JPH044762Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an inlet gas adjustment device that controls the flow rate and mixing ratio of inlet gas in an anesthesia device and can also be used as an artificial respiration device.

[Conventional technology]

Conventionally, anesthesia devices with various configurations have been put into practical use. An example is shown in FIG. In the figure, reference numerals 101a and 101b are inlets for introduction gases such as oxygen (O ₂ ) gas and laughing gas (N ₂ O), and each introduction gas supplied from the inlets 101a and 101b is passed through needle valves 102a and 102, respectively.
The flow rate is adjusted at b, and the flow meter (rotameter)
After passing through 103a and 103b, they are mixed and sent to an anesthesia vaporizer 104.

From the anesthesia vaporizer 104, the concentration adjustment dial 1
The anesthetic gas with the concentration set in 04a is derived,
This anesthetic gas is supplied to the patient circulation circuit 105,
It is configured to be inhaled by the patient through the patient supply port 106. Note that 107 is a safety valve provided in the patient circulation circuit for discharging excess gas, etc., 108 is a breathing bag, and 109 is a carbon dioxide absorption section.

By the way, in conventional anesthesia devices like this,
To set the flow rate of each introduced gas such as O ₂ gas and N ₂ O gas, the doctor first sets the total flow rate of the introduced gas and the mixing ratio of each introduced gas based on the patient's weight, gender, etc. The flow rate of each introduced gas is calculated based on the mixture ratio, and the needle valves 102a and 102a are manually operated while monitoring the flowmeters 103a and 103b.
102b to set the flow rate of each introduced gas to the calculated value.

Therefore, not only is it complicated to set and adjust the flow rate of each introduced gas, but also changes in the output pressure of the patient circulation circuit on the output side may cause errors in the flow meter display, making it difficult to obtain accurate flow rates and mixing. There were problems such as difficulty in supplying a ratio of the introduced gas flow.

To solve these problems, conventional O ₂
means for setting the total flow rate of introduced gas consisting of gas and N ₂ O gas, means for setting the mixing ratio of O ₂ gas or N ₂ O gas, and outputs of the introduced gas total flow rate setting means and the mixing ratio setting means. means for respectively setting the O ₂ gas flow rate and the N ₂ O gas flow rate based on the
a mass flow meter connected to an O ₂ gas source and an N ₂ O gas source, respectively; and a mass flow meter connected to the O ₂ gas source via the mass flow meter, the O ₂ gas flow rate setting means and the output of the mass flow meter. controlled based on signals
An O ₂ gas solenoid valve and an N ₂ O gas source connected to the N 2 O gas source via the mass flow meter and controlled based on the output signal of the N ₂ O gas flow rate setting means and the mass flow meter _. An introduction gas adjustment device configured with a gas solenoid valve has been proposed.

Next, the configuration of the introduced gas adjusting device will be explained based on FIG. 1. 1 is a setting section that sets the total flow rate (/min) of the introduced gas, which consists of a power supply and potentiometer, etc., and 2 is a setting section that sets the total flow rate (/min) of the introduced gas with a similar configuration.
This is an O ₂ gas mixture ratio setting section that sets the O ₂ gas mixture ratio (%), and the output side of each setting section 1 and 2 is used to display each set value set by the setting section 1 and 2. Display devices 3 and 4 are provided, respectively.
Setting outputs from each of the setting sections 1 and 2 are input to a multiplier 5, and the O ₂ gas flow rate is calculated. Further, the set output of the introduced gas total flow rate setting section 1 and the output of the multiplier 5 are input to a subtracter 6, and the flow rate of N ₂ O gas is calculated.

7 is a thermal mass flowmeter, which has a large number of main divided flow paths 7a.
and a flow rate detection branch channel 7b, a heating coil 8 is wound around the branch channel 7b, and a heating coil 8 is wound around the branch channel 7b.
The flow rate detection signal is obtained from the midpoint of . That is, the gas introduced into the branch flow path 7b passes through the heating coil 8 while being heated. This causes a temperature difference between the inflow end and the outflow end of the branch channel 7b, and thereby the potential at the midpoint of the heating coil 8 varies depending on the flow rate in the branch channel 7b. Therefore, the flow rate can be detected based on the potential fluctuation.

The thermal mass flowmeter 7 having such a configuration is connected to an O ₂ gas supply path connected to an O ₂ gas source 9, and a solenoid valve 10 is connected to the outflow side of the O 2 gas supply path. The detection output of the flow meter 7 is input to a flow rate indicator 11 to display the flow rate, and is also input to a comparator 12 to be compared with the O ₂ gas flow rate reference value calculated by the multiplier 5. It's summery. The solenoid valve 10 is controlled by the output of the comparator 12.

Similarly, an electromagnetic valve 17 is connected to the N ₂ O gas source 15 via a thermal mass flowmeter 16 having a similar configuration, and the electromagnetic valve 17 receives the detected output of the flowmeter 16 and the subtractor 6. It is designed to be controlled by the output of a comparator 18 into which the N ₂ O gas flow reference value is input. Further, the detection output of the flowmeter 16 is similarly input to a flow rate display 19, which displays the N ₂ O gas flow rate. The output sides of both the solenoid valves 10 and 17 are connected, and O ₂ gas and N ₂
The O gas is configured to be mixed and supplied to the anesthesia vaporizer side. Note that 21 and 22 are needle valves for power outage that are connected in parallel to the electromagnetic valves 10 and 17, respectively.

Next, the operation of the introduced gas adjusting device configured as described above will be explained. First, based on the patient's weight, gender, etc., set the predetermined total flow rate of introduced gas (/min) and O ₂ gas mixture ratio (%) using the total flow rate of introduced gas setting section 1 and 4 while observing each display 3 and 4. Set by operating the O ₂ gas mixture ratio setting section 2. Once the total flow rate of the introduced gas and the O ₂ gas mixing ratio are set, the multiplier 5 calculates the O ₂ gas flow rate, and the subtractor 6 calculates the N ₂ O gas flow rate.

Next, each of the calculated introduced gas flow rate reference values and the detected output signals from each thermal mass flowmeter 7 and 16 of each introduced gas flow supplied from each gas source 9 and 15 are sent to comparators 12 and 18, respectively. is entered,
The flow rate of each introduced gas stream is compared to a calculated reference value.
Then, the O ₂ gas solenoid valve 10 and the N ₂ O gas solenoid valve 17 are respectively controlled by the outputs of the comparators 12 and 18, and each introduced gas flow is controlled to a predetermined flow rate and mixed. It is fed towards the vaporizer.

As described above, each introduced gas flow rate is automatically calculated by simply setting and inputting the total flow rate of introduced gas and the mixing ratio using each setting section 1, 2, and the detection signal of each flow meter 7, 16 is used as the calculation standard. The flow rate of each introduced gas is accurately controlled and supplied to a predetermined value by controlling each electromagnetic valve 10, 17 accordingly. In addition, the thermal mass flowmeters 7, 16 and the solenoid valve 10,
Since the flow rate of each introduced gas is controlled by the flow rate control mechanism that combines 17 and 17, errors in each gas flow rate due to changes in gas pressure on the input and output sides can be avoided, as in an introduced gas adjustment device using a rotameter and a needle valve. are now being effectively prevented.

[The problem that the idea aims to solve]

The previously proposed induction gas regulator for anesthesia is capable of supplying a precisely controlled induction gas flow. By the way, when performing anesthesia surgery using such an anesthesia induction gas adjustment device, if the patient stops spontaneous breathing during the surgery, it becomes necessary to administer artificial respiration to the patient. Conventionally, when administering such artificial respiration, artificial respiration was performed by manually or mechanically intermittently pressing the breathing bag provided in the patient circulation circuit of the anesthesia machine shown in Figure 3. I was doing it.

However, when performing artificial respiration by pressing the breathing bag manually, it not only requires considerable effort, but also has problems such as inaccurate pressing cycles; However, there were problems in that the device was not only large-sized, but also had a complicated mechanism.

This invention was devised to solve the above-mentioned problems with conventional induction gas adjustment devices for anesthesia, and allows for the supply of accurately controlled induction gas, as well as accurate artificial respiration with a simple mechanism. An object of the present invention is to provide an anesthesia induction gas adjustment device that can be used also as an artificial respiration device.

[Means and actions to solve the problem]

In order to solve the above problems, the present invention provides means for setting the total flow rate of introduced gas consisting of O ₂ gas and N ₂ O gas, means for setting the mixing ratio of O ₂ gas or N ₂ O gas, and O 2 gas or N 2 O gas. ₂ gas or N ₂ O gas; and means for setting the O ₂ gas flow rate and the N ₂ O gas flow rate based on the outputs of the introduced gas total flow rate setting means and the mixture ratio setting means, respectively;
a dual flow meter connected to an O ₂ gas source and an N ₂ O gas source, respectively; and a dual flow meter connected to the O ₂ gas source via the mass flow meter, the O ₂ gas flow rate setting means and the mass flow meter controlled based on output signal
An O ₂ gas solenoid valve and an N ₂ O gas source connected to the N 2 O gas source via the mass flow meter and controlled based on the output signal of the N ₂ O gas flow rate setting means and the mass flow meter _. In an anesthesia induction gas adjustment device equipped with a gas solenoid valve, a switch element connected to ground is provided on the output side of the introduction gas total flow rate setting means, and the switch element is turned on and off at a predetermined period to perform intermittent control. It is configured so that it can be used as an artificial respiration device by supplying introductory gas.

In the induction gas adjustment device for anesthesia configured in this way, the flow rate of each introduction gas is automatically calculated by simply inputting and setting the total flow rate of the introduction gas and the mixing ratio. In addition to being able to supply a flow of introduced gas accurately controlled by the flow rate control mechanism, by turning on and off at a predetermined period a switch element connected to the ground provided on the output side of the total flow rate setting means for introduced gas. It can also be used as an artificial respiration device by intermittently supplying gas.

〔Example〕

Next, an example will be described. FIG. 2 is a block configuration diagram showing an embodiment of an anesthesia induction gas adjustment device that also serves as an artificial respiration device according to the present invention. are given the same reference numerals and their explanations will be omitted. In the present invention, in the induction gas adjustment device for anesthesia configured as shown in FIG. It is possible to intermittently supply introductory gas etc. by turning it on and off, etc., so that the introductory gas adjustment device for anesthesia can also be used as an artificial respiration device.

Furthermore, by configuring the switch element 23 and the introduction gas total flow rate setting section 1 to be controlled by the CO ₂ concentration at the end of expiration, etc., it can be used as a more suitable artificial respiration device. In other words, as shown in FIG.
is configured to be turned on and off by a drive device 24. Further, the introduced gas total flow rate setting section 1 is provided with an introduced gas total flow rate set value adjusting device 25 for adjusting the set value, and the setting value of the total flow rate setting section 1 is configured to be adjusted by the adjusting device 25. . The switch element driving device 24 and the introduced gas total flow rate setting value adjusting device 25 control the end-expiration phase at the patient supply port 106 of the patient circulation circuit 105.
It is configured to be controlled based on a detection signal from a detector 26 that detects the CO ₂ concentration or a detector 27 that detects the CO ₂ concentration of the patient's arterial blood flow.

With this configuration, the CO ₂ concentration at the patient's end of expiration or the CO ₂ concentration in the arterial blood flow is detected by the detector 26 or 27, and the detection signal is used to control the total flow rate setting value adjustment device 25 and the switch element. The drive 24 is controlled. This increases the patient's end-expiratory CO ₂ concentration or arterial blood flow.
Depending on the CO ₂ concentration, the on/off period and on/off ratio of the switch element 23 are adjusted, and the total flow rate of the introduced gas is adjusted. Therefore, it is possible to intermittently supply an optimal gas flow depending on the patient's condition and function as an accurate artificial respiration device.

[Effect of idea]

As explained above based on the embodiments, according to the present invention, the flow rate of each introduced gas is automatically calculated by simply inputting and setting the total flow rate of introduced gases and the mixing ratio, and the flow rate of each introduced gas is automatically calculated. It is possible to supply an accurately controlled inlet gas flow by a flow rate control mechanism that combines the Since it is configured to turn on and off, it can be used as an accurate artificial respiration device by intermittently supplying gas to be introduced using a simple mechanism.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing an example of the configuration of a conventionally proposed inlet gas adjustment device, and FIG. 2 is a block configuration diagram showing an embodiment of an inlet gas adjustment device that also serves as an artificial respiration device according to the present invention. , FIG. 3 is a schematic block diagram showing an example of a conventional anesthesia device. In the figure, 1 is the total flow rate setting section for introduced gas, and 2 is
O ₂ gas mixture ratio setting section, 3 and 4 are indicators, 5 is a multiplier, 6 is a subtracter, 7 and 16 are thermal mass flow meters,
9 is an O ₂ gas source, 10, 17 is a solenoid valve, 11, 1
9 is a flow rate indicator, 12 and 18 are comparators, 15 is a
N ₂ O gas source, 21 and 22 are needle valves for power outage, 23 is a switch element, 24 is a drive device, 25
26 and 27 are the total flow rate setting value adjustment device for introduced gas.
A CO ₂ concentration detector is shown.

Claims (1)

[Claims for Utility Model Registration] 1. Means for setting the total flow rate of the introduced gas consisting of O ₂ gas and N ₂ O gas, means for setting the mixing ratio of O ₂ gas or N ₂ O gas, and means for setting the total flow rate of the introduced gas consisting of O 2 gas and N 2 O gas, Based on the output of the flow rate setting means and the mixing ratio setting means
means for setting the O ₂ gas flow rate and the N ₂ O gas flow rate, a mass flow meter connected to the O ₂ gas source and _{the N 2 O} gas source, respectively; connected and said O ₂
a gas flow rate setting means; an O ₂ gas solenoid valve controlled based on the output signal of the mass flow meter; and a solenoid valve for O 2 gas connected to the N ₂ O gas source via the mass flow meter, and configured to set the N ₂ O gas flow rate. means and N ₂ O controlled based on the output signal of the mass flow meter.
In an induction gas adjustment device for anesthesia equipped with a gas electromagnetic valve, a switch element connected to earth is provided on the output side of the introduction gas total flow rate setting means,
1. An anesthesia induction gas adjustment device which can also be used as an artificial respirator by turning the switch element on and off at predetermined intervals to intermittently supply introductory gas. 2 comprising means for driving the switch element and means for adjusting the set value by the introduced gas total flow rate setting means, wherein the switch element driving means and the introduced gas total flow rate setting value adjusting means are configured to adjust the set value at the end of expiration or arterial blood flow. 2. The anesthesia induction gas adjustment device which can also be used as an artificial respirator according to claim 1, wherein the control is performed based on the CO ₂ concentration.