JPH0464706B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a safe extracorporeal circulation device that does not cause damage to blood even when used for a long time. In particular, the present invention relates to an extracorporeal blood circulation device equipped with an artificial lung function that can safely and completely provide respiratory assistance. The present invention will be described below as an extracorporeal blood circulation device with an artificial lung function, but it can also be applied to an extracorporeal blood circulation device with a blood purification function to remove unnecessary components from the blood and a function to replenish useful components to the blood. can also be applied.

(Prior art) In a conventional device with this type 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 artery on the outflow side. Generally, a system is adopted in which a blood pump is connected to a side 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 extracorporeally circulating blood that increases due to blood removal from the heart and lungs by removing blood by using a drop between the patient and the blood reservoir. However, this drop is usually more than 1 meter, which makes the surgery inconvenient as the patient must be raised to a high position and the surgeon must stand on a table. It was not possible to avoid the situation where the priming volume (filling liquid amount) becomes large due to the length of the process. Therefore, there was a problem that conventional devices could not be applied to neonatal and pediatric applications where the whole blood volume was small. In addition, roller-type or finger-type pumps are generally used as blood pumps, but when using these roller or finger pumps, the straining and crushing of these pumps can have a major effect on blood damage, especially a decrease in the number of platelets and hemolysis. There was a problem. For this reason, in place of roller or finger pumps, various pumps have been developed in which a flexible bag is housed in a non-flexible housing and the bag is inflated and deflated by air pressure. 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 neonates and children with small whole blood volumes. .

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

An 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 and does not cause a drop in the temperature of extracorporeally circulating blood.

(Means for Solving the Problems) The present invention includes a box that can be sealed, the inside of which is maintained at a constant temperature by being connected to a hot/cooling fan 19.
A pump device 1 is interposed on the inflow side of an artificial organ 2 to repeatedly remove blood and supply blood by expanding and contracting a flexible blood reservoir 4 housed in a non-flexible housing 5 using liquid pressure. A liquid device that houses an extracorporeal blood circulation circuit consisting of a blood circuit _L1 and a blood removal circuit _L2 interposed on the inflow side of the artificial organ 2, and has a flexible liquid reservoir 6 in the non-flexible housing. The circuit L ₄ is connected so that the liquid reservoir has a head difference with the housing, and the liquid circulation circuit L ₅ connected to the branch pipe 2 attached to the liquid circuit 4 is connected to the liquid reservoir 6. Valves V ₁ , V ₂ , V ₃ are connected to the blood inlet side and blood outlet side of the pump device 1 of the blood circuit L ₁ and to the liquid circulation circuit L 1 and are controlled in conjunction with a device 8 for detecting _expansion and contraction of the blood reservoir.
A liquid supply means 7 is provided between the liquid reservoir of the liquid circuit _L4 and the branch pipe, and a heat exchanger is provided in the liquid circuit or the liquid circulation circuit, and the detection device 8 detects the expansion of the blood reservoir. When detected, the valve V ₁ is opened, the valves V ₂ and V ₃ are closed, and the liquid feeding means 7 is driven to send out the blood in the blood reservoir. When the detection device 8 detects the contraction of the blood reservoir, the valve V ₁ is opened. This is an extracorporeal blood circulation device characterized in that it is configured to collect blood in a blood reservoir by closing valves V ₂ and V ₃ and stopping the liquid feeding means.

(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.
A liquid sealed in a liquid circuit L ₄ in which a flexible liquid reservoir 6 is connected via a liquid feeding means 7, and a liquid circulating circuit L ₃ in which a branch pipe 20 attached to the liquid circuit is connected to the liquid reservoir. is supplied to the closed space 9,
Alternatively, this can be done by discharging from a closed space. For this reason, valves V ₁ , V ₂ , and V ₃ are provided on the upstream and downstream sides of the pump device of the blood removal circuit L ₁ and on the liquid circulation circuit L ₃ to open and close each circuit as appropriate.
Further, if a heat exchanger is provided in the liquid circulation circuit _L3 or the liquid circuit _L4 , 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 cardiac output, 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 plasma components do not leak.

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.

Like the blood reservoir 4, the liquid reservoir 6 is made of a flexible material that can be expanded and contracted, and the volume when expanded can be any size.
It is preferable to use the same one as the normal 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. Due to this head difference, the liquid pressurized in the closed space flows into 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 means 7 for sending the liquid in the liquid reservoir 6 to the closed space. 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. In FIG. 1, 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 into the blood side.

The valves V ₁ , V ₂ , V ₃ that open and close the blood removal circuit L ₁ and the liquid circulation circuit L ₃ are usually electromagnetic valves, air cylinders, hydraulic cylinders, or the like. Among the above valves, valve V ₃ installed in liquid circulation circuit L ₃ is because if the valve position is higher than the reservoir, negative pressure will occur in the liquid circulation circuit between the reservoir and the valve when the valve is closed. , bubbles may form in the liquid, which may adversely affect the operation of the pump device 1. The liquid reservoir and valve V ₃ are therefore preferably in a horizontal position.

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 by a sequencer, a microcomputer, or the like.

FIG. 2 shows an example of a single-needle type extracorporeal blood circulation device using a double-lumen catheter 11. The catheter 11 is provided with a branch pipe 12, and one of the branch pipes and the inflow side of the oxygenator are connected to the pump device 1. It is connected to the interposed blood removal circuit _L1 , and 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 _V4 is configured to be opened during the blood feeding process and closed during the blood removal process.

FIG. 3 is a system diagram of an extracorporeal blood circulation apparatus in which an artificial lung is applied to an artificial organ according to the present invention.

The blood circulation circuit including the pump device 1 and the artificial organ 2 is housed in a sealable storage box 14, and the temperature of the blood in the blood circulation circuit is controlled by the hot/cold air generator 19, and at the same time, the blood is transferred to the liquid circuit _L4 . The temperature is controlled by heat exchange between the blood and the liquid heated by hot water circulated from the hot water circulator 18 to the provided heat exchanger 17 through a flexible blood reservoir.

An O ₂ blender then supplies a fixed proportion of O ₂ and air to the artificial organ. In Figure 3, an air filter 15 is installed between the _O2 blender and the artificial organ.
By providing this, it is possible to prevent impurities from entering the artificial organ. In addition, the atmosphere opening section provided between the air filter and the O ₂ blender prevents excessive pressure from being applied to the artificial organ due to an imbalance between the amount of air supplied to the artificial organ and the amount of air sucked out. Mild processing can be performed on blood.

Furthermore, when connecting the air outlet of an artificial organ to the suction line of hospital equipment, a dehumidifier 16 is installed between the two.
By providing this, it is possible to avoid damage to the air control system of hospital equipment due to moisture in the air.

As the dehumidifier, a filter type, centrifugal type, cooling type, etc. can be 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 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 actuated, 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, which is set at a lower position than the blood reservoir, resulting in a negative pressure inside 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 aspirated from 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 be smoothly circulated within the extracorporeal blood circulation device and the patient's body.

The electrical control method described above is generally automatic, but if manual control is preferred during surgery, switching means should be provided where switching between manual and automatic is necessary so that manual control can be performed. I can do it.

(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 connects the blood reservoir, which is essential for an artificial lung, to the housing with a liquid reservoir interposed. The new structure uses the head of the liquid from the closed space of the liquid circulation circuit and the means for sending the liquid into the closed space to expand and contract the pump, resulting in the following excellent effects: There is.

(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 it can be used for a long time.

(b) Blood collection into the blood reservoir does not require relying 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) Blood flow to the artificial lung can be accurately determined by the number of times the fluid reservoir is activated, so 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 drawings]

FIG. 1 is a system diagram of a double-needle type extracorporeal blood circulation device according to the present invention, FIG. 2 is a system diagram of a single-needle type extracorporeal blood circulation device, and FIG. 3 is a system diagram of the system system of the present invention. It is a diagram. L ₁ ... Blood removal circuit, L ₂ ... Blood supply circuit, L ₃ ... Liquid circulation circuit, L ₄ ... Liquid circuit, 1 ... Pump device, 2 ... Artificial lung, 4 ... Blood reservoir, 5 ……
Housing, 6...Liquid reservoir, 7...Liquid feeding means, 8...Detection device, 20...Branch pipe, _V1 , _V2 ,
V ₃ , V ₄ ... valve.

Claims (1)

[Claims] 1. A flexible blood reservoir 4 housed in a non-flexible housing 5 is placed in a sealable box to which a hot/cold air generator 19 is connected and whose interior is maintained at a constant temperature using liquid pressure. A blood removal circuit L 1 in which a pump device 1 that repeatedly removes blood and sends blood by expanding and contracting is interposed on the inflow side of an artificial organ ₂ and the artificial organ 2
A liquid circuit that houses an external blood circulation circuit consisting of a blood removal circuit _L2 interposed on the inflow side of the liquid circuit, and has a flexible liquid reservoir 6 in the non-flexible housing.
L ₄ is connected so that the liquid reservoir has a head difference with the housing, and a liquid circulation circuit L ₅ connected to the branch pipe 2 attached to the liquid circuit 4 is connected to the liquid reservoir 6. Blood inlet side and blood outlet side of pump device 1 of blood circuit L ₁ and liquid circulation circuit
Valves V ₁ , V ₂ , and V ₃ which are controlled in conjunction with a device 8 for detecting expansion and contraction of the blood reservoir are provided in L ₁ , and a liquid feeding means 7 is provided between the liquid reservoir and the branch pipe of the liquid circuit L ₄ . and a heat exchanger is provided in the liquid circuit or liquid circulation circuit, and when the detection device 8 detects expansion of the blood reservoir, a valve is activated.
V ₁ is opened, valves V ₂ and V ₃ are closed, and the liquid feeding means 7 is driven to send out the blood in the blood reservoir. When the detection device 8 detects the contraction of the blood reservoir, the valve V ₁ is closed. , an extracorporeal blood circulation apparatus characterized in that the blood is collected in a blood reservoir by opening valves V ₂ and V ₃ and stopping the liquid feeding means.