Patent Description:
In a blood purification device having a roller pump in which a pump tube constituting a part of a liquid circuit is held by a tube receiver and in which the pump tube is pressed with a roller so that a liquid inside the pump tube is delivered, a method of occluding and releasing the pump tube by pressing the tube receiver against the roller is being used (for example, see Patent Document <NUM>).

Further, in a blood purification device, a plurality of roller pumps are often used. For such cases, it has been suggested to drive and control the individual roller pumps with separate control devices (for example, see Patent Document <NUM>).

In a blood purification device, in addition to operations of priming the liquid circuit and performing hemodialysis, an operation such as calibration of the pump discharge flow rate may be performed. In that case, it is necessary to configure a liquid circuit for the special operation by blocking a part of the liquid circuit or allowing a part of the liquid circuit to be bypassed. Conventionally, a liquid circuit required for an operation is often configured by manually opening and closing a liquid circuit using a valve.

Meanwhile, in a blood purification device, several pumps are often used as described in Patent Document <NUM>, and accordingly, the number of times of the opening and closing of the liquid circuit is increased. It is therefore desired that a liquid circuit necessary for an operation be configured not manually but automatically by the blood purification device.

As a method to that end, there might be considered, for example, a method of opening and closing a pump tube by pressing a tube receiver of a roller pump against a roller as described in Patent Document <NUM>. However, when the number of pumps and the number of liquid circuits are increased, a pump tube opening/closing control mechanism must be provided for every pump, and this results in the problem that the device configuration becomes complicated.

In view of the above, the present invention is directed to carrying out opening and closing of a liquid circuit in a blood purification device by means of a simple configuration.

A blood purification device according claim <NUM> is provided to solve the problem. The device comprises: a tube receiving plate that holds an elastic pump tube; a tube pressing member driving unit which is positioned facing the tube receiving plate across the pump tube, and which causes a tube pressing member to be moved with respect to the tube receiving plate; and a pump tube opening/closing mechanism that causes the tube pressing member driving unit and the tube receiving plate to advance and retract relative to each other, and thereby carries out closing and opening of the pump tube which is positioned between the tube pressing member and the tube receiving plate.

In this way, since the pump tube is opened and closed by causing the tube pressing member driving unit to advance and retract relative to the tube receiving plate by means of the pump tube opening/closing mechanism, the opening and closing of the liquid circuit can be carried out with a simple configuration.

In the blood purification device of the present invention, the pump tube opening/closing mechanism may comprise a cam that causes the tube pressing member driving unit to advance toward the tube receiving plate, and a retraction mechanism that causes the tube pressing member driving unit to retract from the tube receiving plate.

With this arrangement, opening and closing of a liquid circuit can be carried out with a simple configuration comprising the cam and the retraction mechanism.

In the blood purification device of the present invention, the tube receiving plate may hold a plurality of pump tubes, and a plurality of tube pressing member driving units may be provided. The pump tube opening/closing mechanism may comprise: a plurality of cams that cause the plurality of tube pressing member driving units to advance toward the tube receiving plate; a common cam driving unit that rotates and drives the plurality of cams; and a plurality of retraction mechanisms that cause the plurality of tube pressing member driving units to retract from the tube receiving plate. The pump tube opening/closing mechanism may cause the cam driving unit to drive the plurality of cams so that the plurality of tube pressing member driving units are caused to advance and retract with respect to the tube receiving plate, and thereby carry out closing and opening of the plurality of pump tubes, which are positioned between the plurality of tube pressing members of the plurality of tube pressing member driving units and the tube receiving plate.

Since the closing and opening of the plurality of pump tubes can be performed by causing the common cam driving unit to drive the plurality of cams, opening and closing of a large number of liquid circuits can be carried out with a simple configuration.

In the blood purification device of the present invention, the plurality of cams may have shapes corresponding to combinations of open and closed states of the plurality of pump tubes.

According to this arrangement, various liquid circuits can be configured by combining various types of cams, and the blood purification device can be operated in various operation patterns.

The blood purification device of the present invention may comprise a device main body inside of which the tube pressing member driving unit and the pump tube opening/closing mechanism are arranged, and the tube receiving plate may be a plate located facing the device main body. Further, the blood purification device may comprise a cassette that is detachably mounted to the device main body, wherein the cassette includes a casing, which contains a dialyzer, a dialysate regeneration column, and a water removal container, and wherein the tube receiving plate is a plate of the casing that is located facing the device main body.

In the blood purification device comprising the cassette integrating a liquid-contacting section and the device main body, the opening and closing of the pump tube are carried out by arranging the tube pressing member driving unit and the pump tube opening/closing mechanism, which are non-liquid-contacting sections, in the nondisposable device main body, while the cassette integrating the liquid-contacting section is configured disposable. With this arrangement, handling of the blood purification device can be simplified, and the opening and closing of the liquid circuit can be performed with a simple configuration.

In the blood purification device of the present invention, the pump tube opening/closing mechanism may include a cam that causes the tube receiving plate to advance toward the tube pressing member driving unit, and a retraction mechanism that causes the tube receiving plate to retract from the tube pressing member driving unit. Further, in the blood purification device of the present invention, the tube receiving plate may hold a plurality of pump tubes, and a plurality of tube pressing member driving units may be provided. The cam of the pump tube opening/closing mechanism may cause the tube receiving plate to advance toward the plurality of tube pressing member driving units, and thereby carry out closing and opening of the plurality of pump tubes, which are positioned between the plurality of tube pressing members of the plurality of tube pressing member driving units and the tube receiving plate.

In the blood purification device of the present invention, the retraction mechanism may be a retraction spring, and the tube pressing member may be composed of a plurality of fingers.

In the blood purification device of the present invention, the pump tube opening/closing mechanism may include a cam that causes the tube pressing member driving unit to advance toward the tube receiving plate via a cam follower which is attached to the tube pressing member driving unit via an elastic member, and a retraction mechanism that causes the tube pressing member driving unit to retract from the tube receiving plate.

By adopting a configuration as described above in which the cam follower is attached to the tube pressing member driving unit via the elastic member, and in which the tube pressing member driving unit is caused to advance toward the tube receiving plate via this cam follower, the closing and opening of the pump tube can be performed reliably even without accurate adjustment of the advancing distance of the tube pressing member driving unit.

According to the present invention, the tube receiving plate may hold a plurality of pump tubes, and a plurality of tube pressing member driving units may be provided. The pump tube opening/closing mechanism may comprise: a plurality of cams which abut cam followers respectively attached to the plurality of tube pressing member driving units via elastic members and which cause the plurality of tube pressing member driving units to advance toward the tube receiving plate; a common cam driving unit that rotates and drives the plurality of cams; and a plurality of retraction mechanisms that cause the plurality of tube pressing member driving units to retract from the tube receiving plate. The pump tube opening/closing mechanism may cause the cam driving unit to drive the plurality of cams so that the plurality of tube pressing member driving units are caused to advance and retract with respect to the tube receiving plate, and thereby carries out closing and opening of the plurality of pump tubes, which are positioned between the plurality of tube pressing members of the plurality of tube pressing member driving units and the tube receiving plate. The plurality of cams may have shapes corresponding to combinations of open and closed states of the plurality of pump tubes. Further, in the blood purification device of the present invention, when the pump tube opening/closing mechanism closes the pump tube, a front end of the tube pressing member driving unit may abut a surface of the tube receiving plate.

Since the closing and opening of the plurality of pump tubes can be performed by driving the plurality of cams with the common cam driving unit, closing and opening of a large number of liquid circuits can be carried out with a simple configuration. Further, various liquid circuits can be configured by combining various types of cams, and the blood purification device can be operated in various operation patterns.

The blood purification device of the present invention may comprise a device main body inside of which the tube pressing member driving unit and the pump tube opening/closing mechanism are arranged, and a cover attached facing the device main body. The tube receiving plate may be attached to the cover via another elastic member.

According to the present configuration, the closing and opening of the pump tubes can be performed reliably even without accurate adjustment of the advancing distance of the tube pressing member driving units.

In the blood purification device of the present invention, a plurality of tube pressing member driving units may be provided. The cover may have a plurality of recesses at positions facing the tube pressing members of the tube pressing member driving units. In each of the recesses, a tube receiving plate may be mounted via an elastic member, and each of the tube receiving plates may hold a corresponding pump tube. The pump tube opening/closing mechanism may comprise: a plurality of cams that cause the plurality of tube pressing member driving units to advance toward the tube receiving plates; a common cam driving unit that rotates and drives the plurality of cams; and a plurality of retraction mechanisms that cause the plurality of tube pressing member driving units to retract from the tube receiving plates. The pump tube opening/closing mechanism may cause the cam driving unit to drive the plurality of cams so that the plurality of tube pressing member driving units are caused to advance and retract with respect to the tube receiving plates, and thereby carry out closing and opening of the plurality of pump tubes, which are positioned between the plurality of tube pressing members of the plurality of tube pressing member driving units and the tube receiving plates. The plurality of cams may have shapes corresponding to combinations of open and closed states of the plurality of pump tubes. Further, in the blood purification device of the present invention, the elastic members and said other elastic member may be composed of springs.

Accordingly, with a simple configuration, the closing and opening of the pump tubes can be performed reliably even without accurate adjustment of the advancing distance of the tube pressing member driving units.

The blood purification device of the present invention may include a cam follower attached to the tube pressing member driving unit via an elastic member, and the cam may cause the tube receiving plate to advance toward the tube pressing member driving unit via the cam follower. The tube receiving plate and the tube pressing member driving unit may be connected via another elastic member. Further, the elastic member and said other elastic member may be composed of springs.

According to this configuration, the closing and opening of the pump tube can be performed reliably even without accurate adjustment of the advancing distance of the tube pressing member driving unit.

The present invention enables to carry out opening and closing of a liquid circuit in a blood purification device by means of a simple configuration.

A blood purification device <NUM> according to an embodiment is described below by reference to the drawings. The blood purification device <NUM> comprises a device main body <NUM>, and a cover <NUM> attached to the device main body <NUM> in a manner capable of being opened and closed. In the following description, the direction in which the device main body <NUM> and the cover are arranged will be referred to as the front-rear direction, the direction orthogonal to the front-rear direction in a horizontal plane will be referred to as the width direction, and the upright direction will be referred to as the vertical direction.

As shown in <FIG> and <FIG>, the device main body <NUM> includes a housing <NUM>, finger driving units <NUM> which are a plurality of tube pressing member driving units received inside the housing <NUM>, a common pump tube opening/closing mechanism <NUM>, and a common control unit <NUM>.

As shown in <FIG> and <FIG>, each of the finger driving units <NUM> (20a-20c) comprises a finger casing <NUM> (14a-14c) and a drive motor <NUM> (17a-17c). Each finger casing <NUM> (14a-14c) has a finger support portion <NUM> (21a-21c). The finger support portion <NUM> (21a-21c) supports fingers <NUM> (15a-15c), which are tube pressing members arranged in a plurality of rows in the vertical direction, in a front part of the finger casing <NUM> (14a-14c) in such a manner that the fingers <NUM> are movable in the front-rear direction of the device main body <NUM> while being housed inside the housing <NUM> of the device main body <NUM>. In the front surface of each finger casing <NUM> (14a-14c), a V-shaped tube receiving groove <NUM> (24a-24c) is formed extending vertically. Here, the tube receiving grooves <NUM> may alternatively be not provided. Instead of the V-shaped grooves, plate-shaped guides extending in the vertical direction may be provided so as to prevent twisting of pump tubes 41a-41c (described further below).

The respective drive motors <NUM> (17a-17c) drive the fingers <NUM> (15a-15c), which are the tube pressing members, in the front-rear direction of the device main body <NUM>. The drive motors <NUM> are connected to the control unit <NUM> and are operated according to commands from the control unit <NUM>.

As shown in <FIG> and <FIG>, the housing <NUM> includes: a base <NUM>; a rear plate 11a provided upright toward the rear end of the base <NUM>; side plates 11b provided upright on both sides in the width direction of the base <NUM>; a width plate 13b provided upright toward the front end of the base <NUM>; a front plate 13c covering an upper part of the front side of the device main body <NUM>; and a ceiling plate 13d. As shown in <FIG>, a plurality of ribs 13a extending in the front-rear direction are provided on the upper surface of the base <NUM>.

As shown in <FIG>, the pump tube opening/closing mechanism <NUM> includes: a casing guide <NUM> that supports the finger casings <NUM> (14a-14c) in a manner slidable in the front-rear direction; rotary cams <NUM> (53a-53c) that cause the finger driving units <NUM> (20a-20c) to advance toward the cover <NUM>; coil springs <NUM> which are retraction springs constituting a retraction mechanism that causes the finger driving units <NUM> (20a-20c) to retract from the cover <NUM>; and a motor <NUM> that rotates and drives the rotary cams <NUM> (53a-53c).

The casing guide <NUM> includes a plurality of support plates 51a, guide bars 51b, and connecting members 51c. As shown in <FIG> and <FIG>, the support plates 51a are plate members extending in a longitudinal direction, which are attached to the upper ends of the plurality of ribs 13a provided on the upper surface of the base <NUM>, and which support the bottom surfaces of the lower corners of the finger casings <NUM> (14a-14c). The guide bars 51b are plate members provided upright on the upper surfaces of the support plates 51a and extending in the longitudinal direction, which guide the side surfaces of the lower corners of the finger casings <NUM> (14a-14c) in the front-rear direction. The connecting members 51c are plate members that connect between the support plates 51a in the width direction. As shown in <FIG>, each of the support plates 51a located at the two widthwise ends supports the bottom surface of a lower corner of one finger casing <NUM> (14a or 14c), and each of the guide bars 51b provided upright on the upper surfaces of these support plates 51a located at the two widthwise ends guides a side surface of one finger casing <NUM> (14a or 14c) in the front-rear direction. Further, each of the two central support plates 51a supports the bottom surfaces of lower corners of two adjacent finger casings <NUM> (14a-14c), and each of the guide bars 51b provided upright on the upper surfaces of these two central support plates 51a guides side surfaces of two adjacent finger casings <NUM> (14a-14c) in the front-rear direction. Here, the casing guide <NUM> may be any member that guides the finger casings <NUM> (14a-14c) in the front-rear direction, and is not limited to the above-described configuration.

As shown in <FIG> and <FIG>, at both widthwise side portions of a lower part of the rear surface of each finger casing <NUM> (14a-14c), pins 52a are attached, to each of which one end of the respective coil spring <NUM> is to be mounted. Further, pins 52b are attached to the rear plate 11a of the device main body <NUM> at positions facing the respective pins 52a. The coil springs <NUM> are mounted between the pins 52a and the pins 52b. Here, the finger casings <NUM> (14a-14c) and the rear plate 11a may alternatively be connected directly by the coil springs <NUM> without using the pins 52a and 52b.

As shown in <FIG> and <FIG>, at both widthwise side portions of the rear plate 11a of the device main body <NUM>, brackets <NUM> are attached, which rotatably support a shaft <NUM> to which the rotary cams <NUM> (53a-53c) are mounted. A pulley <NUM> is attached to one end of the shaft <NUM>, while a collar <NUM> is attached to the other end. At a portion of the rear plate 11a above the brackets <NUM>, a bracket <NUM> is attached, and the motor <NUM> is fixed to the bracket <NUM>. A pulley <NUM> is attached to a shaft <NUM> of the motor <NUM>. The pulley <NUM> attached to the shaft <NUM> of the motor <NUM> and the pulley <NUM> attached to the shaft <NUM> to which the rotary cams <NUM> (53a-53c) are mounted are connected by a belt <NUM>. The motor <NUM> is connected to the control unit <NUM> and is operated according to commands from the control unit <NUM>. The motor <NUM>, the pulleys <NUM> and <NUM>, the belt <NUM>, and the shaft <NUM> constitute a common cam driving unit that drives the plurality of rotary cams <NUM> (53a-53c).

As shown in <FIG> and <FIG>, at both widthwise side portions of a central part, in the vertical direction, of the rear surface of each finger casing <NUM> (14a-14c), two posts 54p are attached. Between the pairs of posts 54p, plate-shaped cam followers 54a-54c are mounted, which are abutted by the rotary cams <NUM> (53a-53c). Here, alternatively, the posts 54p and the cam followers 54a-54c may be not provided, and the rotary cams <NUM> may be configured to contact the rear surfaces of the finger casings <NUM> (14a-14c).

As shown in <FIG> and <FIG>, the cover <NUM> is a flat plate member, and has the pump tubes 41a-41c mounted on its flat surface 30a located toward the device main body <NUM> (i.e., located toward the rear). The two ends of the pump tubes 41a-41c are connected to a blood circuit <NUM> and a dialysate circuit <NUM> shown in <FIG>. The surfaces of the pump tubes 41a-41c located toward the cover <NUM> are arranged along the flat surface 30a of the cover <NUM>. As such, the cover <NUM> constitutes a tube receiving plate that holds the pump tubes <NUM> (41a-41c). In <FIG>, <FIG>, <FIG> and <FIG>, illustration of a dialysate regeneration column <NUM> provided in the dialysate circuit <NUM> is omitted. The dialysate regeneration column <NUM> may be provided at any position in the dialysate circuit <NUM>.

When the cover <NUM> is closed, as shown in <FIG>, the pump tubes <NUM> (41a-41c) are received in the tube receiving grooves <NUM> (24a-24c) of the finger casings <NUM> (14a-14c), and the finger driving units <NUM> (20a-20c) are arranged facing the cover <NUM> across the pump tubes <NUM> (41a-41c). Here, the cover <NUM> need not be a flat plate member so long as the cover <NUM> has sufficient hardness for collapsing the pump tubes <NUM> (41a-41c) in cooperation with the fingers 15a-15c.

When the motor <NUM> of the pump tube opening/closing mechanism <NUM> is rotated, the rotary cams <NUM> (53a-53c) are rotated via the pulleys <NUM>, <NUM> and the belt <NUM>. When the rotary cams <NUM> (53a-53c) are rotated and come into contact with the cam followers 54a-54c attached to the finger casings <NUM> (14a-14c), the cam followers 54a-54c are pushed forward toward the cover <NUM>. When the cam followers 54a-54c are pushed forward, the finger casings <NUM> (14a-14c) are moved toward the cover <NUM> while being guided by the guide bars 51b of the casing guide <NUM>. When the finger casings <NUM> (14a-14c) are moved toward the cover <NUM>, the fingers <NUM> (15a-15c) are moved toward the cover <NUM>, to thereby sandwich the pump tubes <NUM> (41a-41c) between the fingers <NUM> (15a-15c) and the cover <NUM>, and to press the pump tubes <NUM> (41a-41c) against the surface 30a of the cover <NUM>, so that the pump tubes <NUM> (41a-41c) become closed. At that time, the coil springs <NUM> are stretched out in the front-rear direction.

While in this state, when the drive motors <NUM> (17a-17c) of the finger driving units <NUM> (20a-20c) are rotated, the fingers <NUM> (15a-15c) arranged in a plurality of rows in the vertical direction are sequentially moved in the direction of approaching and moving away from the cover <NUM>, so that liquid inside the pump tubes <NUM> (41a-41c) is delivered.

Further, when the rotary cams <NUM> are moved away from the cam followers 54a-54c, the coil springs <NUM> pull the pins 52a back toward the rear plate 11a of the housing <NUM>. As a result, the finger casings <NUM> (14a-14c) are moved toward the rear of the device main body <NUM> so as to move away from the cover <NUM>, while being guided by the guide bars 51b of the casing guide <NUM>. When the finger casings <NUM> (14a-14c) are moved rearward, the fingers <NUM> (15a-15c) are moved in the direction away from the cover <NUM>, and the fingers <NUM> (15a-15c) are moved out of contact with the surface of the pump tubes <NUM> (41a-41c), so that the pump tubes <NUM> (41a-41c) become opened.

<FIG> shows the rotary cams 53a-53c mounted to the shaft <NUM>. In <FIG>, dash-dotted lines indicate the counterclockwise rotation angles of the shaft <NUM> and the rotary cams 53a-53c. The state shown in <FIG> is the initial position of the shaft <NUM> and the rotary cams 53a-53c.

As shown in <FIG>, in the <NUM>° rotation angle position, the rotary cams 53a and 53b have a small radius, and the cam followers 54a and 54b are placed in the rear open position. In the <NUM>° and <NUM>° rotation angle positions, the rotary cams 53a and 53b have a large radius, and the cam followers 54a and 54b are placed in the front closed position as shown in <FIG>. Further, in the <NUM>° rotation angle position, the rotary cam 53c has a large radius, and the cam follower 54c is placed in the front closed position as shown in <FIG>. When in the <NUM>° and <NUM>° rotation angle positions, the rotary cam 53c has a small radius, and the cam follower 54c is placed in the rear open position as shown in <FIG>, <FIG>, and <FIG>. As such, the rotary cams 53a-53c have shapes according to combinations of open and closed states of the pump tubes 41a-41c.

When the blood purification device <NUM> is in a stopped state, the shaft <NUM> is in the initial position in which, as shown in <FIG>, the <NUM>° position is located facing the cam followers 54a-54c, and all of the cam followers 54a-54c are in the rear open position. In this state, the fingers 15a-15c of a dialysate outlet pump DPO, a blood pump BP, and a dialysate inlet pump DPI are located away from the respective pump tubes 41a-41c, as shown by dash-dotted lines in <FIG> and <FIG>.

As shown in <FIG>, in a dialysis operation, the dialysate outlet pump DPO and the dialysate inlet pump DPI are to be driven to circulate dialysate to a dialyzer <NUM> and a water removal container <NUM> in the dialysate circuit <NUM>. Further, the blood pump BP is to be driven to cause blood from a human body to be delivered from a blood circuit inlet 91a to the dialyzer <NUM> and a drip chamber <NUM> in the blood circuit <NUM>, and to be returned to the human body via a blood circuit outlet 91b. As such, in the dialysis operation, liquid delivering operation is to be carried out by the three pumps; namely, the dialysate outlet pump DPO, the dialysate inlet pump DPI, and the blood pump BP.

To this end, when performing the dialysis operation, the control unit <NUM> drives the motor <NUM> of the pump tube opening/closing mechanism <NUM> so as to rotate the shaft <NUM> by <NUM>° from the initial position, to the position shown in <FIG>. As shown in <FIG>, when the shaft <NUM> is rotated by <NUM>° from the initial position, the rotary cams 53a-53c are also rotated by <NUM>° from the initial position, and all of the rotary cams 53a-53c push the cam followers 54a-54c forward into the front closed position. The finger casings 14a-14c are thereby moved forward. As a result, at least one finger 15a among the plurality of fingers 15a arranged in a plurality of rows in the vertical direction presses the pump tube 41a against the surface 30a of the cover <NUM>, and closes the pump tube 41a. Similarly, at least one finger 15b and at least one finger 15c among the plurality of fingers 15b and 15c press the pump tubes 41b and 41c against the surface 30a of the cover <NUM>, and close the pump tubes 41b and 41c. As a result, the pump tubes 41a, 41b, and 41c are placed in the closed state, and the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI are placed in a state capable of delivering liquid.

Subsequently, the control unit <NUM> causes the drive motors 17a-17c of the finger driving units 20a-20c to rotate at a predetermined rotation speed. As a result, the fingers 15a-15c are sequentially moved in the direction of approaching and moving away from the cover <NUM>, and a predetermined amount of liquid is delivered from the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI. As shown in <FIG>, the dialysate outlet pump DPO and the dialysate inlet pump DPI cause the dialysate to circulate through the dialyzer <NUM> and the water removal container <NUM> in the dialysate circuit <NUM>, while the blood pump BP causes the blood from the human body to be delivered from the blood circuit inlet 91a to the dialyzer <NUM> and the drip chamber <NUM> in the blood circuit <NUM> and to be returned to the human body via the blood circuit outlet 91b.

In the blood purification device <NUM>, priming is performed before the dialysis operation by, for example, circulating a physiological saline solution in the dialysate circuit <NUM> and the blood circuit <NUM>. In priming the dialysate circuit <NUM>, as shown in <FIG>, the pump tube 41c of the dialysate inlet pump DPI is to be opened, and the priming solution is to be circulated to the dialysate circuit <NUM> using the dialysate outlet pump DPO.

To this end, when performing the priming, the control unit <NUM> drives the motor <NUM> of the pump tube opening/closing mechanism <NUM> so as to rotate the shaft <NUM> by <NUM>° from the initial position to the position shown in <FIG>. In the state shown in <FIG>, the rotary cams 53a and 53b push the cam followers 54a and 54b forward to the closed position. On the other hand, the rotary cam 53c does not push the cam follower 54c forward, and the cam follower 54c that abuts the rotary cam 53c is in the rear open position. As a result, the finger casings 14a and 14b are moved forward, and the fingers 15a and 15b press the pump tubes 41a and 41b against the cover <NUM>, so that the dialysate outlet pump DPO and the blood pump BP are placed in a state capable of delivering liquid. Meanwhile, the finger casing 14c is not moved forward, so that the fingers 15c are located away from the pump tube 41c, and the pump tube 41c of the dialysate inlet pump DPI is in the open state.

During the priming operation performed on the dialysate side, the blood circuit outlet 91b is closed by a valve <NUM> so that the priming solution is circulated in only the dialysate circuit <NUM>. The control unit <NUM> rotates only the drive motor 17a of the finger driving unit 20a at a predetermined rotation speed. As a result, as in the above-described operation, a predetermined amount of liquid is delivered from the dialysate outlet pump DPO. As shown in <FIG>, the dialysate outlet pump DPO causes the priming solution to be circulated through the dialyzer <NUM>, the water removal container <NUM>, and the pump tube 41c of the dialysate circuit <NUM>.

In the blood purification device <NUM>, calibration of the liquid delivery amount of the blood pump BP may be performed. In that case, for example, a calibration liquid bag <NUM> containing a physiological saline solution or the like is connected to the blood circuit inlet 91a of the blood circuit <NUM>, and the blood circuit outlet 91b is closed by the valve <NUM>, as shown in <FIG>. The pump tube 41a of the dialysate outlet pump DPO is to be closed while the pump tube 41c of the dialysate inlet pump DPI is opened, and the blood pump BP is to be driven so that the calibration liquid flows from the calibration liquid bag <NUM> through the dialyzer <NUM> and from the pump tube 41c of the dialysate inlet pump DPI to the water removal container <NUM>. The weight of the water removal container <NUM> is detected by a weight detection unit <NUM> of the water removal container <NUM> so as to measure the liquid delivery amount of the blood pump BP. Based on this measurement, the liquid flow rate of the blood pump BP is to be calibrated.

To this end, when calibrating the liquid delivery amount of the blood pump BP, the control unit <NUM> drives the motor <NUM> of the pump tube opening/closing mechanism <NUM> so as to rotate the shaft <NUM> by <NUM>° from the initial position to the position shown in <FIG>. As a result, as in the operation described above by reference to <FIG>, the dialysate outlet pump DPO and the blood pump BP are placed in a state capable of delivering liquid, and the pump tube 41c of the dialysate inlet pump DPI is opened.

Subsequently, the control unit <NUM> rotates the drive motor 17b of the finger driving unit 20b at a predetermined rotation speed, and a predetermined amount of liquid is thereby delivered from the blood pump BP, similar to the case of the above-described operation. Since the drive motor 17a is in the stopped state, the fingers 15a of the dialysate outlet pump DPO are in a state of closing the pump tube 41a. As shown in <FIG>, the blood pump BP delivers the calibration liquid from the calibration liquid bag <NUM> through the dialyzer <NUM>, and from the pump tube 41c of the dialysate inlet pump DPI to the water removal container <NUM>. Based on a drive command value transmitted to the blood pump BP and a delivered liquid weight detected by the weight detection unit <NUM> of the water removal container <NUM>, calibration of the blood pump BP is carried out.

As described above, in the blood purification device <NUM> of the present embodiment, the rotary cams 53a-53c have shapes corresponding to the combinations of open and closed states of the pump tubes 41a-41c necessary for the various operations of the blood purification device <NUM>. Accordingly, by driving the single motor <NUM> of the pump tube opening/closing mechanism <NUM>, the three finger casings <NUM> (14a-14c) can be caused to advance and retract with respect to the cover <NUM> so as to close and open the pump tubes <NUM> (41a-41c), and the dialysate circuit <NUM> and the blood circuit <NUM> can thereby be opened and closed in various patterns. In this way, in the blood purification device <NUM> including a plurality of pumps such as the dialysate outlet pump DPO, the dialysate inlet pump DPI, and the blood pump BP, various operations can be performed by a simple method.

In the blood purification device, there are cases in which the pump tubes 41a-41c are reused. Here, the term "reuse" means that consumables are not discarded after one blood purification treatment is completed, but are washed and disinfected as necessary and then used again for the next treatment. When the pump tubes 41a-41c are reused, the liquid delivery amount may become changed due to degradation caused by use.

In the blood purification device <NUM> of the present embodiment, as described by reference to <FIG>, calibration of the blood pump BP can be performed by driving the motor <NUM> of the pump tube opening/closing mechanism <NUM> to thereby close the pump tubes 41a and 41b and to place the pump tube 41c in the open state, and delivering a predetermined amount of liquid from the blood pump BP. Accordingly, even when the pump tube 41b is degraded by reuse, the blood pump BP can be easily calibrated to correct the flow rate.

Further, in the blood purification device <NUM> of the present embodiment, as described by reference to <FIG>, the pump tubes 41a-41c can be opened and prevented from being subjected to a pressing force while in the stopped state. It is thereby possible to suppress degradation of the pump tubes 41a-41c due to use.

Furthermore, in the blood purification device <NUM> of the present embodiment, the opening and closing of the pump tubes <NUM> (41a-41c) are carried out by causing the finger driving units <NUM> (20a-20c) housed in the device main body <NUM> to advance and retract with respect to the cover <NUM> by means of the pump tube opening/closing mechanism <NUM> housed in the device main body <NUM>. Accordingly, even when the pump tubes <NUM> (41a-41c) are arranged in the cover <NUM> where it is difficult to mount a mechanism for moving the pump tubes <NUM> (41a-41c), opening and closing of the liquid circuit can be carried out with a simple configuration.

In the above-described embodiment, the rotary cams 53a-53c are described as having shapes that can set the open and closed states of the pump tubes 41a-41c corresponding to the stopped state, the dialysis operation, the priming operation, and the blood pump BP calibration operation of the blood purification device <NUM>. However, the shapes of the rotary cams 53a-53c are not limited thereto, and may also be those that correspond to combinations of open and closed states of the pump tubes 41a-41c required for other operations. For example, when rotation angle positions are assigned at intervals of <NUM>° as in the case of the rotary cams 53a-53c described above, six patterns of rotary cams as shown in <FIG> can be obtained. The rotary cam shown in <FIG> has a pattern for opening a pump tube <NUM> at all angular positions. The rotary cam shown in <FIG> has a pattern for closing a pump tube <NUM> at the <NUM>° position and opening the pump tube <NUM> at the <NUM>°, <NUM>°, and <NUM>° positions, similar to the rotary cam 53c described above. The rotary cam shown in <FIG> has a pattern for closing a pump tube <NUM> at the <NUM>° position and the <NUM>° position and opening the pump tube <NUM> at the <NUM>° position and the <NUM>° position, similar to the rotary cams 53a and 53b described above. The rotary cam shown in <FIG> has a pattern for closing a pump tube <NUM> at the <NUM>° position and the <NUM>° position and opening the pump tube <NUM> at the <NUM>° position and the <NUM>° position. The rotary cam shown in <FIG> has a pattern for closing a pump tube <NUM> at the <NUM>°, <NUM>°, and <NUM>° positions and opening the pump tube <NUM> at the <NUM>° position. The rotary cam shown in <FIG> has a pattern for closing a pump tube <NUM> at all angular positions.

By combining rotary cams of the six patterns shown in <FIG>, combinations of open and closed states of the pump tubes 41a-41c required for various operations of the blood purification device <NUM> can be realized. With this arrangement, the blood purification device <NUM> can be operated in various operation patterns by driving the single motor <NUM> of the pump tube opening/closing mechanism <NUM>. Here, the assignment interval angle is not limited to <NUM>°, and may alternatively be <NUM>° or <NUM>°, for example. Further, although in the present embodiment a short side of the rotary cam corresponds to an open state and a long side corresponds to a closed state, it is alternatively possible to configure such that, conversely, a short side corresponds to a closed state and a long side corresponds to an open state.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG>. Parts equivalent to those of the blood purification device <NUM> described above by reference to <FIG> are labeled with the same reference signs, and repeated description thereof will be omitted.

As shown in <FIG>, in the blood purification device <NUM> of the present embodiment, a single rotary cam <NUM> that is rotated within a horizontal plane by a shaft <NUM> is used, instead of the three rotary cams 53a-53c of the blood purification device <NUM>, to thereby cause the finger casings 14a-14c to advance and retract with respect to the cover <NUM>. Further, projections 71a-71c that come into contact with the cam surfaces of the rotary cam <NUM> are provided respectively on the cam followers 54a-54c. The projections 71a-71c are connected to the finger casings 14a-41c via the cam followers 54a-54c and the posts 54p.

The rotary cam <NUM> includes: a first cam surface <NUM> that places the projections 71a-71c connected to the finger casings 14a-41c in the rear open position as shown in <FIG>; a second cam surface <NUM> that places the projections 71a-71c in the front closed position as shown in <FIG>; and a third cam surface <NUM> that places the projections 71a and 71b in the front closed position and places the projection 71c in the rear open position as shown in <FIG>. The first cam surface <NUM> is the <NUM>° position, the second cam surface <NUM> is the <NUM>° position, and the third cam surface <NUM> is the <NUM>° position. By rotating the shaft <NUM>, it is possible to set three states; namely: a state in which all of the pump tubes 41a-41c are opened; a state in which all of the pump tubes 41a-41c are closed; and a state in which the pump tubes 41a and 41b are closed and the pump tube 41c is opened.

The blood purification device <NUM> of the present embodiment achieves the same advantageous effects as the blood purification device <NUM> described above.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG>. Parts equivalent to those of the blood purification devices <NUM> and <NUM> described above by reference to <FIG> are labeled with the same reference signs, and repeated description thereof will be omitted. <FIG> depicts, in a sequential manner, respective states in which first to third cam surfaces <NUM>, <NUM>, and <NUM> of a plate cam <NUM> are located in a central part of the housing <NUM>. In the actual device, when the first cam surface <NUM> is inside the housing <NUM>, the second cam surface <NUM> and the third cam surface <NUM> are located outside the housing <NUM>. When the second cam surface <NUM> is inside the housing <NUM>, the first cam surface <NUM> and the third cam surface <NUM> are located outside the housing <NUM>. When the third cam surface <NUM> is inside the housing <NUM>, the first cam surface <NUM> and the second cam surface <NUM> are located outside the housing <NUM>.

The blood purification device <NUM> of the present embodiment is configured by replacing the rotary cam <NUM> of the blood purification device <NUM> described above by reference to <FIG> with the linearly-extending plate cam <NUM>. As shown in <FIG>, the plate cam <NUM> is moved to the left and the right by rotation of a drive gear <NUM> in engagement with a gear surface <NUM>.

As shown in <FIG>, the plate cam <NUM> comprises: the first cam surface <NUM> that places the projections 71a-71c in the rear open position; the second cam surface <NUM> that places the projections 71a-71c in the front closed position as shown in <FIG>; and the third cam surface <NUM> that places the projections 71a and 71b in the front closed position and places the projection 71c in the rear open position as shown in <FIG>. By rotating the drive gear <NUM> and thereby moving the plate cam <NUM> in the width direction, it is possible to set three states; namely: a state in which all of the pump tubes 41a-41c are opened; a state in which all of the pump tubes 41a-41c are closed; and a state in which the pump tubes 41a and 41b are closed and the pump tube 41c is opened.

The blood purification device <NUM> of the present embodiment achieves the same advantageous effects as the blood purification devices <NUM> and <NUM> described above.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG> and <FIG>. The blood purification device <NUM> of the present embodiment is configured such that a cassette <NUM> having a rear plate <NUM> is detachably mounted thereto, instead of the cover <NUM> of the blood purification device <NUM> described by reference to <FIG>. Parts equivalent to those of the blood purification device <NUM> described above by reference to <FIG> are labeled with the same reference signs, and repeated description thereof will be omitted.

As shown in <FIG>, the blood purification device <NUM> comprises the device main body <NUM>, and the cassette <NUM> that is detachably mounted to the device main body <NUM>. The cassette <NUM> is mounted to the device main body <NUM> by fitting its lower part into a cassette receiving seat <NUM> of the device main body <NUM>, and fastening a hook <NUM> provided on its upper part with a metal fixture <NUM> provided on the device main body <NUM>. When being used for dialysis, a blood circuit inlet 91a and a blood circuit outlet 91b of the cassette <NUM> are respectively connected to blood vessels of a human body so as to carry out dialysis. In the following description, the direction in which the device main body <NUM> and the cassette <NUM> are arranged will be referred to as the front-rear direction, the direction orthogonal to the front-rear direction in a horizontal plane will be referred to as the width direction, and the upright direction will be referred to as the vertical direction.

As shown in <FIG>, a casing <NUM> of the cassette <NUM> houses therein the dialyzer <NUM>, the dialysate regeneration column <NUM>, and the water removal container <NUM>. The plurality of elastic pump tubes <NUM> (41a-41c) are mounted on a surface 32a of the rear plate <NUM>, which is a flat plate of the casing <NUM> that is located facing the device main body <NUM>. Accordingly, similar to the cover <NUM> described above, the rear plate <NUM> of the cassette <NUM> of the present embodiment constitutes a tube receiving plate that holds the pump tubes <NUM> (41a-41c). The device main body <NUM> includes the housing <NUM>, finger driving units <NUM> received inside the housing <NUM>, the pump tube opening/closing mechanism <NUM>, and the control unit <NUM>. The finger driving units <NUM>, the pump tube opening/closing mechanism <NUM>, and the control unit <NUM> are identical to those of the blood purification device <NUM> described above.

The base <NUM> of the housing <NUM> extends forward, and the cassette receiving seat <NUM> is mounted to the extended portion. The cassette receiving seat <NUM> is formed by providing a flange 96b, into which the cassette <NUM> is to be fitted, in an upright manner in a cornered C-shape on a peripheral portion of a bottom plate 96a. When the cassette <NUM> is fitted into the cassette receiving seat <NUM>, a bottom plate <NUM> of the cassette <NUM> is supported by the bottom plate 96a of the cassette receiving seat <NUM>, and a lower part of the casing <NUM> of the cassette <NUM> fits on the inner side of the flange 96b of the cassette receiving seat <NUM>. When the cassette <NUM> is mounted to the device main body <NUM> and the surface 32a of the rear plate <NUM> of the cassette <NUM> located toward the device main body <NUM> is in contact with the front surface of the front plate 13c of the device main body <NUM>, the pump tubes <NUM> (41a-41c) are received in the vertically-extending V-shaped tube receiving grooves <NUM> (24a-24c) provided on the front surfaces of the finger casings <NUM> (14a-14c), in the same manner as described above by reference to <FIG> and <FIG>. The finger driving units 20a-20c and the pump tubes 41a-41c constitute the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI, respectively.

Operation of the blood purification device <NUM> of the present embodiment is identical to that of the blood purification device <NUM> described above. In the blood purification device <NUM> of the present embodiment, the dialyzer <NUM>, the water removal container <NUM>, the dialysate regeneration column <NUM>, the pump tubes 41a-41c, and connection tubes connecting between the respective components, all of which constitute the blood circuit <NUM> and the dialysate circuit <NUM>, are housed in the cassette <NUM> as a single unit, and this unit can be mounted to and detached from the device main body <NUM>. Accordingly, in addition to the advantageous effects achieved by the blood purification device <NUM>, the blood purification device <NUM> of the present embodiment also achieves the advantageous effects that the cassette <NUM> integrating the liquid-contacting section can be used in a disposable manner and that the handling of the blood purification device <NUM> can thereby be simplified.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG>. The blood purification device <NUM> of the present embodiment is such that, in addition to the cam followers 54a-54c arranged toward the front of the rotary cams 53a-53c, cam followers 54d-54f are provided toward the rear, and the cam followers 54a-54c are respectively formed into single units with the cam followers 54d-54f by being connected by connecting members <NUM>. The configurations of the rotary cams 53a-53c and the cam followers 54a-54c are identical to those of the blood purification device <NUM> described above by reference to <FIG>. Here, the blood purification device <NUM> does not include the coil springs <NUM>. The rotary cams 53a-53c, the cam followers 54a-54c and 54d-54f, and the connecting members <NUM> constitute the retraction mechanism.

As shown in <FIG>, when the shaft <NUM> is rotated by <NUM>° from the initial position, the rotary cams 53a-53c push the front cam followers 54a-54c forward into the front closed position. As a result, the finger casings 14a-14c are moved forward, and the fingers 15a-15c press the pump tubes 41a-41c against the cover <NUM>, so that the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI are placed in a state capable of delivering liquid.

As shown in <FIG>, when the shaft <NUM> is rotated by <NUM>° from the state shown in <FIG>, the rotary cams 53a-53c push the rear cam followers 54d-54f rearward into the rear open position. As a result, the finger casings 14a-14c are moved rearward by distance L, and the fingers 15a-15c of the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI are placed in a state of being away from the respective pump tubes 41a-41c.

In this way, in the blood purification device <NUM> of the present embodiment, the finger casings 14a-14b are moved in the front-rear direction by engaging the two front and rear cam followers 54a-54c and 54d-54f with the respective rotary cams 53a-53b, without using the coil springs <NUM>. The blood purification device <NUM> of the present embodiment achieves the same advantageous effects as the blood purification device <NUM> described above.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG>. The blood purification device <NUM> of the present embodiment is configured by providing a flat-shaped tube receiving plate <NUM> between the cover <NUM> and the pump tubes <NUM> (41a-41c). By rotating rotary cams 53d attached to the shaft <NUM>, the tube receiving plate <NUM> is caused to advance toward the finger driving units <NUM> (20a-20c). Further, the tube receiving plate <NUM> is pulled back toward the cover <NUM> by coil springs <NUM> so as to be retracted from the finger driving units <NUM> (20a-20c). In the blood purification device <NUM>, the finger driving units <NUM> (20a-20c) are fixed to the device main body <NUM>, and do not move in the front-rear direction.

As shown in <FIG>, the tube receiving plate <NUM> is a flat-shaped member disposed between the cover <NUM> and the pump tubes <NUM> (41a-41c), and has sufficient hardness for collapsing the pump tubes <NUM> (41a-41c) in cooperation with the fingers 15a-15c. The vertical length of the tube receiving plate <NUM> is the same as the vertical length of the fingers 15a-15c. The tube receiving plate <NUM> is held on the cover <NUM> together with the pump tubes <NUM> (41a-41c).

At both ends, in the width direction, of the tube receiving plate <NUM>, flanges <NUM> are provided extending rearward. At the rear ends of the flanges <NUM>, connection mechanisms <NUM> are attached, which, when the cover <NUM> is closed, engage with cam arms <NUM> mounted to the housing <NUM>. A rib <NUM> protrudes from a side surface of each flange <NUM>, and the coil spring <NUM> is attached between the rib <NUM> and the cover <NUM>.

On the rear plate 11a of the device main body <NUM>, the brackets <NUM> are attached, which rotatably support the shaft <NUM>. The rotary cams 53d are attached to the two ends of the shaft <NUM>. Further, toward both sides in the interior of the housing <NUM>, the cam arms <NUM> supported to be slidable in the front-rear direction are mounted. At the rear ends of the cam arms <NUM>, cam followers <NUM> that engage the rotary cams 53d are attached. Each rotary cam 53d has at least one protruded part, and may have, for example, the same shape as the rotary cam 53a or the rotary cam 53c shown in <FIG>.

When the cover <NUM> is closed, the flanges <NUM> of the tube receiving plate <NUM> and the cam arms <NUM> are connected by the connection mechanisms <NUM>. When the shaft <NUM> is rotated by the motor <NUM> (not shown), the protruded parts of the rotary cams 53d engage the cam followers <NUM> and move the cam followers <NUM> rearward. As a result, the tube receiving plate <NUM> is moved rearward, and the pump tubes 41a-41c are pressed by the fingers 15a-15c, so that the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI are placed in a state capable of delivering liquid.

When the shaft <NUM> is rotated by the motor <NUM> and the protruded parts of the rotary cams 53d are disengaged from the cam followers <NUM>, the tube receiving plate <NUM> is pulled back toward the cover <NUM> by the coil springs <NUM>, so that the fingers 15a-15c of the dialysate outlet pump DPO, the blood pump BP, and the dialysate inlet pump DPI are placed in a state of being away from the pump tubes 41a-41c.

Although it has been explained that the tube pressing members are the fingers <NUM> (15a-15c) in the blood purification devices <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> of the above-described embodiments, the tube pressing members are not limited thereto, and may alternatively be rollers that squeeze the pump tubes <NUM> (41a-41c). When such rollers are used, the surface 30a of the cover <NUM> located toward the device main body <NUM> and the surface of the tube receiving plate <NUM> located toward the device main body <NUM> are configured as a curved surface that conforms to the shape of the outer surface of the rollers.

As shown in <FIG> and <FIG>, the blood purification device <NUM> is configured by attaching the cam followers 54a-54c to the finger casings <NUM> (14a-14c) of the finger driving units <NUM> (20a-20c) via adjustment springs <NUM>, which are elastic members. Other structures are identical to those of the blood purification device <NUM> described above by reference to <FIG>.

As shown in <FIG>, a post 54p is fixed to a front part of the cam follower 54a, and a recess <NUM> into which the tip of the post 54p is inserted is formed in the back plate <NUM> of the finger casing 14a. Further, a washer 54q having an inner diameter substantially equal to the diameter of the post 54p is fixed to the peripheral edge of the recess <NUM> in the back plate <NUM>. An adjustment spring <NUM> is mounted to the outer periphery of the post 54p between the washer 54q and the cam follower 54a. Although the adjustment spring <NUM> is a coil spring in the blood purification device <NUM>, the adjustment spring <NUM> is not limited thereto, and may alternatively be a leaf spring or may comprise a rubber member. The washer 54q may alternatively be not provided.

The rotary cam 53a is rotated so as to cause the cam follower 54a to advance toward the finger driving unit 20a. When the adjustment spring <NUM> is thereby contracted, the tip of the post 54p enters into the recess <NUM> in the back plate <NUM>.

The spring constant of the adjustment spring <NUM> is greater than the spring constant in the direction in which the pump tubes <NUM> (41a-41c) are collapsed, is equal to or greater than a spring constant at which the pump tubes <NUM> (41a-41c) can be completely closed by the reaction force, and is such that, even when the spring <NUM> is compressed, the reaction force does not damage the pump tubes <NUM> (41a-41c).

A closing operation for closing the pump tube 41a by rotating the rotary cam 53a of the blood purification device <NUM> and thereby causing the finger driving unit 20a to advance toward the cover <NUM> will be described by reference to <FIG> are schematic diagrams for explaining the closing operation, and elements shown therein are depicted in a simplified manner. The operation of the finger driving units 20b and 20c is identical to the operation of the finger driving unit 20a.

As shown in <FIG>, in the initial state, the adjustment spring <NUM> has a reference length L1, and the outer shape of the pump tube 41a has a size d1.

As shown in <FIG>, when the rotary cam 53a is rotated, the cam follower 54a advances toward the cover <NUM>. As explained above, the spring constant of the adjustment spring <NUM> is greater than the spring constant in the direction in which the pump tube 41a is collapsed. Accordingly, when the cam follower 54a advances toward the cover <NUM>, the pump tube 41a becomes collapsed by being squeezed between the finger 15a and the cover <NUM>. When the rotary cam 53a has rotated and the pump tube 41a is collapsed and placed in the closed state, the pump tube 41a has a thickness d2. At that point, the cam follower 54a has advanced by (d1-d2) + (L1-L2), and the adjustment spring <NUM> has a length L2 that is slightly reduced from the reference length L1.

Next, as shown in <FIG>, when the rotary cam 53a is rotated further and the cam follower 54a advances further toward the cover <NUM>, the adjustment spring <NUM> starts to contract from the length L2 while the thickness of the pump tube 41a remains d2. At that time, the tip of the post 54p advances into the recess <NUM> in the back plate <NUM> shown in <FIG>. Subsequently, when the rotary cam 53a is rotated further and the cam follower 54a advances by (d1-d2) + (L1-L3), the adjustment spring <NUM> contracts to a length L3. At that point, there is a gap between the finger driving unit 20a and the surface 30a of the cover <NUM>. The reaction force of the adjustment spring <NUM> at that time is of a magnitude that does not damage the pump tube 41a.

In this way, in the blood purification device <NUM>, after the finger 15a has closed the pump tube 41a, the adjustment spring <NUM> contracts by a length (L2-L3) and thereby absorbs an advancing distance of the cam follower 54a. For this reason, closing and opening of the pump tube 41a can be carried out reliably without adjustment of the advancing distance of the finger driving unit 20a with respect to the cover <NUM> with high accuracy. In addition, since the reaction force of the adjustment spring <NUM> upon contracting to the length L3 is of a magnitude that does not damage the pump tube 41a, excessive pressing of the pump tube 41a can be avoided, and damages to the pump tube 41a can be suppressed.

Although it is explained above that the recess <NUM> into which the tip of the post 54p is inserted is provided in the back plate <NUM> of the finger casing 14a, the recess <NUM> may be not provided so long as the structure is such that the tip of the post 54p does not interfere with the back plate <NUM> when the adjustment spring <NUM> is in the contracted state. For example, it may be configured such that the thickness of the washer 54q is greater than the extent of contraction of the adjustment spring <NUM>, so that the tip of the post 54p advances into the washer 54q when the adjustment spring <NUM> contracts. Further, the portion of the back plate <NUM> abutted by the adjustment spring <NUM> may be formed in a protruded shape.

Next, a blood purification device <NUM>, which is a variant of the blood purification device <NUM>, will be described by reference to <FIG>. As shown in <FIG>, the blood purification device <NUM> is configured such that, in a state where the finger 15a has moved to the frontmost position, the front end of the finger 15a is located rearward by a distance d2 from the front end 25a of the finger driving unit 20a. The configuration of the finger driving units 20b and 20c is the same as that of the finger driving unit 20a. Other structures are identical to those of the blood purification device <NUM> described above with reference to <FIG>.

According to this configuration, as shown in <FIG>, when the finger 15a closes the pump tube 41a and the thickness of the pump tube 41a becomes d2, the front end 25a of the finger driving unit 20a abuts the surface 30a of the cover <NUM>, and the finger 15a does not press the pump tube 41a any further. With this arrangement, it is possible to prevent application of an excessive pressing force to the pump tube 41a, and damages to the pump tube 41a can be more effectively suppressed.

Next, a blood purification device <NUM>, which is a variant of the blood purification device <NUM>, will be described by reference to <FIG>. As shown in <FIG>, in the blood purification device <NUM>, the post 54p is fixed to the back plate <NUM> of the finger casing 14a, and the cam follower 54a has formed therein a through hole 54Ha which is penetrated by the post 54p. The adjustment spring <NUM> is mounted around the post 54p between the back plate <NUM> and the cam follower 54a. When the rotary cam <NUM> pushes the cam follower 54a forward and the adjustment spring <NUM> contracts, the rear end of the post 54p advances rearward through the through hole 54Ha in the cam follower 54a. The configurations of the back plates <NUM> of the finger casings 14b and 14c, the cam followers 54b and 54c, and the posts 54p are the same as those described above.

The blood purification device <NUM> is identical in operation to that of the blood purification device <NUM> described above, and achieves the same advantageous effects.

As shown in <FIG> and <FIG>, in the blood purification device <NUM>, recesses 30Aa-30Ac are formed at portions of the cover <NUM> facing the fingers 15a-15c of the finger driving units 20a-20c, and inside the recesses 30Aa-30Ac, tube support plates 30Ba-30Bc, which are the tube receiving plates, are mounted via adjustment springs 30Sa-30Sc. The pump tube opening/closing mechanism <NUM> causes the rotary cams 53a-53c to rotate and thereby causes the finger driving units 20a-20c to advance and retract with respect to the tube support plates 30Ba-30Bc, so as to carry out closing and opening of the pump tubes 41a-41c respectively disposed between the fingers 15a-15c of the finger driving units 20a-20c and the tube support plates 30Ba-30Bc. Other structures are identical to those of the blood purification device <NUM> described above by reference to <FIG>. So long as the tube support plates 30Ba-30Bc are attached to the cover <NUM> via the adjustment springs 30Sa-30Sc, it is possible that the configuration includes no recesses 30Aa-30Ac. Further, the portions of the cover <NUM> abutted by the adjustment springs 30Sa-30Sc may be formed in a protruded shape.

As with the blood purification device <NUM> described above, the spring constants of the adjustment springs 30Sa-30Sc are greater than the spring constant in the direction in which the pump tubes <NUM> (41a-41c) are collapsed, are equal to or greater than a spring constant at which the pump tubes <NUM> (41a-41c) can be completely closed by the reaction force, and are such that, even when the adjustment springs 30Sa-30Sc are compressed, the reaction force does not damage the pump tubes <NUM> (41a-41c).

As shown in <FIG>, in the initial state, the adjustment spring 30Sa has a reference length L4, and the outer shape of the pump tube 41a has a size d1.

As shown in <FIG>, when the rotary cam 53a is rotated, the cam follower 54a advances toward the cover <NUM>. As described above, the spring constant of the adjustment spring 30Sa is greater than the spring constant in the direction of squeezing the pump tube 41a. Accordingly, when the cam follower 54a advances toward the cover <NUM>, the pump tube 41a becomes collapsed by being squeezed between the finger 15a and the tube support plate 30Ba. When the rotary cam 53a has rotated and the pump tube 41a is collapsed and placed in the closed state, the pump tube 41a has a thickness d2. At that point, the cam follower 54a has advanced by (d1-d2) + (L4-L5), and the adjustment spring 30Sa has a length L5 that is slightly reduced from the reference length L4.

Next, as shown in <FIG>, when the rotary cam 53a is rotated further and the cam follower 54a advances further toward the cover <NUM>, the adjustment spring 30Sa starts to contract from the length L4 while the thickness of the pump tube 41a remains d2. At that time, the tube support plate 30Ba enters into the recess 30Aa in the cover <NUM>. Subsequently, when the rotary cam 53a is rotated further and the cam follower 54a advances by (d1-d2) + (L4-L6), the adjustment spring 30Sa contracts to a length L6. At that point, there is a gap between the finger driving unit 20a and the surface 30Ca of the tube support plate 30Ba. The reaction force of the adjustment spring 30Sa at that time is of a magnitude that does not damage the pump tube 41a.

In this way, in the blood purification device <NUM>, after the pump tube 41a is closed, the adjustment spring 30Sa contracts by a length (L5-L6) and thereby absorbs an advancing distance of the cam follower 54a. For this reason, closing and opening of the pump tube 41a can be carried out reliably without adjustment of the advancing distance of the finger driving unit 20a with respect to the cover <NUM> with high accuracy. In addition, since the reaction force of the adjustment spring 30Sa upon contracting to the length L6 is of a magnitude that does not damage the pump tube 41a, excessive pressing of the pump tube 41a can be avoided, and damages to the pump tube 41a can be suppressed. Although the adjustment spring 30Sa is a coil spring in the blood purification device <NUM>, the adjustment spring 30Sa is not limited thereto, and may alternatively be a leaf spring or may comprise a rubber member.

According to this configuration, as shown in <FIG>, when the finger 15a closes the pump tube 41a and the thickness of the pump tube 41a becomes d2, the front end 25a of the finger driving unit 20a abuts the surface 30Ca of the tube support plate 30Ba, and the finger 15a does not press the pump tube 41a any further. Here, the spring constant of the adjustment spring 30Sa is adjusted such that, at that point, a gap e is present between the front end 25a of the finger driving unit 20a and the surface 30a of the cover <NUM>. With this arrangement, it is possible to prevent application of an excessive pressing force to the pump tube 41a, and damages to the pump tube 41a can be more effectively suppressed.

Although it has been described that the adjustment springs <NUM> are respectively provided between the finger driving units 20a-20c and the cam followers 54a-54c in the blood purification devices <NUM> and <NUM>, and that the adjustment springs 30Sa-30Sc are provided between the finger driving units 20a-20c and the cover <NUM> in the blood purification devices <NUM> and <NUM>, embodiments are not limited thereto. For example, an embodiment may be configured such that the adjustment springs <NUM> are respectively provided between the finger driving units 20a-20c and the cam followers 54a-54c, and in addition, the adjustment springs 30Sa-30Sc are provided between the finger driving units 20a-20c and the cover <NUM>. Further, an embodiment may be configured such that, for a part of the finger driving units 20a-20c, the adjustment springs <NUM> are respectively disposed between those finger driving units and the cam followers 54a-54c, and for another part of the finger driving units 20a-20c, the adjustment springs 30Sa are disposed between those finger driving units and the cover <NUM>.

Next, a blood purification device <NUM> according to another embodiment will be described by reference to <FIG> and <FIG>. In the blood purification device <NUM>, tips of the cam arms <NUM> are each formed in an L-shape to thereby provide tip portions 143A that face the rotary cams 53d. Respectively between the tip portions 143A and the rotary cams 53d, cam followers <NUM> are arranged via adjustment springs <NUM>, which are elastic members. Further, adjustment springs <NUM> are provided between the cam arms <NUM> and the connection mechanisms <NUM>. Other structures are identical to those of the blood purification device <NUM> described by reference to <FIG>.

As shown in <FIG>, a post 154p is fixed to a rear part of each cam follower <NUM>, and a recess 143B into which the tip of the post 154p is inserted is formed in the tip portion 143A. Further, a washer 154q having an inner diameter substantially equal to the diameter of the post 154p is fixed to the peripheral edge of the recess 143B in the tip portion 143A. The adjustment spring <NUM> is mounted to the outer periphery of the post 154p between the washer 154q and the cam follower <NUM>. Although the adjustment spring <NUM> is a coil spring in the blood purification device <NUM>, the adjustment spring <NUM> is not limited thereto, and may alternatively be a leaf spring or may comprise a rubber member.

The rotary cam 53a is rotated so as to cause the cam follower 154a to advance toward the tip portion 143A. When the adjustment spring <NUM> is thereby contracted, the tip of the post 154p advances into the recess 143B in the tip portion 143A.

Similar to the blood purification devices <NUM> and <NUM> described above by reference to <FIG>, in the blood purification device <NUM>, the adjustment springs <NUM> and <NUM> contract and thereby absorb an advancing distance of the cam followers <NUM>. Accordingly, closing and opening of the pump tubes 41a-41c can be carried out reliably without adjustment of the advancing distance of the cam arms <NUM> with high accuracy, and at the same time, damages to the pump tube 41a-41c can be suppressed.

Although it is explained that, in the blood purification device <NUM> described above, the adjustment springs <NUM> and <NUM> are respectively provided between the tip portions 143A of the cam arms <NUM> and the rotary cams 53d and between the cam arms <NUM> and the connection mechanisms <NUM>, embodiments are not limited thereto. An embodiment may be configured such that the adjustment springs are provided at only either one of the above-noted sites. Further, similar to the blood purification device <NUM> described above by reference to <FIG>, it may be configured such that the posts 154p are attached to the tip portions 143A without providing the recesses 143B, and through holes to be penetrated by the posts 154p are formed in the cam followers <NUM>.

Claim 1:
A blood purification device (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), comprising:
a tube receiving plate (<NUM>) that holds an elastic pump tube (<NUM>, 41a-41c);
a tube pressing member driving unit (<NUM>, 20a-20c) which is positioned facing the tube receiving plate (<NUM>) across the pump tube (<NUM>, 41a-41c), and which causes a tube pressing member (<NUM>, 15a-15c) to be moved with respect to the tube receiving plate (<NUM>); and
a pump tube opening/closing mechanism (<NUM>) that causes the tube pressing member driving unit (<NUM>, 20a-20c) to advance and retract with respect to the tube receiving plate (<NUM>), and thereby carries out closing and opening of the pump tube (<NUM>, 41a-41c) which is positioned between the tube pressing member (<NUM>, 15a-15c) and the tube receiving plate (<NUM>).