JPH06154309A - Fluid feed pumping device - Google Patents

Abstract

PURPOSE:To secure a fixed discharge flow rate by providing plural pieces (m) of pumps, driving them by the phase difference of 1/m of a pulsation period and also, correcting target pressure based on the result of detection of a discharge termination before and after a switching timing from discharge to the suction of each pump. CONSTITUTION:This pumping device is provided with two pumps 7a, 7b driven by the phase difference of 1/2, and these pumps 7a, 7b have sacks 5a, 5b driven to invert by a fact that air receiving spaces 7pa, 7pb are connected selectively to a high pressure source or a negative pressure source by solenoid opening/ closing valves 8a, 8b, and by the inversion of the sacks 5a, 5b, blood sucked into blood receiving spaces 7fa, 7fb is discharged. The solenoid opening/closing valves 8a, 8b are controlled, based on target high pressure and target low pressure, and in this case, when a discharge termination is detected before switching from discharge to suction, the target high pressure is corrected to a lower level and in the case of not becoming the discharge termination at a switching time point, the pressure is corrected to a higher level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid feed pumping device for pressurizing and delivering a fluid arriving at a fluid receiving port. The present invention relates to a pumping device that is driven by extracorporeal circulation at a substantially constant flow rate.

[0002]

2. Description of the Related Art For assisting the operation of the heart, for example, an artificial heart that sucks the blood of the heart and sends it to the aorta is known. However, a suction negative pressure higher than the blood sending capacity of the heart is applied to the heart. Is unfavorable as it adds a large external effect to the heart. Therefore, it may be desirable to pump the amount of blood pumped by the heart to the aorta while maintaining that amount of pressure and to substantially assist only the discharge of the heart.

In Japanese Patent Application Laid-Open No. 62-94171, two pumps are connected in parallel to each other and are inserted between the left atrium of the heart and the aorta, and one pump contains blood discharged by the heart. A pumping device has been proposed which pressurizes the other pump during the period of time (inhalation period) to pressurize the blood contained therein to the aorta (delivery period), and repeats this alternately. Each pump includes a working pressure chamber to which a driving pressure is applied and a sack that is inside the working pressure chamber and encloses the blood receiving space. During the inhalation period, the working pressure chamber of the pump is released to the atmospheric pressure so as not to apply an excessive negative pressure to the heart, and blood naturally enters the blood receiving space in the suck of the pump by the discharge pressure of the heart. Suck is
Depending on the pressure in the working pressure chamber, it contracts when it is higher than atmospheric pressure to contract the blood receiving space, and when the working pressure chamber is released to atmospheric pressure, the sac expands due to the pressure of blood flowing into the blood receiving space. The blood receiving space expands. To monitor the contraction / expansion movement of the sack, the position of the largest reciprocating motion of the sack is detected, and it corresponds to the time from the end of suction of one pump to the end of discharge of the other pump. So that the time becomes substantially zero, that is, when the suction of one pump ends, the discharge of the other pump ends, and at this time, the suction period and the discharge period of both pumps are switched, The positive pressure value given to both pumps is adjusted. As a result, blood is pressurized and delivered to the aorta by the pumping device without disturbing the discharge flow rate of the heart, and further, the pumping delivery flow rate (driving flow rate) changes automatically following the fluctuation of the discharge flow rate of the heart. Therefore, this pumping does not impose a particular burden on the heart, and realizes blood delivery assistance that automatically adapts to the operating state of the heart, that is, the physiological state of the living body, in particular its change.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
When biological blood is driven to extracorporeally circulate for cardiac surgery or the like, it is required to send blood at a required constant flow rate (external circulation drive), and the pumping device as described above cannot meet this type of requirement.

According to the present invention, as described above, a pump provided with a pumping member such as a sack capable of reciprocating the fluid receiving space and the working fluid space and reciprocating in the direction of contracting / expanding the fluid receiving space substantially has an inflow rate. In a pumping device that pressurizes and delivers a fluid at an equal flow rate, it is an object to make the driving flow rate of the pumping device substantially constant.

[0006]

The pumping device of the present invention divides the fluid receiving space (7fa / 7fb) from the working fluid space (7pa / 7pb) and contracts / expands the fluid receiving space (7fa / 7fb). Pumping body (5a / 5b), fluid receiving port (2
3) and fluid receiving space (7fa / 7fb) are inserted between the check valve (3a / 3b), which allows the passage of fluid from the former to the latter and blocks the passage in the opposite direction, and the fluid delivery Outlet (24) and fluid receiving space (7f
a) and a check valve (4a / 4b) that is inserted between (a / 7fb) and that allows the fluid to flow from the latter to the former but prevents the fluid from flowing in the reverse direction. ) Pump (7a / 7b); detection means (1a, 13a, 18 / 1b, for detecting the end of discharge and end of suction of at least one of the plurality of pumps (7a / 7b)
13b, 18); high pressure fluid source (9P, 10P, 11p, 11m); the high pressure fluid source (9
Pressure control means (14c, 18) for setting pressure of P, 10P, 11p, 11m) to a designated target high pressure (Pp); low pressure fluid source (9
N, 10N, 11p, 11m); the low-pressure fluid source (9N, 10N,
11p, 11m) pressure control means (14d, 18) for setting a specified target low pressure (Pn); the working fluid spaces of the plurality of pumps are selectively connected to a high pressure fluid source and a low pressure fluid source. Switching means (8a / 8b) for determining the pulsation cycle (2Th) (22,1
8); and the switching means for pulsating the plurality of m (1/2) pumps (7a / 7b) with a phase difference (Th) of 1 / m of the pulsation period (2Th). 8a / 8b) is switched and energized, and the detection means
(1a, 13a, 18 / 1b, 13b, 18) the target high pressure (1a, 13a, 18b, 13b, 18) in response to the detection of the end of discharge of the detection means before the timing of switching from discharge to suction of the pump (7a / 7b) Pp) is updated to a low value, and the target high pressure (Pp) is updated to a high value in response to non-detection of the discharge end of the detection means at the switching timing, so that the detection target pump of the detection means changes from suction to discharge. The target low pressure (Pn) is updated to high in response to the detection of the end-of-suction end of the detection means before the switching timing, and the target low pressure (Pn) is updated in response to non-detection of the end-of-suction end of the detection means at the switching timing. Flow rate control means (18) for updating the pressure (Pn) to a low level;
Equipped with. Symbols or languages in parentheses are symbols or corresponding matters attached to corresponding elements in the embodiments described later with reference to the drawings.

[0007]

[Operation] When m = 2, that is, the case where the first pump (7a) and the second pump (7b) are used is explained as an example, the flow rate control means (18) controls these pumps (7a / 7b). Beat cycle 2Th
Switching means (8a / 8b) so as to drive with a phase difference Th of 1/2
These pumps (7a / 7b) alternately deliver the fluid, with one being a discharge and the other being a suction. Therefore, fluctuations in the fluid delivery pressure are smaller than when using a single pump. Note that when m ≧ 3, the fluctuation becomes smaller.

The flow rate control means (18) is provided with detection means (1a, 13a, 18
/ 1b, 13b, 18) detection target pump (7a / 7b) responds to the detection of the end of discharge (detection position ≥Ps) by the detection means before the timing of switching from discharge to suction of the target high pressure (Pp ) Updated lower
(Pp ← Pp−1), and the target high pressure (Pp) is updated to a high value (Pp ← Pp + 1) in response to non-detection (detection position <Ps) of the discharge end of the detection means at the switching timing, When the flow rate is higher than the constant discharge flow rate, the high pressure of the high-pressure fluid source is lowered, and when the flow rate is low, the high pressure is raised. This results in a constant discharge flow rate on a time series average.

Further, the flow rate control means (18) includes a detection means (1a,
13a, 18 / 1b, 13b, 18) detection target pump (7a / 7b) in response to detection of the end of inhalation (detection position ≤ Pe) by the detection means before the timing of switching from suction to discharge. The pressure (Pn) is updated to a high value (Pe ← Pe + 1), and the target low pressure (Pn) is updated to a low value (Pn ←) in response to non-detection (detection position> Pe) at the end of inhalation of the detection means at the switching timing. Pn−1), the low pressure of the low-pressure fluid source is raised when the flow rate becomes higher than the constant suction flow rate, and the low pressure is lowered when the flow rate becomes low. This results in a constant inhalation flow rate on a time series average.

The pressure adjustment of the high-pressure fluid source and the pressure adjustment of the low-pressure fluid source are complementary to each other. For example, if the pressure of the high-pressure fluid source is increased in order to maintain a constant discharge flow rate, the discharge will be faster, and if the pressure of the low-pressure fluid source remains unchanged, the suction will be delayed, but the pressure adjustment of the low-pressure fluid source described above will delay the suction. Since the pressure of the low-pressure fluid source is reduced to compensate, if the pressure of the high-pressure fluid source is increased to maintain a constant discharge flow rate, the pressure of the low-pressure fluid source will be reduced in conjunction with this, and the discharge flow rate and suction flow rate will be reduced. Automatically balances.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0012]

1 and 2 show an embodiment of the present invention.
FIG. 1 shows pumps 7a, 7b and electromagnetic switching valves 8a, 7a, 7b for alternately applying negative pressure (low pressure) and high pressure air (high pressure) to them.
8b, FIG. 2 shows the negative and high pressure air-sources and controls. It should be noted that by overlapping the same circled symbols in FIG. 1 and the circled symbols in FIG. 2, an overall view of one embodiment appears.

The inner space of the first pump 7a is divided by a suck 5a into a blood (fluid) receiving space 7fa and an air (working fluid) receiving space 7pa. The air receiving space 7pa passes through the air port 6a and the output port of the first electromagnetic switching valve 8a.
Connected to the network. A high pressure accumulator 9P is connected to the high pressure input port of the first electromagnetic switching valve 8a, and a negative pressure accumulator 9N is connected to the low pressure input port of the first electromagnetic switching valve 8a. When the coil is energized, the valve member is driven to output the output port (7 pa) to the high voltage input port.
Although it is connected to the port (accumulator 9P), the compression coil spring drives the valve member back to drive the output port (7pa) when the power is not supplied to the low-voltage input port (accumulator 9P).
N).

The high-pressure accumulator 9P has an electromagnetic opening / closing valve 1
Output port of 0P is connected, low pressure accumulator 9N
An output port of the solenoid on-off valve 10N is connected to the.
The discharge port (high-pressure air supply port) of the air pump 11p driven by the electric motor 11m is connected to the input port of the electromagnetic opening / closing valve 10P, and the air is supplied to the input port of the electromagnetic opening / closing valve 10N. -The suction port of the pump 11p is connected. In addition,
Although not shown, a high pressure release valve for releasing an overpressure to the atmosphere is connected to the discharge port of the air-pump 11p, and a negative pressure release valve for allowing the inflow of the atmosphere at the time of overnegative pressure is connected to the suction port of the pump 11p. There is. When the electric coil of the electromagnetic on-off valve 10P is energized, the valve member is driven to connect the output port to the input port, and the accumulator 9P is supplied with the discharge pressure of the air pump 11p to electromagnetically open and close. When the electric coil of the valve 10N is energized, the valve member is driven to connect the output port to the input port, and the suction pressure of the air pump 11p is applied to the accumulator 9N. When the electric coils of the solenoid on-off valves 10P and 10N are not energized, the compression coil spring drives the valve member back to shut off the discharge port and the suction port of the pump 11p from the accumulators 9P and 9N. While the pumps 7a and 7b are being driven, the internal pressures of the accumulators 9P and 9N are detected by the pressure sensors 9ps and 9ns, respectively. When the detected pressure of 9ps is lower than the high pressure target value (Pp), the solenoid opening / closing valve 10P opens. However, the internal pressure of the accumulator 9P is constantly maintained substantially at the high pressure target value (Pp) by being closed when the temperature is high. When the detected pressure of 9 ns is higher than the low pressure target value (Pn), the solenoid on-off valve 10N is opened, and when it is low, the solenoid on-off valve 10N is closed, and the internal pressure of the accumulator 9N is always maintained substantially at the low pressure target value (Pn).

Therefore, when the first electromagnetic switching valve 8a is energized (turned on), the air-receiving space 7p of the first pump 7a.
Air having a high-pressure target value (Pp) is supplied to a, and the sack 5a is pushed in a direction in which the blood receiving space 7fa is contracted (a direction toward a position indicated by a chain double-dashed line in FIG. 1a) (discharging step), When the first electromagnetic switching valve 8a is de-energized (OFF), the air-receiving space 7pa becomes the low pressure target value (Pn), and the sack 5a expands the blood receiving space 7fa (direction toward the sensor 1a in FIG. 1a). ) Is inhaled (inhalation process).

A magnetized magnetic material (sheet-shaped ferrite permanent magnet) 2a is bonded to the center of the sack 5a, and a hole IC 1a is disposed directly above it. The hall IC 1a detects the magnetic field strength of the magnetic body 2a and outputs an electric signal indicating the magnetic field strength to the signal processing circuit 13 of the control device 12.
give to a.

The structure of the second pump 7b is the same as that of the first pump 7a. The first pump 7a of the second pump 7b
The symbol corresponding to the first pump 7a is denoted by a symbol in which "a" is replaced with "b".

The second pump 7b is compressed / expanded by turning on / off the second electromagnetic switching valve 8b. The detection signal of the hole IC 1b of the second pump 7b is given to the signal processing circuit 13b of the control device 12.

The signal processing circuits 13a and 13b convert the magnetic field strength signal into a distance signal (analog). That is, the sack 5 having the hole ICs 1a and 1b as a base point.
An analog signal indicating the distance or position of a and 5b is generated, and this is supplied to the A / D converter 17 via the input / output port 16. Position (distance) of sack 5a, 5b
However, it should be noted that the origin is the Hall ICs 1a and 1b, and the level of the analog signal is high when the sucks 5a and 5b are close to the contracted position, and the signal level is low when the sucks 5a and 5b are close to the expanded position.

The electric coils of the first electromagnetic switching valve 8a and the second electromagnetic switching valve 8b are connected to solenoid drivers 14a and 14b of the control device 12, respectively, and the drivers 14a and 14b are microprocessors (hereinafter referred to as CPU). ) 18, the electric coil is turned on (energized) / off (not energized).

The electric coils of the solenoid on-off valves 10P and 10N are connected to solenoid drivers 14c and 14d, respectively, and the drivers 14c and 14d are connected to CP.
The electric coils of the solenoid opening / closing valves 10P and 10N are turned on / off in accordance with instructions from U18.

Electric motor for driving the air pump 11p
11 m is connected to the motor driver 15, and the driver 15 responds to an instruction from the CPU 18 to generate an electric motor 11 m.
Turn on / off.

The pressure sensors 9ps and 9ns generate electric signals corresponding to the internal pressures of the accumulators 9P and 9N, and apply them to the signal processing circuits 13c and 13d. The signal processing circuits 13c and 13d convert the electric signal into an analog signal showing a level change having a linear relationship with the pressure, and through an input / output port 16 an A / D converter.
Give it to TA 17.

A system controller 19, a RAM 20 and a ROM 21 are connected to the CPU 18 of the controller 12.

An operation / display board 22 having a power switch, a key for inputting data, a two-dimensional display, a display lamp and a buzzer is connected to the control unit 12.

3 to 7 show the control operation of the CPU 18, and FIG. 8 shows the pump 7 appearing by this control operation.
The timing when high pressure (positive pressure) and negative pressure (negative pressure) are applied to a and 7b and the position change of (the magnetic body 2a of) the suck 5a of the pump 7a are shown.

Referring to FIG. 3, when the device is powered on and a predetermined voltage is applied to itself (step 1), CP
U18 clears internal registers, counters, timers, etc., and all output ports have standby signals (solenoid valve off,
Motor off) and the contraction position register Psa
(7a), Psb (7b), the standard value Ps is written, and expansion position registers Pea (7a) and Peb (7) are written.
Write the standard value Pe to the target flow rate register F
The standard value Fs for sa (7a) and Fsb (7b)
, And write A (7a
Write (monitor target) (step 2). Then, the two-dimensional display of the operation / display board 22 displays the input item, the numerical value set therein, and the guidance sentence prompting the input thereto (step 3). Numerical values and the like set as input items are as follows.

Contraction position-first pump "Psa: Ps", second pump "Psb: Ps" Expansion position-first pump "Pea: Pe", second pump "Peb: Pe" Target flow rate-first pump "Ps: Ps" Fsa: Fs "Second pump" Fsb: Fs "Monitor pump-" A / B: A "Ps, Pe, Fs, Ts are numbers. In addition to this, the next half-beat cycle is also displayed, but the input of this item is not accepted.

Half-beat cycle-First pump "Tsa: Ts" Second pump "Tsb: Ts" This Ts is the stroke Pe-Ps for the first and second pumps.
1 / of the pulse cycle required to obtain the flow rate Fs when driven by
It is a value of 2 and is calculated by the CPU 18 from the stroke Pe-Ps and the flow rate Fs.

The guidance text says, "・ If there is a change, place a cursor at the change and enter the number to be changed.-Start key when starting, stop key when stopping. Please press. " When there is a change input (contract position, expansion position, target flow rate or monitor pump), the CPU 18 reads the change input, changes the display to the input one, and updates the contents of the register as well (step 3A). Further, the half beat cycle corresponding to the changed value is calculated, and the contents of the half beat cycle register and the half beat cycle display are updated to the calculated values (step 3B). Then wait until the start key is pressed (steps 3A, 3B, 4, 3A, 3B, ...).

When the start key is pressed, the CPU 18
Energizes the electric motor 11m to drive the air pump 11p, and then turns on the electromagnetic switching valves 10P and 10N (open: flow). And pressure sensors 9ps and 9
The detected high pressure and the detected negative pressure of ns are detected by the A / D converter 17
And waits until the detected high pressure becomes equal to or higher than the content Pp of the target high voltage register Pp and the detected negative pressure becomes equal to or lower than the content Pn of the target low voltage register Pn. The pressure detected by the pressure sensor 9ps is P
When the pressure exceeds p, constant pressure control (pressure sensor 9p
When the detected pressure of s is read at a predetermined cycle, the electromagnetic on-off valve 10P is turned off when the detected pressure is Pp or more and turned on when the detected pressure is less than Pp), and when the detected pressure of the pressure sensor 9ns becomes Pn or less. , Constant pressure control (not shown) (the pressure detected by the pressure sensor 9 ns is read in a predetermined cycle, and when the detected pressure is Pn or less, the electromagnetic on-off valve 10N is turned off, and when it exceeds Pn, it is turned on)
Is started (step 5). At this point, the content Pp of the target high-voltage register Pp = Pps (reference high voltage: initial value determined by program) and the content Pn of target low-voltage register Pn = Pns (reference low voltage: initial value determined by program).

(1) Control of the first half cycle The CPU 18 controls the electromagnetic switching valve 8 connected to the first pump 7a.
a is turned on (pump 7a: contraction = discharge), the second pump 7 is turned on.
The electromagnetic switching valve 8b connected to b is turned off (pump 7b: expansion = intake) (step 6), the timer (program timer) is set to the time limit value Th-dt, and the timer is started (7). . Th is the content of the beat half cycle register Th,
dt is a time value defined by the program and is a value that is considerably smaller than Th.

The Th-dt timer has a time-over value (Th-
When the operation / display board 22 receives an input while waiting for the time dt to elapse (8), the input corresponding processing is performed. The input can be a stop input in addition to the numerical input in step 3A above. When there is a stop input, stop processing is performed. When a numerical value is input, the same processing as steps 3A and 3B is performed (34A, 35).
A). If there is no input, or if there is a numeric input and the processing is terminated, the Th-dt timer waits for time over (8). When the time is over, d of the dt time limit
Start t timer (9), monitor pump register A
It is checked whether the content of / B is A (specified by the first pump 7a) (10).

If the content of the monitor pump register A / B is A, the position detection signal of the hall IC 1a (sack 5a
Distance from the Hall IC) is read (11A), FIG.
Then, it is checked whether the detected position has reached the contracted position Ps (contents of the register Ps) (12
A), if it has reached, the content of the target high voltage register Pp is set to 1
Decrement (13A). Then, it waits for the time over of the dt timer (14A). When the detected position has not reached the contracted position Ps, the time-out of the dt timer is started.
After waiting for the time (15A), when the time is over, the position detection signal of the hall IC 1a is read again (16A). If the detected position has not reached the contracted position Ps, the contents of the target high voltage register Pp Clement (18A). this,
By adjusting the content of the target high-voltage register Pp, if the first pump 7a has finished contracting (reaching Ps) before the start of the contraction drive and before dt before the half-beat cycle Th, the content of the target high-voltage register Pp is smaller by one step. The value is updated to the value, and when the contraction is not yet finished when the half beat cycle Th has elapsed, the content of the target high voltage register Pp is updated to a value one step larger. Corresponding to this update, the pressure control of the high pressure accumulator 9P causes the pressure of the accumulator 9P to change to a low or high value.

When the content of the monitor pump register A / B is B, the position detection signal of the hall IC 1b (distance of the sack 5b from the hall IC) is read (11).
B), proceed to the flow of FIG. 5, and the detection position is the expansion position Pe.
It is checked whether (contents of the register Pe) is reached (12B), and if it is reached, the content of the target low voltage register Pn is incremented by 1 (13B). Then, it waits for the time over of the dt timer (14B). When the detected position has not reached the expanded position Pe, wait for the time over of the dt timer (15B), and when the time is over, the position detection signal of the hall IC 1b is read again (16B).
If the detected position has not reached the expansion position Pe, the content of the target low voltage register Pn is decremented by 1 (18B). By adjusting the contents of the target low-voltage register Pn, if the second pump 7b has completed expansion (reaching Pe) before the start of expansion driving dt before the half-beat cycle Th, the contents of the target low-voltage register Pn will be 1. The value is updated to a step larger value, and when the half-stroke cycle Th has elapsed and the inflation has not ended, the content of the target low pressure register Pn is updated to a value one step smaller. Corresponding to this renewal, the pressure control of the low pressure accumulator 9N described above causes the accumulator 9N
The pressure changes high or low.

(2) Control of second half cycle When the dt timer times out, the CPU 18 makes the first
The electromagnetic switching valve 8a connected to the pump 7a is turned off (pump 7
a: expansion = suction), the electromagnetic switching valve 8b connected to the second pump 7b is turned on (pump 7b: contraction = discharge) (step 19A in Fig. 4), and the timer is set to the time limit value Th-dt. The timer is started (20A).

Waiting for the Th-dt timer to time-over (21A), and if there is an input to the operation / display board 22 while waiting, the processing corresponding to the input is performed. When there is a stop input, stop processing is performed. When a numerical value is input, the same processing as steps 3A and 3B is performed (3
4B, 35B). If there is no input, or if there is a numeric input and the processing is terminated, the Th-dt timer waits for time over (21A). When the time is over, the dt timer for the dt time period is started (22A), and it is checked whether the contents of the monitor pump register A / B are A (the first pump 7a is designated) (23A).

When the content of the monitor pump register A / B is A, the position detection signal of the hall IC 1a (sack 5a
Distance from the Hall IC) is read (24A), FIG.
Then, it is checked whether the detected position has reached the expansion position Pe (content of the register Pe) (25
A), if it has reached, the content of the target low voltage register Pn is set to 1
Increment (26A). Then, it waits for the time over of the dt timer (27A). The detection position is the expansion position Pe
If the time has not yet reached, wait for the dt timer time over (28A), and when the time over is reached, the ho
The position detection signal of the IC 1a is read (29A), and if the detected position has not reached the expansion position Pe, the content of the target low pressure register Pn is decremented by 1 (31A). this,
By adjusting the content of the target low-voltage register Pn, if the first pump 7a has finished expanding (reaching Pe) before the start of expansion driving by dt before the half-beat cycle Th, the content of the target low-voltage register Pn is one step larger. The value is updated, and when the half-beat cycle Th has elapsed and the inflation has not ended, the content of the target low voltage register Pn is updated to a value that is one step smaller. Corresponding to this update, the pressure control of the low-pressure accumulator 9N changes the pressure of the accumulator 9N to high or low.

When the content of the monitor pump register A / B is B, the position detection signal of the hall IC 1b (distance of the sack 5b from the hall IC) is read (24).
B), proceed to the flow of FIG. 7, and the detection position is the contraction position Ps.
It is checked whether (contents of register Ps) has been reached (25B), and if it has reached, the contents of the target high voltage register Pp are decremented by 1 (26B). Then, it waits for the time over of the dt timer (27B). When the detected position has not reached the contracted position Ps, the time detection of the dt timer is waited (15B), and when the time is over, the position detection signal of the hall IC 1b is read again (28B).
If the detected position has not reached the contracted position Ps, the content of the target high voltage register Pp is incremented by 1 (31B).
By adjusting the contents of the target high-voltage register Pp, the second
When the pump 7b has completed contraction (reached Ps) from the start of contraction drive to dt before the half-beat cycle Th, the content of the target high-voltage register Ps is updated to a value smaller by one step and the half-beat cycle Th has elapsed. When the contraction is not yet completed, the content of the target high voltage register Pp is updated to a value one step larger. Corresponding to this update, the pressure control of the high pressure accumulator 9P causes the pressure of the accumulator 9P to change to a low or high value.

(3) Control of Third Half Cycle and Below The control of the odd half cycles thereafter, such as the third half cycle, the fifth half cycle, etc., is the same as the control of the first half cycle described above, and the fourth half cycle. , The sixth half cycle, etc., and the subsequent even-numbered half cycle control are the same as the above-described second half cycle control.

By repeating the above process, for example, when the first pump 7a is designated as a monitor (monitoring) (the contents of the monitor pump register A / B is A), the pump 7a is driven to contract. Immediately before the end of (solenoid valve 8a ON) (when the Th-dt timer time-overs),
When the sack 5a reaches the contraction end position (Ps),
Assuming that the pressure of the high pressure accumulator 9P is too high, the content of the target high pressure register Pp is updated to a value smaller by one. If the sack 5a has not reached the contraction end position (Ps) at the end of contraction drive of the pump 7a (when the dt timer has timed over), the pressure of the high pressure accumulator 9P is considered to be too low, and the target high pressure is assumed. The content of the register Pp is updated to one large value. As a result, the positive drive pressure (accumulator 9P) is adjusted so that the sack 5a reaches the contraction end position Ps within the time dt between the Th-dt time and the Th time immediately before the end of the half cycle Th of the contraction drive. Pressure) will be automatically adjusted. Expansion drive of the pump 7a (solenoid valve 8
Immediately before the end of (a off) (Th-dt timer is
If the sack 5a has reached the expansion end position (Pe), the pressure of the low-pressure accumulator 9N is too low (the absolute value of the negative pressure is too large), and the contents of the target low-pressure register Pn Is updated to a value larger by 1. Pump 7a
If the sack 5a does not reach the expansion end position (Pe) at the end of the expansion drive (when the dt timer timed over), the pressure of the low pressure accumulator 9N is too high (the negative pressure absolute value is (Too small), the content of the target low voltage register Pn is updated to a value smaller by one. As a result, the drive negative pressure (accumulator 9) is reached so that the sack 5a reaches the expansion end position Pe within the time dt between the Th-dt time and the Th time immediately before the end of the half cycle Th of the expansion drive.
N pressure) will be automatically adjusted.

When the second pump 7b is designated as a monitor (monitoring) (the content of the monitor pump register A / B is B), the hole Ic 1 for detecting the position of the suck 5b is detected.
Using the detection signal of b, the above-mentioned target high / low pressure resistor P
The values of p and Pn are similarly changed. In this case,
Th just before the end of the half cycle Th of contraction drive of the pump 7b
-The positive drive pressure (pressure of the accumulator 9P) is automatically adjusted so that the sack 5b reaches the contraction end position Ps within the time period dt between the -dt time and the Th time, and a half cycle of expansion drive is performed. Th-dt time immediately before the end of Th
The driving negative pressure (pressure of the accumulator 9N) is automatically adjusted so that the suck 5b reaches the expansion end position Pe within the time dt between the times.

Therefore, the flow rates delivered by the pumps 7a and 7b are substantially constant values determined by the set contraction position Ps, expansion position Pe, and half-beat period Th, so that when the required flow rate is given, Ps and Pe are given. And the half-beat period Th is calculated from Ps and Pe and the required flow rate, the pumping of the required flow rate is realized. This half cycle T
The CPU 18 calculates h in step 3B of FIG. When the required flow rate and the beat cycle are given, the required Ps and Pe may be calculated based on these and set in the contraction position register Ps and the expansion position register Pe.

Although two pumps are used in the above embodiment, the number of pumps may be three or more. In the case of three pumps, the second pump is driven with the same pulsation cycle with a delay of 2Th / 3 with respect to the first pump, and the third pump has the same pulsation with a delay of 4Th / 3 with respect to the first pump. It may be driven in a cycle. In the case of four pieces, it is sufficient to drive in the same pulsation cycle with a phase delay of Th / 2 sequentially.

Further, although the above-mentioned embodiment is a pumping device for sucking and discharging living blood, the present invention is not limited to this, and is similarly applied to other uses where a substantially constant flow rate is required. sell.

[0046]

As described above, according to the pumping device of the present invention, the flow rate delivered by the pump is set at the set contraction position P.
s, the expansion position Pe, and the half-beat cycle Th are substantially constant values. When the required flow rate is given, it is sufficient to set the half-beat cycle Th and / or the contraction position Ps and the expansion position Pe which bring about the required flow rate, and the flow rate can be adjusted by these.

[Brief description of drawings]

FIG. 1 is a drawing showing an embodiment of the present invention and is a cross-sectional view showing a pump and an electromagnetic switching valve connected thereto.

FIG. 2 is a block diagram showing an electric device or the like for controlling pumping, which is connected to the solenoid valve or the like shown in FIG.

FIG. 3 is a flowchart showing a control operation of the CPU 18 shown in FIG.

4 is a flowchart showing a control operation of the CPU 18 shown in FIG.

5 is a flowchart showing a control operation of the CPU 18 shown in FIG.

FIG. 6 is a flowchart showing a control operation of the CPU 18 shown in FIG.

FIG. 7 is a flowchart showing a control operation of the CPU 18 shown in FIG.

8 is a time chart showing the switching of pressures applied to the pumps 7a and 7b shown in FIG. 1 and the position of the magnetic body 2a fixed to the suck 5a of the pump 7a.

[Explanation of symbols]

1a, 1b: Hall IC 2a, 2
b: Magnetic substance 3a, 3b, 4a, 4b: Ball of check valve 5a, 5
b: sack 6a, 6b: air port 7a, 7
b: Pump 7fa, 7fb: Blood receiving space 7pa, 7
pb: Working fluid chamber 8a, 8b: Electromagnetic switching valve 9P: High pressure accumulator 9N: Low pressure accumulator 9ps, 9
ns: Pressure sensor 10P, 10N: Electromagnetic on-off valve 11p: Air-pump 11m: Electric motor 12: Control device 22: Operation / display board 23: Blood receiving port 24: Fluid delivery port

Claims (1)

[Claims] 1. A fluid receiving space and a working fluid space are divided,
A pumping member that can reciprocate in the direction of contracting / expanding the fluid receiving space, and is inserted between the fluid receiving port and the fluid receiving space to allow the fluid to flow from the former to the latter and prevent the fluid to flow in the opposite direction. And a second check valve that is interposed between the fluid outlet and the fluid receiving space and that allows the fluid to flow from the latter to the former and blocks the fluid in the reverse direction. A plurality of m pumps; a detecting means for detecting the end of discharge and the end of suction of at least one of the plurality of m pumps; a high pressure fluid source; a target for which the pressure of the high pressure fluid source is designated. High pressure control means for setting high pressure; low pressure fluid source; low pressure control means for setting pressure of the low pressure fluid source to a designated target low pressure; working fluid spaces of the plurality of pumps, high pressure fluid source and low pressure fluid Switching means selectively connected to the source; Means for pulsating the plurality of pumps with a phase difference of 1 / m of the pulsation cycle, and energizing the switching means so as to inhale from the discharge of the pump to be detected by the detecting means. The target high pressure is updated to a low value in response to the detection of the end of discharge by the detection means before the switching timing to the target high pressure, and the target high pressure in response to the non-detection of the end of discharge of the detection means at the switching timing. Is updated to a higher value, and the target low pressure is updated to a higher value in response to the detection of the end of suction of the detection means before the timing of switching from the suction to the discharge of the detection target pump of the detection means, and A fluid feed pumping device comprising: flow control means for updating the target low pressure to a low value in response to non-detection of the end of inhalation of the detection means.