JPH0464705B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a device that does not cause damage to blood even when used for a long period of time and is capable of safely performing extracorporeal circulation, especially for providing respiratory support safely and completely. The present invention relates to an extracorporeal blood circulation device with an artificial lung function that can be implemented. The present invention will be described below as an extracorporeal blood circulation device equipped with an artificial lung function. It can also be applied to circulation devices, etc.

(Prior art) In a conventional device with this kind of oxygenator function, there is a venous blood removal circuit with a blood pump interposed via a blood reservoir on the inflow side of the oxygenator, and an arterial side blood removal circuit on the outflow side. Generally, a method is adopted in which a blood pump is connected to a blood supply circuit and a blood supply pump is used to perform extracorporeal circulation so that the amount of blood circulating in the body is constant during cardiac surgery or the like.

However, with such conventional devices, during surgery, blood is collected into a blood reservoir that stores surplus extracorporeal circulating blood that increases due to blood removal from the heart and lungs, and is usually performed by removing blood by using a drop between the patient and the blood reservoir. This drop is over 1m. For this reason, it is necessary to raise the patient to a high position and perform the surgery while the surgeon stands on a table, which makes the surgery inconvenient, and the circuit required for blood collection is inevitably long, which increases the priming volume. It was not possible to avoid the situation where the size of the Therefore, there was a problem that conventional devices could not be applied to neonates and children with small amounts of whole blood. In addition, roller-type or finger-type pumps are generally used as blood pumps, but when using these pumps, the blood circuit is squeezed and squeezed by the rollers or fingers, which can cause blood damage, especially a decrease in the number of platelets and hemolysis. There was a problem of influence. For this purpose, instead of a roller or finger pump, a flexible bag is housed in a non-flexible housing.
Various types of pumps have been developed that use air pressure to expand and deflate the pump. However, all of these are merely pulsating pumps that replace conventional pumps, and do not significantly contribute to reducing the priming volume.

(Problems to be Solved by the Invention) An object of the present invention is to provide an extracorporeal blood circulation device that shortens the blood circuit to reduce the priming volume and can be applied to newborns and children with a small amount of whole blood.

A further object of the present invention is to provide an extracorporeal blood circulation system that does not require dangerous equipment such as a high bed or a step stool for the operator, and is convenient for operations and patient monitoring.

The object of the present invention is to provide a safe extracorporeal blood circulation device that does not cause damage to blood even when used for a long time.

(Means for Solving the Problems) The present invention is a pump that accommodates a flexible blood reservoir in a non-flexible housing, expands and contracts the blood reservoir using liquid pressure, and repeats blood removal and blood supply. In an extracorporeal blood circulation device in which a blood removal circuit is connected to an inflow side of an artificial organ, and a blood feeding circuit is connected to an outflow side of the artificial organ, the non-flexible housing has a flexible liquid reservoir. The liquid circulation circuit is connected such that the liquid reservoir has a height difference to the housing, and the blood inlet side and blood outlet side of the pump device of the blood removal circuit and the liquid outlet side of the pump device of the liquid circulation circuit are connected to each other such that the liquid reservoir has a head difference with the housing. expansion of the blood reservoir,
Valve V ₂ controlled in conjunction with a device that detects contraction,
V ₁ and V ₃ are provided, and a liquid feeding means is provided on the liquid outlet side of the liquid reservoir in the liquid circulation circuit to control in conjunction with the detection device, and when the detection device detects expansion of the liquid reservoir, the valve V ₁ is opened. and closes the valves V ₂ and V ₃ , drives the liquid feeding means to send out the blood in the blood reservoir, and when the detection device detects contraction of the blood reservoir, closes the valve V ₁ ,
Open valves V ₂ and V ₃ , stop the liquid feeding means,
A blood extracorporeal circulation device characterized in that it is configured to collect blood in a blood reservoir.

(Embodiment) Next, an embodiment of the extracorporeal blood circulation apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system diagram of a double-needle type device using two catheters, in which blood is pumped from a vein or artery of a patient (not shown) to an alternating pump device ₁ provided in a blood removal circuit L1. The artificial lung 2 passes through the blood reservoir 4, which expands and contracts to perform blood removal and blood supply.
The purified blood that has been supplied to the patient and then subjected to gas exchange in the oxygenator is returned to the patient via the drip chamber 3 provided in the blood supply circuit _L2 . Above blood removal circuit L ₁
A co-injection line for heparin injection and degassing may also be provided.

The expansion and contraction of the blood reservoir 4 is carried out by the housing 5.
This can be done by connecting a liquid circulation circuit _L3 with a flexible liquid reservoir 6 interposed therebetween, and supplying or discharging the liquid sealed in the circuit to the closed space 9. For this reason, the blood removal circuit
Valves V ₁ , V ₂ , and V 3 to open and close each circuit as appropriate are installed on the blood inlet and blood outlet sides of the pump device in L ₁ and the liquid outlet side of the pump device in L _{3 ,} and in a closed space in the liquid circulation circuit. A means 7 for feeding the liquid is provided. Furthermore, if a heating device is provided in the liquid circulation circuit _L3 , the blood can be indirectly heated within the pump device, and a drop in the temperature of the extracorporeally circulating blood can be prevented.

The pump device 1 surrounds a blood reservoir 4 made of a flexible material capable of expanding and contracting, which constitutes a part of the blood removal circuit _L1 , with a housing 5 having sufficient inflexibility compared to the flexible material. A sealed space 9 is formed between the blood reservoir 4 and the housing 5, and blood removal and blood transfer are performed by a pump action that pressurizes or depressurizes the sealed space to expand and contract the blood reservoir. The blood reservoir 4 has the shape of a bag or tube made of silicone rubber, polyurethane, soft vinyl chloride, polyether, natural or synthetic rubber with good flexibility. The volume of this blood reservoir when expanded can be determined as appropriate depending on the treatment purpose or the patient's condition, but it is usually the same size as the volume of cardiac output per stroke, for example, 10 to 16 ml for children and 50 to 80 ml for adults. are preferably used. The housing surrounding the blood reservoir may be made of non-flexible polypropylene, polyethylene, rigid PVC, polycarbonate, acrylic, polystyrene, metal, or the like. Preferably, transparent plastic is used to observe the operating status of the blood reservoir contained within the housing. Further, the housing may be a reusable structure in which the blood reservoir is liquid-tightly housed during use as a detachable two-part structure, or a disposable type in which the housing is integrated with the blood reservoir. An inlet 10 for injecting liquid into the liquid circulation circuit is provided at the upper part of the housing.

As the artificial lung 2, a coil type, a laminated type, or a hollow fiber type can be used. In particular, a hollow fiber type is preferably used because it is easy to produce and can be downsized. As the separation membrane accommodated in such an oxygenator, homogeneous membranes made of silicone polymers and porous membranes made of polypropylene, polyethylene, polytetrafluoroethylene, polysulfone, etc. can be used. Among them, recently developed porous membranes such as polysulfone can be used. A composite membrane in which one surface of the plasma membrane is coated with a thin silicone film is suitable for use in an oxygenator because there is no leakage of plasma components.

In order to exchange oxygenators during blood extracorporeal circulation treatment, it is preferable to connect a plurality of oxygenators in parallel. At this time, if oxygenators with different membrane areas are connected, the membrane area can be reduced appropriately according to the patient's condition to provide optimal treatment.

The liquid reservoir 6, which is provided integrally with the liquid circulation circuit _L3 connected to the housing 4, is made of a flexible material that can expand and contract like the blood reservoir 4, and the volume when expanded can be adjusted to any desired size. However, it is usually preferable to use the same one as the blood reservoir 4. In the present invention, it is important to arrange the liquid reservoir at a lower position than the pump device so as to create a head difference between the liquid reservoir and the pump device 1, and due to this head difference, the liquid pressurized in the closed space is directed to the liquid reservoir. This creates a negative pressure in the sealed space and draws blood into the blood reservoir. This head is usually 90-100 cm.

A pump can be used as the liquid feeding means 7 provided on the liquid outlet side of the liquid reservoir 6. Among them, it is preferable to use a positive displacement pump such as a roller pump or a plunger pump that can maintain a pressurized state when the operation is stopped. In particular, a multi-roller type roller pump with less pulsation during pressurization is practical. 1st
In the figure, a roller pump whose drive is controlled by interlocking control with a detection device 8, which will be described later, is used. The liquid supplied by this pressurizing means is preferably degassed sterile water, physiological saline, glucose solution, or the like, which poses no danger even if it leaks to the blood side.

Pinch valves are normally used as the valves V ₁ , V ₂ , and V ₃ that open and close the blood removal circuit L ₁ and the liquid circulation circuit L ₃ .

The device 8 for detecting expansion and contraction of the blood reservoir 4 includes a method of detecting the amount of expansion and contraction of the liquid reservoir 6 which expands and contracts in proportion to the blood reservoir using two adjacent switches, and a pressure change in a sealed space within the housing. , a method of detecting the weight of the liquid reservoir or pump device using a scale, or a method of detecting expansion and contraction of the blood reservoir using the above-mentioned means and controlling the next operation using a timer. Among these methods, a method of detecting the amount of expansion and contraction of the liquid reservoir using a proximity switch such as a capacitance type or an optical type is preferred because it is simple and highly accurate. FIG. 1 shows an example using two proximity switches 8a and 8b for detecting expansion and contraction of a liquid reservoir.

The detection device 8, pinch valves V ₁ , V ₂ , V ₃ ,
The liquid feeding means 7 is configured to be electrically controllable, so that the entire extracorporeal blood circulation apparatus can be automatically controlled.

FIG. 2 shows an example of a single-needle type extracorporeal blood circulation device using a double-lumen catheter 11. A branch pipe 12 is provided in the catheter 11, and a pump device 1 is interposed between one of the branch pipes and the inflow side of the oxygenator. The other branch pipe and the outflow side of the oxygenator ₂ are connected to the blood supply circuit _L2 . In this case, in order to prevent the purified blood from flowing back into the blood removal circuit _L1 , the blood supply circuit _L2 is provided with a pinch valve _V4 which is controlled in conjunction with the proximity switch 8. This valve V ₄ is opened during the blood feeding process,
It is configured to be closed during the cerebral blood process.

FIG. 3 shows an example in which a constant speed pump is used as the liquid feeding means 7, and in this case, a bypass circuit L is provided in which a valve V ₇ , which is switched and controlled in conjunction with the detection device 8, is interposed in the liquid circulation circuit L ₃ . ₄ are provided.

Since this valve V ₇ is opened together with the valve V ₃ during blood removal, the liquid circulates through the bypass circuit L ₄ without being supplied to the closed space 9, and during this time blood is sucked into the blood reservoir. Further, during blood feeding, since the valve V ₃ and the valve V 3 are closed, the liquid in the liquid reservoir 6 is supplied under pressure to the closed space, and the blood in the blood reservoir is pushed out to the oxygenator 2 .

Figure 4 shows two pump devices 1 and 1' in a blood removal circuit.
This is an example in which blood is continuously sent to the artificial lung ₂ by alternately repeating expansion and contraction of the blood reservoirs 4 and 4' provided in parallel to L1, and the pump devices _{1 and 1} of the blood removal circuit L1. Valves V ₂ , V ₂ ′ and valves V ₁ , V ₁ ′ are provided on the blood inlet side and blood outlet side of ′.

In addition, valves V ₃ and 3 are installed on the liquid outlet side and the fluid inlet side of the pump device 1 of the liquid circulation circuit L ₃ , respectively.
V ₃ ', V ₈ and V ₈ ' are provided. When the blood sucked into the blood reservoir 4 of the pump device 1 is being sent to the oxygenator 2, valves V ₁ , V 2 ′, and V are installed so that the blood is sucked into the blood reservoir 4 ′ of the pump device ₁ ′. ₃ ′, V ₈ opens, valves V ₁ ′, V ₂ ,
V ₃ and V ₈ ' are controlled to be closed. On the other hand, when blood is being sucked into the blood reservoir 4, the valves V ₁ , V ₂ ′, V ₃ ′, and V ₈ are closed so that the blood in the blood reservoir 4 ′ is sent to the oxygenator.
V ₁ ′, V ₂ , V ₃ , and V ₈ ′ are opened. As the liquid feeding means 7 in FIG. 5, a constant speed pump such as a roller pump is used.

(Operation) Next, the operation of the extracorporeal blood circulation apparatus according to the present invention will be explained with reference to FIG.

[Blood feeding process]

In the blood feeding process, valve V ₁ is open, and valves V ₂ and V ₃ are closed. The blood reservoir 4, which has expanded by collecting blood, contracts as the liquid in the fluid reservoir 6 is supplied under pressure to the closed space 9 by the operation of the roller pump 7, so that the blood in the blood reservoir is artificially is pushed into the lungs.
When liquid is supplied to the closed space, equal amounts of blood and liquid between the blood and liquid reservoirs are delivered from each reservoir, so each reservoir contracts at the same rate. Therefore, in FIG. 1, a proximity switch 8b is provided close to the liquid reservoir to detect when the liquid reservoir has contracted to a preset position. When this switch is activated, the blood feeding process ends, and the opening/closing of each valve and the drive of the roller pump are controlled so that the blood feeding process ends and the next blood removal process begins.

[Blood removal process]

When the proximity switch 8b is operated, the valve V ₁ is closed by interlocking control with this switch, the valves V ₂ and V ₃ are opened, and the roller pump 7 is closed.
drive is stopped. When each of the above operations is completed, the pressurized liquid filled in the sealed space suddenly falls into the liquid reservoir 6 installed at a lower position than the blood reservoir, creating a negative pressure in the sealed room, causing the blood reservoir to expand and blood to flow out. The blood is aspirated into the blood reservoir 4. Since the blood drawn into the blood reservoir and the fluid supplied to the fluid reservoir are equal in volume, the fluid reservoir expands at the same rate as the blood reservoir. A proximity switch 8a is provided close to the liquid reservoir to detect when the liquid reservoir has expanded to a preset position. Valves and roller pumps are controlled.

By repeating the cycle of the blood feeding step and the blood removal step, it is possible to continuously and automatically control the blood to circulate smoothly in the extracorporeal blood circulation device and the patient's body.

The electric control system explained above is generally automatic, but if manual control is preferred during surgery, a means of switching between manual and automatic is provided where switching between manual and automatic is necessary. be able to.

(Effects of the Invention) The extracorporeal blood circulation device according to the present invention does not use any conventional roller type or finger type pump in the blood circuit, and uses a blood reservoir essential for an artificial lung.
A new configuration that performs a pumping action by expanding and contracting the liquid by utilizing the head of the liquid from the closed space of the liquid circulation circuit connected to the housing through the intervening liquid reservoir and the means for sending the liquid to the closed space enables the following: It has such excellent effects.

(a) Since no roller-type or finger-type pump is provided in the blood circuit, blood damage caused by the pump can be avoided and long-term use is possible.

(b) Blood collection into the blood reservoir does not need to rely on gravitational blood removal using a drop as in the past, so the blood reservoir can be located at a higher level than the patient; It does not require dangerous equipment such as a high bed or a step stool for the caster to obtain. The surgery is convenient and safe because it does not require the dangerous equipment mentioned above.

(c) Since there is no need for gravitational blood removal by head, the blood circuit can be shortened and the priming volume can be greatly reduced. Therefore, it can be applied to newborns, children, etc. who have a small amount of whole blood.

(d) Since the blood flow to the oxygenator can be accurately determined by the number of times the liquid reservoir is activated, there is no need to provide a blood flow meter in the blood side circuit. Since the blood side circuit is simplified, accidents such as blood circuit blockage can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a double-needle type extracorporeal blood circulation device according to the present invention, and FIG. 2 is a system diagram of a single-needle type blood extracorporeal circulation device,
FIGS. 3 and 4 are system diagrams showing other examples of the present invention. L ₁ ... Blood removal circuit, L ₂ ... Blood supply circuit, L ₃ ... Liquid circulation circuit, 1 ... Pump device, 2 ... Artificial lung,
4...Blood reservoir, 5...Housing, 6...
Liquid reservoir, 7...liquid feeding means, 8...detection device, _V1 , _V2 , _V3 , _V4 ...valve.

Claims (1)

[Claims] 1 A flexible blood reservoir 4 is housed in a non-flexible housing 5, and a pump device 1 is installed on the inflow side of the artificial organ 2 to repeatedly remove blood and send blood by expanding and contracting the blood reservoir using liquid pressure. Intervening blood removal circuit
In the blood extracorporeal circulation apparatus in which _a blood supply circuit _L2 is connected to an outflow side of the artificial organ, a liquid circulation circuit _L3 is provided with a flexible liquid reservoir 6 in the non-flexible housing. , the liquid reservoir is connected to the housing so as to have a head difference, and the blood inlet side and blood outlet side of the pump device ₁ of the blood removal circuit L1 and the liquid outlet side from the pump device of the liquid circulation circuit _L3 . Valves V ₂ , V ₁ , and V 3 are provided to control the expansion and contraction of the blood reservoir 4 in conjunction with the device 8, and the valves V 2 , V 1 , and V ₃ are provided on the liquid outlet side of the liquid reservoir 6 of the liquid circulation circuit L ₃ and are controlled in conjunction with the detection device 8. Liquid feeding means 7
When the detection device 8 detects the expansion of the blood reservoir, the valve V1 is opened and the valve _V1 is opened.
V ₂ and V ₃ are closed, the liquid feeding means 7 is driven to send out the blood in the blood reservoir, and when the detection device 8 detects contraction of the reservoir, the valve V ₁ is closed;
Open valves V ₂ and V ₃ , stop the liquid feeding means,
1. A blood extracorporeal circulation device configured to collect blood in a blood reservoir.