JP4051812B2 - Extracorporeal circulation device with control function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blood extracorporeal circulation device, and more particularly to a simple and minimally invasive extracorporeal circulation device having a function of controlling a circulatory state.
[0002]
[Prior art]
In heart / macrovascular surgery, the heart must be temporarily stopped or nearly stopped, and an extracorporeal circulation device is used to replace the heart and lung functions with a machine. As shown in FIG. 8, a conventionally used extracorporeal circulation apparatus includes, as main elements, a blood removal vessel 2, a blood reservoir 83, a heat exchanger 5, a main pump 86, an artificial lung 7, a filter 9, and a blood supply tube 10. And the elements are sequentially arranged in the blood circuit.
[0003]
The blood removal vessel 2 is inserted into the upper and lower vena cava or the right atrium of the patient 1 and is as thick as possible in order to increase the flow rate. As the blood reservoir 83, an open type in which blood is in contact with air is often used, and blood flows in through blood removal by drop blood removal using a drop between the patient 1 and the blood reservoir 83. A small number of closed-type blood reservoirs in which blood does not come into contact with air are also used, and some blood flows through blood vessels by forced blood removal using a blood pump. Some open-type blood reservoirs generate an alarm because the risk of air being fed into the circuit increases when the stored blood volume decreases, but there is no known one that actively adjusts the volume. The heat exchanger 5 is often installed in a blood reservoir, and a liquid (usually tap water) heated or cooled by a heating / cooling device 4 is perfused into a metal tube to heat the blood. Cooling. The main pump 86 is a roller pump or a centrifugal pump, and is installed downstream of the blood reservoir. There is no example where the main pump is installed upstream of the blood reservoir. The whole extracorporeal circulation device is large, and it is necessary to secure a large space as compared with general surgery. In addition, it is not suitable for carrying because it is a large machine, and it is always installed in the operating area.
[0004]
The operation of the extracorporeal circulation device is performed by arranging special personnel for that purpose. The extracorporeal circulation operator is usually assigned by an extracorporeal circulation engineer, but may be performed by a doctor. In any case, special personnel with advanced skills are required. The extracorporeal circulation operator is located beside the operating table and never participates in the surgical operation or is located in a remote place. The extracorporeal circulation operator adjusts the volume of the blood reservoir and the pump flow rate by manual operation in consideration of the optimum extracorporeal circulation blood flow rate while observing the degree of blood removal and the arterial pressure of the living body. Therefore, the extracorporeal circulation operator cannot leave the extracorporeal circulation device during the extracorporeal circulation.
[0005]
By the way, in order to effectively use human and economical medical resources, minimally invasive surgery is actively introduced in the surgical field. Minimally invasive surgery in the field of cardiac surgery is called MICS (Minimally Invasive Cardiac Surgery). In MICS, the midline sternotomy is not performed to reduce invasion, and the skin incision is made as short as possible. This limits the field of view for exposing the heart. Therefore, a thin blood vessel used for the extracorporeal circulation device is preferably a thin blood vessel that does not interfere with the visual field.
[0006]
[Problems to be solved by the invention]
A main object of the present invention is to provide an extracorporeal circulation device that is easy to operate and can be automated. It is also an important objective to realize an extracorporeal circulation device that enables minimally invasive extracorporeal circulation. The problems to be solved by the present invention will be described in detail below.
[0007]
<Labor saving and easy operability>
Conventionally, when extracorporeal circulation is required in cardiac / macrovascular surgery, personnel for operating the extracorporeal circulation have been required. In addition, the operation of the extracorporeal circulation apparatus is complicated and requires advanced techniques and requires experience. Accordingly, an object of the present invention is to provide an apparatus that can control operation mechanically, is easy and simple to operate, and can save labor.
[0008]
<Minimally invasive>
Side effects of extracorporeal circulation on the living body include blood dilution, bleeding due to administration of a large amount of an anticoagulant, hemolysis and inflammation caused by blood cell destruction, and reduction of organ blood flow due to non-physiological steady flow. In order to reduce these side effects, an extracorporeal circulation device that can achieve minimally invasiveness is desirable. On the other hand, since blood removal used in MICS and the like is thin, an appropriate amount of blood removal may not be obtained. Accordingly, an object of the present invention is to provide an apparatus that can ensure the flow rate of blood flowing through a circulation system while ensuring minimal invasiveness.
[0009]
<Safety>
Since conventional extracorporeal circulation devices do not have sufficient safety mechanisms, the safety depends mainly on the skill of the engineer who operates the extracorporeal circulation. Accordingly, an object of the present invention is to provide an apparatus having a safety mechanism in terms of hardware or software.
[0010]
<Miniaturization and ensuring portability>
Conventional extracorporeal circulation devices are large and require a large space. In addition, movement is difficult, which hinders the flexible operation of equipment. Accordingly, an object of the present invention is to reduce the size of the circulation system and improve the mobility.
[0011]
[Means for Solving the Problems]
  In order to solve the above problems, an extracorporeal circulation apparatus according to the present invention is an extracorporeal circulation apparatus configured to circulate blood extracorporeally by disposing a predetermined element in a circuit, and includes a blood pump and a capacity to be stored Actively increase or decreaseLetA blood reservoir having a volume adjusting means for detecting the volume and a volume detecting means for detecting the volume; and an output of the volume detecting means is supplied to control the volume of the blood reservoir via the volume adjusting means, and the flow rate of the blood pump And control means for controlling. The blood reservoir has a blood chamber for storing blood and a pressure regulation chamber provided adjacent to the blood chamber, which are provided in a lumen of a housing made of a hard material. The blood chamber is a closed type in which the blood in the chamber is not in contact with outside air, and is provided with a blood inflow connection tube and a blood outflow connection tube. The pressure adjusting chamber is provided with a connecting pipe connected to the volume adjusting means, and the blood chamber and the adjacent portion of the pressure adjusting chamber are in contact with each other via a flexible partition wall. The volume adjusting means is configured to adjust the volume of the blood chamber by allowing a liquid to flow into and out of the pressure adjusting chamber to deform the partition. The capacity detecting means is based on the capacity adjusting means.RuThe amount of liquid flowing into and out of the pressure control chamberBased onIt is configured to detect the volume of the blood reservoir. The control means includesBased on the detection value supplied from the capacity detection means,By controlling the volume adjusting means to increase / decrease the volume of the blood reservoir, it is possible to adjust the amount of extracorporeal blood circulation. According to this configuration, since the blood reservoir has the volume adjusting means and the volume detecting means, and the volume can be controlled, the operation of the apparatus does not require an operator's advanced technology and is easy. It becomes simple.
[0012]
  Preferably, provided with a circulation state detection means for detecting the circulation state in the circuit, the control means according to the output detected by the circulation state detection means,Extracorporeal circulation volumeConfigure to adjust. Thereby, automatic driving becomes easy.
[0017]
  Further preferably, the circulating state detecting means is constituted by a pressure sensor provided at the inflow portion.The ThisAccording to these configurations, it is possible to prevent excessive negative pressure from being applied to the blood vessel and to reduce the possibility of drawing in air, thereby increasing safety.The
[0018]
Further preferably, the control means detects the suction of the blood removal part based on the information obtained from the circulatory state detection means, and when the suction is detected, reduces the rotation speed of the blood pump or the blood reservoir. Control to lower the capacity. Thereby, it is possible to easily cope with the sucking of the blood removal part, and the sticking can be prevented, thereby improving the safety.
[0019]
  FurtherPreferably, the increase in the extracorporeal circulation flow rate is performed by at least one of the operation of increasing the rotation speed of the blood pump or decreasing the capacity of the blood reservoir, and the decrease in the extracorporeal circulation flow rate decreases the rotation speed of the pump, Alternatively, it is configured to be performed by at least one of operations for increasing the capacity of the blood reservoir. This facilitates automatic operation of extracorporeal circulation.
[0020]
Further, preferably, a means for generating a pulsatile flow in the circulation system by periodically increasing or decreasing the rotation speed of the blood pump or by periodically increasing or decreasing the capacity of the blood reservoir is provided. As a result, appropriate organ perfusion can be obtained even in patients with complications such as cerebrovascular disorders and renal failure.
[0021]
Further, preferably, at least the blood pump, the blood reservoir, the oxygenator, and the filter among the elements disposed in the circuit are integrally assembled. Thereby, portability increases.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be outlined with reference to the drawings. FIG. 1 shows an extracorporeal circulation device according to an embodiment of the present invention. In addition, although the same number was attached | subjected about the component same as the prior art example of FIG. 8, the arrangement | positioning is not necessarily the same as a prior art example.
[0024]
In the circuit from the blood removal vessel 2 to the blood supply tube 10, a filter 9, a main pump 6, an artificial lung 7, and a blood reservoir 3 are arranged as main elements from the upstream (the blood removal side) to the downstream. Are connected by short tubes. The blood reservoir 3 and the main pump 6 are provided with a driving device 38a and a driving motor 38b, respectively. Furthermore, an in-circuit pressure measurement port 37 including a pressure sensor and an ultrasonic flow meter probe 31 are provided at the inflow portion of the circuit (the inflow portion referred to in the present invention refers to a part of the blood circuit upstream of the main pump). Has been placed. Reference numeral 39 denotes a controller serving as a control means, which is connected to the blood reservoir 3, the main pump 6, the circuit internal pressure measurement port 37, and the ultrasonic flowmeter probe 31 by wiring 40. 11 shows the flow of blood in the circuit.
[0025]
The blood reservoir 3 has capacity adjusting means for actively increasing or decreasing the capacity to be stored. The drive device 38a is a part of the element of the capacity adjusting means. Although not shown in FIG. 1, the blood reservoir 3 has a volume detection means for detecting the volume. The circuit internal pressure measurement port 37 and the ultrasonic flowmeter probe 31 are means for detecting a circulation state in the circuit.
[0026]
The controller 39 controls the capacity of the blood reservoir 3 and the main pump 6 in accordance with the outputs of the circuit pressure measurement port 37 and the ultrasonic flowmeter probe 31. Since the controller 39 has a reference value for control and performs control based on the reference value, the controller 39 has a setting unit for setting the reference value. The reference value is preferably set to be variable, but may be fixed depending on use conditions. Further, it is not essential that the control by the controller 39 is automatically performed by the output of the circuit pressure measurement port 37 and the ultrasonic flowmeter probe 31. This is because the main part of the effect of the present invention can be obtained even if the controller 39 is manually operated, since the blood reservoir 3 has the capacity adjusting means. The main ones of the above elements will be described in detail below.
[0027]
<Blood reservoir 3 and its volume control device>
As shown in FIG. 2, the blood reservoir 3 includes a blood chamber 16 for storing and storing blood, and a pressure adjusting chamber 17 for adjusting the internal volume of the blood chamber 16. Both chambers 16 and 17 are separated by a flexible partition wall (diaphragm) 18. 3a and 3b are connection pipes for connecting to the circuit, and 3c is a connection pipe for connecting the pressure adjusting chamber 17 and a capacity adjusting device (not shown). Although not shown in FIG. 2, it has a volume detection means for detecting the stored blood volume. The blood reservoir 3 can actively adjust the amount of stored blood by a volume adjusting device. As the blood reservoir 3 and its volume adjusting device in the present invention, various forms can be used. We will explain them while classifying them.
[0028]
In general, blood reservoirs incorporated in an extracorporeal circuit include an open type in which blood and air are in contact with each other and a closed type in which no blood is in contact with them. Conventional extracorporeal circulation devices often incorporate an open reservoir. However, in order to provide a simple extracorporeal circulation device, an open-type reservoir that must constantly monitor the amount of blood stored in the reservoir is not suitable. Therefore, in the present invention, the closed type is preferable. As a volume adjusting device for actively increasing or decreasing the blood volume of the blood chamber, a first fluid pressure type that adjusts the blood volume by compressing and pulling the blood chamber through liquid or gas, Second, there is a mechanical type that adjusts the blood volume by directly mechanically pulling and pulling the blood chamber.
[0029]
In the first fluid pressure type, as shown in FIG. 2, there are two blood chambers 16 for containing blood and a pressure adjusting chamber 17 for enclosing the whole or a part of the blood chamber and containing gas or liquid for pressure adjustment. There is a room. In the blood chamber 16, the whole or a part of the container is soft, and the pressure in the pressure adjusting chamber 17 is reflected in the blood chamber 16 through the soft portion of the blood chamber 16, and the volume of the blood chamber 16 is adjusted. The FIG. 2 shows a blood reservoir having a flexible diaphragm 18 among fluid pressure types.
[0030]
The pressure medium may be a gas or a liquid. Any liquid can be used as long as it has fluidity. Degassed physiological saline that has been sterilized to remove dissolved gas is preferred, but it may be mere water that is not sterilized because it does not come into direct contact with blood. A blood reservoir capacity adjusting device that sends a fluid such as liquid or gas into the pressure adjusting chamber to generate an appropriate pressure can be incorporated in the blood chamber, but may be installed separately via a tube. When incorporated, the entire system becomes compact. When separated, the blood chamber itself is compact, and there are less restrictions on the place where the blood chamber is installed.
[0031]
The blood reservoir capacity adjusting device may be anything that can generate an appropriate pressure. If the medium is air, it is possible to use a compressor with adjustable pressure. When the medium is a liquid, there are a method (capacity defining method) that regulates the direct volume such as a syringe or bellows, and a method (pump fluid pressure regulating method) that regulates the fluid pressure using a liquid feed pump.
[0032]
An apparatus having a structure as shown in FIG. 3 can be used for the capacity defining method. FIG. 2A shows a device for defining the capacity of the pressure regulating chamber using a piston 19. The pressure that is adjusted depending on the position of the piston 19 is transmitted to the pressure adjusting chamber 17 through the connecting pipe 19a. In FIGS. 5B, 5C, and 5D, the volumes are adjusted by the syringe 20, bellows 21, and pusher plate 22, respectively. Similarly to (a), each is connected to the pressure regulating chamber 17 via the connecting pipes 20a, 21a, 22a. The piston 19, the syringe 20, the bellows 21, and the pusher plate 22 are driven by a motor or the like.
[0033]
In the pump fluid pressure regulation system, the volume of the pressure regulation chamber is regulated using a fluid feed pump for a blood reservoir capacity regulator. Any pump can be used as long as it can feed liquid. The required performance is small, excellent in reliability and durability, excellent in response regardless of the direction of liquid feeding, capable of generating a high pressure, and inexpensive. Specific examples include a centrifugal pump, a mixed flow pump, an axial pump, a friction pump, a gear pump, and a roller pump. Since the centrifugal pump and the mixed flow pump have one direction of liquid feeding, a switching valve for changing the direction is necessary. 4A and 4B show examples using a roller pump 23 and an axial flow pump 24, respectively. In the figure, reference numeral 25 denotes a liquid storage chamber for liquid feeding.
[0034]
As the second mechanical type, a configuration as shown in FIG. 5 can be used. In this case, the blood reservoir capacity adjusting device has a structure directly coupled to the blood chamber. FIG. 5A shows an example using a piston 12. The blood chamber 12 c is a container whose capacity is variable depending on the position of the piston 12. Reference numerals 12a and 12b are connection pipes for connecting to the circuit. (B), (c), and (d) show examples in which the volumes are adjusted by the syringe 13, bellows 14, and pusher plate 15, respectively. As a drive source, a motor, an electromagnet, or the like is used, and the capacity is adjusted by receiving some kind of compression traction.
[0035]
In both the first mechanical type and the second hydraulic type, the shape of the blood chamber must be reduced in the number of blood flow stagnation sites in order to enhance antithrombogenicity. It is considered that the fluid pressure type is superior to the mechanical type in terms of antithrombogenicity because the design of the blood chamber is less restricted. On the other hand, the mechanical type can be manufactured at low cost because the mechanism is simple and the number of parts is small. The adjustment range of the blood chamber volume depends on whether the target patient is an adult or a child, but it is desirable that the blood chamber volume can be adjusted from 100 ml to 4000 ml for an adult.
[0036]
Various configurations can be used as the configuration of the volume detection means for detecting the volume of the blood chamber. If a piston, syringe, and bellows are used in the blood chamber, the capacity can be simply detected from the displacement position of the rotation shaft of the drive motor. The volume of the blood chamber can also be increased by attaching a capacitance sensor such as a hall sensor or an ultrasonic crystal to the blood chamber or pressure control chamber, or measuring the impedance or conductance with a current voltmeter by applying a weak current to the blood chamber. It can be measured. In the case of the fluid pressure type, when the fluid is a liquid, the volume of the blood chamber can be measured even if the volume of the liquid discharged from the regulation chamber through the tube is measured with a liquid meter. There are many methods for measuring the volume of the discharged liquid because of its high degree of freedom, but it is also possible to simply measure the weight with a weigh scale. Note that a means for supplying detection data to the controller 39 is necessary. For this purpose, for example, the detection result is output as an electric signal.
[0037]
It is possible to incorporate a heat exchanger into the blood reservoir in the present invention. There are several ways to incorporate a heat exchanger, for example: First, a tube made of a material having an excellent heat exchange capacity is installed in the blood chamber of the blood reservoir, and the heated or cooled liquid is perfused into the tube, thereby heating the blood and the living body. Cooling is possible. Secondly, in a mechanical reservoir using a pusher plate, the blood and thus the living body can be heated and cooled by heating or cooling the pusher plate. If limited to heating only, a method of incorporating a heater into the pusher plate is conceivable, which is a simple and effective method. Third, the hydraulic reservoir can heat or cool the blood and thus the living body by heating or cooling the liquid in the pressure regulation chamber. Rather than installing a heat exchanger in the blood chamber, it is considered that there is no blood stagnation and the antithrombogenicity is enhanced, and this is an effective method for enhancing minimal invasiveness.
[0038]
<Main pump 6>
Next, the main pump 6 will be described. Since the blood removal used in MICS and the like is thin, an appropriate blood removal amount may not be obtained. Therefore, it is necessary to apply an appropriate negative pressure that is not excessive for blood removal. In head blood removal, there is a limit to the additional negative pressure, so forced blood removal using a pump is preferable. In addition, in blood removal, it is necessary to raise the operating table in order to increase the head, but in forced blood removal, the same operating table as in general surgery other than the heart can be used, which is effective in operating the operating room. .
[0039]
Generally, there are a volumetric pump and a non-volumetric pump. Roller pumps often used for extracorporeal circulation devices are classified as positive displacement pumps. The problem with using a positive displacement pump as the main pump of the extracorporeal circulation system and installing it upstream from the blood reservoir is that when a circuit failure such as suctioning occurs in the blood removal vessel, an excessive shadow is placed on the inflow portion of the pump. Pressure is generated. Excessive negative pressure may damage the biological tissue of the blood removal part and cause serious troubles such as drawing air into the circuit. For this reason, the type of the main pump installed upstream from the blood reservoir is preferably a non-displacement type pump that does not generate an excessive negative pressure even if suction or the like occurs and has excellent adjustability. A typical non-positive displacement pump is a turbo pump such as a centrifugal pump, a mixed flow pump, or an axial flow pump. Any of these can be used in the present invention. However, in order to generate a high pressure, the axial flow pump needs to have a very high rotational speed, and is not a preferable choice in view of hemolysis and durability. Therefore, a centrifugal pump or a mixed flow pump is preferable.
[0040]
<Controller 39 and circulating state detection means>
Next, the control of the circulation state by the controller 39 in the extracorporeal circulation apparatus of the present invention will be described. Computer control is required to simplify the operation of the extracorporeal circulation device, and most preferably to achieve automatic control. Several methods are conceivable for the control, and combinations are also effective.
[0041]
The first method is sticking detection and prevention by pressure. That is, the pressure at the inflow portion of the circuit is monitored, and suction is detected from the pressure waveform. If suction occurs, control is performed to reduce the number of rotations of the pump or the capacity of the blood reservoir. The pressure at the inflow portion reflects the venous pressure, and is normally a steady flow with almost no pulse pressure. However, if the blood vessel is adsorbed, abnormal pressure waveform disturbance characterized by a rapid pressure drop occurs. This appears as an increase in pulse pressure, an increase in pressure change (increase in absolute value of pressure differential value), and a change in pressure frequency component. This is detected by the pressure sensor of the pressure measurement port 37 constituting the circulation state detection means, and information obtained thereby is transmitted to the controller 39 which is the control means. A computer is incorporated in the controller 39, and the main pump 6 and / or the blood reservoir are adjusted so that blood flows smoothly in the extracorporeal circulation device according to information obtained from the pressure sensor.
[0042]
The second method is a control method in which the minimum limit value of the inflow portion pressure is set, and if it falls below the set value, the rotational speed of the pump is lowered or the volume of the blood reservoir is lowered. The minimum limit is unavoidable to some extent, but negative pressure below -100mmHg is prevented because it may cause troubles such as cavitation of the main pump and unexpected air drawing into the circuit. There must be. Also in this case, as in the first method, the pressure sensor 37 shown in FIG. 1 is used as the circulating state detecting means in order to measure the inflow portion pressure of the circuit. The controller 39 needs to be provided with means for setting the minimum limit value of the inflow portion pressure.
[0043]
The third method is to measure the current consumption or power of the blood pump, detect the suction of the blood removal part from the waveform of the current consumption or power, and if the suction appears, reduce the rotation speed of the pump, or blood This is a control method for reducing the capacity of the reservoir. This is basically the same as the first method, but does not require a special sensor because internal data held by the pump motor is used, leading to cost reduction. In this case, since the current consumption and power consumption of the drive device (motor) driving the blood pump must be measured, a means for monitoring the current or power of the pump motor is required as the circulation state detection means. Become.
[0044]
The fourth method sets the target arterial pressure or extracorporeal blood flow rate of the living body, and if either or both of the arterial pressure and the flow rate are below the set value, the pump rotation speed is increased, or the blood This is a control method in which the volume of the reservoir is reduced, and if both the arterial pressure and the flow rate exceed the set values, the pump rotational speed is reduced or the blood reservoir capacity is increased. The arterial pressure and the extracorporeal blood flow rate to be set must be determined according to individual differences in the living body, the surgical method, and the state of the living body, and cannot be set to the same value in any situation. However, it is possible to determine the target arterial pressure and the extracorporeal blood flow rate suitable for individual cases in advance, and it is not necessary to change the set value frequently during the extracorporeal circulation. It is not particularly limited which of the pump rotation speed and the blood reservoir volume is preferentially adjusted, and both are possible.
[0045]
One preferred method is to set an optimal upper limit value (denoted as Arpm) for the pump speed and control it in a direction that maximizes the blood reservoir volume and maximizes it (full blood removal) until it exceeds Arpm. However, if it is necessary to exceed Arpm in order to increase the blood flow rate, a method of reducing the blood reservoir capacity without increasing the rotational speed can be considered. Moreover, during the extracorporeal circulation, administration of a pressor or a vasodilator is also necessary, and appropriate treatment is necessary as appropriate. In the case of the fourth method, the circulation state detection means provided in the extracorporeal circulation device is not particularly limited as long as it can measure the arterial pressure of the living body and the extracorporeal circulation blood flow rate. For example, the (blood) pressure provided in the blood circuit A monitor line, a blood flow meter, etc. are mentioned.
[0046]
<Simplification of circuit and system>
By simplifying the circuit and making the tube as short as possible, the filling amount of the extracorporeal circuit can be reduced. The decrease in filling amount can contribute to minimal invasiveness by suppressing the occurrence of edema due to blood dilution and greatly reducing the need for blood transfusion. In addition, by assembling the circuit in advance at the manufacturing level, labor required for assembly can be omitted, leading to labor saving and cost reduction. In addition, if the circuit is filled at the manufacturing level, preparations before surgery can be further reduced. In addition, the conventional extracorporeal circulation device is large, needs to secure a large space, and is difficult to move, which hinders the elastic operation of the equipment. In the present invention, it is possible to design the circuit and the drive device in a compact manner and to ensure portability, and these problems are also solved.
[0047]
<Pulse and vibration addition device>
In patients with complications such as cerebrovascular disorder and renal failure, the effectiveness of extracorporeal circulation with pulsatile flow has been observed. Therefore, also in the present invention, it is effective to be able to add pulsation and vibration in order to achieve minimal invasiveness. The following can be considered as a method of adding pulsation and vibration. The first method is to generate a pulsatile flow by periodically increasing or decreasing the rotational speed of the pump. The second method is to generate pulsatile flow or vibration by periodically increasing or decreasing the capacity of the blood reservoir. In particular, the latter is a novel method that takes advantage of the characteristics of a blood reservoir capable of actively adjusting the volume. It is also possible and effective to use the first and second methods in combination.
[0048]
<Antithrombotic treatment>
An antithrombotic treatment is applied to the blood contact surface of the circuit. Furthermore, in the present invention, a closed type that does not come into contact with air and a blood reservoir with improved antithrombogenicity with few blood flow stagnation sites is used, so that extracorporeal circulation with less anticoagulant is coupled with antithrombotic treatment. It becomes possible. Specifically, in normal extracorporeal circulation, an anticoagulant such as heparin is administered to maintain the activated coagulation time at 400 seconds or longer, and the operation can be performed in 200 to 250 seconds. As a result, bleeding is reduced, which is effective for increasing the minimally invasiveness of the extracorporeal circulation device, such as shortening the operation time and reducing the need for blood transfusion.
[0049]
<Separate operation panel>
As shown in FIG. 6, the separation type operation panel 26 that can be installed in the operation field is used, and operations necessary for control can be performed from the operation field. This reduces the need to provide a special extracorporeal circulation operator, leading to labor saving. As the separation type operation panel, a touch panel type liquid crystal display with a transparent sterilization cover 27 is considered. A user interface that is installed within the reach of the surgeon 28 (or the first assistant) and is capable of monitoring and controlling the extracorporeal circulation while performing surgery using sound and voice is preferable.
[0050]
<Remote operation function>
If the operation of extracorporeal circulation is more automated from manual operation, remote monitoring and control becomes possible. For example, data necessary for monitoring and controlling the extracorporeal circulation is placed on the network with a universal instrument and communication standard (for example, a combination of GPIB and TCP / IP), and the extracorporeal circulation is concentrated. Collectively manage in the management room. In large hospitals where many extracorporeal circulation devices are operated at the same time, this is an effective method leading to labor saving. In addition, all data can be recorded and saved, which is useful for academic use.
[0051]
<In-circuit air mixing prevention device>
Aeration into the circuit is one of the serious troubles that occur during extracorporeal circulation operation. The fact that it is a simple system means that the safety is so high that it can be used easily. There are several methods for dealing with air contamination. First, an ultrasonic flow meter is used as a flow meter for monitoring the extracorporeal blood flow, and the bubble meter has a bubble detection function. As shown in FIG. 1, an ultrasonic flowmeter probe 31 is attached to the inflow portion of the circuit, and if a bubble is detected, an alarm is immediately issued to deal with it.
[0052]
Second, the filter 32 is installed at the circuit inflow portion. The filter 32 is installed at the highest point of the circuit so that air can accumulate. Third, as shown in FIG. 7, an optical sensor 33 for detecting air is installed in the filter 32. If air accumulates, this is detected, an alarm is issued immediately, and the pump is stopped. Let Fourth, a port 34 for exhausting air is installed at the top end of the filter 32, and the port 34 is connected to the suction circuit 35. Normally, this port 34 is blocked by a circuit breaker 36. If air accumulates in the filter 32, the port is immediately or automatically unblocked, and the air is sucked and discharged outside. It is possible and effective to combine a plurality or all of these methods. In addition, 30 in FIG. 7 shows the flow of blood.
[0053]
<Linking with peripheral devices>
The extracorporeal circulation device requires several peripheral devices depending on the surgical procedure. That is, a suction circuit, a suction circuit reservoir, a blood concentration device (cell saver, ultrafiltration device), a myocardial protective fluid circuit, an infusion device, a vent circuit, and the like. In the present invention, it is effective to work with these devices.
[0054]
(More specific embodiment)
Hereinafter, a more specific embodiment suitable for the mitral valve operation under MICS will be described as an example of the operation using the extracorporeal circulation apparatus of the present invention.
[0055]
<Configuration of extracorporeal circulation device>
As shown in FIG. 1, the filter 9, the pump 6, the artificial lung 7, and the blood reservoir 3 are sequentially connected with a short tube from the upstream side (the blood removal side) to the downstream side (the blood feeding side) of the circuit. These are preferably compact and have a small amount of filling liquid. It is convenient if these are already assembled at the time of shipment. These are preferably supplied in a sterilized manner, and coupled with being compact, it is possible and effective to install them in a sterilized surgical field. If it can be installed in a sterilized surgical field, a tube for connection with a blood removal vessel or a blood vessel can be further shortened, and the total amount of filling liquid can be further reduced. The purpose of the filter is to remove impurities and capture / shut off air mixed in the circuit. To capture air, install at the highest position in the entire circuit.
[0056]
The pump is preferably a turbo pump, but more preferably a small mixed flow pump. If the motor for driving the pump is waterproof and can be sterilized, it can be installed in the sterilization field and is easy to handle. Alternatively, handling is more convenient if it is made of the same disposable as the pump and sterilized. Any artificial lung can be used, but a compact one is preferred. Those excellent in gas exchange ability and blood compatibility are particularly preferred, and in this respect, the membrane type is better than the bubble type. The blood reservoir is capable of mechanically measuring and adjusting the stored blood volume. Although various aspects can be considered, an example is given about each of a mechanical type and a hydraulic type.
[0057]
The mechanical type uses a pusher plate. The blood chamber of the blood reservoir consists of a rigid housing and a flexible membrane. The blood reservoir driving device includes a hard pusher plate for compressing a flexible membrane of the blood chamber, a motor for compressing and pulling the pusher plate, and a motor controller. The pusher plate must be able to uniformly press the flexible membrane of the blood reservoir. It is preferable to install the blood reservoir so that the pusher plate is horizontal with respect to the floor because the load applied to the pusher plate is uniform. A heater is embedded in the pusher plate, and if necessary, the patient's body temperature is raised. The motor must have means for converting rotation into linear motion, but may be a linear motor that produces linear motion from the beginning. The motor controller mainly controls the position of the motor. The blood volume is measured by detecting the position of the motor.
[0058]
In the hydraulic system, a flexible partition (diaphragm) is placed inside a transparent rigid plastic container, and two cavities, a blood chamber and a pressure regulation chamber, are provided. The pressure regulation chamber is connected to a liquid storage chamber for liquid feeding by a connection tube. The pressure regulation chamber, the liquid storage chamber, and the connection tube are filled with a liquid for liquid feeding (using tap water). A roller pump is installed in the middle of the connection tube, and the volume of the pressure chamber is adjusted by rotating the roller pump in the forward direction or the reverse direction. As a result, the volume of the blood chamber is adjusted. In the hydraulic system, the blood reservoir can be installed at any angle with respect to the floor, and the installation flexibility is high. A heater is embedded in the pressure control chamber, and if it is necessary to raise the patient's body temperature, it is heated. As shown in FIG. 1, a circuit internal pressure measurement port 37 is provided in the inflow portion to monitor the inflow portion circuit internal pressure. Moreover, an ultrasonic flowmeter (with a bubble detection function) probe is attached to the inflow part.
[0059]
Adds a function to generate pulsatile flow to the extracorporeal circulation device. A powerful pulsation adding ability can be obtained by periodically changing the rotation speed of the pump motor and the capacity of the blood reservoir in synchronization. The connection order of each component of the extracorporeal circulation apparatus of the present invention requires consideration different from that of the conventional extracorporeal circulation apparatus. The filter is installed in the uppermost stream because the main purpose is to capture and block air mixed in the circuit. Negative pressure is upstream and positive pressure is downstream. Therefore, the artificial lung is placed on the positive pressure side. The blood reservoir can be installed on either the negative pressure side or the positive pressure side, but it is preferable to install the blood reservoir on the positive pressure side in the case of the mechanical type described above. The reason is that if the pressure in the blood chamber is positive, there is no need to forcibly pull the pusher plate, and there is no need to bond and fix between the flexible membrane of the blood reservoir and the pusher plate, which is convenient in assembly. In order to generate pulsatile flow using the blood reservoir, it is desirable to install the blood reservoir most downstream. From the above, it is desirable that the filter, the pump, the artificial lung, and the blood reservoir are in this order from the upstream (the blood removal side) to the downstream (the blood feeding side) of the circuit.
[0060]
There are many functions required for a controller for driving and controlling an extracorporeal circulation device. Among these functions are at least the rotation and control of the pump motor, the drive and control of the blood reservoir drive motor, the transducer and amplifier for measuring the inflow circuit internal pressure, the ultrasonic flowmeter (with bubble detection function), and the separation type operation panel Communication, external data input such as patient blood pressure, control of the entire system, and the like. Furthermore, the function of interlocking with the suction circuit, the reservoir for the suction circuit, the blood concentrator (cell saver, ultrafiltration device), the myocardial protective fluid circuit, the infusion device, the vent circuit, and the like is also effective. An input / output function for monitoring / control data via a network is also effective. The controller is preferably small and movable in order to save space and portability of the system.
[0061]
<Surgery settings>
The filter, pump, artificial lung and blood reservoir constituting the extracorporeal circulation apparatus of the present invention can be installed in a sterile surgical field in a short time by assembling at the time of shipment and completing sterilization. The circuit can be filled and vented before or after installation in the sterile surgical field. In addition, if a silicon membrane type lung that does not leak is used, it is possible to complete the filling process at the time of shipment, which leads to a significant labor saving. A venting port is provided in the filter and blood reservoir. An extracorporeal circulation controller is installed near the operating table. Monitor the pressure in the inflow circuit and attach a sterilized ultrasonic flow meter (with bubble detection function) probe. Furthermore, a suction circuit, a myocardial protective liquid circuit, etc. are prepared. Put a transparent sterilization cover on the separable operation panel and install it in a place where it is easy for the operator to operate. Drive extracorporeal circulation in cooperation with the surgeon, surgical assistant and anesthesiologist. Therefore, no special personnel are assigned solely for the operation of the extracorporeal circulation device.
[0062]
<Surgery>
An example of the procedure for mitral valve surgery under MICS using the extracorporeal circulation apparatus of the present invention will be described. The skin incision should be as short as possible, and a partial midsternal incision will be made to expose the heart. In addition, a small incision is made in the right groin to expose the femoral artery and vein. A blood vessel is inserted into the femoral artery, and a blood vessel is inserted from the femoral vein into the inferior vena cava. A devascularization is inserted directly into the superior vena cava from the sternotomy. A double snare with tape is applied to the right atrium near the superior and inferior vena cava to make a tourniquet. This tourniquet must be able to sufficiently block air from being drawn even by forced blood removal due to negative venous pressure. The thickness of devascularization varies depending on the patient, but a thin one is easy to insert and does not interfere with the visual field. A cannula for myocardial protective fluid injection is installed in the ascending aorta. The extracorporeal circulation circuit that has been filled and evacuated is connected to the blood supply and devascularization attached to the patient. Confirm that there is no problem in the entire circuit and start extracorporeal circulation.
[0063]
The extracorporeal circulation is basically capable of automatic operation. On the condition that the patient arterial pressure does not fall below the preset value, the pump speed is increased until the set flow rate is obtained. Once the set flow rate is obtained, the volume of the blood reservoir is then increased. Increase blood reservoir capacity as long as patient arterial pressure and flow allow. After confirming that stable extracorporeal circulation is obtained, the ascending aorta is blocked, myocardial protective fluid is injected, and the heart is stopped. The perfused myocardial protective fluid or bleeding is aspirated and collected in a reservoir for the aspiration circuit. The collected liquid is processed by a blood concentration device (cell saver, ultrafiltration device, etc.) and transfused into the patient. The operation of the blood concentrator is simple and can be performed without a specially trained extracorporeal circulation technician.
[0064]
The upper and lower vena cava is blocked, and the right atrial / atrial septal incision or left atrial incision leads to the mitral valve. Mitral valve surgery, for example, mitral valve replacement and mitral valvuloplasty, is the same as usual even with MICS. After completing the mitral valve treatment, the air in the heart is sufficiently removed, the ascending aorta is released, and the heart incision is completely sutured closed. Release the upper and lower vena cava blockage, lower the extracorporeal circulation flow rate, and end the extracorporeal circulation if the heartbeat is sufficient. The withdrawal operation from the extracorporeal circulation needs to be performed manually to some extent, but since it is after the end of the intracardiac operation, an operator or a surgical assistant can be performed.
[0065]
<Safety measures against air contamination>
A serious problem during extracorporeal circulation is air contamination in the circuit. In particular, when a closed blood reservoir is used, there is a problem because there is a risk that the air will be sent to a patient's artery unless air is immediately removed. The place where air is mixed is on the negative pressure side upstream of the pump. Therefore, it is important not to provide an unnecessary port on the negative pressure side. Also, it is necessary to devise such that the connection part of the circuit cannot be easily disconnected. Even if there is no problem with the circuit itself, air may be drawn from the heart into the blood vessel. Therefore, the upper and lower vena cava must be reliably blocked.
[0066]
In addition, the pump is controlled so that the inflow circuit internal pressure does not become an excessive negative pressure to prevent sticking. Even if these safety measures are taken, a safety mechanism is provided in consideration of the possibility of air being mixed. The mixed air is detected by the bubble detection function of the ultrasonic flowmeter, and an alarm is sounded immediately, the pump speed is reduced, and the flow rate is reduced. However, it does not stop. Stopping the pump means interrupting the circulation, so an easy pump stop is not an appropriate response. An air detection sensor is also attached to the filter, and the pump is stopped immediately if air accumulates above a certain level. An air vent port is provided at the upper end of the filter, and a suction circuit is connected in advance and normally shut off. When air is detected by the bubble detection function or when air accumulates in the filter, the block to the suction circuit is released automatically or manually, and the air is removed from the circuit. The blood reservoir is also provided with an air vent port at the upper end so that air can be removed as necessary.
[0067]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, since the blood reservoir has a capacity | capacitance adjustment means and a capacity | capacitance capacity | capacitance detection means, control of extracorporeal circulation is easy and the extracorporeal circulation apparatus with which the burden of apparatus operation was reduced can be provided. In addition, the operation of the apparatus can be automated. Furthermore, by controlling the blood reservoir and the blood pump together, the device can be operated safely even when the driving flow rate of the blood pump is increased, and thus minimally invasive extracorporeal circulation is possible.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an extracorporeal circulation apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a fluid pressure-regulated blood reservoir according to an embodiment of the present invention.
FIG. 3 is a schematic diagram showing various fluid (hydraulic) pressure-regulated blood reservoir capacity adjusting devices (capacity regulating method) in an embodiment of the present invention.
FIG. 4 is a schematic diagram showing various fluid (hydraulic) pressure-type adjustable blood reservoir capacity adjusting devices (pump hydraulic pressure adjusting method) in an embodiment of the present invention.
FIG. 5 is a schematic diagram showing various mechanical volume control blood reservoirs according to an embodiment of the present invention.
FIG. 6 is a schematic diagram showing an outline of a separation type operation panel in the embodiment of the present invention.
FIG. 7 is a schematic diagram showing an air mixing prevention device according to an embodiment of the present invention.
FIG. 8 is a schematic view showing a conventional extracorporeal circulation apparatus.
[Explanation of symbols]
2 Devascularization
3 Blood reservoir
4 Heating and cooling device
5 Heat exchanger
6 Main pump
7 Artificial lung
8 Gas flow to the oxygenator
9 Filter
10 Blood vessels
11 Blood flow in the circuit
12 piston
13 Syringe
14 Bellows
15 Pusher plate
16 Blood chamber
17 Pressure regulation room
18 Diaphragm
19 Piston
20 syringe
21 Bellows
22 Pusher plate
23 Roller pump
24 Axial flow pump
25 Liquid storage chamber for liquid transfer
26 Separate operation panel
27 Transparent sheet
30 Blood flow
31 Ultrasonic flowmeter probe
32 filters
33 Optical sensor
34 Port for exhausting air
35 Suction circuit
36 Circuit breaker
37 In-circuit pressure measurement port
38a Drive device
38b Driving motor
39 Controller
40 Wiring

Claims (8)

In the extracorporeal circulation apparatus configured to arrange a predetermined element in the circuit and circulate blood in extracorporeal,
A blood pump,
A blood reservoir having a capacity detecting means for detecting the volume adjustment means, and the capacity of the order actively increase or decrease the capacity for storing,
A control means for controlling the volume of the blood reservoir via the capacity adjusting means, to which the output of the capacity detecting means is supplied, and for controlling the flow rate of the blood pump;
The blood reservoir has a blood chamber for storing blood, and a pressure regulation chamber provided adjacent to the blood chamber, provided in a lumen of a housing made of a hard material.
The blood chamber is a closed type in which the blood in the chamber does not come into contact with outside air, and is provided with a connecting tube for blood inflow and a connecting tube for blood outflow,
The pressure adjusting chamber is provided with a connecting pipe connected to the capacity adjusting means,
Adjacent portions of the blood chamber and the pressure regulation chamber are in contact via a flexible partition wall,
The volume adjusting means is configured to adjust the volume of the blood chamber by causing a liquid to flow into and out of the pressure adjusting chamber and deforming the partition wall,
It said capacitance detection means is configured to detect the capacity of the blood reservoir on the basis of the outflow Iriryou of the liquid to the pressure adjusting chamber that due to the volume adjustment means,
The control means may adjust the amount of extracorporeal blood circulation by controlling the capacity adjusting means to increase or decrease the capacity of the blood reservoir based on the detection value supplied from the capacity detecting means. An extracorporeal circulation device configured as described above.   The extracorporeal circulation apparatus according to claim 1, further comprising a circulation state detection unit that detects a circulation state in the circuit, wherein the control unit adjusts the extracorporeal circulation amount according to an output detected by the circulation state detection unit.   The extracorporeal circulation apparatus according to claim 2, wherein the circulation state detection means is a pressure sensor provided in the inflow portion.   The control means detects the suction of the blood removal part based on the information obtained from the circulatory state detection means, and when the suction is detected, reduces the rotation speed of the blood pump or reduces the capacity of the blood reservoir. The extracorporeal circulation apparatus according to claim 2 or 3, wherein the extracorporeal circulation apparatus is controlled.   The increase in the extracorporeal circulation flow rate is performed by at least one of the operation of increasing the rotation speed of the blood pump or decreasing the capacity of the blood reservoir, and the decrease in the extracorporeal circulation flow rate is decreasing the rotation speed of the pump or the The extracorporeal circulation apparatus according to claim 2, wherein the extracorporeal circulation apparatus is performed by at least one of operations for increasing the capacity of the blood reservoir.   The extracorporeal circulation apparatus according to any one of claims 1 to 5, further comprising means for generating a pulsatile flow in the circulation system by periodically increasing or decreasing the rotation speed of the blood pump.   The extracorporeal circulation apparatus according to any one of claims 1 to 6, further comprising means for generating a pulsating flow or vibration in the circulation system by periodically increasing or decreasing the capacity of the blood reservoir.   The extracorporeal circulation apparatus according to any one of claims 1 to 7, wherein at least a blood pump, a blood reservoir, an artificial lung, and a filter are integrally assembled among elements arranged in the circuit.

Images