regulated so that the movable member does not come into contact with the piston contact member by the urging force of the urging member when the flange is not held by the flange holding portion. And a stagger that further includes According to this, the piston contact member can be provided so as to be displaced as described above.

[0013] The switch mechanism may have one double-throw type switch having an actuator that is actuated by displacement of the piston contact member, and each of the actuators that is actuated by displacement of the piston contact member may be provided. It has two single-throw switches equipped.

[0014] According to the present invention, it is possible to detect whether or not the force acting on the chemical syringe at the time of the chemical injection without using the load cell has reached a predetermined force. In addition, it is possible to detect the force force when the chemical syringe is normally attached. Therefore, when injecting chemicals, It is possible to effectively prevent the chemical syringe from being damaged with a simple configuration. Brief Description of Drawings

FIG. 1 is a perspective view of a chemical solution injection system according to an embodiment of the present invention.

FIG. 2 is a perspective view of the chemical liquid injector shown in FIG. 1.

FIG. 3 is a perspective view showing an injection head of the chemical injection device shown in FIG. 2 together with a chemical syringe.

4 is a cross-sectional view of the piston pressing portion shown in FIG.

FIG. 5A is a diagram schematically showing the contact state of each contact when the detection switch shown in FIG. 4 is a shorting type and is in the actuator force SFP.

FIG. 5B is a diagram schematically showing the contact state of each contact when the detection switch shown in FIG. 4 is a shorting type and is in the actuator force SOP1.

[FIG. 5C] FIG. 5C is a diagram schematically showing the contact state of each contact when the detection switch shown in FIG. 4 is a shorting type and is in the actuator force SOP2.

FIG. 5D is a diagram schematically showing the contact state of each contact when the actuator is at TTP when the detection switch shown in FIG. 4 is a shorting type.

FIG. 6 is a diagram illustrating switching timing when the detection switch shown in FIG. 4 is a shorting type.

FIG. 7A is a view for explaining the operation of the piston pressing portion shown in FIG.

7B is a diagram for explaining the operation of the piston pressing portion shown in FIG.

8 is a graph showing the relationship between the acting stress and the deflection of the compression spring in the piston pressing portion shown in FIG.

FIG. 9 is a diagram schematically showing the contact state of each contact when the actuator is between OP1 and OP2 when the detection switch shown in FIG. 4 is a non-shorting type.

FIG. 10 is a diagram showing the switching timing when the detection switch shown in FIG. 4 is a non-shorting type.

FIG. 11 is a cross-sectional view of an example of a piston pressing portion incorporating two detection switches.

FIG. 12A is a diagram for explaining the operation of the piston pressing portion shown in FIG.

12B is a diagram for explaining the operation of the piston pressing portion shown in FIG. 11. FIG. 13 is a perspective view of a piston pressing portion according to another embodiment of the present invention.

Explanation of symbols

[0016] 100 chemical injection device

110 injection head

118 Piston pressing part

121 Press body

124 Piston contact member

125 Movable plate

126 coil spring

130, 140, 150 detection switch

200C, 200P chemical syringe

210 Cylinder member

220 piston attachment

300 MRI machine

1000 chemical injection system

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIG. 1, a chemical liquid injection system 1000 includes a chemical liquid injection device 100 and an MRI apparatus 300 that is an imaging device. The MRI apparatus 300 includes an imaging unit 301 that is an imaging execution mechanism that captures a fluoroscopic image from a subject, and an imaging control unit 302 that controls the operation of the imaging unit 301.

As shown in FIG. 2, the chemical liquid injector 100 has an injection head 110, an injection head 110, and an injection control unit 101 electrically connected by a cable 102. The injection control unit 101 is configured as a computer that incorporates a CPU, ROM, RAM, and the like and controls the operation of the injection head 110 according to a predetermined program. Injection head 110 is supported on the upper end of caster stand 111 via movable arm 112.Injection control unit 101 has operation panel 103, touch panel 104, speaker unit 105, etc. on the front surface of housing 106. Has been placed. In addition, the injection control unit 101 includes The controller unit 107 is electrically connected via the cable 108.

As shown in FIG. 3, the injection head 110 detachably attaches two chemical syringes 200P and 200C, and operates the chemical syringes 200P and 200C attached to inject the chemical into the subject. The injection head 110 has a syringe mounting part 113 to which the chemical liquid syringes 200P and 200C are detachably mounted, and an injection head main body part 116 having a built-in syringe drive mechanism for operating the chemical liquid syringes 200P and 200C. Furthermore, in the chemical injection device of this embodiment, the operation of the injection head 110 is basically controlled by an input operation to the injection control unit 101 (see FIG. 2), but an operation panel 119 that receives a simple input operation is provided. The injection head main body 116 is also provided on the upper surface.

[0021] The chemical syringes 200C and 200P have a cylinder member 210 having a conduit portion 212 formed at the tip, and a piston member 220 that is slidably inserted into the cylinder member 210. Flanges 213 and 222 are formed at the rear ends of the cylinder member 210 and the piston member 220, respectively. In the present embodiment, one chemical solution syringe 200C is filled with a designing agent as a chemical solution, and the other chemical solution syringe 200P is filled with physiological saline as a chemical solution.

[0022] A branch pipe 230 can be connected to the chemical syringes 200C and 200P. The branch pipe 230 has a terminal portion branched into two and a tip portion concentrated into one. A catheter is connected to the distal end portion of the branch tube 230 via an extension tube.

[0023] From the injection head main body 116, two drive rods 117 that are driven independently from each other by a syringe drive mechanism protrude. Each drive rod 117 is driven using an ultrasonic motor (not shown) that does not generate a magnetic field even during operation as a drive source. The rotation of the ultrasonic motor is converted into a linear motion along the axial direction of the drive rod 117 by a motion transmission mechanism such as a screw mechanism (not shown). A piston pressing portion 118 that pushes the piston member 220 into the cylinder member 210 by pressing the end surface (specifically, the flange 221) of the piston member 220 is attached to the distal end portion of the drive rod 117. Further, the piston pressing portion 118 is configured so that the flange 221 of the piston member 220 can be detachably held.

The syringe mounting portions 113 are arranged corresponding to the drive rods 117, respectively. It has two U-shaped groove-like recesses 114 extending along the moving direction. Each recess 114 has a first portion 114a for detachably holding the cylinder members 210 of the chemical liquid syringes 200P and 200C, and a second portion 114b on which the piston pressing portion 118 slides.

[0025] At the boundary portion between the first portion 114a and the second portion 114b, a flange member that fixes the cylinder member 210 to a predetermined position of the syringe mounting portion 113 by fitting the flange 213 of the cylinder member 210 into the boundary portion. A coupling mechanism 115 is provided.

When the liquid syringes 200P and 200C are attached to the syringe attachment portion 113 and the drive rod 117 is operated with the piston pressing portion 118 holding the flange 221 of the piston member 220, the piston member 220 becomes the cylinder member 210. Move forward and backward. As a result, the cylinder member 210 can be filled with a chemical solution or the filled chemical solution can be discharged.

[0027] In each component of the injection head 110, a portion that can be made of a nonmagnetic material is made of a nonmagnetic material, and a portion that cannot be made of a nonmagnetic material is magnetically shielded. For example, metal parts such as an ultrasonic motor are made of a nonmagnetic metal such as a phosphor bronze alloy, a titanium alloy, or a magnesium alloy. The casing of the injection head 110 is made of a non-magnetic material.

Here, the piston pressing portion 118 will be described with reference to FIG. 4, which is a cross-sectional view along the moving direction.

[0029] The piston pressing portion 118 has a pressing portion main body 121 having an opening 121a formed at one end surface in the direction of arrow M, which is the direction of movement by the drive rod 117 (see FIG. 3). The other end surface side of the pressing portion main body 121 is open, and is configured in a cylindrical shape as a whole. The open other end surface of the pressing portion main body 121 is closed by a lid member 122, and the pressing portion main body 121 and the lid member 122 constitute a casing having a hollow structure of the piston pressing portion 118. ing.

[0030] On the outer peripheral surface of the pressing portion main body 121, a pair of flange holding members 123 arranged to face each other for engaging with a flange 221 (see FIG. 3) of the piston member 220 are provided with a piston pressing portion. One end side force of 118 is also provided to protrude. A wedge-shaped flange receiving claw 123a is formed in the body at the tip of the flange holding member 123, and the flange receiving claw 123a engages with the flange 221. [0031] A piston contact member 124, a movable plate 125, a coil spring 126, and a detection switch 130 are arranged in the hollow portion of the piston pressing portion 220.

[0032] The piston contact member 124 has a flat plate portion and a convex portion provided in the central region thereof, the flat plate portion is located in the hollow portion of the piston pressing portion 118, and the convex portion has an opening 121a. And is provided so as to be movable in the direction of the arrow M in a direction protruding from the pressing portion main body 121. When the piston pressing portion 118 presses the piston member 220, the tip end surface of the convex portion presses the end surface of the piston member 220, that is, the flange 221.

[0033] The diameter of the flat plate portion is larger than the diameter of the opening 121a. Therefore, the maximum protruding amount of the piston contact member 124 from the pressing portion main body 121 is defined by the surface of the piston contact member 124 having the flat plate convex portion coming into contact with the inner surface of the pressing portion main body 121. The height of the convex portion of the piston contact member 124 is such that the piston contact member 124 protrudes most from the pressing portion main body 121, and the distance dl from the tip surface force of the convex portion in the direction of arrow M to the flange receiving claw 123a is the piston member. It is set to be smaller than the thickness of the flange 221 of 220.

[0034] The movable plate 125 is a ring-shaped member provided so as to be in contact with the piston contact member 124. When the piston contact member 124 is displaced toward the movable plate 125 while the piston contact member 124 is in contact with the piston contact member 124, , It is displaced together with the piston contact member 124. The movable plate 125 is biased toward the piston contact member 124 by a coil spring 126 provided between the movable plate 125 and the lid member 122.

However, at least in the state where the piston contact member 124 protrudes most from the pressing portion main body 121, the inner surface of the pressing portion main body 121 is disposed on the piston contact member 124 so that the movable plate 125 does not contact the piston contacting member 124. A step portion with which the movable plate 125 abuts is provided at an end portion on the side where the plate is provided. This step portion regulates the position of the movable plate 125 so that the movable plate 125 does not contact the piston contact member 124 by the biasing force of the coil spring 126 when the flange 221 is not supported by the piston pressing portion 118. It functions as a stagger. In the present embodiment, the stepped portion is provided so that the coil spring 126 is supported in a compressed state within a range without reaching the maximum deflection. Therefore, in this state, the coil spring 126 can be further compressed by acting on the coil spring 126 with a stress larger than the stress acting on the coil spring 126. The stress that can further compress the coil spring 126 When acting on the piston contact member 124, the piston contact member 126 can be further displaced.

[0036] The detection switch 130 is a DT (double throw) type micro switch, and includes a case 131 containing a plurality of contacts (not shown) for opening and closing operation, an actuator 132 for opening and closing the contact mechanism, Have The case 131 is fixed at a fixed position in the pressing portion main body 121 by an attachment member (not shown).

In this embodiment, the actuator 132 is a lever-like member, and is rotated with respect to the case 131 while being urged by a spring (not shown) so that the tip portion is in contact with the piston contact member 124. It is provided as possible. Therefore, the actuator 132 urges the piston contact member 124 in a direction in which the convex portion protrudes from the pressing portion main body 121. Thus, in a state where the flange 221 of the piston member 220 is held by the flange holding member 123, the piston contact member 124 is in contact with the flange 221 of the piston member 220. The form of the actuator 132 is not limited to a lever, and any form used as an actuator for a switch, such as a push button or a slide member, can be applied.

Next, the detection switch 130 used in the present embodiment will be described with reference to FIGS. 5A to 5D and FIG.

As shown in FIG. 5A, the detection switch 130 includes first to third fixed contacts 133 to 135 that are electrically independent from each other, and at least a second of the fixed contacts 133 to 135. A movable contact 136 is provided in the case 131 so as to be movable with respect to the fixed contacts 133 to 135 so as to be electrically connected to the fixed contact 134. The movable contact 136 is connected to the actuator 132 via an operating mechanism (not shown), and takes the states shown in FIGS. 5A to 5D as the actuator 132 rotates.

Furthermore, the detection switch 130 has a NO terminal (normally open terminal) 137, a COM terminal (common terminal) 138, and an NC terminal (normally closed terminal) 139 as external terminals. The NO terminal 137 is electrically connected to the first fixed contact 133. The COM terminal 138 is electrically connected to the second fixed contact 134. The NC terminal 139 is electrically connected to the third fixed contact 135.

In the present embodiment, as the detection switch 130, the switching timing is a shorting timing. Is used. The shorting type is a type that is short-circuited during switching by the contact point before switching and the contact force to be switched from now on. Hereinafter, the operation of the detection switch 130 will be described.

FIG. 5A shows a state where the actuator 132 is at FP (free position). In this state, the movable contact 136 is not in contact with the first fixed contact 133 and the force that is in contact with the second fixed contact 134 and the third fixed contact 135. Therefore, the output from the NO terminal 137 is off, and the output from the NC terminal 139 is on.

[0043] When external force is applied to the actuator 132 and the actuator 132 rotates, as shown in FIG. 5B, the movable contact 136 moves in the direction of the arrow and maintains the state of contact with the third fixed contact 135. Meanwhile, the first fixed contact 133 is contacted. That is, the movable contact 136 is in contact with all the fixed contacts 133 to 135. The position of the actuator 132 when the movable contact 136 comes into contact with the first fixed contact 135 is referred to as OP1 (first operation position). In this state, the output from the NO terminal 137 and the output from the NC terminal 139 are both turned on.

When the actuator 132 is further rotated, as shown in FIG. 5C, the movable contact 136 is further moved in the direction of the arrow and is separated from the third fixed contact 135. The position of the actuator 132 immediately before the movable contact 136 moves away from the third fixed contact 135 is referred to as OP2 (second operation position). When the movable contact 136 moves away from the third fixed contact 135, the output from the NC terminal 139 is turned off. Even after the movable contact 136 moves away from the third fixed contact 135, the movable contact 136 remains in contact with the first and second fixed contacts 133, 134, and the output from the NO terminal 137 remains on. It has become.

[0045] FIG. 5D shows a state where the actuator 132 is further rotated and moved to the TTP (operation limit position). In this state, the movable contact 136 is in contact only with the first and second fixed contacts 133 and 134 and is not in contact with the third fixed contact 135. Therefore, the output from the NO terminal 137 is on, but the output from the NC terminal 139 is off! /.

FIG. 6 shows the output from the NO terminal 137 and the output from the NC terminal 139 in the series of operations described above with the position of the actuator 132 as the horizontal axis. Referring to FIG. 6, while the actuator 132 moves from the FP via the OP1 and OP2 to the TTP, N It can be seen that the output from C terminal 139 is on between FP and OP2, and the output from NO terminal 137 is on between OP1 and TTP. Therefore, between OP1 and OP2, the output from NC terminal 139 and the output from NO terminal 137 are both ON. Outputs from the NO terminal 137 and the NC terminal 139 are input to the injection control unit 101 (see FIG. 2).

[0047] When the external force applied to the actuator 132 is removed, the FP is returned to the FP by a biasing force of a spring (not shown).

[0048] Next, the detection operation using the above-described detection switch 130 will be described.

First, as shown in FIG. 4, before the piston member 220 is attached to the piston pressing portion 118, the actuator 132 of the detection switch 130 has the piston contact member 124 whose convex portion is the opening of the pressing portion main body 121. The piston contact member 124 is pressed against the inner surface of the pressing portion main body 121 by urging in the direction protruding from the portion 121a. The actuator 132 has not reached OP 1 and the detection switch 130 has only the NC terminal 139 turned on.

[0050] If the outputs from the NO terminal 137 and the NC terminal 139 are both off at this stage, the injection control unit 101 (see FIG. 2) determines that an abnormality has occurred in the detection switch 130 or the like. Then, the fact that an error has occurred is displayed on the touch panel 104 (see FIG. 2). In addition, when both the output from NO terminal 137 and NC terminal 139 are ON, injection control unit 101 (see Fig. 2) determines that an abnormality has occurred in detection switch 130, etc. Display on the touch panel 104 that the error occurred.

[0051] At this stage, since only the NC terminal 139 needs to be on, the positional relationship between the actuator 132 and the piston contact member 124 may be set so that the actuator 1 32 is in the FP. .

Next, as shown in FIG. 3, the liquid syringes 200 P and 200 C filled with the liquid medicine are attached to the injection head 110. Specifically, the second member 114a of the recess 114 holds the cylinder member 210 of the chemical syringe 200P (200C), and the flange 221 of the piston member 220 is connected to the piston pressing portion 118 as shown in FIG. 7A. The flange holding member 123 is engaged. When the piston member 220 is attached to the piston pressing portion 118, the piston contact member 124 is pushed into the piston pressing portion 118 by the flange 221. Piston contact member 124 is pushed As a result, the actuator 132 rotates in the direction of the arrow to a position that exceeds OP1 but does not reach OP2.

Thereby, the detection switch 130 turns on not only the NC terminal 139 but also the output from the NO terminal 137. When the output from the NO terminal 137 is turned on, the injection control unit 101 determines that the chemical syringe 200P (200C) is normally attached, and the injection head 110 of the injection head 110 is subsequently operated according to the input operation from the operator. Control the behavior. On the other hand, if the output from the NC terminal 137 remains off, the injection control unit 101 determines that the chemical syringe 200P (200C) is not attached, and displays that fact on the touch panel 104.

In this state, the piston contact member 124 may be in contact with the movable plate 125 or may be separated from the movable plate 125. However, the convex portion of the piston contact member 124 is in a position protruding from the opening 121a of the pressing portion main body 121.

When the drive rod 117 (see FIG. 3) is advanced in a state where the piston member 220 is mounted on the piston pressing portion 118, the pressure by the piston pressing portion 118 acts on the piston member 220. By this pressure, the piston member 220 is pushed into the cylinder member 210, and the chemical liquid filled in the cylinder member 210 is pushed out from the cylinder member 210.

When the piston pressing portion 118 pushes the piston member 220 into the cylinder member 210, the piston contact member 124 receives a reaction force in the direction to be pushed into the pressing portion main body 121 from the piston member 220. By this reaction force, the piston contact member 124 presses the movable plate 125 in a direction in which the coil spring 126 is compressed. As described above, the coil spring 126 is supported by using the step portion provided in the pressing portion main body 121 as a stopper, and therefore, as shown in the graph of FIG. The deflection of the spring 126 is constant. When the stress acting on the coil spring 126 exceeds a certain stress, the piston contact member 124 further compresses the coil spring 126 via the movable plate 125 as shown in FIG. It is pushed in. When the piston contact member 124 is pushed in, the actuator 132 further rotates in the direction of the arrow according to the pushing amount.

[0057] The push-in amount of the piston contact member 124 depends on the magnitude of the reaction force from the piston member 220, that is, the magnitude of the stress acting on the piston member 220. The pushing amount of 124 becomes large. The reaction force from the piston member 220 is Corresponds to the injection pressure acting on the syringe 200P, 200C. Here, the protrusion amount of the end surface force of the pressing portion main body 121 of the piston contact member 124 is such that the piston contact member 124 is positioned until the tip surface of the piston contact member 124 is flush with the end surface of the pressing portion main body 121. While pushed by the piston member 220, the actuator 132 is set to reach OP2.

[0058] Further, the spring characteristic of the coil spring 126 is that when the stress applied to the piston member 220 by the piston contact member 124 becomes a predetermined stress, that is, the injection pressure is a predetermined injection pressure. When set, the actuator 132 is set to reach OP2. In this embodiment, when the injection pressure is 1. 18 X 10 ⁵ Pa (l. 2 kg / cm ² ), which is an injection pressure that may cause the chemical syringes 200P and 200C to be damaged, the actuator 132 The spring characteristics of the coil spring 126 are set so that reaches OP2.

[0059] When the actuator 132 reaches OP2, the output from the NC terminal 139 is turned off. When the output from the NC terminal 139 is turned off, the injection control unit 101 determines that the injection pressure has reached the limit pressure, stops the operation of the injection head 110, and a pressure abnormality occurs in the touch panel 104. A message is displayed.

As described above, in the present embodiment, the piston contact member 124 that can be displaced by applying pressure to the piston member 220, and the piston contact based on the displacement of the piston contact member 124. A piston switch 118 includes a detection switch 130 that switches between open and closed states before and after the force that the member 124 receives from the flange 221 reaches a predetermined force. Thereby, the pressure abnormality which acts on the chemical | medical solution syringe 200P, 200C at the time of chemical | medical solution injection | pouring which does not use a load cell is detectable. As a result, an inexpensive chemical injection device 100 with a simple configuration is provided. However, after the piston member 220 is held by the piston pressing portion 118, the piston contact member 124 is not displaced at the initial stage before reaching a certain force received from the piston member 220. It is possible to stably detect pressure abnormalities due to.

[0061] Further, the piston contact member 124 is displaced before and after the piston pressing portion 118 holds the flange 221 of the piston member 220, and the detection switch 130 is in contact with the piston according to the pressure applied to the piston member 220. Attaching and removing piston member 220 separately from displacement of member 124 The open / close state is also switched by the displacement of the piston contact member 124 due to the above. Therefore, the chemical injection device 100 according to the present embodiment can detect not only the pressure abnormality but also the force force that the chemical syringes 200P and 200C are normally attached and detached. As a result, the chemical syringes 200P and 200C can be prevented from being damaged by performing the chemical injection operation with the chemical syringes 200P and 200C incompletely attached.

In the present embodiment, an example is shown in which a step portion is provided in the pressing portion main body 121 and the compression spring 126 is supported in a compressed state by this, but the step portion is not provided and no external force is applied. The compression spring 126 may be supported by. In this case, the spring constant of the coil spring 126 is set so that the piston pressing member 118 can hold the piston member 220 while pushing the piston contact member 124 against the biasing force of the coil spring 126. Alternatively, if there is room in the space, the piston contact member 124, the movable plate 125, and the coil are not compressed so that the coil spring 126 is not compressed even if the piston contact member 124 is displaced when the piston member 220 is held. Set the dimensions of the spring 126.

[0063] In this embodiment, a 1S non-shorting type switch using a shorting type switch may be used as the detection switch 130. As shown in FIG. 9, when the position of the actuator 132 is between OP1 and OP2, the non-shorting type detection switch is connected to either the first fixed contact 133 or the third fixed contact 135. Does not touch. The switching timing is as shown in Fig. 10. The difference from the shorting type is that the output from the NC terminal 139 and the output from the NO terminal 137 are both turned off between OP1 and OP2. .

[0064] When a non-shorting type detection switch is used, detection of whether or not the chemical syringe 200P (200C) is attached is performed when the output from the NC terminal 139 is turned off. Pressure abnormality is detected when the output from the NO terminal 137 is turned on.

Further, in this embodiment, a force that detects an abnormal pressure when a chemical syringe 200P (200C) is attached and detached and a chemical solution is injected using one double-throw detection switch 130, as shown in FIG. Two single-throw detection switches 140 and 150 can also be used. These detection switches 140 and 150 are replaced with the detection switch 130 shown in FIG. It is installed in the pressure unit 118.

[0066] In the single-throw detection switches 140 and 150, the actuator has one OP. The single throw type detection switches 140 and 150 are further divided into the NO (normally open) type and NC (normally closed) type.

[0067] For example, when one detection switch 140 is an NO type and the other detection switch 150 is an NC type, the detection switches 140 and 150 are installed as follows. As shown in FIG. 12A, the NO-type detection switch 140 is installed such that when the piston member 220 is mounted, the actuator moves to a position exceeding OP due to the displacement of the piston contact member 124. The NC type detection switch 150 does not reach the OP when the piston member 220 is attached, but as shown in FIG. 12B, the displacement of the piston contact member 124 when a pressure abnormality to be detected occurs. Install the actuator so that it reaches OP. By installing each of the detection switches 140 and 150 in this way, pressure abnormalities at the time of attaching / detaching the chemical syringe and injecting the chemical solution are detected in the same sequence as when using the shorting type detection switch 130 described above. can do.

[0068] Alternatively, if the position of the above-mentioned NO-type detection switch 140 and the position of the NC-type detection switch 150 are interchanged, the chemical solution is processed in the same sequence as when using the non-shorting-type detection switch described above. It is possible to detect pressure abnormalities during syringe attachment / detachment and chemical injection.

[0069] Each of the detection switches 140 and 150 may be the NO type or the NC type. In either case, as in the case of combining NO type and NC type as described above, each detection switch 140, 150 is installed, and the detection sequence is changed accordingly. It is possible to detect pressure abnormalities when attaching / detaching and injecting chemicals.

FIG. 13 shows a perspective view of a piston pressing portion according to another embodiment of the present invention.

The piston pressing portion 160 shown in FIG. 13 differs from the above-described embodiment in the structure of the flange holding member 163 and the drive rod 16 for moving the piston pressing portion 160 forward and backward.

5 is a holding position of the piston member of the chemical syringe relative to 5.

[0072] In the above-described embodiment, the flange holding portion in the present invention has both sides of the piston pressing portion. In this embodiment, the flange holding member 163 is configured as a receiving member that supports the downward force by placing the portion of the piston member provided with the flange. . As described above, the flange holding portion can have any configuration as long as the piston pressing portion 160 can move the piston member forward and backward together with the piston pressing portion 160 moving forward and backward.

In the above-described embodiment, the piston pressing portion holds the piston member coaxially with the drive rod 165. However, in this embodiment, the piston pressing portion 160 is the piston driving rod 165. The piston member is held at a position different from the axial center.

[0074] In addition, the piston pressing portion 160 has a hollow casing 161, and the piston contact member 162 is provided in the casing 161 so as to be displaceable by protruding the tip. In addition, the switch mechanism as described in the above-described embodiment is provided in the casing 161, and the like, as in the above-described embodiment.

[0075] The present invention can cover various changes that are not limited to the above-described embodiments. For example, the number of chemical syringes that can be attached to the injection head is not limited to two, and may be one or three or more. The concave portions 114, the drive rods 117, and the like are provided in a number corresponding to the number of chemical syringes to be mounted. The size of the chemical syringe that can be attached to the injection head 110 is also arbitrary, and the size of the recess 114, the stroke of the drive rod 117, and the like are set so as to match the size of the chemical syringe to be attached. When multiple chemical syringes are installed, the size of each chemical syringe may be different.

Furthermore, in the above-described embodiment, the description has been made assuming that the present invention is applied to an MRI apparatus, but the present invention is applicable even if the fluoroscopic imaging apparatus is a CT scanner apparatus, PET apparatus, angio apparatus, or MRA apparatus. be able to.

Claims

The scope of the claims

[1] A chemical injection device that operates a chemical syringe having a cylinder member that is filled with a chemical solution and a piston member that is slidably inserted into the cylinder member and injects the chemical solution into an injection target. Because

A syringe mounting portion on which the chemical syringe is mounted by detachably holding the cylinder member;

A piston pressing portion that presses the piston member into the cylinder member by pressing the piston member of the chemical syringe mounted on the syringe mounting portion; and

The piston pressing part is

A flange holding portion for holding a flange provided at an end of the piston member; a flange holding portion that protrudes in contact with the flange held by the flange holding portion; and displacement by holding the flange; And a piston contact member provided so that the piston pressing part can be further displaced by the force received by the flanger by pressing the piston member;

Switches that open and close according to the displacement of the piston contact member before and after holding the flange, and after the flange force is received before reaching a predetermined force. Mechanism,

A chemical injection device.

[2] The piston pressing portion is

A hollow housing that projects the piston contact member from an opening provided at one end and accommodates the piston contact member in a displaceable manner;

A movable member provided inside the housing so as to be displaceable together with the piston contact member by the piston contact member being displaced by receiving the flange force force in a state where the piston contact member is in contact. ,

A biasing member that biases the movable member toward the piston contact member; and when the flange is not held by the flange holding portion, the movable member is in contact with the piston by the biasing force of the biasing member. So that the movable member is not in contact with the member. A stagger that regulates the position,

The chemical injection device according to claim 1, further comprising:

[3] The switch mechanism has one double-throw type switch including an actuator that is operated by the displacement of the piston contact member to take the first operation position and the second operation position, and the switch includes: When the flange is held by the flange holding portion, the actuator reaches the first operating position, and the force received by the flange force reaches a predetermined force. The chemical solution injection device according to claim 1 or 2, wherein the chemical solution injection device is arranged to reach an operating position.

4. The chemical solution injection device according to claim 3, wherein the switch is a shorting type switch.

5. The chemical solution injection device according to claim 3, wherein the switch is a switching timing shortcut type switch.

[6] The switch mechanism has two single-throw switches each having an actuator that is actuated by displacement of a piston contact member, one of the two switches being connected to the flange holding portion. When the flange is held, the actuator is installed so as to reach the operating position. On the other hand, when the force received by the flange force reaches a predetermined force, the actuator reaches the operating position. The chemical injection device according to claim 1 or 2, wherein the chemical injection device is installed in the device.