Medical reservoir and cerebrospinal fluid circulation circuit

Abstract

A purpose of the present invention is to provide a medical reservoir and a cerebrospinal fluid circulation circuit with which it is possible to simplify the structure while suppressing fluctuations in intracranial pressure when circulation of cerebrospinal fluid is executed. A medical reservoir 3 includes: a first chamber 31 having an inflow port 311 for introducing a fluid from the outside to the inside; a second chamber 32 having a discharge port 321 for discharging the fluid from the inside to the outside; at least one flow path 331 provided between the first chamber 31 and the second chamber 32 and connecting the first chamber 31 and the second chamber 32; and a one-way valve 34 provided in the flow path 331 and allowing the movement of the fluid from the first chamber 31 toward the second chamber 32 while preventing the movement of the fluid from the second chamber 32 toward the first chamber 31. The passage through which the fluid can move between the first chamber 31 and the second chamber 32 is only the flow path 331 provided with the one-way valve 34.

Description

Medical Reservoir and Cerebrospinal Fluid Circulation Circuit

[0001] The present invention relates to a medical reservoir and a cerebrospinal fluid circulation circuit for use in treating brain diseases.

[0002] When a brain disease such as cerebral infarction occurs, blood flow that supplies oxygen to brain cells is blocked, which may cause damage to brain cells. Therefore, when cerebral infarction occurs, early reperfusion of blood flow is necessary. As one treatment for cerebral infarction, it has been proposed to inject a hyperoxygenated solution such as oxygenated cerebrospinal fluid into the body cavity where the patient's cerebrospinal fluid exists, to directly supply oxygen to oxygen-deficient brain cells.

[0003] Patent Document 1 discloses a brain disease treatment device used for treating brain diseases, and a brain disease treatment system including the brain disease treatment device. The brain disease treatment system described in Patent Document 1 comprises a spinal subarachnoid space catheter system, a pump system, and an oxygenation mechanism. The brain disease treatment device is used in the spinal subarachnoid space catheter system.

[0004] Examples of pumps used for the pump system of the brain disease treatment system include centrifugal pumps. Further, examples of the oxygenation mechanism of the brain disease treatment system include hollow fiber artificial lungs for adding oxygen to blood. However, when a centrifugal pump and a hollow fiber artificial lung are used, the brain disease treatment system becomes large-scale as a whole, which increases medical cost, so there remains room for improvement in this respect.

[0005] Further, when circulation of cerebrospinal fluid is performed, in which cerebrospinal fluid is drained out of the body cavity and a hyperoxygenated solution is injected into the body cavity, fluctuations in intracranial pressure (ICP: Intracranial Pressure) may cause damage to the brain. Therefore, when cerebrospinal fluid circulation is performed, it is required to suppress fluctuations in intracranial pressure within a predetermined range.

[0006] International Publication No. WO 2023 / 181979

[0007] The present invention has been made in view of the above circumstances, and aims to provide a medical reservoir and a cerebrospinal fluid circulation circuit that can simplify the structure while suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0008] The present invention relates to a medical reservoir comprising: (1) a first chamber having an inlet for introducing fluid from the outside to the inside; a second chamber having an outlet for discharging the fluid from the inside to the outside; at least one flow path provided between the first chamber and the second chamber and connecting the first chamber and the second chamber; and a one-way valve provided in the flow path that allows the movement of the fluid from the first chamber to the second chamber while preventing the movement of the fluid from the second chamber to the first chamber, wherein the only passage through which the fluid can move between the first chamber and the second chamber is the flow path provided with the one-way valve.

[0009] According to the medical reservoir described in (1) above, fluid is introduced into the first chamber from outside the first chamber through the inlet of the first chamber. The fluid contained in the first chamber is guided to the second chamber through a passage connecting the first and second chambers. The fluid contained in the second chamber is discharged from inside the second chamber through the outlet of the second chamber to the outside of the second chamber. Here, a one-way valve is provided in the passage. The one-way valve allows the fluid to move from the first chamber to the second chamber, while preventing the fluid from moving from the second chamber to the first chamber. Furthermore, the only passage through which the fluid can move between the first and second chambers is the passage where the one-way valve is provided.

[0010] Thus, since the first and second chambers are separated from each other by a one-way valve, even if the pressure inside the second chamber fluctuates, the pressure fluctuations inside the second chamber can be prevented from affecting the pressure inside the first chamber. This prevents phenomena such as obstruction of fluid introduction into the first chamber or backflow of fluid. Furthermore, even when the first chamber is connected to a cavity in the body containing cerebrospinal fluid via, for example, a conduit and drainage catheter, the medical reservoir according to the present invention can suppress fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed. In addition, the first chamber can function as a reservoir for temporarily storing cerebrospinal fluid that has been drained outside the body. Therefore, the medical reservoir according to the present invention can be simplified in structure.

[0011] (2) The medical reservoir described in (1) above preferably further comprises a gas introduction section provided in at least the second chamber for introducing the gas supplied from the outside into the fluid contained in the second chamber.

[0012] According to the medical reservoir described in (2) above, the gas introduction section is provided in at least the second chamber and introduces gas supplied from the outside into the fluid contained in the second chamber. As a result, the gas introduction section can perform bubbling in the second chamber, for example, to produce oxygenated cerebrospinal fluid as a highly oxygenated solution. Thus, the medical reservoir according to the present invention can simplify its structure by combining a first chamber that functions as a reservoir and a second chamber that functions as a simple oxygenation mechanism using bubbling, while suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0013] (3) The medical reservoir described in (1) above preferably further comprises a pressure release section provided in the second chamber for maintaining the internal pressure of the second chamber below a predetermined pressure.

[0014] According to the medical reservoir described in (3) above, the pressure release section is located in the second chamber, and the pressure inside the second chamber is kept below a predetermined pressure. Therefore, even if the pressure inside the second chamber rises due to bubbling or other operations, the pressure release section releases the pressure inside the second chamber to the outside and keeps it below a predetermined pressure, thereby more reliably suppressing the effect of pressure fluctuations inside the second chamber on the pressure inside the first chamber.

[0015] (4) In the medical reservoir described in (1) above, it is preferable that at least one of the first chamber and the second chamber has an inlet for introducing a therapeutic fluid from the outside to the inside.

[0016] According to the medical reservoir described in (4) above, for example, the operator can inject therapeutic fluid into the medical reservoir through an inlet provided in at least one of the first and second chambers before performing cerebrospinal fluid circulation.

[0017] (5) In the medical reservoir described in (1) above, it is preferable that the one-way valve is opened at a lower pressure, for example, a pressure of 5 mmHg or less.

[0018] According to the medical reservoir described in (5) above, the one-way valve opens at a low pressure, for example, 5 mmHg or less, thus more reliably allowing the fluid to move from the first chamber to the second chamber even if the pressure inside the second chamber fluctuates.

[0019] (6) In the medical reservoir described in (1) above, the one-way valve is preferably an umbrella valve or a duckbill valve.

[0020] According to the medical reservoir described in (6) above, the one-way valve can be opened at a relatively low pressure, and a sufficient flow path can be secured when the valve body is opened.

[0021] (7) The present invention is a cerebrospinal fluid circulation circuit characterized by comprising the medical reservoir described in (1) above; a first conduit having a first end that can be inserted into a containment cavity in a living body where cerebrospinal fluid is present and can be connected to a drainage catheter for draining the cerebrospinal fluid outside the living body, and a second end that is connected to the inlet of the medical reservoir; and a second conduit having a third end that is connected to the outlet of the medical reservoir and a fourth end that can be inserted into the containment cavity and can be connected to an injection catheter for injecting the fluid into the containment cavity.

[0022] According to the cerebrospinal fluid circulation circuit described in (7) above, the drainage catheter is insertable into a cavity within the body where cerebrospinal fluid is present, and drains the cerebrospinal fluid outside the body. The fluid, guided through the first end connected to the drainage catheter into the first conduit, passes through the inlet connected to the second end and is introduced into the first chamber. The fluid contained in the first chamber is guided to the second chamber through a flow path connecting the first and second chambers. Here, a one-way valve is provided in the flow path. The one-way valve allows the fluid to move from the first chamber to the second chamber, while preventing the fluid from moving from the second chamber to the first chamber. Furthermore, the only passage through which the fluid can move between the first and second chambers is the flow path with the one-way valve. The fluid contained in the second chamber is drained through the third end connected to the outlet into the second conduit and guided into an infusion catheter connected to the fourth end. The infusion catheter is insertable into the cavity and injects the fluid into the cavity.

[0023] Thus, since the first chamber and the second chamber are separated from each other by a one-way valve, even if the pressure inside the second chamber fluctuates, the pressure fluctuations inside the second chamber can be suppressed from affecting the pressure inside the first chamber. As a result, even if the first chamber is connected to a containment cavity in the body where cerebrospinal fluid exists via the first conduit and drainage catheter, the cerebrospinal fluid circulation circuit according to the present invention can suppress fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed. Furthermore, the first chamber can function as a reservoir for temporarily storing cerebrospinal fluid that has been drained outside the body. Therefore, the structure of the cerebrospinal fluid circulation circuit according to the present invention can be simplified.

[0024] (8) The cerebrospinal fluid circulation circuit described in (7) above preferably further comprises a connector that can connect the first end to the drainage catheter and can accept the infusion catheter.

[0025] According to the cerebrospinal fluid circulation circuit described in (8) above, the connector can connect the first end of the first conduit to the drainage catheter and can also receive the infusion catheter. This allows for a simplified structure of the cerebrospinal fluid circulation circuit according to the present invention.

[0026] (9) In the cerebrospinal fluid circulation circuit described in (7) above, it is preferable that the second conduit has a pump attachment portion connected to a fluid delivery pump that delivers the fluid into the living body.

[0027] According to the cerebrospinal fluid circulation circuit described in (9) above, the surgeon can easily incorporate the fluid delivery pump into the cerebrospinal fluid circulation circuit by attaching the fluid delivery pump to the pump attachment part of the second conduit.

[0028] (10) The cerebrospinal fluid circulation circuit described in (9) above preferably further comprises a pressure measuring unit for measuring the pressure inside the second conduit between the pump mounting unit and the fourth end.

[0029] According to the cerebrospinal fluid circulation circuit described in (10) above, the pressure measuring unit measures the pressure inside the second conduit between the pump attachment unit and the fourth end, thereby indirectly inferring fluctuations in intracranial pressure from the pressure of the fluid delivered from the fluid delivery pump, and thus more reliably suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0030] (11) The present invention is a cerebrospinal fluid circulation circuit characterized by comprising: a medical reservoir described in (1) above for performing therapeutic treatment on cerebrospinal fluid; an outlet catheter that can be inserted into a containment cavity in a living body where the cerebrospinal fluid is present and for discharging the cerebrospinal fluid outside the living body; a first conduit having a first end connectable to the outlet catheter and a second end connectable to the inlet of the medical reservoir; an injection catheter that can be inserted into the containment cavity and for injecting the fluid into the containment cavity; and a second conduit having a third end connectable to the outlet of the medical reservoir and a fourth end connectable to the injection catheter.

[0031] According to the cerebrospinal fluid circulation circuit described in (11) above, the drainage catheter is insertable into a cavity within the body where cerebrospinal fluid is present, and drains the cerebrospinal fluid outside the body. The fluid, guided through the first end connected to the drainage catheter into the first conduit, passes through the inlet connected to the second end and is introduced into the first chamber. The fluid contained in the first chamber is guided to the second chamber through a flow path connecting the first and second chambers. Here, a one-way valve is provided in the flow path. The one-way valve allows the fluid to move from the first chamber to the second chamber, while preventing the fluid from moving from the second chamber to the first chamber. Furthermore, the only passage through which the fluid can move between the first and second chambers is the flow path with the one-way valve. The fluid contained in the second chamber is drained through the third end connected to the outlet into the second conduit and guided to an infusion catheter connected to the fourth end. The infusion catheter is insertable into the cavity and injects the fluid into the cavity.

[0032] Thus, since the first and second chambers are separated from each other by a one-way valve, even if the pressure inside the second chamber fluctuates, the pressure fluctuations inside the second chamber can be prevented from affecting the pressure inside the first chamber. This prevents phenomena such as obstruction of fluid introduction into the first chamber or backflow of fluid. Furthermore, even if the first chamber is connected to a containment cavity in the body where cerebrospinal fluid exists via the first conduit and drainage catheter, the cerebrospinal fluid circulation circuit according to the present invention can suppress fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed. In addition, the first chamber can function as a reservoir for temporarily storing cerebrospinal fluid that has been drained outside the body. Therefore, the structure of the cerebrospinal fluid circulation circuit according to the present invention can be simplified.

[0033] According to the present invention, it is possible to provide a medical reservoir and a cerebrospinal fluid circulation circuit that can simplify the structure while suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0034] This is a block diagram showing an overview of the cerebrospinal fluid circulation circuit according to this embodiment. This is a plan view showing the vicinity of the inlet of the infusion catheter of this embodiment. This is a plan view showing the vicinity of the outlet of the discharge catheter of this embodiment. This is a cross-sectional view at cross-section B-B shown in Figure 3. This is a cross-sectional view showing a medical reservoir according to this embodiment. This is a cross-sectional view showing a medical reservoir according to the first modified example. This is a cross-sectional view showing a medical reservoir according to the second modified example. This is a cross-sectional view showing a medical reservoir according to the third modified example. This is a cross-sectional view showing a medical reservoir according to the fourth modified example. This is a cross-sectional view at cross-section D-D shown in Figure 9. This is a cross-sectional view showing a medical reservoir according to the fifth modified example. This is a cross-sectional view showing a connector of this embodiment. This is a perspective view showing specific examples of the connector and connector fixing device of this embodiment.

[0035] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The embodiments described below are preferred specific examples of the present invention and therefore have various technically preferred limitations. However, the scope of the present invention is not limited to these embodiments unless otherwise stated in the following description. Furthermore, in each drawing, similar components are denoted by the same reference numerals, and detailed descriptions are omitted as appropriate.

[0036] Figure 1 is a block diagram showing an overview of the cerebrospinal fluid (CSF) circulation circuit according to this embodiment. The cerebrospinal fluid circulation circuit 2 according to this embodiment is a system that injects fluid into a body cavity in which the subject's cerebrospinal fluid (CSF) is present, and pushes the fluid present in the body cavity out of the body cavity by intracranial pressure (ICP), thereby allowing the fluid containing cerebrospinal fluid to drain naturally and circulate. Cerebrospinal fluid is mainly present in the subarachnoid space and ventricles. That is, the body cavity in which cerebrospinal fluid is present includes the subarachnoid space and ventricles. The body cavity in this embodiment is an example of the "containment cavity" of the present invention.

[0037] As shown in Figure 1, the cerebrospinal fluid circulation circuit 2 according to this embodiment comprises a medical reservoir 3, a first conduit 41, and a second conduit 42. The cerebrospinal fluid circulation circuit 2 may further comprise a medical device 5, a connector 6, a first pressure measuring unit 861, and a second pressure measuring unit 862.

[0038] The medical reservoir 3 is made of a flexible resin material and is formed in the shape of a so-called soft bag. As shown in Figure 1, the medical reservoir 3 is connected to the first conduit 41 by a first tube connector 371 and to the second conduit 42 by a second tube connector 372.

[0039] Furthermore, the medical reservoir 3 is connected to the third conduit 43 by a third tube connector 373, and is connected to the artificial cerebrospinal fluid bag 81 via the third conduit 43. The artificial cerebrospinal fluid bag 81 stores artificial cerebrospinal fluid (aCSF) 811 and supplies the artificial cerebrospinal fluid 811 to the medical reservoir 3 through the third conduit 43. The artificial cerebrospinal fluid 811 in this embodiment is an example of the "therapeutic fluid" of the present invention. Examples of artificial cerebrospinal fluid 811 include liquids containing lactated Ringer's solution. However, the artificial cerebrospinal fluid 811 is not limited to liquids containing lactated Ringer's solution.

[0040] Furthermore, the medical reservoir 3 is connected to the fourth conduit 44 by a fourth tube connector 374, and is connected to the oxygen supply source 82 via the fourth conduit 44. The oxygen supply source 82 supplies oxygen to the medical reservoir 3 through the fourth conduit 44. The oxygen in this embodiment is an example of the "gas" of the present invention. A filter 83 may also be provided in the fourth conduit 44. By providing the filter 83, the risk of foreign matter other than oxygen entering the inside of the medical reservoir 3 can be reduced.

[0041] As shown in Figure 1, the medical reservoir 3 has a first chamber 31, a second chamber 32, a one-way valve 34, and a gas introduction section 35. The first chamber 31 temporarily stores cerebrospinal fluid supplied (i.e., discharged) from the body cavity through the first conduit 41. The first chamber 31 also temporarily stores artificial cerebrospinal fluid 811 supplied from the artificial cerebrospinal fluid bag 81 through the third conduit 43. In other words, the first chamber 31 functions as a reservoir.

[0042] The second chamber 32 introduces oxygen supplied from the oxygen supply source 82 through the fourth conduit 44 and the gas introduction section 35 to the fluid supplied from the first chamber 31 through the one-way valve 34. In other words, the second chamber 32 mixes the cerebrospinal fluid supplied from the first chamber 31, the artificial cerebrospinal fluid 811 supplied from the first chamber 31, and the oxygen supplied from the gas introduction section 35 to produce oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution). Thus, the second chamber 32 functions as an oxygenation mechanism utilizing bubbling.

[0043] In the present specification, three forms of liquid, namely cerebrospinal fluid, a mixed solution of cerebrospinal fluid and artificial cerebrospinal fluid 811, and a mixed solution obtained by introducing oxygen into the mixed solution of cerebrospinal fluid and artificial cerebrospinal fluid 811 (i.e., hyperoxygenated solution), may be collectively referred to as "fluid" herein. The detailed structure of the medical reservoir 3 will be described later.

[0044] The first conduit 41 is connectable to the connector 6 at an upstream end 411 thereof, and is connectable to the discharge catheter 51 of the medical device 5 via the connector 6. The upstream end 411 of the present embodiment is an example of the "first end" in the present invention.

[0045] Further, the first conduit 41 is connected to the first tube connector 371 of the medical reservoir 3 at a downstream end 412 thereof. The first tube connector 371 is attached to the inflow port 311 (see FIGS. 5 to 7) of the medical reservoir 3. Therefore, the downstream end 412 of the first conduit 41 is connected to the inflow port 311 via the first tube connector 371. The downstream end 412 of the present embodiment is an example of the "second end" in the present invention. The first conduit 41 guides cerebrospinal fluid discharged from a body cavity to the first chamber 31 of the medical reservoir 3.

[0046] The second conduit 42 is connected to the second tube connector 372 of the medical reservoir 3 at an upstream end 421 thereof. The second tube connector 372 is attached to the discharge port 321 (see FIGS. 5 to 7) of the medical reservoir 3. Therefore, the upstream end 421 of the second conduit 42 is connected to the discharge port 321 via the second tube connector 372. The upstream end 421 of the present embodiment is an example of the "third end" in the present invention.

[0047] Further, the second conduit 42 is connectable to the injection catheter 52 of the medical device 5 via a connector 86 at a downstream end 422 thereof. The downstream end 422 of the present embodiment is an example of the "fourth end" in the present invention.

[0048] As shown in Fig. 1, the second conduit 42 includes a first pump mounting portion 423 and a second pump mounting portion 424 connected to a liquid feeding pump 84. The liquid feeding pump 84 is connected to the second conduit 42 via the first pump mounting portion 423 and the second pump mounting portion 424, and delivers the fluid generated in the second chamber 32 of the medical reservoir 3 toward the inside of a living body (that is, into the body cavity where cerebrospinal fluid exists). Accordingly, an operator or the like can easily incorporate the liquid feeding pump 84 into the cerebrospinal fluid circulation circuit 2 by mounting the liquid feeding pump 84 on the first pump mounting portion 423 and the second pump mounting portion 424. As shown in Fig. 1, an air trap 85 may be provided on the second conduit 42. In this case, the installation position of the air trap 85 is not limited to the position shown in Fig. 1. For example, the air trap 85 may be embedded immediately before the discharge port 321 of the medical reservoir 3. By providing the air trap 85, air bubbles generated when bubbling is performed in the medical reservoir 3 can be eliminated, and the risk of clogging caused by air occurring inside the second conduit 42 or inside the living body can be suppressed. The air trap 85 is not particularly limited as long as it is a mechanism capable of collecting or removing air bubbles.

[0049] The first pressure measuring unit 861 is connected via a branch pipe 45 to the second conduit 42 at a position between the second pump mounting portion 424 of the second conduit and the downstream end 422 of the second conduit 42. The first pressure measuring unit 861 measures the pressure inside the second conduit 42 at a position between the second pump mounting portion 424 and the downstream end 422. Accordingly, the first pressure measuring unit 861 can indirectly estimate fluctuations in intracranial pressure from the pressure of the fluid delivered from the liquid feeding pump 84.

[0050] In this embodiment, the cerebrospinal fluid circulation circuit 2 is a system that circulates fluid containing cerebrospinal fluid by injecting fluid into the body cavity containing the subject's cerebrospinal fluid using a fluid delivery pump 84, and then naturally pushing the fluid present in the body cavity out due to internal pressure. If the natural drainage in the cerebrospinal fluid circulation circuit 2 is obstructed for any reason, and the administered fluid accumulates in the body cavity, there is a concern that intracranial pressure will rise, adversely affecting the brain and spinal cord (so-called hypertension). Therefore, real-time and temporal monitoring of intracranial pressure is necessary when cerebrospinal fluid circulation is performed. In this case, by inferring fluctuations in intracranial pressure from fluctuations in the circuit pressure of the fluid delivered from the fluid delivery pump 84 and passing through the second conduit 42, it is possible to monitor pressure fluctuations when cerebrospinal fluid circulation is performed, and it is also expected that excessive increases in intracranial pressure can be detected early. Furthermore, it can detect not only internal abnormalities such as increased intracranial pressure, but also abnormal fluctuations in circuit pressure when circuit abnormalities occur, such as when a conduit in the circulatory circuit kinks or when fluid leakage occurs at the connection point of the circuit by a connector.

[0051] The second pressure measuring unit 862 is connected to the first conduit 41 via a branch pipe 46. The second pressure measuring unit 862 measures the pressure inside the first conduit 41. This allows the second pressure measuring unit 862 to measure intracranial pressure. Note that the second pressure measuring unit 862 is not necessarily required.

[0052] As shown in Figure 1, the medical device 5 has an drainage catheter 51 and an infusion catheter 52, and is inserted into the subarachnoid space from near the lumbar spine while the patient is in a lateral decubitus position. The tip position of the infusion catheter 52 is preferably between the position of the sixth thoracic vertebra from the top, called T6, and the first lumbar vertebra from the top, called L1, taking safety into consideration during insertion. For example, as shown by arrow A11 in Figure 1, the drainage catheter 51 aspirates cerebrospinal fluid present in the body cavity from the drainage port 511 and drains it out of the body cavity. For example, as shown by arrow A13 in Figure 1, the infusion catheter 52 injects fluid from the infusion port 521 into the body cavity, such as the subarachnoid space, where cerebrospinal fluid is present.

[0053] The body cavities where cerebrospinal fluid exists (e.g., the subarachnoid space and ventricles) are almost closed spaces. Furthermore, the pressure inside the first chamber 31 of the medical reservoir 3 is maintained at approximately atmospheric pressure, which is lower than the intracranial pressure. Therefore, when the fluid delivery pump 84 delivers the fluid generated in the second chamber of the medical reservoir 3 toward the body cavity, the cerebrospinal fluid present in the body cavity is naturally pushed out by the intracranial pressure from the outlet 511 of the drainage catheter 51 into the lumen of the drainage catheter 51, and is then discharged outside the body through the drainage catheter 51.

[0054] In this case, if cerebrospinal fluid is mechanically aspirated using a fluid delivery pump 84 or the like, there is a possibility that an excessive amount of cerebrospinal fluid may be aspirated. Therefore, the cerebrospinal fluid circulation circuit 2 according to this embodiment utilizes the pressure gradient between the intracranial pressure in the subarachnoid space and the internal pressure in the medical reservoir 3 to discharge cerebrospinal fluid from within the body cavity, thereby suppressing excessive discharge of cerebrospinal fluid and avoiding the risk of developing conditions such as low cerebrospinal fluid pressure syndrome.

[0055] Next, the medical device 5 of this embodiment will be described with reference to the drawings. Figure 2 is a plan view showing the vicinity of the inlet port of the infusion catheter of this embodiment. Figure 3 is a plan view showing the vicinity of the outlet port of the discharge catheter of this embodiment. Figure 4 is a cross-sectional view taken along the cross-section B-B shown in Figure 3.

[0056] As shown in Figure 3, the tip of the drainage catheter 51 is open as an outlet 511 and is positioned in the subarachnoid space near the lumbar spine. For example, as shown by arrows A11 and A12 in Figure 3, the drainage catheter 51 is inserted into the subject's subarachnoid space and aspirates cerebrospinal fluid present in the subarachnoid space near the lumbar spine through the outlet 511 into the space 53 (see Figure 4) between the lumen 513 of the drainage catheter 51 and the outer surface of the infusion catheter 52. As previously mentioned with respect to Figure 1, the force for aspirating cerebrospinal fluid is provided by the fluid delivery pump 84. The drainage catheter 51 then discharges the cerebrospinal fluid outside the subject's body cavity through the space 53.

[0057] The outer diameter of the infusion catheter 52 is smaller than the inner diameter of the discharge catheter 51. The infusion catheter 52 can be positioned in the lumen 513 of the discharge catheter 51. Furthermore, the infusion catheter 52 is not connected to the discharge catheter 51 and can move along the longitudinal direction D1 (see Figure 3) of the discharge catheter 51 in the lumen 513 of the discharge catheter 51. Since the tip of the discharge catheter 51 is open as an outlet 511, the tip of the infusion catheter 52 can pass through the outlet 511 of the discharge catheter 51, as shown in Figure 3.

[0058] As a result, the tip of the infusion catheter 52 is exposed from the outlet 511 of the discharge catheter 51 in the longitudinal direction D1 of the discharge catheter 51. The distance in the longitudinal direction D1 between the tip of the discharge catheter 51 and the tip of the infusion catheter 52 exposed from the outlet 511 of the discharge catheter 51 can be adjusted to a predetermined distance. In this specification, the "predetermined distance" can be, for example, 0 cm or more and 30 cm or less. This makes it possible to avoid the risks that occur when inserting the catheter deeply into the patient's subarachnoid space.

[0059] As shown in Figure 2, the tip of the infusion catheter 52 is open as an inlet 521, and passes through the outlet 511 of the discharge catheter 51 to be placed in the subarachnoid space. For example, as shown by arrow A13 in Figure 2, the infusion catheter 52 is inserted into the patient's subarachnoid space, and fluid is injected into the subarachnoid space where cerebrospinal fluid is present through the lumen 523 of the infusion catheter 52 (see Figure 4). As mentioned above with respect to Figure 1, the force for injecting fluid into the subarachnoid space is provided by the fluid delivery pump 84.

[0060] In a cross-section B-B perpendicular to the longitudinal direction D1 (see Figure 4), the cross-sectional area of ​​the space 53 between the outside of the infusion catheter 52 and the inside of the discharge catheter 51 is set within a predetermined ratio range to the cross-sectional area of ​​the lumen 523 of the infusion catheter 52 in order to keep the intracranial pressure constant within a predetermined range. Since it is undesirable for the intracranial pressure to exceed or fall below a limit range, it is preferable that the ratio of the cross-sectional area of ​​the space 53 to the cross-sectional area of ​​the lumen 523 be set within a certain range centered on 1. In this specification, the "predetermined ratio" is preferably, for example, 0.5 times or more and 2 times or less. However, the "predetermined ratio" in this specification is not limited to 0.5 times or more and 2 times or less, and may be changed according to the fluid velocity and flow rate in the cerebrospinal fluid circulation circuit 2.

[0061] Next, the medical reservoir 3 according to this embodiment will be described in detail with reference to the drawings. Figure 5 is a cross-sectional view showing the medical reservoir according to this embodiment. As mentioned above with respect to Figure 1, the medical reservoir 3 is made of a flexible resin material and is formed in the shape of a plastic infusion container (a so-called soft bag). That is, the medical reservoir 3 consists of a soft bag. Suitable resin materials include polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and ethylene vinyl acetate copolymer (EVA). Also, as shown in Figure 5, the medical reservoir 3 of this embodiment has a first chamber 31, a second chamber 32, a partition wall 33, and a one-way valve 34.

[0062] The first chamber 31 has an inlet 311 and an inlet 312. The inlet 311 penetrates the first chamber 31 and is formed to introduce fluid from outside the first chamber 31 into the first chamber 31, as shown by arrow A21 in Figure 5. As described above with respect to Figure 1, the first tube connector 371, which is connected to the downstream end 412 of the first conduit 41, is attached to the inlet 311. Thus, the downstream end 412 of the first conduit 41 is connected to the inlet 311 via the first tube connector 371.

[0063] The inlet 312 penetrates the first chamber 31 and is formed to introduce artificial cerebrospinal fluid 811 from outside the first chamber 31 into the first chamber 31, as shown by arrow A26 in Figure 5. As shown in Figure 1, a third tube connector 373, which is connected to the third conduit 43, is attached to the inlet 312. Thus, the third conduit 43 is connected to the inlet 312 via the third tube connector 373. The inlet 312 may be formed in the second chamber 32, or in both the first chamber 31 and the second chamber 32. That is, the inlet 312 is formed in at least one of the first chamber 31 and the second chamber 32.

[0064] The second chamber 32 has an outlet 321 and an exit port 322. The outlet 321 penetrates the second chamber 32 and is formed to discharge fluid from the inside of the second chamber 32 to the outside of the second chamber 32, as shown by arrow A23 in Figure 5. As described above with respect to Figure 1, the second tube connector 372, which is connected to the upstream end 421 of the second conduit 42, is attached to the outlet 321. Thus, the upstream end 421 of the second conduit 42 is connected to the outlet 321 via the second tube connector 372.

[0065] The discharge port 322 penetrates the second chamber 32 and is formed to release gas from inside the second chamber 32 to the outside of the second chamber 32. That is, as shown in Figure 5, the medical reservoir 3 further has a pressure release section 36. The pressure release section 36 is provided to maintain the pressure inside the second chamber 32 below a predetermined pressure. The pressure release section 36 is provided connected to the second chamber 32 and has a pressure release conduit 361 and a pressure release valve 362.

[0066] The pressure relief conduit 361 is attached to the outlet 322 and guides the gas inside the second chamber 32 to the pressure relief valve 362. The pressure relief valve 362 is located at the end of the pressure relief conduit 361. As shown by arrow A27 in Figure 5, the pressure relief valve 362 appropriately connects the inside of the second chamber 32 to the outside of the second chamber 32, thereby releasing the gas inside the second chamber 32 that has been guided through the pressure relief conduit 361 to the outside of the second chamber 32. As a result, the pressure relief section 36 maintains the pressure inside the second chamber 32 below a predetermined pressure.

[0067] Examples of pressure relief valves 362 include positive pressure relief valves and filters. The positive pressure relief valve opens when it receives a positive pressure exceeding a predetermined level, releasing the gas inside the second chamber 32 to the outside of the second chamber 32. The filter releases the gas inside the second chamber 32 to the outside of the second chamber 32 through gaps formed in the filter itself.

[0068] The type of pressure relief valve 362 is not limited to those exemplified above, and can be appropriately selected depending on the intended use of the medical reservoir 3. For example, selecting a positive pressure relief valve as the pressure relief valve 362 allows for a quicker response to pressure increases inside the second chamber 32. Also, selecting a filter as the pressure relief valve 362 prevents direct communication between the gas inside the second chamber 32 and the gas outside, thereby suppressing the risk of contamination by bacteria and viruses.

[0069] The partition wall 33 is provided between the first chamber 31 and the second chamber 32, separating the first chamber 31 and the second chamber 32. As shown in Figure 5, the partition wall 33 has a flow path 331. The flow path 331 penetrates the partition wall 33 and connects the first chamber 31 and the second chamber 32. In this case, the partition wall 33 is preferably configured to be inclined from the first chamber 31 toward the second chamber 32. By having the partition wall 33 in this configuration, the fluid introduced into the first chamber 31 can be collected more efficiently toward the flow path 331.

[0070] The one-way valve 34 is installed in a flow path 331 formed in the partition wall 33. The one-way valve 34 is a so-called check valve, allowing fluid to move in only one direction. Specifically, as shown by arrow A22 in Figure 5, the one-way valve 34 allows fluid to move from the first chamber 31 to the second chamber 32, while preventing fluid from moving from the second chamber 32 to the first chamber 31. The term "fluid" here includes not only liquids but also gases. In this case, the flow path 331 and the one-way valve 34 provided in the partition wall 33 are not necessarily limited to just one location, but may be provided in multiple locations on the partition wall 33 depending on the purpose and application.

[0071] The only passage through which the fluid can move between the first chamber 31 and the second chamber 32 is the flow path 331, which is equipped with the one-way valve 34. That is, the fluid flows only in this order (i.e., in this direction) through the inlet 311, the first chamber 31, the flow path 331 equipped with the one-way valve 34, the second chamber 32, and the outlet 321. In other words, in the medical reservoir 3 according to this embodiment, there are no flow paths other than the flow path 331 equipped with the one-way valve 34 that allow the fluid to move in directions other than those permitted by the one-way valve 34. For example, there are no flow paths in the medical reservoir 3 according to this embodiment that allow the fluid to move from the second chamber 32 to the first chamber 31. As mentioned above, if the flow paths 331 and one-way valves 34 are provided at multiple locations on the partition wall 33, the fluid will be allowed to move in only one direction by each one-way valve 34, moving from the first chamber 31 to the second chamber 32.

[0072] Examples of one-way valves 34 include umbrella valves and duckbill valves. When the one-way valve 34 receives pressure from the fluid stored in the first chamber 31, it opens at a pressure of, for example, 5 mmHg or less, allowing the fluid to move from the first chamber 31 to the second chamber 32. The opening pressure strength and type of valve of the one-way valve 34 are not limited to those mentioned above and can be appropriately selected based on the internal volumes of the first chamber 31 and the second chamber 32, as well as the purpose and application.

[0073] As shown in Figure 5, the medical reservoir 3 further includes a gas introduction section 35. The gas introduction section 35 has lumens that communicate with the outside by sealing a part of the medical reservoir 3, for example, by heat fusion, on the lateral portions of the first chamber 31 and the second chamber 32, and extends from the upper end of the first chamber 31 to the lower end of the second chamber 32. Note that the method of creating the gas introduction section 35 is not limited to sealing by heat fusion, but any method that ensures a route for fluid communication between the outside and the inside of the second chamber 32 is acceptable, such as attaching it by directly inserting a needle or tube from the outside towards the second chamber 32.

[0074] Here, as shown in Figure 5, in this specification, "upward" means the direction from the second chamber 32 to the first chamber 31, or the side of the first chamber 31 as viewed from the second chamber 32. Also, in this specification, "downward" means the direction from the first chamber 31 to the second chamber 32, or the side of the second chamber 32 as viewed from the first chamber 31. In other words, as shown in Figure 1, when the medical reservoir 3 is used in the cerebrospinal fluid circulation circuit 2, it is installed in the cerebrospinal fluid circulation circuit 2 such that the first chamber 31 is positioned above the vertical line as viewed from the second chamber 32, and the second chamber 32 is positioned below the vertical line as viewed from the first chamber 31.

[0075] The gas introduction section 35 has a vent 351. The vent 351 penetrates the upper end of the gas introduction section 35 and is formed to introduce gas from the outside of the gas introduction section 35 into the inside of the gas introduction section 35, as shown by arrow A24 in Figure 5.

[0076] As shown in Figure 5, the fourth tube connector 374, which is connected to the fourth conduit 44, is attached to the vent 351. In this way, the fourth conduit 44 is connected to the vent 351 via the fourth tube connector.

[0077] The gas inlet 35 further has an exhaust port 352. The exhaust port 352 penetrates the lower end of the gas inlet 35 (i.e., the end opposite to the vent 351) and is formed to discharge gas from the inside of the gas inlet 35 to the outside of the gas inlet 35 (i.e., into the second chamber 32), as shown by arrow A25 in Figure 5.

[0078] Next, the operation of the medical reservoir 3 according to this embodiment will be explained. As shown by arrow A21 in Figure 5, cerebrospinal fluid discharged from the body cavity through the drainage catheter 51 (see Figure 1) and the first conduit 41 passes through the inlet 311 of the first chamber 31 and is temporarily stored inside the first chamber 31 as fluid 91. Also, when artificial cerebrospinal fluid 811 is supplied from the artificial cerebrospinal fluid bag 81, as shown by arrow A26 in Figure 5, the artificial cerebrospinal fluid 811 passes through the inlet 312 of the first chamber 31 and is temporarily stored inside the first chamber 31 as fluid 91. For example, the artificial cerebrospinal fluid 811 is supplied inside the first chamber 31 before the cerebrospinal fluid circulation circuit 2 starts circulating the fluid containing cerebrospinal fluid. In this way, the first chamber 31 has the function of a reservoir.

[0079] Next, the one-way valve 34 opens when it receives pressure (for example, a pressure of 5 mmHg or less) from the fluid 91 stored in the first chamber 31. As a result, as shown by arrow A22 in Figure 5, the fluid 91 passes through the flow path 331 of the partition wall 33 by its own weight and is guided to the second chamber 32 (i.e., falls).

[0080] Furthermore, as shown by arrow A24 in Figure 5, oxygen supplied from the oxygen supply source 82 through the fourth conduit 44 is guided into the lumen of the gas introduction section 35 by passing through the vent 351 of the gas introduction section 35. As shown by arrow A25 in Figure 5, the oxygen guided into the lumen of the gas introduction section 35 passes through the exhaust port 352 of the gas introduction section 35 and is supplied into the second chamber 32, where it is introduced as bubbles into the fluid 91 contained in the second chamber 32. As a result, oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution) is generated as fluid 92 in the second chamber 32. In this way, the second chamber 32 functions as an oxygenation mechanism utilizing bubbling. Note that a filter (not shown) may be provided at the exhaust port 352 to decompose the gas (oxygen) introduced into the second chamber 32 into finer bubbles.

[0081] Since oxygen is supplied to the inside of the second chamber 32 by the gas introduction section 35, the pressure inside the second chamber 32 becomes higher than atmospheric pressure. Therefore, as shown by arrow A27 in Figure 5, the pressure release section 36 releases the gas inside the second chamber 32 to the outside of the second chamber 32, maintaining the pressure inside the second chamber 32 below a predetermined pressure. Furthermore, as mentioned above, the one-way valve 34 allows the movement of gas from the first chamber 31 to the second chamber 32, while preventing the movement of gas from the second chamber 32 to the first chamber 31.

[0082] Therefore, even if the pressure inside the second chamber 32 becomes higher than atmospheric pressure, the internal pressure is released to the outside by the pressure release section 36, thus suppressing the effect of pressure fluctuations inside the second chamber 32 on the pressure inside the first chamber 31. Furthermore, even if a malfunction occurs in the pressure release section 36 and it is unable to release the gas inside the second chamber 32 to the outside, the effect of pressure fluctuations inside the second chamber 32 on the pressure inside the first chamber 31 can still be suppressed. As a result, the medical reservoir 3 according to this embodiment can suppress fluctuations in intracranial pressure even when oxygenation and circulation of cerebrospinal fluid are performed.

[0083] Next, as shown by arrow A23 in Figure 5, the fluid 92 generated in the second chamber 32 is drawn in by the fluid delivery pump 84, passes through the outlet 321, and is injected into the body cavity through the second conduit 42 and the injection catheter 52 (see Figure 1).

[0084] As described above, in the medical reservoir 3 according to this embodiment, the one-way valve 34 provided in the flow path 331 of the partition wall 33 allows the movement of fluid from the first chamber 31 to the second chamber 32, while preventing the movement of fluid from the second chamber 32 to the first chamber 31. Furthermore, the only passage through which fluid can move between the first chamber 31 and the second chamber 32 is the flow path 331 where the one-way valve 34 is provided. In this way, since the first chamber 31 and the second chamber 32 are separated from each other by the one-way valve 34, even if the pressure inside the second chamber 32 fluctuates, it is possible to suppress the effect of the pressure fluctuations inside the second chamber 32 on the pressure inside the first chamber 31.

[0085] This prevents phenomena that would hinder the introduction of fluid into the first chamber 31 or cause fluid backflow. Furthermore, even when the first chamber 31 is connected to a biological containment cavity where cerebrospinal fluid exists via the first conduit 41 and the discharge catheter 51, in the medical reservoir 3 according to this embodiment, the second chamber 32, which becomes positively pressurized by bubbling, does not directly communicate with the biological containment cavity. If the medical reservoir 3 is not separated into two chambers (the first chamber 31 and the second chamber 32 in this embodiment) by a partition wall 33, for example, an increase in internal pressure due to bubbling exceeding the allowable amount or a malfunction of the pressure release section 36 could reverse the pressure gradient between the intracranial pressure and the internal pressure of the medical reservoir 3, raising concerns about cerebrospinal fluid backflow and the resulting increase in intracranial pressure. Also, even if the medical reservoir 3 is divided into two chambers, there is a risk that the internal pressure of the medical reservoir 3 will rise excessively if the pressure release section 36 malfunctions for some reason.

[0086] In contrast, the medical reservoir 3 according to this embodiment is divided by a partition wall 33 and a one-way valve 34 into a first chamber 31 that communicates directly with the containment cavity in the body and a second chamber 32 that adds oxygen to the cerebrospinal fluid by bubbling. This suppresses the interlocking of the internal pressure in the first chamber 31 and the internal pressure in the second chamber 32, thereby suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0087] Furthermore, the gas introduction unit 35 introduces oxygen supplied from the outside into the fluid 91 contained in the second chamber 32. As a result, the gas introduction unit 35 can perform bubbling in the second chamber 32 and generate oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution) as the fluid 92. Thus, the medical reservoir 3 according to this embodiment can simplify its structure by combining the first chamber 31, which functions as a reservoir, and the second chamber 32, which functions as a simple oxygenation mechanism using bubbling, while suppressing fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed. Moreover, by having one medical reservoir 3 perform both the roles of reservoir and oxygenation mechanism, the elements constituting the entire cerebrospinal fluid circulation circuit 2 are significantly simplified compared to when using an oxygenation mechanism such as an artificial lung, leading to improved operability when performing circulation operations.

[0088] Furthermore, the pressure release section 36 is provided in the second chamber 32, and maintains the pressure inside the second chamber 32 below a predetermined pressure. Therefore, even if the pressure inside the second chamber 32 rises due to bubbling or other operations, the pressure release section 36 releases the pressure inside the second chamber 32 to the outside and maintains it below a predetermined pressure, thereby more reliably suppressing the effect of pressure fluctuations inside the second chamber 32 on the pressure inside the first chamber 31.

[0089] Furthermore, at least one of the first chamber 31 and the second chamber 32 has an inlet 312 for introducing artificial cerebrospinal fluid 811 from outside the medical reservoir 3 into the medical reservoir 3. Therefore, for example, a surgeon can inject artificial cerebrospinal fluid 811 into the medical reservoir 3 through the inlet 312 provided in at least one of the first chamber 31 and the second chamber 32 before performing cerebrospinal fluid circulation.

[0090] Furthermore, the one-way valve 34 is, for example, an umbrella valve or a duckbill valve, and opens at a pressure of, for example, 5 mmHg or less. This allows the one-way valve 34 to be opened at a relatively low pressure, and ensures a sufficient flow path when the valve body is opened, thus more reliably allowing the fluid to move from the first chamber 31 to the second chamber 32 even when the pressure inside the second chamber 32 fluctuates.

[0091] Next, a modified example of the medical reservoir according to this embodiment will be described with reference to the drawings. If the components of the modified medical reservoir are the same as those of the medical reservoir 3 described above with respect to Figure 5, redundant explanations will be omitted as appropriate, and the differences will be the focus of the description below.

[0092] Figure 6 is a cross-sectional view showing a medical reservoir according to the first modified example. The medical reservoir 3A according to this modified example has a first chamber 31A, a second chamber 32A, a flow path 33A, and a one-way valve 34.

[0093] The first chamber 31A and the second chamber 32A are provided separately and are separated from each other. The size of the first chamber 31A may be the same as or different from the size of the second chamber 32A. Also, the material of the first chamber 31A may be the same as or different from the material of the second chamber 32A. The medical reservoir 3A according to this modified example is formed of a flexible resin material, similar to the medical reservoir 3 described above with respect to Figure 5, and is formed in a so-called soft bag shape.

[0094] As shown in Figure 6, the first chamber 31A has a first flow channel opening 313. The first flow channel opening 313 is formed in a position opposite to the second chamber 32A and penetrates the first chamber 31A. The second chamber 32A has a second flow channel opening 323. The second flow channel opening 323 is formed in a position opposite to the first chamber 31A and penetrates the second chamber 32A.

[0095] The flow path 33A is provided between the first chamber 31A and the second chamber 32A, connecting the first chamber 31A and the second chamber 32A. Specifically, the upstream end of the flow path 33A is attached to the first flow path opening 313 of the first chamber 31A. The downstream end of the flow path 33A is attached to the second flow path opening 323 of the second chamber 32A. In this way, the flow path 33A connects the first chamber 31A and the second chamber 32A.

[0096] The one-way valve 34 is installed in the flow path 33A. The one-way valve 34 is a so-called check valve, which allows the movement of fluid from the first chamber 31A to the second chamber 32A, while preventing the movement of fluid from the second chamber 32A to the first chamber 31A. This point has been described above with respect to Figure 5.

[0097] The medical reservoir 3A further includes a gas introduction section 35A. The gas introduction section 35A has a lumen that communicates with the outside by sealing a part of the medical reservoir 3A, for example, by heat fusion, on the side of the second chamber 32A, and extends from the upper end to the lower end of the second chamber 32A. The other structures are the same as those of the medical reservoir 3 described above with respect to Figure 5.

[0098] As explained above, in the medical reservoir 3A according to this modified example, the first chamber 31A and the second chamber 32A are provided separately and are separated from each other. The flow path 33A is provided between the first chamber 31A and the second chamber 32A and connects the first chamber 31A and the second chamber 32A. The one-way valve 34 is installed in the flow path 33A and allows the movement of fluid from the first chamber 31A to the second chamber 32A, while preventing the movement of fluid from the second chamber 32A to the first chamber 31A. The only passage through which fluid can move between the first chamber 31A and the second chamber 32A is the flow path 33A where the one-way valve 34 is provided.

[0099] Therefore, even if the pressure inside the second chamber 32A fluctuates due to bubbling operations or other reasons, the pressure fluctuation inside the second chamber 32A can be more reliably suppressed from affecting the pressure inside the first chamber 31A. As a result, even when the first chamber 31A is connected to a biological containment cavity where cerebrospinal fluid is present via the first conduit 41 and the drainage catheter 51, the medical reservoir 3A according to this modified example can suppress fluctuations in intracranial pressure when cerebrospinal fluid circulation is performed.

[0100] Furthermore, since the first chamber 31A and the second chamber 32A are provided as separate components, the degree of freedom in selecting the size and materials of each chamber is increased. As a result, the medical reservoir 3A according to this modified example can be made even simpler in structure. Moreover, the effects described above with respect to Figure 5 can be similarly obtained in the medical reservoir 3A according to this modified example.

[0101] Figure 7 is a cross-sectional view showing a medical reservoir according to a second modified example. The medical reservoir 3B according to this modified example has a first chamber 31, a second chamber 32, a partition wall 33, and a one-way valve 34. The medical reservoir 3B further has a gas introduction section 35B and a pressure release section 36B. The medical reservoir 3A according to this modified example is formed of a flexible resin material, similar to the medical reservoir 3 described above with respect to Figure 5, and is formed in a so-called soft bag shape.

[0102] As shown in Figure 7, the gas introduction section 35B is attached to the lower part of the second chamber 32 by sealing a part of the medical reservoir 3B, for example by heat fusion, and extends along the bottom surface of the second chamber 32. The fourth tube connector 374, which is connected to the fourth conduit 44 (see Figure 1), is attached to the vent 351. Thus, the fourth conduit 44 is connected to the vent 351 via the fourth tube connector 374.

[0103] Furthermore, a one-way valve 34B is attached to the fourth tube connector 374. The one-way valve 34B is a so-called check valve, which allows fluid to move in only one direction. Specifically, as shown by arrow A28 in Figure 7, the one-way valve 34B allows fluid to move from outside the second chamber 32 to inside the second chamber 32, while preventing fluid from moving from inside the second chamber 32 to outside the second chamber 32. The term "fluid" here includes not only liquids but also gases.

[0104] As a result, even if the gas introduction section 35B is located in the lower part of the second chamber 32, the one-way valve 34B can prevent the fluid 92 stored in the second chamber 32 from leaking out of the second chamber 32 through the gas introduction section 35B to the outside of the second chamber 32.

[0105] As shown in Figure 7, the pressure release section 36B is attached to the side portion of the first chamber 31, that is, the portion above the second chamber 32, by sealing a part of the medical reservoir 3B, for example by heat fusion, and is connected to the second chamber 32. The pressure release section 36B has a pressure release conduit 361, a pressure release valve 362, and an air guide section 363. As shown by arrow A27 in Figure 5, the pressure release valve 362 appropriately connects the inside of the second chamber 32 to the outside of the second chamber 32, thereby releasing the gas inside the second chamber 32, which has been guided through the air guide section 363 and the pressure release conduit 361, to the outside of the second chamber 32. In this way, the pressure release section 36B maintains the pressure inside the second chamber 32 below a predetermined pressure. This point is as described above with respect to Figure 5. The other structure is the same as the structure of the medical reservoir 3 described above with respect to Figure 5.

[0106] As explained above, in the medical reservoir 3B according to this modified example, the pressure release section 36B is provided in a portion above the second chamber 32. Therefore, it is possible to prevent the fluid 92 stored in the second chamber 32 from leaking out of the second chamber 32 through the pressure release section 36B to the outside of the second chamber 32.

[0107] Furthermore, the gas introduction section 35B is provided in the lower part of the second chamber 32 and extends along the bottom surface of the second chamber 32. Therefore, even if the medical reservoir 3B is deformed by an external force applied to it, or by the weight of the fluid 91 stored in the first chamber 31 and the fluid 92 stored in the second chamber 32, the gas introduction section 35B can be prevented from becoming blocked. This ensures a flow path for oxygen supplied from the oxygen supply source 82 (see Figure 1) to the inside of the second chamber 32 through the fourth conduit 44, thereby improving the efficiency of fluid 92 (i.e., highly oxygenated solution) generation. Moreover, the effects described above with respect to Figure 5 can be similarly obtained in the medical reservoir 3B according to this modified example.

[0108] Figure 8 is a cross-sectional view showing a medical reservoir according to the third modified example. The medical reservoir 3C according to this modified example has a first chamber 31C, a second chamber 32, a partition wall 33C, and a one-way valve 34. The medical reservoir 3C according to this modified example is formed of a flexible resin material, similar to the medical reservoir 3 described above with respect to Figure 5, and is formed in a so-called soft bag shape.

[0109] As shown in Figure 8, the partition wall 33C is inclined toward the center of the medical reservoir 3C as it moves from the first chamber 31C to the second chamber 32. This allows the fluid introduced into the first chamber 31C through the inlet 311 to be collected more efficiently toward the flow path 331. Furthermore, compared to the case where the partition wall is configured to be horizontal, the water pressure on the flow path 331 is higher due to the fluid, so that the pressure necessary to open the one-way valve 34 can be maintained even when the overall volume of the medical reservoir 3C is reduced.

[0110] The medical reservoir 3C further includes a pressure release filter 364. The pressure release filter 364 is an example of the "pressure release section" of the present invention and has the same function as the pressure release valve 362 described above with respect to Figure 5. That is, the pressure release filter 364 is provided inside the medical reservoir 3C by cutting out a part of the medical reservoir 3C (for example, the outer surface 38) and embedding it in its place, and is bonded to the inner surface 37 of the medical reservoir 3C with an adhesive or the like. As shown by arrows A51 and A52 in Figure 8, the pressure release filter 364 releases the gas inside the second chamber 32 to the outside of the second chamber 32 through a gap formed in the pressure release filter 364 itself. In this way, the pressure release filter 364 maintains the pressure inside the second chamber 32 below a predetermined pressure.

[0111] To suppress the risk of bacteria and viruses contaminating the fluid in the medical reservoir 3C, the mesh size of the pressure release filter 364 is preferably, for example, 0.2 μm or more and 0.4 μm or less. Furthermore, the pressure release filter 364 is preferably a filter that can move only gas in both directions and is preferably a filter that can prevent the passage of liquids such as water. To suppress damage and contamination of the pressure release filter 364, a member covering the pressure release filter 364 may be provided on the outside of the medical reservoir 3C (for example, on the outer surface 38). Note that the number of pressure release filters 364 installed is not limited to one. For example, multiple pressure release filters 364 may be installed depending on the type of filter, etc. Also, the size and shape of the pressure release filter 364 are not limited to the size and shape exemplified in Figure 8.

[0112] As shown by arrow A29 in Figure 8, oxygen supplied from the oxygen supply source 82 (see Figure 1) passes through the outlet 321 and is supplied into the second chamber 32, where it is introduced as bubbles into the fluid 91 contained in the second chamber 32. As a result, oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution) is generated as fluid 92 in the second chamber 32.

[0113] In other words, the second tube connector 372 attached to the outlet 321 functions as a bubbling port. For example, a medical professional inserts a bottle needle or the like into the second tube connector 372 to perform a bubbling operation. Thus, the medical reservoir 3C does not have a lumen for introducing gas that communicates with the outside by sealing a part of the medical reservoir 3C by heat fusion or the like, but rather has a second tube connector 372 that functions as a bubbling port. The other structures are the same as the structure of the medical reservoir 3 described above with respect to Figure 5.

[0114] As explained above, in the modified medical reservoir 3C, the pressure release filter 364 is provided inside the medical reservoir 3C. Therefore, compared to the medical reservoir 3 described in Figure 5 and the medical reservoir 3A described in Figure 6, it is possible to reduce the risk of medical personnel getting caught on the pressure release section 36 when using the medical reservoir 3C. Also, compared to the medical reservoir 3B described in Figure 7, it is possible to reduce the risk of the air guide section 363 of the pressure release section 36B kinking due to the weight of the pressure release valve 362, etc. Thus, since the pressure release filter 364 is provided inside the medical reservoir 3C and does not protrude outward from the outer surface 38 of the medical reservoir 3C, the risk of medical personnel getting caught or kinking can be reduced.

[0115] Figure 9 is a cross-sectional view showing a medical reservoir according to the fourth modified example. Figure 10 is a cross-sectional view taken along the line D-D shown in Figure 9. The medical reservoir 3D according to this modified example has a first chamber 31D, a second chamber 32, a partition wall 33D, and a one-way valve 34. The medical reservoir 3D according to this modified example is formed from a flexible resin material, similar to the medical reservoir 3 described above with respect to Figure 5, and is formed in the shape of a so-called soft bag.

[0116] The medical reservoir 3D further comprises a fixing device 39 and a pressure release filter 364. The fixing device 39 and pressure release filter 364 in this modified example are examples of the "pressure release section" of the present invention. The fixing device 39 is provided at the top of the first chamber 31D and the second chamber 32. The fixing device 39 is made of a resin material that is harder than the resin material forming the first chamber 31D and the second chamber 32, and houses and fixes the pressure release filter 364. Specifically, as shown in Figure 10, the pressure release filter 364 is provided inside the fixing device 39 and is bonded to the inner wall 395 of the fixing device 39 with an adhesive or the like. A specific example of the pressure release filter 364 is as described above with respect to Figure 8.

[0117] The fixing device 39 has a first pressure release conduit 391 and a second pressure release conduit 392. The first pressure release conduit 391 is located at the bottom of the fixing device 39 and connects the second chamber 32 to the first space 393 inside the fixing device 39. The second pressure release conduit 392 is located at the top of the fixing device 39 and connects the second space 394 inside the fixing device 39 to the outside of the fixing device 39. As shown in Figure 10, the first space 393 and the second space 394 are separated by a pressure release filter 364. That is, the pressure release filter 364 divides the inside of the fixing device 39 into the first space 393 and the second space 394. This reduces the risk of bacteria and viruses contaminating the fluid in the medical reservoir 3D.

[0118] The number of first pressure relief conduits 391 and second pressure relief conduits 392 installed is not particularly limited; there may be one or two or more. In the medical reservoir 3D shown in Figure 9, there are two first pressure relief conduits 391 and two second pressure relief conduits 392 installed.

[0119] As shown by arrow A29 in Figure 9, oxygen supplied from the oxygen supply source 82 (see Figure 1) passes through the outlet 321 and is supplied into the second chamber 32, where it is introduced as bubbles into the fluid 91 contained in the second chamber 32. As a result, oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution) is generated as fluid 92 in the second chamber 32.

[0120] As shown by arrow A53 in Figures 9 and 10, the gas inside the second chamber 32 is guided through the first pressure relief conduit 391 to the first space 393 inside the fixture 39. As shown by arrow A54 in Figure 10, the gas guided into the first space 393 inside the fixture 39 passes through the pressure relief filter 364 and is guided into the second space 394 inside the fixture 39. As shown by arrow A55 in Figures 9 and 10, the gas guided into the second space 394 inside the fixture 39 is guided to the outside of the fixture 39 through the second pressure relief conduit 392. In this way, the fixture 39 and the pressure relief filter 364 maintain the pressure inside the second chamber 32 below a predetermined pressure. The other structures are the same as those of the medical reservoir 3C described above with respect to Figure 8.

[0121] As explained above, in the medical reservoir 3D according to this modified example, the fixing device 39 for housing and fixing the pressure release filter 364 is provided at the top of the first chamber 31D and the second chamber 32. Therefore, compared with the medical reservoir 3C described above with respect to Figure 8, the medical reservoir 3D can be prevented from bending due to the weight of the pressure release filter 364. This reduces the risk of the flow path 331 becoming blocked. In addition, since it is not necessary to embed the pressure release filter 364 in the medical reservoir 3D, the pressure release filter 364 can be easily installed compared with the medical reservoir 3C described above with respect to Figure 8. This simplifies the manufacturing process of the medical reservoir 3D according to this modified example.

[0122] Furthermore, as shown by the dashed line in Figure 10, the fixing device 39 may have a hook 396. In this case, medical personnel can use the hook 396 to suspend the medical reservoir 3D, thereby preventing the medical reservoir 3D from breaking due to the weight of the fixing device 39. This further reduces the risk of the flow path 331 becoming blocked.

[0123] Figure 11 is a cross-sectional view showing a medical reservoir according to the fifth modified example. The medical reservoir 3E according to this modified example is formed from a resin material that is harder than the resin material used to form the medical reservoirs 3, 3A, 3B, 3C, and 3D described above with respect to Figures 5 to 10. Examples of the resin material used to form the medical reservoir 3E according to this modified example include polycarbonate (PC) and polyolefin resins.

[0124] In this case, the material selected as the "hard resin material" is not limited to the aforementioned material, but any material that minimizes changes in the overall external shape of the medical reservoir 3E even when the fluid 91 is introduced into the medical reservoir 3E or when the internal pressure of the second chamber 32E increases due to high oxygenation caused by bubbling is acceptable. By selecting such a material, the internal volume and overall shape of the medical reservoir 3E, including the first chamber 31E and the second chamber 32E, are maintained at approximately constant levels. This allows the internal structure to be maintained even if unintended external pressure is applied during use, thus suppressing the possibility of, for example, kinking of the fluid 91 flow path.

[0125] As shown in Figure 11, the medical reservoir 3E comprises a lid 314 and a main body 315. The lid 314 is attached to the upper part of the main body 315 and covers the upper part of the main body 315. The lid 314 has a first chamber 31E, a partition wall 33E, a one-way valve 34, a first pressure release section 36E, and a second pressure release section 36F. The first chamber 31E is formed in a substantially cylindrical shape. The partition wall 33E is attached to the lower part of the first chamber 31E and covers the lower part of the first chamber 31E.

[0126] Furthermore, the main body 315 has a container shape with an internal space. The internal space of the main body 315, excluding the space of the first chamber 31E partitioned by a partition wall 33E, etc., substantially corresponds to the second chamber 32E. At this time, the lid 314 is configured to be detachably attached to the main body 315. When the lid 314 is attached to the main body 315, it is preferable that liquid tightness be ensured between the lid 314 and the main body 315 in order to prevent the fluid 92 present in the second chamber 32E from leaking out from the contact area between the lid 314 and the main body 315, and to prevent foreign matter such as bacteria and viruses from entering from the outside.

[0127] There are no particular restrictions on the configuration for ensuring liquid tightness between the lid 314 and the main body 315. For example, a rubber sealing member may be provided on at least one of the contact portions of the lid 314 and the main body 315. This prevents the fluid contained inside the medical reservoir 3E from leaking to the outside through the contact portion between the lid 314 and the main body 315. In the medical reservoir 3E shown in Figure 11, the lid 314 is configured to cover the opening area above the main body 315, but the assembly method is not limited to this.

[0128] Furthermore, as shown in Figure 11, in the medical reservoir 3E according to the fifth modified example, the first chamber 31E is configured to be attached to the lid 314, but is configured to receive the fluid 91 flowing in from the inlet 311 in a liquid-tight state. As long as the direction of fluid movement is restricted to the order from the inlet 311 to the first chamber 31E, the one-way valve 34, and the second chamber 32E, the mounting position of the first chamber 31E inside the medical reservoir 3E is not particularly limited. For example, the partition wall 33E may be attached so as to protrude inward from the side wall of the main body 315, thereby partitioning a part of the space of the main body 315 and forming the first chamber 31E.

[0129] Furthermore, there are no particular restrictions on the position or shape of the partition wall 33E. For example, similar to the medical reservoir 3C according to the third modified example (see Figure 8), the partition wall 33E may be tapered so that the internal space of the first chamber 31E gradually decreases toward the one-way valve 34. With this configuration, the fluid 91 contained in the first chamber 31E is more likely to concentrate toward the one-way valve 34, thereby suppressing excessive fluid stagnation in the cerebrospinal fluid circulation circuit 2.

[0130] The first pressure release section 36E includes a first pressure release conduit 365 and a first pressure release filter 366. The first pressure release conduit 365 is provided above the first chamber 31E, protruding upward from the upper surface of the lid 314. The inside of the first chamber 31E is connected to the outside of the first chamber 31E (i.e., the outside of the medical reservoir 3E) via a first outlet 324 formed inside the first pressure release conduit 365.

[0131] The first pressure relief conduit 365 houses and fixes the first pressure relief filter 366. Specifically, as shown in Figure 11, the first pressure relief filter 366 is installed inside the first pressure relief conduit 365 and fixed to the inner wall of the first pressure relief conduit 365 with an adhesive or the like. A specific example of the first pressure relief filter 366 is the same as the specific example of the pressure relief filter 364 described above with respect to Figure 8. This makes it possible to suppress the risk of bacteria and viruses mixing into the fluid 91 stored inside the first chamber 31E. Note that the method of fixing the first pressure relief filter 366 in the first pressure relief conduit 365 is not limited to adhesive; for example, it may be fixed mechanically without using adhesive.

[0132] As shown by arrow A56 in Figure 11, the first pressure release filter 366 releases the gas inside the first chamber 31E to the outside of the first chamber 31E through a gap formed in the first pressure release filter 366 itself. At this time, since the medical reservoir 3E according to this modified example is made of a hard resin material that undergoes minimal change in external shape due to fluctuations in internal pressure, there is a possibility that the internal pressure may rise excessively when fluid 91 is introduced into the first chamber 31E. In response to this, the first chamber 31E is equipped with the first pressure release filter 366 of the first pressure release section 36E, which releases the gas inside to the outside, thereby maintaining the internal pressure of the first chamber 31E below a predetermined pressure. The configuration of the first pressure release section 36E is not particularly limited as long as it maintains the internal pressure of the first chamber 31E below a predetermined pressure, and the movement of gas from the outside to the inside in accordance with the internal pressure of the first chamber 31E is also permitted.

[0133] The second pressure release section 36F includes a second pressure release conduit 367 and a second pressure release filter 368. The second pressure release conduit 367 is provided above the second chamber 32E, which is located in the main body 315, and protrudes upward from the upper surface of the lid 314. The inside of the second chamber 32E is connected to the outside of the second chamber 32E (i.e., the outside of the medical reservoir 3E) via a second outlet 325 formed inside the second pressure release conduit 367.

[0134] The second pressure relief conduit 367 houses and fixes the second pressure relief filter 368. Specifically, as shown in Figure 11, the second pressure relief filter 368 is installed inside the second pressure relief conduit 367 and fixed to the inner wall of the second pressure relief conduit 367 with an adhesive or the like. A specific example of the second pressure relief filter 368 is the same as the specific example of the pressure relief filter 364 described above with respect to Figure 8. This reduces the risk of bacteria and viruses contaminating the fluid 92 stored inside the second chamber 32E. Note that the method of fixing the second pressure relief filter 368 in the second pressure relief conduit 367 is not limited to adhesive; for example, it may be fixed mechanically without using adhesive.

[0135] As shown by arrow A57 in Figure 11, the second pressure release filter 368 releases the gas inside the second chamber 32E to the outside of the second chamber 32E through a gap formed in the second pressure release filter 368 itself. At this time, since the medical reservoir 3E according to this modified example is made of a hard resin material that undergoes minimal change in external shape due to fluctuations in internal pressure, there is a possibility that the internal pressure may rise excessively when oxygen is added by bubbling inside the second chamber 32E to generate fluid 92. In response to this, the second chamber 32E is equipped with the second pressure release filter 368 of the second pressure release section 36F, which releases the gas inside to the outside, thereby maintaining the internal pressure of the second chamber 32E below a predetermined pressure. The configuration of the second pressure release section 36F is not particularly limited as long as it maintains the internal pressure of the second chamber 32E below a predetermined pressure, and the movement of gas from the outside to the inside in accordance with the internal pressure of the second chamber 32E is also permitted.

[0136] As shown by arrow A29 in Figure 11, oxygen supplied from the oxygen supply source 82 (see Figure 1) passes through the outlet 321 and is supplied into the second chamber 32E, where it is introduced as bubbles into the fluid 91 contained in the second chamber 32E via the one-way valve 34 from the first chamber 31E. As a result, the fluid 91, which is cerebrospinal fluid discharged outside the body through the first conduit 41, becomes oxygenated cerebrospinal fluid (i.e., a highly oxygenated solution) and is generated as fluid 92 in the second chamber 32E. This is as described above with respect to Figure 8. The other structures are the same as those of the medical reservoir 3 described above with respect to Figure 5.

[0137] As explained above, the medical reservoir 3E in this modified example is made of a hard resin material. In this case, it may be difficult to release the pressure inside the first chamber 31E that rises with natural drainage. If this occurs, the cerebrospinal fluid circulation circuit 2 according to this embodiment is a system that circulates the fluid containing cerebrospinal fluid by injecting fluid into the body cavity where the subject's cerebrospinal fluid is present and pushing the fluid present in the body cavity out of the body cavity due to intracranial pressure, thereby allowing the fluid to drain naturally. If the pressure inside the first chamber 31E rises excessively, the pressure gradient between the intracranial pressure and the internal pressure of the first chamber 31E may decrease or disappear. As a result, the amount of fluid containing cerebrospinal fluid discharged outside the body (i.e., the amount of drainage) decreases, and the amount of fluid injected by the cerebrospinal fluid circulation circuit 2 becomes relatively excessive compared to the amount discharged, which may lead to an increase in intracranial pressure. Furthermore, if the pressure inside the first chamber 31E rises excessively, this excessive pressure may be transmitted to the body cavity containing cerebrospinal fluid, which is fluidly connected to the first chamber 31E via the drainage catheter 51 and the first conduit 41.

[0138] In contrast, the medical reservoir 3E according to this modified example is made of a rigid resin material that minimizes changes in its external shape even when the pressure inside the container rises, and further includes not only a second pressure release section 36F for maintaining the pressure inside the second chamber 32E below a predetermined pressure, but also a first pressure release section 36E for maintaining the pressure inside the first chamber 31E below a predetermined pressure. Therefore, the medical reservoir 3E according to this modified example suppresses changes in internal volume and overall shape due to changes in the pressure inside the container, and can maintain the pressure inside the first chamber 31E, which rises with natural drainage, below a predetermined pressure. Consequently, it is possible to prevent the pressure inside the first chamber 31E from rising excessively, thereby preventing a decrease in the amount of fluid drained, including cerebrospinal fluid, and preventing the transmission of excessive pressure into the body. In other words, it is possible to reduce the risk of cerebrospinal fluid reflux and the resulting increase in intracranial pressure (for example, the development of hypertension).

[0139] Next, the connector 6 of this embodiment will be described with reference to the drawings. Figure 12 is a cross-sectional view showing the connector of this embodiment. The connector 6 of this embodiment is capable of connecting the upstream end 411 of the first conduit 41 to the discharge catheter 51 and is capable of receiving the injection catheter 52. The connector 6 has a first holding portion 61, a second holding portion 62, and an outlet portion 63.

[0140] The first retaining portion 61 has a first sealing portion 611. The inner diameter of the first sealing portion 611 is less than or equal to the outer diameter of the discharge catheter 51. The first retaining portion 61 holds the discharge catheter 51, which is inserted from the first insertion port 612 in the direction of arrow A33 shown in Figure 12, at the first sealing portion 611. The first sealing portion 611 has a first tapered portion 613. The first tapered portion 613 is a portion in which the inner diameter gradually decreases in the direction in which the discharge catheter 51 is inserted from the first insertion port 612 (i.e., in the direction of arrow A33). Because the first sealing portion 611 has a first tapered portion 613, the discharge catheter 51 is reliably and liquid-tightly sealed to the first tapered portion 613 of the first sealing portion 611. As a result, the discharge catheter 51 can be fixed inside the first retaining portion 61.

[0141] The second retaining portion 62 has a second sealing portion 621. The inner diameter of the second sealing portion 621 is less than or equal to the outer diameter of the injection catheter 52. The second retaining portion 62 holds the injection catheter 52, which is inserted from the second insertion port 622 in the direction of arrow A34 shown in Figure 12, at the second sealing portion 621. The second sealing portion 621 has a second tapered portion 623. The second tapered portion 623 is the part in which the inner diameter gradually decreases in the direction in which the injection catheter 52 is inserted from the second insertion port 622 (i.e., the direction of arrow A34). Because the second sealing portion 621 has a second tapered portion 623, the injection catheter 52 is reliably and liquid-tightly sealed to the second tapered portion 623 of the second sealing portion 621.

[0142] The outlet portion 63 is sandwiched between the first holding portion 61 and the second holding portion 62 and fixed to the first holding portion 61 and the second holding portion 62. The first holding portion 61, the second holding portion 62 and the outlet portion 63 may be formed integrally, or they may be formed separately and joined together.

[0143] The outlet section 63 has a channel 631 through which cerebrospinal fluid passing through the space 53 flows. As described above with respect to Figure 1, the cerebrospinal fluid passing through the space 53 is the cerebrospinal fluid that has passed through the outlet 511 of the drainage catheter 51 and been aspirated into the space 53. As shown by arrow A35 in Figure 12, the cerebrospinal fluid that has flowed through the channel 631 is discharged from the outlet 632 provided in the outlet section 63 and flows through the first conduit 41 to, for example, the first chamber 31 of the medical reservoir 3.

[0144] When viewed along the direction of the axis A31 of the discharge catheter 51 held in the first holding part 61 or the direction of the axis A32 of the infusion catheter 52 held in the second holding part 62, the second contact part 621 is located inside the first contact part 611. As shown in Figure 12, the infusion catheter 52 inserted from the second insertion port 622 can be inserted into the lumen 513 of the discharge catheter 51 fixed to the first holding part 61, and can penetrate the discharge catheter 51. Then, as shown by arrow A36 in Figure 12, the hyperoxygenated solution is injected into the subarachnoid space where cerebrospinal fluid is present through the lumen 523 of the infusion catheter 52. On the other hand, as shown by arrow A35 in Figure 12, the cerebrospinal fluid discharged from the proximal end 514 of the discharge catheter 51 fixed to the first holding part 61 passes through the flow path 631 of the outlet part 63 and is discharged from the outlet 632 toward the first conduit 41.

[0145] As described above, the connector 6 of this embodiment can connect the upstream end 411 of the first conduit 41 to the discharge catheter 51 and can accept the injection catheter 52. As a result, the cerebrospinal fluid circulation circuit 2 described above in Figure 1 can be simplified in structure.

[0146] Next, specific examples of the connector 6 and connector fastener 7 of this embodiment will be described with reference to the drawings. Figure 13 is a perspective view showing specific examples of the connector and connector fastener of this embodiment. As shown in Figure 13, the connector 6 of this embodiment is fixed to the patient's body surface by a connector fastener 7 that is attached to a suitable location on the patient's body surface. The connector fastener 7 has a fastener body 71 and a tube holding portion 72.

[0147] The fixing device body 71 has a body surface attachment portion 711 and a connector attachment portion 712. As shown in Figure 13, the body surface attachment portion 711 is plate-shaped and is attached to the patient's body surface. The connector attachment portion 712 attaches the connector 6 to the fixing device body 71. In the connector fixing device 7 shown in Figure 13, the connector attachment portion 712 is a groove formed along the longitudinal direction D1 (see Figure 3) in the fixing device body 71.

[0148] For example, as shown in Figure 13, magnets 64 are attached to the lower surfaces of the first holding portion 61 and the second holding portion 62, respectively. The lower surfaces of the first holding portion 61 and the second holding portion 62 are surfaces facing the connector mounting portion 712. The connector 6 is attached to the connector mounting portion 712 by the magnets 64 being attracted to it. As shown by arrow A41 in Figure 13, the connector mounting portion 712 can adjust the mounting position of the connector 6 along the direction of the axis A31 of the discharge catheter 51 held in the first holding portion 61 and the direction of the axis A32 of the infusion catheter 52 held in the second holding portion 62.

[0149] As shown in Figure 13, the tube holder portion 72 is fixed to the tip of the fixing device body 71 and can hold the drainage catheter 51. For example, the portion of the tube holder portion 72 that holds the drainage catheter 51 has a groove formed therein that has approximately the same diameter as the outer diameter of the drainage catheter 51. The tube holder portion 72 also has a curved portion 721 provided in the part that comes into contact with the drainage catheter 51. As a result, the tube holder portion 72 can prevent the drainage catheter 51 from kinking (breaking, etc.) near the puncture site 515.

[0150] In this specific example, the connector fixing device 7 allows the connector mounting portion 712 to adjust the mounting position of the connector 6 along the direction of the axis A31 of the drainage catheter 51 held by the first holding portion 61 and the direction of the axis A32 of the infusion catheter 52 held by the second holding portion 62. Therefore, the connector fixing device 7 can be fixed to the patient's body surface at any position within a certain range along the direction of the axis A31 of the drainage catheter 51 from the position where the drainage catheter 51 is inserted into the subarachnoid space (i.e., the puncture site 515), regardless of the length to which the drainage catheter 51 is inserted into the subarachnoid space. This prevents the drainage catheter 51 from kinking or falling out.

[0151] Furthermore, in the specific example of the connector 6 shown in Figure 13, the first holding portion 61 has a first clamping portion 614. As shown by arrow A42 in Figure 13, the first clamping portion 614 is rotatably supported with respect to a first support shaft 615 provided on the first holding portion 61. The first clamping portion 614 clamps and fixes the discharge catheter 51 by rotating in a closing direction relative to the first holding portion 61. The second holding portion 62 also has a second clamping portion 624. As shown by arrow A43 in Figure 13, the second clamping portion 624 is rotatably supported with respect to a second support shaft 625 provided on the second holding portion 62. The second clamping portion 624 clamps and fixes the infusion catheter 52 by rotating in a closing direction relative to the second holding portion 62.

[0152] As a result, after the infusion catheter 52 is positioned in the lumen 513 of the drainage catheter 51 and moves through the lumen 513 of the drainage catheter 51, the connector 6 can fix the positions of the drainage catheter 51 and the infusion catheter 52. This allows the connector 6 to adjust and fix the infusion position of the hyperoxygenated solution by the infusion catheter 52 and the drainage position (i.e., aspiration position) of the cerebrospinal fluid by the drainage catheter 51.

[0153] Embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. The configurations of the above embodiments can be partially omitted or combined in any way different from those described above.

[0154] 2: Cerebrospinal fluid circulation circuit, 3: Medical reservoir, 3A: Medical reservoir, 3B: Medical reservoir, 3C: Medical reservoir, 3D: Medical reservoir, 3E: Medical reservoir, 5: Medical device, 6: Connector, 7: Connector fixing device, 31: First chamber, 31A: First chamber, 31C: First chamber, 31D: First chamber, 31E: First chamber, 32: Second chamber, 32A: Second chamber, 32E: Second chamber, 33: Partition, 33C: Partition, 33D: Partition, 33E: Partition, 33A: Flow path, 34: One-way valve, 34B: One-way valve, 35: Gas introduction section, 35A: Gas introduction section, 35B: Gas introduction section, 36: Pressure release section, 36B: Pressure release section, 36E: First pressure release section, 36F: Second pressure release section, 37: Inner surface, 38: Outer surface, 39: Fixing device, 41: First conduit, 42: Second conduit, 43: Third conduit, 44: Fourth conduit, 45: Branch pipe, 46: Branch pipe, 51: Discharge catheter, 52: Infusion catheter, 53: Space, 61: First holding section, 62: Second holding section, 63: Outlet section, 64: Magnet, 71: Fixing device body, 72: Tube holding section, 81: Artificial cerebrospinal fluid bag, 82: Oxygen supply source, 83: Filter, 84: Fluid delivery pump, 85: Air trap, 86: Connector, 91: Fluid, 92: Fluid, 311: Inlet, 312: Inlet, 313: First flow path inlet, 314: Cover, 315: Main body, 321: Outlet, 322: Discharge port, 323: Second flow path inlet, 324: First discharge port, 325: Second discharge port, 331: Flow path, 351: Ventilation port, 352: Exhaust port, 361: Pressure relief conduit, 362: Pressure relief valve, 363: Air guide section, 364: Pressure relief filter, 365: First pressure relief conduit, 366: First pressure relief filter, 367: Second pressure relief conduit, 368: Second pressure relief filter, 371: First tube connector, 372: Second tube connector, 373: Third tube connector, 374: Fourth tube connector, 391: First pressure relief conduit, 392: Second pressure relief conduit, 393: First space, 394: Second space, 395: Inner wall, 396: Hook, 411: Upstream end, 412: Downstream end, 421: Upstream end, 422: Downstream end, 423: First pump mounting section, 424: Second pump mounting section, 511: Outlet, 513: Lumen,514: Proximal end, 515: Puncture site, 521: Inlet, 523: Lumen, 611: First contact section, 612: First insertion port, 613: First tapered section, 614: First clamping section, 615: First support shaft, 621: Second contact section, 622: Second insertion port, 623: Second tapered section, 624: Second clamping section, 625: Second support shaft, 631: Flow path, 632: Outlet, 711: Body surface attachment section, 712: Connector attachment section, 721: Curved section, 811: Artificial cerebrospinal fluid, 861: First pressure measuring section, 862: Second pressure measuring section

Claims

1. A medical reservoir comprising: a first chamber having an inlet for introducing fluid from the outside to the inside; a second chamber having an outlet for discharging the fluid from the inside to the outside; at least one flow path provided between the first chamber and the second chamber and connecting the first chamber and the second chamber; and a one-way valve provided in the flow path for allowing the movement of the fluid from the first chamber to the second chamber while preventing the movement of the fluid from the second chamber to the first chamber, wherein the only passage through which the fluid can move between the first chamber and the second chamber is the flow path provided with the one-way valve.

2. The medical reservoir according to claim 1, further comprising a gas introduction section provided in at least the second chamber for introducing a gas supplied from the outside into the fluid contained in the second chamber.

3. The medical reservoir according to claim 1, further comprising a pressure release section provided in the second chamber for maintaining the internal pressure of the second chamber below a predetermined pressure.

4. The medical reservoir according to claim 1, characterized in that at least one of the first chamber and the second chamber has an inlet for introducing a therapeutic fluid from the outside to the inside.

5. The medical reservoir according to claim 1, characterized in that the one-way valve opens at a pressure of 5 mmHg or less.

6. The medical reservoir according to claim 1, characterized in that the one-way valve is an umbrella valve or a duckbill valve.

7. A cerebrospinal fluid circulation circuit comprising: a medical reservoir as described in claim 1; a first conduit having a first end that can be inserted into a containment cavity in a living body where cerebrospinal fluid is present and connectable to a drainage catheter for draining the cerebrospinal fluid outside the living body, and a second end that is connected to the inlet of the medical reservoir; and a second conduit having a third end that is connected to the outlet of the medical reservoir and a fourth end that can be inserted into the containment cavity and connectable to an injection catheter for injecting the fluid into the containment cavity.

8. The cerebrospinal fluid circulation circuit according to claim 7, further comprising a connector that can connect the first end to the discharge catheter and can accept the injection catheter.

9. The cerebrospinal fluid circulation circuit according to claim 7, characterized in that the second conduit has a pump attachment portion connected to a fluid delivery pump that delivers the fluid toward the living body.

10. The cerebrospinal fluid circulation circuit according to claim 9, further comprising a pressure measuring unit for measuring the pressure inside the second conduit between the pump mounting unit and the fourth end.

11. A cerebrospinal fluid circulation circuit comprising: a medical reservoir according to claim 1 for performing therapeutic treatment on cerebrospinal fluid; an outlet catheter that can be inserted into a containment cavity in a living body where the cerebrospinal fluid is present and for discharging the cerebrospinal fluid outside the living body; a first conduit having a first end connectable to the outlet catheter and a second end connectable to the inlet of the medical reservoir; an injection catheter that can be inserted into the containment cavity and for injecting the fluid into the containment cavity; and a second conduit having a third end connectable to the outlet of the medical reservoir and a fourth end connectable to the injection catheter.

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