JP7553950B2 - Auxiliary circulatory control device, auxiliary circulatory system - Google Patents

Description

The present invention relates to an auxiliary circulation control device and an auxiliary circulation system that are applied to an auxiliary circulation device that is connected to a living body and sends blood to an artificial lung using a blood pump, and exchanges blood with gas in the artificial lung.

As is well known, in cardiac surgery and the like, extracorporeal circulation (CPB) is performed as necessary in which the heart is stopped or placed in a nearly stopped state using an extracorporeal blood circulation device.
In such extracorporeal circulation (CPB), gas exchange in blood is carried out by an artificial lung (hereinafter sometimes referred to as a membrane lung, ML).

In extracorporeal circulation (CPB), for example, a gas monitoring device can be used to monitor whether blood gas exchange in the artificial lung (ML) is occurring properly (see, for example, Patent Document 1).

On the other hand, when treating patients with acute pneumonia (ARDS), the function of the natural lung (hereinafter sometimes referred to as NL) may be restored by using an artificial ventilator.
When an artificial ventilator is used, not only does the artificial ventilator not function adequately due to a decline in the function of the natural lung (NL), but there is also a concern that use of the artificial ventilator may actually result in a decline in the function of the natural lung.

Therefore, in the treatment of patients with acute pneumonia (ARDS), blood gas exchange is performed using auxiliary circulation (extracorporeal membrane oxygenation, hereinafter referred to as ECMO) in order to partially halt the vital lung function and allow the vital lungs to recover.
Specifically, an artificial lung (ML) and a vital lung (NL) coexist, and blood drawn from the patient is exchanged with gas in the artificial lung (ML) and then returned to the body, thereby allowing the function of the vital lung (NL) to be assisted by the artificial lung (ML).
Treatment using assisted circulation (ECMO) may be performed for a long period of time, for example, from several days to about one month.

In addition, during a patient's recovery, the degree of dependency on ECMO or weaning from ECMO must be reduced according to the patient's vital lung function, and it is inappropriate to reduce the level of ECMO more than necessary without taking this into consideration.

Patent No. 4562490

However, in blood gas exchange via ECMO, blood gas exchange occurs not only in the artificial lung (ML) but also in the native lung (NL), making it difficult to accurately determine whether blood gas exchange via ECMO is being performed appropriately.
In addition, management of the vital lung (NL) using an artificial ventilator relies on monitoring of ventilation volume and end-tidal carbon dioxide partial pressure, but it is not possible to manage all breathing in patients who are using assisted circulation (ECMO) for blood gas exchange.

Therefore, in treatment using ECMO, it is necessary to monitor whether blood gas exchange in the living body is appropriate by intermittently analyzing blood gases taken from the patient, and to understand whether blood gas exchange by ECMO, and therefore all of the patient's breathing by the vital lung (NL) and artificial lung (ML), is occurring appropriately, which places a heavy burden on medical staff.

Therefore, there is a demand for technology that can reduce the burden on medical staff in treatment using assisted circulation (ECMO) while enabling treatment using assisted circulation (ECMO) to be performed efficiently and safely.

The present invention has been made in consideration of the above circumstances, and aims to provide an auxiliary circulation control device and an auxiliary circulation system that are capable of calculating blood gas exchange status indicators (e.g., respiratory efficiency based on body weight, spontaneous rate, auxiliary circulation ratio, blood oxygenation status index, etc.) for an auxiliary circulation device connected to a living body, and efficiently performing at least one of the following:
1) To determine the appropriateness of the degree of dependency on the circulatory support (e.g., the need to increase the degree of dependency, or the possibility of decreasing the degree of dependency). 2) To decrease the degree of dependency on the circulatory support device. 3) To determine whether it is possible to wean the circulatory support device. 4) To wean the circulatory support device.

In order to solve the above problems, the present invention proposes the following means.
(1) A first aspect of the present invention is an auxiliary circulation control device that is connected to a living organism, sends blood removed from the living organism to an artificial lung using a blood supply pump, and controls an auxiliary circulation device that exchanges blood gas in the artificial lung in parallel with the living organism's lungs, and is characterized in having an artificial lung intake gas control unit that supplies gas to the artificial lung, and a blood supply pump flow rate control unit that controls the flow rate of blood sent to the artificial lung, and is further characterized by having a gas exchange amount control unit that changes the amount of gas exchange of blood in the artificial lung, and a blood gas exchange status index calculation unit that calculates a blood gas exchange status index in the living organism.

According to the auxiliary circulation control device of the present invention, since it has an artificial lung intake gas control unit that supplies blood to the artificial lung, a blood pump flow rate control unit that controls the flow rate of blood sent to the artificial lung, and a gas exchange amount control unit that changes the amount of blood gas exchange in the artificial lung, it is possible to operate the auxiliary circulation device while calculating a blood gas exchange status index (e.g., respiratory efficiency based on body weight, spontaneous rate, auxiliary circulation ratio, etc.) and checking the blood gas exchange status index. Specifically, for example, by checking the blood gas exchange status index that changes over time, it is possible to control the amount of blood gas exchange in the artificial lung and to determine whether or not to change the amount of blood gas exchange.
In addition, the metabolic state of the patient can be easily understood.

The artificial lung intake gas control unit controls the oxygen content of the artificial lung intake gas, and is capable of controlling at least one of the amount of artificial lung intake gas supplied and the oxygen concentration of the artificial lung intake gas.

In this specification, the blood gas exchange status index is an index capable of evaluating whether the blood gas exchange status in a living lung or an artificial lung is appropriate, and examples thereof include respiratory efficiency based on body weight, spontaneous respiratory rate, assisted circulation rate (ECMO Rate), blood oxygenation status index, and indexes that uniquely correspond to these.
In addition, examples of blood oxygenation status indicators include oxygen saturation in an artificial lung, oxygen saturation in a living body, hemoglobin concentration in blood, oxygen partial pressure in blood, etc., and other well-known indicators that indicate the degree of oxygenation of blood may also be applied.

In the specification, the amount of oxygen intake in an artificial lung or a living lung, and the amount of carbon dioxide discharged in an artificial lung or a living lung may be referred to as gas exchange parameters. In addition, well-known parameters such as the oxygen concentration (oxygen content, oxygen partial pressure), carbon dioxide concentration (carbon dioxide content, carbon dioxide partial pressure) and gas supply amount of a gas that can calculate these may also be applied. In addition, for example, a configuration may be used to calculate the content of other gases (e.g., anesthetic gas, etc.) contained in a breathing gas that can identify the content of carbon dioxide and oxygen.

When acquiring gas exchange parameters (e.g., oxygen intake) for oxygenating blood in a living lung, the oxygen concentration of the respiratory gas during natural breathing (e.g., when using an oxygen mask) may be applied in addition to the respiratory gas using an artificial ventilator.

Furthermore, for example, carbon dioxide (CO ₂ ) concentration and oxygen (O ₂ ) concentration may be referred to as oxygen content parameters as they are parameters relating to the content of gas for oxygenating blood.

Also, changing the amount of gas exchange refers to an operation that includes at least one of decreasing the amount of gas exchange or increasing the amount of gas exchange.

(2) In the auxiliary circulation control device described in (1) above, the blood gas exchange status index calculation unit may perform calculations at set time intervals.

According to the auxiliary circulation control device of the present invention, the control unit performs calculations at set time intervals, making it possible to grasp the trend of the blood gas exchange status index when the amount of blood gas exchange is changed.
In addition, by accumulating data in chronological order, blood gas exchange status indicators can be accurately grasped.

The set time interval may be set manually or automatically in accordance with the measurement interval of a sensor or the like, and can be set arbitrarily. It may also be calculated and displayed in real time or with a certain time delay.

(3) In the auxiliary circulation control device described in (1) or (2) above, the gas exchange amount control unit may change at least one of the oxygen content of the artificial lung intake gas supplied to the artificial lung and the flow rate of blood sent to the artificial lung when changing the gas exchange amount of blood in the artificial lung.

According to the auxiliary circulation control device of the present invention, when changing the gas exchange volume of blood in the artificial lung, the gas exchange volume control unit changes at least one of the oxygen content of the artificial lung intake gas supplied to the artificial lung and the flow rate of blood sent to the artificial lung, thereby easily and stably changing the oxygen intake of blood in the artificial lung.
As a result, the oxygenation state of the blood in the artificial lung can be changed efficiently.

(4) In the auxiliary circulation control device described in (1) or (2) above, the gas exchange amount control unit may control the amount of blood gas exchange in the artificial lung based on the blood gas exchange status index calculated by the blood gas exchange status index calculation unit.

According to the auxiliary circulation control device of the present invention, the gas exchange volume control unit controls the blood gas exchange volume in the artificial lung based on the blood gas exchange status index calculated by the blood gas exchange status index calculation unit, so that the blood gas exchange volume can be controlled in accordance with the status of the blood gas exchange status index.
(5) The auxiliary circulation control device described in any one of (1) to (4) above may further include a blood gas exchange status determination unit that determines whether the blood gas exchange status index is within a set numerical range.

The auxiliary circulation control device according to the present invention is provided with a blood gas exchange status determination unit, which determines whether the blood gas exchange status index when the amount of blood gas exchange in the artificial lung is changed is within a set numerical range. Therefore, for example, it is possible to accurately determine whether it is appropriate to reduce the degree of dependency on auxiliary circulation, or whether it is necessary to increase the degree of dependency on auxiliary circulation (for example, by detecting that the blood gas exchange status index of the entire living body increases when the amount of gas exchange through auxiliary circulation is increased, and thus determining the need to increase the degree of dependency on auxiliary circulation).

(6) In the auxiliary circulation control device described in (5) above, the blood gas exchange status determination unit may be configured to calculate the blood gas exchange status index when the amount of blood gas exchange in the artificial lung is changed, and determine whether a reduction in dependency on auxiliary circulation is appropriate based on whether the blood gas exchange status index is within a set numerical range due to a reduction in auxiliary circulation performed by the artificial lung.

According to the auxiliary circulation control device of the present invention, the blood gas exchange status determination unit calculates the blood gas exchange status index when the amount of blood gas exchange in the artificial lung is changed, and determines whether it is appropriate to reduce the dependence on auxiliary circulation based on whether the blood gas exchange status index is within a set numerical range due to the reduction in auxiliary circulation performed by the artificial lung, thereby making it possible to efficiently determine whether it is appropriate to reduce the dependence on auxiliary circulation based on the blood gas exchange status.
As a result, it is possible to efficiently check whether the dependency on auxiliary circulation can be reduced, check whether auxiliary circulation can be weaned, and wean the auxiliary circulation.

(7) In the auxiliary circulation control device described in any one of (1) to (6) above, the gas exchange amount control unit is configured to be able to change the amount of blood gas exchange in the artificial lung according to a preset program, and the blood gas exchange status index calculation unit may calculate the blood gas exchange status index when the gas exchange amount control unit changes the amount of blood gas exchange in the artificial lung according to the program.

According to the auxiliary circulation control device of the present invention, the gas exchange amount control unit is configured to be able to change the amount of blood gas exchange in the artificial lung according to a preset program, and the blood gas exchange status index calculation unit calculates the blood gas exchange status index when the amount of blood gas exchange in the artificial lung is changed according to the program, so that the blood gas exchange amount can be appropriately changed by the gas exchange amount control unit while checking the blood gas exchange status index.

(8) In the auxiliary circulation control device described in (7) above, the gas exchange amount control unit may be configured to reduce the amount of gas exchange of blood in the artificial lung in correspondence with the recovery time during which the biological lung becomes less dependent on the auxiliary circulation when changing the amount of gas exchange of blood in the artificial lung.

According to the auxiliary circulation control device of this invention, when changing the amount of gas exchange of blood in the artificial lung, the gas exchange amount control section is configured to reduce the amount of gas exchange of blood in the artificial lung in correspondence with the recovery time during which the dependency of the living lung on the auxiliary circulation decreases. Therefore, the dependency on the auxiliary circulation can be changed while checking the recovery of the living lung function, thereby decreasing the dependency on the auxiliary circulation or smoothly disconnecting the auxiliary circulation device.

(9) In the auxiliary circulation control device described in (8) above, the gas exchange amount control unit changes the amount of gas exchange of blood in the artificial lung, and when a preset condition for stopping the operation of reducing the dependency on auxiliary circulation is detected, the blood flow rate sent to the artificial lung and the oxygen content of the artificial lung intake gas supplied to the artificial lung may be restored to a preset state.

According to the auxiliary circulation control device of this invention, the gas exchange amount control unit changes the gas exchange amount of blood in the artificial lung, and when a preset condition for stopping the operation of reducing the dependency on auxiliary circulation is detected, the blood flow rate sent to the artificial lung and the oxygen content of the artificial lung intake gas supplied to the artificial lung are restored to a preset state, so that the degree of dependency on auxiliary circulation in the living body can be safely changed.

Here, the condition for stopping the operation of reducing the dependency on auxiliary circulation may be any of conditions for releasing, interrupting, or stopping the operation of reducing the dependency on auxiliary circulation.
Furthermore, the preset state is not limited to the state when control to change the gas exchange amount is started, but may be a preset numerical value, or a numerical value when the blood gas exchange situation is determined to be appropriate, or a numerical value set at a certain ratio or difference relative to these.

(10) The auxiliary circulation control device described in any one of (7) to (9) above may output an alarm when the blood gas exchange status index calculated by the blood gas exchange status index calculation unit falls outside a set numerical range.

According to the auxiliary circulation control device of the present invention, the blood gas exchange status determination outputs an alarm when the blood gas exchange status index falls outside a set numerical range while the program is being executed, so that any abnormality that occurs can be identified at an early stage.
As a result, the degree of dependency on assisted circulation in the living body can be safely changed.

(11) A second aspect of the present invention is an auxiliary circulation system comprising an auxiliary circulation control device described in any one of (1) to (10) above.

The auxiliary circulation system of this invention makes it possible to efficiently grasp blood gas exchange status indicators when the amount of blood gas exchange by the artificial lung changes.

The auxiliary circulation control device and auxiliary circulation system of the present invention can efficiently grasp the change in the blood gas exchange status index when the amount of blood gas exchange by the artificial lung changes.

FIG. 1 is a conceptual diagram for explaining the schematic configuration of auxiliary circulation (VV ECMO) according to a first embodiment of the present invention. FIG. 1 is a conceptual diagram for explaining an outline of blood circulation in a patient to which auxiliary circulation (VV ECMO) according to the first embodiment is not applied. FIG. 1 is a conceptual diagram for explaining an outline of blood circulation in a patient to whom auxiliary circulation (VV ECMO) according to the first embodiment is applied. FIG. 1 is a block diagram illustrating a schematic configuration of an auxiliary circulation control device according to a first embodiment. 4 is a flowchart showing an outline of a calculation procedure in an artificial lung carbon dioxide discharge amount calculation unit, explaining the schematic configuration of the auxiliary circulation control device according to the first embodiment. 1 is a flowchart showing an outline of a calculation procedure in an artificial respirator carbon dioxide emission calculation unit, explaining the general configuration of the auxiliary circulation control device according to the first embodiment. 4 is a flowchart showing an outline of a calculation procedure of an auxiliary circulation ratio in an auxiliary circulation ratio calculation unit, illustrating a schematic configuration of the auxiliary circulation control device according to the first embodiment. 1 is a flowchart showing an outline of a calculation procedure of respiratory efficiency (blood gas exchange status index) based on body weight in a blood gas exchange status index calculation unit, illustrating the general configuration of the auxiliary circulation control device in the first embodiment. FIG. 1 is a flow chart illustrating an outline of a procedure for determining a blood gas exchange status in determining a blood gas exchange status, illustrating a schematic configuration of an auxiliary circulation control device according to a first embodiment. 4 is a flowchart showing an outline of an example of a gas exchange volume steady-state control procedure, illustrating the general configuration of the auxiliary circulation control device according to the first embodiment. 4 is a flowchart showing an outline of an example of a gas exchange rate fluctuation control procedure, illustrating the general configuration of the auxiliary circulation control device according to the first embodiment. 1 is a conceptual diagram illustrating the schematic configuration of a liquid crystal touch panel connected to the auxiliary circulation control device according to the first embodiment. FIG. FIG. 11 is a conceptual diagram for explaining the schematic configuration of auxiliary circulation (VA ECMO) according to a second embodiment of the present invention. FIG. 11 is a conceptual diagram for explaining an outline of blood circulation in a patient to whom auxiliary circulation (VA ECMO) according to the second embodiment is applied.

First Embodiment
Hereinafter, the auxiliary circulation (VV ECMO) according to the first embodiment of the present invention will be described with reference to FIGS.
Fig. 1 is a conceptual diagram for explaining the schematic configuration of the auxiliary circulation (V-V ECMO) according to the first embodiment. The dotted lines in Fig. 1 indicate electric cables (some paths are omitted) connecting the auxiliary circulation control device 100 to each sensor, the artificial lung gas supply device, and the centrifugal pump driver.

In the figure, reference numeral 10 denotes an auxiliary circulation system (blood circulation circuit) in auxiliary circulation (V-V ECMO), reference numeral 100 denotes an auxiliary circulation control device, reference numeral 115 denotes a centrifugal pump (blood supply pump), reference numeral 120 denotes an artificial lung, reference numeral 140 denotes an artificial ventilator, reference numeral 148 denotes a pulse oximeter (blood oxygenation index measuring device), and reference numeral 180 denotes an LCD touch panel.
Hereinafter, the auxiliary circulation system (blood circulation circuit) will be referred to as the auxiliary circulation system (VV ECMO).

The first embodiment is an example in which, as shown in FIG. 1, for example, an auxiliary circulation system (VV ECMO) 10 and an artificial ventilator 140 are connected to a patient (living body).
In the first embodiment, as shown in FIG. 1, for example, an auxiliary circulation control device 100, an auxiliary circulation system (V-V ECMO) 10, a liquid crystal touch panel 180, an artificial ventilator 140, and a pulse oximeter (blood oxygenation index measuring device) 148 are connected to a patient (living body) P.

As shown in FIG. 1, the auxiliary circulation system (V-V ECMO) 10 is configured to circulate blood drawn from a vein V1 of a patient (living body, human body) P using a centrifugal pump (blood supply pump) 115, to subject the blood to gas exchange in an artificial lung 120, and to return the blood to the vein V1 of the patient P.
In addition, a patient (living body, human body) P is connected to an artificial ventilator 140, and inhales intake gas supplied from the artificial ventilator 140 to perform artificial respiration in which blood is oxygenated in the living lungs (NL).

1, the auxiliary circulation system (V-V ECMO) 10 includes, for example, a blood removal line 111, a blood supply line 112, a blood return line 113, a recirculation line 114, a centrifugal pump (blood supply pump) 115, a flow rate sensor 116, an oxygen saturation sensor 117, a blood supply autoclamp 118, a recirculation clamp 119, and an artificial lung 120. In addition, the centrifugal pump 115 is supplied with power from, for example, a centrifugal pump driver 115D.
In this embodiment, the centrifugal pump (blood pump) 115 and the artificial lung 120 constitute an auxiliary circulatory system.

For example, as shown in FIG. 1, the blood removal line 111, centrifugal pump 115, blood supply line 112, artificial lung main body 121, and blood return line 113 are arranged in this order relative to patient P, so that blood removed from patient P circulates in this order and is returned to patient P in a steady state.

The blood removal line 111 includes, for example, a first blood removal line 111A connected to the upstream side (patient P side) and a second blood removal line 111B connected to the downstream side (centrifugal pump side).
The blood removal line 111 transfers the blood removed from the patient P to the centrifugal pump 115.
The blood supply line 112 transports blood pumped from, for example, a centrifugal pump 115 to an oxygenator 120 .

The blood return line 113 includes, for example, a first return line 113A connected to the upstream side (the artificial lung side) and a second return line 113B connected to the downstream side (the patient P side).
The return line 113 transfers (returns) the blood sent out from the oxygenator 120 to the vein V1 of the patient (living body) P.
Further, a flow rate sensor 116 is disposed in the first return line 113 .

The recirculation line 114 connects, for example, between the first return line 113A and the second return line 113B of the blood return line 113, and between the first blood removal line 111A and the second blood removal line 111B of the blood removal line 111.

The blood removal line 111, blood supply line 112, return line 113, and recirculation line 114 are made of tubes made of, for example, a flexible resin material.

As shown in FIG. 1 , the centrifugal pump (blood supply pump) 115 has an inflow side connected to the blood removal line 111 and an outflow side connected to the blood supply line 112. For example, by rotating an impeller blade using an AC servo motor or a DC servo motor, the centrifugal pump 115 sucks blood removed from the patient P via the blood removal line 111 and transfers the blood to the artificial lung 120 via the blood supply line 112.
Further, the centrifugal pump 115 is configured to perform feedback control by detecting the flow rate (flow velocity) with a flow rate sensor 116 by operating a flow rate setting switch (not shown), for example.

As shown in FIG. 1, the blood supply autoclamp 118 is disposed, for example, in the return line 113. More specifically, it is disposed in the second return line 113B, and is configured, for example, to manually operate an actuator to close or open the blood supply autoclamp 118 using a clamp unit.

As shown in FIG. 1, the recirculation clamp 119 is disposed, for example, in the recirculation line 114, and is configured, for example, to manually operate the clamp portion with an actuator to close or open the recirculation line 114.

When the blood supply autoclamp 118 opens the second return line 113B, the recirculation clamp 119 closes the recirculation line 114, and the drawn blood circulates to the patient P via the blood supply line 111, the blood supply line 112, and the return line 113.

In addition, for example, in an emergency, when the blood supply autoclamp 118 blocks the second return line 113B, the recirculation clamp 119 opens the recirculation line 114, and the drawn blood circulates between the second blood supply line 111B, the blood supply line 112, the first return line 113A, and the recirculation line 114. This prevents blood from circulating and stagnating even when the gas supply to the artificial lung (ML) 120 is stopped, thereby preventing blood clotting.

The oxygen saturation sensor (blood oxygenation indicator sensor) 117 includes, for example, a removed blood oxygen saturation sensor arranged in the second blood removal line 111B, and a return blood oxygen saturation sensor arranged in the first return line 113A.
For simplicity, only the perfusion blood oxygen saturation sensor is indicated by reference numeral 117 in FIG.

In this embodiment, the oxygen saturation sensor (perfusion blood oxygen saturation sensor) 117 is connected to the auxiliary circulation control device 100 by a cable (not shown) and detects the oxygen saturation and hemoglobin content in the blood sent out from the artificial lung main body 121 and flowing through the first perfusion line 113A, and transmits the results to the auxiliary circulation control device 100.

In this embodiment, the oxygen saturation sensor 117 is configured to detect an oxygenation index (oxygenation degree, blood oxygenation index) of hemoglobin in blood by, for example, infrared rays.
The configuration of the oxygen saturation sensor 117 can be set arbitrarily within a range capable of detecting the degree of blood oxygenation, and various known sensors capable of measuring a blood oxygenation index may be applied.

As shown in Figure 1, the artificial lung 120 includes, for example, an artificial lung main body 121, an artificial lung intake line 123, an artificial lung exhaust line 124, an artificial lung intake gas sensor 125, and an artificial lung exhaust gas sensor 126, and is connected to an artificial lung gas supply device 122.
The blood flowing through the auxiliary circulation system (VV ECMO) 10 is oxygenated.

The oxygenator body 121 is equipped with, for example, a hollow fiber membrane or a flat membrane having excellent gas permeability.
In the hollow fiber membrane or flat membrane, oxygen in the supplied gas moves to the blood side, and carbon dioxide dissolved in the blood moves to the gas side supplied to the oxygen lung, so that the blood is exchanged with the gas. The oxygen lung body 121 is integrally formed with a heat exchanger for adjusting the temperature of the blood, for example.
The configuration of the oxygenator body 121 can be arbitrarily set as long as gas exchange with blood is possible.

The artificial lung gas supply device 122 supplies gas adjusted to an oxygen (O ₂ ) concentration suitable for gas exchange to the artificial lung main body 121. In this embodiment, for example, the oxygen (O ₂ ) concentration of the gas is adjusted to 100%.

The artificial lung intake line 123 includes, for example, a first intake line 123A connected to the artificial lung gas supply device 122 side, and a second intake line 123B connected to the artificial lung main body 121 side.
The artificial lung intake line 123 transfers the artificial lung intake gas sent out from the artificial lung gas supply device 122 to the artificial lung main body 121.

The artificial lung exhalation line 124 discharges the exhaled air discharged from the artificial lung main body 121 to the outside of the system.
Moreover, the artificial lung inhalation line 123 and the artificial lung exhalation line 124 are configured by tubes made of, for example, a flexible resin material.

In this embodiment, the oxygenator inhalation gas sensor 125 is, for example, a carbon dioxide (CO ₂ ) sensor.
Moreover, the oxygenator intake gas sensor 125 is disposed in the oxygenator intake line 123. Specifically, the oxygenator intake gas sensor 125 is disposed between the first oxygenator intake line 123A and the second oxygenator intake line 123B.
Then, the carbon dioxide (CO2) concentration of the inhaled air sent to the oxygenator main body 121 via the oxygenator inhalation line 123 is detected.

In this embodiment, the artificial lung exhaled gas sensor 126 is, for example, a carbon dioxide (CO ₂ ) sensor.
Moreover, the artificial lung exhalation gas sensor 126 is disposed in the artificial lung exhalation line 124. Specifically, the artificial lung exhalation gas sensor 126 is disposed at the downstream end of the artificial lung exhalation line 124.
Then, the concentration of carbon dioxide (CO ₂ ) contained in the expired air discharged from the oxygenator main body 121 via the oxygenator expired air line 124 is detected.

The configuration of the artificial lung inhalation gas sensor 125 and the artificial lung exhalation gas sensor 126 can be set arbitrarily, for example, an oxygen ( _O2 ) sensor may be used instead of a carbon dioxide ( _CO2 ) sensor. Also, the artificial lung inhalation gas sensor 125 and the artificial lung exhalation gas sensor 126 may be various known sensors that can detect concentration parameters such as partial pressure of carbon dioxide ( _CO2 ) that can specify the carbon dioxide ( _CO2 ) concentration in the inhaled and exhaled air.

In addition, for example, a sampling circuit (not shown) may be provided in the artificial lung intake line 123 and the artificial lung expiration line 124, and the sampling lines may be switched between the artificial lung intake line 123 and the artificial lung expiration line 124, so that a single gas sensor serves as both the artificial lung intake gas sensor 125 and the artificial lung expiration gas sensor 126.

As shown in FIG. 1 , the ventilator 140 is connected to a patient P via, for example, a ventilator inhalation line 141 and a ventilator exhalation line 143 .
The ventilator 140 is configured to supply ventilator gas with an increased concentration of oxygen (O ₂ ) to the patient (living body) P, thereby assisting the patient P in efficiently carrying out gas exchange with the blood.

The configuration of the ventilator 140 can be set arbitrarily, but in this embodiment, for example, it is configured to include a gas circuit with a pressure reducing valve, an inhalation valve, an exhalation valve, a pressure control circuit, a flow control circuit, and a display unit that also serves as an input device (I/O).

The ventilator inhalation line 141 transports the ventilator inhalation air sent out from the ventilator 140 to the patient P's vital lungs (NL).
Also, as shown in FIG. 1, for example, an artificial ventilator intake gas sensor 142 is arranged in the artificial ventilator intake line 141, which is capable of detecting the carbon dioxide (CO ₂ ) concentration of the intake air supplied from the artificial ventilator 140 to the patient P via the artificial ventilator intake line 141.

The ventilator expiratory line 143 transports the expired air discharged from the patient P's vital lungs (NL) to the ventilator 140 .
Also, as shown in FIG. 1, for example, an artificial ventilator exhalation gas sensor 144 is arranged in the artificial ventilator exhalation line 143, which is capable of detecting the carbon dioxide (CO ₂ ) concentration in the exhaled air after it is used to oxygenate the blood exhaled by the patient P and transported to the artificial ventilator 140 via the artificial ventilator exhalation line 143.

Hereinafter, the operation of the auxiliary circulation system (VV ECMO) will be described with reference to FIGS.
Fig. 2 is a schematic diagram for explaining the outline of blood circulation of a patient (living body) P to which an auxiliary circulatory system (V-V ECMO) is not applied, and Fig. 3 is a conceptual diagram for explaining the outline of blood circulation of a patient P to which an auxiliary circulatory system (ECMO) is applied. Note that in Figs. 2 and 3, the blood flow between the heart and the living body's lungs is omitted.
2 and 3, the white arrows indicate the flow of blood after gas exchange, and the solid arrows indicate the flow of blood before gas exchange.

[When an extracorporeal membrane oxygenation (ECMO) system is not used]
First, blood circulation in the case where an auxiliary circulatory system (ECMO) is not applied will be described with reference to FIG.
When an ECMO system is not used, blood circulation in a patient (living body) P is as shown in FIG. 2, in which blood with an oxygen content (oxygen content parameter) _CaO2 and an arterial blood oxygen saturation (blood oxygenation status index) _SaO2 after being oxygenated in the living lungs (NL) is pumped by the heart through the artery A1 to living tissues PS throughout the body.

Then, the blood sent to the living tissue PS becomes blood (venous blood) with a reduced oxygen content (oxygen content parameter) _CvO2 and oxygen saturation (blood oxygenation status index) _SvO2 , as some of the oxygen ( _O2 ) in the blood is consumed through metabolism and carbon dioxide ( _CO2 ) is produced.
It then flows back to the heart and the vital lungs (NL) via the vein V1.
In this blood circulation, for example, blood flows through the artery A1 and the vein V1 at the same flow rate Q _CO .
Here, the oxygen saturation of venous blood (blood oxygenation status index) _SvO2 may be, for example, a measurement value of a Swan-Ganz catheter. Also, the flow rate _QCO may be measured using a measurement value of a Swan-Ganz catheter, blood pressure waveform analysis, ultrasonic echo, MRI, etc.

[When the auxiliary circulation system (V-V ECMO) 10 is applied]
Next, blood circulation in the case where an auxiliary circulatory system (ECMO) is applied will be described with reference to FIG.
As shown in FIG. 3, in a patient (living body) P to whom an auxiliary circulation system (V-V ECMO) 10 is being applied, the arterial blood oxygen content CaO ₂ , arterial blood oxygen saturation (blood oxygenation status index) SaO ₂ , and flow rate (spontaneous cardiac output) Q _CO ) oxygenated in the living lungs (NL) are sent by the heart through the artery A1 to living tissues PS throughout the body.

In addition, the venous blood (oxygen content CvO ₂ , oxygen saturation (index of blood oxygenation status) SvO ₂ , flow rate (same amount as the native cardiac output) Q _CO ) that has undergone gas exchange (metabolism) in the biological tissue PS flows toward the heart and the biological lungs via the vein V1, and blood at a flow rate Q _ECMO is withdrawn at the blood withdrawal point P1 and flows into the artificial lung (ML) of the auxiliary circulation system (V-V ECMO) 10.

On the other hand, blood that is not removed at the blood removal point P at a flow rate Q _COP (= Q _CO - Q _ECMO ) flows directly through the vein V1 toward the heart.
Q _RE shown in FIG. 3 indicates the flow rate of blood recirculated in the auxiliary circulation (VV ECMO) that is oxygenated and returned to the vein V1 and then flows again into the artificial lung (ML).

The removed blood is sent to the artificial lung (ML), where it is oxygenated through gas exchange, and returned to the vein V1 at a return point P2.
The blood returned to the vein V1 at the return point P2 is mixed with the blood with oxygen content _CvO2 and oxygen saturation _SvO2 that has flowed through the vein V1, and becomes mixed venous blood with oxygen content _CvO2 (NL), oxygen saturation (blood oxygenation status index) _SvO2 (NL), and flow rate _QCO , which is then sent to the living lung (NL).
The blood is then oxygenated in the living lungs (NL) to become blood with an oxygen content of CaO ₂ and an arterial blood oxygen saturation of SaO ₂ , and is sent to the artery A1.

At this time, the blood sent to the artery A1 is oxygenated, for example, in the artificial lung (ML) with an oxygen intake V'O2 (ML), and in the natural lung (NL) with oxygen (O2) with an oxygen intake V'O2 (NL).

The contribution of the vital lung (NL) to blood gas exchange can be expressed, for example, by the spontaneous rate:
Spontaneous rate = oxygen intake V'O2 (NL) in the natural lung (NL) / (oxygen intake V'O2 (ML) in the artificial lung (ML) + oxygen intake V'O2 (NL) in the natural lung (NL))

The contribution of the extracorporeal circulation (ECMO) in a living body can be expressed by the extracorporeal circulation rate (ECMO rate). For example, when focusing on the amount of oxygen intake, the rate is expressed as follows:
Auxiliary circulation ratio (ECMO Rate)
= (oxygen intake amount V'O ₂ (ML) in artificial lung (ML)) / (oxygen intake amount V'O ₂ (ML) in artificial lung (ML) + oxygen intake amount V'O ₂ (NL) in natural lung (NL))
It becomes.
Here, the amount of oxygen intake V'O ₂ (NL) in the living lungs (NL) can be obtained as the amount of oxygen contained in the breath of the patient (living body).

On the other hand, when the ECMO rate is expressed in terms of carbon dioxide emissions, it is as follows:
Auxiliary circulation ratio (ECMO Rate)
= (V'CO ₂ (ML) of carbon dioxide discharged in artificial lung (ML))/(V'CO ₂ (ML) of carbon dioxide discharged in artificial lung (ML)+V'CO ₂ (NL) of carbon dioxide discharged in natural lung (NL))
It becomes.
Here, the carbon dioxide discharge amount V'CO ₂ (NL) in the living lung (NL) can be obtained as the carbon dioxide content contained in the respiratory air of the patient (living body).

In addition, regarding the blood circulation shown in FIG. 3, it is possible to confirm the state of blood gas exchange by calculating, for example, the following formulas (101) to (106).
If the oxygen transport volume of arterial blood is expressed as arterial blood oxygen transport volume _DaO2 and the oxygen transport volume of venous blood is expressed as venous blood oxygen transport volume _DvO2 , the oxygen intake volume _V'O2 in the artificial lung (ML) and the native lung (NL) and the amount of oxygen consumed in biological tissues [arterial blood oxygen transport volume _DaO2 - venous blood oxygen transport volume _DvO2 ] are expressed by formula (101).

数式（１０１）で示されたV'Ｏ_２（ＮＬ）＋V'Ｏ_２（ＭＬ）＝ＤａＯ_２－ＤｖＯ_２に着目して変形すると、以下の数式（１０２）が成立する。 If the venous blood oxygen transport rate is _DvO2 , the mass of oxygen is conserved during oxygen transfer, and the following equation (101) holds:

When formula (101) is rearranged in consideration of V'O ₂ (NL)+V'O ₂ (ML)=DaO ₂ -DvO ₂ , the following formula (102) is obtained.

また、図２に示す静脈Ｖ１を流れる血液の酸素運搬量ＤｖＯ_２は、以下の数式（１０３）で表わすことができる。

Further, the oxygen transport amount DvO2 of the blood flowing through the vein V1 shown in FIG. ₂ can be expressed by the following formula (103).

一方、人工肺（ＭＬ）における酸素摂取量V’Ｏ_２（ＭＬ）、補助循環量Ｑ_ＥＣＭＯ、人工肺（ＭＬ）で酸素化された血液の酸素含有量ＣａＯ_２（ＭＬ）、人工肺（ＭＬ）で酸素化される前の酸素含有量ＣｖＯ_２（ＭＬ）とすると、酸素含有量ＣａＯ_２（ＭＬ）は、以下の数式（１０４）で表わされる。

On the other hand, if the oxygen intake in the artificial lung (ML) is _V'O2 (ML), the auxiliary circulation volume _QECMO is the oxygen content _CaO2 (ML) of blood oxygenated in the artificial lung (ML), and the oxygen content _CvO2 (ML) before oxygenation in the artificial lung (ML), the oxygen content _CaO2 (ML) is expressed by the following formula (104).

そして、数式（１０２）の右辺の第２項に数式（１０３）を代入し、第３項に数式（１０４）を代入すると、動脈Ａ１を流れる自己心拍出量Ｑ_ＣＯの動脈血の血酸素運搬量ＤａＯ_２は、以下の数式（１０５）のように示される。

Then, by substituting formula (103) into the second term on the right side of formula (102) and substituting formula (104) into the third term, the blood oxygen transport rate _DaO2 of the arterial blood flowing through the artery A1 at the intrinsic cardiac output _QCO is given by the following formula (105).

また、生体全体の二酸化炭素総排出量V'ＣＯ_２は、人工肺（ＭＬ）の二酸化炭素排出量V'ＣＯ_２（ＭＬ）と、生体肺（ＮＬ）の二酸化炭素排出量V'ＣＯ_２（ＮＬ）の和に等しいので、数式（１０５）の左辺を生体全体の二酸化炭素総排出量V'ＣＯ_２で除すとともに、右辺を（生体肺（ＮＬ）の二酸化炭素排出量V'ＣＯ_２（ＮＬ）＋人工肺（ＭＬ）で示した二酸化炭素排出量V'ＣＯ_２（ＭＬ））で除すと、以下の数式（１０６）で表わすことができる。

In addition, the total amount of carbon dioxide emission from the entire organism _V'CO2 is equal to the sum of the amount of carbon dioxide emission from the artificial lung (ML) _V'CO2 (ML) and the amount of carbon dioxide emission from the natural lung (NL) _V'CO2 (NL). Therefore, by dividing the left side of equation (105) by the total amount of carbon dioxide emission from the entire organism _V'CO2 and by dividing the right side by (the amount of carbon dioxide emission from the natural lung (NL) _V'CO2 (NL) + the amount of carbon dioxide emission from the artificial lung (ML) _V'CO2 (ML)), it can be expressed as the following equation (106).

次に、酸素運搬量ＤａＯ_２を二酸化炭素（ＣＯ_２）総排出量V'ＣＯ_２（＝V'ＣＯ_２（ＮＬ）＋V'ＣＯ_２（ＭＬ））で除した数式（１０６）で算出される値が一定の値より大きいときには安全な循環動態と考えられるので、その値を閾値Ｖ_{ａｌａｒｍ}（管理目標値）として設定すると、ＤａＯ_２/ V'ＣＯ_２＞Ｖ_{ａｌａｒｍ}と表すことができる。そして、数式（１０６）の右辺に着目すると、以下に示す数式（１０７）が成立する。

Next, when the value calculated by dividing the amount of oxygen transport _DaO2 by the total amount of carbon dioxide ( _CO2 ) discharge _V'CO2 (= _V'CO2 (NL) + _V'CO2 (ML)) using formula (106) is greater than a certain value, it is considered that the circulatory dynamics is safe, and if this value is set as the threshold value V _alarm (target management value), it can be expressed as _DaO2 / _V'CO2 > V _alarm . Then, focusing on the right side of formula (106), the following formula (107) is established.

Here, the left side of equation (106) (DaO ₂ /V'CO ₂ ) represents the ratio (supply and demand) in gas exchange in the blood, and is calculated by monitoring the metabolism of patient P.
The oxygen transport rate _DaO2 corresponds to the oxygen supply, and the total carbon dioxide excretion _V'CO2 corresponds to the oxygen consumption. For the survival of an organism, the supply must be greater than the consumption; therefore, it is necessary to satisfy the following formula (107).

Note that V _alarm (target management value) shown in formula (107) is a threshold value (setting value) set for each patient P, and can be set based on, for example, blood gas exchange status indexes of the patient P (respiratory efficiency based on body weight, spontaneous rate, auxiliary circulation ratio (ECMO Rate), etc.) and blood oxygenation status indexes (oxygen saturation of the artificial lung, oxygen saturation of the living body, hemoglobin concentration of the blood, oxygen partial pressure of the blood, etc.), and is generally set empirically by a doctor.
As a result, by visualizing whether DaO ₂ /V'CO ₂ exceeds V _alarm (target value for management), management for each patient becomes possible.

数式（１０７）を、補助循環流量Ｑ_ＥＣＭＯに着目して変形すると、以下の数式（１０８）が得られる。

When equation (107) is modified with attention to the auxiliary circulation flow rate Q _ECMO , the following equation (108) is obtained.

ここで、ＣａＯ_２＝（（１．３４×Ｈｂ×ＳａＯ_２）／１００）＋０．００３１×ＰａＯ_２
であり、右辺第２項は第１項と比較して微少量であることから、右辺第２項を省略すると、
ＣａＯ_２ ≒（（１．３４×Ｈｂ×ＳａＯ_２）／１００）で表すことができる。したがって、数式（１０８）は、数式（１０９）のように表すことができる。

Here, _CaO2 = ((1.34 x Hb x _SaO2 )/100) + 0.0031 x _PaO2
Since the second term on the right side is a small amount compared to the first term, if the second term on the right side is omitted,
CaO ₂ ≈((1.34×Hb×SaO ₂ )/100). Therefore, formula (108) can be expressed as formula (109).

よって、数式（１０９）に基づいて、生体肺（ＮＬ）、人工肺（ＭＬ）の二酸化炭素の排出量の演算結果V’ＣＯ_２（ＮＬ）、V’ＣＯ_２（ＭＬ）、静脈血酸素飽和度ＳｖＯ_２、生体肺（ＮＬ）の酸素摂取量V’Ｏ_２（ＮＬ）、人工肺前後の酸素飽和度ＳｖＯ_２（ＭＬ）、ＳａＯ_２（ＭＬ）、静脈血酸素飽和度ＳｖＯ_２、及び自己心拍出量Ｑ_ＣＯから、各患者がＶ_{ａｌａｒｍ}（管理目標値）を満足するために必要な補助循環流量Ｑ_ＥＣＭＯを算出することが可能である。

Therefore, based on formula (109), it is possible to calculate the auxiliary circulating flow rate _QECMO required for each patient to satisfy V alarm (target management value) from the calculation results V'CO ₂ (NL), V'CO ₂ (ML) of carbon _dioxide discharge from the vital lung (NL) and artificial lung (ML), venous blood oxygen saturation SvO ₂ , oxygen intake amount V'O ₂ (NL) of the vital lung (NL), oxygen saturation before and after the artificial lung SvO ₂ (ML), SaO ₂ (ML), venous blood oxygen saturation SvO ₂ , and native cardiac output _QCO .

These indices that can be calculated using formulas (101) to (106) may be calculated appropriately in the auxiliary circulation control device 100 described below, and displayed in the control of the auxiliary circulation control device 100 or on the liquid crystal touch panel 180.

Next, the schematic configuration of the auxiliary circulation control device 100 and the liquid crystal touch panel 180 will be described with reference to Figs. 4 to 12. Fig. 4 is a block diagram explaining the schematic configuration of the auxiliary circulation control device according to the first embodiment, and Figs. 5 to 11 are flow charts outlining the calculation procedure and control procedure in the auxiliary circulation control device. Also, Fig. 12 is a conceptual diagram explaining the schematic configuration of the liquid crystal touch panel connected to the auxiliary circulation control device.

The configuration of the auxiliary circulation control device 100 and the liquid crystal touch panel 180 can be set arbitrarily, but in this embodiment, the auxiliary circulation control device 100 is connected to an auxiliary circulation system (V-V ECMO) 10, an artificial ventilator 140, and the liquid crystal touch panel 180.
Then, by operating the LCD touch panel 180, the amount of blood gas exchange in the artificial lung is changed, and the respiratory efficiency (blood gas exchange status index) based on the body weight at that time is calculated, and based on this respiratory efficiency based on the body weight, it is determined whether the blood gas exchange status is appropriate.

In addition, when changing the amount of gas exchange in the blood in the artificial lung 120, the auxiliary circulation control device 100 changes the amount of gas exchange in accordance with the recovery time required for the biological lung to become less dependent on the auxiliary circulation, thereby making it possible to easily detach the auxiliary circulation system 10 from the patient P.
In addition, the auxiliary circulation control device 100 determines the respiratory efficiency according to the body weight when the amount of gas exchange of blood in the artificial lung 120 is reduced, and continues or releases the control for changing the amount of gas exchange.
The auxiliary circulation control device 100 also calculates, for example, the auxiliary circulation rate (ECMO Rate) in the auxiliary circulation system (VV ECMO) 10, in other words, the contribution of the auxiliary circulation.

In addition, when reducing the dependency on assisted circulation, the amount of gas exchange in the artificial lung is changed (reduced) while checking the recovery of the vital lung function to the extent that the vital lung can handle the current assisted circulation rate (ECMO Rate), making it possible to wean the assisted circulation device.

As shown in FIG. 4, the auxiliary circulation control device 100 includes, for example, a first signal receiving unit 151 to a sixth signal receiving unit 156, a first calculation unit 160, a second calculation unit 170, a gas exchange amount control unit 176, a first memory unit 165, a second memory unit 175, and a third memory unit 179, and is configured to perform various calculations at set time intervals.
In this embodiment, the auxiliary circulation control device 100 is configured to calculate and output signals input from each sensor in real time.

As shown in FIG. 4, the auxiliary circulation control device 100 is electrically connected to the artificial lung inhalation gas sensor 125, the artificial lung exhalation gas sensor 126, the patient inhalation gas sensor 142, the patient exhalation gas sensor 144, the oxygen saturation sensor 117, and the pulse oximeter 148, for example, via the first signal receiving unit 151 to the sixth signal receiving unit 156. The device is configured to input appropriate signals from these sensors.

The first signal receiving unit 151 is connected to the artificial lung intake gas sensor 125 and receives an artificial lung intake carbon dioxide (CO ₂ ) concentration signal contained in the artificial lung intake gas sent from the artificial lung intake gas sensor 125 .

The second signal receiving unit 152 is connected to the artificial lung exhaled gas sensor 126 and is configured to receive an artificial lung exhaled carbon dioxide (CO ₂ ) concentration signal contained in the artificial lung exhaled gas sent from the artificial lung exhaled gas sensor 126 .

The third signal receiving unit 153 is connected to the ventilator intake gas sensor 142 and is configured to receive an intake carbon dioxide (CO ₂ ) concentration signal contained in the intake air sent from the ventilator 140 to the living lung (NL) sent from the ventilator intake gas sensor 142.

The fourth signal receiving unit 154 is connected to the artificial ventilator exhaled gas sensor 144 and is configured to receive an exhaled carbon dioxide (CO ₂ ) concentration signal contained in the exhaled gas discharged by the natural lung (NL) sent from the artificial ventilator exhaled gas sensor 144.

The fifth signal receiving unit 155 is connected to the oxygen saturation sensor 117 and receives a signal from the oxygen saturation sensor 117 indicating the oxygen saturation of the blood after it has been oxygenated by the artificial lung 120 (blood oxygenation status index).

The sixth signal receiving unit 156 is connected to the pulse oximeter 148 and receives a blood oxygen saturation (blood oxygenation status index) signal of the patient (living body, human body) P sent from the pulse oximeter 148.

The first signal receiving unit 151 to the sixth signal receiving unit 156 output the received signals to the first calculation unit 160.

The first calculation unit 160 is configured to calculate various parameters based on signals input from, for example, the auxiliary circulation system 10, the artificial ventilator 140, the pulse oximeter 148, etc. Details of the first calculation unit 160 will be described later.

The second calculation unit 170 is configured to calculate, for example, the auxiliary circulation ratio (ECMO rate), respiratory efficiency (blood gas exchange status index), etc., based on the signals input from the first calculation unit 160 and the liquid crystal touch panel 180, and to determine whether the blood gas exchange status is appropriate based on the respiratory efficiency (blood gas exchange status index). Details of the second calculation unit 170 will be described later.

Next, the first calculation unit 160 will be described in detail with reference to FIG.
The first calculation unit 160 is configured by a computer.
As shown in FIG. 4, the first calculation unit 160 is connected to the first signal receiving unit 151 to the sixth signal receiving unit 156, and receives signals from these signal receiving units.
The first calculation unit 160 is configured to receive gas flow rate signals (not shown) of the inhaled and exhaled air of the artificial lung 120 and the artificial ventilator 140, respectively, via cables not shown.
In this embodiment, the gas supply amounts of the artificial lung 120 and the artificial ventilator 140 are used as the inhalation and exhalation gas flow rates.
Moreover, the first calculation unit 160 is connected to, for example, a first storage unit 165 .

As shown in FIG. 4, the first calculation unit 160 includes, for example, an artificial lung carbon dioxide discharge amount calculation unit 161, an artificial ventilator carbon dioxide discharge amount calculation unit 162, an artificial lung oxygen saturation (blood oxygenation status index) calculation unit 163, and a biological oxygen saturation (blood oxygenation status index) calculation unit 164.

The first calculation unit 160 then refers to the first storage unit 165 as necessary and calculates various parameters based on the signals input via the first signal reception unit 151 to the sixth signal reception unit 156. The first calculation unit 160 then outputs the calculation results to the second calculation unit 170.

The first storage unit 165 is configured with, for example, a hard disk.
In addition, the first memory unit 165 stores, for example, constants, data tables, formulas for calculation, etc. that are referred to when the artificial lung carbon dioxide emission amount calculation unit 161, the artificial ventilator carbon dioxide emission amount calculation unit 162, the artificial lung oxygen saturation calculation unit 163, and the biological oxygen saturation calculation unit 164 perform calculations.

As shown in FIG. 4 , the oxygenator carbon dioxide emission amount calculation unit 161 receives an oxygenator inhalation carbon dioxide (CO ₂ ) concentration signal and an oxygenator exhalation carbon dioxide (CO ₂ ) concentration signal via a first signal receiving unit 151 and a second signal receiving unit 152 .
In addition, the oxygenator carbon dioxide emission amount calculation unit 161 receives a signal (not shown) of the gas supply amount (inhalation and exhalation gas flow rate) of the oxygenator 120 .

The oxygenator carbon dioxide emission calculation unit 161 then calculates the amount of carbon dioxide (CO ₂ ) emitted from the oxygenator 120 (V′CO ₂ (ML)) based on the received carbon dioxide (CO ₂ ) concentration signals contained in the inhaled and exhaled air and the amount of gas supplied to the oxygenator 120 .

Specifically, the carbon dioxide (CO ₂ ) concentration difference in the artificial lung 120 is calculated from the carbon dioxide (CO ₂ ) concentration contained in the inhaled air of the artificial lung 120 and the carbon dioxide (CO ₂ ) concentration contained in the exhaled air, and the product of the carbon dioxide (CO ₂ ) concentration difference generated in the artificial lung 120 and the gas supply amount of the artificial lung 120 is calculated to calculate the amount of carbon dioxide discharged from the artificial lung 120 (V'CO ₂ (ML)).

Below, an outline of the calculation procedure in the artificial lung carbon dioxide discharge calculation unit 161 will be described with reference to FIG. 5. FIG. 5 is a flowchart showing an outline of the calculation procedure in the artificial lung carbon dioxide discharge calculation unit 161.

(1) First, the artificial lung inhaled carbon dioxide concentration data is received via the first reception unit 151 (S101).
(2) Next, the artificial lung exhaled carbon dioxide concentration data is received via the second reception unit 152 (S102).

(3) Next, the difference in the carbon dioxide concentration in the oxygen saturation gas is calculated based on the data of the carbon dioxide concentration in the oxygen saturation gas and the data of the carbon dioxide concentration in the oxygen saturation gas (S103).
The difference in carbon dioxide concentration in the artificial lung is calculated, for example, by the following formula.
Artificial lung carbon dioxide concentration difference = Artificial lung exhaled carbon dioxide concentration - Artificial lung inhaled carbon dioxide concentration

(4) Data on the amount of artificial lung gas supplied to the artificial lung main body 121 is received from the artificial lung gas supply device 122 (S104).
(5) Then, the amount of carbon dioxide discharged from the oxygenator is calculated (S105).
The amount of carbon dioxide discharged from the artificial lung can be calculated, for example, by the following formula.
Artificial lung carbon dioxide emissions (V'CO ₂ (ML)
= Carbon dioxide concentration difference in artificial lung 120 × gas supply amount of artificial lung 120 = (carbon dioxide concentration in artificial lung exhaled air - carbon dioxide concentration in artificial lung inhaled air) × gas supply amount of artificial lung 120 When executing the above steps (S101) to (S105), a data table (not shown) stored in the first memory unit 165 is referenced as necessary.

Then, the oxygen suction amount calculation unit 161 outputs the oxygen suction amount _CO2 concentration signal, the oxygen suction amount CO2 concentration signal, the oxygen suction amount _CO2 concentration signal, the oxygen suction amount gas supply amount signal, and the calculated amount of carbon dioxide discharged from the oxygen suction amount ( _V'CO2 (ML)) to the auxiliary circulation ratio (auxiliary circulation contribution) calculation unit 171.

As shown in FIG. 4 , the ventilator carbon dioxide emission amount calculation unit 162 receives the ventilator intake carbon dioxide (CO ₂ ) concentration signal and the ventilator carbon dioxide (CO ₂ ) concentration signal via the third signal receiving unit 153 and the fourth signal receiving unit 154 .
In addition, the ventilator carbon dioxide emission calculation unit 162 receives a gas supply volume (inhalation and exhalation gas flow rate) signal (not shown) from the ventilator 140 .

The artificial ventilator carbon dioxide emission amount calculation unit 162 then calculates the amount of carbon dioxide (CO ₂ ) emitted (V'CO ₂ (NL)) in the living lungs (NL) based on the received carbon dioxide (CO ₂ ) concentration signals contained in the inhaled and exhaled air.

Specifically, the carbon dioxide (CO ₂ ) concentration difference in the artificial ventilator 140 is calculated from the carbon dioxide (CO ₂ ) concentration contained in the inhaled air of the artificial ventilator 140 and the carbon dioxide (CO ₂ ) concentration contained in the exhaled air, and the product of the carbon dioxide (CO ₂ ) concentration difference generated in the artificial ventilator 140 and the gas supply amount of the artificial ventilator 140 is calculated to calculate the carbon dioxide emission amount (V'CO ₂ (NL)) in the artificial ventilator 140. Note that the carbon dioxide emission amount in the artificial ventilator 140 is the carbon dioxide emission amount of the living lung (NL).

Below, an outline of the calculation procedure in the ventilator carbon dioxide emission calculation unit 162 will be described with reference to FIG. 6. FIG. 6 is a flowchart showing an outline of the calculation procedure in the ventilator carbon dioxide emission calculation unit 162.

(1) First, the artificial ventilator intake carbon dioxide concentration data is received via the third reception unit 153 (S201).
(2) Next, the artificial ventilator exhaled carbon dioxide concentration data is received via the third reception unit 154 (S202).
(3) Next, the ventilator carbon dioxide concentration difference (= ventilator exhaled carbon dioxide concentration - ventilator inhaled carbon dioxide concentration) is calculated based on the ventilator inhaled carbon dioxide concentration data and the ventilator exhaled carbon dioxide concentration data (S203).
(4) Receive ventilator gas supply data from the ventilator 140 (S204).

(5) Then, the amount of carbon dioxide discharged from the artificial respirator is calculated (S205).
The ventilator carbon dioxide output can be calculated, for example, by the following formula:
Ventilator carbon dioxide output ( _V'CO2 (NL))
= Carbon dioxide concentration difference in ventilator 140 × Gas supply amount of ventilator 140 = (ventilator exhaled carbon dioxide concentration - ventilator inhaled carbon dioxide concentration) × Gas supply amount of ventilator 140 When executing the above steps (S201) to (S205), a data table (not shown) stored in the first memory unit 165 is referenced as necessary.
In this embodiment, the amount of carbon dioxide discharged from the living lungs (NL) (V'CO ₂ (NL)) is calculated by volumetric capnoanalysis or the like.

Then, the ventilator carbon dioxide emission amount calculation unit 162 outputs the ventilator inhalation carbon dioxide (CO ₂ ) concentration signal, the ventilator exhalation carbon dioxide (CO ₂ ) concentration signal, the ventilator gas supply volume signal, and the calculated carbon dioxide emission amount in the living lung (NL) (V'CO ₂ (NL)) to the auxiliary circulation ratio (auxiliary circulation contribution) calculation unit 171.

As shown in FIG. 4, the oxygen saturation (blood oxygenation status index) calculation unit 163 receives an oxygen saturation (blood oxygenation status index) signal of blood oxygenated in the artificial lung 120 from the oxygen saturation sensor 117 via the fifth signal receiving unit 155.

Then, the artificial lung oxygen saturation calculation unit 163, for example, refers to a data table (not shown) stored in the first memory unit 165 as necessary to calculate the artificial lung oxygen saturation (an index of the blood oxygenation status of the artificial lung) contained in the exhaled air of the artificial lung 120, and outputs it to the oxygen saturation display unit 174.

As shown in FIG. 4, the living organism oxygen saturation (blood oxygenation status index) calculation unit 164 receives a blood oxygen saturation (blood oxygenation status index) signal in the patient (living organism) P from the pulse oximeter 148 via the sixth signal receiving unit 156.

Then, the living organism oxygen saturation calculation unit 164, for example, refers to a data table (not shown) stored in the first memory unit 165 as necessary to calculate the oxygen saturation (blood oxygenation status index) of the patient (living organism) P, and outputs it to the oxygen saturation (blood oxygenation status index) display unit 174.

Next, the second calculation unit 170 will be described in detail with reference to FIG.
The second calculation unit 170 is configured by a computer.
As shown in FIG. 4, the second calculation unit 170 is connected to the first calculation unit 160 and receives the calculation results from the first calculation unit 160 .

The second calculation unit 170 also includes, for example, an auxiliary circulation ratio (auxiliary circulation contribution) calculation unit 171, a blood gas exchange status index calculation unit 172, a gas exchange status determination unit (blood gas exchange status determination unit) 173, and an oxygen saturation (blood oxygenation status index) display unit 174. The second calculation unit 170 is also connected to a second memory unit 175.

The second storage unit 175 is configured by, for example, a hard disk.
The second memory unit 175 stores, for example, formulas and constants for calculations in the second calculation unit 170, gas exchange status determination thresholds for the gas exchange status determination unit (blood gas exchange status determination unit) 173 to determine the blood gas exchange status, or data tables constituting gas exchange status determination threshold patterns corresponding to blood gas exchange status indicators.

The auxiliary circulation ratio (auxiliary circulation contribution) calculation unit 171 calculates the total carbon dioxide (CO ₂ ) emission amount in the entire living body and the auxiliary circulation ratio (ECMO Rate) (auxiliary circulation contribution) in the auxiliary circulation (V-V ECMO) based on signals sent from the artificial lung carbon dioxide emission amount calculation unit 161 and the artificial ventilator carbon dioxide emission amount calculation unit 162.

Specifically, the auxiliary circulation ratio (auxiliary circulation contribution) calculation unit 171 calculates the total carbon dioxide (CO ₂ ) emission from the entire living body from the artificial lung carbon dioxide (CO ₂ ) emission amount and the artificial ventilator carbon dioxide (CO ₂ ) emission amount, and then calculates the auxiliary circulation ratio (ECMO Rate).

Below, an outline of the calculation procedure in the auxiliary circulation ratio calculation unit 171 will be described with reference to FIG. 7. FIG. 7 is a flowchart showing an outline of the calculation procedure in the auxiliary circulation ratio calculation unit 171.

(1) First, the amount of carbon dioxide (CO ₂ ) discharged from the artificial lung is obtained (S301).
(2) Next, the amount of carbon dioxide (CO ₂ ) discharged from the artificial respirator is obtained (S302).

(3) Next, the total carbon dioxide (CO ₂ ) discharge amount is calculated based on the artificial lung carbon dioxide (CO ₂ ) discharge amount and the artificial respirator carbon dioxide (CO ₂ ) discharge amount (S303).
The total carbon dioxide (CO ₂ ) emission amount is calculated, for example, by the following formula.
Total carbon dioxide output ( _V'CO2 ) = artificial lung carbon dioxide output ( _V'CO2 (ML)) + artificial ventilator carbon dioxide output ( _V'CO2 (NL))

(4) Then, the ECMO rate (contribution of the auxiliary circulation) is calculated (S304).
The auxiliary circulation rate (ECMO Rate) is calculated, for example, by the following formula.
ECMO Rate = Carbon dioxide output from artificial lung (V'CO ₂ (ML)) / Total carbon dioxide output from whole body (V'CO ₂ )

The auxiliary circulation ratio calculation unit 171 then continuously outputs in real time to the liquid crystal touch panel (display unit) 180, for example, the artificial lung inhaled carbon dioxide concentration, the artificial lung exhaled carbon dioxide concentration, the artificial lung gas supply amount, the artificial lung carbon dioxide discharge amount, the artificial ventilator inhaled carbon dioxide concentration, the artificial ventilator exhaled carbon dioxide concentration, the artificial ventilator gas supply amount, the artificial ventilator carbon dioxide discharge amount, and the auxiliary circulation ratio (ECMO Rate).

Furthermore, the auxiliary circulation ratio calculation section 171 outputs, for example, the total carbon dioxide emission amount and the carbon dioxide (CO ₂ ) emission amount in the artificial ventilator 140 to the blood gas exchange status index calculation section 172 .

The auxiliary circulation ratio calculation unit 171 may be configured to acquire parameters related to oxygen (O ₂ ) instead of carbon dioxide (CO ₂ ) and continuously output in real time to the liquid crystal touch panel (display unit) 180, for example, the artificial lung inhaled oxygen concentration, the artificial lung exhaled oxygen concentration, the artificial lung gas supply amount, the artificial lung oxygen intake amount, the artificial ventilator inhaled oxygen concentration, the artificial ventilator exhaled oxygen concentration, the artificial ventilator gas flow rate, the living lung oxygen intake amount, the auxiliary circulation ratio (ECMO Rate), and the breathing efficiency based on the weight of the patient P.

The blood gas exchange status index calculation unit 172 calculates the respiratory efficiency (blood gas exchange status index) based on the weight of the patient (living body) P based on the total carbon dioxide (CO ₂ ) emission amount sent from the auxiliary circulation ratio calculation unit 171 and the weight of the patient (living body) P inputted using a numeric keypad (not shown) provided on the LCD touch panel 180.

Specifically, the blood gas exchange status index calculation unit 172 calculates the respiratory efficiency based on body weight from the total amount of carbon dioxide (CO ₂ ) emitted and the amount of carbon dioxide due to the estimated metabolism of the patient P calculated based on the body weight of the patient (living body) P.

For example, the auxiliary circulation ratio calculation unit 171 may calculate the amount of carbon dioxide ( _CO2 ) discharged in the ventilator 140, and the blood gas exchange status index calculation unit 172 may calculate the respiratory efficiency based on body weight based on the total amount of carbon dioxide ( _CO2 ) discharged by the patient (entire living organism) P and the amount of carbon dioxide ( _CO2 ) discharged due to metabolism (at rest) estimated from the patient P's body weight, and may calculate the spontaneity rate based on the amount of carbon dioxide ( _CO2 ) discharged by the patient P's living lungs (NL) and the total amount of carbon dioxide ( _CO2 ) discharged.
The spontaneity rate focusing on carbon dioxide (CO ₂ ) emission can be expressed by the following formula.
Spontaneity rate = carbon dioxide (CO ₂ ) discharged by living lung (NL) V'CO2 (NL) / (carbon dioxide (CO ₂ ) discharged by artificial lung (ML) V'CO2 (ML) + carbon dioxide (CO ₂ ) discharged by living lung (NL) V'CO2 (NL))
The spontaneous circulation rate focusing on the amount of carbon dioxide (CO ₂ ) discharge can be calculated uniquely from the extracorporeal circulation rate (ECMO Rate).

Below, an outline of the calculation procedure in the blood gas exchange status index calculation unit 172 will be described with reference to FIG. 8. FIG. 8 is a flowchart showing an outline of the calculation procedure in the blood gas exchange status index calculation unit 172.

(1) First, the weight data of patient P is received (S401).
The weight data of the patient P is input, for example, by a numeric keypad (not shown) provided on the liquid crystal touch panel 180 .

(2) Next, the amount of carbon dioxide (CO ₂ ) due to metabolism (at rest) estimated from the weight of the patient P (hereinafter, sometimes referred to as the amount of carbon dioxide due to the patient's estimated metabolism) is calculated (S402).
The amount of carbon dioxide (CO ₂ ) due to the estimated metabolism of the patient P can be approximated by calculation using, for example, the following formula.
Estimated metabolic carbon dioxide ( _CO2 ) amount of patient P = [1 MET] x 0.8 x body weight of patient P Here, MET (metabolic equivalent) indicates an evaluation of exercise intensity, and 1 MET is represented by the amount of oxygen intake at rest (3.5 ml/kg/min).
0.8: Respiratory quotient constant (respiratory quotient)

(3) Next, the total carbon dioxide (CO ₂ ) emission amount sent from the auxiliary circulation ratio calculation unit 171 is acquired (S403).

(4) Then, the respiratory efficiency based on the weight of the patient P is calculated (S404).
The respiratory efficiency based on the weight of the patient P can be calculated, for example, by the following formula.
Respiratory efficiency by body weight = total carbon dioxide output / estimated metabolic carbon dioxide (CO ₂ ) amount of patient P

Then, the blood gas exchange status index calculation unit 172 continuously outputs the respiratory efficiency based on the weight of the patient P to the liquid crystal touch panel (display unit) 180, for example.
In addition, the blood gas exchange status index calculation unit 172 outputs the respiratory efficiency based on the weight of the patient P to the gas exchange status determination unit 173.

The gas exchange status determination unit 173 determines whether the blood gas exchange status is appropriate based on the respiratory efficiency (blood gas exchange status index) according to body weight sent from the blood gas exchange status index calculation unit 172.

Specifically, the gas exchange status determination unit 173 compares the respiratory efficiency (blood gas exchange status index) with a preset gas exchange status determination threshold value to determine whether the auxiliary circulation is functioning properly.
The gas exchange status determination unit 173 then continuously outputs in real time to the gas exchange volume control unit 176 and the LCD touch panel 180 the respiratory efficiency based on the patient P's weight, the total carbon dioxide excretion amount, and signals regarding the determined results received from the blood gas exchange status index calculation unit 172.

Below, an outline of the calculation procedure in the gas exchange status determination unit (blood gas exchange status determination unit) 173 will be described with reference to FIG. 9. FIG. 9 is a flowchart showing an outline of the determination procedure in the gas exchange status determination unit 173.

(1) First, the gas exchange status determination unit 173 acquires a gas exchange status determination threshold value (S501).
The gas exchange status determination threshold may be obtained, for example, by referring to the second storage unit 175 and acquiring a threshold pattern set in correspondence with numerical data or changes in respiratory efficiency due to body weight as a data table.

(2) Next, the gas exchange status determination unit 173 compares the respiratory efficiency based on the weight of the patient P with a gas exchange status determination threshold to determine whether the blood gas exchange status is appropriate (S502).
Specifically, for example, if the respiratory efficiency based on the weight of the patient P is equal to or greater than the gas exchange status determination threshold (S502: Yes), the process proceeds to S502.
At this time, the change in the gas exchange amount by the gas exchange amount control unit 176 continues.
On the other hand, if the respiratory efficiency based on the weight of the patient P is not greater than or equal to the gas exchange status determination threshold (S502: No), the process proceeds to S503.

(3) The gas exchange status determination unit (blood gas exchange status determination unit) 173 outputs a signal indicating that the blood gas exchange status is inappropriate to the gas exchange amount control unit 176 and the liquid crystal touch panel 180. (S503)
(4) When a signal indicating an inappropriate blood gas exchange status is output from the gas exchange status determination unit (blood gas exchange status determination unit) 173, the control by the gas exchange amount control unit 176 to change the amount of blood gas exchange in the artificial lung 120 is stopped (e.g., released), and, for example, the amount of artificial lung intake gas supplied to the artificial lung 120 and the blood flow rate are restored to the state before the gas exchange amount fluctuation control was started.
The gas exchange status determining unit (blood gas exchange status determining unit) 173 executes S501 to S503 until an end instruction is received from the liquid crystal touch panel (display unit) 180, for example.

As shown in FIG. 4 , the oxygen saturation display unit 174 receives, for example, the oxygen saturation from the oxygen saturation calculator 163 and the oxygen saturation of the patient (living body) P from the living body oxygen saturation calculator 164 .
The oxygen saturation display unit 174 outputs and displays, for example, the oxygen saturation of the artificial lung and the oxygen saturation of the patient (living body) P on the liquid crystal touch panel 180 .
The oxygen saturation display unit 174 may also compare the oxygen saturation of the oxygen lung and the oxygen saturation of the patient (living body) P with respective thresholds. The oxygen saturation display unit 174 may also be configured to output an alarm when an abnormality is detected, such as the oxygen saturation of the oxygen lung falling below a set threshold.
The threshold value is inputted, for example, by a numeric keypad (not shown) provided on the liquid crystal touch panel 180 and is stored in a storage unit (not shown).

The oxygen saturation display unit 174 then outputs signals related to, for example, the artificial lung oxygen saturation, the biological oxygen saturation, and an alarm to the liquid crystal touch panel (display unit) 180 in real time.

The gas exchange amount control unit 176 is configured, for example, by a computer.
As shown in FIG. 4, the gas exchange amount control unit 176 includes, for example, an artificial lung inhalation gas supply amount calculation unit 177, an artificial lung inhalation gas control unit 178A, and a blood pump flow rate control unit 178B.

Furthermore, the gas exchange amount control unit 176 is electrically connected to, for example, the liquid crystal touch panel 180 , the artificial lung gas supply device 122 , the centrifugal pump (blood supply pump) 115 , and a third memory unit 179 .
Specifically, the artificial lung intake gas control unit 178A is connected to the artificial lung gas supply device 122, and the blood supply pump flow rate control unit 178B is connected to the centrifugal pump (blood supply pump) 115 via a centrifugal pump driver 115D.

The third storage unit 179 is configured by, for example, a hard disk.
The third storage unit 179 also stores a data table constituting a gas exchange amount control pattern in the artificial lung 120, for example, in the steady-state control of the gas exchange amount and the fluctuating control of the gas exchange amount. Specifically, the oxygen content of the artificial lung inhalation gas supplied to the artificial lung 120 and the blood flow rate sent to the artificial lung 120 are stored in association with the elapsed time since the start of the change in the gas exchange amount.

When a signal to start steady-state operation or gas exchange volume control by increasing or decreasing the gas exchange volume is input from the LCD touch panel 180 by operating the LCD touch panel 180, the gas exchange volume control unit 176 refers to the third memory unit 179 and outputs a signal to control the supply volume of artificial lung intake gas supplied by the artificial lung gas supply device 122 to the artificial lung main body 121.
Specifically, during steady-state operation, the oxygen content of the artificial lung inhalation gas is controlled within a predetermined range, and during variable operation, the oxygen content of the artificial lung inhalation gas is changed (increased or decreased) according to a set control pattern.

In addition, when the gas exchange volume control unit 176 changes the oxygen ( _O2 ) content contained in the artificial lung intake gas supply volume supplied to the artificial lung 120, it refers to the third memory unit 179, for example, to calculate the oxygen ( _O2 ) concentration of the artificial lung intake gas and the artificial lung intake gas supply volume, and outputs them to the artificial lung intake gas control unit 178A.

In addition, the gas exchange volume control unit 176, for example, refers to the third memory unit 179 to calculate the blood flow rate sent by the centrifugal pump (blood supply pump) 115 to the artificial lung 120 in correspondence with the oxygen ( _O2 ) content of the artificial lung inhalation gas, and outputs it to the blood supply pump flow rate control unit 178B.
The blood pump flow rate control unit 178B outputs a control signal to the centrifugal pump 115 via the centrifugal pump driver 115D.
As a result, the blood flow rate sent from the centrifugal pump 115 to the oxygenator 120 changes in response to the oxygenator inhalation gas supply rate.

Below, an outline of the procedure for steady-state gas exchange control in the gas exchange amount control unit 176 will be described with reference to FIG. 10. FIG. 10 is a flowchart showing an outline of the procedure for steady-state gas exchange control by the gas exchange amount control unit.

The gas exchange rate steady-state control is started, for example, by receiving a gas exchange rate steady-state control signal output by operating the liquid crystal touch panel 180 .
The gas exchange volume control unit 176 receives the gas exchange volume steady-state control signal, and for example, in the artificial lung intake gas supply volume calculation unit 177, calculates the artificial lung intake gas supply volume and blood supply flow rate so that pre-set trigger items (e.g., oxygen saturation after artificial lung (blood oxygenation status index), respiratory efficiency based on the weight of patient P (blood gas exchange status index), oxygen intake in the artificial lung, etc.) are within predetermined ranges, and outputs them to the artificial lung intake gas control unit 178A and the blood supply pump flow rate control unit 178B. Specifically, if the amount of carbon dioxide ( _CO2 ) due to the estimated metabolism of patient P is set as a constant, the total carbon dioxide emission volume is controlled to be within a predetermined range.

(1) First, the oxygenator inhalation gas supply amount calculation unit 177 receives a gas exchange amount steady control signal output by operating the liquid crystal touch panel 180 (S601).
(2) Next, the oxygen supply amount calculator 177 refers to the third memory 179 and calculates the oxygen supply amount and the blood flow rate based on the data obtained by the second calculator 170 (S602).

(3) Next, the artificial lung intake gas supply amount calculation unit 177 outputs a control signal of the calculated artificial lung intake gas supply amount to the artificial lung gas supply device 122 via the artificial lung intake gas control unit 178A. (S603)

(4) Next, the artificial lung intake gas supply calculation unit 177 outputs the result to the centrifugal pump 115 via the blood pump flow control unit 178B and the centrifugal pump driver 115D. (S604)

(5) Next, the artificial lung intake gas supply amount calculation unit 177 checks whether the gas exchange status determination unit (blood gas exchange status determination unit) 173 has output a signal indicating that the blood gas exchange status of the patient P is inappropriate (S605).
If the gas exchange status determination unit 173 outputs a signal indicating that the blood gas exchange status of the patient P is inappropriate (S605: No), the process proceeds to S602. In S602, the artificial lung inhalation gas supply amount calculation unit 177 refers to the third storage unit 179 and calculates the corresponding artificial lung inhalation gas supply amount and blood feed flow rate based on the respiratory efficiency according to the weight of the patient P calculated by the gas exchange status determination unit 173.
On the other hand, if the gas exchange status determination unit 173 has not output a signal indicating that the blood gas exchange status of the patient P is inappropriate (S605: Yes), the process proceeds to S603.
At this time, the oxygenator inhalation gas supply amount calculation unit 177 continues to output the oxygenator inhalation gas supply amount and the blood supply flow rate to the oxygenator to the nest without changing them.
S601 to S605 are performed, for example, until the steady-state gas exchange rate control is completed.

Next, gas exchange rate fluctuation control will be described with reference to FIG.
The gas exchange rate variation control is, for example, started by receiving a gas exchange rate variation control signal output by operating the liquid crystal touch panel 180, and is a control for varying (changing) the blood gas exchange rate based on a preset program (control pattern, formula, etc.) Specifically, it includes at least either one of decreasing the gas exchange rate in the artificial lung or increasing the gas exchange rate.

In the case of reducing the amount of gas exchange of blood in the artificial lung 120, for example, this is applied to whether or not to reduce the auxiliary circulation rate (ECMO Rate) or to disconnect the auxiliary circulation system by reducing the auxiliary circulation rate (ECMO Rate) to zero.
In addition, when the amount of gas exchange by the artificial lung is increased, for example, the present invention is applied to confirm the necessity of increasing the auxiliary circulation rate (ECMO Rate).

(1) First, as shown in FIG. 11, the artificial lung intake gas supply calculation unit 177 receives a gas exchange rate fluctuation control signal output by operating the liquid crystal touch panel 180. (S701)

(2) Next, the artificial lung inhalation gas supply amount calculation unit 177 acquires a gas exchange amount variation control pattern based on the data obtained by the second calculation unit 170, with reference to the program stored in the third storage unit 179. Specifically, it acquires the artificial lung inhalation gas supply amount supplied by the artificial lung gas supply device 122 to the artificial lung main body 121, and the blood sending flow rate corresponding to the amount of oxygen ( _O2 ) contained in the artificial lung inhalation gas output to the centrifugal pump 115 via the centrifugal pump driver 115D. (S702)

The gas exchange rate variation control pattern is configured, for example, to reduce the amount of blood gas exchange in the artificial lung 120 in correspondence with the recovery time during which the vital lung (NL) becomes less dependent on the auxiliary circulation when changing the amount of blood gas exchange in the artificial lung 120. This is advantageous because it allows the degree of dependency on the auxiliary circulation to be changed while checking the recovery of the vital lung (NL) function, allowing the auxiliary circulation device to be smoothly removed.

(3) Next, the artificial lung intake gas supply amount calculation unit 177 outputs a control signal to the artificial lung gas supply device 122 to change the artificial lung intake gas supply amount based on the acquired gas exchange amount control pattern. (S703)

(4) In addition, the artificial lung intake gas supply calculation unit 177 outputs a control signal to the centrifugal pump driver 115D to change the blood flow rate of the centrifugal pump 115 based on the gas exchange control pattern. (S704)

(5) Next, the artificial lung intake gas supply amount calculation unit 177 checks whether or not there is a gas exchange amount fluctuation control end signal (S705).
The gas exchange volume fluctuation control end signal is output, for example, upon elapsed time, a set blood gas exchange volume, achievement of a target blood gas exchange status index, or end of the gas exchange volume control pattern.
If there is no gas exchange amount fluctuation control end signal (S705: No), the process proceeds to S706.
On the other hand, if there is a gas exchange amount fluctuation control end signal (S705: Yes), the process proceeds to S708.

(6) Next, the artificial lung intake gas supply amount calculation unit 177 checks whether the gas exchange status determination unit (blood gas exchange status determination unit) 173 has output a signal indicating that the blood gas exchange status of the patient P is inappropriate (S706).
If the blood gas exchange status index is not inappropriate (S706: No), the process proceeds to S703.
On the other hand, if the blood gas exchange status index is inappropriate (S706: Yes), the process proceeds to S707.

(7) The oxygen supply amount calculator 177 controls the oxygen supply amount and blood flow rate to the oxygenator 120 to the values before the gas exchange rate fluctuation control is started (S707).
The artificial lung intake gas supply amount and blood feed flow rate set at the end of the gas exchange amount fluctuation control may be returned to the state when the gas exchange amount fluctuation control was started, or may remain as a preset value, or the artificial lung intake gas supply amount and blood feed flow rate when the blood gas exchange state was confirmed to be inappropriate in S606, or may be changed to an artificial lung intake gas supply amount and blood feed flow rate corrected by a certain value or ratio. Also, the artificial lung intake gas supply amount and blood feed flow rate stored in the third memory unit 179 may be changed.
In addition, the gas exchange rate fluctuation control may be resumed after the artificial lung intake gas supply rate and blood supply rate have been changed to predetermined values.

(8) The oxygen supply amount calculation unit 177 stops executing the gas exchange amount fluctuation control based on the program (S708).
Note that stopping the gas exchange rate variation control may mean either canceling the gas exchange rate variation control or temporarily suspending it, and is executed regardless of an instruction from liquid crystal touch panel 180. Furthermore, in S705, when the gas exchange rate variation control detects an end signal, this means that the gas exchange rate variation control has ended.
S703 to S706 are performed, for example, until the artificial lung 120 is removed, the control for changing the gas exchange rate is stopped (eg, released), or the gas exchange rate variation control is ended.

Next, the schematic configuration of the liquid crystal touch panel 180 will be described with reference to FIG.
As shown in FIG. 12 , the liquid crystal touch panel 180 includes, for example, an artificial lung respiration display section 181, an artificial ventilator respiration display section 182, a living body's carbon dioxide emission amount display section 183, a living body's estimated metabolic carbon dioxide amount display section 184, an auxiliary circulation ratio (ECMO Rate) (blood gas exchange status index) display section 185, a body weight-based respiration efficiency (blood gas exchange status index) display section 186, a living body's oxygen saturation display section 187, a graph display section 188, and a panel switch section (operation section) 189.

As shown in FIG. 12, the artificial lung respiration display unit 181 includes, for example, an artificial lung inhalation carbon dioxide (CO ₂ ) concentration display unit 181A, an artificial lung exhalation carbon dioxide (CO ₂ ) concentration display unit 181B, an artificial lung gas supply amount display unit 181C, and an artificial lung carbon dioxide (CO ₂ ) discharge amount display unit 181D.

In this embodiment, the artificial lung inhaled carbon dioxide (CO ₂ ) concentration display unit 181A, the artificial lung exhaled carbon dioxide (CO ₂ ) concentration display unit 181B, the artificial lung gas supply volume display unit 181C, and the artificial lung carbon dioxide (CO ₂ ) discharge volume display unit 181D display the artificial lung inhaled carbon dioxide (CO ₂ ) concentration, the artificial lung exhaled carbon dioxide (CO ₂ ) concentration, the artificial lung gas supply volume, and the artificial lung carbon dioxide (CO ₂ ) discharge volume output by the auxiliary circulation ratio calculation unit 171.

As shown in FIG. 12, the ventilator respiration display unit 182 includes, for example, a ventilator inhalation carbon dioxide ( _CO2 ) concentration (ventilator inhalation gas concentration) display unit 182A, a ventilator exhalation carbon dioxide ( _CO2 ) concentration display unit 182B, a ventilator gas supply volume display unit 182C, and a living lung carbon dioxide emission volume display unit 182D.

In this embodiment, the ventilator inhalation carbon dioxide (CO ₂ ) concentration display unit 182A, the ventilator exhalation carbon dioxide (CO ₂ ) concentration display unit 182B, the ventilator gas supply volume display unit 182C, and the vital lung carbon dioxide (CO ₂ ) emission volume display unit 182D display the ventilator inhalation carbon dioxide (CO ₂ ) concentration, the ventilator exhalation carbon dioxide (CO ₂ ) concentration, the ventilator gas supply volume, and the carbon dioxide (CO ₂ ) emission volume in the vital lung (NL) output by the auxiliary circulation ratio calculation unit 171.

The living body carbon dioxide emission display unit 183 displays, for example, the total carbon dioxide emission of the patient P output by the auxiliary circulation ratio calculation unit 171.

The carbon dioxide amount due to estimated metabolism of the living body display section 184 displays, for example, the amount of carbon dioxide (CO ₂ ) due to the estimated metabolism of the patient P outputted by the auxiliary circulation ratio calculation section 171 .

The auxiliary circulation rate (ECMO rate) display unit 185 displays, for example, the auxiliary circulation rate (ECMO rate) (blood gas exchange status index) output by the auxiliary circulation rate index calculation unit 171 as a numerical value (%).

The respiratory efficiency by weight display unit 186 displays, for example, the respiratory efficiency (blood gas exchange status index) by the patient P's weight output by the blood gas exchange status index calculation unit 172 as a numerical value (%).

The oxygen saturation display unit 187 includes, for example, a post-artificial lung oxygen saturation display unit 187A that displays the oxygen saturation after gas exchange in the artificial lung 120, and a living body oxygen saturation display unit 187B that displays the oxygen saturation of the patient P.
A post-oxygenation lung oxygen saturation display unit 187A and a living body oxygen saturation display unit 187B receive the oxygen saturation signals of the oxygenator 120 and the living body output by the oxygen saturation display unit 174, and display them as numerical values.

As shown in FIG. 12, the graph display section 188 includes, for example, an auxiliary circulation rate (ECMO Rate) display section 188A, a respiratory efficiency based on body weight display section 188B, and a living lung/artificial lung oxygen saturation display section 188C.
The auxiliary circulation rate (ECMO Rate) display unit 188A displays, for example, a graph A of the auxiliary circulation rate (ECMO Rate) output by the auxiliary circulation rate calculation unit 171 in real time and in time series.

The respiratory efficiency display unit 188B based on body weight and body weight displays, for example, a graph B of the respiratory efficiency (blood gas exchange status index) based on body weight output by the blood gas exchange status index calculation unit 172 in real time and in chronological order.

The living body/artificial lung oxygen saturation display unit 188C also displays, for example, a graph C1 of the oxygen saturation after the artificial lung 120 output by the oxygen saturation display unit 174, and a graph C2 of the oxygen saturation of the patient (living body) P in real time and in chronological order.

As shown in FIG. 12, the panel switch section (operation section) 189 includes, for example, a first touch section 189A, a second touch section 189B, a third touch section 189C, and a fourth touch section 189D.

The first touch section 189A, for example, allows the selection of whether to use oxygen (O ₂ ) intake, carbon dioxide (CO ₂ ) output, or oxygen (O ₂ ) intake and carbon dioxide (CO ₂ ) output as a gas exchange parameter when the auxiliary circulation control device 100 monitors the auxiliary circulation (V-V ECMO) by selecting a GUI (Graphical User Interface).

The second touch section 189B allows the user to select, by touch operation, whether to display the contribution of auxiliary circulation (V-V ECMO) as the auxiliary circulation ratio (ECMO Rate) or as the ratio of the artificial lung gas exchange volume to the artificial ventilator gas exchange volume (artificial lung gas exchange volume: artificial ventilator gas exchange volume).

The third touch unit 189C can, for example, select whether the auxiliary circulation control device 100 will perform steady-state gas exchange volume control or fluctuating gas exchange volume control.

The fourth touch unit 189D can output a signal to start the gas exchange volume control unit 176 controlling (increasing or decreasing) the fluctuations in the gas exchange volume of blood in the artificial lung 120 or to stop controlling the fluctuations in the gas exchange volume, for example, depending on the number of touches.

The auxiliary circulation control device 100 according to the first embodiment is equipped with a blood gas exchange status index calculation unit 172, a gas exchange amount control unit 176 that changes the amount of blood gas exchange in the artificial lung 120 having an artificial lung intake gas control unit 178A and a blood supply pump control unit 178B, so that the amount of blood gas exchange by the auxiliary circulation device can be changed while checking the respiratory efficiency according to body weight.

In addition, according to the auxiliary circulation control device 100, when the gas exchange amount control unit 176 changes the gas exchange amount of blood in the artificial lung 120, it changes the oxygen content of the artificial lung intake gas supplied to the artificial lung 120 and the flow rate of blood sent to the artificial lung 120, so that the oxygen intake amount of blood in the artificial lung 120 can be easily and stably changed.

In addition, according to the auxiliary circulation control device 100, in steady-state gas exchange volume control, the gas exchange status determination unit 173 determines whether the respiratory efficiency (blood gas exchange status index) based on body weight is inappropriate, while the gas exchange volume control unit 176 adjusts the gas exchange volume in the artificial lung 120, so auxiliary circulation can be performed stably and safely.

Furthermore, according to the auxiliary circulation control device 100, the gas exchange status determination unit (blood gas exchange status determination unit) 173 determines whether the respiratory efficiency (blood gas exchange status index) based on body weight is inappropriate when the amount of blood gas exchange by the artificial lung 120 is varied, so that it is possible to efficiently determine, for example, whether it is possible to reduce the degree of dependence on auxiliary circulation.
As a result, it is possible to efficiently check whether the dependency on auxiliary circulation can be reduced, check whether auxiliary circulation can be weaned, and wean the auxiliary circulation.

In addition, the auxiliary circulation control device 100 changes the amount of blood gas exchange in the artificial lung 120 according to a program while calculating the respiratory efficiency (blood gas exchange status index) based on body weight, so that the amount of gas exchange in the artificial lung 120 can be efficiently changed by the gas exchange amount control unit 176.

In addition, the auxiliary circulation control device 100 can reduce the amount of blood gas exchange in the artificial lung 120 in accordance with the recovery time during which dependency on auxiliary circulation decreases, so dependency on auxiliary circulation can be reduced while checking the recovery of vital lung function, or the auxiliary circulation device can be smoothly removed.

In addition, according to the auxiliary circulation control device 100, when a signal indicating that the blood gas exchange condition is inappropriate is received during gas exchange volume fluctuation control, the gas exchange volume fluctuation control is released (stopped) and the gas exchange volume is restored to the value before the gas exchange volume fluctuation control was started, so that auxiliary circulation using gas exchange volume fluctuation control can be performed safely.

In addition, according to the auxiliary circulation control device 100, the gas exchange status determination unit 173 outputs an alarm when the respiratory efficiency based on body weight (blood gas exchange status index) falls outside the set range while the program is being executed, so that the amount of blood gas exchange can be changed safely.

In addition, the auxiliary circulation control device 100 calculates the auxiliary circulation ratio (ECMO Rate), respiratory efficiency based on body weight (blood gas exchange status index), and determines the blood gas exchange status, and displays the results in real time on the graph display section 188 of the LCD touch panel 180, allowing the blood gas exchange status of patient P to be accurately understood as a trend.

In addition, according to the auxiliary circulation control device 100, the amount of carbon dioxide emitted in the artificial lung 120 and the natural lung (NL) is calculated based on the inhalation and exhalation of the artificial lung 120 and the inhalation and exhalation of the artificial ventilator 140, so that the amount of carbon dioxide emitted in the artificial lung 120 and the natural lung (NL) can be accurately calculated.
In addition, the oxygenation state of blood in the living lungs can be efficiently grasped.

Second Embodiment
Hereinafter, the auxiliary circulation (VA ECMO) according to the second embodiment of the present invention will be described with reference to FIGS.
Fig. 13 is a conceptual diagram for explaining the schematic configuration of the auxiliary circulation (V-A ECMO) according to the second embodiment of the present invention. The dotted lines in Fig. 13 indicate electric cables (some paths are omitted) connecting the auxiliary circulation control device 100 to each sensor, the artificial lung gas supply device, and the centrifugal pump driver.
FIG. 14 is a conceptual diagram for explaining an outline of blood circulation in a patient to whom assisted circulation (VA ECMO) is applied.
In FIG. 13, reference numeral 20 denotes an auxiliary circulation system (VA ECMO).

The second embodiment is an example in which, for example, an auxiliary circulation system (VA ECMO) 20 and an artificial ventilator 140 are connected to a patient (living body) P as shown in FIG.
In the second embodiment, a patient (living body) P is connected to, for example, an auxiliary circulation control device 100, an auxiliary circulation system (V-A ECMO) 20, an LCD touch panel 180, an artificial ventilator 140, and a pulse oximeter (blood oxygenation index measuring device) 148.

The auxiliary circulation system (V-A ECMO) 20 differs from the auxiliary circulation system (V-V ECMO) 10 in the following respects. As the rest is the same as in the first embodiment, the same reference numerals are used and the description is omitted.

That is, as shown in FIG. 13, the auxiliary circulation system (V-A ECMO) 20 differs in that it circulates blood drawn from a vein V1 of a patient (living body, human body) P using a centrifugal pump (blood feed pump) 115, and returns the blood after gas exchange in an artificial lung 120 to an artery A1 of the patient P. In this embodiment, the centrifugal pump (blood feed pump) 115 and the artificial lung 120 constitute an auxiliary circulation device.

Specifically, the second return line 113B is connected to the artery A1, and the blood sent out from the artificial lung 120 is transported (returned) from the return point P2 to the artery A1 via the second return line 113B.

The configuration of the auxiliary circulation control device 100 and the liquid crystal touch panel 180 can be set arbitrarily, but in the second embodiment, the auxiliary circulation control device 100 and the liquid crystal touch panel 180 are configured in the same manner as in the first embodiment.
In addition, the connection and operation of the auxiliary circulation control device 100 and the liquid crystal touch panel 180 are also similar to those in the first embodiment, so the same reference numerals are used and the description will be omitted.

Next, blood circulation in the case where an auxiliary circulation system (VA ECMO) is applied will be described with reference to FIG.
In a patient (living body) P to which an auxiliary circulation system (V-A ECMO) 20 is applied, blood that has been oxygenated in the living lungs (NL) and has an oxygen content CaO ₂ (NL), blood oxygen saturation (blood oxygenation status index) SaO ₂ (NL), and flow rate (spontaneous cardiac output) Q _CO , is pumped out by the heart to an artery A1, as shown in FIG. 14 .

On the other hand, in the assisted circulation (V-A ECMO), as shown in FIG. 14, the blood that has been oxygenated through gas exchange by the artificial lung (ML) 120 (oxygen content CaO ₂ (ML), blood oxygen saturation (blood oxygenation status index) SaO ₂ (ML), and flow rate (self-cardiac output) Q _ECMO) is pumped toward the artery A1 and joins with the blood pumped out from the heart at the return point P2.
The blood that joins at the reflux point P2 is mixed to become blood with an oxygen content _CaO2 , arterial blood oxygen saturation _SaO2 , and flow rate _QCIR (= _QCO + _QECMO ), and flows into the living tissue PS through the artery A1.

Then, the blood with oxygen content _CaO2 , oxygen saturation _SaO2 , and flow rate _QCIR that flows into the biological tissue PS becomes venous blood with an oxygen content _CvO2 and oxygen saturation _SvO2 reduced as oxygen is consumed metabolically in the biological tissue PS and carbon dioxide is produced.
The venous blood, whose oxygen content has been reduced to CvO ₂ and whose oxygen saturation has been reduced to SvO ₂ , flows at a flow rate Q _CIR through the vein V1 toward the heart and the vital lungs (NL).

Then, blood with an oxygen content of CvO ₂ , oxygen saturation of SvO _{2 and} flow rate Q _CIR flows through the vein V1 toward the heart and the vital lung (NL), and the venous blood with a flow rate Q _ECMO is withdrawn at the blood withdrawal point P1 and flows into the artificial lung (ML) of the auxiliary circulation system (VA ECMO) 20.

The blood that has been drawn and sent to the artificial lung (ML) is oxygenated in the artificial lung (ML) by gas exchange of carbon dioxide (CO ₂ ) to oxygen (O ₂ ), and is returned to the artery A1 at a reflux point P2.

On the other hand, the blood that is not withdrawn at the blood withdrawal point P1 at a flow rate Q _CO (=Q _CIR -Q _ECMO ) flows directly through the vein V1 toward the heart.
The blood is then oxygenated in the living lungs (NL) to become blood with an oxygen content CaO ₂ (NL), oxygen saturation SaO ₂ (NL), and flow rate (autocardiac output) Q _CO , and is sent to the artery A1.
In the blood circulation shown in FIG. 14, oxygenation is achieved in the artificial lung (ML) and the natural lung (NL) by an amount equal to [DaO ₂ -DvO ₂ ] shown in the above formula (101).

The blood circulation in the auxiliary circulation (VA ECMO) can be explained by focusing on either the auxiliary circulation flow rate Q _ECMO or the arterial blood oxygen content CaO ₂ .

[Focusing on auxiliary circulation flow rate Q _ECMO ]
When focusing on the auxiliary circulation flow rate Q _ECMO , in the blood circulation in the auxiliary circulation (V-A ECMO), the formulas (101) to (106) described in the auxiliary circulation (V-V ECMO) according to the first embodiment are established. The contents are the same as those in the first embodiment, so the description will be omitted.

(1) When focusing on arterial blood oxygen content _CaO2, if the arterial blood oxygen content of the blood flowing through the artery A1 to the biological tissue PS is _CaO2 and the circulating blood flow rate is _QCIR , the arterial blood oxygen transport amount _DaO2 can be expressed as the following formula (201).

ここで、補助循環（Ｖ－Ａ ＥＣＭＯ）を適用する場合、循環血流量Ｑ_ＣＩＲは、補助循環流量Ｑ_ＥＣＭＯと自己心拍出量Ｑ_ＣＯの和に等しいので、循環血流量Ｑ_ＣＩＲは、以下の数式（２０２）により表すことができる。

Here, when auxiliary circulation (VA ECMO) is applied, the circulating blood flow rate Q _CIR is equal to the sum of the auxiliary circulation flow rate Q _ECMO and the native cardiac output Q _CO , and therefore the circulating blood flow rate Q _CIR can be expressed by the following formula (202).

一方で、酸素の質量は保存されるから、動脈血酸素含有量ＣａＯ_２は、生体肺（ＮＬ）でガス交換された後の酸素含有量ＣａＯ_２（ＮＬ）、循環血流量Ｑ_ＣＩＲ、人工肺（ＭＬ）でガス交換された後の酸素含有量ＣａＯ_２（ＭＬ）、人工肺（ＭＬ）で酸素化された血液の流量Ｑ_ＥＣＭＯを用いて、以下の数式（２０３）のように表すことができる。

On the other hand, since the mass of oxygen is conserved, the arterial blood oxygen content _CaO2 can be expressed as the following formula (203) using the oxygen content after gas exchange in the natural lung (NL) _CaO2 (NL), the circulating blood flow rate _QCIR , the oxygen content after gas exchange in the artificial lung (ML) _CaO2 (ML), and the flow rate of oxygenated blood in the artificial lung (ML) _QECMO .

In addition, the total amount of carbon dioxide emission from the entire organism _V'CO2 is equal to the sum of the amount of carbon dioxide emission from the artificial lung (ML) _V'CO2 (ML) and the amount of carbon dioxide emission from the natural lung (NL) _V'CO2 (NL). Therefore, by substituting formula (203) into formula (201), and dividing the left side by the total amount of carbon dioxide emission from the entire organism _V'CO2 and the right side by (the amount of carbon dioxide emission from the natural lung (NL) _V'CO2 (NL) + the amount of carbon dioxide emission from the artificial lung (ML) _V'CO2 (ML)), it can be expressed as the following formula (204).

Here, since it is difficult to directly measure the intrinsic cardiac output _QCO in the above formulas (202) to (204), it is preferable to use a general estimated value of the amount of carbon dioxide discharged in the artificial lung (ML), _V'CO2 (ML).

The calculation results of the above formulas (203) and (204) may be selectively displayed by operating the third touch portion 189C, for example.
Next, when the value calculated by formula (205) by dividing the amount of oxygen transport _DaO2 by the total amount of carbon dioxide ( _CO2 ) discharge _V'CO2 (= _V'CO2 (NL) + _V'CO2 (ML)) is greater than a certain value, it is considered that the circulatory dynamics is safe, and if this value is set as the threshold value V _alarm (control target value), it can be expressed as _DaO2 / _V'CO2 > V _alarm . Then, focusing on the right side of formula (204), the following formula (205) is established.

数式（２０５）を、補助循環流量Ｑ_ＥＣＭＯに着目して変形すると、以下の数式（２０６）が得られる。

When formula (205) is modified with attention to the auxiliary circulation flow rate Q _ECMO , the following formula (206) is obtained.

また、ＣａＯ_２は、前述のように、次の数式（２０７）で近似される。

Moreover, as described above, _CaO2 is approximated by the following formula (207).

そして、数式（２０６）に数式（２０７）を当てはめて変形すると、数式（２０８）が導かれる。

Then, by applying formula (207) to formula (206) and transforming it, formula (208) is derived.

よって、数式（２０８）に基づいて、生体肺（ＮＬ）、人工肺（ＭＬ）の二酸化炭素の排出量の演算結果V’ＣＯ_２（ＮＬ）V’ＣＯ_２（ＭＬ）、動脈血酸素飽和度ＳａＯ_２、人工肺後の酸素飽和度ＳａＯ_２（ＭＬ）、及び自己心拍出量Ｑ_ＣＯから、各患者がＶ_{ａｌａｒｍ}（管理目標値）を満足するために必要な補助循環流量Ｑ_ＥＣＭＯを算出することが可能である。
ここで、流量Ｑ_ＣＯは、例えば、スワンガンツカテーテルの計測値、血圧波形解析、超音波エコー、ＭＲＩ等を用いて計測してもよい。
次に、補助循環流量Ｑ_ＥＣＭＯに着目した場合について説明する。
（２）補助循環流量Ｑ_ＥＣＭＯに着目する場合
静脈血の酸素運搬量を静脈血酸素運搬量ＤｖＯ_２とすると、酸素移動に関して酸素の質量は保存されることから、以下の数式（２０９）が成立する。

Therefore, based on formula (208), it is possible to calculate the auxiliary circulation flow rate _QECMO required for each patient to satisfy V _alarm (target management value) from the calculation results V'CO ₂ (NL) and V'CO ₂ (ML) of the carbon dioxide discharge rates from the natural lung (NL) and artificial lung ( _ML ), the arterial blood oxygen saturation SaO 2 , the oxygen saturation after the artificial lung SaO ₂ (ML), and the native cardiac output _QCO .
Here, the flow rate _QCO may be measured using, for example, a measurement value of a Swan-Ganz catheter, blood pressure waveform analysis, ultrasonic echo, MRI, or the like.
Next, a case in which the auxiliary circulation flow rate Q _ECMO is focused will be described.
(2) When focusing on auxiliary circulation flow rate Q _ECMO , if the oxygen transport rate of venous blood is defined as venous blood oxygen transport rate _DvO2 , the following formula (209) holds since the mass of oxygen is conserved with respect to oxygen transfer.

数式（２０９）を変形すると、以下の数式（２１０）が成立する。

By modifying the formula (209), the following formula (210) is obtained.

静脈血酸素運搬量ＤｖＯ_２は、静脈血酸素含有量ＣｖＯ_２×Ｑ_ＣＩＲであるから、数式（２１０）を変形すると、以下の数式（２１１）が導き出される。

Since the venous blood oxygen transport rate _DvO2 is the venous blood oxygen content _CvO2 × _QCIR , the following formula (211) is derived by transforming formula (210).

また、二酸化炭素総排出量V'ＣＯ_２＝人工肺の二酸化炭素排出量V'ＣＯ_２（ＭＬ）＋生体肺の二酸化炭素排出量V'ＣＯ_２（ＮＬ）、及び数式（２１１）から、以下に示す数式（２１２）が成立する。

Furthermore, total carbon dioxide emission amount V'CO ₂ = carbon dioxide emission amount from artificial lung V'CO ₂ (ML) + carbon dioxide emission amount from living lung V'CO ₂ (NL) and equation (211) give the following equation (212).

次に、酸素運搬量ＤａＯ_２を二酸化炭素（ＣＯ_２）総排出量VＣＯ_２（＝VＣＯ_２（ＮＬ）＋V’ＣＯ_２（ＭＬ））で除した数式（２０５）で算出される値が一定の値より大きいときには安全な循環動態と考えられるので、その値を閾値Ｖ_{ａｌａｒｍ}（管理目標値）として設定すると、ＤａＯ_２/ V’ＣＯ_２＞Ｖ_{ａｌａｒｍ}と表すことができる。そして、数式（２１２）の右辺に着目すると、以下に示す数式（２１３）が成立する。

Next, when the value calculated by formula (205) by dividing the amount of oxygen transport _DaO2 by the total amount of carbon dioxide ( _CO2 ) discharge _VCO2 (= _VCO2 (NL) + _V'CO2 (ML)) is greater than a certain value, it is considered that the circulatory dynamics is safe, and if this value is set as the threshold value V _alarm (control target value), it can be expressed as _DaO2 / _V'CO2 > V _alarm . Then, by focusing on the right side of formula (212), the following formula (213) is established.

補助循環流量Ｑ_ＥＣＭＯに着目して数式（２１３）を変形すると、以下の数式（２１４））が導き出される。

When equation (213) is modified with attention to the auxiliary circulation flow rate Q _ECMO , the following equation (214) is derived.

ここで、ＣｖＯ_２＝（（１．３４×Ｈｂ×ＳｖＯ_２）／１００）＋０．００３１×ＰｖＯ_２
であり、右辺第２項は第１項と比較して微少量であることから
ＣｖＯ_２ ≒（（１．３４×Ｈｂ×ＳｖＯ_２）／１００）
と省略できる。したがって、式（２１４）は、式（２１５）のように変形することができる。

Here, _CvO2 = ((1.34 x Hb x _SvO2 )/100) + 0.0031 x _PvO2
Since the second term on the right side is a very small amount compared to the first term, CvO ₂ ≈ ((1.34 × Hb × SvO ₂ )/100)
Therefore, equation (214) can be transformed into equation (215).

よって、数式（２１５）に基づいて、生体肺（ＮＬ）、人工肺（ＭＬ）の二酸化炭素の排出量の演算結果V’ＣＯ_２（ＮＬ）V’ＣＯ_２（ＭＬ）と、生体肺、人工肺（ＭＬ）の酸素摂取、静脈血酸素飽和度ＳｖＯ_２、及び自己心拍出量Ｑ_ＣＯから、各患者がＶ_{ａｌａｒｍ}（管理目標値）を満足するために必要な補助循環流量Ｑ_ＥＣＭＯを算出することが可能である。

Therefore, based on formula (215), it is possible to calculate the auxiliary circulating flow rate QECMO required for each patient to satisfy V _alarm (target management value) from the calculation results V'CO ₂ (NL) V'CO ₂ (ML) of the carbon dioxide discharge rates of the vital lung (NL) and the artificial lung (ML), the oxygen intake of the vital lung and the artificial lung (ML), the venous blood oxygen saturation SvO ₂ , and _the native cardiac output _QCO .

The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

For example, the auxiliary circulation control device 100 and the liquid crystal touch panel 180 shown in the above embodiment are merely examples, and the blood gas exchange status indicators and gas exchange amount parameters calculated or displayed can be set arbitrarily.
In addition, in the above embodiment, the auxiliary circulation control device 100 has been described as being applied to the control of the auxiliary circulation (V-V ECMO) 10 and the auxiliary circulation (V-A ECMO) 20, but it may also be applied to the control of the auxiliary circulation (V-V-A ECMO), for example.

In the above embodiment, the blood gas exchange status index is described as using the ECMO rate and the respiratory efficiency based on body weight. However, for example, the spontaneous rate may be used instead of or in addition to the ECMO rate and the respiratory efficiency based on body weight.

In addition, in the above embodiment, the case where the artificial ventilator 140 is used together with the auxiliary circulation system 10, 20 has been described, but whether or not the artificial ventilator 140 is used can be set as desired, and instead of the artificial ventilator 140, the carbon dioxide emission amount and oxygen intake amount may be calculated based on the inhalation and exhalation when breathing using an oxygen mask or the like.

In addition, in the above embodiment, the gas exchange volume control unit 176, which changes the gas exchange volume, operates according to a program stored in the third memory unit 179 to change the gas supply volume of the artificial lung gas supply device 122, thereby changing the oxygen content of the artificial lung intake gas, and the blood flow rate by the centrifugal pump (blood supply pump) 115 changes in response to the flow rate of the artificial lung intake gas. However, for example, the oxygen concentration of the artificial lung intake gas may be changed to change the oxygen content of the artificial lung intake gas.
In addition, the oxygen content of the artificial lung inhalation gas may be changed in accordance with the blood flow rate of the centrifugal pump 115.

In the above embodiment, the gas sensor used to calculate the contribution of the artificial lung 120 in the auxiliary circulation circuit 10, the blood gas exchange status index, and the gas exchange volume parameter is a carbon dioxide concentration sensor connected to the artificial lung 120 and the artificial ventilator 140. However, for example, the calculation may be performed using an oxygen concentration sensor connected to the artificial lung 120 and the artificial ventilator 140. In addition, both a carbon dioxide concentration sensor and an oxygen concentration sensor may be used.

In addition, the configuration and placement positions of the artificial lung inhalation gas sensor 125, the artificial lung exhalation gas sensor 126, the artificial ventilator inhalation gas sensor 142, and the artificial ventilator exhalation gas sensor 144 can be set arbitrarily.

In addition, for example, a sampling circuit (not shown) may be provided in the artificial lung inhalation line 123 and the artificial lung exhalation line 124, so that a single gas sensor serves as both the patient inhalation gas sensor 142 and the patient exhalation gas sensor 144.

In addition, in the above embodiment, the artificial lung intake sensor 125, the artificial lung exhaust gas sensor 126, the patient intake gas sensor 142, and the patient exhaust gas sensor 144 are described as calculating the carbon dioxide emission amount as the gas exchange amount parameter based on the concentration of carbon dioxide exchanged. However, the gas exchange amount parameter may be calculated as the content of other gases (e.g., anesthetic gas, etc.) contained in the respiratory gas whose content of carbon dioxide and oxygen can be determined, for example.

In addition, in the above embodiment, the auxiliary circulation control device 100 is described as having an auxiliary circulation ratio calculation unit 171, a blood gas exchange status index calculation unit 172, and a gas exchange status determination unit 173. However, for example, whether or not the auxiliary circulation ratio calculation unit 171 and the gas exchange status determination unit 173 are provided may be set arbitrarily.

In addition, in the above embodiment, when the gas exchange status determination unit 173 determines that the gas exchange status is inappropriate, it outputs a signal to the gas exchange amount control unit 176 and outputs an alarm to the liquid crystal touch panel 180. However, it is possible to set arbitrarily whether or not to output a signal to these.

In the above embodiment, the gas exchange amount control unit 176 receives a signal from the gas exchange status determination unit 173 indicating that the blood gas exchange status is inappropriate, and releases (stops) the control for changing the gas exchange amount and restores the gas exchange amount. However, it is possible to arbitrarily set whether or not the gas exchange amount is changed to a set state (e.g., restored). Also, instead of restoring, the gas exchange amount may be changed to a preset value.

In addition, in the above embodiment, the auxiliary circulation control device 100 has been described as calculating the amount of carbon dioxide discharged in the living lung (NL) by volume capnoanalysis, but, for example, the amount of carbon dioxide discharged in the living lung (NL) calculated by volume capnoanalysis may be input from the outside.

For example, in the above embodiment, the blood pump is a centrifugal pump 115, but instead of the centrifugal pump 115, a roller pump, in which a rotating roller rotates and squeezes a flexible tube to draw in and send out blood, may be used.

In addition, in the above embodiment, mathematical expressions were used to explain the various calculations in the auxiliary circulation control device 100, but it goes without saying that the above mathematical expressions are only examples, and other mathematical expressions or calculation methods may be used without being limited to the above mathematical expressions.

In addition, in the above embodiment, an example of the schematic configuration of a flowchart for explaining the operation of the auxiliary circulation control device 100 has been described, but control may also be performed using a method (algorithm) other than the above flowchart.
Furthermore, the functions and signal exchanges of each block in the block diagram of the auxiliary circulation control device 100 shown in the above embodiment are merely examples, and are not limited to the above blocks.

In addition, in the above embodiment, the auxiliary circulation control device 100 has been described as being applied to monitoring the auxiliary circulation of a patient (human body, living organism) P, but it may also be applied to the auxiliary circulation of an animal (living organism) instead of the human body P, for example.

The auxiliary circulation control device and auxiliary circulation system of this invention can efficiently grasp the change in the blood gas exchange status index when the amount of blood gas exchange by the artificial lung changes, and therefore can be used industrially.

P Patient (living body, human body)
10. Assisted circulatory system (V-V ECMO)
20. Assisted circulatory system (V-A ECMO)
100 Auxiliary circulation control device 111 Blood removal line 112 Blood supply line 113 Circulation line 115 Centrifugal pump (blood supply pump)
116 Flow rate sensor 118 Blood supply auto clamp 119 Recirculation clamp 120 Artificial lung 121 Artificial lung main body 122 Artificial lung gas supply device 125 Artificial lung inhalation gas sensor 126 Artificial lung exhalation gas sensor 140 Artificial ventilator 142 Artificial ventilator inhalation gas sensor 144 Artificial ventilator exhalation gas sensor 171 Auxiliary circulation ratio calculation unit 172 Blood gas exchange status index calculation unit 173 Gas exchange status determination unit (blood gas exchange status determination unit)
174 Oxygen saturation display unit (blood oxygenation index display unit)
176 Gas exchange amount control unit 178A Artificial lung intake gas control unit 178B Blood pump control unit 180 Liquid crystal touch panel

Claims (8)

An auxiliary circulation control device that is connected to a living body, controls an auxiliary circulation device that sends blood drawn from the living body to an artificial lung by a blood sending pump and exchanges blood with gas in the artificial lung in parallel with the living lung,
A gas exchange amount control unit that controls the amount of blood gas exchanged in the oxygenator, the gas exchange amount control unit having an oxygenator intake gas control unit that supplies gas to the oxygenator, and a blood pump flow rate control unit that controls the flow rate of blood sent to the oxygenator, and changes the amount of gas exchange in the oxygenator;
a blood gas exchange status index calculation unit that calculates a blood gas exchange status index in the living body;
a blood gas exchange status determination unit for determining whether the blood gas exchange status index is within a set numerical range;
Equipped with
The blood gas exchange status determination unit
The blood gas exchange status index is calculated when the amount of blood gas exchange in the artificial lung is changed, and whether or not the reduction in dependency on auxiliary circulation performed by the artificial lung is appropriate is determined based on whether or not the blood gas exchange status index is within a set numerical range due to the reduction in auxiliary circulation performed by the artificial lung.
An auxiliary circulation control device characterized by: An auxiliary circulation control device that is connected to a living body, controls an auxiliary circulation device that sends blood drawn from the living body to an artificial lung by a blood sending pump and exchanges blood with gas in the artificial lung in parallel with the living lung,
A gas exchange amount control unit that controls the amount of blood gas exchanged in the oxygenator, the gas exchange amount control unit having an oxygenator intake gas control unit that supplies gas to the oxygenator, and a blood pump flow rate control unit that controls the flow rate of blood sent to the oxygenator, and changes the amount of gas exchange in the oxygenator;
a blood gas exchange status index calculation unit that calculates a blood gas exchange status index in the living body;
Equipped with
The gas exchange amount control unit is
The amount of gas exchange of blood in the oxygenator can be changed according to a preset program,
The blood gas exchange status index calculation unit
The gas exchange amount control unit calculates the blood gas exchange status index when the blood gas exchange amount in the oxygenator is changed according to the program,
The gas exchange amount control unit is
When changing the amount of gas exchange of blood in the artificial lung, the amount of gas exchange of blood in the artificial lung is reduced in correspondence with a recovery time during which the dependency of the living lung on auxiliary circulation is reduced.
An auxiliary circulation control device characterized by: 3. The auxiliary circulation control device according to claim 2 ,
The gas exchange amount control unit is
An auxiliary circulation control device characterized by changing the amount of gas exchange of blood in the artificial lung, and when a predetermined condition for stopping the operation of reducing the dependence on auxiliary circulation is detected, restoring the blood flow rate sent to the artificial lung and the oxygen content of the artificial lung intake gas supplied to the artificial lung to a predetermined state. The auxiliary circulation control device according to claim 2 or 3 ,
4. An auxiliary circulation control device, comprising: a blood gas exchange status index calculating unit that calculates a blood gas exchange status index that is outside a set numerical range and outputs an alarm when the blood gas exchange status index calculated by the blood gas exchange status index calculating unit falls outside a set numerical range. The auxiliary circulation control device according to any one of claims 1 to 4 ,
The blood gas exchange status index calculation unit
An auxiliary circulation control device characterized by performing calculations at set time intervals. The auxiliary circulation control device according to any one of claims 1 to 5 ,
The gas exchange amount control unit is
An auxiliary circulation control device characterized by changing at least one of the oxygen content of the artificial lung intake gas supplied to the artificial lung and the flow rate of blood sent to the artificial lung when changing the amount of gas exchange of blood in the artificial lung. The auxiliary circulation control device according to any one of claims 1 to 5 ,
The gas exchange amount control unit is
2. An auxiliary circulation control device, comprising: a blood gas exchange status index calculating unit for calculating a blood gas exchange status index; a blood gas exchange status index calculating unit for calculating a blood gas exchange status index; An auxiliary circulation system comprising the auxiliary circulation control device according to any one of claims 1 to 7 .

Images