Abstract:
According to the present invention, a problem of closed systems, namely minimizing the number of electromagnetic valves required to control a plurality of flow paths, can be addressed, and thus a low-cost cell culture device can be achieved. In this flow-path control method for X number of flow paths satisfying X≦2 N , the X number of flow paths are selected by using N number of valves to simultaneously and selectively control the opening and closing of the plurality of flow paths.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a valve for flow-path control in a device including a plurality of flow paths such as a cell culture device or an automatic analysis device. 
       BACKGROUND ART 
       [0002]    There is a valve called multiple switching valve for dispensing a plurality of reagents with one cylinder. An example of an automatic analysis device including the valve is described in JP-A-60-93356. 
         [0003]    There is a valve called pinch valve for crushing (pinching) a flow path having elasticity from the outer side and controlling fluid. Examples of a cell culture device and an automatic analysis device including the valve are respectively described in JP-A-2011-142837 and JP-A-1-12265. 
       CITATION LIST 
     Patent Literature 
       [0004]    Patent Literature 1: JP-A-60-93356 
         [0005]    Patent Literature 2: JP-A-2011-142837 
         [0006]    Patent Literature 3: JP-A-1-12265 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0007]    The pinch valve can control opening and closing of a flow path without directly touching fluid flowing on the inner side of the flow path. Therefore, it is unlikely that the fluid is contaminated. The valve itself is not soiled. Therefore, the pinch valve is appreciated in devices in which contamination is concerned such as a cell culture device and an automatic analysis device. In particular, in the cell culture device, basically, a flow path contaminated by a flow of a culture medium or the like is discarded. The pinch valve not soiled in itself can be economically recycled. 
         [0008]    When there are a plurality of flow paths and it is attempted to selectively control opening and closing, if pinch valves are provided in the respective flow paths, at least the control is possible. However, if the number of flow paths increases, the number of pinch valves also increases. This leads to an increase in costs and the device is increased in size. 
         [0009]    For the control of the plurality of flow paths, it is also conceivable to use the multiple switching valve described in Patent Literature 1. However, since the inside of the valve is in contact with liquid, use of the multiple switching valve is undesirable from the viewpoint of contamination. 
         [0010]    There is a demand for a valve that has less risk of contamination and is small in size and inexpensive. 
       Solution to Problem 
       [0011]    In order to solve the problems, for example, a configuration described in claims is adopted. 
         [0012]    This application is a flow-path control method for X number of flow paths satisfying X≦2 N . The X number of flow paths are selected by selectively simultaneously controlling opening and closing of the plurality of flow paths using N number of valves. 
       Advantageous Effect of Invention 
       [0013]    According to the present invention, it is possible to eliminate a risk of contamination and minimize the number of pinch valves required for control of a plurality of flow paths. Therefore, it is possible to reduce the size and the costs of a device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a schematic explanatory diagram of a flow-path control method of the present invention. 
           [0015]      FIG. 2  is a diagram showing the structure of a universal-type pinch valve. 
           [0016]      FIG. 3  is a diagram showing a method of inserting eight tubes through pinch valves in three places. 
           [0017]      FIG. 4  is a diagram showing a pinch-valve control method for tube selection. 
           [0018]      FIG. 5  is a diagram showing an example in which tubes to be on an NC side and tubes to be on an NO side in the pinch valves are sorted and collected and can be collectively set. 
           [0019]      FIG. 6  is a diagram showing another example of a tube holder. 
           [0020]      FIG. 7  is a diagram showing an example of the structures of a pinch member and a supporting member. 
           [0021]      FIG. 8  is a diagram showing a closed culture system. 
           [0022]      FIG. 9  is a diagram showing closed culture systems including a flow-path selecting mechanism. 
           [0023]      FIG. 10  is a diagram showing a reagent dispensing system of an automatic analysis device. 
           [0024]      FIG. 11  is a diagram showing a reagent dispensing system including a flow-path selecting mechanism. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0025]    Embodiments are explained below with reference to the drawings. 
         [0026]      FIG. 1  is an example in which eight tubes  1  are controlled by three universal-type pinch valves  2 . The universal-type pinch valve is capable of performing two kinds of control of normal open and normal close with control of one actuator and has structure shown in  FIG. 2 . In the following explanation, when “pinch valve” is used without notice, the pinch valve indicates the universal-type pinch valve. 
         [0027]    A pinch member  3  is fixed to a movable core  4  and moves according to a movement of the movable core  4 . The pinch member  3  and the movable core  4  are collectively referred to as actuator as well. A supporting member  5  is fixed to a case  6 . These members do not move. The supporting member  5  is configured from an NC (Normal Close)-side member  5   a  and an NO (Normal Open)-side member  5   b.  Tubes desired to be controlled are inserted between the supporting member  5  and the pinch member  3 . 
         [0028]    The actuator moves up and down in this figure with force by a spring  7  and magnetic force generated by a coil  8 . When the coil  8  is not energized, the actuator is pushed up by the force of the spring  7  and the tube set on the NC side is crushed (pinched). When the coil  8  is energized, the actuator is attracted to a fixed core  9  side and the tube on the NO side is crushed. At this point, the tube on the NC side is restored by elasticity. Note that, as a driving source of the actuator, besides electromagnetism shown in the figure, pressure (air pressure or liquid pressure) or mechanical force of a cam or the like may be used. 
         [0029]    The pinch member  3  and the supporting member  5  have shapes that enable a plurality of tubes to be simultaneously set respectively on the NC side and the NO side. It is possible to simultaneously control the set tubes. 
         [0030]    A method of inserting eight tubs through pinch valves in three places is shown in  FIG. 3 . Eight tubes i to viii are inserted through pinch valves A, B, and C in three places in a state of (a). NC/NO states of the pinch valves are summarized for each of the tubes as shown in (b). 
         [0031]      FIG. 4  shows a pinch-valve control method for tube selection. When the pinch valves in the three places are controlled in combinations of ON/OFF with respect to the tubes to be selected, the tubes can be brought into the open state. 
         [0032]    (b) shows details of the control. (i) is a state in which all the pinch valves are OFF. At this point, the tube i is in the open state. When the pinch valve A is switched to ON, a state is as shown in (ii) . The tube i is closed and the tube ii is brought into the open state. Similarly, any one of the eight tubes can be opened by controlling the pinch valves in the three places. 
         [0033]    Eight kinds of control can be performed by the combinations of the three pinch valves. However, numbers of tubes may be used as explained below. For example, when it is attempted to select and control seven tubes, which is less than the eight tubes by one, with the three pinch valves, the respective tubes can be controlled. Even if the absent one tube is selected, the opening and closing of the remaining seven tubes are not affected. The number of tubes only has to be smaller than the number of combinations of the kinds of control of the pinch valves. 2 N  kinds of control are possible with respect to the number N of the pinch valves. Therefore, N number of pinch valves only have to be present for selection of X number of flow paths satisfying X≦2 N . 
         [0034]    If one tube is unused intentionally and is not used in the combinations in which the tube passes the NO side in all the pinch valves, when a power supply is turned off, a state can be obtained in which all the tubes are necessarily closed. It is possible to prevent the tubes from changing to the open state unexpectedly because of a power failure or the like. This serves as failsafe as well. 
         [0035]    Note that, instead of the universal type, when an NC-type or NO-type pinch valve that switches one of open or close with one actuator is used, a function same as the function of the universal type can be realized by two combinations. Therefore, when 2N number of NC-type or NO-type pinch valves are prepared for selection of X number of flow paths satisfying X≦2 N , the flow path selection explained above is also possible. 
       First Embodiment 
       [0036]    In an embodiment explained below, a method of setting tubes in pinch valves is explained. 
         [0037]    In the flow-path (tube) selecting method of the present invention, a method of inserting a plurality of tubes through pinch valves is important. However, on the other hand, the method is complicated. Therefore, if it is attempted to set the tubes one by one, it takes time. Likelihood of erroneous insertion cannot be eliminated. Therefore, it is desirable that tubes to be on an NC side and tubes to be on an NO side in the pinch valves are sorted and collected in advance and can be collectively set. 
         [0038]    An example of the setting is shown in  FIG. 5 . A tube holder  10  includes two tube holding sections  10   a  and  10   b,  which respectively hold the tubes for NC and for NO. The tube holder  10  includes a fitting section  10   c  such that the tube holder  10  can be slid and fit in the supporting member  5  of the pinch valve. The tubes  1  are sorted for NC and for NO and inserted through the tube holder  10  in advance. By fitting the tube holder  10  in the supporting member  5  of the pinch valve, the tubes  1  are set in the pinch valve. A tube set may be prepared in which 2 N  number of tubes  1  are inserted through N number of tube holders  10  in a correct combination in advance. A user is released from a trouble of inserting the tubes. 
         [0039]    To prevent the NC side and the NO side from being mistaken when the tube holder is fit in the supporting member, there may be an idea for forming the shape of the fitting section asymmetrical to provide a mechanism for wrong fitting prevention. When there are a plurality of tube holders and a plurality of pinch valves, there may be an idea for coloring supporting members for the tube holders and the pinch valves forming pairs to distinguish the supporting members. 
         [0040]    Since it is important to sort the tubes in advance, the tubes may be divided into the NC side and the NO side and the tubes on the NC side and the tubes on the NO side may be respectively bound by a tape or an adhesive rather than being held by the tube holder  10 . 
         [0041]    The NC side of the pinch valve is narrow and it is hard to insert the tubes through the NC side. Therefore, the tubes may be inserted through the NO side and the NC side in order while switching the position of the pinch member  3 . The tube holder  11  shown in  FIG. 6  includes two tube holding sections  11   a  and  11   b  and a flexible portion  11   c.  It is desirable to insert the tube on the NO side first, subsequently drive the actuator to open the NC side, and insert the tube on the NC side. There may be an idea for preventing erroneous insertion on the NC side and the NO side. For example, the tubes may have a shape for disabling the erroneous insertion or there may be an idea for coloring the tubes to make the erroneous insertion less easily occur. 
         [0042]    The pinch member and the supporting member may be detachable from the pinch valve. A tube set may be prepared in a state in which the pinch member and the supporting member are incorporated in the tubes. As shown in  FIG. 7( a ) , a pinch valve  12  can be disassembled into a main body  12   a,  a pinch member  12   b,  and a supporting member  12   c.  The supporting member  12   c  can be further disassembled into  12   c   1  and  12   c   2 . As shown in (b), the tube for NO is inserted between the supporting member  12   c   2  and the pinch member  12   b,  the tube for NC is inserted over the tube for NO, and the supporting members  12   c   1  and  12   c   2  are combined. In such a state, the tubes may be prepared as the tube set. If a snap-fit structure is adopted as a method for the combination, inexpensive and easy combination is possible. When the pinch valve  12  is used, as shown in (c), the supporting member  12   c   2  and the pinch valve main body  12   a  are combined and the pinch member  12   b  and the actuator  12   d  are combined. Note that, in the combination of the pinch member  12   b  and the actuator  12   d,  up-down movements of the actuator have be able to be transmitted to the pinch member. For example, a snap-fit is desirably adopted in which a projecting section is fit in a recessed section and a positional relation between the projecting section and the recessed section is restrained. 
         [0043]    Note that the flow path treated in the present invention is not limited to a circular tube structure . Besides the tube, the present invention can also be applied to, for example, a flow path formed by sticking together films. The flow path only has to be a flow path deformable with respect to a pinch force of the pinch valve and having elasticity or flexibility. 
       Second Embodiment 
       [0044]    An embodiment explained below is an example in which the flow-path control method is applied to a cell culture device. 
         [0045]    Among cell culture devices, there is a cell culture device that connects a supply bag or a collection bag, in which a culture medium is stored, to a closed culture vessel including a lead-in port and a discharge port for fluid to form one closed system (hereinafter, closed culture system) and performs culture medium exchange on the inside of the system to cultivate a cell. A method of the cell culture device is described in, for example, Patent Literature 2 described above. Since the system is the closed system, there is an advantage that there is no risk of contamination from the outside. However, there is a limitation that control of liquid has to be basically performed from the outside of the system. The pinch valve can be controlled from the outside of the system. Therefore, the pinch valve is a control member suitable for this device. 
         [0046]    The closed culture system is shown in  FIG. 8 . A supply bag  14  and a collection bag  15  are connected to a culture vessel  13 , which includes an inlet and an outlet, via tubes (an upstream side  16  and a downstream side  17 ) . The culture vessel  13  is in a closed state. A driving force for liquid needs to be applied from the outer side . The tube is squeezed from the outer side by a squeezing pump  18  to feed the liquid. Note that the squeeze pump  18  may be set in any one of the tubes on the upstream side and the downstream side. 
         [0047]    When singularities of the culture vessel, the supply bag, and the collection bag are present and a branch is absent, as shown in  FIG. 8 , it is unnecessary to control a flow path. However, when pluralities of the culture vessels, the supply bags, and the collection bags are present and connected in parallel, the liquid has to be fed while selecting a flow path. The flow-path selection method of the present invention is applied to the selection of the flow path. 
         [0048]    An example in which the supply bags are connected in parallel is shown in  FIG. 9 ( a ) . As liquid types necessary for cell culture, there are a cell suspension, a culture medium, cleaning liquid, oxygen liquid, and the like. The cell culture device desirably can simultaneously treat a plurality of supply bags. A plurality of supply bags  14  are respectively connected to a common flow path  16  by individual flow paths  19 . A flow-path selecting mechanism  20  is placed in a place where the individual flow paths  19  are arranged side by side. The flow-path selecting mechanism  20  is a mechanism including N number of universal-type pinch valves and is a mechanism capable of selecting 2 N  number of flow paths. The flow-path selecting mechanism  20  controls the flow paths such that any one of the flow paths is opened. 
         [0049]    A peristaltic pump  18  is set in an upstream or downstream common flow path portion. After the flow path is selected, by driving the peristaltic pump, a selected liquid type is sent to the culture vessel. 
         [0050]      FIG. 9( b )  is an example in which a plurality of culture vessels are present and connected in parallel. Culture vessels are often increased to increase a yield. A plurality of cells are cultivated to serve for an inspection separately from cells for transplanting. A plurality of culture vessels  13  are placed in parallel and respectively connected to a common flow path by individual flow paths  21 . If the flow-path selecting mechanism  20  is placed in a place where the individual flow paths  21  are arranged side by side, it is possible to select a culture vessel to which liquid is sent. The flow-path selecting mechanism  20  may be set on an upstream side of the culture vessel or may be set on a downstream side of the culture vessel. 
         [0051]      FIG. 9( c )  is an example in which a plurality of collection bags are present and connected in parallel. When it is desired to separate a collected object, such a connection method can be used. If a common flow path  17  branches to individual flow paths  22  and the flow-path selecting mechanism  20  is set in a place where the common flow path  17  branches, it is possible to select a collection destination. 
         [0052]    The connection methods explained above may be combined as shown in  FIG. 9( d ) . For example, pluralities of supply bags  14 , culture vessels  13 , and collection bags  15  are present and connected via upper and lower common paths  16  and  17 . If the flow-path selecting mechanisms  20  are set in places of respective individual flow paths, it is possible to feed any liquid type to any culture vessel and collect the liquid type in any collection destination. 
         [0053]    As shown in  FIG. 9( e ) , M number of supply bags and N number of culture vessels are connected in M×N combinations. Although flow paths are complicated, since the flow paths are not shared, there is an advantage that carryovers of different liquid types do not occur upstream. M number of supply bags  14  and N number of culture vessels  13  are connected to each other by (M×N) number of individual flow paths  23 . The flow-path selecting mechanism  20  only has to be set in a place of the individual flow paths  23 . Note that, even if the number of flow paths is large on the upstream side, if the flow paths are collected as one flow path on the downstream side, only one driving source (squeezing pump) has to be provided. 
         [0054]    When it is desired to separate a plurality of collected objects from the culture vessel, if carryovers should not be present in the collected objects at all, the collected objects maybe divided on the collection side as shown in (f). P number of culture vessels  13  and Q number of collection bags  15  are connected to each other by (P×Q) number of individual flow paths  24 . The flow-path selecting mechanism  20  only has to be set in a place of the individual flow paths  24 . If the flow paths on the upstream side are collected as one flow path, only one driving source has to be provided. 
       Third Embodiment 
       [0055]    An embodiment explained below is an example in which the flow-path control method is applied to an automatic analysis device. 
         [0056]    In the automatic analysis device, there is, for example, a reagent dispensing system shown in  FIG. 10 . A flow path  32  leading to a reagent container  31  is connected to one side of a three-way switching valve  30 . A flow path  34  leading to a nozzle  33  is connected to the other side of the three-way switching valve  30 . A common port of the three-way switching valve  30  is connected to a syringe  36  via a flow path  35 . When the three-way switching valve  30  is directed to the reagent container  31  side and the syringe  36  is pulled, it is possible to suck a reagent to the syringe side. When the three-way switching valve  30  is switched to the nozzle  33  side and the syringe  36  is pushed, it is possible to discharge the reagent from the nozzle. 
         [0057]    To treat a plurality of reagent, the automatic analysis device only has to include a plurality of the reagent dispensing systems. However, as a method of controlling the reagents with one syringe, there is a method of controlling the reagents using a multiple switching valve. The method is described in, for example, Patent Literature 1 described above. Flow paths of a plurality of reagent dispensing systems are connected to one side of the multiple switching valve, a syringe is connected to the other side of the multiple switching valve, and the reagent dispensing system is selected to control the syringe. Consequently, it is possible to dispense any reagent. 
         [0058]    In the multiple switching valve described in Patent Literature 1, slide valves are pressed against each other to be switched. Therefore, the slide valves are switched without a leak. However, because of the pressing structure, a leak from the pressed portion is not zero. In order to reduce the leak as much as possible, maintenance is extremely important and time-consuming. 
         [0059]    As shown in  FIG. 11 , the flow paths  35  extending from common ports of three-way switching valves of a plurality of reagent dispensing systems are collected as a common flow path  37 . A common syringe  38  is connected to the common flow path  37 . The flow-path selecting mechanism  20  of the present invention is set in a place of the plurality of individual flow paths  35 . By operating the syringe  38  after selecting a flow path with the flow-path selecting mechanism  20 , it is possible to dispense any reagent. With this method, since the reagent dispensing systems remain as close systems, a leak could not occur. There is an advantage that maintenance is easy. 
       REFERENCE SIGNS LIST 
       [0060]      1  tube 
         [0061]      2  pinch valve 
         [0062]      3  pinch member 
         [0063]      4  movable core 
         [0064]      5  supporting member 
         [0065]      6  case 
         [0066]      7  spring 
         [0067]      8  coil 
         [0068]      9  fixed core 
         [0069]      10  tube holder 
         [0070]      11  tube holder 
         [0071]      12  pinch valve 
         [0072]      13  culture vessel 
         [0073]      14  supply bag 
         [0074]      15  collection bag 
         [0075]      16  upstream side tube 
         [0076]      17  downstream side tube 
         [0077]      18  squeezing pump 
         [0078]      19  individual flow path 
         [0079]      20  flow-path selecting mechanism 
         [0080]      21  individual flow path 
         [0081]      22  individual flow path 
         [0082]      23  individual flow path 
         [0083]      24  individual flow path 
         [0084]      30  three-way switching valve 
         [0085]      31  reagent container 
         [0086]      32  flow path 
         [0087]      33  nozzle 
         [0088]      34  flow path 
         [0089]      35  flow path 
         [0090]      36  syringe 
         [0091]      37  common flow path 
         [0092]      38  syringe