JPH0131233Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an artificial respiration device for supplying fresh breathing gas into a patient's respiratory system.
In particular, the present invention relates to a high-frequency artificial respiration device that generates high-frequency vibrations in breathing gas by a piston that is reciprocated at high frequency.

(Prior Art) Artificial respiration is administered to patients with respiratory system disorders. In this case, if the breathing gas supplied into the respiratory system is vibrated at a frequency significantly higher than the normal breathing rate, the oxygen and carbon dioxide exchange function of the lungs can be enhanced without increasing the internal pressure of the lungs. It is known that.

Therefore, various high-frequency artificial respiration apparatuses have been proposed in which breathing gas is vibrated at high frequency.

FIG. 4 shows an example of such a conventional high-frequency artificial respiration device.

As shown in this figure, a main conduit 1 of the artificial respirator is connected to a cylinder 2 at one end. A piston 3 provided within this cylinder 2
is designed to be reciprocated by a linear motor 4 at a high frequency of 4 to 30 Hz. The other end of the main conduit 1 is connected to a low pass filter 5.
This low-pass filter 5 has a labyrinth-like passage 5a, and an end portion of the passage 5a is connected to an exhaust port 5b.
It is open to the outside air by means of a pipe, and exhibits great resistance to high-speed flows, but is designed to allow slow-moving flows to pass through smoothly.

Further, a gas supply pipe 6 is connected to the middle part of the main pipe 1, and after fresh breathing gas sent from a breathing gas source (not shown) is humidified by a humidifier 7, The main pipe line 1 is passed through the gas supply pipe 6.
It is now supplied internally. The supply rate is usually about 5 to 7 per minute.

A ventilator nozzle 8 is provided within the low-pass filter 5 for ejecting breathing gas supplied from the same breathing gas source. This bench lily nozzle 8 jets gas in the opposite direction to the gas flowing out from the main pipe line 1, so that the pressure inside the main pipe line 1 is higher than atmospheric pressure. On the other hand, the main conduit 1 is provided with a valve 9 that opens when the internal pressure becomes higher than a predetermined value. The pressure within the main pipe 1 is monitored by a pressure monitor 10, and the amount of breathing gas ejected from the ventilator nozzle 8 is controlled according to the pressure. In this way, main pipe 1
The internal pressure is maintained within an appropriate range, slightly higher than atmospheric pressure.

Furthermore, a connector 11 is provided in the middle of the main conduit 1. This connector 11 is connected to the main pipe 1
The tube connecting tube 12 is connected to an endotracheal tube 14 inserted into a patient's respiratory system, such as a trachea 13.

In the artificial respiration apparatus configured in this way, fresh breathing gas is continuously supplied into the main pipe 1 and is discharged through the low-pass filter 5. That is, the inside of the main conduit 1 is always kept filled with breathing gas. Therefore, when the piston 3 is driven to reciprocate at a high frequency, the breathing gas within the main pipe 1 will vibrate at a high frequency. Since the vibration is blocked by the low-pass filter 5,
It will not be released to the outside.

When high-frequency vibrations occur in the main conduit 1 in this manner, the vibrations are transmitted to the patient's lungs 15 through the endotracheal tube 14 and the patient's trachea 13. Therefore, the gas in the lungs 15 vibrates at a high frequency, promoting the diffusion of the gas and allowing the oxygen/carbon dioxide gas exchange function of the lungs 15 to work well.

When the patient breathes spontaneously, the exhaled air is discharged to the outside through the low-pass filter 5. In that case,
Since the flow of exhaled air is slow, it is not resisted by the low-pass filter 5.

Conventionally, in such a high-frequency artificial respiration device, the piston 3 within the cylinder 2 was in sliding contact with the inner surface of the cylinder 2 via a piston ring 3a, similar to a normal cylinder unit.

(Problems to be Solved by the Invention) By the way, such an artificial respirator is operated continuously for an average of one week for one treatment, and for a long period of one month or more in some cases. Therefore, durability is particularly required for artificial respiration devices.

However, in a conventional high-frequency artificial respiration device in which the space between the cylinder 2 and the piston 3 is sealed by a piston ring 3a, the piston 3 is driven back and forth at a high frequency.
It is inevitable that the inner surface of the cylinder 2 and the piston ring 3a will wear out. Therefore, it is difficult to increase durability. Furthermore, when such wear occurs, there is a risk that the wear particles may mix with the breathing gas in the main conduit 1 and enter the patient's lungs 15.

Further, in such a device, heat is generated due to friction between the cylinder 2 and the piston ring 3a, so a cooling mechanism for the cylinder 2 and the piston 3 is required. Therefore, its structure has become complicated.

It would be good if the inner surface of the cylinder 2 could be lubricated, but since breathing gas is introduced into the cylinder 2 and communicated with the patient's lungs 15, no lubricant can be used.

The present invention was devised in view of these problems, and its purpose is to provide a high-frequency artificial respiration device that has a simple structure and is highly durable.

(Means for Solving the Problem) In order to achieve this purpose, the present invention provides a piston ring for a piston that generates high-frequency vibrations in the main pipe of a high-frequency artificial respiration device. I try to use something smaller to some extent. A gas supply pipe for supplying breathing gas into the main pipe is connected to a tube connecting pipe to which the endotracheal tube is connected.

(Function) With this configuration, a gap is formed between the inner surface of the cylinder and the piston ring, so that they are prevented from wearing out. Moreover, the reciprocating movement of the piston allows the breathing gas in the main pipe to be vibrated at high frequency.

Providing such a gap will cause gas to leak from between the cylinder and the piston, but since the gas supply pipe is connected to the tube connection pipe close to the patient's mouth, it is difficult for the patient to breathe. Sufficient gas supply will be ensured.

(Example) Hereinafter, an example of the present invention will be described using the drawings.

In the figure, FIG. 1 is a system diagram showing one embodiment of the high-frequency artificial respiration apparatus according to the present invention. In this embodiment, the basic structure is the same as that of the conventional one shown in FIG. 4, so corresponding parts are given the same reference numerals and detailed explanation thereof will be omitted.

As is clear from FIG. 1, the piston ring 3a of the piston 3 that is reciprocated within the cylinder 2
The outer diameter of the cylinder 2 is smaller than the inner diameter of the cylinder 2. Therefore, a gap r is formed between the piston ring 3a and the inner surface of the cylinder 2. The size of the gap r is approximately 0.05 to 0.15 mm.

Further, a gas supply pipe 6 that supplies breathing gas to the main pipe line 1 is connected to a tube connecting pipe 12 that branches from the main pipe line 1 .

The rest of the configuration is the same as that in FIG. 4.

In the high-frequency artificial respiration apparatus configured in this way, fresh breathing gas is supplied from the breathing gas source at a rate of about 5 to 7 times per minute, and the humidifier 7
After being humidified by the gas, the gas is introduced to the tube connecting pipe 12 through the gas supply pipe 6. The gas is introduced into the lungs 15 through the endotracheal tube 14 and the patient's trachea 13, fills the main conduit 1 and cylinder 2, and is discharged to the outside through the low-pass filter 5.

Therefore, when the piston 3 is reciprocated frequently by the motor 4, the gas in the cylinder 2 expands and contracts, causing frequent vibrations in the gas in the main pipe 1. The vibrations are then transmitted into the patient's lungs 15.

At this time, there is a gap r between the inner surface of the cylinder 2 and the piston ring 3a of the piston 3, and gas leaks through the gap r, but since the gap r is relatively small, it is ensured that the gas is not contained in the main pipe 1. can generate vibrations. If the gap r is about 0.05 to 0.15 mm, the amount of leakage will be 2 times per minute even under a pressure of 15 cm of water column.
can be kept within. Main pipe 1 has 5~1 min.
Since fresh gas of about 70% is constantly supplied, and the main pipe 1 is originally open to the outside air via the low-pass filter 5, it would normally be a practical problem even if that much gas leaks. Never.

By the way, when the artificial respirator is removed from the patient, the amount of breathing gas supplied from the breathing gas source is gradually reduced. At that time, the gas supply pipe 6
If the cylinder 2 is connected close to the cylinder 2, the supplied fresh gas will flow out from the cylinder 2 side, resulting in an insufficient amount of gas sent to the patient. However, in the present invention, the gas supply pipe 6 is connected to the tube connection pipe 12 close to the patient's mouth, so even in such a case, a sufficient amount of fresh gas is ensured to be supplied to the patient. Ru.

In this way, the artificial respiration device can be operated reliably even without the piston ring 3a of the piston 3 coming into contact with the inner surface of the cylinder 2. Therefore, the inner surface of the cylinder 2 and the piston ring 3a
can prevent wear and increase its durability. Furthermore, since no frictional heat is generated between the piston ring 3a and the inner surface of the cylinder 2, a cooling mechanism for the piston ring 3a and the inner surface of the cylinder 2 is not required, and the cylinder 2
Also, the structure of the piston 3 can be simplified. Furthermore, the power required for the motor 4 is also reduced, and a small motor can be used, so the entire device can be made compact.

FIG. 2 is a system diagram showing another embodiment of the artificial respirator according to the present invention.

In this embodiment, another tube 16 is connected to the tube connecting tube 12 of the connector 11, and another tube connecting tube 17 is connected to the tip of the tube 16.
is installed. The endotracheal tube 14 is connected to the tube connecting tube 17. That is, the main pipe 1 is connected by these tube connecting pipes 12, 17 and tube 16
A long tube connecting pipe is formed branching from the pipe. The gas supply pipe 6 is connected to a tube connecting pipe 17 on its distal end side. Therefore, the distance between the branching part from the main pipe line 1 and the connecting part of the gas supply pipe 6 is made sufficiently long.

Since the other configurations are the same as those of the embodiment shown in FIG. 1, corresponding parts are given the same reference numerals and their explanation will be omitted.

In the artificial respiration apparatus configured in this way, the connection part of the gas supply pipe 6 is sufficiently far from the branch part of the main pipe line 1, so that fresh breathing gas supplied from the gas supply pipe 6 is routed through the main pipe line. Outflow through 1 is further suppressed. That is, the efficiency of supplying fresh gas to the lungs 15 is increased, and the amount of fresh gas supplied from the breathing gas source can be reduced.

The length of the tube connecting pipe from the branching part of the main pipeline 1 to the connecting part of the gas supply pipe 6 may be about 3 to 20 cm. If the length is too long, vibrations within the main conduit 1 will not be sufficiently transmitted to the lungs 15.

The present inventors connected a simulated lung to such an artificial respirator and conducted an experiment to confirm the gas supply effect. In the experiment, pure oxygen gas was supplied from the gas supply pipe 6 at a flow rate of 1 per minute, and the oxygen concentration in the simulated lungs was measured over time. At that time, the pressure inside main pipe 1 was 15 cm of water column.
Cylinder 2 was set so that 4 leaks occurred per minute.

Under these same conditions, the gas supply pipe 6
() Corresponding to the embodiment shown in Fig. 2, connected at a position 15 cm away from the branch of main pipe 1, ()
(1) Connector 11 connected to tube connection pipe 12 corresponding to the embodiment shown in FIG. I conducted an experiment.

FIG. 3 is a graph showing the experimental results.

As is clear from this figure, in a conventional example () in which the gas supply pipe 6 is directly connected to the main pipe 1, if a large amount of gas leaks from the cylinder 2, a considerable amount of fresh gas will be released from the gas supply pipe 6. Unless the lungs are supplied with fresh gas, the lungs cannot be adequately supplied with fresh gas. On the other hand, when the gas supply pipe 6 is connected to a tube connecting pipe that branches off from the main pipe 1, even if the length of the tube connecting pipe is short as shown in parentheses, fresh gas in the lungs is The concentration can be sufficiently increased. It can be seen that if the length of the tube connection tube is made sufficiently long as shown in (), the concentration of fresh gas in the lungs can be further increased in a shorter time.

In this way, the gas supply pipe 6 is connected to the tube connecting pipe for connecting the endotracheal tube 14 that branches from the main pipe line 1.
If a relatively large amount of gas leaks from the cylinder 2 by making the length between the branch from the main pipe 1 and the connection of the gas supply pipe 6 sufficiently long, It also becomes possible to introduce fresh breathing gas supplied from the gas supply pipe 6 into the lungs 15.

In the above embodiment, the low-pass filter 5 has a labyrinth-like passage 5a, but the low-pass filter 5 may also be one in which an elongated tube is wound in a spiral shape, or one in which breathing gas is passed in the opposite direction. It is also possible to use a chamber type device that prevents the emission of high-frequency vibrations by ejecting the vibrations.

(Effects of the invention) As is clear from the above explanation, according to the invention, the piston ring of the piston that generates high-frequency vibrations in the gas in the main pipe has an outer diameter smaller than the inner diameter of the cylinder. Since the ring does not come into sliding contact with the inner surface of the cylinder, it is possible to prevent these from being worn out and to provide high durability. Furthermore, since the gap therebetween may be small, it is possible to reliably cause high-frequency vibrations in the gas within the main pipe.

Furthermore, since the piston ring and the inner surface of the cylinder do not come into sliding contact, no frictional heat is generated between them. Therefore, the cooling mechanism becomes unnecessary, and the structure can be simplified. Furthermore, since there is no friction between the piston ring and the inner surface of the cylinder, the required horsepower of a linear motor or the like for driving the piston can be reduced, and the entire device can be made inexpensive.

Then, the gas supply pipe that supplies breathing gas,
The tube is connected to the endotracheal tube connection tube close to the patient's mouth, so even if gas leaks from between the piston and cylinder, the patient is reliably supplied with fresh breathing gas. be able to.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the high-frequency artificial respiration device according to the present invention, FIG. 2 is a system diagram showing another embodiment of the high-frequency artificial respiration device according to the present invention, and FIG. FIG. 4, which is a graph of the results of an experiment conducted to confirm the effectiveness of the high-frequency artificial respiration device according to the present invention, is a system diagram showing an example of a conventional high-frequency artificial respiration device. DESCRIPTION OF SYMBOLS 1... Main pipe line, 2... Cylinder, 3... Piston, 3a... Piston ring, 4... Linear motor, 5... Low pass filter, 6... Gas supply pipe, 12... Tube connection pipe, 14... ...Intratracheal tube, 16...Tube, 17...Tube connecting tube.

Claims (1)

[Claims for Utility Model Registration] (1) A main pipe whose one end is connected to a cylinder having a piston that is driven reciprocally at high frequency, and whose other end is open to the outside air through a low-pass filter; A high-frequency artificial respiration device comprising: a gas supply pipe that supplies breathing gas; and a tube connecting pipe that branches from the main pipe and is connected to an endotracheal tube that is inserted into a patient's respiratory system; The outer diameter of the piston ring of the piston is smaller than the inner diameter of the cylinder to the extent that a predetermined amount of clearance is formed between the piston ring and the inner surface of the cylinder, and the gas supply pipe is connected to the tube connection pipe. A high-frequency artificial respiration device, characterized by: (2) The length between the branching part of the tube connecting pipe from the main pipe and the connecting part to which the gas supply pipe is connected is sufficiently long, as claimed in Claim No. 1 of Utility Model Registration. High-frequency artificial respiration equipment described in item ).