U.S. patent application number 14/966239 was filed with the patent office on 2016-04-07 for reciprocating pump.
The applicant listed for this patent is Nikkiso Company Limited. Invention is credited to Yuya Menjoh, Hiroaki Suzuki, Satoaki Yamada.
Application Number | 20160097384 14/966239 |
Document ID | / |
Family ID | 51904353 |
Filed Date | 2016-04-07 |
United States Patent
Application |
20160097384 |
Kind Code |
A1 |
Menjoh; Yuya ; et
al. |
April 7, 2016 |
RECIPROCATING PUMP
Abstract
A reciprocating pump includes a pump chamber; a suction port
which enables a liquid to be suctioned into the pump chamber; a
discharge port which enable a liquid in the pump chamber to be
discharged; a plunger which is capable of reciprocating in the pump
chamber by a motor; check valves are disposed between the pump
chamber and a flow route on the suction port side and a flow route
on the discharge port side, are openable and closable in response
to a change in a liquid pressure in the pump chamber, which is
produced due to the reciprocating of the plunger, a detection
device that is able to detect a period of time during which the
check valve is in an opened state or in a closed state in a
predetermined cycle; and an arithmetic device that performs an
arithmetic operation to obtain pump volumetric efficiency or a flow
rate based on a comparison between a period of detection time
detected by the detection device and a period of time during which
the check valve is in the opened state or in the closed state in
the predetermined cycle during normal operation.
Inventors: |
Menjoh; Yuya; (Shizuoka,
JP) ; Yamada; Satoaki; (Shizuoka, JP) ;
Suzuki; Hiroaki; (Shizuoka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nikkiso Company Limited |
Tokyo |
|
JP |
|
|
Family ID: |
51904353 |
Appl. No.: |
14/966239 |
Filed: |
December 11, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2014/066436 |
Jun 20, 2014 |
|
|
|
14966239 |
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Current U.S.
Class: |
417/443 |
Current CPC
Class: |
A61M 1/1635 20140204;
F04B 19/22 20130101; F04B 49/22 20130101; F04B 17/00 20130101; F04B
53/16 20130101; F04B 53/1047 20130101; F04B 51/00 20130101; F04B
53/14 20130101; A61M 1/14 20130101; F04B 53/1057 20130101; F04B
9/042 20130101; F04B 49/06 20130101; F04B 49/10 20130101; F04B
53/10 20130101 |
International
Class: |
F04B 51/00 20060101
F04B051/00; F04B 53/16 20060101 F04B053/16; F04B 53/10 20060101
F04B053/10; F04B 53/14 20060101 F04B053/14; F04B 19/22 20060101
F04B019/22; F04B 17/00 20060101 F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 2013 |
JP |
2013-130912 |
Claims
1. A reciprocating pump comprising: a pump chamber which is able to
flow a liquid; a suction port which enables a liquid to be
suctioned into the pump chamber; a discharge port which enable a
liquid in the pump chamber to be discharged; a reciprocating device
which is capable of reciprocating in the pump chamber by a drive
device and enables a liquid to be suctioned into the pump chamber
from the suction port and enables the liquid to be discharged from
the discharge port due to the reciprocating; valve devices which
are disposed between the pump chamber and a flow route on the
suction port side and a flow route on the discharge port side, are
openable and closable in response to a change in a liquid pressure
in the pump chamber, which is produced depending on the
reciprocating of the reciprocating device, allow a liquid to flow
in an opened state, and block a liquid from flowing in a closed
state; a detection device that is able to detect a period of time
during which the valve device is in the opened state or in the
closed state in a predetermined cycle; and an arithmetic device
that performs an arithmetic operation to obtain pump volumetric
efficiency or a flow rate based on a comparison between a period of
detection time detected by the detection device and a period of
time during which the valve device is in the opened state or in the
closed state in the predetermined cycle during normal
operation.
2. The reciprocating pump according to claim 1, wherein the
detection device detects a period of time during which both the
valve device on the suction port side and the valve device on the
discharge port side are in the closed state in the predetermined
cycle and the arithmetic device performs an arithmetic operation to
obtain pump volumetric efficiency or a flow rate based on a
comparison between the period of detection time detected by the
detection device and a period of time during which both the valve
device on the suction port side and the valve device on the
discharge port side are in the closed state in the predetermined
cycle during normal operation.
3. The reciprocating pump according to claim 1, wherein the
detection device detects a period of time during which the valve
device on the discharge side is in the opened state in the
predetermined cycle and the arithmetic device performs an
arithmetic operation to obtain pump volumetric efficiency or a flow
rate based on a comparison between the period of detection time
detected by the detection device and a period of time during which
the valve device on the discharge side is in the opened state in
the predetermined cycle during normal operation.
4. The reciprocating pump according to claim 1, wherein the liquid
contains a conductive liquid and the detection device includes a
transmitting electrode unit and a receiving electrode unit which
are disposed on the pump chamber and on the flow route on the
suction port side or on the flow route on the discharge port side,
respectively, which are positioned to interpose the valve device
therebetween and a calculating device that is able to calculate a
detection period of time during which the valve device is in the
opened state or in the closed state based on a period of current
application time between the transmitting electrode unit and the
receiving electrode unit.
5. The reciprocating pump according to claim 4, further comprising:
a shutout determination device that is able to determine whether or
not the valve device is in a good shutout state and to monitor the
shutout state based on the current application between the
transmitting electrode unit and the receiving electrode unit.
6. The reciprocating pump according to claim 1, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
7. The reciprocating pump according to claim 6, wherein dialysate
that is guided to a blood purification device flows in the liquid
supply-side pump chamber, dialysate guided out from the blood
purification device flows in the liquid drainage-side pump chamber,
and the reciprocating of the reciprocating device enables dialysate
to be supplied to the blood purification device and to be guided
out from the blood purification device.
8. The reciprocating pump according to claim 6, wherein the
arithmetic device obtains pump volumetric efficiency or a flow rate
in the liquid supply-side pump chamber and in the liquid
drainage-side pump chamber and is able to detect liquid leakage
between the liquid supply-side discharge port and the liquid
drainage-side suction port based on a comparison between pump
volumetric efficiency or a flow rate in the liquid supply-side pump
chamber and the pump volumetric efficiency or the flow rate in the
liquid drainage-side pump chamber.
9. The reciprocating pump according to claim 2, wherein the liquid
contains a conductive liquid and the detection device includes a
transmitting electrode unit and a receiving electrode unit which
are disposed on the pump chamber and on the flow route on the
suction port side or on the flow route on the discharge port side,
respectively, which are positioned to interpose the valve device
therebetween and a calculating device that is able to calculate a
detection period of time during which the valve device is in the
opened state or in the closed state based on a period of current
application time between the transmitting electrode unit and the
receiving electrode unit.
10. The reciprocating pump according to claim 3, wherein the liquid
contains a conductive liquid and the detection device includes a
transmitting electrode unit and a receiving electrode unit which
are disposed on the pump chamber and on the flow route on the
suction port side or on the flow route on the discharge port side,
respectively, which are positioned to interpose the valve device
therebetween and a calculating device that is able to calculate a
detection period of time during which the valve device is in the
opened state or in the closed state based on a period of current
application time between the transmitting electrode unit and the
receiving electrode unit.
11. The reciprocating pump according to claim 2, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
12. The reciprocating pump according to claim 3, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
13. The reciprocating pump according to claim 4, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
14. The reciprocating pump according to claim 5, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
15. The reciprocating pump according to claim 9, wherein the pump
chamber is adapted to have a liquid supply-side pump chamber that
communicates with a liquid supply-side suction port and a liquid
supply-side discharge port and a liquid drainage-side pump chamber
that communicates with a liquid drainage-side suction port and a
liquid drainage-side discharge port, and has a configuration in
which the valve device is provided for each of the liquid
supply-side suction port, the liquid supply-side discharge port,
the liquid drainage-side suction port, and the liquid drainage-side
discharge port, the reciprocating device reciprocates in both the
liquid supply-side pump chamber and the liquid drainage-side pump
chamber, and thereby, liquids in the liquid supply-side pump
chamber and the liquid drainage-side pump chamber are discharged
from the liquid supply-side discharge port and the liquid
drainage-side discharge port, respectively.
16. The reciprocating pump according to claim 7, wherein the
arithmetic device obtains pump volumetric efficiency or a flow rate
in the liquid supply-side pump chamber and in the liquid
drainage-side pump chamber and is able to detect liquid leakage
between the liquid supply-side discharge port and the liquid
drainage-side suction port based on a comparison between pump
volumetric efficiency or a flow rate in the liquid supply-side pump
chamber and the pump volumetric efficiency or the flow rate in the
liquid drainage-side pump chamber.
Description
FIELD
[0001] The present invention relates to a reciprocating pump that
includes a reciprocating device which is able to reciprocate in a
pump chamber by a drive device, performs suction of a liquid from a
suction port into the pump chamber due to the reciprocating, and
enables the liquid to be discharged from a discharge port.
BACKGROUND
[0002] In a blood purification device such as a dialyzer which is
used during hemodialysis treatment, a dialysate supplying line for
supplying dialysate is connected with a dialysate discharging line
for discharging dialysis effluent. The dialysate supplying line and
the dialysate discharging line are configured to extend from a
dialysis device such that the lines are connected with a blood
purification device and to supply dialysate to the blood
purification device and to discharge dialysate (dialysis effluent)
from the blood purification device.
[0003] In the dialysis device, a reciprocating pump (duplex pump)
is disposed between the dialysate supplying line and the dialysate
discharging line to connect both lines. For example, as disclosed
in PTL 1, the reciprocating pump includes a housing in which a
plunger is accommodated in a reciprocating manner, a liquid
supply-side pump chamber and a liquid drainage-side pump chamber
which are formed in the housing and are separated due to the
plunger, and a motor for reciprocating the plunger.
[0004] In addition, in the configuration, valve devices such as a
check valve are provided on a suction port side and on a discharge
port side, respectively, in the liquid supply-side pump chamber and
the liquid drainage-side pump chamber. When the motor is driven
such that the plunger is caused to reciprocate, the dialysate is
discharged from the liquid supply-side pump chamber and is supplied
to the blood purification device and the dialysate (dialysis
effluent) from the blood purification device can be suctioned to
the liquid drainage-side pump chamber and can be discharged to the
outside.
[0005] Incidentally, as disclosed in PTL 2, for example, a
reciprocating pump is proposed, in which, in order to monitor
shutout states (liquid-tight degrees of closed states) of the valve
device on the suction port side and the valve device on the
discharge port side, a transmitting electrode unit is formed in the
pump chamber and a receiving electrode unit is formed in each of
the valve device on the suction port side and the valve device on
the discharge port side such that current is applied between the
transmitting electrode unit and the receiving electrode units.
According to the reciprocating pump, current application between
the transmitting electrode unit and the receiving electrode units
is detected and thereby, it is possible to monitor the shutout
states (liquid-tight degrees of closed states) of the valve device
on the suction port side and the valve device on the discharge port
side. Examples of some instruments may be found in: PTL 1: Japanese
Unexamined Patent Application Publication No. 2003-284772 and PTL
2: Japanese Unexamined Patent Application Publication No. 7-174659
both of which are expressly incorporated by reference herein for
all purposes.
SUMMARY
[0006] However, in the related art disclosed in PTL 1, there is a
concern that the plunger will not be shifted to a set end point of
reciprocating, for example, due to the wear of a component (wear of
a bearing, sealing substance, or the like) of the pump such that it
is not possible to achieve set pump volumetric efficiency or a set
flow rate. That is, in a case where the plunger is not shifted to
the set end point of reciprocating, the valve device is likely to
enter into a closed state at an earlier timing than that during
normal operation such that the amount of dialysate which is
discharged is reduced by an amount in response to a changed state.
Therefore, since the amount of dialysate which is supplied to the
blood purification device is reduced, there is a problem in that
blood purification efficiency (treatment efficiency) is
lowered.
[0007] In order to solve the problem, it is considered that the
related art disclosed in PTL 2 is used; however, in the related
art, it is possible to monitor the shutout states (liquid-tight
degrees of closed states) of the valve device on the suction port
side and the valve device on the discharge port side but it is not
possible to monitor whether or not set pump volumetric efficiency
or a set flow rate is achieved. Such a problem is not limited to
the duplex pump which supplies dialysate, but can also arise in a
reciprocating pump in general which causes a liquid to be suctioned
and discharging through the pump chambers by the reciprocating of a
plunger (reciprocating device).
[0008] The present teachings are made taking such problems into
account and an object thereof is to provide a reciprocating pump
which is able to monitor pump volumetric efficiency or a flow rate
with ease and accuracy.
[0009] The teachings herein provide a reciprocating pump including:
a pump chamber which is able to flow a liquid; a suction port which
enables a liquid to be suctioned into the pump chamber; a discharge
port which enable a liquid in the pump chamber to be discharged; a
reciprocating device which is capable of reciprocating in the pump
chamber by a drive device and enables a liquid to be suctioned into
the pump chamber from the suction port and enables the liquid to be
discharged from the discharge port due to the reciprocating; valve
devices which are disposed between the pump chamber and a flow
route on the suction port side and a flow route on the discharge
port side, are openable and closable in response to a change in a
liquid pressure in the pump chamber, which is produced depending on
the reciprocating of the reciprocating device, allow a liquid to
flow in an opened state, and block a liquid from flowing in a
closed state; a detection device that is able to detect a period of
time during which the valve device is in the opened state or in the
closed state in a predetermined cycle; and an arithmetic device
that performs an arithmetic operation to obtain pump volumetric
efficiency or a flow rate based on a comparison between a period of
detection time detected by the detection device and a period of
time during which the valve device is in the opened state or in the
closed state in the predetermined cycle during normal
operation.
[0010] The teachings herein provide the reciprocating pump taught
herein, in which the detection device detects a period of time
during which both the valve device on the suction port side and the
valve device on the discharge port side are in the closed state in
the predetermined cycle and the arithmetic device performs an
arithmetic operation to obtain pump volumetric efficiency or a flow
rate based on a comparison between the period of detection time
detected by the detection device and a period of time during which
both the valve device on the suction port side and the valve device
on the discharge port side are in the closed state in the
predetermined cycle during normal operation.
[0011] The teachings herein provide the reciprocating pump taught
herein, in which the detection device detects a period of time
during which the valve device on the discharge side is in the
opened state in the predetermined cycle and the arithmetic device
performs an arithmetic operation to obtain pump volumetric
efficiency or a flow rate based on a comparison between the period
of detection time detected by the detection device and a period of
time during which the valve device on the discharge side is in the
opened state in the predetermined cycle during normal
operation.
[0012] The teachings herein provide the reciprocating pump taught
herein, in which the liquid contains a conductive liquid and the
detection device includes a transmitting electrode unit and a
receiving electrode unit which are disposed on the pump chamber and
on the flow route on the suction port side or on the flow route on
the discharge port side, respectively, which are positioned to
interpose the valve device therebetween and a calculating device
that is able to calculate a detection period of time during which
the valve device is in the opened state or in the closed state
based on a period of current application time between the
transmitting electrode unit and the receiving electrode unit.
[0013] The teachings herein provide the reciprocating pump taught
herein, further including: a shutout determination device that is
able to determine whether or not the valve device is in a good
shutout state and to monitor the shutout state based on the current
application between the transmitting electrode unit and the
receiving electrode unit.
[0014] The teachings herein provide the reciprocating pump taught
herein, in which the pump chamber is adapted to have a liquid
supply-side pump chamber that communicates with a liquid
supply-side suction port and a liquid supply-side discharge port
and a liquid drainage-side pump chamber that communicates with a
liquid drainage-side suction port and a liquid drainage-side
discharge port, and has a configuration in which the valve device
is provided for each of the liquid supply-side suction port, the
liquid supply-side discharge port, the liquid drainage-side suction
port, and the liquid drainage-side discharge port, the
reciprocating device reciprocates in both the liquid supply-side
pump chamber and the liquid drainage-side pump chamber, and
thereby, liquids in the liquid supply-side pump chamber and the
liquid drainage-side pump chamber are discharged from the liquid
supply-side discharge port and the liquid drainage-side discharge
port, respectively.
[0015] The teachings herein provide the reciprocating pump taught
herein, in which dialysate that is guided to a blood purification
device flows in the liquid supply-side pump chamber, dialysate
guided out from the blood purification device flows in the liquid
drainage-side pump chamber, and the reciprocating of the
reciprocating device enables dialysate to be supplied to the blood
purification device and to be guided out from the blood
purification device.
[0016] The teachings herein provide the reciprocating pump taught
herein, in which the arithmetic device obtains pump volumetric
efficiency or a flow rate in the liquid supply-side pump chamber
and in the liquid drainage-side pump chamber and is able to detect
liquid leakage between the liquid supply-side discharge port and
the liquid drainage-side suction port based on a comparison between
pump volumetric efficiency or a flow rate in the liquid supply-side
pump chamber and the pump volumetric efficiency or the flow rate in
the liquid drainage-side pump chamber.
ADVANTAGEOUS EFFECTS
[0017] According to the teachings herein, the reciprocating pump
includes the detection device that is able to detect the period of
time during which the valve device is in the opened state or in the
closed state in a predetermined cycle; and an arithmetic device
that performs an arithmetic operation to obtain the pump volumetric
efficiency or the flow rate based on a comparison between the
period of detection time detected by the detection device and the
period of time during which the valve device is in the opened state
or in the closed state in the predetermined cycle during normal
operation. Therefore, it is possible to monitor the pump volumetric
efficiency or the flow rate with ease and accuracy.
[0018] According to the teachings herein, the detection device
detects the period of time during which both the valve device on
the suction port side and the valve device on the discharge port
side are in the closed state in the predetermined cycle and the
arithmetic device performs an arithmetic operation to obtain the
pump volumetric efficiency or the flow rate based on a comparison
between the period of detection time detected by the detection
device and the period of time during which both the valve device on
the suction port side and the valve device on the discharge port
side are in the closed state in the predetermined cycle during
normal operation. Therefore, a relatively simple configuration
makes it possible to monitor the pump volumetric efficiency or the
flow rate with ease and accuracy.
[0019] According to the teachings herein, the detection device
detects the period of time during which the valve device on the
discharge side is in the opened state in the predetermined cycle
and the arithmetic device performs an arithmetic operation to
obtain the pump volumetric efficiency or the flow rate based on a
comparison between the period of detection time detected by the
detection device and the period of time during which the valve
device on the discharge side is in the opened state in the
predetermined cycle during normal operation. Therefore, it is
possible to simplify the detection by the detection device and the
arithmetic operation by the arithmetic device and it is possible to
monitor the pump volumetric efficiency or the flow rate with ease
and accuracy.
[0020] According to the teachings herein, the liquid contains the
conductive liquid and the detection device includes the
transmitting electrode unit and the receiving electrode unit which
are disposed on the pump chamber and on the flow route on the
suction port side or on the flow route on the discharge port side,
respectively, which are positioned to interpose the valve device
therebetween and a calculating device that is able to calculate a
detection period of time during which the valve device is in the
opened state or in the closed state based on a period of current
application time between the transmitting electrode unit and the
receiving electrode unit. Therefore, it is possible to monitor the
pump volumetric efficiency or the flow rate with ease and
reliability.
[0021] According to the teachings herein, the shutout determination
device that is able to determine whether or not the valve device is
in a good shutout state and to monitor the shutout state based on
the current application between the transmitting electrode unit and
the receiving electrode unit is further provided. Therefore, it is
possible to determine whether or not the shutout state is good in
addition to the pump volumetric efficiency or the flow rate and it
is possible to cause the shutout determination device to perform
monitoring by diverting the transmitting electrode unit and the
receiving electrode unit which configure the detection device.
[0022] According to the teachings herein, the pump chamber is
adapted to have the liquid supply-side pump chamber that
communicates with the liquid supply-side suction port and the
liquid supply-side discharge port, and the liquid drainage-side
pump chamber that communicates with the liquid drainage-side
suction port and the liquid drainage-side discharge port, and has a
configuration in which the valve device is provided for each of the
liquid supply-side suction port, the liquid supply-side discharge
port, the liquid drainage-side suction port, and the liquid
drainage-side discharge port, the reciprocating device reciprocates
in both the liquid supply-side pump chamber and the liquid
drainage-side pump chamber, and thereby, liquids in the liquid
supply-side pump chamber and the liquid drainage-side pump chamber
are discharged from the liquid supply-side discharge port and the
liquid drainage-side discharge port, respectively. Therefore, it is
possible to monitor the pump volumetric efficiency or the flow rate
in one of or both the pump chambers of the liquid supply-side pump
chamber and the liquid drainage-side pump chamber.
[0023] According to the teachings herein, the dialysate that is
guided to the blood purification device flows in the liquid
supply-side pump chamber, the dialysate guided out from the blood
purification device flows in the liquid drainage-side pump chamber,
and the reciprocating of the reciprocating device enables the
dialysate to be supplied to the blood purification device and to be
guided out from the blood purification device. Therefore, it is
possible to monitor that the amount of the dialysate which is
supplied to the blood purification device is reduced and it is
possible to prevent the pump volumetric efficiency from
deteriorating.
[0024] According to the teachings herein, the arithmetic device
obtains the pump volumetric efficiency or the flow rate in the
liquid supply-side pump chamber and in the liquid drainage-side
pump chamber and is able to detect liquid leakage between the
liquid supply-side discharge port and the liquid drainage-side
suction port based on a comparison between the pump volumetric
efficiency or the flow rate in the liquid supply-side pump chamber
and the pump volumetric efficiency or the flow rate in the liquid
drainage-side pump chamber. Therefore, it is possible to also
detect the liquid leakage in addition to monitoring the pump
volumetric efficiency or the flow rate in the liquid supply-side
pump chamber and the liquid drainage-side pump chamber.
BRIEF DESCRIPTION OF DRAWINGS
[0025] FIG. 1 is a diagram schematically illustrating an entire
dialysis apparatus to which a reciprocating pump according to a
first embodiment of the present invention is applied.
[0026] FIG. 2 is a three-side view illustrating the external
appearances of the reciprocating pump.
[0027] FIG. 3 is a sectional view taken along line III-III in FIG.
2.
[0028] FIG. 4 is a sectional view taken along line IV-IV in FIG.
2.
[0029] FIG. 5 is a sectional view illustrating an internal state in
a process of the reciprocating of a reciprocating device in the
reciprocating pump.
[0030] FIG. 6 is a sectional view illustrating an internal state in
the process of the reciprocating of the reciprocating device in the
reciprocating pump.
[0031] FIG. 7 is a sectional view illustrating an internal state in
the process of the reciprocating of the reciprocating device in the
reciprocating pump.
[0032] FIG. 8 is a sectional view illustrating an internal state in
the process of the reciprocating of the reciprocating device in the
reciprocating pump.
[0033] FIG. 9 is a block diagram illustrating a detection device in
the reciprocating pump.
[0034] FIG. 10 is a graph illustrating an output signal of the
detection device in the reciprocating pump, in which (a) is a graph
illustrating an output signal by a voltage-current converting
circuit, (b) is a graph illustrating an output signal by an
absolute value amplifier circuit, and (c) is a graph illustrating
an output signal by an integrating circuit.
[0035] FIG. 11 illustrates outputs of an integrating circuit on a
suction side and of an integrating circuit on a discharge side,
outputs of a voltage comparing circuit on the suction side and of a
voltage comparing circuit on the discharge side, and an output of a
logic circuit in the reciprocating pump during normal
operation.
[0036] FIG. 12 illustrates outputs of the integrating circuit on
the suction side and of the integrating circuit on the discharge
side, outputs of the voltage comparing circuit on the suction side
and of the voltage comparing circuit on the discharge side, and an
output of the logic circuit in the reciprocating pump during
abnormal operation.
[0037] FIG. 13 is a block diagram illustrating a detection device
in a reciprocating pump according to a second embodiment of the
present invention.
[0038] FIG. 14 illustrates outputs of a discharge-side integrating
circuit and of a voltage comparing circuit during normal operation
and outputs of the discharge-side integrating circuit and of the
voltage comparing circuit.
[0039] FIG. 15 is a sectional view illustrating a reciprocating
pump according to another embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0040] Hereinafter, embodiments of the present invention will be
specifically described with reference to the drawings. A
reciprocating pump according to the present embodiment is
configured of a so-called duplex pump which is applied to a blood
purification apparatus, which supplies a liquid from a liquid
supply-side pump chamber to a blood purification device, and which
causes the liquid drainage-side pump chamber to drain a dialysis
effluent from the blood purification device. The blood purification
apparatus to which the pump is applied is adapted of a hemodialysis
apparatus for performing a hemodialysis treatment on a patient and,
as illustrated in FIG. 1, is mainly configured to include a blood
circuit 3 (an arterial blood circuit and a venous blood circuit)
connected with a dialyzer 5 (blood purification device) and a
dialysis device B which has a dialysate guiding-in line L1 and a
dialysate discharging line L2.
[0041] Since the dialyzer 5 is used for purifying blood, the
dialyzer 5 is connected with each of the arterial blood circuit and
the venous blood circuit which configure the blood circuit 3, is
connected to each of the dialysate guiding-in line L1 and the
dialysate discharging line L2, and extracorporeally circulates
blood collected through an arterial puncture needle a from a
patient, though the blood circuit. After the blood is subjected to
blood purification and ultrafiltration in the dialyzer 5, the blood
returns into the patient through a venous puncture needle b. A
reference sign 6 represents an air trap chamber.
[0042] In addition, to the dialysate guiding-in line L1 and the
dialysate discharging line L2, a duplex pump 1 (reciprocating pump)
which supplies dialysate prepared to have a predetermined
concentration to the dialyzer 5 and discharges dialysate (dialysis
effluent) from the dialyzer 5 to the outside. Further, in the
dialysis device B, a plurality of bypass lines or electromagnetic
valves are disposed at arbitrary positions and an ultrafiltration
pump 2 is connected to the bypass line which causes the liquid
drainage-side pump chamber P2 (refer to FIG. 4) of the duplex pump
1 to be bypassed.
[0043] Here, as illustrated in FIGS. 2 to 4, the duplex pump 1
according to the present embodiment is mainly configured to include
a liquid supply-side pump chamber p1, the liquid drainage-side pump
chamber p2, a liquid supply-side suction port C1 which enables the
dialysate to be suctioned into the liquid supply-side pump chamber
p1, a liquid supply-side discharge port C2 which enables the
dialysate in the liquid supply-side pump chamber P1 to be
discharged, a liquid drainage-side suction port C3 which enables
the dialysate in the liquid drainage-side pump chamber P2 to be
suctioned, a liquid drainage-side discharge port C4 which enables
the dialysate in the liquid drainage-side pump chamber P2 to be
discharged, a motor M as a drive device, a plunger 7 as a
reciprocating device, check valves (J1 to J4) as valve devices, and
a monitoring device 10 which has a calculating device 11, an
arithmetic device 12 and a shutout determination device 13.
[0044] The liquid supply-side pump chamber P1 is formed of an
accommodation space having a predetermined volume which enables the
dialysate (liquid which is adapted of an electrolyte) suctioned
from the liquid supply-side suction port C1 to flow and to be
discharged from the liquid supply-side discharge port C2 due to the
reciprocating of the plunger 7. Similarly, the liquid drainage-side
pump chamber P2 is formed of an accommodation space having a
predetermined volume which enables the dialysate suctioned from the
liquid drainage-side suction port C3 to flow and to be discharged
from the liquid drainage-side discharge port C4 due to the
reciprocating of the plunger 7. In addition, each of the liquid
supply-side suction port C1 and the liquid supply-side discharge
port C2 is connected with piping which configures the dialysate
guiding-in line L1 and each of the liquid drainage-side suction
port C3 and the liquid drainage-side discharge port C4 is connected
with piping which configures the dialysate discharging line L2.
[0045] The plunger 7 is able to reciprocate with respect to the
liquid supply-side pump chamber P1 and the liquid drainage-side
pump chamber P2 by the motor M, the reciprocating enables the
dialysate to be suctioned into the liquid supply-side pump chamber
P1 and the liquid drainage-side pump chamber P2 from the liquid
supply-side suction port C1 and the liquid drainage-side suction
port C3, respectively, and enables the dialysate to be discharged
from the liquid supply-side discharge port C2 and the liquid
drainage-side discharge port C4, respectively.
[0046] To be more specific, as illustrated in FIGS. 3 and 4, a cam
member 8 is attached to an output shaft Ma of the motor M and a
protruding cam portion 8a is formed at a position (position shifted
from the rotational center) different from an axial line of the
output shaft Ma. The cam member 8 is positioned in a recessed
portion 7a formed in the plunger 7 in a state in which the motor M
is assembled thereto. In addition, when a block slider 9 is
attached to the cam portion 8a and the motor M is driven, the block
slider 9 presses the plunger 7 in a longitudinal direction such
that the plunger 7 is caused to reciprocate in a rightward-leftward
direction in FIG. 3.
[0047] The check valves (J1 and J2) are formed of a no-current
applicable valve (valve formed of an insulating material) which has
a function of maintaining the flow of the dialysate in one
direction (upward in FIG. 4) such that back flow is prevented, and
are configured to be disposed between the liquid supply-side pump
chamber P1 and a flow route on the liquid supply-side suction port
C1 side and a flow route on the liquid supply-side discharge port
C2 side, respectively, are openable and closable in response to a
change in a liquid pressure in the liquid supply-side pump chamber
P1 due to the reciprocating of the plunger 7, allow the dialysate
to flow in an opened state, and block the dialysate from flowing in
a closed state.
[0048] Similarly, the check valves (J3 and J4) are formed of a
no-current applicable valve (valve formed of an insulating
material) which has a function of maintaining flow of the dialysate
in one direction (upward in FIG. 4) such that back flow is
prevented, and are configured to be disposed between the liquid
drainage-side pump chamber P2 and a flow route on the liquid
drainage-side suction port C3 side and a flow route on the liquid
drainage-side discharge port C4 side, respectively, are openable
and closable in response to a change in a liquid pressure in the
liquid drainage-side pump chamber P2 due to the reciprocating of
the plunger 7, allow the dialysate to flow in the opened state, and
block the dialysate from flowing in the closed state.
[0049] Thus, in a process in which the plunger 7 is shifted to the
left side in the drawing to reach an end portion (shifted end) on
the liquid drainage-side pump chamber P2 side, when the motor M is
driven, as illustrated in FIG. 5, the check valve J1 on the liquid
supply-side suction port C1 side and the check valve J4 on the
liquid drainage-side discharge port C4 side enter into the opened
state and the check valve J2 on the liquid supply-side discharge
port C2 side and the check valve J3 on the liquid drainage-side
suction port C3 side enter into the closed state. Then, when the
plunger 7 reaches the left end (shifted end) in the drawing, as
illustrated in FIG. 6, all of the check valves (J1 to J4) enter
into the closed state.
[0050] Then, in a process in which the plunger 7 is shifted to the
right side in the drawing to reach an end portion (shifted end) on
the liquid supply-side pump chamber P1 side, as illustrated in FIG.
7, the check valve J2 on the liquid supply-side discharge port C2
side and the check valve J3 on the liquid drainage-side suction
port C3 side enter into the opened state and the check valve J1 on
the liquid supply-side suction port C1 side and the check valve J4
on the liquid drainage-side discharge port C4 side enter into the
closed state. Then, when the plunger 7 reaches the right end
(shifted end) in the drawing, as illustrated in FIG. 8, all of the
check valves (J1 to J4) enter into the closed state. Thereafter,
the same opening and closing operation of the check valves (J1 to
J4) are performed due to the reciprocating of the plunger 7.
[0051] The detection device can detect a period of time during
which the check valves (J1 to J4) are in the opened state or in the
closed state in a predetermined cycle (according to the present
embodiment, one logical cycle when a shot is performed or an
opening/closing cycle of the check valve). According to the present
embodiment, the detection device is configured to include a
transmitting electrode unit Sa and receiving electrode units (S1
and S2) which are disposed on the liquid supply-side pump chamber
P1 and on the flow route on the liquid supply-side suction port C1
or on the flow route on the liquid supply-side discharge port C2
side, respectively, which are positioned to interpose the check
valves (J1 and J2) therebetween, a transmitting electrode unit Sb
and receiving electrode units (S3 and S4) which are disposed on the
liquid drainage-side pump chamber P2 and on the flow route on the
liquid drainage-side suction port C3 side or on the flow route on
the liquid drainage-side discharge port C4 side, respectively,
which are positioned to interpose the check valves (J3 and J4)
therebetween. That is, the detection device according to the
present embodiment is configured to include the electrode portions
(S1 to S4 and Sa and Sb) and a calculating device 11.
[0052] Specifically, the transmitting electrode unit Sa is formed
of a conductive member which configures a part of the liquid
supply-side pump chamber P1 and is formed of a conductive electrode
member to which the receiving electrode unit S1 is attached to face
the flow route (flow route closer to the liquid supply-side suction
port C1 side than a provided position of the check valve J1) in the
vicinity of the liquid supply-side suction port C1 and the
receiving electrode unit S2 is attached to face the flow route
(closer to the liquid supply-side discharge port C2 side than a
provided position of the check valve J2) in the vicinity of the
liquid supply-side discharge port C2.
[0053] In addition, the transmitting electrode unit Sb is formed of
a conductive member which configures a part of the liquid
drainage-side pump chamber P2 and is formed of a conductive
electrode member to which the receiving electrode unit S3 is
attached facing the flow route (flow route closer to the liquid
drainage-side suction port C3 side than a provided position of the
check valve J3) in the vicinity of the liquid drainage-side suction
port C3 and the receiving electrode unit S4 is attached to face the
flow route (closer to the liquid drainage-side discharge port C4
side than a provided position of the check valve J4) in the
vicinity of the liquid drainage-side discharge port C4.
[0054] In the process in which the plunger 7 reciprocates, when the
check valves J1 and J4 enter into the opened state and the check
valves J2 and J3 enter into the closed state, the current is
applied to the transmitting electrode unit Sa and the receiving
electrode unit S1, and the transmitting electrode unit Sb and the
receiving electrode unit S4 and no current is applied to the
transmitting electrode unit Sa and the receiving electrode unit S2,
or to the transmitting electrode unit Sb and the receiving
electrode unit S3 because the dialysate contains a conductive
liquid and the check valves J1, J2, J3, and J4 are formed of a
no-current applicable material. Further, in the process in which
the plunger 7 reciprocates, when the check valves J2 and J3 enter
into the opened state and the check valves J1 and J4 enter into the
closed state, no current is applied to the transmitting electrode
unit Sa and the receiving electrode unit S1, or the transmitting
electrode unit Sb and the receiving electrode unit S4 and the
current is applied to the transmitting electrode unit Sa and the
receiving electrode unit S2, and to the transmitting electrode unit
Sb and the receiving electrode unit S3 because the dialysate
contains a conductive liquid and the check valves J1, J2, J3, and
J4 are formed of a no-current applicable material.
[0055] The calculating device 11 is able to calculate a period of
detection time during which the check valves (J1 to J4) are in the
opened state or in the closed state, based on a period of current
application time between the transmitting electrode units (Sa and
sb) and the receiving electrode units (S1 to S4). Therefore,
according to the present embodiment, as illustrated in FIG. 9, the
calculating device 11 is configured to include a single
transmitting circuit, a pair of current-voltage converting
circuits, a pair of absolute value amplifier circuits, a pair of
integrating circuits, a pair of voltage comparing circuits, a
single logic circuit, and an arithmetic unit. In the same drawing,
the calculating device includes two of a suction-side calculating
device on the liquid supply-side suction port C1 side and an
discharge-side calculating device on the liquid supply-side
discharge port C2 side on the liquid supply-side pump chamber P1
side, which are depicted in the drawing; similarly, in the present
embodiment, the calculating device 11 has two of a suction-side
calculating device on the liquid drainage-side suction port C3 side
and an discharge-side calculating device on the liquid
drainage-side discharge port C4 side on the liquid drainage-side
pump chamber P2. Hereinafter, the flow routes on the liquid
supply-side suction port C1 side and the liquid supply-side
discharge port C2 side on the liquid supply-side pump chamber P1
side will be described; and the same is true of the liquid
drainage-side pump chamber P2 side.
[0056] For example, as illustrated in FIG. 10, an electrical signal
detected by the transmitting circuit is converted into a waveform
(refer to the same drawing (a)) of a voltage in the current-voltage
converting circuit, a waveform as illustrated in (b) in the same
drawing is formed in the absolute value amplifier circuit, and
then, a waveform as illustrated in (c) in the same drawing is
formed in the integrating circuit. Thus, as illustrated in FIGS. 11
and 12, the electrical signal detected in the transmitting circuit
is subjected to a process by the integrating circuit of the
suction-side calculating device and the integrating circuit of the
discharge-side calculating device, then, a waveforms as illustrated
in FIGS. 11 and 12 (upper two waveforms in the same drawing) are
output and the output waveforms are subjected to a process by the
voltage comparing circuit of the suction-side calculating device
and by the voltage comparing circuit of the discharge-side
calculating device such that two-value signals (signals formed of
two high and low levels) are formed (refer to the third and fourth
waveforms from the top in the same drawing). In the same drawing,
the high and low levels of the signal are inverted into the
two-value output.
[0057] The logic circuit compares the output by the voltage
comparing circuit of the suction-side calculating device with the
output by the voltage comparing circuit of the discharge-side
calculating device such that a waveform showing a timing at which
both outputs have the high level (that is, both the check valve J1
on the liquid supply-side suction port C1 side and the check valve
J2 on the liquid supply-side discharge port C2 side are in the
closed state) is output (refer to the lowermost waveform in the
same drawing). Thus, the arithmetic unit calculates a period of
time (referred to as a detection time) during which the check valve
J1 and the check valve J2 are in the closed state in a
predetermined cycle (in this case, an opening/closing cycle of the
check valve), based on the waveform output from the logic
circuit.
[0058] The arithmetic device 12 performs an arithmetic operation to
obtain pump volumetric efficiency (efficiency of one shot when the
liquid is discharged in the reciprocating pump (metering pump)) or
a flow rate by a predetermined arithmetic operation based on a
comparison between the period of detection time detected by the
detection device and a period of time (period of time as a measured
value or a theoretical period of time during normal operation)
during which the check valves (J1 and J2) are in the closed state
in the predetermined cycle during normal operation. For example, in
a case where the arithmetic device 12 performs the arithmetic
operation to obtain the pump volumetric efficiency, it is possible
to use an arithmetic equation as follows. An arithmetic equation 1
is used for obtaining the pump volumetric efficiency and an
arithmetic equation 2 is used for obtaining the flow rate.
Pump Volumetric Efficiency (%)=(.DELTA.T-TLL)/(.DELTA.T-Initial
TLL) (Arithmetic Equation 1)
[0059] Here, .DELTA.T represents a period of logical one-cycle time
or an opening/closing cycle of the check valve, TLL represents a
period of detection time (period of time during which both the
check valve on the suction side and the check valve on the
discharge side are in the closed state in one cycle), and initial
TLL represents a period of time during which both the check valve
on the suction side and the check valve on the discharge side are
in the closed state in one cycle during normal operation.
Flow Rate (mL/min)=(.DELTA.T-TLL)/(.DELTA.T-Initial TLL).times.QD
(Arithmetic Equation 2)
[0060] Here, QD (mL/min)=one shot of a reciprocating pump (metering
pump).times.60.times.1/.DELTA.T(mL/min), and the other parameters
are the same as arithmetic equation 1.
[0061] Meanwhile, the shutout determination device 13 is able to
determine whether or not the shutout states of the check valves (J1
to J4) are good based on the current application between the
transmitting electrode units (Sa and Sb) and the receiving
electrode units (S1 to S4). That is, the current application
between the transmitting electrode units (Sa and Sb) and the
receiving electrode units (S1 to S4) is performed at a
predetermined timing in response to the reciprocating of the
plunger 7. When the shutout of check valves (J1 to J4) is not good,
a period of no-current applicable time between the transmitting
electrode units (Sa and Sb) and the receiving electrode units (S1
to S4) in which the check valves (J1 to J4) are formed. Therefore,
the shutout determination device 13 determines the change and
thereby it is possible to monitor the shutout state of the check
valves (J1 to J4).
[0062] In addition, the arithmetic device 12 obtains pump
volumetric efficiency or a flow rate of the liquid supply-side pump
chamber P1 and the liquid drainage-side pump chamber P2 and may be
able to detect liquid leakage from the flow route between the
liquid supply-side discharge port C2 and the liquid drainage-side
suction port C3 through the dialyzer 5, based on a comparison
between the pump volumetric efficiency or the flow rate of the
liquid supply-side pump chamber P1 and the pump volumetric
efficiency or the flow rate of the liquid drainage-side pump
chamber P2. In this case, it is possible to detect the liquid
leakage from the flow route between the liquid supply-side
discharge port C2 and the liquid drainage-side suction port C3
through the dialyzer 5, in addition to monitoring the pump
volumetric efficiency or the flow rate of the liquid supply-side
pump chamber P1 and the liquid drainage-side pump chamber P2.
[0063] Hereinafter, a second embodiment according to the present
invention will be described. Similar to the first embodiment, the
reciprocating pump according to the present embodiment is formed of
a so-called duplex pump which is applied to a blood purification
apparatus, which supplies a liquid from a liquid supply-side pump
chamber to a blood purification device, and which causes the liquid
drainage-side pump chamber to discharge dialysis effluent from the
blood purification device. Since a main configuration in the blood
purification apparatus and the duplex pump 1 to which the
reciprocating pump is applied (components other than the
calculating device 11 and the arithmetic device 12) is the same as
that in the first embodiment, the description thereof is
omitted.
[0064] As illustrated in FIG. 13, the calculating device 11'
according to the present embodiment is configured to include a
single transmitting circuit, a single current-voltage converting
circuit, a single absolute value amplifier circuit, a single
integrating circuit, a single voltage comparing circuit, and an
arithmetic unit. In the same drawing, the calculating device
includes only one circuit on the liquid supply-side discharge port
C2 side in the liquid supply-side pump chamber P1 side, which are
depicted in the drawing; and similarly, in the present embodiment,
the calculating device also include the circuit on the liquid
drainage-side discharge port C4 in the liquid drainage-side pump
chamber P2 side. Hereinafter, the circuit on the liquid supply-side
discharge port C2 side in the liquid supply-side pump chamber P1
side will be described and the same is true of the liquid
drainage-side pump chamber P2 side. During normal operation, the
electrical signal detected in the transmitting circuit is processed
in the integrating circuit, a waveform as illustrated on the top in
FIG. 14 is output, and the output waveform is changed in the
voltage comparing circuit to have two values (processed to form a
signal having two high and low signals), the second waveform output
from the top as illustrated in the same drawing is obtained.
[0065] However, the electrical signal detected in the transmitting
circuit is processed in the integrating circuit during usage
process of the reciprocating pump, the second waveform from below
as illustrated in FIG. 14 is output, the output waveform is
processed in the voltage comparing circuit to have two values
(processed to a signal formed of two high and low levels), and the
lowermost output as illustrated in the same drawing is achieved.
The arithmetic device can perform an arithmetic operation to obtain
the pump volumetric efficiency (efficiency of one shot when the
liquid is discharged in the reciprocating pump (metering pump)) or
a flow rate based on the output obtained during normal operation
and the output obtained during abnormal operation. Hereinafter, the
arithmetic equations of the present embodiment (an arithmetic
equation 3 is used for obtaining the pump volumetric efficiency and
an arithmetic equation 4 is used for obtaining the flow rate) will
be described.
Pump Volumetric Efficiency (%)=(TH)/(Initial TH) (Arithmetic
Equation 3)
[0066] Here, TH represents a period of detection time (period of
time during which the check valve on the discharge side is in the
opened state in one cycle), and initial TH represents a period of
time during which the check valve on the discharge side is in the
opened state in one cycle during normal operation.
Flow Rate (mL/min)=TH/Initial TH.times.QD (Arithmetic Equation
4)
[0067] Here, QD (mL/min)=one shot of a reciprocating pump (metering
pump)+60.times.1/.DELTA.T(mL/min), and the other parameters are the
same as arithmetic equation 3.
[0068] According to the first embodiment and the second embodiment,
the detection device (transmitting electrode units Sa and Sb and
receiving electrode units (S1 to S4)) which can detect a period of
time during which the check valves (J1 to J4) are in the opened
state or in the closed state in the predetermined cycle and the
arithmetic device 12 which performs the arithmetic operation to
obtain the pump volumetric efficiency and the flow rate based on a
comparison between the detection time detected in the detection
device and the period of time during which the check valves (J1 to
J4) are in the opened state or in the closed state in the
predetermined cycle during normal operation. Therefore, it is
possible to monitor the pump volumetric efficiency or the flow rate
with ease and accuracy.
[0069] In addition, the liquid contains the conductive liquid (that
is, dialysate) and the detection device includes the transmitting
electrode units (Sa and Sb) and the receiving electrode units (S1
to S4) which are disposed on the pump chambers (liquid supply-side
pump chamber P1 and the liquid drainage-side pump chamber P2) and
on the flow route on the suction ports (C1 and C3) side or on the
flow route on the discharge port (C2 and C4) side, respectively,
which are positioned to interpose the check valves (J1 to J4)
therebetween and a calculating device (11 or 11') that is able to
calculate a detection period of time during which the check valves
(J1 to J4) are in the opened state or in the closed state based on
a period of current application time between the transmitting
electrode units (Sa and Sb) and the receiving electrode units (S1
to S4). Therefore, it is possible to monitor the pump volumetric
efficiency or the flow rate with ease and reliability.
[0070] The shutout determination device 13 that is able to
determine whether or not the check valves (J1 to J4) are in a good
shutout state and to monitor the shutout state based on the current
application between the transmitting electrode units (Sa and Sb)
and the receiving electrode units (S1 to S4) is provided.
Therefore, it is possible to determine whether or not the shutout
state is good in addition to the pump volumetric efficiency or the
flow rate and it is possible to cause the shutout determination
device 13 to perform monitoring by diverting the transmitting
electrode units (Sa and Sb) and the receiving electrode units (S1
to S4) which configure the detection device.
[0071] Further, the pump chamber is adapted to have the liquid
supply-side pump chamber P1 that communicates with the liquid
supply-side suction port C1 and the liquid supply-side discharge
port C2 and the liquid drainage-side pump chamber P2 that
communicates with the liquid drainage-side suction port C3 and the
liquid drainage-side discharge port C4, and has a configuration in
which the check valves (J1 to J4) are provided for each of the
liquid supply-side suction port C1, the liquid supply-side
discharge port C2, the liquid drainage-side suction port C3, and
the liquid drainage-side discharge port C4, the plunger 7
(reciprocating device) reciprocates in both the liquid supply-side
pump chamber P1 and the liquid drainage-side pump chamber P2, and
thereby, dialysate (liquids) in the liquid supply-side pump chamber
P1 and the liquid drainage-side pump chamber P2 is discharged from
the liquid supply-side discharge port C2 and the liquid
drainage-side discharge port C4, respectively. Therefore, it is
possible to monitor the pump volumetric efficiency or the flow rate
in one of or both the pump chambers of the liquid supply-side pump
chamber P1 and the liquid drainage-side pump chamber P2.
[0072] The dialysate that is guided to the dialyzer 5 (blood
purification device) flows in the liquid supply-side pump chamber
P1, the dialysate guided out from the dialyzer 5 flows in the
liquid drainage-side pump chamber P2, and the reciprocating of the
plunger 7 (reciprocating device) enables the dialysate to be
supplied to the dialyzer 5 and to be guided out from the dialyzer
5. Therefore, it is possible to monitor that the amount of the
dialysate which is supplied to the dialyzer 5 is reduced and it is
possible to prevent the pump volumetric efficiency from
deteriorating.
[0073] Specifically, according to the first embodiment, the
detection device detects a period of time during which both the
check valve J1 on the suction port side and the check valve J2 on
the discharge port side are in the closed state in the
predetermined cycle and the arithmetic device 12 performs an
arithmetic operation to obtain the pump volumetric efficiency or
the flow rate based on a comparison between the period of detection
time detected by the detection device and the period of time during
which both the check valve J1 on the suction port side and the
check valve J2 on the discharge port side are in the closed state
in the predetermined cycle during normal operation. Therefore, a
relatively simple configuration makes it possible to monitor the
pump volumetric efficiency or the flow rate with ease and
accuracy.
[0074] In addition, according to the second embodiment, the
detection device detects the period of time during which the check
valve J2 on the discharge port side is in the opened state in the
predetermined cycle and the arithmetic device 12 performs an
arithmetic operation to obtain the pump volumetric efficiency or
the flow rate based on a comparison between the period of detection
time detected by the detection device and the period of time during
which the check valve J2 on the discharge port side is in the
opened state in the predetermined cycle during normal operation.
Therefore, it is possible to simplify the detection by the
detection device and the arithmetic operation by the arithmetic
device and it is possible to monitor the pump volumetric efficiency
or the flow rate with ease and accuracy.
[0075] As above, the present embodiment is described; however, the
present invention is not limited thereto and, for example, instead
of the check valves (J1 to J4), another shape of a valve device may
be used or the shutout determination device 13 may not be provided.
The apparatus to which the valve device is applied is not limited
to the blood purification apparatus (hemodialysis apparatus) as in
the present embodiment and, in this case, the liquid which flows in
the pump chamber is not limited to the dialysate.
[0076] In addition, as long as the reciprocating pump includes the
detection device that is able to detect a period of time during
which the valve device is in the opened state or in the closed
state in a predetermined cycle; and an arithmetic device that
performs an arithmetic operation to obtain the pump volumetric
efficiency or the flow rate based on the comparison between the
period of detection time detected by the detection device and a
period of time during which the valve device is in the opened state
or in the closed state in the predetermined cycle during normal
operation, the invention may be applied to another shape of a
pump.
[0077] For example, as illustrated in FIG. 15, the present
invention may be applied to the ultrafiltration pump 2 that
includes a single pump chamber P3 which is able to flow a liquid, a
suction port C5 which enables a liquid to be suctioned into the
pump chamber P3, an discharge port C6 which enable a liquid in the
pump chamber P3 to be discharged, a plunger 14 (reciprocating
device) which is capable of reciprocating in the pump chamber P3 by
the drive device such as the motor M and enables a liquid to be
suctioned into the pump chamber P3 from the suction port C5 and
enables the liquid to be discharged from the discharge port C6 due
to the reciprocating, and check valves (J5 and J6) (valve devices)
which are disposed between the pump chamber P3 and a flow route on
the suction port C5 side and a flow route on the discharge port C6
side, are openable and closable in response to a change in a liquid
pressure in the pump chamber P3, which is produced due to the
reciprocating of the plunger 14, allow a liquid to flow in the
opened state, and block a liquid from flowing in the closed
state.
[0078] In this case, it is preferable that the calculating device
11 that configures the detection device calculates a period of
detection time during which the check valves (J5 and J6) are in the
opened state or in the closed state based on a period of current
application time between a transmitting electrode unit Sc and
receiving electrode units (S5 and S6) and the arithmetic device 12
performs an arithmetic operation to obtain pump volumetric
efficiency or a flow rate based on the period of detection time
detected by the detection device and the period of time during
which the check valves (J5 and J6) are in the opened state or in
the closed state in the predetermined cycle during normal
operation.
[0079] As long as a reciprocating pump includes a detection device
that is able to detect a period of time during which the valve
device is in the opened state or in the closed state in a
predetermined cycle; and an arithmetic device that performs an
arithmetic operation to obtain pump volumetric efficiency or a flow
rate based on a comparison between the period of detection time
detected by the detection device and a period of time during which
the valve device is in the opened state or in the closed state in
the predetermined cycle during normal operation, the invention may
be applied to another pump having a different external appearance
or a pump to which another function is added.
REFERENCE SIGNS LIST
[0080] 1 duplex pump (reciprocating pump)
[0081] 2 ultrafiltration pump (reciprocating pump)
[0082] 3 blood circuit
[0083] 4 blood pump
[0084] 5 dialyzer (blood purification device)
[0085] 6 air trap chamber
[0086] 7 plunger (reciprocating device)
[0087] 8 cam member
[0088] 9 block slider
[0089] 10 monitoring device
[0090] 11 calculating device (detection device)
[0091] 12 arithmetic device
[0092] 13 shutout determination device
[0093] 14 plunger (reciprocating device)
[0094] J1 to J6 check valve (valve device)
[0095] P1 liquid supply-side pump chamber
[0096] P2 liquid drainage-side pump chamber
[0097] C1 liquid supply-side suction port
[0098] C2 liquid supply-side discharge port
[0099] C3 liquid drainage-side suction port
[0100] C4 liquid drainage-side discharge port
[0101] Sa, Sb transmitting electrode unit (detection device)
[0102] S1 to S4 receiving electrode unit (detection device)
* * * * *