JP2002272848A - Anesthesia equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anesthetizing apparatus capable of reducing a labor for sterilizing the apparatus and grasping a precise inhalation quantity by reducing the burden of monitoring and safely performing low flow rate anesthesia. SOLUTION: The anesthetizing apparatus includes a circulation circuit having a chamber including bellows, an inhalation channel for feeding gas in the bellows to a patient channel through which the breath of the patient flows via an inhalation valve and an exhalation channel connected to the patient channel to allow a carbon dioxide absorbing canister to pass through via an exhalation valve. The apparatus includes a driving circuit part having an artificial respirator and a bag for feeding gas into the chamber including the bellows, a changeover valve for the changeover of the connection between each of the artificial respirator and the bag and the inside of the chamber, and a fresh gas switch valve provided at a channel for feeding the fresh gas into the bellows, connected to the bag via the changeover valve and guiding the fresh gas to the bag in the inhalation phase by the artificial respirator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anesthesia apparatus for inhaling anesthesia on a human or animal.

[0002]

2. Description of the Related Art The safe operation at present depends largely on advances in anesthesia technology. But,
Anesthesia machines that often seem to be almost complete still have major problems.

At present, semi-closed anesthesia (high-flow anesthesia) is the mainstream of anesthesia in Japan, and the anesthesia circuit, which is a means of supplying anesthetic gas, is supplied to the anesthesia circuit from 5 to 8 minutes per minute.
One liter of fresh anesthetic gas was largely discarded outside the anesthetic circuit without being ingested by the patient. In recent years, aspiration systems aimed at eliminating this discarded anesthetic gas from the operating room have become widespread,
There is no danger that the operating staff will inhale the anesthetic gas in the operating room, but the excess anesthetic gas that is sucked out will be discharged into the atmosphere, so the laughing gas contained in the anesthetic gas and CFC-based A new problem has been pointed out that anesthetic gas (halothane, isoflurane, etc.) destroys the ozone layer and causes global warming.

[0004] As an effective method for alleviating this problem, a so-called low flow anesthesia, in which the flow rate of fresh gas supplied from the anesthesia device main body is reduced to 2 liters or less per minute, is introduced. However, in the conventional anesthesia apparatus, even if an attempt is made to adopt this low flow anesthesia, a difference occurs between the components of the fresh gas and the components in the anesthesia circulation circuit, and it is necessary to maintain appropriate ventilation conditions and depth of anesthesia for the patient. The operation becomes very complicated as compared with the case of performing semi-closed anesthesia, and there is a situation that it is difficult to actually use it.

[0005] Therefore, the present applicant has determined that it is essential to directly monitor the metabolism of the patient in order to realize low flow anesthesia. In the provided mixing chamber, an oxygen sensor, a carbon dioxide gas sensor, and an anesthesia gas sensor are respectively provided, and a flow rate sensor is provided in a patient flow path connecting the expiratory flow path and the inspiratory flow path to a patient. Calculate the oxygen uptake and carbon dioxide emission for each respiration of the patient during anesthesia from the detected values of the anesthesia, and calculate the anesthetic agent balance from the detected values of the anesthesia gas sensor and flow rate sensor, and calculate those calculated values. Based on the above, it is important to anesthetize a patient by determining the amount of fresh gas supplied from the anesthesia machine main body to the anesthesia circulation circuit, the component ratio, and the ventilation volume of a ventilator. I discovered that is, Japanese Patent Application No. 11
Patent application for -280687.

Another conventional technique is disclosed in Japanese Patent Laid-Open No. 7-15 / 1995.
Japanese Patent No. 5380 discloses a blending unit for blending fresh gas with an anesthetic, laughing gas, oxygen, etc., a circulation circuit for supplying the blended fresh gas to a patient, and a discharge unit for discharging excess gas from the circulation circuit. An anesthesia apparatus comprising: a discharge pump connected to a discharge unit for forcibly discharging an arbitrarily set gas amount to the outside of the circulation circuit; and a concentration of an anesthetic, a concentration of oxygen, and a gas volume in the circulation circuit. An anesthesia device including an electronic control device that detects and controls a blending unit is disclosed. This publication describes that the control of the mixing ratio of fresh gas and the control of the supply amount in the mixing section can be performed quickly and accurately by an automatic control device, and low flow anesthesia can be performed.

Further, in Japanese Patent Application Laid-Open Nos. Hei 10-212282 and Hei 10-212283, an intake valve, an exhalation valve, and a carbon dioxide absorbing device are provided at an intermediate portion of a circulation circuit, and at the end, extremely deformed inside a pressure chamber. A circuit for an anesthesia machine provided with an easy bellows and an oxygen flush circuit for the anesthesia machine are disclosed. In the prior art disclosed in these publications, a bellows-containing chamber (also referred to as a bellows-in chamber) is provided in the circulation circuit, so that air is supplied from the same circuit even when switching to either the automatic / manual mode. Therefore, the gas concentration in the circuit does not change, and the movement of the bellows is visible for each stroke in the transparent pressure chamber, so that the ventilation state can be clearly grasped.

[0008]

However, when an attempt is made to perform low-flow anesthesia or completely closed anesthesia using an anesthesia apparatus based on the above-mentioned prior art, the oxygen uptake of the patient increases during anesthesia, or the circulation circuit is increased. If there is a leak, the amount of gas in the circulation circuit may be insufficient, and it is necessary to constantly monitor the gas. In order to cope with such abnormalities, conventionally, a negative pressure safety valve that monitors the pressure in the circulation circuit and sucks in the outside air when the pressure in the circuit becomes negative is provided. There was a problem that the concentration and the anesthetic concentration decreased. In addition, when low-flow anesthesia is performed, the rate of absorbing carbon dioxide from the patient's exhalation and circulating it again as inhalation increases, so that the temperature and humidity in the circulation circuit increase and bacteria are likely to be generated. Become. Therefore, in order to prevent the propagation of bacteria, there are many occasions where it is necessary to sterilize the circulation circuit. However, conventional anesthesia devices include a circuit portion that is in direct contact with the patient's breath,
Since the other drive circuit portions are integrally formed, the circulation circuit portion and the drive circuit portion must be sterilized at the same time, and the sterilization operation requires much labor and time. Further, among the conventional examples described above, those provided with a bellows-containing chamber have a particularly low flow anesthesia since the amount of fresh gas sent from the anesthesia gas supply system is added to the amount of gas sent from the ventilator. However, there is a problem that an accurate intake amount cannot be grasped.

The present invention has been made in view of the above circumstances, and reduces the burden of monitoring, can perform low flow anesthesia safely, and reduces the labor of sterilization by adopting a structure that can sterilize only the circulation circuit portion. It is another object of the present invention to provide an anesthesia apparatus that can accurately determine the amount of inspired air.

[0010]

In order to achieve the above-mentioned object, the present invention provides an anesthesia machine main body which mixes at least laughing gas, oxygen gas and a volatile anesthetic and supplies it as a fresh gas; A fresh gas supplied from the main body is mixed with the circulating air after absorbing and removing carbon dioxide from the exhalation of the patient, and an anesthesia circulating circuit that mixes the circulating air and the fresh gas and sends the mixed gas to the patient as inhalation, In an anesthesia apparatus for sending an inspiration containing an anesthetic gas to a patient from the anesthetic circulation circuit to anesthetize the patient, the anesthesia circulation circuit includes: a chamber containing a bellows; It has an inspiratory flow path for sending to a patient flow path through which air flows, and an exhalation flow path connected to the patient flow path and for sending the patient's exhalation through the carbon dioxide absorption canister via an exhalation valve and sending it into the bellows. Circulation circuit ; And ventilator and bag for supplying gas into the chamber of the bellows filled chamber,
A switching valve for switching the connection between each of the ventilator and the bag and the inside of the chamber, and a flow path for sending fresh gas from the anesthesia device body into the bellows; And a drive circuit unit having a fresh gas on-off valve for connecting the fresh gas to the bag during the inspiratory phase of the ventilator.

In the anesthesia apparatus according to the present invention, the ventilator is provided with a surplus gas discharge valve for discharging surplus gas, and one end is connected to a flow path connecting the exhalation valve and the carbon dioxide gas absorbing canister. A surplus gas discharge flow path may be provided in which the other end is connected to the surplus gas discharge valve via a pop-off valve that is opened by an APL valve. In the anesthesia apparatus of the present invention, the bellows-containing chamber may be provided with a sensor for detecting an upper end position or a projected area of the bellows. Further, in the anesthesia device, receiving a signal from the sensor, monitors whether the gas amount in the circulation circuit is appropriate, displays it on a screen, and issues an alarm when a measured value deviates from a preset value. A monitoring device configured as described above may be provided. Further, in the anesthesia apparatus of the present invention, a connector may be provided in a flow path connecting the drive circuit unit and the circulation circuit, and the circuit may be detachable from the drive circuit unit. The bellows-containing chamber may have a structure in which the bellows can be taken out of the chamber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an entire anesthesia apparatus showing an embodiment of the present invention. As shown in this figure,
The anesthesia apparatus 1 includes an anesthesia machine main body 2 which supplies at least a mixture of laughing gas, oxygen gas and volatile anesthetic, and a laughing gas, oxygen gas and volatile anesthetic supplied from the anesthesia machine main body 2. Is mixed with the circulating air after absorbing and removing carbon dioxide from the exhalation of the patient A, and the mixture of the mixed gas and the fresh gas is sent to the patient A as inhaled air. It has.

The anesthesia machine main body 2 includes a gas supply unit 10 for supplying oxygen gas, laughing gas and air, and a flow meter 11 for controlling and measuring the flow rate of the gas supplied from the gas supply unit 10.
And a vaporizer 12 for supplying a volatile anesthetic in the gas in a vaporized state. In addition, the vaporizer 12 does not necessarily need to be provided in the anesthesia machine main body 2 and may be provided in the anesthesia circulation circuit 3.

The gas supply unit 10 controls the pressure of oxygen gas, laughing gas, and air supplied from the outside,
The pressure at that time is displayed. Note that, when the supply of oxygen gas is insufficient, the supply of laughing gas can be automatically stopped. The flow meter 11
A conventionally used rotameter-type flow meter may be used, but it is preferable to use an electronic flow meter using a mass flow meter because accurate measurement is possible. Among them, those that can measure with high accuracy in the total flow rate range of 2 liters per minute or less so that it can respond to low flow anesthesia,
More preferred.

[0015] The vaporizer 12 is a volatile anesthetic.
Halothane, enflurane, isoflurane, sevoflurane, and desflurane, which has recently attracted attention, are sent to a vaporization chamber by a microinjection pump so as to have a predetermined concentration, and the volatile anesthetic vaporized here is supplied to the gas supply unit 10. Is mixed with the anesthetic gas sent from the company.

The anesthesia circulation circuit 3 includes a bellows-containing chamber 26, an inspiratory flow path 21 for sending the gas in the bellows 24 to a patient flow path 23 through which the respiratory air of the patient A flows through an inspiratory valve 27, A circulation circuit 4 having an exhalation flow path 22 connected to the flow path 23 and passing the exhalation of the patient A through the carbon dioxide absorption canister 31 through the exhalation valve 30 and into the bellows 24; A ventilator 40 and a bag 29 for supplying gas into the chamber 26a, a switching valve 28 for switching the connection between each of the ventilator 40 and the bag 29 and the inside of the chamber 26a, and a bellows for fresh gas from the anesthetic machine body 2 It is provided in a flow path 36 for feeding into the inside 24, and is connected to a bag 29 via a switching valve 28, and fresh gas is supplied to the bag 29 in the inspiratory phase by the ventilator 40. Ku and a drive circuit portion 5 having a fresh gas on-off valve 25.

The drive circuit section 5 further includes an artificial respirator 4
0, through a flow path 50, 51, a surplus gas discharge valve 41 that opens to discharge surplus gas through a flow path 52 when the pressure in the system rises, and a flow connecting the exhalation valve 30 and the carbon dioxide absorption canister 31. When the pressure in the passage 22 rises, the passage 39
A pop-off valve 33 that opens to allow gas to escape through
A surplus gas discharge flow provided in a flow path 47 connected to the flow path 39 and having an APL valve 42 that can be adjusted so that surplus gas flows to the surplus gas discharge valve 41 through the flow paths 48, 49, and 51 by adjusting the opening degree. Road 6 is provided.

The bellows-containing chamber 26 (also referred to as a bellow-in chamber) is a transparent chamber 2
6a, a bellows 24 is arranged in the bellows 2a.
4 is connected to one end of the intake channel 21 and one end of a channel 35 on the downstream side of the carbon dioxide absorption canister 35. This flow path 35 joins a flow path 36 downstream of the fresh gas on-off valve 25 on the way. Therefore,
Inside the bellows 24, the carbon dioxide absorption canister 3
The regenerated expiration sent in a state in which the carbon dioxide gas has been removed through 1 and fresh gas flow in, while the gas in the inside is sent to the patient A through the inspiratory flow path 21.

In the chamber 26a, (1) flow paths 50, 49, 46, 45, 39
And 37 from the ventilator 40, or (2) the gas from the bag 29 through the flow paths 44, 45, 39 and 37.

The bellows 24 has a structure capable of extremely flexibly expanding and contracting according to the pressure difference between the internal pressure and the pressure in the chamber 26a. Therefore, if the degree of expansion and contraction of the bellows 24 inside is seen through the transparent chamber 26a, the respiratory state of the patient A can be easily confirmed. The bellows 24 connects the circulation circuit 4 to the drive circuit unit 5.
When the circulation circuit 4 is separated from the chamber 26 and sterilized, it is preferable that the circulation circuit 4 be configured to be easily taken out from the chamber 26a. Such a mounting structure is, for example, a bellows 2
A structure in which the bottom cover to which the bottom cover 4 is fixed is inserted into an opening provided at the bottom of the chamber 26a, the bottom cover is screwed and fixed, and the packing is hermetically sealed can be adopted.

At the top of the bellows-containing chamber 26,
A sensor 32 for detecting the position of the upper end of the bellows 24 inside the chamber 26a is provided. As the sensor 32, an ultrasonic sensor, a magnetic sensor, and the like that can measure a distance from a fixed position to an upper end of the bellows 24 without contact.
Any of optical sensors such as infrared light can be used. Note that, instead of the sensor 32, the chamber 26a
A sensor of a type that detects the projected area of the bellows 24 in the inside may be used. The sensor 32 receives a signal from the sensor 32, monitors whether the gas amount in the circulation circuit 4 is appropriate, displays the gas amount on the screen, and sets the measured value (the upper end position of the bellows) in advance. It is preferable to provide a monitoring device configured to generate an alarm when the value deviates. In the case of completely closed anesthesia, it is also possible to automatically control the flow rate of fresh gas sent from the anesthesia machine main body 2 so that the measured value becomes a preset value.

The inside of the bellows 24 and the patient flow path 23 are connected,
An inspiratory valve 27 provided in the middle of the inspiratory flow path 21 through which inspiratory flow to the patient A flows allows the flow of gas (inspiratory) from the bellows 24 to the patient flow path 23 and further to the patient A, but the reverse flow. Operates to regulate. The exhalation valve 30 provided in the middle of the exhalation flow path 22 through which the exhalation from the patient A flows from the patient flow path 23 into the bellows 24, transmits the exhalation from the patient to the bellows 24 through the carbon dioxide absorption canister 31.
It operates to allow inflow of gas (expiration) but restricts the reverse flow. The patient flow path 23 connecting the patient A, the inspiratory flow path 21 and the expiratory flow path 22,
A coaxial double tube structure may be used.

A carbon dioxide absorption canister 31 provided between the downstream side of the exhalation valve 30 and the bellows 24 absorbs and removes carbon dioxide from the exhalation of the patient A sent through the exhalation flow path 22 and the flow path 34. This is for supplying regenerated expiration gas not containing carbon dioxide gas to the bellows 24 through the flow path 35. The inside of the carbon dioxide absorption canister 31 is filled with a carbon dioxide absorbent such as soda lime. In the case of low flow anesthesia, a large amount of carbon dioxide is used because the amount of absorbed carbon dioxide increases.

The respirator 40 can select either a capacity limit type in which capacity is controlled or a pressure limit type in which pressure is controlled. The flow path 50 connected to the ventilator 40 is branched into a flow path 49 on the chamber 26 a side and a flow path 51 connected to the surplus gas discharge valve 41. The surplus gas discharge valve 41 is closed only during inhalation by the respirator, and otherwise discharges surplus gas to the outside of the system through the flow path 52. The discharged gas is led to a rejection device.

The bag 29 is a compressible bag for sending inhalation to the patient A. Bags of various sizes are prepared according to the supply amount of inspiration to be sent to the patient A, and can be replaced as appropriate. Has become. In the present invention, in the inspiratory phase by the ventilator 40, the fresh gas sent through the flow path 2a is supplied to the fresh gas on-off valve 25, the flow path 43, the switching valve 2
8 and the flow path 44 to the bag 29,
9 is stored. With this configuration, the amount of fresh gas sent from the anesthesia machine main body 2 is not added to the amount of gas sent out from the bellows-containing chamber 26, and the amount of intake air independent of the amount of fresh gas flow can be set. Becomes

The fresh gas on-off valve 25 is provided with a flow path 2 a for sending fresh gas from the anesthesia machine main body 2 and a bellows 24
The flow passage 2a is provided between the flow passages 36 for sending the air to the bag 29 through the switching valve 28.
And joined. The fresh gas on-off valve 25 is closed during the inspiratory phase by the ventilator 40, and the fresh gas sent through the flow path 2a is sent to the bag 29 through the flow path 43, the switching valve 28, and the flow path 44. The fresh gas stored in the bag 29 and opened in the expiratory phase by the ventilator 40 and sent through the flow path 2a and the fresh gas stored in the bag 29 are passed through the flow path 36 into the bellows 24. Operate to be sent.

The switching valve 28 is for switching between an automatic ventilation mode using the ventilator 40 and a manual ventilation mode using the bag 29. This switching valve 28 includes flow paths 43 and 44 from the fresh gas on-off valve 25 to the bag 29,
The respective flow path ends of flow paths 46 and 45 on the way from the ventilator 40 to the chamber 26a are connected.
The switching valve 28 is connected to the flow path 4 in the automatic ventilation mode.
3 and 44, and the flow paths 46 and 45 are connected, while in the manual ventilation mode, the flow paths 44 and 45 are connected.
Each flow path can be switched so as to connect.

The pop-off valve 33 is connected to the exhalation flow path 22 and opens when the amount of gas in the circuit of the circulation circuit 4 increases and exceeds a certain pressure.
It operates to discharge the surplus gas discharge valve 41 through 46, 49 and 51. APL (Adjustable Pressure
Limiting) valve 42 controls the amount of gas discharged from flow path 47 to flow path 48 by opening and closing a control valve to prevent excessive pressure from being applied to circulation circuit 4 in the manual ventilation mode.

In this anesthesia apparatus 1, as described above,
The bellows-containing chamber 26 has a structure in which the bellows 24 can be easily removed from the chamber 26a, and a pipe section having an easy-to-detach connector is formed immediately before the pop-off valve 33 of the flow path 22. In addition, the circulation circuit 4 that is easily contaminated can be easily separated from the drive circuit unit 5. By allowing only the circulation circuit 4 to be separable in this manner, only when the necessity of sterilizing the anesthesia circulation circuit occurs periodically or when the patient is replaced, only the circulation circuit 4 through which the patient's respiratory gas circulates is used. Since it can be subjected to sterilization processing such as removal, gas sterilization, and autoclave sterilization, labor and time for the sterilization processing can be greatly reduced. Further, it is possible to increase the frequency of sterilization as compared with the related art.

Here, an anesthesia method using the anesthesia apparatus will be described with reference to FIGS. In FIGS. 2 to 5, the flow path through which the gas flows is indicated by a solid line, and the flow path through which the gas does not flow is indicated by a broken line.

(1) Intake phase by automatic ventilation In FIG. 1, oxygen gas, laughing gas and air are supplied from the outside to the gas supply unit 10 of the anesthesia machine main body 2, where the pressure is adjusted. The flow rate of the anesthetic gas is measured by the flow meter 11, and it is determined whether or not the flow rate is a preset value. An anesthetic gas having a predetermined flow rate measured by a flow meter is mixed with a volatile anesthetic in the vaporizer 12 and supplied to the anesthetic circulation circuit 3 through the flow path 2a as a fresh gas.

In the inspiratory phase by the automatic ventilation shown in FIG. 2, the ventilator 40 operates so as to discharge a certain amount of gas. This gas is supplied to the flow passages 50, 49, 46 and the switching valve 2
8, the fluid is supplied to the chamber 26a of the bellows-containing chamber 26 through the flow paths 45, 39 and 37. At the start of this inspiratory phase, regenerated expiration in which carbon dioxide is absorbed and removed from the exhalation of patient A and fresh gas are stored in the bellows 24 in the bellows-containing chamber 26, and the upper end of the bellows 24 is relatively positioned. Is on the top. This bellows 24
Is constantly detected by the sensor 32, and a detection signal from the sensor 32 is sent to the monitoring device, and the bellows 2
The state of No. 4 is constantly monitored. Further, the movement of the bellows 24 in the transparent chamber 26a can be well observed with the naked eye. Ventilator 40 to chamber 26
When the gas is sent into a, the bellows 26 contracts in accordance with the amount of the gas, and the gas in the bellows reaches the patient flow path 23 through the intake flow path 21 and the intake valve 27 and is sent to the patient A.

In this intake phase, the fresh gas on-off valve 2
5 is closed. Fresh gas, which is constantly supplied in a constant amount through the passage 2a, reaches the bag 29 from the fresh gas on-off valve 25 via the flow path 43, the switching valve 28, and the flow path 44, and is stored in the bag 29.

(2) Expiration phase by automatic ventilation FIG. 3 is a view for explaining the flow of gas in the expiration phase by automatic ventilation using an artificial respirator. In the expiration phase, expiration from the patient A flows from the patient flow path 23 to the expiration valve 30 and the expiration flow path 22.
And is fed into the carbon dioxide absorption canister 31 through the flow path 34. The exhaled gas contacts the carbon dioxide gas absorbent such as soda lime filled in the carbon dioxide gas absorbing canister 31 to remove the carbon dioxide gas, and is discharged from the carbon dioxide gas absorbing canister 31 as regenerated breath containing no carbon dioxide gas. The regenerated breath is supplied into the bellows 24 through the flow path 35.

In this expiration phase, the fresh gas on-off valve 25
Is opened, and the fresh gas sent from the anesthesia machine main body 2 through the flow path 2a and the fresh gas stored in the bag 29 are sent into the bellows 24 along with the regenerated expiration via the flow paths 36 and 35. The upper end position of the bellows 24, which was relatively lower at the start of the expiration phase, rises as the gas flows.

In the automatic ventilation using the ventilator 40, the above-mentioned inspiratory phase and expiratory phase are alternately repeated to recirculate and use the expiration of the patient A, thereby greatly reducing the amount of fresh gas to be newly supplied. Low flow anesthesia can be performed. The state of ventilation in the circulation circuit 4 can be easily grasped by observing the movement of the bellows 24 of the bellows-containing chamber 26. Further, the upper end position of the bellows 26 is detected by the sensor 32, displayed on the monitor of the monitoring device, and recorded, whereby the respiratory condition of the patient A can be monitored. Further, when the upper end position of the bellows 24 is out of the preset position range, for example, when the pressure in the system decreases due to gas leakage or the like and the bellows 24 contracts abnormally, an alarm is issued. Can be. In the case of completely closed anesthesia, it is also possible to automatically control the flow rate of fresh gas sent from the anesthesia machine main body 2 so that the measured value becomes a preset value.

(3) Manual Ventilation The anesthesia apparatus 1 switches between the automatic ventilation modes (1) and (2) and the manual ventilation mode using the bag 29 by switching between automatic / manual operation by the switching valve 28. It can be easily switched. FIG. 4 shows a state in which the switching valve 28 is switched to the manual ventilation mode, and manual ventilation is performed using the bag 29. The flow path 44 is connected to the flow path 45 by switching the switching valve 28 to the manual ventilation mode.
This allows the bag 29 to flow through the channels 44, 45, 39 and 3
7 and communicate with the inside of the chamber 26a. In the suction phase of the manual ventilation mode, when the bag 29 is pressurized and gas is sent into the chamber 26a, the bellows 24
Is pushed, and the gas in the bellows 24 is sent to the patient A through the inspiratory flow path 21, the inspiratory valve 27, and the patient flow path 23. On the other hand, in the expiration phase, when the compression of the bag 29 is stopped and the gas in the chamber 26a is caused to flow toward the bag 29 or the excess gas discharge flow path 6, the expiration from the patient A is transmitted to the expiration valve 30, the expiration flow path 22, the gas enters the carbon dioxide absorption canister 31 through the flow path 34, and is sent into the bellows 24 through the flow path 35 as regenerated expiration gas from which carbon dioxide has been removed. In the manual ventilation, fresh gas sent through the flow path 2a is sent into the bellows 24.
In this manual ventilation, if the discharge adjusting screw of the APL valve 42 is turned to the valve open side, excess driving gas when being sent into the chamber 26a can be exhausted through the APL valve 42.

In the anesthesia apparatus of the present invention, the bellows 24 in the bellows-containing chamber 26 is operated by the ventilator in the automatic ventilation mode using the ventilator 40, and by manually operating the bag 29 in the manual ventilation mode. By pressing the button, the anesthetic gas can be sent to the patient A. Therefore, even if the automatic ventilation mode / manual ventilation mode is switched, the anesthetic gas having the same component composition is sent to the patient A, and the automatic / manual switching is performed. Even if it goes, there is no change in the intake gas composition.

(4) Excessive Gas Discharge FIG. 5 shows a state in which excess gas is discharged when the amount of gas in the circulation circuit 4 increases and the pressure increases. In the expiration phase by the automatic ventilation using the ventilator 40, as described in (2) above, the expiration from the patient A passes through the patient flow path 23, the expiration valve 30, the expiration flow path 22, and the flow path 34 to generate carbon dioxide gas. The gas enters the absorption canister 31, where the carbon dioxide gas is absorbed and removed, and is sent as regenerated expiration gas containing no carbon dioxide gas through the flow path 35 into the bellows 24. Further, the fresh gas sent through the flow path 2a and the fresh gas stored in the bag 29 are combined with the regenerated breath through the flow path 36 and sent into the bellows 24. At this time, if the gas pressure in the circulation circuit 4 exceeds a certain pressure, the pop-off valve 33 opens, and the excess gas in the circulation circuit 4 is discharged from the excess gas discharge channel 6, that is, the channels 38, 39, 45, 46, 49,5
1, sent to the rejection device through the surplus gas discharge valve 41 and the flow path 52. Also, in manual ventilation, the exhaled air overflowing from the circulation circuit 4 pushes the pop-off valve 33 open, and
9, 47, the APL valve 42, the flow paths 48, 49, 51, the surplus gas discharge valve 41 and the flow path 52 are sent to the rejection device.

[0040]

As described above, the anesthetic apparatus of the present invention has the following excellent effects. By providing a bellows-containing chamber in the circulation circuit and visually observing the expansion and contraction state of the bellows or by detecting with a sensor, it is possible to monitor whether the gas amount in the circulation circuit is appropriate. Also, by providing a fresh gas on-off valve for guiding the fresh gas sent from the anesthesia body to the bag in the inspiratory phase by the ventilator, the fresh gas is added to the gas amount in the bellows in the inspiratory phase and sent to the patient. Thus, the problem that the correct inspiratory volume cannot be determined is solved, and the inspiratory volume of the patient can be accurately grasped even in low flow anesthesia. Further, a sensor for detecting the expansion and contraction state of the bellows 24 is provided in the bellows-containing chamber 26, and the position of the bellows is continuously detected by the sensor to accurately monitor whether the gas amount in the circulation circuit is appropriate. Then, it can be displayed on the screen or an alarm can be issued when a danger is predicted, so that the safety can be enhanced and the patient monitoring system can be easily automated. Further, in the case of completely closed anesthesia, it is possible to automatically control the flow rate of fresh gas sent from the anesthesia machine main body so that the measured value becomes a preset value. In addition, the anesthesia gas can be sent to the patient by pressing the bellows in the same manner by the ventilator in the case of the automatic ventilation mode and by the breathing bag in the case of the manual ventilation mode. No change in composition. In addition, since the easily circulated circulation circuit is separated from the drive circuit portion and has an easily detachable structure, only sterilization processing can be performed by removing only the circulation circuit when performing sterilization processing to prevent propagation of bacteria in the circulation circuit. Therefore, labor and time for the sterilization can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an entire anesthesia apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an anesthesia circulation circuit for explaining an inspiratory phase by automatic ventilation in the same anesthesia apparatus. In the figure,
Among the flow paths, a solid line indicates a flow path in which a gas related to ventilation flows, and a broken line indicates a flow path in which a gas related to ventilation does not flow.

FIG. 3 is a block diagram of an anesthesia circuit for explaining an expiratory phase by automatic ventilation.

FIG. 4 is a configuration diagram of an anesthesia circuit for explaining a manual ventilation mode.

FIG. 5 is a configuration diagram of an anesthesia circuit for explaining the operation of the surplus gas discharge channel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anesthesia apparatus 2 Anesthesia machine main body 3 Anesthesia circulation circuit 4 Circulation circuit 5 Drive circuit part 6 Excess gas discharge flow path 21 Intake flow path 22 Expiration flow path 23 Patient flow path 24 Bellows 25 Fresh gas on-off valve 26 Bellows containing chamber 26a chamber 27 Intake valve 28 Switching valve 29 Bag 30 Expiration valve 31 Carbon dioxide absorption canister 32 Sensor 33 Pop-off valve 40 Ventilator 41 Excess gas discharge valve 42 APL valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toyogi Kugimiya 1-26-23 Kitamagome, Ota-ku, Tokyo (72) Inventor Shoichi Tsukagoshi 3-23-13 Hongo, Bungo-ku, Tokyo Izumi Kogyo Kagaku Kogyo Co., Ltd. Inside

Claims (6)

[Claims] 1. An anesthesia machine main body which mixes at least a laughing gas, an oxygen gas and a volatile anesthetic and supplies it as fresh gas, and supplies a fresh gas supplied from the anesthesia machine main body and a carbon dioxide gas from a patient's exhalation. An anesthesia circulation circuit which mixes the circulation air with the fresh gas and sends it to the patient as inspired air. In an anesthesia apparatus for anesthetizing a patient, the anesthesia circulation circuit includes: a chamber containing a bellows; A circulation circuit having an exhalation flow path connected to the flow path and configured to pass the exhalation of the patient through the carbon dioxide absorption canister through an exhalation valve and to send the exhalation flow into the bellows; A ventilator and bag to supply,
A switching valve for switching the connection between each of the ventilator and the bag and the inside of the chamber, and a flow path for sending fresh gas from the anesthesia device body into the bellows; A drive circuit unit connected to the bag and for introducing a fresh gas into the bag during the inspiratory phase of the ventilator. And a surplus gas discharge valve for discharging surplus gas is provided to the ventilator, and one end is connected to a flow path connecting the exhalation valve and the carbon dioxide absorption canister, and a pop-off valve which opens by surplus gas pressure is provided. 2. The anesthesia apparatus according to claim 1, further comprising an excess gas discharge passage connected to the other end of the excess gas discharge valve via an APL valve. 3. The anesthesia apparatus according to claim 1, wherein a sensor for detecting an upper end position or a projected area of the bellows is provided in the bellows-containing chamber. 4. Receiving a signal from the sensor, monitors whether the gas amount in the circulation circuit is appropriate, displays it on a screen, and issues an alarm when a measured value deviates from a preset value. The anesthesia apparatus according to claim 3, further comprising a monitoring device configured as described above. 5. A structure in which a connector is arranged in a flow path connecting the drive circuit unit and the circulation circuit, and the circulation circuit is detachable from the drive circuit unit.
An anesthetic apparatus according to claim 1. 6. The anesthesia apparatus according to claim 1, wherein the bellows-containing chamber has a structure in which the bellows can be taken out of the chamber.