JPH1080474A - Blood processing method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly cancel pressure limit and to evade exessive pressure increase due to the quick increase in a load by quickly reducing a pump flow rate when pressure to be monitored deviates a limit value and pressure limit occurs and recovering the pump flow rate after cancelling pressure limit in accordance with a prescribed speed increasing quantity. SOLUTION: The operation of a blood pump is controlled by monitoring blood taking pressure P1, vein pressure P2 and plasma separator difference pressure detected by a pressure detector and, at the same time, permitting it not to exceed these kinds of limit pressure. When pressure deviates the limit value and pressure limit is received, that is, when blood taking pressure P1 becomes lower than a min. value, vein pressure P2 exceeds a max. value or plasma separator difference pressure exceeds the max. value, the flow rate of the blood pump is quickly reduced by the speed decreasing quantity being 300ml/min./min., for example, and pressure limit is released. When pressure limit is released, the flow rate of the blood pump is increased by the proportion of the normal speed increading quantity and a target blood flow rate is recovered towards 100ml/min., for example.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method and apparatus for removing impurities and harmful substances and replacing specific components with blood.

[0002]

2. Description of the Related Art As a method of appropriately treating blood for the purpose of treatment, a method of separating plasma from blood and adsorbing and removing unnecessary and harmful substances in plasma from the separated plasma by an adsorption column, Conventionally known are a plasma exchange method in which replacement is performed with a replacement fluid, a double filtration method in which high molecular weight components in plasma are removed by double filtration, and an artificial dialysis method in which blood is brought into contact with a semipermeable membrane.

A blood processing apparatus for performing such blood processing generally includes a blood collection circuit for taking blood into a circuit by a blood pump, a blood processing circuit for appropriately processing blood, and a blood return circuit for returning processed blood. Are connected in series, and a plurality of pressure detectors and a plurality of valves are provided in important parts of the circuit in addition to a heparin injector, a filter, a heater, a bubble detector, and the like. If the apparatus separates and processes plasma from blood, the processing circuit further includes a plasma separator, a plasma pump, a blood leak detector, an adsorber, a secondary filter, and the like.

[0004] The blood processing apparatus thus configured is usually provided with control means for controlling the operation of the pump and the opening and closing of the valve, and is designed so that the apparatus itself can automatically operate the blood processing.

[0005]

When an abnormality occurs in the pressure in the circuit or the equipment during use of the blood processing apparatus, it is necessary to appropriately control the operation state of the pump in accordance with the nature of the abnormality. For example, Japanese Patent Publication No. 2-28981 and Japanese Patent Publication No. 5-50
No. 304 discloses that in a blood processing apparatus, when clogging occurs in a blood introduction part during processing and the primary side flow path to the pump becomes a large negative pressure, the rotation speeds of the first and second pumps are increased. It is stated that these flow rates are kept constant to avoid an increase in negative pressure.

However, the technology described in the above-mentioned prior application only deals with negative pressure in the primary flow path of the pump due to clogging in the blood introduction part, and also controls the pump during other abnormal situations and abnormal recovery. Was not disclosed.

[0007]

SUMMARY OF THE INVENTION The present invention provides excellent safety by appropriately controlling the operation state of a pump at the start of blood processing, at the time of occurrence of an abnormality during the processing, and at the time of recovery from an abnormality. Another object of the present invention is to provide a technique for performing efficient blood treatment.

[0008] The blood processing apparatus used in the present invention is a blood collection circuit for taking blood into a circuit by a blood pump, a blood processing circuit for performing predetermined processing on the taken blood, and returning the blood subjected to the predetermined processing. The blood return circuit includes a blood detector, a blood processing circuit, and a blood detector. A pressure detector is provided at an appropriate position in the blood return circuit, and control means for controlling the operation of the blood pump is provided. The present invention is characterized in that the following processing steps are performed by the blood processing apparatus configured as described above.

(1) At the start of the process, after the operation of the blood pump is started, the blood pump increases the flow rate at a preset normal rate until the blood flow reaches a predetermined target blood flow rate. Alternatively, the flow rate may be set to increase at least in two stages of the preset initial speed increase amount and the normal speed increase amount. (2) After the flow rate of the blood pump has reached the target blood flow rate, the operation is controlled so as to maintain the target blood flow rate. (3) When the pressure values detected by the predetermined pressure detectors or the calculated values based on these pressure values deviate from the limit values and are subjected to the pressure restriction, the flow rate of the blood pump is reduced by a predetermined deceleration amount. (4) When the pressure restriction is released, the flow rate of the blood pump is increased at the normal speed increasing amount, and the blood pump is restored toward the target blood flow rate.

Further, the following processing method can be added. (5) If an abnormality other than the pressure limit occurs during the operation of the blood pump, the flow rate of the blood pump is reduced by a predetermined deceleration amount, and then maintained at a standby flow rate that does not exceed a preset limit value. .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The blood treatment method to which the present invention is applied is not particularly limited, and may be any of blood treatments such as an adsorption removal method, a plasma exchange method, a double filtration method and an artificial dialysis method. It is also feasible.

Here, an embodiment of the present invention will be described by taking as an example a case in which plasma is separated from blood and then applied to blood treatment by adsorption in which cholesterol is removed from the separated plasma by an adsorber.

FIG. 1 shows an example of a blood processing apparatus used for blood processing by the above-mentioned adsorption. This blood processing device is a blood collection circuit for taking blood into the circuit by a blood pump and sending it to the plasma separator. The blood plasma separated from the blood by the plasma separator is guided to the adsorber by the plasma pump and unnecessary from the plasma. A cholesterol-removing circuit, and a blood-return circuit that combines the plasma after the treatment with the blood passing through the plasma separator and returns the blood.

The main parts of the circuit are drip chambers D1, D2, D4, D6, D7 provided with the pressure detector P3 or the pressure detectors P1, P2, P4, P6, P7, and for controlling the flow path. Valves V6, V7, V9, V12,
V13, V14, and V15 are provided, and further, a heparin injector for preventing blood coagulation, a blood leak detector for detecting blood leak in plasma flowing out of the plasma separator, and a prescribed blood return. A heater for warming to a temperature, an air bubble detector for detecting the incorporation of air bubbles into the returned blood, and the like are provided.

The operation of the blood pump and the plasma pump, and the opening and closing operations of the valves are performed based on detection signals from these devices and pressure detectors, etc., based on control means including a CPU, a blood flow setting device, and a plasma flow rate setting device. Controlled by the ratio setter.

The valve is controlled to open and close in conjunction with the pump, and automatically switches the flow path for each process. That is, a preparatory step for assembling the circuit and washing with a physiological saline solution before starting the processing, a step of introducing blood into the circuit and performing a plasma treatment by the adsorber, a step of collecting blood remaining in the circuit after the processing, and the like. At the time of execution, the control means operates the opening and closing of the valve so as to form a flow path corresponding to each step.

An outline of a blood processing method using the blood processing apparatus will be described. In the following description, the pressures measured by the pressure detectors P1, P2,.
1, 2, and so on.

The outline of the blood processing step is as follows. Usually, prior to performing the blood treatment, the circuit is assembled and the inside of the circuit is washed with a physiological saline solution. After the necessary preparation steps are completed, the operation of the blood pump is started, blood is taken into the circuit from the blood collection end of the blood collection circuit, and is sent to the plasma separator. The plasma separated from the blood by the plasma separator flows through the plasma circuit by the plasma pump and is guided to the adsorber.
Then, while passing through the adsorber, the plasma comes into contact with the adsorbent filled in the adsorber, whereby unnecessary cholesterol is removed from the plasma. The treated plasma flowing out of the adsorber merges with the blood passing through the plasma separator,
Returned through the blood return circuit. When the required processing is completed in this way, physiological saline is introduced into the circuit,
Collect and return blood and plasma remaining in the circuit.

In the blood processing step, the operation of the blood pump includes the blood pressure collection P1, the venous pressure P7, the plasma separator differential pressure ΔP
While monitoring the value of 2/6 (= P2-P6), control is performed so as not to exceed these limit values. After the start of the operation, if the pressure is not restricted, the flow rate Q of the blood pump
B is increased by a preset initial speed increase amount Vb ₀ until the integrated flow rate reaches a predetermined value. Usually, the integrated flow rate value is set substantially equal to the combined capacity of the blood collection circuit and the plasma separator.

When the integrated blood flow reaches a predetermined value,
The flow rate increase rate of the blood pump is switched to the normal speed increase amount Vb ₁ to reach the target blood flow rate QBs. After the flow reaches QBs, the operation of the blood pump is controlled so as to maintain the target blood flow.

The initial speed increase Vb ₀ is set to a value lower than the normal speed increase Vb _{1 in} order to prevent a sudden load from being applied to the processing equipment such as the plasma separator to cause an excessive pressure rise. Is common. However according to the processing conditions, it can be appropriately changed to a magnitude relation between the initial acceleration amount Vb ₀ and the normal acceleration amount Vb ₁ opposite.

When the pressures P1, P2, and ΔP2 / 6 monitored by the pressure detector deviate from the limit value and the pressure is limited, the blood pump flow rate is reduced by a predetermined deceleration amount V.
decrease in b _2. The value of the deceleration amount Vb ₂ is set to a sufficiently large value so as to quickly released the pressure limit. If the pressure limit is released to increase the flow rate of the blood pump in the normal acceleration amount Vb _1, to restore the target blood flow QBS.

As described above, according to the present invention, when the pressure is limited, the pump flow rate is reduced by a relatively large deceleration amount, so that it is possible to quickly escape from the abnormal pressure state. Gently increases, it is possible to avoid an excessive increase in pressure due to a sudden increase in load, so that a state in which the operation of the pump is not restricted can be maintained for a long time.

In a state where the blood pump is controlled to maintain the target blood flow rate QBs, an abnormality other than the pressure limitation, for example, an abnormality in the pressure value of another pressure detector,
If the operation abnormality of the valve occurs, the flow momentarily reduced by a large deceleration amount Vb ₃ a blood pump, maintains the stand flow QBa until abnormality is restored. The value of the standby flow rate QBa is set to a low speed such that blood does not coagulate in the circuit, with a predetermined limit value as an upper limit.

FIG. 2 summarizes the above-described pump flow rate control method.

The above description is directed to the case where the present invention is applied to blood treatment for adsorbing and removing undesired substances from plasma using an adsorber. Other than this, double filtration of plasma, plasma exchange, artificial dialysis, etc. When the present invention is applied, the control method of the blood pump may be appropriately changed in accordance with each blood processing embodiment.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of setting conditions when the blood processing according to the present invention is executed by the blood processing apparatus of FIG. 1 will be described below.

Immediately after the operation of the blood pump is started, the flow rate is set to 20.
It is increased by an initial speed increase amount Vb ₀ appropriately set in a range of 100 ml / min / min. When the integrated flow rate of blood reaches 300 ml, which is substantially equal to the total capacity of the blood collection circuit and the plasma separator, the flow rate QB is set to a normal acceleration Vb ₁ appropriately set in the range of 20 to 150 ml / min / min. To reach the target blood flow QBs = 100 ml / min. Normally, it sets the normal acceleration amount Vb ₁ to a value greater than the initial acceleration amount Vb _0. When the flow rate QB reaches the target blood flow rate QBs, the operation of the blood pump is controlled so as to maintain the flow rate.

The operation of the blood pump depends on the blood pressure P1, the venous pressure P2, and the plasma separator differential pressure ΔP2 /
6 while monitoring these limits. When the pressure deviates from the limit value and is subjected to the pressure limit, that is, whether the blood pressure P1 falls below the lower limit value,
When the venous pressure P2 exceeds the upper limit or the plasma separator differential pressure ΔP2 / 6 exceeds the upper limit, the flow rate QB of the blood pump is rapidly reduced at a deceleration rate of Vb ₂ = 300 ml / min / min. And release the pressure restriction. If the pressure limit is canceled, the blood pump flow rate QB is increased at a rate of the normal acceleration amount Vb _1, the target blood flow QBS (= 100 ml /
Minutes).

If there is no abnormality in the blood pump and an abnormality other than the above-mentioned pressure limit (for example, an abnormality in a valve) occurs, the blood pump is instantaneously decelerated at an extremely large deceleration Vb ₃ and the upper limit is 50 ml / min. The blood pump is controlled so that the standby flow rate QBa set by the blood flow rate setting device is obtained. When the abnormality is eliminated, the blood pump flow rate QB is restored toward the target blood flow rate QBs. The execution procedure is as described above.

On the other hand, the plasma pump is stopped after the operation of the blood pump is started while the blood pump flow rate QB is less than 15 ml / min. Blood pump flow QB is 15ml
/ Min, the pressure difference TMP [=
(P2 + P6) / 2-P3] and adsorber differential pressure ΔP4 / 6
The operation of the plasma pump is started while monitoring (= P4-P6). Until the integrated flow rate of plasma becomes 50 ml which is almost equal to the volume of plasma on the secondary side in the plasma separator, the plasma pump flow rate QP is increased by the initial speed increase Vp ₀ set in the range of 10 to 60 ml / min / min. Let it. Integrated flow rate is 50
ml, the plasma pump flow rate QP
0 ml / min / in min range is increased in the normal acceleration amount Vp ₁ is set to reach the target plasma flow QPs. In addition,
In order to moderate the burden on the equipment,
Towards the normal acceleration amount Vp ₁ is set larger than the initial acceleration amount Vp _0.

After reaching the target plasma flow rate QPs, the plasma pump is controlled momentarily so as to maintain this.

The target plasma flow rate QPs is obtained by adding the blood flow rate QB of the blood pump, the plasma flow rate coefficient K preset by the plasma flow rate setting device, and the separation membrane differential pressure T in the plasma separator.
A value obtained by multiplying MP [= (P2 + P6) / 2−P3] by a coefficient R1 defined below, that is, QPs = K ·
It is given by R1 · QB.

R1 = 1.0- (TMP / TMP upper limit value)
* (1.0-r) In the above equation, r is a differential pressure upper limit coefficient, and 0.0 ≦ r <
In the range of 1.00, it is appropriately set according to the state of clogging of the separation membrane. Depending on the properties of the blood and the quality of the separation membrane, the separation membrane may be easily clogged. If it is empirically known that clogging is likely to occur, the value of r is set lower. Conversely, when it is empirically known that there is no risk of clogging, the value of r may be set higher.

The plasma flow ratio coefficient K is a value set by the plasma flow ratio setting device in consideration of the performance of the plasma separator and the properties of blood, and is generally set in the range of 0.2 to 0.4. , Usually in the range of 0.25 to 0.35.

The operation of the plasma pump depends on the differential pressure of the separation membrane TMP of the plasma separator and the differential pressure of the adsorber ΔP4 / 6 (= P4−P
It is controlled while monitoring the value of 6). When these pressures deviate from the limit values, the plasma pump flow rate QP is rapidly reduced at a predetermined deceleration Vp ₂ (for example, 140 ml / min / min). When the pressure restriction is released due to the decrease in the flow rate, the flow rate QP of the plasma pump is again increased by the normal speed increasing amount Vp.
It is increased by ₁ and is restored toward the target plasma flow rate QPs.

The lower limit of the blood pressure P1 and the venous pressure P
2, the upper limit of the plasma separator differential pressure ΔP2 / 6, the upper limit of the separation membrane differential pressure TMP, and the upper limit of the adsorber differential ΔP4 / 6 are all set on the inner ring at about 20 mmHg lower than the alarm value. Is secured.

Incidentally, the plasma pump is not operated independently of the blood pump, but is controlled in conjunction with the blood pump. When there is no abnormality in the plasma pump and it becomes necessary to reduce the flow rate QB of the blood pump due to the pressure limitation, the flow rate QP of the plasma pump is also reduced. In this case, QP = K · R1
-Control so that the relationship of QB is always maintained. When the blood pump is set to the standby flow rate QBa due to an abnormality other than the pressure limitation (valve abnormality or the like), the plasma pump is stopped or the standby flow rate QPa = K derived from the above relational expression.
・ It is R1 · QBa.

When the flow rate QP of the blood pump falls below a certain value (for example, 15 ml / min), the plasma pump is set to stop.

The procedure for restoring the plasma pump flow rate QP when the pressure limitation and other abnormalities are resolved is the same as described above.

[0041]

According to the present invention, when performing a blood treatment,
If the pressure monitored by the pressure detector deviates from the limit value and a pressure limit occurs, the pump flow rate is set to decrease rapidly, so that the pressure limit is quickly released and normal blood processing is performed. Can be continued promptly.
Then, the recovery of the pump flow rate after the pressure limitation is canceled is performed according to the preset speed increase amount.
Excessive pressure rise due to a sudden increase in load can be avoided.

If the pump flow rate is set to be increased in two stages at the time of blood introduction immediately after the start of operation of the processing apparatus, a sudden load is not applied to the apparatus, and therefore the pressure rises. Instead, it is possible to quickly reach the target flow rate.

Further, when an abnormality other than the pressure limit occurs, the pump is instantaneously decelerated and the standby flow rate is controlled so as not to exceed a preset upper limit value. The blood can be prevented from coagulating in the circuit while maintaining the performance.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a circuit configuration of a blood processing apparatus according to the present invention.

FIG. 2 is a graph showing a control situation of a pump according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasushi Hamani 1-15-34, Kamikoshien, Nishinomiya-shi, Hyogo (72) Inventor Nozumi Takao 2-9-132 Nakamachi, Musashino-shi, Tokyo Inside Yokogawa Electric Corporation (72) Inventor Masataka Narisada 2-9-132 Nakamachi, Musashino City, Tokyo Inside Yokogawa Electric Corporation

Claims (6)

[Claims] 1. A blood pump, which is provided in a blood collection circuit, sends blood taken into a blood processing circuit, performs predetermined processing on the blood in the blood processing circuit, and returns the processed blood through a blood return circuit. In the blood processing method, a pressure detector is provided at an appropriate position of a blood collection circuit, a blood processing circuit, and a blood return circuit, and the flow rate of the blood pump is set to a predetermined normal rate from the start of operation until a predetermined target blood flow rate is reached. After reaching the target blood flow rate, the operation of the blood pump is controlled so as to maintain the target blood flow rate, and a pressure value detected by a predetermined pressure detector or a calculation based on these pressure values If the value deviates from the limit value and is subjected to a pressure limit, the flow rate of the blood pump is reduced by a predetermined deceleration amount, and if the pressure limit is released, the flow rate of the blood pump is reduced to the normal speed increasing amount. Increase in Blood processing method for causing to recover toward the target blood flow rate is. 2. The method according to claim 1, wherein the flow rate of the blood pump is increased in at least two stages of a preset initial speed increase amount and a normal speed increase amount from the start of operation until the target blood flow rate is reached. Item 7. The blood processing method according to Item 1. 3. When an abnormality other than the pressure limitation occurs during the operation of the blood pump, the flow rate of the blood pump is reduced by a predetermined deceleration amount, and then a standby state in which a preset limit value is not exceeded is set. 3. The blood processing method according to claim 1, wherein control is performed to maintain the flow rate. 4. A blood circuit comprising a blood collection circuit for taking blood into a circuit by a blood pump, a blood processing circuit for performing predetermined processing on the taken blood, and a blood return circuit for returning the blood subjected to the predetermined processing. In the processing device, control means for controlling the operation of the blood pump, and a pressure detector disposed at an appropriate position in the blood collection circuit / blood processing circuit / blood return circuit are provided. Until the target blood flow rate is reached, the flow rate of the blood pump is increased at a preset normal acceleration rate, and after reaching the target blood flow rate, the blood pump is operated to maintain the target blood flow rate, When the pressure value detected by the predetermined pressure detector or the calculated value based on these pressure values deviates from the limit value and is subjected to pressure limitation, the flow rate of the blood pump is reduced by a predetermined deceleration amount, and the pressure control is performed. Blood processing apparatus characterized by but is set the flow rate of the blood pump if it is released by increasing at the normal acceleration amount so as to recover toward the target blood flow. 5. The control means controls the flow rate of the blood pump from the start of operation until the target blood flow rate is reached.
5. The blood processing apparatus according to claim 4, wherein the blood processing apparatus is set to increase at least in two stages of an initial speed increase amount and a normal speed increase amount set in advance. 6. The control means, when an abnormality other than the pressure limitation occurs during the operation of the blood pump, reduces the flow rate of the blood pump by a predetermined deceleration amount, and then sets a preset limit value. The blood processing apparatus according to claim 4 or 5, wherein the blood processing apparatus is set so as to maintain a standby flow rate that does not exceed the pressure.