Injection system

Abstract

To provide an infusion system that more reliably prevents blood reflux. [Solution] The infusion system comprises an infusion device (608) for injecting a first drug solution and a second drug solution, a first baseline (508) through which the first drug solution flows, a second baseline (509) through which the second drug solution flows, a subject line (503) connected to the first baseline and the second baseline, a closing mechanism (200a) located in the subject line for closing the internal flow path of the drug solution circuit (2500), and a one-way valve (V5) located in the subject line. In the subject line, the one-way valve is located downstream of the closing mechanism.

Description

Technical Field

[0001] The present invention relates to a closing mechanism for closing a flow path, a chemical solution circuit, and an infusion system.

Background Art

[0002] Patent Document 1 describes first and second blocking mechanisms that individually block a first tube connected to a first syringe and a second tube connected to a second syringe. The first blocking mechanism has a first holding member and a first pressing member, and the second blocking mechanism has a second holding member and a second pressing member. The first holding member is disposed opposite the first pressing member via the first tube, and the second holding member is disposed opposite the second pressing member via the second tube. When injecting a contrast agent from the first syringe into a subject, the second tube is blocked by the second blocking mechanism. Similarly, when injecting physiological saline from the second syringe into a subject, the first tube is blocked by the first blocking mechanism.

[0003] Patent Document 2 also describes a clamping mechanism that crushes a flexible tube to block a flow path. This clamping mechanism has a pair of clamp members that press the tube, and the clamp members are moved by a driving force from a driving source to crush the flexible tube. Further, Patent Document 2 describes a clamp member having a corner portion that abuts on the tube, a clamp member having a V-shaped groove that is substantially complementary to the corner portion, and a clamp member having a protruding portion that protrudes in a curved surface shape.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional drug solution circuits, measures are taken to prevent the subject's blood flowing back through the tube (backflow) from reaching the area upstream of the closure. However, in recent years, there has been a need for drug solution circuits that can more reliably prevent blood backflow and can be more easily attached to infusion devices. [Means for solving the problem]

[0006] To solve the above problems, the closing mechanism, drug solution circuit, and injection system, as examples of the present invention, each have the following features.

[0007] A closing mechanism for closing an internal flow path in a chemical solution circuit, as one example of the present invention, comprises a sliding member having a flow path and a housing that slidably accommodates the sliding member, wherein the sliding member has a recess formed on its outer circumference between the inlet and outlet of the flow path. Another example of the present invention is a closing mechanism for closing an internal flow path in a chemical solution circuit, comprising a sliding member having a flow path and a housing that slidably accommodates the sliding member, wherein a hole is formed in the sliding member corresponding to the flow path, and the sliding member is configured to be thicker around the hole.

[0008] Furthermore, another example of the present invention is a drug solution circuit comprising a first baseline through which a first drug solution flows, a second baseline through which a second drug solution flows, a subject line connected to the first baseline and the second baseline, and a closing mechanism for closing the internal flow path of the drug solution circuit, wherein the closing mechanism comprises a sliding member having a flow path and a housing that slidably accommodates the sliding member, the sliding member having a recess formed so as not to contact the housing, and the recess being formed on the outer circumference of the sliding member between the inlet and outlet of the flow path.

[0009] Furthermore, another example of the present invention is an injection system comprising an injection device for injecting a first drug solution and a second drug solution, a first baseline through which the first drug solution flows, a second baseline through which the second drug solution flows, a subject line connected to the first baseline and the second baseline, and a closing mechanism for closing the internal flow path of the drug solution circuit, wherein the closing mechanism comprises a sliding member having a flow path and a housing that slidably accommodates the sliding member, the sliding member having a recess formed so as not to contact the housing, and the recess being formed on the outer circumference of the sliding member between the inlet and outlet of the flow path. [Effects of the Invention]

[0010] This makes it possible to provide a closure mechanism, drug circuit, and infusion system that can more reliably prevent blood backflow.

[0011] Further features of the present invention will become apparent from the following description of the exemplary embodiments shown with reference to the accompanying drawings. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of the drug solution circuit according to the first embodiment of the present invention. [Figure 2] This is a schematic perspective view of the first closure mechanism. [Figure 3] This is a schematic cross-sectional view of the first closure mechanism. [Figure 4] This is a schematic bottom view of the first closing mechanism. [Figure 5] This is a schematic perspective view of the second closure mechanism. [Figure 6] This is a schematic cross-sectional view of the second closure mechanism. [Figure 7] This is a schematic bottom view of the second closure mechanism. [Figure 8] This is a schematic perspective view of the air detection unit. [Figure 9] This is a schematic cross-sectional view of the air detection unit. [Figure 10] This is a schematic cross-sectional view of the air detection unit. [Figure 11]Schematic diagram of the disposable circuit according to the second embodiment of the present invention. [Figure 12] Schematic diagram of the reuse circuit. [Figure 13] Schematic diagram of the reuse circuit. [Figure 14] Schematic perspective view of the first closing mechanism. [Figure 15] A is a schematic cross-sectional view of the first closing mechanism in the closed state, and B is a schematic cross-sectional view of the first closing mechanism in the open state. [Figure 16] Schematic bottom view of the first closing mechanism. [Figure 17] Schematic perspective view of the first and second pistons. [Figure 18] Schematic exploded view of the second piston. [Figure 19] Schematic perspective view of the second closing mechanism. [Figure 20] A is a schematic cross-sectional view of the second closing mechanism in the closed state, and B is a schematic cross-sectional view of the second closing mechanism in the open state. [Figure 21] Schematic exploded view of the connector with a rotor. [Figure 22] Schematic cross-sectional view of the connector with a rotor. [Figure 23] Schematic diagram of the liquid reservoir cap connected to the third male connector. [Figure 24] Schematic perspective view of the liquid reservoir cap. [Figure 25] Schematic diagram of the chemical solution circuit according to the third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions of the components, etc. described in the following embodiments are arbitrary and can be changed according to the configuration of the device to which the present invention is applied or various conditions. Also, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below. In this specification, the pressure resistance means, for example, 6.895×105 High pressures above Pa (100 psi), especially 6.895 × 10 6 This refers to the property of being able to withstand ultra-high pressure of Pa (1000 psi) or more. In the description of the injection device in this specification, the side on which the syringe is mounted corresponds to the front, and the opposite side corresponds to the rear. Unless otherwise specified, the upstream side corresponds to the injection device side, and the downstream side corresponds to the subject side.

[0014] [First Embodiment] Figure 1 is a schematic diagram of a drug solution circuit 500 used, for example, in cardiac catheterization. This drug solution circuit 500 includes a first closure section 100a and a second closure section 100b. However, for the sake of explanation, the first drive unit 130a that operates the first closure mechanism 120a of the first closure section 100a and the second drive unit 130b that operates the second closure mechanism 120b of the second closure section 100b are shown schematicly.

[0015] The drug solution circuit 500 is used to draw a first medical drug solution, such as a contrast agent, and a second medical drug solution, such as physiological saline, from drug solution supply sources into syringes and inject them into the subject. The drug solution circuit 500 is connected to a contrast agent chamber 601 as the first drug solution supply source and a physiological saline chamber 602 as the second drug solution supply source.

[0016] The drug solution circuit 500 also includes a contrast agent line 501 connected to the contrast agent chamber 601 and a saline line 502 connected to the saline chamber 602. The contrast agent line 501 is connected to the contrast agent chamber 601 via a spike needle 607 with a drip chamber. The saline line 502 is connected to the saline chamber 602 via a spike needle 607 with a drip chamber. Alternatively, the contrast agent line 501 and the saline line 502 may each be connected to the contrast agent chamber 601 and the saline chamber 602 via a drip chamber and a connector. The contrast agent line 501 and the saline line 502 also have tubes through which the drug solution flows. Here, a line is a flow path for liquid and includes various components through which the liquid flows (e.g., various tubes, T-connectors, male connectors, female connectors, one-way valves, connecting tubes, mixing devices, stopcocks, spike needles with drip chambers, closing mechanisms, air detection units, and rotators).

[0017] The contrast agent chamber 601 is, for example, a bottle-shaped container filled with contrast agent and is used suspended from a suspension device (not shown) (for example, a suspension device attached to the injection device 608). The contrast agent flowing out of the contrast agent chamber 601 drips into the drip chamber of the spike needle with drip chamber 607 and flows through the contrast agent line 501. The saline chamber 602 is, for example, a bag-shaped container filled with saline solution and is used suspended from a suspension device (not shown). The saline solution flowing out of the saline chamber 602 drips into the drip chamber of the spike needle with drip chamber 607 and flows through the saline line 502.

[0018] Furthermore, an injection device 608 is connected to the drug solution circuit 500 to aspirate drug solutions from the contrast agent chamber 601 and the saline chamber 602, and to inject the drug solutions into the subject. This injection device 608 is equipped with a contrast agent syringe 604 as the first syringe and a saline syringe 605 as the second syringe. The contrast agent syringe 604 and the saline syringe 605 are fixed in a syringe protective case with plungers (not shown) attached. The syringe protective case is then fixed to the injection device 608 by a syringe clamper.

[0019] The injection device 608 has a presser (not shown) that engages with the plunger of the syringe. The injection device 608 moves the plunger forward or backward. The injection device 608 also has an operating unit 609. This operating unit 609 is equipped with operating buttons such as a forward button, a backward button, a start button, and a priming button. The injection device 608 is rotatably connected to a caster stand placed on the floor. This allows the injection device 608 to be rotated to a position where the front of the injection device 608 faces the floor (downward position) and a position where the rear of the injection device 608 faces the floor (upward position). Furthermore, the injection device 608 may be equipped with a tilt sensor. When this tilt sensor detects that the injection device 608 is in the downward position, priming and injection of the drug solution are permitted. When the tilt sensor detects that the injection device 608 is in the upward position, aspiration of the drug solution is permitted. Preferably, the injection device 608 is connected to a caster stand so that it can rotate left and right. Alternatively, the injection device 608 may be connected to a ceiling suspension member so that it is suspended from the ceiling, or it may be connected to a catheter table or catheter rail.

[0020] Furthermore, the infusion device 608 is connected to a control device (not shown) by wire or wirelessly, for example, via a head cable. This control device has a touch panel and functions as a controller for the infusion device 608. The control device also has pre-stored data for operation patterns (infusion protocols) and drug solution data. When injecting drug solution into a subject, the operator uses the touch panel to input the subject's physical data, such as infusion rate, infusion volume, infusion time, and body weight, as well as drug solution data, such as iodine content and type of drug solution, into the control device.

[0021] The control device calculates the optimal infusion conditions based on the input data and pre-stored data. Based on the calculated infusion conditions, the control device determines an infusion protocol, including the amount of medication to be injected into the subject. Then, following the operator's instructions, the infusion device 608 injects the medication according to the determined infusion protocol. Alternatively, the control device can retrieve the infusion protocol and other data from an external storage medium.

[0022] Furthermore, the drug solution circuit 500 includes a first baseline 508 through which the contrast agent, as the first drug solution, flows between the infusion device 608 and the subject line 503. This first baseline 508 has a first tube 504, a first upstream tube 506a connected to the first tube 504, and a first downstream tube 507a connected to the male connector on the downstream side of the first upstream tube 506a. The first upstream tube 506a is connected to the first tube 504 and the contrast agent line 501. The female connector on the upstream side of the first tube 504 is connected to the tip of the contrast agent syringe 604, or to a tube (not shown) connected to the contrast agent syringe 604. The first tube 504 is also connected to the first upstream tube 506a and the contrast agent line 501 by a first T-connector T1.

[0023] Furthermore, the drug solution circuit 500 includes a second baseline 509 through which saline solution flows as a second drug solution between the infusion device 608 and the subject line 503. This second baseline 509 includes a second tube 505, a second upstream tube 506b connected to the second tube 505, and a second downstream tube 507b connected to the male connector on the downstream side of the second upstream tube 506b. The second upstream tube 506b is connected to the second tube 505 and the saline line 502. The female connector on the upstream side of the second tube 505 is connected to the tip of the saline syringe 605, or to a tube (not shown) connected to the saline syringe 605. The second tube 505 is also connected to the second upstream tube 506b and the saline line 502 by a second T-connector T2.

[0024] Furthermore, the drug solution circuit 500 includes a subject line 503 connected to a first baseline 508 and a second baseline 509. This subject line 503 has, in order from upstream, a mixing device S, a first closure 100a, an air detection unit 400, a third downstream tube 507c (e.g., a pressure-resistant tube), and a stopcock C. The first closure 100a is connected to the air detection unit 400 and the second closure 100b by a third T-connector T3. The air detection unit 400 is also connected to the third downstream tube 507c via a connecting pipe. A stopcock C or a three-way stopcock is attached to the third downstream tube 507c via a rotator.

[0025] The subject line 503 is connected via a stopcock C to a catheter (not shown) that is punctured or inserted into the subject. The tip of this catheter is transported, for example, to the coronary artery in cardiac catheterization. The drug solution is then injected into the coronary artery from the tip of the catheter. The subject line 503 is also connected to the first baseline 508 and the second baseline 509 via a mixing device S (for example, "SPIRAL FLOW" (registered trademark) manufactured by Nemoto Kyorindo Co., Ltd.). Alternatively, the subject line 503 can also be connected via a T-connector.

[0026] Furthermore, the drug solution circuit 500 includes a second closure 100b as a transducer line. This second closure 100b is connected to the subject line 503 and the first closure 100a via a third T-connector T3. The second closure 100b is also connected to a transducer 603. This transducer 603 is connected to a display (not shown) that displays the waveform of the subject's pulse in order to detect the subject's blood pressure and monitor the pulse.

[0027] The subject line 503, the second closure 100b, the first baseline 508, and the second baseline 509 are configured to be disposable in part. For example, the first downstream tube 507a of the first baseline 508 is disposable and is detachably connected to the first upstream tube 506a via the first one-way valve V1. Similarly, the second downstream tube 507b of the second baseline 509 is disposable and is detachably connected to the second upstream tube 506b via the second one-way valve V2. This allows the portions of the drug solution circuit 500 located downstream of the first upstream tube 506a and downstream of the second upstream tube 506b to be configured to be disposable.

[0028] Furthermore, the subject line 503 can be detachably connected to the first baseline 508 and the second baseline 509. The second closure 100b can also be detachably connected to the subject line 503. This allows the subject line 503 and the second closure 100b to be configured as disposable. However, the first drive unit 130a and the second drive unit 130b are reusable.

[0029] The first tube 504, the first upstream tube 506a, the first downstream tube 507a, the second tube 505, the second upstream tube 506b, the second downstream tube 507b, and the third downstream tube 507c are pressure-resistant tubes. These pressure-resistant tubes have, for example, an inner layer made of polyamide and an outer layer made of polyurethane. The first closure section 100a and the second closure section 100b have pressure-resistant braided tubes or pressure-resistant tubes. These pressure-resistant braided tubes are 8.274 × 10⁻¹⁰ 6 Preferably, the tubes can withstand high pressures of Pa (1200 psi), and for example, they have an inner and outer layer made of polyurethane with polyester braids woven into it. The first tube 504, the first upstream tube 506a, the first downstream tube 507a, the second tube 505, the second upstream tube 506b, the second downstream tube 507b, and the third downstream tube 507c may be pressure-resistant braided tubes.

[0030] The chemical solution circuit 500 is equipped with a first one-way valve V1, a second one-way valve V2, a third one-way valve V3, and a fourth one-way valve V4. Each of these one-way valves is a pressure-resistant one-way valve that allows flow downstream and blocks flow upstream. In Figure 1, the triangular marks on each one-way valve indicate the direction in which the chemical solution is blocked, with the tip of the triangle pointing in the direction in which the chemical solution does not flow. For example, the triangle on the third one-way valve V3 connected to the contrast agent line 501 means that the contrast agent does not flow toward the contrast agent chamber 601 (upstream direction).

[0031] The first one-way valve V1 is attached to the first downstream tube 507a. The first downstream tube 507a is connected to the first upstream tube 506a via the first one-way valve V1. This first one-way valve V1 allows flow toward the subject line 503 and blocks flow toward the contrast agent syringe 604.

[0032] The second one-way valve V2 is attached to the second downstream tube 507b. The second downstream tube 507b is connected to the second upstream tube 506b via the second one-way valve V2. This second one-way valve V2 allows flow toward the subject line 503 while blocking flow toward the saline syringe 605.

[0033] The third one-way valve V3 is attached to the first T-connector T1. Therefore, the contrast agent line 501 is connected to the first tube 504 via the third one-way valve V3 and the first T-connector T1. This third one-way valve V3 allows flow toward the contrast agent syringe 604 and toward the first upstream tube 506a, while blocking flow toward the contrast agent chamber 601.

[0034] The fourth one-way valve V4 is attached to the second T-connector T2. Therefore, the saline line 502 is connected to the second tube 505 via the fourth one-way valve V4 and the second T-connector T2. This fourth one-way valve V4 allows flow toward the saline syringe 605 and toward the second upstream tube 506b, while blocking flow toward the saline chamber 602.

[0035] These one-way valves ensure that if the contrast agent is drawn upstream of the first baseline 508, i.e., toward the contrast agent syringe 604, the contrast agent flows from the contrast agent line 501 toward the contrast agent syringe 604. If the contrast agent is discharged from upstream of the first baseline 508 toward its downstream side, i.e., toward the subject line 503, the contrast agent does not flow back into the contrast agent line 501.

[0036] If saline solution is drawn upstream of the second baseline 509, i.e., toward the saline syringe 605, the saline solution will flow from the saline line 502 toward the saline syringe 605. If saline solution is discharged from upstream of the second baseline 509 toward its downstream side, i.e., toward the subject line 503, the saline solution will not flow back into the saline line 502.

[0037] Furthermore, the drug solution circuit 500 includes a first closing section 100a and a second closing section 100b as closing sections that close the flow path within the circuit. Each closing section comprises a pair of tubes (a first pair of tubes 110a and a second pair of tubes 110b), a closing mechanism for closing the flow path (a first closing mechanism 120a and a second closing mechanism 120b), and a drive unit for operating the closing mechanism (a first drive unit 130a and a second drive unit 130b). The closing section can close the internal flow path of the closing mechanism connected to the pair of tubes. The drive unit is wirelessly or wiredly connected to an external controller and operates in response to a control signal from the controller, operating the closing mechanism to close the internal flow path. In the following description, the injection device 608 functions as the controller.

[0038] The drug solution circuit 500 functions as part of an injection system comprising a transducer 603 and an injection device 608. This injection system allows for the automatic injection of contrast agent and saline solution. The method of using the drug solution circuit 500 will be described below. In the following description, the injection device 608 can advance or retract its two pressers separately, or advance or retract them simultaneously.

[0039] [Air bleeding] Before injecting the drug solution, priming is performed to remove air. Priming is initiated by the operator pressing the priming button on the control panel 609 of the injection device 608. Alternatively, priming may be performed automatically by the injection device 608 at a predetermined timing. Furthermore, the operator can also perform priming manually by performing a predetermined operation.

[0040] Before priming, the operator opens stopcock C to allow air to be removed from the catheter connected to the patient line 503. Then, when priming begins, the infusion device 608 advances the plunger of the contrast agent syringe 604, discharging the contrast agent from the contrast agent syringe 604. This fills, for example, the first tube 504, the first upstream tube 506a, and the first downstream tube 507a (first baseline 508) with contrast agent. Alternatively, the infusion device 608 may fill the contrast agent from the first tube 504 to the patient line 503. The infusion device 608 may also aspirate the contrast agent from the contrast agent chamber 601 before discharging the contrast agent. In this case, the infusion device 608 retracts the plunger of the contrast agent syringe 604. This fills the contrast agent syringe 604 with contrast agent via the contrast agent line 501 and the first tube 504. However, if the air sensor 606 detects that there is not enough contrast agent in the contrast agent chamber 601, the aspiration of the contrast agent is prohibited.

[0041] Next, the infusion device 608 advances the plunger of the saline syringe 605, discharging saline from the saline syringe 605. This fills the second tube 505, the second upstream tube 506b, and the second downstream tube 507b (second baseline 509), as well as the second closure 100b and the subject line 503 with saline. Alternatively, the infusion device 608 may fill only the second baseline 509 with saline. The infusion device 608 may also aspirate saline from the saline chamber 602 before discharging the saline. In this case, the infusion device 608 retracts the plunger of the saline syringe 605. This fills the saline syringe 605 with saline via the saline line 502 and the second tube 505. However, if the air sensor 606 detects that there is not enough saline in the saline chamber 602, aspirating saline is prohibited.

[0042] This priming process fills the entire drug solution circuit 500 with the drug solution and removes air. The injector 608 may perform priming by simultaneously discharging the contrast agent and saline solution instead of discharging the contrast agent first. Alternatively, the injector 608 may perform priming by discharging the saline solution first and then the contrast agent.

[0043] [Injection of medication] The control unit of the infusion device 608 has a touch panel, and once the amount of drug solution and the infusion protocol are determined, it displays predetermined data or graphs on the touch panel. The operator checks the display on the touch panel and presses the confirmation button on the touch panel or the start button on the operation unit 609 if they wish to start injecting the drug solution. The control unit then transmits a drug solution injection command to the infusion device 608.

[0044] Before injecting the drug solution, the injection device 608 controls the second closure section 100b to close the internal flow path so that the contrast agent or saline solution does not flow toward the transducer 603. At this time, the first closure section 100a is in an open state and does not close the flow path. If necessary, the injection device 608 controls the first closure section 100a to open the internal flow path.

[0045] Subsequently, the injection device 608 advances the plunger of the contrast agent syringe 604, discharging the contrast agent from the contrast agent syringe 604. At this time, the third one-way valve V3 blocks the flow toward the contrast agent chamber 601. As a result, the contrast agent flows into the mixing device S via the first tube 504, the first upstream tube 506a, and the first downstream tube 507a (first baseline 508).

[0046] Furthermore, when contrast agent and saline solution are injected simultaneously, the injection device 608 advances the plunger of the saline syringe 605 to discharge saline solution from the syringe 605. At this time, the fourth one-way valve V4 blocks the flow toward the saline chamber 602. As a result, saline solution flows into the mixing device S via the second tube 505, the second upstream tube 506b, and the second downstream tube 507b (second baseline 509). Thus, the contrast agent and saline solution flow into the mixing device S and are mixed within the mixing device S. Subsequently, the mixed solution of contrast agent and saline solution is injected into a predetermined imaging site (e.g., the subject's coronary artery) via the subject line 503 and catheter.

[0047] Furthermore, when injecting the drug solution, the injection device 608 controls the second closure section 100b to close the internal flow path so that the drug solution does not flow toward the transducer 603. At this time, the first closure section 100a is open. If necessary, the injection device 608 controls the first closure section 100a to open the internal flow path. Then, the injection device 608 advances the plunger of the contrast agent syringe 604 to discharge the contrast agent from the contrast agent syringe 604.

[0048] [flash] After the contrast agent injection is complete, the injection device 608 advances the plunger of the saline syringe 605 to discharge saline from the saline syringe 605. At this time, the second closure 100b is closed. If necessary, the injection device 608 controls the second closure 100b to close the internal flow path. The saline is then injected into the designated imaging site via the second tube 505, the second upstream tube 506b, and the second downstream tube 507b (second baseline 509), as well as the subject line 503 and catheter. This causes the contrast agent to be flushed with saline.

[0049] [Blood pressure detection] Subsequently, the infusion device 608 controls the first closure 100a to close the internal flow path. For example, the infusion device 608 closes the internal flow path after the residual pressure in the drug solution circuit 500 has sufficiently decreased. At the same time, the infusion device 608 controls the second closure 100b to open the internal flow path. This releases the pressurized state on the subject side of the transducer 603. Then, a blood pressure route is established through the subject line 503 and the second closure 100b. As a result, the transducer 603 becomes capable of detecting blood pressure. Alternatively, a flow sensor described in International Publication No. 2017 / 038575 may be used instead of the transducer 603.

[0050] In this configuration, the first closure 100a blocks the flow of liquid upstream of the first closure 100a. Therefore, backflow into the region upstream of the first closure 100a is prevented. Furthermore, the flow of liquid upstream of the first one-way valve V1 and the second one-way valve V2 is blocked by both one-way valves. This more reliably prevents blood from flowing into the circuit upstream of the first one-way valve V1 and the second one-way valve V2.

[0051] [Aspiration of medication] When the amount of contrast agent in the contrast agent syringe 604 falls below a predetermined amount, the injection device 608 aspirates the contrast agent. That is, the injection device 608 aspirates the contrast agent from the contrast agent chamber 601 towards the contrast agent syringe 604 by retracting the plunger of the contrast agent syringe 604. At this time, the third one-way valve V3 allows flow toward the contrast agent syringe 604 via the first tube 504 and flow toward the first upstream tube 506a. The third one-way valve V3 also blocks the flow toward the contrast agent chamber 601 via the contrast agent line 501. The first one-way valve V1 allows flow toward the first downstream tube 507a but blocks the flow toward the contrast agent syringe 604.

[0052] When the amount of saline in the saline syringe 605 falls below a predetermined amount, the infusion device 608 aspirates saline. That is, the infusion device 608 retracts the plunger of the saline syringe 605, aspirating saline from the saline chamber 602 towards the saline syringe 605. At this time, the fourth one-way valve V4 allows flow toward the saline syringe 605 via the second tube 505 and flow toward the second upstream tube 506b. The fourth one-way valve V4 also blocks the flow toward the saline chamber 602 via the saline line 502. The second one-way valve V2 allows flow toward the second downstream tube 507b but blocks the flow toward the saline syringe 605.

[0053] After aspiration, the infusion device 608 can discharge the aspirated contrast agent toward the first baseline 508 by advancing the plunger of the contrast agent syringe 604. Similarly, the infusion device 608 can discharge the aspirated saline toward the second baseline 509 by advancing the plunger of the saline syringe 605.

[0054] [1st closing part] Next, the first closing mechanism 120a of the first closing section 100a will be described with reference to Figures 2 to 4. Figure 2 is a schematic perspective view showing the first closing mechanism 120a in a closed state. Figure 3 is a schematic cross-sectional view showing the first closing mechanism 120a in a closed state, showing a longitudinal cross-section along the central axis of the internal flow path of the first closing mechanism 120a. Figure 4 is a schematic bottom view showing the first closing mechanism 120a in a closed state. Although the first closing mechanism 120a is connected to the first tube pair 110a, the first tube pair 110a is omitted from Figures 2 to 4 for the sake of explanation.

[0055] The first closing mechanism 120a, which closes the internal flow path, comprises first heads 121a1 and 121a2 pressed by the presser of the first drive unit 130a, a substantially cylindrical first piston 122a1 (first moving member) on which the first head 121a1 is formed, and a substantially cylindrical first piston 122a2 (second moving member) on which the first head 121a2 is formed. Furthermore, the first closing mechanism 120a comprises a pair of first conduit sections 123a, which are joined to a first tube pair 110a (not shown). The first tube pair 110a can be joined to the first conduit sections 123a, for example, by solvent bonding. In Figure 2, the right side corresponds to the injection device 608 side, and the left side corresponds to the subject side.

[0056] Furthermore, the first closure mechanism 120a includes a first housing 124a having a pair of holes for receiving the first pistons 122a1 and 122a2. A first reinforcing rib 125a is formed on the body of the first housing 124a, extending along the outer circumference of the first housing 124a. A triangular mark is formed on the first reinforcing rib 125a. This triangular mark indicates the direction in which the drug solution flows, with the tip of the triangle pointing in the direction in which the drug solution flows (i.e., towards the subject). Alternatively, the triangular mark can be formed on another part, for example, the upper surface of the first housing 124a. Note that the first closure mechanism 120a may have three or more pistons. If there are three or more pistons, the first housing 124a will have the same number of holes as pistons.

[0057] As shown in Figure 3, the first pistons 122a1 and 122a2 are housed in the first housing 124a so as to be slidable in the sliding direction A indicated by the arrow. That is, the first pistons 122a1 and 122a2 are mounted so as to be retractable relative to the first housing 124a. Specifically, to open the internal passages (first passages 126a1 and 126a2) of the first closing mechanism 120a, the first pistons 122a1 and 122a2 are moved downward in Figure 3. Then, the first passage 126a1 of the first piston 122a1 and the first passage 126a2 of the first piston 122a2 are brought into contact with the openings in the first conduit section 123a, respectively. As a result, the pair of first conduit sections 123a communicate via the first passages 126a1 and 126a2, and the internal passages are opened. On the other hand, when the first pistons 122a1 and 122a2 are moved upward in Figure 3, the sides of the first pistons 122a1 and 122a2 face the openings in the first conduit section 123a, respectively, and the internal flow path is closed.

[0058] The first piston 122a1, located on the injection device 608 side (right side in Figure 3), is equipped with a first flow path 126a1 having a long, approximately elliptical cross-section in the sliding direction A. On the other hand, the first piston 122a2, located on the subject side (left side in Figure 3), is equipped with a first flow path 126a2 having a short, approximately circular cross-section in the sliding direction A. Therefore, in the sliding direction A of the first pistons 122a1 and 122a2, the first flow path 126a1 of the first piston 122a1 is larger than the first flow path 126a2 of the first piston 122a2. The upper end positions of the first flow paths 126a1 and 126a2 are set so that they are the same distance from the corresponding opening in the first conduit section 123a. In other words, the formation positions of the first channels 126a1 and 126a2 are set such that when the upper ends of the first channels 126a1 and 126a2 face the opening in the first conduit section 123a, the upper end of the first channel 126a2 also faces the opening in the first conduit section 123a. Furthermore, the upper end positions of the first channels 126a1 and 126a2 are set so that they are the same distance from the hole section 128.

[0059] When opening the internal flow path, the first pistons 122a1 and 122a2 are lowered simultaneously. Therefore, at the moment when the lower end of the first flow path 126a1 faces the opening in the first conduit section 123a, the side of the first piston 122a2 faces the opening in the first conduit section 123a. As a result, the flow path is opened on the injection device 608 side (upstream side), but not on the subject side (downstream side). Subsequently, the first flow path 126a2 faces the opening in the first conduit section 123a. This opens the flow path on both the upstream and downstream sides.

[0060] Alternatively, the first flow path 126a1 may be formed below the first flow path 126a2. That is, the distance from the first head 121a1 to the first flow path 126a1 in the first piston 122a1 may be set to be longer than the distance from the first head 121a2 to the first flow path 126a2 in the first piston 122a2. Furthermore, in the sliding direction A, the first head 121a1 may be longer than the first head 121a2 so that the top surface of the first head 121a1 is pressed by the presser of the first drive unit 130a before the top surface of the first head 121a2. Furthermore, the first drive unit 130a may be controlled so that the first head 121a1 is pressed before the first head 121a2. Furthermore, the first drive unit 130a may be controlled so that the downward speed of the first piston 122a1 is faster than the downward speed of the first piston 122a2. That is, the first drive unit 130a may be controlled so that the first head 121a1 moves faster than the first head 121a2. In these cases as well, the flow path can be opened on the injection device 608 side before the subject side. In these cases, the first flow path 126a1 may have the same size and shape as the first flow path 126a2. The first drive unit 130a may also be equipped with two pressers that press the first head 121a1 and the first head 121a2, respectively. In this case, the first drive unit 130a may also be equipped with two motors that drive the two pressers.

[0061] In this way, the flow path is opened on the injection device 608 side before it is opened on the subject side. As a result, even if backflow blood reaches the first piston 122a2, when the flow path is opened, the blood is pushed towards the subject by the drug solution. Therefore, it is possible to prevent it from reaching the first piston 122a1. In addition, when the flow path is closed, the first flow path 126a1 of the first piston 122a1 is isolated from the opening in the first conduit section 123a. Therefore, when the flow path is closed, backflow blood does not reach the first flow path 126a1. As a result, it is possible to more reliably prevent backflow upstream of the first closure section 100a.

[0062] When closing the internal flow path, at the moment when the lower end of the first flow path 126a2 moves away from the opening in the first conduit section 123a (its side faces the opening), the first flow path 126a1 is still facing the opening in the first conduit section 123a. Therefore, the first flow path 126a2 is closed, but the first flow path 126a1 is not. Subsequently, the first flow path 126a1 moves away from the opening in the first conduit section 123a (its side faces the opening). As a result, both the first flow paths 126a1 and 126a2 are closed.

[0063] Furthermore, the first pistons 122a1 and 122a2 are each provided with a pair of first O-rings 127a arranged to sandwich the first flow paths 126a1 and 126a2 in the sliding direction A. This prevents liquid leakage from between the sides of the first pistons 122a1 and 122a2 and the inner surface of the first housing 124a. To more reliably prevent liquid leakage, at least the first piston 122a2 may have a lower first O-ring 127a formed to face the opening in the first conduit section 123a. That is, the lower first O-ring 127a may be positioned to shield the opening in the first conduit section 123a when closed. Alternatively, a rubber sealing member may be placed on at least the side of the first piston 122a2 at a position that shields the opening in the first conduit section 123a when closed.

[0064] A hole 128 is formed approximately in the center of the first housing 124a, which, together with the first flow paths 126a1 and 126a2, constitutes the internal flow path of the first closure section 100a. That is, the hole 128 is formed between a pair of holes that receive the first pistons 122a1 and 122a2. When the flow path is open, both ends of this hole 128 face the first flow paths 126a1 and 126a2, respectively. This opens the internal flow path of the first closure section 100a. A one-way valve may be provided in this hole 128 to allow flow from the injection device 608 side to the subject side and to block flow from the subject side to the injection device 608 side.

[0065] As shown in Figure 4, a pair of first alignment portions 129a1 and 129a2 protruding laterally are formed on the lower part of the first pistons 122a1 and 122a2. A groove is formed on the inner surface of the first housing 124a, having an inner surface shape complementary to the outer surface of the first alignment portions 129a1 and 129a2. By inserting the first alignment portions 129a1 and 129a2 into this groove, the first pistons 122a1 and 122a2 can be positioned correctly. This prevents misalignment between the opening in the first conduit portion 123a and the first flow paths 126a1 and 126a2.

[0066] The pair of first alignment portions 129a1 are formed at different positions from the pair of first alignment portions 129a2. Specifically, the pair of first alignment portions 129a2 are formed at positions offset by approximately 90° in the counterclockwise direction on the outer circumference of the first piston 122a1. On the other hand, the pair of first alignment portions 129a1 are formed at positions offset by approximately 180° in the counterclockwise direction. This prevents the first piston 122a1 from being mistakenly attached to the subject. Alternatively, the pair of first alignment portions 129a1 may be formed at positions offset by approximately 90° from each other, and the pair of first alignment portions 129a2 may be formed at positions offset by approximately 180° from each other.

[0067] [Second closing part] Next, with reference to Figures 5 to 7, the second closing mechanism 120b of the second closing section 100b will be described. This second closing section 100b differs from the first closing section 100a in that it has one second piston 122b (third moving member).

[0068] Figure 5 is a schematic perspective view showing the second closure mechanism 120b in a closed state. Figure 6 is a schematic cross-sectional view showing the second closure mechanism 120b in a closed state, showing a longitudinal cross-section along the central axis of the internal flow path of the second closure mechanism 120b. Figure 7 is a schematic bottom view showing the second closure mechanism 120b in a closed state. The second closure mechanism 120b is connected to the second tube pair 110b, but for the sake of explanation, the second tube pair 110b is not shown in Figures 5 to 7.

[0069] The second closing mechanism 120b, which closes the internal flow path, comprises a second head 121b pressed by the presser of the second drive unit 130b, and a substantially cylindrical second piston 122b on which the second head 121b is formed. Furthermore, the second closing mechanism 120b comprises a pair of second conduit sections 123b, which are joined to a second pair of tubes 110b (not shown). The second pair of tubes 110b can be joined to the second conduit sections 123b, for example, by solvent bonding. In Figure 5, the right side corresponds to the subject side, and the left side corresponds to the transducer 603 side.

[0070] Furthermore, the second closing mechanism 120b includes a second housing 124b having a hole for receiving the second piston 122b. A second reinforcing rib 125b is formed on the body of the second housing 124b, extending around the outer circumference of the second housing 124b. A triangular mark is formed on the second reinforcing rib 125b. This triangular mark indicates the direction in which the chemical solution flows, with the tip of the triangle pointing in the direction in which the chemical solution flows (i.e., towards the transducer 603). Alternatively, the triangular mark can be formed on another part, for example, the upper surface of the second housing 124b. Note that the number of second pistons 122b is not limited to one, but may be two or more. If there are two or more second pistons 122b, the second housing 124b has the same number of holes as the second pistons 122b.

[0071] As shown in Figure 6, the second piston 122b is housed in the second housing 124b so as to be slidable in the sliding direction A indicated by the arrow. That is, the second piston 122b is mounted to the second housing 124b so as to be retractable. Specifically, to open the internal flow path of the second closing mechanism 120b, the second piston 122b is moved downward in Figure 6. Then, the second flow path 126b of the second piston 122b is brought into contact with the opening in the second conduit section 123b. As a result, the pair of second conduit sections 123b communicate via the second flow path 126b, and the internal flow path is opened. On the other hand, when the second piston 122b is moved upward in Figure 6, the side of the second piston 122b faces the opening in the second conduit section 123b, and the internal flow path is closed. That is, the second flow path 126b constitutes the internal flow path of the second closing section 100b.

[0072] The second piston 122b is equipped with a second flow path 126b having a substantially circular cross-section. That is, the second piston 122b has the same structure as the first piston 122a2 on the subject side (left side in Figure 3) of the first closing mechanism 120a. As a result, both pistons can be manufactured using the same method.

[0073] The second piston 122b is provided with a pair of second O-rings 127b arranged to sandwich the second flow path 126b in the sliding direction A. This prevents leakage of fluid from between the side surface of the second piston 122b and the inner surface of the second housing 124b. To more reliably prevent leakage of fluid, the lower second O-ring 127b may be formed to face the opening in the second conduit section 123b. That is, the lower second O-ring 127b may be positioned so that it shields the opening in the second conduit section 123b when in the closed state. Alternatively, a rubber sealing member may be placed on the side surface of the second piston 122b in a position that shields the opening in the second conduit section 123b when in the closed state.

[0074] As shown in Figure 7, a pair of second alignment portions 129b protruding laterally are formed on the lower part of the second piston 122b. A groove having an inner shape complementary to the outer shape of the second alignment portion 129b is formed on the inner surface of the second housing 124b. By inserting the second alignment portion 129b into this groove, the second piston 122b can be positioned correctly. This prevents misalignment between the opening in the second conduit portion 123b and the second flow path 126b.

[0075] [Air detection] The drug solution circuit 500 includes ultrasonic air sensors 606 (Figure 1) positioned between the contrast agent chamber 601 and the drip chamber spike needle 607, between the saline chamber 602 and the drip chamber spike needle 607, and in the subject line 503. When the air sensor 606 detects the presence of air bubbles, it transmits a signal to the infusion device 608. Upon receiving the signal, the infusion device 608 performs at least one of the following actions: stop the injection of the drug solution, stop the aspiration of the drug solution, or issue a notification (warning) of air detection. Furthermore, the air sensors 606 may also be positioned in the first downstream tube 507a and the second downstream tube 507b.

[0076] The drug solution circuit 500 may be equipped with a sensor to monitor the amount of drug solution in each chamber. For example, if the amount of drug solution in each chamber falls below a predetermined amount, the sensor transmits a signal to the injection device 608. Upon receiving the signal, the injection device 608 performs at least one of the following actions: stop aspirating the drug solution, stop injecting the drug solution, or issue a notification prompting the replacement of each chamber.

[0077] An air sensor 606 positioned on the test line 503 detects the presence of air bubbles in an air detection unit 400 positioned between the transmitter and receiver. To improve the accuracy of bubble detection, the air detection unit 400 includes a flat section 402, as shown in Figure 8. The air detection unit 400 is positioned relative to the air sensor 606 such that the flat section 402 is located between the transmitter and receiver of the air sensor 606. Such an air detection unit 400 is manufactured, for example, by bonding together two polycarbonate components formed by molding. The air detection unit 400 will now be described with reference to Figures 8 through 10.

[0078] Figure 8 is a schematic perspective view of the air detection unit 400. Figure 9 is a schematic cross-sectional view of the center of the air detection unit 400, showing a cross-section parallel to the plane 406 of the flat section 402 and along the longitudinal direction of the air detection unit 400. Figure 10 is a schematic cross-sectional view of the center of the air detection unit 400, showing a cross-section perpendicular to the plane 406 of the flat section 402 and along the longitudinal direction of the air detection unit 400. The air detection unit 400 is equipped with a pair of tubes 401 (Figure 1), but for the sake of explanation, the pair of tubes 401 are not shown in Figures 8 to 10.

[0079] The air detection unit 400 comprises a flat section 402 having a pair of flat surfaces 406 on its outer side, and a pair of conduit sections 403 that are respectively joined to a pair of tubes 401 (not shown). These pair of conduit sections 403 are formed at both ends of the air detection unit 400, flanking the flat section 402. The flat section 402 has a substantially elliptical cross-sectional shape and rounded sides.

[0080] As shown in Figure 9, the flat section 402 has an internal space 405 that is wider than the opening 404 in the conduit section 403. That is, in a cross-section parallel to the plane 406 of the flat section 402, the width of the internal space 405 is longer than the opening 404. This internal space 405 has a symmetrical octagonal cross-sectional shape. Also, as an example, in a cross-section parallel to the plane 406, the width of the flat section 402 is longer than the conduit section 403. Furthermore, the internal space 405 is sized to correspond to the detection surface of the air sensor 606.

[0081] As shown in Figure 10, in a cross-section perpendicular to the pair of planes 406, the thickness of the flat portion 402 is thinner than that of the conduit portion 403. Also, as an example, in this cross-section, the height of the internal space 405 is longer than that of the opening portion 404. The cross-sectional area of ​​the internal space 405 can be set to be approximately equal to the cross-sectional area of ​​the conduit portion 403.

[0082] The drug solution circuit 500 described above can more reliably prevent blood backflow and, due to its fewer parts, can be more easily attached to the infusion device 608. It is preferable that each tube through which the drug solution injected from the infusion device 608 flows is a pressure-resistant tube. However, each tube may be a tube that can withstand a relatively low pressure, for example, 10 to 20 psi.

[0083] [Second Embodiment] Figures 11 to 13 are schematic diagrams of the chemical solution circuit 2500 according to the second embodiment. Figure 11 shows a disposable circuit of the chemical solution circuit 2500, and Figures 12 and 13 show a reusable circuit of the chemical solution circuit 2500. In describing the second embodiment, the differences from the first embodiment will be explained, and the same reference numerals will be used for components described in the first embodiment, and their descriptions will be omitted. Unless otherwise specified, components with the same reference numerals will perform substantially the same operation and function, and their effects will also be substantially the same.

[0084] The drug solution circuit 2500 includes a first closure section 200a and a second closure section 200b. In Figure 11, for the sake of explanation, the first drive unit 230a that drives the first closure mechanism 220a of the first closure section 200a and the second drive unit 230b that drives the second closure mechanism 220b of the second closure section 200b are shown schematically. The drug solution circuit 2500 also includes a contrast agent line 501 (Figure 12), a saline line 502 (Figure 13), a first baseline 508 through which the contrast agent as the first drug solution flows, a second baseline 509 through which saline solution as the second drug solution flows, and a subject line 503 connected to the first baseline 508 and the second baseline 509. The first closure section 200a is located in this subject line 503.

[0085] The first closure section 200a of the chemical solution circuit 2500 includes a first closure mechanism 220a for closing an internal flow path and a first drive unit 230a for driving the first closure mechanism 220a. The second closure section 200b of the chemical solution circuit 2500 is connected to the transducer 603 and also includes a second closure mechanism 220b for closing an internal flow path. Furthermore, the second closure section 200b includes a second tube pair 110b and a second drive unit 230b for driving the second closure mechanism 220b.

[0086] The first baseline 508 includes a first upstream tube 506a, a first female connector F1 connected to a first male connector M1 (Figure 12) attached to the first upstream tube 506a, and a first downstream tube 507a to which the first female connector F1 is attached. The second baseline 509 includes a second upstream tube 506b, a second female connector F2 connected to a second male connector M2 (Figure 13) attached to the second upstream tube 506b, and a second downstream tube 507b to which the second female connector F2 is attached.

[0087] When aspirating the drug solution, disposable one-way valved tubes can be connected between the first female connector F1 and the first male connector M1, and between the second female connector F2 and the second male connector M2. Furthermore, when injecting the contrast agent, a manual or electric clamp can be attached to the second downstream tube 507b to close the internal flow path of the second downstream tube 507b. This prevents the contrast agent from flowing into the saline line 502.

[0088] The subject line 503 has, in order from the upstream side, a mixing device S, an air detection unit 2400, a first closure unit 200a, a third downstream tube 507c, and a third male connector M3. This subject line 503 is connected to a catheter (not shown) that is punctured or inserted into the subject via the third male connector M3. The subject line 503 is also connected to the first baseline 508 and the second baseline 509 via the mixing device S. Note that the subject line 503 may also be connected to the first baseline 508 and the second baseline 509 via other tubes or the like.

[0089] The first closure section 200a is connected to the third downstream tube 507c and the second closure section 200b via the third T-connector T3. In the second embodiment, the first closure section 200a is also connected to the third T-connector T3 via the fifth one-way valve V5. This fifth one-way valve V5 allows the drug solution to flow toward the subject and blocks the flow toward the first closure section 200a (upstream direction). Furthermore, the air detection unit 2400 in the second embodiment is positioned between the mixing device S and the first closure section 200a.

[0090] The air detection unit 2400 is, for example, a pressure-resistant tube, preferably a mesh tube. An air sensor 606 is positioned opposite the air detection unit 2400, and by pressing the air sensor 606 against it, the mesh tube can be deformed to conform to the shape of the detection unit, thereby improving the accuracy of air detection. This air sensor 606 detects the presence of air bubbles in the air detection unit 2400, which is positioned between the transmitting unit and the receiving unit. Furthermore, by positioning the air sensor 606 upstream of the first closing mechanism 220a, the flow path can be closed by the first closing mechanism 220a when air is detected. Alternatively, the air sensor 606 may be positioned in the mixing device S.

[0091] Furthermore, the drug solution circuit 2500 includes a second closure section 200b as a transducer line. This second closure section 200b is connected to the third downstream tube 507c via a third T-connector T3. The second closure section 200b is also connected to the transducer 603 via a third female connector F3. In addition, the drug solution circuit 2500 is equipped with a contrast agent syringe 604 and a saline syringe 605, and an injection device 608 for injecting the contrast agent (first drug solution) and saline solution (second drug solution) is connected to it. The drug solution circuit 2500 then functions as part of an injection system comprising the transducer 603 and the injection device 608. This injection system allows for the automatic injection of contrast agent and saline solution. Note that the second closure section 200b may be connected to the transducer 603 via other tubes or the like.

[0092] The subject line 503, the second closure 200b, the first baseline 508, and the second baseline 509 are configured to be disposable in part. Specifically, the first downstream tube 507a of the first baseline 508 is detachably connected to the first upstream tube 506a. Similarly, the second downstream tube 507b of the second baseline 509 is detachably connected to the second upstream tube 506b. As a result, the subject line 503, the second closure 200b, the first downstream tube 507a, and the second downstream tube 507b can be replaced with new ones after use. However, the first drive unit 230a and the second drive unit 230b are reused.

[0093] [Control of the closing mechanism] The injection device 608 of the drug solution circuit 2500 is wirelessly or wiredly connected to the first drive unit 230a and the second drive unit 230b. This injection device 608 functions as an external controller and controls the first closing unit 200a and the second closing unit 200b as follows, for example.

[0094] The injection device 608 is wired or wirelessly connected to a control device (not shown), and priming is performed before the injection of the drug solution to remove air. This priming is initiated, for example, by the operator pressing a priming button displayed on the touch panel of the control device. Priming fills the entire drug solution circuit 2500 with the drug solution and removes air. Alternatively, the operator can perform priming by operating the control unit 609 of the injection device 608.

[0095] Furthermore, priming includes, as an example, modes 1 to 4. In mode 1, the first upstream tube 506a and the first downstream tube 507a (first baseline 508) are filled with contrast agent. In mode 2, the second upstream tube 506b and the second downstream tube 507b (second baseline 509) and the subject line 503 are filled with saline. In mode 3, each line except the second closure 200b (transducer line) is filled with contrast agent and saline. In mode 4, the second upstream tube 506b and the second downstream tube 507b (second baseline 509), the second closure 200b, and the subject line 503 are filled with saline and / or contrast agent.

[0096] After air is removed, the first closure section 200a and the second closure section 200b automatically close the internal flow path. Therefore, the injection device 608 controls the first closure section 200a to open the internal flow path before injecting the drug solution. If the internal flow path is not automatically closed, the injection device 608 controls the second closure section 200b to close the internal flow path before injecting the drug solution, so that the contrast agent or saline solution does not flow toward the transducer 603. Subsequently, the injection device 608 advances the plunger of the contrast agent syringe 604 to discharge the contrast agent from the contrast agent syringe 604. When injecting the contrast agent and saline solution simultaneously, the injection device 608 further advances the plunger of the saline solution syringe 605 to discharge the saline solution from the saline solution syringe 605.

[0097] After the injection of the drug solution is complete, the first closure section 200a automatically closes the internal flow path. Therefore, when flushing the contrast agent with physiological saline, the injection device 608 controls the first closure section 200a to open the internal flow path. Subsequently, the injection device 608 advances the plunger of the physiological saline syringe 605 to discharge the physiological saline from the syringe 605. In addition, the injection of the contrast agent and the injection of physiological saline (including flushing) may be performed automatically and continuously. In this case, the injection device 608 maintains the open state of the first closure section 200a, and therefore the opening of the internal flow path of the first closure section 200a is omitted. If the internal flow path of the second closure section 200b is not automatically closed, the injection device 608 controls the second closure section 200b to close the internal flow path before flushing.

[0098] When detecting blood pressure after drug injection, the infusion device 608 controls the second closure section 200b to open the internal flow path. For example, the infusion device 608 closes the internal flow path of the second closure section 200b after the residual pressure in the drug circuit 2500 has sufficiently decreased. Alternatively, after drug injection, the infusion device 608 may open the internal flow path of the second closure section 200b at the same time that the first closure section 200a closes the internal flow path.

[0099] Thus, after the injection of the drug solution is complete, the first closure section 200a automatically closes the internal flow path, blocking the flow of liquid upstream of the first closure section 200a. Therefore, backflow into the region upstream of the first closure section 200a can be prevented. In addition, the flow of liquid upstream of the fifth one-way valve V5 is blocked by the fifth one-way valve V5. This makes it possible to more reliably prevent blood from flowing into the circuit upstream of the fifth one-way valve V5.

[0100] [Reused circuit] As shown in Figure 12, a contrast agent chamber 601 is connected to the contrast agent line 501 of the drug solution circuit 2500. The contrast agent line 501 has a spike needle 607 with a drip chamber. The contrast agent flowing out of the contrast agent chamber 601 drips into the drip chamber of the spike needle 607 and flows through the contrast agent line 501. The contrast agent line 501 also has a tube through which the drug solution flows, which may or may not be a pressure-resistant tube.

[0101] The third one-way valve V3 is attached to the first T-connector T1. The third one-way valve V3 allows flow toward the contrast agent syringe 604 and toward the first upstream tube 506a, while blocking flow toward the contrast agent chamber 601. With the third one-way valve V3 and the fifth one-way valve V5 (Figure 11), if the contrast agent is drawn upstream of the first baseline 508, i.e., toward the contrast agent syringe 604, the contrast agent will flow from the contrast agent line 501 toward the contrast agent syringe 604. If the contrast agent is discharged from upstream of the first baseline 508 toward downstream, i.e., toward the subject line 503, the contrast agent will not flow back into the contrast agent line 501.

[0102] The connector R, joined to the first T-connector T1, is connected to the tip of the contrast agent syringe 604 mounted on the injection device 608, or to a tube connected to the contrast agent syringe 604. The contrast agent line 501 is also connected to the first female connector F1 of the first baseline 508 via the first upstream tube 506a. The durability of this first upstream tube 506a can be improved by using a pressure-resistant braided tube.

[0103] As shown in Figure 13, a saline chamber 602 is connected to the saline line 502 of the drug solution circuit 2500. The saline line 502 has a spike needle 607 with a drip chamber. The saline flowing out of the saline chamber 602 drips into the drip chamber of the spike needle 607 and flows through the saline line 502. The saline line 502 also has a tube through which the drug solution flows, which may or may not be a pressure-resistant tube.

[0104] The fourth one-way valve V4 is connected to the second T-connector T2. The fourth one-way valve V4 allows flow toward the saline syringe 605 and toward the second upstream tube 506b, while blocking flow toward the saline chamber 602. Due to the fourth one-way valve V4 and the fifth one-way valve V5 (Figure 11), when saline is drawn toward the upstream side of the second baseline 509, i.e., toward the saline syringe 605, saline flows from the saline line 502 toward the saline syringe 605. When saline is discharged from the upstream side of the second baseline 509 toward the downstream side, i.e., toward the subject line 503, saline does not flow back into the saline line 502.

[0105] The connector R, joined to the second T-connector T2, is connected to the tip of the saline syringe 605 mounted on the injection device 608, or to a tube connected to the saline syringe 605. The saline line 502 is also connected to the second female connector F2 of the second baseline 509 via the second upstream tube 506b. The durability of this second upstream tube 506b can be improved by using a pressure-resistant braided tube.

[0106] Furthermore, in the contrast agent line 501, an air sensor 606 is positioned between the contrast agent chamber 601 and the spike needle 607 with a drip chamber. Similarly, in the saline line 502, an air sensor 606 is positioned between the saline chamber 602 and the spike needle 607 with a drip chamber. When these air sensors 606 detect the presence of air bubbles, they transmit a signal to the infusion device 608. Upon receiving the signal, the infusion device 608 performs at least one of the following actions: stop injecting the drug solution, stop aspirating the drug solution, or issue a notification (warning) that air has been detected.

[0107] [1st closing part] Next, the first closing mechanism 220a of the first closing section 200a will be described with reference to Figures 14 to 18. Figure 14 is a schematic perspective view showing the first closing mechanism 220a in the closed state. Figures 15A and 15B are schematic cross-sectional views showing the first closing mechanism 220a in the closed and open states, respectively, and show a longitudinal cross-section along the central axis of the internal flow path of the first closing mechanism 220a. Figure 16 is a schematic bottom view of the first pistons 222a1 and 222a2 in the closed state as seen from the first cap 252a. Figure 17 is a schematic perspective view showing the first piston 222a1 (first moving member) and the first piston 222a2 (second moving member) of the first closing mechanism 220a. Figure 18 is a schematic exploded view of the first piston 222a2.

[0108] The first closing mechanism 220a includes first heads 221a1, 221a2 which are pressed (pushed and pulled) by the presser of the first drive unit 230a, and first pistons 222a1, 222a2 (first and second moving members) which are substantially cylindrical and on which the first heads 221a1, 221a2 are formed. These first heads 221a1, 221a2 have a substantially cylindrical (disc-shaped) shape, but may have other shapes as long as they are easy to insert into the first drive unit 230a. Furthermore, the first closing mechanism 220a includes a first housing 224a which houses the first pistons 222a1, 222a2 so that they can slide in the sliding direction A indicated by the arrow in Figure 14. The first closing mechanism 220a also includes a pair of first conduit sections 223a. This pair of first conduit sections 223a are connected to the fifth one-way valve V5 and the air detection unit 2400, respectively (Figure 11). In Figures 14 and 15A,B, the right side corresponds to the injection device 608 side (upstream side), and the left side corresponds to the subject side (downstream side).

[0109] A tapered surface 254a is formed between the first heads 221a1, 221a2 and the bodies of the first pistons 222a1, 222a2. This allows a pair of first O-rings 227a (Figures 15A, B) to be easily fitted onto the first pistons 222a1, 222a2. Alternatively, the corners of the first heads 221a1, 221a2 may be chamfered, and the top and bottom surfaces of the first heads 221a1, 221a2 may be curved. This allows the first pistons 222a1, 222a2 to be easily inserted into the first housing 224a.

[0110] Furthermore, the first closing mechanism 220a includes a first housing 224a having a pair of holes for receiving the first pistons 222a1 and 222a2. The body of the first housing 224a has a first reinforcing rib 225a that extends around the outer circumference of the first housing 224a. The first reinforcing rib 225a has a first thin-walled portion 251a. This first thin-walled portion 251a is formed at a position corresponding to approximately the center of the first reinforcing rib 225a. The first housing 224a may also be made of a transparent material. This allows external observation of whether backflow is occurring inside the first housing 224a.

[0111] Furthermore, the first closing mechanism 220a has a first cap 252a positioned at the end of the first housing 224a in the sliding direction A of the first pistons 222a1, 222a2. That is, the first cap 252a is positioned on the opposite side from the first heads 221a1, 221a2 in the sliding direction A. This first cap 252a is bonded to the first mounting portion 253a of the first housing 224a with adhesive, but it may also be attached by methods such as ultrasonic fusion. Furthermore, a latch may be formed on one of the first cap 252a and the first mounting portion 253a, and a groove corresponding to the latch may be formed on the other to latch the two together. Also, the first cap 252a can be made of the same material as the first housing 224a. By providing such a first cap 252a, it is possible to prevent the first pistons 222a1, 222a2 from falling out.

[0112] As shown in Figure 15A, a first thickened portion 255a is formed on the inside of the first cap 252a. A first projection 256a is formed on the end of each of the first pistons 222a1 and 222a2 on the side facing the first cap 252a, so as to abut against this first thickened portion 255a. This first projection 256a abuts against the first thickened portion 255a and functions as an anti-rotation mechanism for the first pistons 222a1 and 222a2. In addition, a first stepped portion 257a is formed on the first cap 252a, which abuts against the end of the first mounting portion 253a. This first stepped portion 257a functions as a lid between the first mounting portion 253a and the first cap 252a. Therefore, it is possible to prevent the adhesive applied between the two from flowing into the first cap 252a. Furthermore, a groove may be formed at the end of the first mounting portion 253a to function as a liquid reservoir into which the adhesive flows.

[0113] As shown in Figure 16, a second thickened portion 258a is formed at the end of the first housing 224a on the first cap 252a side, at a position corresponding to the first thickened portion 255a of the first cap 252a. For convenience of explanation, Figure 16 also shows a horizontal cross-section perpendicular to the sliding direction A of the first cap 252a. The first protrusion 256a abuts against this second thickened portion 258a and functions as an anti-rotation device for the first pistons 222a1 and 222a2. Note that in Figure 15A, the second thickened portion 258a that overlaps with the first pistons 222a1 and 222a2 is shown with a dotted line.

[0114] The depth of the first cap 252a shown in Figure 15A, that is, the distance L1 from the end faces of the first pistons 222a1, 222a2 to the inner surface of the first cap 252a, is set to be longer than the travel distance L2 of the first pistons 222a1, 222a2 shown in Figure 15B. Therefore, even when the internal flow path is open, there is a small gap between the end faces of the first pistons 222a1, 222a2 and the inner surface of the first cap 252a. In addition, the length of the first projection 256a in the sliding direction A is also set to be longer than the travel distance L2.

[0115] The first piston 222a1, positioned upstream, is equipped with a first flow path 226a1 having a long, approximately elliptical cross-section in the sliding direction A. On the other hand, the first piston 222a2, positioned downstream, is equipped with a first flow path 226a2 having a short, approximately circular cross-section in the sliding direction A. Therefore, in the sliding direction A, the first flow path 226a1 of the first piston 222a1 is larger than the first flow path 226a2 of the first piston 222a2. Furthermore, the upper end positions of the first flow paths 226a1 and 226a2 are set so that they are the same distance from the corresponding opening in the first conduit section 223a. As a result, when both pistons are pressed simultaneously and at the same speed, when the upper end of the first flow path 226a1 faces the opening in the first conduit section 223a, the upper end of the first flow path 226a2 also faces the opening in the first conduit section 223a. Furthermore, the upper end positions of the first channels 226a1 and 226a2 are set so that they are the same distance from the hole 228.

[0116] A hole 228 is formed approximately in the center of the first housing 224a, which, together with the first flow paths 226a1 and 226a2, constitutes the internal flow path of the first closing section 200a. That is, the hole 228 is formed between a pair of holes that receive the first pistons 222a1 and 222a2. When the flow path is open, both ends of this hole 228 face the first flow paths 226a1 and 226a2, respectively. This opens the internal flow path of the first closing section 200a.

[0117] When opening the internal passages, the first pistons 222a1 and 222a2 are simultaneously moved toward the first cap 252a (downward in Figure 15A). Then, as shown in Figure 15B, the first passage 226a1 of the first piston 222a1 and the first passage 226a2 of the first piston 222a2 are brought toward the opening in the first conduit section 223a. At this point, when the lower end of the first passage 226a1 faces the opening in the first conduit section 223a, the side of the first piston 222a2 faces the opening in the first conduit section 223a. Therefore, the upstream first passage 226a1 is opened, but the downstream first passage 226a2 is not opened. Subsequently, the first pistons 222a1 and 222a2 move further, and the upper end of the first passage 226a2 faces the opening in the first conduit section 223a. As a result, the pair of first conduit sections 223a communicate with the liquid through the first flow paths 226a1, 226a2 and the hole 228, and the internal flow path is opened.

[0118] On the other hand, when the first pistons 222a1 and 222a2 are moved in opposite directions (upward in Figure 15B), as shown in Figure 15A, the sides of the first pistons 222a1 and 222a2 face the openings in the first conduit section 223a, respectively, and the internal flow paths are closed. At this time, when the lower end of the first flow path 226a2 moves away from the opening in the first conduit section 223a (its side faces the opening), the first flow path 226a1 is still facing the opening in the first conduit section 223a. Therefore, the first flow path 226a2 is closed, but the first flow path 226a1 is not. Subsequently, the first flow path 226a1 moves away from the opening in the first conduit section 223a (its side faces the opening). As a result, both the first flow paths 226a1 and 226a2 are closed.

[0119] When opening the internal flow path, the first flow path 226a1 of the first piston 222a1 is opened first, followed by the first flow path 226a2 of the first piston 222a2. This prevents backflow from reaching the first piston 222a1, as the blood is pushed towards the subject by the drug solution when the flow path is opened. Furthermore, when the flow path is closed, the first flow path 226a1 of the first piston 222a1 is isolated from the opening in the first conduit section 223a, so backflow does not reach the first flow path 226a1. As a result, backflow upstream of the first closure section 200a can be prevented more reliably.

[0120] The injector 608, which controls the first drive unit 230a and the second drive unit 230b, may open the internal flow path of the first closure mechanism 220a when the pressure in the line upstream of the first closure mechanism 220a is higher than the pressure in the line downstream of the first closure mechanism 220a. For example, the injector 608 may open the internal flow path after a predetermined time (for example, 1 second) has elapsed since the start of drug injection. In this case, the injector 608 advances at least one of the plungers of the contrast agent syringe 604 and the saline syringe 605 to increase the pressure in the line upstream of the first piston 222a1.

[0121] Subsequently, the injection device 608 moves the first pistons 222a1 and 222a2 toward the first cap 252a to open the internal passage. This opens the first passage 226a1 of the first piston 222a1 with the pressure in the line upstream of the first piston 222a1 higher than the pressure in the line downstream of the first piston 222a2. Therefore, even if backflow blood has reached the vicinity of the first piston 222a2 when the internal passage is opened, it is possible to prevent the blood from moving toward the first piston 222a1. When the internal passage is opened, the blood is pushed by the drug solution and flows downstream of the first closing mechanism 220a.

[0122] Furthermore, the injection device 608 may open its internal passage when the pressure in the line upstream of the first piston 222a1 or the injection pressure of the chemical solution reaches a predetermined value. For example, the injection device 608 is equipped with a detection unit that detects the pressure in the line or the injection pressure of the chemical solution, and obtains the pressure value from the detection unit. Then, the injection device 608 opens its internal passage when the pressure value reaches a predetermined value. In this case, the injection device 608 may open its internal passage at the same time as the injection of the chemical solution begins.

[0123] The first closing mechanism 220a has a pair of first O-rings 227a corresponding to the first pistons 222a1 and 222a2, respectively. The first flow paths 226a1 and 226a2 are each formed between the pair of first O-rings 227a. These first O-rings 227a are fitted into annular recesses formed on the circumferential surfaces of the first pistons 222a1 and 222a2. The first O-rings 227a prevent fluid leakage from between the sides of the first pistons 222a1 and 222a2 and the inner surface of the first housing 224a. Furthermore, to more reliably prevent fluid leakage, the first closing mechanism 220a has a first sleeve 240a positioned between the pair of first O-rings 227a and sealing around the first flow path 226a2.

[0124] As shown in Figure 15A, the first corners 259a on the inside of the first cap 252a are all chamfered and curved. This prevents the first O-ring 227a from coming into contact with the first corners 259a and getting damaged during the assembly of the first closing mechanism 220a. Specifically, when assembling the first closing mechanism 220a, first, a pair of first O-rings 227a are press-fitted into the first piston 222a1 and the first piston 222a2, which have the first sleeve 240a inserted, from the first head 221a1 and 221a2 side. Next, the first pistons 222a1 and 222a2 are inserted into the first housing 224a from the first mounting portion 253a side. After that, the first cap 252a is bonded to the first mounting portion 253a. Here, when inserting the first pistons 222a1 and 222a2, there is a possibility that the first O-ring 227a may come into contact with the first corner 259a. However, because a curved surface is formed on the first corner 259a, damage to the first O-ring 227a can be suppressed.

[0125] As shown in Figure 17, the substantially cylindrical first sleeve 240a is fitted onto the first piston 222a2. This first sleeve 240a is made of silicone and can be formed by insert molding. The first sleeve 240a also has a pair of holes 241 formed therein so as to expose the inlet and outlet of the first flow path 226a2. These holes 241 have an inner diameter that is slightly larger than the inner diameter of the first flow path 226a2. As a result of shrinking during press-fitting, the pair of holes 241 become approximately the same size as the first flow path 226a2.

[0126] Furthermore, a substantially rectangular recess 242 is formed in the first sleeve 240a. This recess 242 does not come into contact with the first housing 224a. This reduces the frictional resistance between the first piston 222a2 and the first sleeve 240a. In addition, protrusions 246 are formed between the recess 242 and the pair of first O-rings 227a. The protrusions 246 project outward from the recess 242 and extend along the first flow path 226a2 around the first piston 222a2. This recess 242 suppresses deformation of the first sleeve 240a when the first piston 222a2 slides. This prevents the pair of holes 241 from deforming and getting caught in the first flow path 226a2.

[0127] The portion of the first sleeve 240a surrounding the pair of holes 241 is thicker than the recess 242 and contacts the inner surface of the first housing 224a. As shown in Figure 18, the first piston 222a2 has a thin-walled portion 243 at a position corresponding to the thick-walled portion. On the other hand, the first piston 222a2 has a protrusion 244 at a position corresponding to the recess 242. The first sleeve 240a has an inner shape complementary to the thin-walled portion 243 and the protrusion 244. The first sleeve 240a is fitted into the thin-walled portion 243 and the protrusion 244. This prevents the first sleeve 240a from being displaced when the first piston 222a2 slides.

[0128] [Second closing part] Next, the second closing mechanism 220b of the second closing section 200b will be described with reference to Figures 19 and 20A,B. This second closing section 200b differs from the first closing section 200a in that it has one second piston 222b (third moving member). Note that the second piston 222b has the same configuration as the first piston 222a2, so a detailed explanation will be omitted. Alternatively, the second piston 222b may be configured in the same way as the first piston 222a1.

[0129] Figure 19 is a schematic perspective view showing the second closure mechanism 220b in a closed state. Figures 20A and 20B are schematic cross-sectional views showing the second closure mechanism 220b in a closed and open state, respectively, and show a longitudinal cross-section along the central axis of the internal flow path of the second closure mechanism 220b. The second closure mechanism 220b is connected to the second tube pair 110b, but for the sake of clarity, the second tube pair 110b is not shown in Figures 19 and 20A and 20B.

[0130] The second closing mechanism 220b, which closes the internal flow path, comprises a second head 221b that is pressed (pushed and pulled) by the presser of the second drive unit 230b, and a substantially cylindrical second piston 222b on which the second head 221b is formed. The second closing mechanism 220b also comprises a second housing 224b that slidably accommodates the second piston 222b. Furthermore, the second closing mechanism 220b comprises a pair of second conduit sections 223b to which the second tube pair 110b is joined.

[0131] A tapered surface 254b is formed between the second head 221b and the body of the second piston 222b. This allows a pair of second O-rings 227b (Figures 20A, B) to be easily fitted onto the second piston 222b. The second housing 224b has a hole for receiving the second piston 222b. The second housing 224b has a second reinforcing rib 225b that extends around the outer circumference of the second housing 224b. The second reinforcing rib 225b has a second thin-walled portion 251b formed approximately in the center.

[0132] Furthermore, the second closing mechanism 220b has a second cap 252b positioned at the end of the second housing 224b in the sliding direction A of the second piston 222b. That is, the second cap 252b is positioned on the opposite side from the second head 221b in the sliding direction A. This second cap 252b is bonded to the second mounting portion 253b of the second housing 224b. In addition, a projection 250b1 is formed on the second mounting portion 253b, which functions as an anti-rotation mechanism for the second cap 252b. The second cap 252b has a recess 250b2 formed therein, which has a shape complementary to the projection 250b1, and the projection 250b1 engages with the recess 250b2.

[0133] As shown in Figure 20A, a third thickened portion 255b is formed on the inside of the second cap 252b. A second projection 256b is formed on the end of the second piston 222b on the second cap 252b side, projecting laterally so as to abut against this third thickened portion 255b. The second projection 256b abuts against the third thickened portion 255b and functions as an anti-rotation mechanism for the second piston 222b. In addition, a second stepped portion 257b is formed on the second cap 252b, which abuts against the end of the second mounting portion 253b. This second stepped portion 257b functions as a cover between the second mounting portion 253b and the second cap 252b.

[0134] At the end of the second housing 224b on the second cap 252b side, a fourth thickened portion 258b is formed at a position corresponding to the third thickened portion 255b of the second cap 252b. The second protrusion 256b abuts against this fourth thickened portion 258b and functions as an anti-rotation mechanism for the second piston 222b. In Figure 20A, the fourth thickened portion 258b that overlaps with the second piston 222b is shown with a dotted line.

[0135] In the second closing mechanism 220b, the depth of the second cap 252b, that is, the distance from the end face of the second piston 222b to the inner surface of the second cap 252b, is set to be longer than the travel distance of the second piston 222b. Therefore, even when the internal flow path is open, there is a small gap between the end face of the second piston 222b and the inner surface of the second cap 252b. In addition, the length of the second projection 256b in the sliding direction A is also set to be longer than the travel distance of the second piston 222b.

[0136] The second piston 222b is equipped with a second flow path 226b having a short, substantially circular cross-section in the sliding direction A. When opening the internal flow path (second flow path 226b), the second piston 222b is moved toward the second cap 252b (downward in Figure 20A). Then, as shown in Figure 20B, the second flow path 226b of the second piston 222b is brought into contact with the opening in the second conduit section 223b. As a result, the pair of second conduit sections 223b communicate with the liquid through the second flow path 226b, and the internal flow path is opened. On the other hand, when the second piston 222b is moved in the opposite direction (upward in Figure 20B), as shown in Figure 20A, the side of the second piston 222b faces the opening in the second conduit section 223b, and the internal flow path is closed.

[0137] The second closing mechanism 220b has a pair of second O-rings 227b corresponding to the second piston 222b. The second flow path 226b is formed between the pair of second O-rings 227b. These second O-rings 227b are fitted into annular recesses formed on the circumferential surface of the second piston 222b. The second closing mechanism 220b also has a second sleeve 240b positioned between the pair of second O-rings 227b and sealing around the second flow path 226b of the second piston 222b. Furthermore, the second corners 259b on the inner surface of the second cap 252b are all chamfered to form curved surfaces. This prevents the second O-rings 227b from coming into contact with and being damaged by the second corners 259b during the assembly of the second closing mechanism 220b.

[0138] [Connector with rotator] The rotator-equipped connector R will be described with reference to Figures 21 and 22. Figure 21 is a schematic exploded perspective view of the connector R, and Figure 22 is a schematic cross-sectional view of the connector R along its longitudinal direction after the syringe has been connected.

[0139] As shown in Figure 21, the connector R has a rotator 700 with a through hole 701 and a tip portion 800 attached to the end of the through hole 701 (the end on the subject side). The tip of a syringe or a tube connected to a syringe is detachably connected to the end of the through hole 701 (the end on the injection device 608 side). Multiple ribs 702 are formed on the side of the rotator 700. The tip portion 800 has a side surface, an inclined claw 802 formed on the side surface, and an annular projection 803 formed on the side surface spaced apart from the inclined claw 802. This annular projection 803 is formed on the end side of the tip portion 800, closer to the tip than the inclined claw 802. Furthermore, the tip portion 800 has a through hole 801 through which the drug solution flows.

[0140] The inclined claws 802 protrude from the side of the tip portion 800 to form a gradually increasing step, and have an inclined surface that slopes relative to the side. Four of these inclined claws 802 are formed at equal intervals around the tip portion 800, but there may be three or fewer or four or more inclined claws 802. The tip portion 800 also has an annular projection 803 that protrudes from the side of the tip portion 800. The annular projection 803 protrudes from the side higher than the inclined claws 802, and there is a gap between the annular projection 803 and the inclined claws 802. In the assembled connector R, the rotator 700 is rotatable relative to the tip portion 800.

[0141] As shown in Figure 22, the rotator 700 has an annular engaging claw 703 that protrudes within the through hole 701. This engaging claw 703 is formed at the tip of the rotator 700. When connecting the connector R to the syringe, the tip of the syringe is inserted into the end of the through hole 701 and the rotator 700 is rotated. This causes the screw groove 704 formed on the inner surface of the rotator 700 to screw into the tip of the syringe. At this time, the engaging claw 703 slides on the inclined surface of the inclined claw 802 of the tip portion 800 and engages with the gap between the inclined claw 802 and the annular projection 803. The operator can feel a click when the engaging claw 703 engages, thus confirming that the connection is complete.

[0142] After screwing, the engaging claw 703 contacts the inclined claw 802, restricting the movement of the rotator 700 toward the tip. By providing such a connector R, the operator can connect the syringe to the drug solution circuit 2500 without touching the tip of the syringe. Note that only one inclined claw 802 may be formed around the entire circumference of the tip portion 800. However, since the contact area is reduced compared to when only one is formed around the entire circumference, forming four inclined claws 802 can reduce resistance during screwing.

[0143] Figure 23 shows the liquid reservoir cap 900 connected to the third male connector M3, and Figure 24 is a schematic perspective view of the liquid reservoir cap 900. This liquid reservoir cap 900 is connected to the third male connector M3 during air bleeding. As a result, the drug solution that fills the drug solution circuit and is discharged from the third male connector M3 is collected in the liquid reservoir cap 900, thereby suppressing leakage of the drug solution. After air bleeding, the liquid reservoir cap 900 is removed from the third male connector M3, and the catheter is connected to the third male connector M3.

[0144] As shown in Figure 24, the liquid reservoir cap 900 has a flat bottom surface 901, a circumferential surface 902 consisting of an arc-shaped curved surface, and a connection port 903 protruding from the circumferential surface. The flat bottom surface 901 allows the liquid reservoir cap 900 removed from the third male connector M3 to be placed on it. This prevents the internal chemical solution from leaking out through the connection port 903. This liquid reservoir cap 900 is made of polypropylene and can be manufactured by blow molding.

[0145] The male luer of the third male connector M3 is inserted into the connection port 903. Four planes 904 are formed at equal intervals inside the connection port 903, and the inner diameter of the connection port 903 is larger than the outer diameter of the male luer. Therefore, when the male luer is inserted, only a portion of the planes 904 of the connection port 903 contacts the outer surface of the male luer. This creates a gap between the male luer and the connection port 903 around the planes 904. This gap functions as an escape route for air inside the liquid reservoir cap 900. In Figure 24, the cross-sectional shape of the connection port 903 is rectangular, and the corners of the connection port 903 are curved. Alternatively, the connection port 903 may have a polygonal (e.g., square) cross-sectional shape.

[0146] When aspirating contrast agent or saline solution, the liquid reservoir cap 900 may be connected to the first male connector M1 and the second male connector M2 via a one-way valve tube. This prevents leakage of the drug solution from the tip of the one-way valve tube after aspiration. The one-way valve tube and liquid reservoir cap are removed from the first male connector M1 and the second male connector M2 after aspirating the drug solution. Subsequently, the first downstream tube 507a and the second downstream tube 507b are connected to the first male connector M1 and the second male connector M2, respectively.

[0147] The drug solution circuit 2500 of the second embodiment described above can more reliably prevent blood backflow and can be more easily attached to the injection device 608 due to the smaller number of parts. Furthermore, in the drug solution circuit 2500 of the second embodiment, a one-way valve is not placed in the line between the air sensor 606 of the first closure section 200a and the injection device 608. Therefore, the air present in the syringe is prevented from being subdivided by the one-way valve, thereby improving the accuracy of air detection.

[0148] [Third Embodiment] Figure 25 is a schematic diagram of the chemical solution circuit 3500 according to the third embodiment. In describing the third embodiment, the differences from the first and second embodiments will be explained, and the same reference numerals will be used for components described in the first and second embodiments, and their descriptions will be omitted. Unless otherwise specified, components with the same reference numerals will perform substantially the same operation and function, and their effects will also be substantially the same.

[0149] In the third embodiment, a clamp CL (for example, a closing device described in Japanese Patent Application Publication No. 2017-143851) for closing the flow path is placed on the second downstream tube 507b of the second baseline 509. This clamp CL comprises a support portion that supports the second downstream tube 507b and a projection portion that protrudes toward the support portion. The projection portion is pressed toward the support portion by a pressing member (not shown). A manual clamp may be used instead of the electric clamp CL, or a second closing mechanism 220b may be connected.

[0150] The internal flow path of the second downstream tube 507b can be closed by clamping and crushing the second downstream tube 507b with the clamp CL. For example, the infusion device 608 controls the clamp CL so that the flow path is automatically closed except when injecting saline solution (including priming). Alternatively, the infusion device 608 may control the open clamp CL to close the flow path when aspirating contrast agent or saline solution and when injecting contrast agent.

[0151] In the second embodiment, when aspirating contrast agent or saline solution, a tube with a one-way valve is connected to the first male connector M1 and the second male connector M2. This prevents saline solution from flowing into the first baseline 508 and contrast agent from flowing into the second baseline 509 when aspirating the drug solution.

[0152] On the other hand, in the third embodiment, the internal flow path of the second downstream tube 507b is closed by the clamp CL, so the inflow of the drug solution during drug solution aspiration can be prevented even without connecting a tube with a one-way valve. Therefore, the drug solution circuit 3500 can be manufactured at low cost. In addition, when injecting contrast agent, the internal flow path of the second downstream tube 507b is closed by the clamp CL. This prevents the contrast agent from flowing into the second baseline 509.

[0153] The drug solution circuit 3500 of the third embodiment described above can more reliably prevent blood backflow and, due to the smaller number of parts, can be more easily attached to the injection device 608. Furthermore, in the drug solution circuit 3500 of the third embodiment, a one-way valve is not placed in the line between the air detection unit 2400 and the injection device 608. Therefore, even if air is present in the syringe, the one-way valve prevents the air from being subdivided, thereby improving the accuracy of air detection.

[0154] Although the present invention has been described above with reference to the embodiments described, the present invention is not limited to the embodiments described above. Inventions modified within the scope that does not contradict the present invention, and inventions equivalent to the present invention are also included in the present invention. Furthermore, each embodiment and each variation can be appropriately combined within the scope that does not contradict the present invention.

[0155] For example, the syringe mounted on the injection device 608 may be either a syringe filled with drug solution or an empty syringe. Syringes filled with drug solution include pre-filled syringes, syringes obtained by the operator filling an empty syringe with drug solution using an aspirator or filler, and syringes obtained by the operator manually filling an empty syringe with drug solution. The two syringes mounted on the injection device 608 may be filled with contrast agents of different concentrations. At least one of the two syringes may be filled with a mixture of contrast agent and physiological saline solution. Furthermore, the syringe may be equipped with a data carrier such as an RFID (Radio Frequency Identifier) ​​or a barcode. Information about the filled drug solution is recorded on this data carrier. The injection device 608 can read the information recorded on the data carrier and control the injection pressure of the drug solution.

[0156] Furthermore, the injection device 608 can be connected to the imaging device by wire or wireless connection. During drug injection and image acquisition, various data are transmitted and received between the imaging device and the injection device 608. In this case, for example, imaging conditions may be set or displayed in the injection device 608, or injection conditions may be set or displayed in the imaging device. Examples of such imaging devices include various medical imaging devices such as MRI (Magnetic Resonance Imaging) devices, CT (Computed Tomography) devices, angiography devices, PET (Positron Emission Tomography) devices, SPECT (Single Photon Emission Computed Tomography) devices, CT angiography devices, MR angiography devices, ultrasound diagnostic devices, and vascular imaging devices.

[0157] Furthermore, the injection device 608 can also transmit and store information regarding the injection results (injection history) via the network to external storage devices such as RIS (Radiology Information System), PACS (Picture Archiving and Communication System), and HIS (Hospital Information System).

[0158] Furthermore, the injection device 608 may be wired or wirelessly connected to remote control devices such as a foot switch and a hand switch. The operator can operate the injection device 608 by operating the remote control device instead of the control unit 609. For example, when the operator presses the start button on the remote control device, the control unit of the injection device 608 transmits a drug injection command to the injection device 608. Furthermore, the operator may change the injection speed by operating the remote control device. Also, the first closure unit 200a and the second closure unit 200b may be integrally provided within a single closure unit. Also, the air sensor 606 may be an optical (e.g., infrared) sensor. Furthermore, the first housing or the second housing may have other external shapes as long as they are easy to insert into the first drive unit or the second drive unit.

[0159] Some or all of the above embodiments may also be described as follows, but are not limited to the following:

[0160] (Note 1) A method for controlling the closing mechanism of a chemical solution circuit, A control method for opening the internal flow path of the closing mechanism while the pressure in the line upstream of the closing mechanism is higher than the pressure in the line downstream of the closing mechanism.

[0161] (Note 2) The control method described in Appendix 1, wherein the internal flow path is opened after a predetermined time has elapsed since the start of injection of the drug solution.

[0162] (Note 3) The closing mechanism comprises a first movable member and a second movable member, each having a flow path, and a housing that slidably accommodates the first movable member and the second movable member. The control method according to Appendix 1 or 2, wherein the flow path of the first moving member is opened while the pressure in the line upstream of the first moving member is higher than the pressure in the line downstream of the second moving member.

[0163] (Note 4) A tip portion having a side surface, an inclined claw formed on the side surface, and an annular projection formed on the side surface spaced apart from the inclined claw, The rotator is rotatable relative to the aforementioned tip and has a through hole and an engaging claw protruding from within the through hole, The connector wherein the annular projection is formed on the distal end side of the tip portion, relative to the inclined claw.

[0164] This application claims priority from Japanese Patent Application No. 2017-062582, filed on 28 March 2017, and incorporates its entire contents as part of this application. [Explanation of Symbols]

[0165] 100a: First closing section, 120a: First closing mechanism, 122a1: First moving member, 122a2: Second moving member, 124a: First housing, 130a: Drive unit, 200a: First closing section, 221a1: First head, 221a2: First head, 220a: First closing mechanism, 222a1: First moving member, 222a2: Second moving member, 224a: First housing, 230a: First drive unit, 500: Drug solution circuit, 503: Subject line, 508: First baseline, 509: Second baseline, 2500: Drug solution circuit, 3500: Drug solution circuit

Claims

1. A closing mechanism for closing the internal flow path of a chemical solution circuit, A sliding member having a flow path, A housing that slidably accommodates the aforementioned sliding member, It is equipped with, A closing mechanism wherein the sliding member has a recess formed on its outer circumference between the inlet and outlet of the flow path.

2. The closing mechanism according to claim 1, wherein the sliding member comprises a piston and a sleeve fitted onto the piston.

3. The closing mechanism according to claim 2, wherein the recess is formed in the sleeve.

4. It also includes a pair of O-rings, The closing mechanism according to any one of claims 1 to 3, wherein the recess is formed between the pair of O-rings.

5. A closing mechanism for closing the internal flow path of a chemical solution circuit, A sliding member having a flow path, A housing that slidably accommodates the aforementioned sliding member, It is equipped with, The sliding member has a hole formed in it that corresponds to the flow path. The sliding member is a closing mechanism in which the area around the hole is made thicker.

6. The sliding member comprises a piston and a sleeve fitted onto the piston. The closing mechanism according to claim 5, wherein the sleeve is configured to be thicker around the hole.

7. The first baseline through which the first drug solution flows, The second baseline through which the second medication flows, A subject line connected to the first baseline and the second baseline, A closing mechanism that closes the internal flow path of the chemical solution circuit, Equipped with, The closing mechanism comprises a sliding member having a flow path and a housing that slidably accommodates the sliding member. The sliding member has a recess formed so as not to contact the housing, The recess is a chemical solution circuit formed on the outer circumference of the sliding member between the inlet and outlet of the flow path.

8. An injection device for injecting the first drug solution and the second drug solution, The first baseline through which the first drug solution flows, The second baseline through which the second drug solution flows, A subject line connected to the first baseline and the second baseline, A closing mechanism that closes the internal flow path of the chemical solution circuit, Equipped with, The closing mechanism comprises a sliding member having a flow path and a housing that slidably accommodates the sliding member. The sliding member has a recess formed so as not to contact the housing, The recess is formed on the outer circumference of the sliding member between the inlet and outlet of the flow path in the injection system.

Images