Suction system and method for controlling a suction system

Abstract

To suck liquid from a patient by using fewer suction sources when a suction system uses a plurality of suction paths.SOLUTION: A suction system 100 which has suction pressure with which liquid is sucked from a patient operate on a plurality of suction paths, includes: a closing part 20 closing each of the plurality of suction paths; and a control part 19 which controls the closing part so that it opens one of the plurality of suction paths, closes the rest of the plurality of suction paths, then opens another suction path different from one of the rest of the suction paths, and closes the other suction paths including the one suction path of the plurality of suction paths.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a suction system that sequentially opens a plurality of suction paths in a predetermined order, and a method for controlling the suction system. [Background technology]

[0002] Patent Document 1 discloses an aspirator for aspirating saliva that applies suction pressure to a suction flow path. This aspirator includes a pump means for generating suction pressure and a pressure adjusting means for adjusting the suction pressure. The aspirator also includes a control means for controlling the operation of the pressure adjusting means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-144060 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention is directed to providing an aspiration system that utilizes multiple aspiration paths, allowing fluid to be aspirated from a patient using fewer suction sources. [Means for solving the problem]

[0005] An aspiration system according to one aspect of the present invention is an aspiration system that applies a suction pressure to a plurality of aspiration paths to suck liquid from a patient, and includes a closing unit that closes each of the plurality of aspiration paths, and a control unit that controls the closing unit to open one of the plurality of aspiration paths and close the remaining suction paths of the plurality of aspiration paths, and then open another suction path of the remaining suction paths that is different from the one suction path, and close the other suction paths of the plurality of aspiration paths including the one suction path.

[0006] Furthermore, a suction system control method according to one aspect of the present invention is a control method for a suction system that applies suction pressure to multiple suction paths to suck liquid from a patient and has a closing unit that closes each of the multiple suction paths, and controls the closing unit to open one of the multiple suction paths and close the remaining suction paths of the multiple suction paths, and then open another suction path of the remaining suction paths that is different from the one suction path and close the other suction paths of the multiple suction paths including the one suction path. [Effects of the Invention]

[0007] This allows for fewer suction sources to be used to aspirate fluid from the patient when the aspiration system utilizes multiple aspiration paths. [Brief explanation of the drawings]

[0008] [Figure 1] Schematic of the aspiration system with the first drainage tube open. [Figure 2] Schematic of the aspiration system with the second drainage tube open. [Figure 3] FIG. 4 is a schematic explanatory diagram of the operation of a cam mechanism. [Figure 4] 10 is a schematic flowchart of a suction process. [Figure 5] FIG. 6 is a schematic diagram of a suction system according to a second embodiment. [Figure 6] FIG. 4 is a schematic explanatory diagram of the operation of a solenoid mechanism. [Figure 7] FIG. 10 is a schematic diagram of a first suction path in the suction system according to the third embodiment. [Figure 8] FIG. 11 is a schematic diagram of a second suction path in the suction system according to the third embodiment. [Figure 9] FIG. 11 is a schematic diagram of a third suction path in the suction system according to the third embodiment. [Figure 10] FIG. 4 is a schematic explanatory diagram of the operation of a first cam. [Figure 11]1A is a schematic cross-sectional view of the first to third cams, where A shows the state where the rotation angle is 0°, B shows the state where the rotation angle is 60°, and C shows the state where the rotation angle is 180°. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of components described in the following embodiments can be arbitrarily set and can be changed depending on the configuration of the device to which the present invention is applied or various conditions. Furthermore, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below. [Example]

[0010] The saliva drainage tube can be used for patients who cannot swallow saliva on their own, such as patients with amyotrophic lateral sclerosis (ALS), muscular dystrophy, Parkinson's disease, Alzheimer's disease, or impaired consciousness, or disabled children. For example, to prevent aspiration pneumonia, a continuous low negative pressure suction system, which is an example of the suction system 100, can utilize a saliva drainage tube placed in the patient's oral cavity. For example, a wire is inserted into the inner diameter of the saliva drainage tube, and by bending this wire, the shape of the wire can be adjusted to fit the shape of the patient's oral cavity. However, simply bending the wire can sometimes make it difficult to adequately adjust the shape of the wire to the shape of the patient's oral cavity.

[0011] The tip of the saliva drainage tube that suctions saliva is preferably positioned in a location in the patient's oral cavity where saliva tends to accumulate. However, due to the patient's tongue or body movements, it may be difficult to keep the tip in the appropriate location in the patient's oral cavity. Furthermore, the location where saliva tends to accumulate varies from patient to patient and also depending on the patient's posture. Furthermore, each patient may have multiple locations where saliva tends to accumulate. Therefore, using multiple saliva drainage tubes allows for efficient suction of saliva. For example, saliva can be efficiently suctioned even if the tip moves within the oral cavity or there are multiple locations where saliva tends to accumulate.

[0012] [First embodiment] Referring to Figures 1 to 4, a suction system 100 that applies suction pressure to multiple suction paths to aspirate liquid from a patient will be described. Figure 1 is a schematic diagram showing the suction system 100 with the first drainage tube 11 open. In the state shown in Figure 1, the second drainage tube 12 is closed, and saliva is aspirated through the first drainage tube 11. Figure 2 is a schematic diagram showing the suction system 100 with the second drainage tube 12 open. In the state shown in Figure 2, the first drainage tube 11 is closed, and saliva is aspirated through the second drainage tube 12. Figure 3 is an explanatory diagram illustrating the change in the rotation angle of the cam 21 over time, where the vertical axis represents the rotation angle from the start of rotation of the cam 21 and the horizontal axis represents the elapsed time from the start of rotation of the cam 21. Figure 4 is a flowchart illustrating the suction process.

[0013] As shown in FIG. 1, the suction system 100 includes, as examples of multiple suction paths, a first suction path including a first drainage tube 11 and a suction tube 16, and a second suction path including a second drainage tube 12 and a suction tube 16. For example, the suction path is a path on which suction pressure from a suction unit acts, and has a flow path through which a liquid or a gas such as air flows. The suction system 100 also includes a pump 15 as an example of a suction unit that generates suction pressure to act on the first suction path and the second suction path. The pump 15 is connected to each of the multiple suction paths. In the following description, the first suction path and the second suction path may be collectively referred to simply as suction paths.

[0014] The first drainage tube 11 and the second drainage tube 12 have internal flow paths through which saliva, an example of a liquid to be aspirated, flows. The suction tube 16 has a flow path through which air flows so that a suction pressure corresponding to the negative pressure (or negative pressure) generated by the pump 15 acts on the suction path, and a suction pressure corresponding to the flow rate of the flowing air acts on the suction path. The first drainage tube 11 and the second drainage tube 12 are connected to a suction system 100. The distal ends of the first drainage tube 11 and the second drainage tube 12 are placed in the patient's oral cavity. It is preferable that the respective distal ends are placed in different positions in the oral cavity. However, the distal ends may be placed adjacent to each other so as to aspirate saliva from the same position in the oral cavity. The first drainage tube 11 and the second drainage tube 12 are configured to be detachable from the suction system 100. The suction system 100 may also include the first drainage tube 11 and the second drainage tube 12. In this case, the first drainage tube 11 and the second drainage tube 12 may be configured integrally as part of the suction system 100.

[0015] The suction system 100 suctions saliva, an example of a liquid, from the oral cavity, an example of a patient's body. The saliva suctioned by the suction system 100 flows through the internal flow paths of the first drainage tube 11 and the second drainage tube 12. The number of suction paths is not limited to two and may be three or more. In this case, the number of pumps 15 is less than the number of suction paths. That is, it is sufficient that two or more suction paths are connected to at least one pump 15. Furthermore, when there are three or more suction paths, another suction path including a drainage tube that is not closed by the cam mechanism 20 may be connected to the pump 15.

[0016] The suction system 100 also includes a cam mechanism 20 as an example of a closing unit that closes each of the multiple suction paths. The cam mechanism 20 has a cam 21, which is an example of a rotating body. The cam 21 compresses and closes each of the first drainage tube 11 and the second drainage tube 12, which are examples of portions of each of the multiple suction paths. The cam mechanism 20 also includes a motor 22 that rotates the cam 21. Examples of the motor 22 include a DC motor, an AC motor, an ultrasonic motor, or the like. A rotation transmission mechanism including a shaft, gears, and the like (not shown) may be provided between the motor 22 and the cam 21. In this case, the rotational force from the motor 22 is transmitted to the cam 21 via the rotation transmission mechanism.

[0017] In the example of FIG. 1, the cam 21 is shown by a solid line when the rotation angle is 0° at the start of rotation, and by a dashed line when the rotation angle is 90° after the start of rotation. Here, the rotation angle is the angle formed by the line segment connecting the position VP' to the rotation center CP of the cam 21 and the line segment connecting the position VP to the rotation center CP. Position VP' is the position of the vertex on the circumference of the base circle of the cam 21 at the start of rotation, which is an example of a reference point. Position VP is the position of the vertex on the circumference of the base circle of the cam 21 during rotation. Note that the reference point may be on the circumference of the base circle and does not have to be the vertex of the cam 21. Furthermore, although the cam 21 shown in FIG. 1 has a substantially semicircular shape, it may have other shapes, such as a teardrop shape.

[0018] When the cam 21 is rotated by the motor 22, the first drainage tube 11 and the second drainage tube 12 that are in contact with the cam 21 are sandwiched and compressed by the cam 21 and the compression unit 23. This causes the internal flow paths to be crushed, and the first drainage tube 11 and the second drainage tube 12 are closed. Therefore, in the crushed drainage tubes, the flow of saliva is obstructed and suction stops. In the example of FIG. 1 , the second drainage tube 12 is compressed by the cam 21 shown by the solid line, and suction of saliva through the second drainage tube 12 is stopped. On the other hand, the internal flow path of the first drainage tube 11 that is not compressed by the cam 21 is not crushed. Therefore, the flow of saliva is not obstructed, and saliva is suctioned through the first drainage tube 11 in the direction indicated by the arrow DA.

[0019] When the outer peripheral surface of the rotating cam 21 moves in a direction away from the compression unit 23, the first drainage tube 11 and the second drainage tube 12 each return to their original shape due to their own elasticity. As a result, the internal flow path also returns to its original shape, and the obstruction to the flow of saliva is released, allowing saliva to be suctioned. In the example of FIG. 1 , the outer peripheral surface of the cam 21 moves in a direction away from the compression unit 23 depending on the rotation angle, and in the state indicated by the dashed line where the rotation angle is 90°, the second drainage tube 12 returns to its original shape. Therefore, the obstruction to the flow of saliva is released, and saliva is suctioned via the second drainage tube 12. Note that the internal flow path does not need to be completely crushed as long as the amount of saliva flowing is extremely small and the flow is substantially obstructed.

[0020] Furthermore, the suction system 100 includes a pump 15 as an example of a suction unit that generates suction pressure acting on the multiple suction paths. The suction pressure suitable for suctioning saliva varies depending on the viscosity of the saliva being suctioned. However, even when the viscosity of saliva is high, it is considered that the suction pressure will not exceed the viscosity of phlegm. Therefore, the suction pressure acting on the first drainage tube 11 and the second drainage tube 12 is set within a range of, for example, a maximum negative pressure of -20 kP to a minimum negative pressure of -2 kP. The suction paths are also provided with a saliva tank 17 as an example of a liquid tank for storing saliva. In the example of FIG. 1 , the saliva tank 17 is disposed between the first drainage tube 11 and the second drainage tube 12 and the suction tube 16. The first drainage tube 11 and the second drainage tube 12 are connected to the saliva tank 17. That is, the pump 15 is connected to the first drainage tube 11 and the second drainage tube 12 via the suction tube 16 and the saliva tank 17. The saliva sucked through the first drainage tube 11 and the second drainage tube 12 is collected in the saliva reservoir 17.

[0021] [Suction Order] By using multiple suction paths, the tip of each drainage tube can be positioned at each of multiple locations in the oral cavity where saliva is likely to accumulate. Here, if multiple drainage tubes are simultaneously suctioned using a single pump 15 at a sustained low suction pressure (or low negative pressure), some drainage tubes will have difficulty suctioning saliva compared to other drainage tubes. That is, the suction resistance of drainage tubes located in locations where saliva is more likely to accumulate is greater than that of drainage tubes located in locations where saliva is less likely to accumulate. Therefore, drainage tubes located in locations where saliva is more likely to accumulate and where a larger amount of saliva has accumulated will have relatively more difficulty suctioning saliva.

[0022] However, if a different pump 15 is connected to each of the multiple suction paths to adjust the suction pressure, multiple pumps 15 must be provided. This increases the size and cost of the suction system 100. Therefore, the suction system 100 of this embodiment alternately closes and opens the multiple suction paths using fewer pumps 15. This prevents the occurrence of drainage tubes that make it difficult to suction saliva. At the same time, the size and cost of the suction system 100 are prevented from increasing.

[0023] Specifically, any one of the multiple suction paths connected to one pump 15 is opened to communicate with the pump 15. Then, all other suction paths are closed to prevent communication with the pump 15. After a predetermined time has elapsed, any one of the closed suction paths is opened to connect with the pump 15. Then, all other suction paths are closed to prevent communication with the pump 15. After a predetermined time has elapsed, any one of the closed suction paths excluding the suction path that was opened earlier is opened to connect with the pump 15. Then, all other suction paths are closed to prevent communication with the pump 15. In the same manner, the suction paths that are opened are alternated in sequence, and saliva is sucked from any one of the suction paths.

[0024] 1 and 2, the suction system 100 includes a control unit 19 that controls the cam mechanism 20. As an example, the control unit 19 is a computer having a processor (not shown) and a memory serving as a computer-readable non-transitory storage medium storing a control program. The processor is, for example, a central processing unit (CPU) or a micro-processing unit (MPU), and controls the entire suction system 100, including the cam mechanism 20 and the pump 15, based on a program stored in the memory, and also comprehensively controls various processes. The memory includes a random access memory (RAM), which is a system work memory for the processor to operate, as well as a read-only memory (ROM) for storing programs and system software, and storage devices such as a hard disk drive (HDD) and a solid state drive (SSD).

[0025] Furthermore, the control unit 19 can also perform control according to a program stored in a portable recording medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), a CF (Compact Flash) card, or a USB (Universal Serial Bus) memory, or an external storage medium such as a server on the Internet. The control unit 19 may also control the operation of the pump 15 based on the flow rate and suction pressure output by a flow rate sensor and a pressure sensor (not shown), respectively. As an example, the flow rate sensor and the pressure sensor are provided in the saliva tank 17. The flow rate of saliva to be aspirated is preferably set or controlled to a necessary and sufficient flow rate. For example, when aspirating saliva from a patient who cannot swallow saliva, the patient often does not close their mouth. If the patient's mouth is not closed, a high flow rate of aspirated saliva can dry out the patient's mouth. Therefore, the flow rate of aspirated saliva is set to a maximum flow rate of 10 L / min or less. The control unit 19 may be implemented as a hardware circuit or as a logic device combining computer hardware and software.

[0026] The control unit 19 controls the cam mechanism 20 to open one of the first suction path including the first drainage tube 11 and the second suction path including the second drainage tube 12, and close the other suction path, which is the remaining suction path, of the first and second suction paths. For example, the control unit 19 controls the rotation speed of the cam 21 of the cam mechanism 20. Thereafter, the control unit 19 controls the cam mechanism 20 to open another suction path, which is different from the one suction path that was previously opened, of the remaining suction paths, and close the other suction paths, which includes the one suction path that was previously opened, of the first and second suction paths.

[0027] For example, as shown in Fig. 1, of the first drainage tube 11 and the second drainage tube 12, the cam mechanism 20 first opens the first drainage tube 11 of the first suction path and closes the remaining second drainage tube 12 of the second suction path. Note that the opening and closing do not have to start simultaneously, and there may be a time lag between them. Thereafter, the cam 21 rotates, and as shown in Fig. 2, the angle formed by the line segment connecting the apex position VP' at the start of rotation to the center of rotation CP and the line segment connecting the apex position VP of the rotating cam 21 to the center of rotation CP becomes 180°.

[0028] In this case, since the remaining suction path is one of the second suction paths, the cam mechanism 20 opens the second suction path as a separate suction path different from the previously opened first suction path. That is, the cam mechanism 20 opens the second drainage tube 12 of the second suction path. In addition, since the other first suction path is one of the first suction paths, the cam mechanism 20 closes the first suction path as another suction path including the previously opened first suction path. Note that the completion of the opening and the completion of the closing do not have to be simultaneous, and there may be a time lag between the two.

[0029] 2, the first drainage tube 11 is compressed by the cam 21, and the suction of saliva through the first drainage tube 11 is stopped. On the other hand, the internal flow path of the second drainage tube 12, which is not compressed by the cam 21, is not crushed. Therefore, the flow of saliva is not obstructed, and saliva is suctioned through the second drainage tube 12 in the direction indicated by the arrow DB.

[0030] The operation of the cam mechanism 20, which rotates once every 60 seconds, will be described in detail with reference to Figure 3. First, when the elapsed time from the start of rotation is 0 seconds, the rotation angle is 0°. At this time, the first drainage tube 11 is open and the second drainage tube 12 is closed. Then, when 15 seconds have passed and the rotation angle reaches 90°, both the first drainage tube 11 and the second drainage tube 12 are open. Thereafter, the first drainage tube 11 is closed, and only the second drainage tube 12 is open.

[0031] After 30 seconds have passed and the rotation angle is 180°, the second drainage tube 12 is open and the first drainage tube 11 is closed. After 45 seconds have passed and the rotation angle is 90°, both the first drainage tube 11 and the second drainage tube 12 are open. Thereafter, the second drainage tube 12 is closed and only the first drainage tube 11 is open. After 60 seconds have passed and the rotation angle is 0°, the first drainage tube 11 is open and the second drainage tube 12 is closed. Thereafter, the same opening and closing is repeated until the end of suction.

[0032] In the example of FIG. 3 , there is a state in which both the first drainage tube 11 and the second drainage tube 12 are open. Therefore, the time during which the first drainage tube 11 and the second drainage tube 12 are open during one rotation of the cam 21 is slightly longer than 30 seconds. Also, the time during which the first drainage tube 11 and the second drainage tube 12 are closed during one rotation of the cam 21 is shorter than 30 seconds. However, the state in which both the first drainage tube 11 and the second drainage tube 12 are open only lasts for a short time. Therefore, the impact on suction is small. Alternatively, the shape of the cam 21 may be changed so that there is a state in which both the first drainage tube 11 and the second drainage tube 12 are closed.

[0033] As one example, the control unit 19 opens one suction path after a predetermined time has elapsed since the opening of the other suction path. For example, the predetermined time is the time required for the cam 21 to rotate from 0° to 90°. In another example, the predetermined time is half the time required for the cam 21 to rotate once. The predetermined time may be changed depending on the shape of the cam 21, etc. Furthermore, the time from the opening of one suction path to the opening of the next suction path may be different for each of the multiple suction paths. For example, the time from the opening of the first suction path to the opening of the second suction path may be longer or shorter than the time from the opening of the second suction path to the opening of the first suction path.

[0034] Furthermore, the control unit 19 controls the cam mechanism 20 to open the plurality of suction paths in order. For example, when there is a first-opened path among the remaining suction paths, the control unit 19 controls the cam mechanism 20 to open another suction path from among the remaining suction paths, excluding the first-opened path. Furthermore, the control unit 19 controls the cam mechanism 20 to reopen the first-opened suction path after all the plurality of suction paths have been opened.

[0035] 1 as an example, when the first drainage tube 11 of the first suction path, of the first drainage tube 11 and the second drainage tube 12, is opened, the remaining suction path becomes the second suction path including the second drainage tube 12. Here, the second drainage tube 12 has not been opened first. Therefore, the second suction path is not excluded from the targets for opening, and the second suction path is opened as another suction path to be opened next after the first suction path. Furthermore, after both the first drainage tube 11 and the second drainage tube 12 have been opened, the first drainage tube 11 that was opened first is opened again.

[0036] In an example where there are three suction paths, when the first of the three suction paths is opened, two suction paths remain. Since the other two suction paths have not been opened previously, they are not excluded from the list of paths to be opened, and one of the two paths is opened as the next suction path to be opened. Next, when the second of the three suction paths is opened, the remaining two paths are the first and third suction paths. The first suction path is the path that was opened first. Therefore, the first suction path is excluded from the list of paths to be opened, and the third suction path is opened as the next suction path to be opened after the second suction path. Furthermore, after all three suction paths have been opened, the first suction path that was opened first is opened again.

[0037] The order in which the suction paths are opened may be set arbitrarily. For example, the order may be from left to right or from right to left of the lined up suction paths. Furthermore, the order may be in descending order of the size of the drainage tube, in descending order of the size of the liquid tank connected to the drainage tube, or in descending order of the amount of liquid stored in the liquid tank connected to the drainage tube. The order may also be random, or, if consecutive numbers are associated with each suction path, in descending order of the number.

[0038] [Suction processing] The suction process in the suction system 100 will be described with reference to the flowchart in Fig. 4. As an example, the suction process is started by a user operation to start suction and ended by a user operation to end suction. For example, the user operation is pressing a button provided on an operation unit of the suction system 100 or touching a button provided on a touch panel that is a display operation unit of the suction system 100.

[0039] When the user performs a user operation to start suction, the cam mechanism 20 opens the first drainage tube 11 of the first suction path, which is one of the multiple drainage tubes, and closes the second drainage tube 12 of the second suction path, which is the remaining suction path (S101). If one suction path is already open when suction starts, the cam mechanism 20 does not rotate to open it. Similarly, if the remaining suction path is already closed when suction starts, the cam mechanism 20 does not rotate to close it. Thereafter, if a predetermined time has not elapsed (NO in S102), the first drainage tube 11 continues to be opened and the second drainage tube 12 continues to be closed.

[0040] On the other hand, if a predetermined time has elapsed (YES in S102), the cam mechanism 20 opens the second drainage tube 12 of the second suction path, which is another suction path among the multiple suction paths, and closes the first drainage tube 11, which is the remaining cam mechanism 20 (S103). Thereafter, if the predetermined time has not elapsed (NO in S104), the first drainage tube 11 continues to be closed and the second drainage tube 12 continues to be opened. On the other hand, if the predetermined time has elapsed (YES in S104) and the user performs an operation to end suction (YES in S105), the suction process ends. If suction has not ended (NO in S105), the cam mechanism 20 again opens the first drainage tube 11, which is another suction path among the multiple suction paths, and again closes the second drainage tube 12, which is the remaining suction path (S103). Thereafter, one suction path is opened and the remaining suction paths are closed in sequence until suction ends.

[0041] According to the suction system 100 of the first embodiment described above, when multiple suction paths are used, liquid can be aspirated using fewer suction sources. Furthermore, even when multiple suction paths are connected to a single suction source, liquid can be aspirated efficiently. That is, the tip of each of the multiple drainage tubes can be positioned at multiple locations where saliva tends to accumulate. Furthermore, because saliva can be intermittently and reliably aspirated from each drainage tube, the frequency of periodic checks on the saliva accumulation status can be reduced. For example, at night when the patient is sleeping, the patient's caregiver or family member can move the tip of the drainage tube as needed to aspirate the patient's saliva. Therefore, it is necessary to periodically check the saliva accumulation status. In contrast, the suction system 100 reduces the likelihood of saliva accumulating in the oral cavity, thereby reducing the frequency of checks.

[0042] [Second embodiment] A second embodiment will be described with reference to Figures 5 and 6. The second embodiment differs from the first embodiment in that drainage fluid containing body fluids such as blood is aspirated from closed spaces such as the thoracic cavity and abdominal cavity. Figure 5 is a schematic diagram showing a suction system 200, and Figure 6 is an explanatory diagram of the operation of a solenoid mechanism 220. In the description of the second embodiment, differences from the first embodiment will be described, and components already described will be assigned the same reference numbers and their description will be omitted. Unless otherwise specified, components assigned the same reference numbers perform substantially the same operations and functions, and their effects are also substantially the same.

[0043] The suction system 200 includes a first suction path, a second suction path, and a third suction path as examples of multiple suction paths. The first suction path includes a first drainage tube 211 and a first suction tube 216A. The second suction path includes a second drainage tube 212 and a second suction tube 216B. The third suction path includes a third drainage tube 213 and a third suction tube 216C. Furthermore, the suction system 200 includes a suction device 215 as an example of a suction unit that generates suction pressure to act on the first suction path to the third suction path. The suction device 215 is connected to each of the multiple suction paths. In the following description, the first suction path to the third suction path may be collectively referred to simply as the suction paths. Furthermore, the first suction tube 216A, the second suction tube 216B, and the third suction tube 216C may be collectively referred to simply as the suction tubes 216.

[0044] Each of the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 is connected to a drain tube placed inside the patient's thoracic cavity, abdominal cavity, or the like. Each drain tube is included in a suction path, and the distal end of each drain tube is desirably placed at a different location inside the thoracic cavity, abdominal cavity, or the like. However, at least two distal ends of multiple drain tubes may be placed adjacent to each other so as to aspirate body fluids such as blood from the same location inside the thoracic cavity, abdominal cavity, or the like. The first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 are configured to be detachable from the suction system 200. However, the suction system 200 may include the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213. In this case, the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 may be configured integrally with part of the suction system 200.

[0045] The suction system 200 aspirates bodily fluids (hereinafter also referred to as "drainage fluids"), which are an example of liquids, from the thoracic cavity, abdominal cavity, and other parts of the patient's body. The first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 each have an internal flow path through which the drainage fluid flows. The suction tube 216 also has a flow path through which air flows so that suction pressure corresponding to the negative pressure generated by the suction device 215 is applied to the suction path. For example, when aspirating unnecessary drainage fluids from the abdominal cavity or thoracic cavity after a surgical procedure, a suction pressure not exceeding a maximum negative pressure of -5 kP is applied. However, for the purpose of treatment, the suction pressure may exceed a negative pressure of -5 kP. For example, when performing negative pressure wound therapy on a chronic wound, the suction pressure may be within a range of -16.7 kP to -20.0 kP. When aspirating drainage fluids from the abdominal cavity or thoracic cavity, it may be necessary to control the appropriate amount of suction at each suction point. In this case, different suction pressures may be applied to each suction path. As an example, the suction pressure may be set in the suction device 215 as needed so that the suction pressure when the first suction path is open differs from the suction pressure when the second or third suction path is open. The drained liquid sucked by the suction system 200 flows through the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213. The number of the multiple suction paths is not limited to three and may be four or more. In this case, the number of suction devices 215 is less than the number of the multiple suction paths. That is, it is sufficient that at least one suction device 215 is connected to two or more suction paths. Therefore, the suction system 200 may include two or more suction devices 215.

[0046] The suction system 200 also includes a first solenoid mechanism 220A, a second solenoid mechanism 220B, and a third solenoid mechanism 220C as examples of closing units that close each of the multiple suction paths. Hereinafter, the first solenoid mechanism 220A, the second solenoid mechanism 220B, and the third solenoid mechanism 220C may be collectively referred to simply as the solenoid mechanism 220. Each of the solenoid mechanisms 220 has a well-known structure, and as an example, has a mechanism in which a movable pin moves within a coil. Each of the solenoid mechanisms 220 compresses a portion of the suction tube 216 to close it. Note that a suction tube that is not closed by the solenoid mechanism 220 may be connected to the suction system 200.

[0047] When no voltage is applied to the solenoid mechanism 220, the suction tubes 216 are compressed by the pins. This compresses the internal flow paths and closes each of the suction tubes 216. As a result, air flow is obstructed in the compressed suction tubes 216, and suction stops. Alternatively, the solenoid mechanism 220 may move a blocking member that closes the internal flow path of the suction tube 216 back and forth. In this case, the solenoid mechanism 220 moves the blocking member between a blocking position where it protrudes into the internal flow path of the suction tube 216 and an open position where it retracts from the internal flow path. The blocking member in the blocking position closes the internal flow path of the suction tube 216 and obstructs the flow of air through the suction tube 216.

[0048] Furthermore, the suction system 200 includes a suction device 215 as an example of a suction unit that generates suction pressure acting on multiple suction paths. Examples of the suction device 215 include a negative pressure pump, wall suction, or a drainage bag. For example, the wall suction is a negative pressure source provided on the wall of an operating room or a hospital room. The drainage bag is a bag with a spring disposed inside, which expands due to the force of the spring expanding, generating negative pressure.

[0049] 5, the drainage tank 217 is disposed between the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 and the suction tube 216. The first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 are connected to each drainage tank 217. That is, the suction device 215 is connected to the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 via the suction tube 216 and the drainage tank 217. The drainage sucked through the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 is collected in the drainage tank 217.

[0050] The drainage tank 217 has a suction volume unit 214 that indicates the amount of suctioned liquid, either the amount of suctioned liquid suctioned through each suction path or the total amount of suctioned liquid suctioned through all suction paths. For example, the suction volume unit 214 indicates the approximate volume or weight of the drainage liquid, allowing the user to know the amount of liquid suctioned through the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213. The suction volume unit 214 may also indicate the amount of suctioned liquid per predetermined time period, for example, per hour, per 12 hours, or per day. For example, the suction volume unit 214 is a display device included in the suction system 200, such as a touch panel display, a liquid crystal display, or an organic electroluminescence display. The suction volume unit 214 may also be connected to the control unit 219. In this case, the control unit 219 receives data indicating the amount of liquid from a liquid volume detection unit (not shown) provided in the drainage tank 217 and displays the data on the suction volume unit 214. As an example, the liquid level detection unit is a weighing scale that measures the weight of the liquid in the drainage tank 217. Alternatively, the liquid level detection unit may be a sensor that detects the volume of the liquid in the drainage tank 217. For example, the sensor detects the position of the liquid level of the accumulated drainage liquid, thereby detecting the volume corresponding to the position of the liquid level.

[0051] Alternatively, the suction volume unit 214 may be a scale indicating the amount of liquid. For example, at least a portion of the drainage tank 217 is transparent, and the user can visually check the position of the liquid level from outside the drainage tank 217. The user can then compare the position of the liquid level with the scale provided on the drainage tank 217 to recognize the total amount of drainage liquid that has been suctioned. In other words, the scale serving as the suction volume unit 214 functions to indicate to the user the total amount of drainage liquid that has been suctioned by comparing it with the liquid level.

[0052] [Suction Order] During surgical treatment of an affected area in the thoracic or abdominal cavity, when the thoracic or abdominal cavity is closed after treatment of the affected area, blood or other substances may continue to leak from the treated area even after the thoracic or abdominal closure. In this case, a drain tube connected to a drainage tube connected to a continuous low negative pressure suction system, which is an example of the suction system 200, is placed inside the thoracic or abdominal cavity. This allows drainage fluid to be removed from the patient's body after the thoracic or abdominal closure. In some cases, multiple affected areas may be treated, and multiple drain tubes are placed depending on the patient's symptoms. For example, in severe cases, three or more drain tubes may be placed.

[0053] When multiple drain tubes are used, the tip of each drain tube is placed at each of multiple locations in the patient's body where drainage fluid is likely to accumulate. A suction device 215 can be connected to each drainage tube. However, connecting each drainage tube to multiple suction devices 215 would require multiple suction devices 215, which would increase the size and cost of the suction system 200. Therefore, the multiple suction paths are sequentially opened using fewer suction devices 215. This prevents the suction system 200 from becoming larger in size and becoming more expensive.

[0054] Specifically, any one of the multiple suction paths connected to one suction device 215 is opened to communicate with the suction device 215. Then, all other suction paths are closed to prevent communication with the suction device 215. After a predetermined time has elapsed, any one of the closed suction paths is opened to connect to the suction device 215. Then, all other suction paths are closed to prevent communication with the suction device 215. After a predetermined time has elapsed, any one of the closed suction paths excluding the suction path that was opened earlier is opened to connect to the suction device 215. Then, all other suction paths are closed to prevent communication with the suction device 215. Similarly, the suction path to be opened is sequentially changed, and waste liquid is aspirated from any one of the multiple suction paths.

[0055] 5, the suction system 200 includes a control unit 219 that controls the solenoid mechanism 220. As an example, the control unit 219 is a computer having a processor (not shown) and a memory serving as a computer-readable non-transitory storage medium storing a control program. Based on the program stored in the memory, the processor controls the entire suction system 200, including the solenoid mechanism 220 and the suction device 215, and also comprehensively controls various processes. The control unit 219 may be realized by a hardware circuit, or may be realized as a logic device that combines computer hardware and software.

[0056] The control unit 219 controls the solenoid mechanism 220 to open the first suction tube 216A of the first suction path as one of the plurality of suction paths, and close the second suction tube 216B and the third suction tube 216C of the first and second suction paths as the remaining suction paths. Thereafter, the control unit 219 controls the solenoid mechanism 220 to open the second suction tube 216B of the second suction path as another suction path different from the previously opened first suction path among the remaining suction paths, and close the first suction tube 216A and the third suction tube 216C of the first and third suction paths as other suction paths including the previously opened first suction path.

[0057] For example, the first solenoid mechanism 220A first opens the first suction tube 216A of the suction tubes 216, and closes the remaining suction tubes, the second suction tube 216B and the third suction tube 216C. As a result, the second suction tube 216B and the third suction tube 216C are compressed by the second solenoid mechanism 220B and the third solenoid mechanism 220C, and the suction of drained liquid through the first drainage tube 211 and the third drainage tube 213 is stopped. On the other hand, the internal flow path of the first suction tube 216A is not compressed. Therefore, the flow of air is not obstructed, and drained liquid is suctioned through the first drainage tube 211. Note that the start of opening and the start of closing do not have to be simultaneous, and there may be a time lag between them.

[0058] After a predetermined time has elapsed since the first suction tube 216A was opened, the second solenoid mechanism 220B opens the second suction tube 216B as a suction tube different from the previously opened first suction tube 216A. Here, the remaining suction tubes are the second suction tube 216B and the third suction tube 216C. Therefore, the suction tube different from the previously opened first suction tube 216A is either the second suction tube 216B or the third suction tube 216C. Additionally, the first solenoid mechanism 220A and the third solenoid mechanism 220C close the first suction tube 216A and the third suction tube 216C as the other suction tubes, including the previously opened first suction tube 216A. As a result, the first suction tube 216A and the third suction tube 216C are compressed by the first solenoid mechanism 220A and the third solenoid mechanism 220C, and the suction of drained liquid through the first drainage tube 211 and the third drainage tube 213 is stopped. On the other hand, the internal flow path of the second suction tube 216B is not crushed. Therefore, the flow of air is not obstructed, and drained liquid is suctioned through the second drainage tube 212. Note that the end of opening and the end of closing do not have to be simultaneous, and there may be a time lag between them.

[0059] When the second suction tube 216B is opened, the remaining suction tubes are the first suction tube 216A and the third suction tube 216C. Among the remaining suction tubes, the first suction tube 216A is included in the first suction path, which is the path that was opened first. In this case, the control unit 219 controls the solenoid mechanism 220 to open the third suction tube 216C as another suction tube from among the remaining suction tubes excluding the first suction tube 216A. In addition, the first solenoid mechanism 220A and the second solenoid mechanism 220B close the first suction tube 216A and the second suction tube 216B as the other suction tubes. As a result, the first solenoid mechanism 220A and the second solenoid mechanism 220B compress the first suction tube 216A and the second suction tube 216B, and the suction of drainage liquid through the first drainage tube 211 and the second drainage tube 212 is stopped. On the other hand, the internal flow path of the third suction tube 216C is not crushed, so the air flow is not obstructed and the drainage liquid can be sucked through the third drainage tube 213.

[0060] This opens all of the suction tubes 216. Therefore, the control unit 219 controls the solenoid mechanism 220 to reopen the first suction tube 216A that was opened initially, and close the second suction tube 216B and the third suction tube 216C. Thereafter, opening and closing are performed sequentially in the same manner.

[0061] The operation of the solenoid mechanism 220 will be described in detail with reference to Figure 6. The solenoid mechanism 220 opens the suction tube 216 when it is in the ON state and closes the suction tube 216 when it is in the OFF state. At timing t0 immediately after the start of suction, the first solenoid mechanism 220A is in the ON state, and the first suction tube 216A is opened. At this time, the second solenoid mechanism 220B and the third solenoid mechanism 220C are in the OFF state, and the second suction tube 216B and the third suction tube 216C are closed. Therefore, the drainage tank 217 to which the first drainage tube 211 is connected is in communication with the suction device 215, and only the first drainage tube 211 is in the suction state between timings t0 and t1.

[0062] At time t1, a predetermined time after time t0, second solenoid mechanism 220B is turned on, and second suction tube 216B is opened. At this time, first solenoid mechanism 220A and third solenoid mechanism 220C are turned off, and first suction tube 216A and third suction tube 216C are closed. Therefore, drainage tank 217, to which second drainage tube 212 is connected, communicates with suction device 215, and only second drainage tube 212 is in the suction state between times t1 and t2.

[0063] At time t2, a predetermined time after time t1, third solenoid mechanism 220C is turned on, and third suction tube 216C is opened. At this time, first solenoid mechanism 220A and second solenoid mechanism 220B are turned off, and first suction tube 216A and second suction tube 216B are closed. Therefore, drainage tank 217, to which third drainage tube 213 is connected, communicates with suction device 215, and only third drainage tube 213 is in a suction state from time t2 to time t3. After that, when a predetermined time has elapsed from time t2, first solenoid mechanism 220A is turned on. Thereafter, similar opening and closing are repeated until suction is completed.

[0064] The control unit 219 controls the solenoid mechanism 220 to open the multiple suction paths in order. For example, the predetermined order for opening the multiple suction paths is set so that if there is a previously opened path among the remaining suction paths, one of the remaining suction paths excluding the previously opened path is opened. Furthermore, the predetermined order is set so that after all of the multiple suction paths have been opened, the first opened suction path is opened again.

[0065] 5 as an example, when the first suction tube 216A of the suction tubes 216 is opened, the remaining suction tubes are the second suction tube 216B and the third suction tube 216C. Therefore, either the second suction tube 216B or the third suction tube 216C is opened as the next suction tube to be opened after the first suction tube 216A. Furthermore, when the second suction tube 216B is opened next, the next suction tube to be opened is the remaining suction tubes, the first suction tube 216A and the third suction tube 216C, excluding the first suction tube 216A that was opened earlier. Therefore, the third suction tube 216C is opened as the next suction tube. As a result, all of the multiple suction tubes are opened, and the first suction tube 216A that was opened first is then opened again.

[0066] According to the suction system 200 of the second embodiment described above, when multiple suction paths are used, liquid can be aspirated using fewer suction sources. Furthermore, even when multiple suction paths are connected to a single suction source, liquid can be aspirated efficiently. That is, the tip ends of the multiple suction paths can be positioned at multiple locations where drained liquid is likely to accumulate. Furthermore, the amount of drained liquid aspirated from the abdominal or thoracic cavity does not exceed the amount of body fluid leaking therein. Therefore, if a large amount of leaking body fluid is confirmed based on the amount of drained liquid aspirated, a doctor can provide treatment or measures as necessary.

[0067] The solenoid mechanism 220 that is next to be turned on may change from the off state to the on state slightly earlier than the timing at which the previously turned on solenoid mechanism 220 changes to the off state. In other words, a state in which two solenoid mechanisms 220 are simultaneously in the on state may occur for a short period of time. This is because a short period of time has almost no effect on suction. Also, a state in which all solenoid mechanisms 220 are in the off state may occur for a short period of time.

[0068] [Third embodiment] A suction system 300 according to a third embodiment will be described with reference to Figs. 7 to 11. The third embodiment differs from the first embodiment in that it includes multiple cams. Fig. 7 is a schematic diagram showing the suction system 300 with the first drainage tube 311 open. Fig. 8 is a schematic diagram showing the suction system 300 with the second drainage tube 312 closed. Fig. 9 is a schematic diagram showing the suction system 300 with the third drainage tube 313 closed. In the states shown in Figs. 7 to 9, the second drainage tube 312 and the third drainage tube 313 are closed, and saliva is suctioned via the first drainage tube 311.

[0069] FIG. 10 is an explanatory diagram illustrating the change in the rotation angle of first cam 321A over time, with the vertical axis representing the rotation angle from the start of rotation of first cam 321A and the horizontal axis representing the time elapsed since the start of rotation of first cam 321A. FIG. 11 is a schematic cross-sectional view of first cam 321A, second cam 321B, and third cam 321C. FIG. 11 shows a cross section passing through rotation center CP indicated by a dashed dotted line and perpendicular to the cam 321-side surface of compression unit 323, as viewed from a horizontal direction perpendicular to rotation center CP. In the following description, first cam 321A, second cam 321B, and third cam 321C may be collectively referred to simply as cam 321.

[0070] 7, the suction system 300 includes, as an example of a plurality of suction paths, a first suction path including a first drainage tube 311 and a suction tube 16, a second suction path including a second drainage tube 312 and a suction tube 16, and a third suction path including a third drainage tube 313 and a suction tube 16. The first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 are arranged in overlapping positions facing the compression unit 323. In the following description, the first suction path, the second suction path, and the third suction path may be collectively referred to simply as the suction paths.

[0071] The first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 have internal flow paths through which saliva flows. The suction tube 16 also has a flow path through which air flows so that suction pressure corresponding to the negative pressure generated by the pump 15 acts on the suction path, and suction pressure corresponding to the flow rate of the flowing air acts on the suction path. The first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 are connected to the suction system 300. The distal ends of the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 are placed in the patient's oral cavity. Saliva sucked by the suction system 300 flows through the internal flow paths of the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313.

[0072] The suction system 300 also includes a cam mechanism 320 as an example of a closing unit that closes each of the multiple suction paths. The cam mechanism 320 includes a first cam 321A, a second cam 321B, and a third cam 321C, which are examples of rotating bodies. Each cam 321 has the same shape and rotates in the same direction around a rotation center CP. For example, each cam 321 has a shape consisting of a circle centered on the rotation center CP, with a sector-shaped arc portion with a central angle of 120° removed. Using the rotation center CP as a reference, the second cam 321B is tilted 120° relative to the first cam 321A, and the third cam 321C is tilted 240° relative to the first cam 321A. At least two of the first cam 321A, the second cam 321B, and the third cam 321C may have different shapes. Furthermore, the inclination of second cam 321B and third cam 321C relative to first cam 321A may be different from each other. By varying the shape or posture of the cams, the length of time that each suction path is open can be made different.

[0073] However, for ease of explanation, the example in FIG. 7 only illustrates first cam 321A when the rotation angle is 0°. In reality, second cam 321B ( FIG. 8 ) and third cam 321C ( FIG. 9 ) are disposed at positions overlapping first cam 321A in the extension direction of rotation center CP. Cam mechanism 320 also includes motor 22 for rotating each cam 321. When cam 321 is rotated by motor 22, each of first drainage tube 311, second drainage tube 312, and third drainage tube 313 in contact with cam 321 is sandwiched and compressed between cam 321 and compression unit 323. This compresses the internal flow path, closing each of first drainage tube 311, second drainage tube 312, and third drainage tube 313. Therefore, the flow of saliva is hindered in the compressed drainage tubes, and suction stops. 7, the internal flow path of first drainage tube 311 that is not compressed by first cam 321A is not crushed, so the flow of saliva is not obstructed and saliva is sucked through first drainage tube 311 in the direction indicated by arrow DA.

[0074] Furthermore, the suction path is provided with a saliva tank 17, which serves as an example of a liquid tank and stores saliva. In the examples of FIGS. 7 to 9, the saliva tank 17 is disposed between the suction tube 16 and the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313. The first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 are connected to the saliva tank 17. Saliva sucked through the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 is stored in the saliva tank 17. The first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 are connected to the saliva tank 17 via a connecting tube that branches into three. However, the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313 may each be connected to the saliva tank 17 individually.

[0075] [Suction Order] The suction sequence will be described with reference to FIGS. 7 to 9. The suction system 300 includes a control unit 19 that controls a cam mechanism 320. The control unit 19 controls the cam mechanism 320 to open one of the first suction path including the first drainage tube 311, the second suction path including the second drainage tube 312, and the third suction path including the third drainage tube 313, and close the remaining suction paths among the first suction path, the second suction path, and the third suction path. For example, the control unit 19 controls the rotation speed of the cam 321 of the cam mechanism 320. Thereafter, the control unit 19 controls the cam mechanism 320 to open another suction path that is different from the previously opened one of the remaining suction paths, and close the other suction paths among the first suction path, the second suction path, and the third suction path, including the previously opened one.

[0076] For example, as shown in Fig. 7, the cam mechanism 320 first opens the first drainage tube 311. At this time, the first cam 321A, whose rotation angle is 0°, does not press on the first drainage tube 311. Therefore, the first suction path including the first drainage tube 311 is open. The flow of saliva is not obstructed, and saliva is suctioned via the first drainage tube 311 in the direction indicated by the arrow DA. At this time, the cam mechanism 320 closes the second drainage tube 312 and the third drainage tube 313 of the remaining second and third suction paths, as shown in Figs. 8 and 9.

[0077] That is, as shown in FIG. 8, second cam 321B, which is inclined by 120° with respect to first cam 321A, presses second drainage tube 312. Therefore, the second suction path including second drainage tube 312 is closed. Suction of saliva via second drainage tube 312 is stopped. Similarly, third cam 321C, which is inclined by 240° with respect to first cam 321A, presses third drainage tube 313 as shown in FIG. 9. Therefore, the third suction path including third drainage tube 313 is closed. Suction of saliva via third drainage tube 313 is stopped. For ease of explanation, only second cam 321B is illustrated in the example of FIG. 8, and only third cam 321C is illustrated in the example of FIG. 9. However, in reality, second cam 321B and third cam 321C are arranged at positions overlapping with first cam 321A in the extension direction of rotation center CP.

[0078] The cam mechanism 320 then sequentially opens one suction path from among the multiple suction paths and closes the remaining paths. That is, as each cam 321 rotates, the cam mechanism 320 opens the third suction path as a separate suction path different from the previously opened first suction path. That is, the cam mechanism 320 opens the third drainage tube 313 of the third suction path. In addition, the cam mechanism 320 closes the first suction path and the second suction path as other suction paths, including the previously opened first suction path. Then, as each cam 321 rotates further, the cam mechanism 320 opens the second suction path as another suction path. That is, the cam mechanism 320 opens the second drainage tube 312 of the second suction path. In addition, the cam mechanism 320 closes the first suction path and the third suction path as other suction paths.

[0079] Referring to FIG. 10, the operation of the first cam 321A, which rotates once every 60 seconds, will be described in detail. First, when the elapsed time at the start of rotation is 0 seconds, the rotation angle of the first cam 321A is 0°. At this time, the first drainage tube 311 is open, and the second drainage tube 312 and the third drainage tube 313 are closed. That is, as shown in FIG. 11A, the first cam 321A is separated from the first drainage tube 311, and the first drainage tube 311 is open. Meanwhile, the second cam 321B presses the second drainage tube 312, and the third cam 321C presses the third drainage tube 313. Therefore, the second drainage tube 312 and the third drainage tube 313 are closed.

[0080] Then, when 10 seconds have passed and the rotation angle of first cam 321A is 60°, first drainage tube 311 and second drainage tube 312 are closed, and third drainage tube 313 is open. That is, as shown in FIG. 11B , third cam 321C is separated from third drainage tube 313, and third drainage tube 313 is open. Meanwhile, first cam 321A is pressing against first drainage tube 311, and second cam 321B is pressing against second drainage tube 312. Therefore, first drainage tube 311 and second drainage tube 312 are closed. are.

[0081] When 30 seconds have passed and the rotation angle of first cam 321A is 180°, first drainage tube 311 and third drainage tube 313 are closed, and second drainage tube 312 is open. That is, as shown in Fig. 11C, second cam 321B is separated from second drainage tube 312, and second drainage tube 312 is open. Meanwhile, first cam 321A is pressing against first drainage tube 311, and third cam 321C is pressing against third drainage tube 313. Therefore, first drainage tube 311 and third drainage tube 313 are closed.

[0082] When 50 seconds have passed and the rotation angle of first cam 321A is 60°, first drainage tube 311 is again opened, and second drainage tube 312 and third drainage tube 313 are closed. That is, first drainage tube 311 is opened, while second drainage tube 312 and third drainage tube 313 are closed. Thereafter, the same opening and closing is repeated until the suction is completed.

[0083] The suction system 300 of the third embodiment described above also allows for the use of fewer suction sources to aspirate liquid when multiple suction paths are used. Furthermore, even when multiple suction paths are connected to a single suction source, liquid can be efficiently aspirated. That is, the tip ends of the multiple drainage tubes can be positioned at multiple locations where saliva tends to accumulate. Furthermore, because saliva can be aspirated intermittently and reliably from each drainage tube, the frequency of periodic checks of saliva accumulation can be reduced.

[0084] Instead of the three cams 321, a single cam having recesses at positions corresponding to the respective drainage tubes may be used. For example, the cam may be configured so that its thickness (i.e., its height in the direction of extension of the rotation center CP) is equal to the total height of the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313. As an example, the cam has a generally cylindrical shape formed by bonding together the first cam 321A, the second cam 321B, and the third cam 321C. In this case, the recess faces the drainage tube to be opened among the first drainage tube 311, the second drainage tube 312, and the third drainage tube 313. Therefore, the drainage tube facing the recess is opened. Meanwhile, the remaining drainage tubes are compressed by the cam and closed. Then, as the cam rotates, a recess formed at a different position faces the next drainage tube to be opened. As the cam rotates further, a recess formed at a different position faces the next drainage tube to be opened. Even with a cam having such a shape, it is possible to open a plurality of suction paths in sequence.

[0085] Although the present invention has been described above with reference to each embodiment, the present invention is not limited to the above-described embodiments. The present invention also includes inventions that have been modified without departing from the scope of the present invention, and inventions equivalent to the present invention. Furthermore, each embodiment and each modified form can be combined as appropriate without departing from the scope of the present invention.

[0086] For example, the distal end of each drain tube may be positioned inside another part of the patient's body (e.g., the trachea). Furthermore, the controller 19, 219 may open one suction path after a predetermined amount of liquid has accumulated in the liquid reservoir corresponding to that suction path, and then open another suction path. Furthermore, the saliva reservoir 17 of the suction system 100 or 300 may include a suction volume controller 214.

[0087] Furthermore, the suction system 200 may include the cam mechanism 20 or the cam mechanism 320. In this case, the control unit 219 synchronizes the opening and closing of the first drainage tube 211, the second drainage tube 212, and the third drainage tube 213 by the cam mechanism 20 or the cam mechanism 320 with the opening and closing of the first suction tube 216A, the second suction tube 216B, and the third suction tube 216C by the solenoid mechanism 220. [Explanation of symbols]

[0088] 11: First drainage tube (first suction path) 12: Second drainage tube (second suction path) 15: Pump (suction part) 16: Suction tube (suction path) 17: Salivary tank (liquid tank) 19: Control section 20: Cam mechanism (closing part) 21: Cam 22: Motor 100: Suction system 200: Suction system 211: First drainage tube (first suction path) 212: Second drainage tube (second suction path) 213: Third drainage tube (third suction path) 214: Suction amount section 215: Suction device (suction part) 216A: First suction tube (first suction path) 216B: Second suction tube (second suction path) 216C: Third suction tube (third suction path) 217: Drainage tank (liquid tank) 219: Control unit 220: Solenoid mechanism 300: Suction system 311: First drainage tube (first suction path) 312: Second drainage tube (second suction path) 313: Third drainage tube (third suction path) 320: Cam mechanism (closing part) 321A: First Cam (Cam) 321B: Second Cam (Cam) 321C: Third Cam (Cam)

Claims

1. 1. A suction system that applies suction pressure to a plurality of suction paths including a tube that suctions liquid from a distal end portion disposed inside a patient's body, the suction pressure aspirating the liquid, a closing portion that closes each of the plurality of suction paths; a control unit that controls the closing unit to open one of the plurality of suction paths and close the remaining suction paths of the plurality of suction paths, and then open another of the remaining suction paths that is different from the one suction path and close the other suction paths of the plurality of suction paths including the one suction path.

2. The suction system according to claim 1 , wherein the control unit controls the closing unit to open the other suction path after a predetermined time has elapsed since the opening of the one suction path.

3. A suction system that applies suction pressure to multiple suction paths to draw liquid from a patient, a closing portion that closes each of the plurality of suction paths; a control unit that controls the closing unit to open one of the plurality of suction paths and close the remaining suction paths of the plurality of suction paths, and then open another suction path of the remaining suction paths that is different from the one suction path and close the other suction paths of the plurality of suction paths including the one suction path, The control unit controls the closing unit to open another suction path from among the remaining suction paths excluding the first-opening path if there is a first-opening path among the remaining suction paths, and to open the one suction path again after all of the multiple suction paths have been opened.

4. A suction system that applies suction pressure to multiple suction paths to draw fluid from a patient, comprising: a closing portion that closes each of the plurality of suction paths; a control unit that controls the closing unit to open one of the plurality of suction paths and close the remaining suction paths of the plurality of suction paths, and then open another of the remaining suction paths that is different from the one suction path and close the other suction paths including the one suction path of the plurality of suction paths; a suction unit that generates the suction pressure to be applied to the plurality of suction paths, A suction system, wherein the suction path is provided with a liquid tank for storing the liquid.

5. The suction system according to claim 4 , wherein the liquid tank has a suction volume portion that indicates the volume of the liquid that has been suctioned.

6. The suction system according to claim 1 , wherein the closing section has a solenoid mechanism that closes the internal flow path of each of the plurality of suction paths.

7. The suction system according to claim 1 , wherein the closing section includes a cam that compresses and closes a portion of each of the plurality of suction paths, and a motor that rotates the cam.

8. A method for controlling an aspiration system including a closing unit that applies a suction pressure to a plurality of aspiration paths, each of which includes a tube that aspirates a liquid from a distal end portion disposed inside a patient's body, to aspirate the liquid, and a computer, the method comprising: A method for controlling a suction system, in which the computer controls the closing unit to open one of the plurality of suction paths and close the remaining suction paths of the plurality of suction paths, and then open another of the remaining suction paths that is different from the one suction path and close the other suction paths of the plurality of suction paths including the one suction path.

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