JPH0535151U - Anesthetic drug vaporizer - Google Patents

Abstract

(57) [Summary] [Purpose] In an animal anesthesia machine, a relatively low concentration and flow rate of anesthetic gas suitable for small animals such as rats and mice are used.
Supply easily and stably. [Structure] An anesthetic gas of a desired concentration is generated by directly injecting the anesthetic drug, which is a liquid, at a desired flow rate into the vaporizing portion of the anesthetic drug through which the compressed gas passes to vaporize everything.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inhalation anesthesia device for animals, and more particularly to an anesthesia drug vaporization device for generating anesthesia gas for anesthesia of so-called small animals such as rats and mice.

[0002]

[Prior Art]

 Categorizing animals based on their body shape and weight can be roughly divided into the following.

Large animals Cows and horses Medium animals Dogs and sheep Small animals Rats and mice

[0004] Of these, large animals have a relatively large respiratory ventilation, so anesthesia machines for large animals are suitable considering their characteristics, but for middle animals, human anesthesia machines are used. You can also do it.

It is also well known that the so-called small animals such as the rat and the mouse greatly contribute to the collection of academic materials in medicine.

[0006] In order to collect this data, there are many cases where these small animals are dissected or operated on. However, in order to securely fix the small animals and facilitate the operation, the small moving object that is a subject is operated. It is desirable to anesthetize.

Conventionally, for anesthesia of this small animal, an anesthesia machine for humans has been mainly used while reducing the concentration (volume ratio, the same applies hereinafter) and flow rate of the anesthetic gas supplied.

As a raw material of this anesthetic gas, non-combustible and non-explosive halogen (Japanese Pharmacopoeia name) is mainly used. An anesthesia machine for humans aerates a gas such as air or oxygen into an anesthetic drug heated to a desired temperature and vaporizes the anesthetic drug to obtain an anesthetic gas. The gas is diluted to obtain the desired concentration and flow rate. For example, an example thereof is disclosed in Japanese Patent Publication No. 2-53065.

[0009]

[Problems to be solved by the device]

 A comparison of the specifications of human anesthesia and small animal anesthesia is as follows. For humans (adults) For small animals Weight (kg) Approx. 50-65 Approx. 0.15-1.5 Concentration (%) 3-5 0.3-2 Flow rate (liter / min) 3-6 0.1-1 1 Treatment time per time (hours) 3 to 6 1 to 2

The above flow rate does not mean that all of the supplied anesthetic gas is delivered to the respiratory system as inhaled gas. In the case of large animals, middle animals and humans, anesthesia gas may be supplied by an inhalation mask at the time of induction of anesthesia and a tube inserted into the trachea at the time of surgery, and the concentration and flow rate may be adjusted appropriately. In the case of the small animals of this example, the concentration and flow rate of the anesthetic gas were constant both during the introduction of the sickness and during the treatment, and the anesthetic gas was supplied using a trap-shaped inhalation jig.

Therefore, when anesthesia for small animals is performed by reducing the concentration or flow rate of the human anesthesia machine, it may be impossible to stably supply the anesthetic gas having a desired concentration or flow rate. There was a problem.

[0012]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention provides a new anesthesia machine for the small animals described above, and has the following features in the structure for vaporizing an anesthetic drug.

There is no configuration for aerating gas directly into the liquid of the anesthetic drug. The anesthetic drug, which is a liquid, is directly injected into the vaporizing portion of the anesthetic drug through which the compressed gas passes at a desired flow rate to vaporize all of the anesthetic drug, thereby generating an anesthetic gas having a desired concentration.

The flow rate of injecting the anesthetic drug and the flow rate of the compressed gas need to be appropriately changed depending on the size of the small animal to be operated. For example, in the case of a mouse or a hamster, the anesthetic drug is injected. The flow rate is about 30 cc per hour, and the flow rate of the compression gas supplied to the vaporization section is about 0.1 to 0.3 liter / minute.

[0015]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings, but the present invention is not limited to this embodiment.

FIG. 1 is a flow chart showing an embodiment of the present invention in which an electric system of an inhalation anesthesia drug vaporizer suitable for small animals is omitted. In this figure, reference numeral 10 is a suction filter in which 12 gas transfer devices serve as inlets for sucking gas. The gas pressurized by the gas transfer device is configured to be supplied to the vaporization section 16 via the flow rate controller 13, the flow meter 14 and the pipe 15.

Then, in the middle of the vaporization section 16, a drip regulator 18 is supplied from a container 20 containing the anesthetic agent to supply a drip-shaped anesthetic agent so that the anesthetic agent is completely vaporized in the vaporization section. The anesthetic gas is generated by the above, and the sickness gas is supplied to the small animal as the subject through the discharge port 24 through the pipe 22.

The flow meter 14 is of a flow sphere type having a maximum flow rate instruction value of 1.0 liter / min. Further, the dropping regulator 18 has a structure in which the anesthetic drug supplied in the form of a drip is temporarily stored and made into a substantially continuous flow.

In this embodiment, since the gas transfer unit 12 and the vaporization unit 16 are housed in the same housing, part of the heat generated by the gas transfer unit 12 when the power consumption is about 15 W is the flow rate. Although it is released together with the gas released through the regulator 13 to the outside of the system, the amount of heat that remains inside the system is about 30 cc per hour of vaporization heat (about 3,500 calories, about 4 It is the necessary and sufficient amount of heat to make up for the equivalent of watt hours.

With such a configuration, it is possible to reduce the temperature rise of the device due to the amount of heat generated in the housing of the gas transfer device 12 and the heat of vaporization of the anesthetic drug injected into the vaporization section 16. The gas temperature rises and the gas is completely vaporized. After passing through the vaporization section, the anesthetic gas is supplied to the animal after being cooled to about room temperature by a pipe of several meters.

Further, since the anesthetic drug and the anesthetic gas are highly corrosive, it is preferable to use a member having excellent corrosion resistance for the vaporizing section, the pipe and the like. In this embodiment, the pipe 22 and the pipe connecting the container 20 and the vaporization part 16 are made of tetrafluororesin (trade name Teflon), and the vaporization part 16 and the discharge port 24 are made of stainless steel. The container (including the lid) 20 was made of glass, and the dropping adjuster 18 was made of glass, tetrafluororesin and stainless steel.

The anesthesia machine for humans has a relatively high flow rate of anesthesia gas, and also in terms of safety, a part of the anesthesia gas is branched and the concentration is continuously measured and monitored during the operation. However, in the anesthesia machine for small animals of the present invention, the flow rate of anesthesia gas is relatively small, and it is not appropriate to branch the anesthesia gas to measure the concentration. The sickness gas was supplied directly to the densitometer and adjusted to a desired concentration before being used for anesthesia.

Since the gas from the suction filter 10 to the pipe 15 is a normal gas (air in this embodiment), the materials of these members do not have to be particular.

In the present embodiment, the vaporizing section 16 is about 1.5 m long, and a stainless steel pipe having an inner diameter of 5 mm and an outer diameter of 6 mm wound in a coil shape having an inner diameter of about 5 cm is attached almost vertically. Then, the pipe 15 was connected to the uppermost part of the vaporization section, the pipe 17 was connected to the position approximately ⅓ below the uppermost part, and the pipe 22 was connected to the lowermost part.

In this vaporizing section, the pressure of the compressed gas in the pipe 15 is made smaller than the pressure of the anesthetic drug in the container 20 and the pipe 19 to the drip regulator 18, and the pipe 17 is closed. By connecting to the middle of the vaporization section 16 (about 1/3 below the uppermost part in this embodiment), the pressure of the compressed gas does not hinder the dropping of the anesthetic drug, and the anesthetic drug is supplied to the pipe 15 There is an effect that all can be injected into the vaporizing part 16 without flowing back to the above.

In the configuration of the present embodiment, in practical use, all the anesthetic drug injected into the vaporizing section 16 is vaporized to be an anesthetic gas, but at the initial stage of operation when the device temperature has not yet risen and during concentration adjustment. In this case, since the remaining anesthetic drug may come out to the pipe 22 as a liquid without completely vaporizing the anesthetic drug, a liquid trap is attached to the outlet side of the vaporizing section 16. It is preferable that the liquid anesthetic drug is separated and collected.

The pressure of the anesthetic drug applied to the inlet of the drip regulator 18 is directly proportional to the height from the inlet to the liquid level of the anesthetic drug including the pipe 19. Therefore, when the position of the height of the liquid surface is lowered by consuming the anesthetic drug, the pressure of the anesthetic drug applied to the inlet also changes, and the drip flow rate changes.

In the present embodiment, since the height (length) of the pipe 19 is made sufficiently large with respect to the height (depth) of the anesthetic drug in the container 20, the dripping flow rate due to consumption of the anesthetic drug is The change, that is, the change in the concentration of the anesthetic gas was in a range that would not hinder practical use.

When it is necessary to further reduce the change in the concentration of the anesthetic gas due to the consumption of the anesthetic drug described above, or the height (length) of the pipe 19 needs to be further lowered (shortened). In some cases, it is equipped with a height adjuster that can move the position of the anesthetic drug container up and down, and it moves at a constant speed as the anesthetic drug is consumed by a synchronous motor, or a liquid level sensor and servomotor. It is desirable that the height of the liquid level of the anesthetic drug in the container be kept substantially constant by a height adjuster driven by the.

In the present embodiment, the compressed gas supplied to the pipe 15 is the air compressed by the gas transfer device 12, but this compressed gas is the compressed gas supplied from the outside of the apparatus. The compressed gas is not limited to air and may be oxygen or a mixed gas of oxygen and laughing gas.

In this embodiment, as a means for supplying the anesthetic drug to the vaporizing section 16 for vaporizing the anesthetic drug, a dripping regulator 18 is used to inject the anesthetic drug at a constant flow rate by a drip method of about once every 8 seconds. I entered,

As another method, a configuration may be adopted in which a desired constant flow rate of liquid (anesthetic drug) is continuously injected for a desired time. For example, a syringe controller or the like that allows injection at a constant rate by using a syringe-shaped container of anesthesia drug is used.

In the present embodiment, the vaporizing section 16 is formed by making a stainless steel pipe into a coil shape and attaching it substantially vertically. However, the shape of this pipe is not limited to the coil shape, and it may be a spiral shape or a linear shape. Even so, the effect remains the same.

Further, when the pipe has a coil shape, the pipe is attached substantially vertically. However, when the pipe has a spiral shape, the pipe may be vertically inclined.

When the supply of the compressed gas to the vaporization unit 16 is stopped in order to stop the generation of the anesthetic gas, the anesthetic drug is continuously dropped from the dripping adjuster 18, and the anesthetic gas is not compressed. Since the pressurization by the gas is also eliminated, the dropping period may be shortened.

Therefore, when the generation of anesthesia gas is stopped by attaching a corrosion-resistant solenoid valve or the like that is closed in the middle of the pipe 19 at the same time as the supply of the compressed gas is stopped, the supply of the anesthesia drug is stopped. It is necessary to make the structure so that the supply is also stopped.

Although the present invention has a configuration suitable for inhalation anesthesia of small animals, by changing the scale according to this configuration, an anesthetic drug vaporizer for medium animals, large animals, or humans can be constructed. It is also possible.

[0038]

[Effect of the device]

 By implementing the present invention, it is possible to easily and stably set a relatively low concentration and flow rate suitable for anesthesia of small animals.

[Submission date] February 29, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Problems to be solved by the device]

Table 1 below shows a comparison between the specifications of human anesthesia and small animal anesthesia.

Table 1 For humans (adults) For small animals Weight (kg) Approx. 50-65 Approx. 0.15-1.5 Concentration (%) 3-5 0.3-2 Flow rate (liter / min) 3-60. 1 to 1 Treatment time (hours) 3 to 6 1 to 2

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention in which an electric system of an inhalation anesthesia drug vaporizer suitable for small animals is omitted.

FIG. 2 is a vertical cross-sectional view for explaining details of the drip regulator.

[Explanation of symbols]

 10 Inhalation Filter 11 Flow Rate Control Gas Outlet 12 Gas Transfer Device 13 Flow Rate Controller 14 Flow Meter 15 Piping 16 Vaporizing Section 17 Piping 18 Dropping Regulator 19 Piping 20 Container 22 Piping 24 Discharge Port 30 Drip Part 32 Anesthesia Drug Reservoir 34 Flow Control screw

Claims (5)

[Scope of utility model registration request] 1. Generation of an anesthetic gas comprising a container for storing an anesthetic drug for inhalation, a drip regulator connected to the container, a vaporization section for vaporizing the anesthetic drug, and a gas transfer device for compressing and transferring the gas. In the device, the gas discharged from the gas transfer device is connected to the vaporizing section by a pipe, and the anesthetic drug whose flow rate is adjusted to a desired value by the dropping regulator is caused to flow down to the vaporizing unit, and the anesthetic drug is supplied. It is configured to be vaporized and mixed with the gas, and the vaporization section is arranged at a position that absorbs power of the gas transfer section and heat generated by compression of the gas, and this heat is used as heat of vaporization of the anesthetic drug. An anesthetic drug vaporizer characterized by being configured to be provided. 2. A height adjuster capable of vertically moving the position of a container for containing an anesthetic drug for inhalation is provided, and the liquid level of the anesthetic drug decreased by dropping is substantially adjusted by the height adjuster. 2. The anesthetic drug vaporizer according to claim 1, wherein the anesthetic drug vaporizer is configured to be maintained at a constant height. 3. The anesthetic drug vaporizer according to claim 1 or 2, wherein the means for compressing and transferring the gas is a compressed gas supplied from the outside. 4. A heat source of heat of vaporization for vaporizing an anesthetic drug,
4. The anesthetic drug vaporization device according to claim 1, wherein the temperature is the temperature of the ambient atmosphere or the heat from the heating means supplied from the outside. 5. The means for supplying the anesthetic drug to the vaporizing section for vaporizing the anesthetic drug has a configuration such that a liquid having a desired constant flow rate is continuously injected for a desired time. The anesthetic drug vaporization device according to claim 1, claim 2, claim 3, or claim 4.