JPH11197246A - Intermittently positive pressure type respiratory assisting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply decrease the rebreathing amount and enable inhalation of curative gas with the maximum density by providing a curative gas mix-in port in the midway of a conduit means. SOLUTION: A curative gas mix-in port 4 attached to a mask frame 5 is installed in a position spaced at a designated distance from a mask 6. For example, when the port is installed in such a position that the volume in a conduit from the mask 6 to the curative gas mix-in port 4 is about 560 cm<3> , mixed oxygen gas is stored in the conduit, and oxygen gas of about 40% at the maximum can be supplied to a user. Further, oxygen gas with the highest density can be inhaled when the inhalation quantity is maximum during the inhalation period. When this position is at a position of about 1200 cm<3> , about 40% oxygen gas can be inhalated at maximum, and when the volume in the conduit is too large, the highest density oxygen gas inhalation enable period is shifted from the necessary period. When the curative gas mix-in port 4 is thus positioned in the optimum midway, oxygen gas with the highest density can be inhaled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive pressure breathing assist device using a mask. More specifically, intermittent positive pressure ventilation therapy (IPPV: Interm
The present invention relates to an intermittent positive-pressure respiratory assist device used for ittent positive pressure ventilation (etc.).

[0002]

2. Description of the Related Art Intermittent Positive Pressure Ventilation Therapy (IPPV) suitable for the treatment of patients with ventilatory insufficiency such as hypercapnia
Various respiratory aids (artificial respirators), respiratory masks (nasal masks, mouth masks, nasal-mouth masks, etc.) and therapeutic gas mixing devices attached to them are used for, for example, for the negative pressure ventilation.

[0003] Of the devices generally used for mask-type intermittent positive pressure ventilation therapy, those using a nasal mask are shown in FIG.
Shown in The main body 1 generates a positive pressure gas of about 4 to 30 cmH ₂ O intermittently and sends it to the conduit 2. Above all, devices that supply two levels of positive pressure gas according to inhalation and expiration are the mainstream. The conduit 2 is connected to a mask frame 5 for fixing a nasal mask 6, and a positive pressure gas is supplied to the user 7 through the nasal mask 6.
To the nose.

The exhalation discharge hole 3 is provided for discharging the exhaled gas of the user 7, and the therapeutic gas mixing port 4 is provided for supplying the therapeutic gas when mixing of the therapeutic gas is required. Used by connecting to the device. In addition, most of the exhalation discharge hole 3 and the therapeutic gas mixing port 4 are attached to a mask frame 5 for fixing a mask.

[0005] Some of the intermittent positive pressure ventilation using such a mask require the incorporation of a therapeutic gas into the positive pressure gas.
Oxygen gas at a constant flow rate of 5 to 5 L / min is often mixed. However, in many of the conventional devices, since the therapeutic gas mixing port 4 is provided in the mask or in the vicinity of the exhalation discharge hole 3, during the exhalation period, the therapeutic gas is mixed with the exhaled gas and the positive pressure gas. It is easy to be discharged from the exhalation discharge hole 3 along with the flow, and a part of the mixed therapeutic gas is discharged without being inhaled by the user 7 and is wasted.

[0006] Further, it is difficult for such a device to completely exhaust the expiration of the user 7 to the outside of the mask, the mask frame 5 and the conduit.
Rebreathing ₂ can be a problem.

To reduce the amount of rebreathing, the area of the exhalation discharge hole 3 is increased so that the exhalation of the user 7 is easily exhaled, or, for example, as shown in FIG. There is a method of positioning the discharge hole 3 and the like.

[0008] However, in general, a mask that excels in exhalation, that is, a mask that has a smaller amount of CO ₂ rebreathing, tends to have a lower concentration of the therapeutic gas during inhalation. Some masks have the drawback of low respiratory volume but low therapeutic gas concentrations during inspiration.
Therefore, in a device in which the exhalation discharge hole 3 and the therapeutic gas mixing port 4 are attached to a mask or a mask frame 5, the rebreathing amount and the therapeutic gas concentration during inspiration are in a trade-off relationship, and they can be compatible. It was difficult.

For this reason, in order to obtain the concentration of the therapeutic gas required during inhalation, a method of changing to a mask having a small area of the exhalation discharge hole 3 or increasing the flow rate of the therapeutic gas has been adopted. However, the former has a problem of CO ₂ rebreathing amount, and the latter has a problem of waste of therapeutic gas.

Further, when a mask having a relatively large area of the exhalation discharge hole 3 is used, even if oxygen gas having a constant flow rate of a maximum flow rate of 5 L / min is mixed by a general oxygen concentrator, the user 7 Even if the therapeutic gas is mixed at the maximum flow rate of the existing therapeutic gas supply device, the necessary therapeutic gas concentration cannot be supplied to the user 7 so that the oxygen gas concentration required for the treatment of the patient may not be achieved. .

[0011] Further, there is a type in which a therapeutic gas mixing port 4 is provided at a connection portion between the respiratory aid main body 1 and the conduit 2.
However, in this method, since the volume in the conduit from the therapeutic gas mixing port 4 to the mask is fixed, depending on the respiratory flow pattern of the user 7, it may not be possible to obtain a high-concentration therapeutic gas during inspiration. is there.

In addition, a respiratory gas having a predetermined therapeutic gas concentration is blended in advance, and the respirator body 1 is
There is also a device that always supplies a constant concentration of the therapeutic gas to the user 7 by providing a device capable of supplying a blended respiratory gas at a position where air is sucked from the outside to send a positive pressure gas to the user 7. However, they are complex devices and are very expensive.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a method for intermittent positive pressure ventilation, which enables a user 7 who needs to mix therapeutic gas with a simple, low rebreathing volume and a constant flow rate.
It is an object of the present invention to provide an intermittent positive-pressure respiratory assist device that can inhale the highest concentration of a treatment gas when a certain concentration of the treatment gas is mixed.

[0014]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies and as a result, have found that a therapeutic gas mixing port for mixing a therapeutic gas into the conduit means for connecting the respirator body 1 and the mask. 4 and the volume in the conduit from the location of the gas entry port 4 to the respirator is
From about the time corresponding to the maximum value of the expiratory flow to about the time corresponding to the maximum value of the inspiratory flow, by providing an intermittent positive pressure type breathing assist device characterized by being substantially equal to the gas volume passing through the conduit 2. It has been found that the above problems can be solved.

That is, the present invention provides a breathing assist device 1 for supplying positive pressure air intermittently in response to a user's breathing, a respiratory mask for supplying the user with the positive pressure air, and the breathing device An intermittent positive-pressure respiratory assist device having a conduit means for connecting the auxiliary device 1 and the respiratory mask, characterized in that a therapeutic gas mixing port 4 for mixing a therapeutic gas is provided in the middle of the conduit means. An intermittent positive pressure breathing assist device is provided.

Further, according to the present invention, the volume in the conduit from the position of the gas mixing port 4 to the respiratory mask corresponds to the maximum value of the inspiratory flow from the time corresponding to the maximum value of the user's expiratory flow. The intermittent positive pressure type respiratory assist device is characterized in that the volume is 0.7 to 1.3 times, particularly 1 times the gas volume passing through the conduit 2 by the time.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Among the gases inhaled by a user 7,
What actually reaches the alveoli and performs gas exchange,
Only the gas inhaled in the first half of the inhalation period. The volume reaching the alveoli is said to be 67-75% of the human tidal volume. The gas inhaled at the end of the inspiratory period does not reach the alveoli, but remains in the anatomical dead space such as the airways and bronchi, and the gas accumulated in the anatomical dead space immediately follows. Exhaled and excreted out of the body.
Therefore, a therapeutic effect cannot be expected by sending a therapeutic gas having a high concentration at the end of the inspiration period.

In order to inhale the therapeutic gas into the user 7 efficiently, it is desirable to send the therapeutic gas at a high concentration to the user 7 in the first half of the inspiratory period during which the gas can reach the alveoli. Generally, when humans inhale gas,
The largest intake flow rate occurs during the first half of the intake period. Therefore,
In order to allow the most therapeutic gas to reach the alveoli, it is desirable to send a high concentration of the therapeutic gas to the user 7 at the timing with the highest inspiratory flow during the inspiratory period. The present invention takes advantage of such characteristics of human respiration to efficiently supply a therapeutic gas.

The optimum volume in the conduit differs for each user depending on the tidal volume, the respiration rate of the user 7 and the ventilation setting of the respirator body 1. It can be determined from the flow pattern in the conduit from the therapeutic gas inlet port 4 to the exhalation vent 3 when breathing.

FIG. 6 shows a general flow pattern from the respirator body 1 to the user in the conduit when the therapeutic gas is mixed, and a respiratory flow pattern of the user 7 at that time. From inspiration to expiration, when the flow rate in the conduit decreases,
Mixed gas is stored in the conduit from the therapeutic gas mixing port 4 to the exhalation discharge hole 3, and when the flow rate in the conduit is minimum, that is, when the exhalation flow rate is maximum, the mixed gas concentration near the gas mixing port position is the highest. After that, the high-concentration mixed gas moves toward the user as it moves from exhalation to inspiration.

In order to inhale the stored high-concentration gas when the intake flow rate is the highest during the inspiration period, the flow rate in the conduit is maximized from the time when the flow rate in the conduit is minimum (the maximum expiratory flow rate), which is indicated by the diagonal line in FIG. It is sufficient that the integrated value of the flow rate moving in the conduit up to the time (maximum inspiratory flow rate) corresponds to the volume in the conduit from the therapeutic gas mixing port 4 to the mask.

The following method can be considered as a method for determining the optimum internal volume of the conduit for the user 7. A flow meter is connected to a conduit between the therapeutic gas mixing port 4 and the mask, and the therapeutic gas and the respiratory assist device main body 1 are set in accordance with the prescription conditions of the user 7, and the user 7 is rested or breathed. Have them sleep and breathe. Data obtained by the flow meter is taken in as numerical data through the A / D conversion board. The integral value is determined, and the volume inside the conduit is determined. The flow pattern at the time of rest breathing may be about 10 patterns and an average value may be taken.

In many cases, the user 7 determines the optimum volume in the conduit when he or she has a daytime diagnosis at a hospital. On the other hand, if it is during sleep that the actual intermittent positive pressure ventilation is actually performed, the breathing pattern during awakening during the day is different from that during sleep. 0.7
It is preferable to determine the value in the range of up to 1.3 times. When a respiratory test is performed during nighttime sleep, it is preferable to provide the therapeutic gas mixing port 4 at a conduit position having a volume equal to the optimal inner volume of the conduit, that is, the volume of gas passing through the conduit 2.

FIG. 7 shows a preferred embodiment of the intermittent positive pressure breathing assist device of the present invention. A cylindrical gas-mixing connector 8 capable of connecting both ends to the conduit 2 was prepared, and the therapeutic gas could be injected perpendicular to the connector 8. The conduit 2 is cut and used based on the volume of the conduit that is optimal for the user 7.

Alternatively, as shown in FIG. 8, the therapeutic gas mixing tube 9 is inserted into the conduit from a position where the internal volume of the conduit can be sufficiently taken, and the therapeutic gas is moved to a position where the internal volume of the conduit is optimized. It is also possible to adopt a method of bringing the tip of the mixing tube, and in this case, it is not necessary to cut the conduit 2. Further, as the conduit of the present invention, a conduit having an irregular cross section can be naturally used.

As the therapeutic gas, the above-mentioned oxygen may be used. In addition to this, even when any therapeutic gas such as NO or anesthetic is used, a high-concentration therapeutic gas is used according to the same principle. Can be inhaled.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to make sure that the volume inside the conduit has an optimum volume, the volume of the therapeutic gas mixing port 4 attached to the mask frame 5 and the volume of the conduit from the mask to the therapeutic gas mixing port 4 are 560 cm ^3. The experiment was conducted with the therapeutic gas mixing port 4 provided at a position where the gas concentration became 1,200 cm ³ , and the concentration of the therapeutic gas in the nares at the time of inhalation was compared.

[Example 1] Using the apparatus of FIG. 7 of the present invention, oxygen gas at a constant flow rate of 94% was mixed as a therapeutic gas into five adults, and a nasal mask type intermittent positive pressure was used. The patient was breathed with a respiratory assist device. From the respiratory flow measurement of five people,
The average value of the gas volume passing through the conduit 2 from the time corresponding to the maximum value of the expiratory flow to the time corresponding to the maximum value of the inspiratory flow was 560 cm ³ .

The position of the therapeutic gas mixing port 4 was set to a conduit position having an inner volume of 560 cm ³ from the mask end side, and oxygen gas was continuously mixed at 5 L / min. The settings of the respirator body 1 are: inhalation pressure 18 cmH ₂ O, expiration pressure 4
cmH ₂ O, the inhalation time was 1.5 seconds, and the expiration time was 2 seconds. The nasal mask 6 used had a small amount of rebreathing in which the exhalation discharge hole 3 was located in front of the nostril.

Comparative Example 1 Using the apparatus of FIG. 7 of the present invention,
The treatment gas mixing port 4 is set at 1200c from the end of the mask.
It was provided at the position of the conduit having an internal volume of m ³ , and the other conditions were the same as in Example 1, and the patient was breathed with a nasal mask type intermittent positive pressure breathing assist device.

COMPARATIVE EXAMPLE 2 Using the apparatus shown in FIG. 1, oxygen was directly mixed into the mask from the therapeutic gas mixing port 4 provided on the mask, and the other conditions were the same as in Example 1, except for the nasal mask. The patient was breathed with an intermittent positive pressure breathing assist device.

The average respiratory flow pattern and oxygen concentration in the nostril when 5 L / min of oxygen gas is mixed are shown in FIG. 3, FIG. 4 and FIG.

In the respiration at the therapeutic gas mixing port 4 attached to the mask frame 5 (FIG. 3), the peak of the oxygen gas concentration is only about 30% at the maximum, and the largest inhalation flow rate during the inspiration period. Before the concentration peak appears.

On the other hand, when oxygen gas is mixed from a position where the volume in the conduit from the mask to the therapeutic gas mixing port 4 becomes 560 cm ³ (FIG. 4), the mixed oxygen gas is stored in the conduit. As a result, oxygen gas of up to about 40% was supplied to the user 7. Further, as indicated by the arrow, the oxygen gas of the highest concentration can be inhaled when the inhaled amount is the largest during the inhalation period, and efficient oxygen inhalation is possible.

Further, the treatment gas mixing port 4 is connected to the mask.
The breathing pattern when oxygen gas is mixed from a place where the internal volume of the pipe is 1200 cm ³ (Fig. 5) can store oxygen gas mixed in the pipe, so inhale up to about 40% of oxygen gas. However, since the volume in the conduit from the mask to the therapeutic gas mixing port 4 is too large,
When the amount of inhalation is the largest during the inhalation period indicated by the arrow, the peak concentration oxygen gas has not yet reached the inside of the body, and the oxygen gas having the peak concentration flows only at the end of inhalation. As described above, even if high-concentration oxygen gas is supplied at the end of the inspiration period, it is meaningless because it is discharged outside the body before reaching the alveoli.

Using the average value of the five stable breaths, the inspired oxygen amount (oxygen concentration × respiratory flow is integrated during the inspiratory period) and the tidal volume (inspiratory flow is integrated during the inspiratory period) are calculated. Tidal volume was compared as the average inspired oxygen concentration during inspiration.

As a result, an apparatus in which a therapeutic gas mixing port is provided at a position such that the average value of the average inhaled oxygen concentration of five persons is 1200 cm ³ in the conduit (Comparative Example 1): Treatment with a conventional mask Provided with a gas mixing port for use (Comparative Example 2): Intermittent positive pressure breathing assist device of the present invention (Example 1)
However, the intermittent positive pressure respiratory assist device of the present invention showed a clearly higher inhaled oxygen concentration of 27%: 28%: 33%.

[0038]

By using the intermittent positive-pressure respiratory assist device of the present invention, the therapeutic gas mixing port 4 is provided at a position where the volume of the conduit from the mask to the therapeutic gas mixing port 4 is optimized. It was found that oxygen gas of high concentration can be efficiently inhaled during inhalation.

[Brief description of the drawings]

FIG. 1 shows a device generally used for nasal mask type intermittent positive pressure ventilation.

FIG. 2 is a nasal mask having an exhalation vent in front of a user's nares.

FIG. 3 shows a breathing pattern and a nostril oxygen concentration pattern when oxygen gas is mixed from a gas mixing port attached to a mask frame.

FIG. 4 shows a breathing pattern and a nostril oxygen concentration pattern when oxygen gas is mixed from a position where the volume in the conduit from the mask to the therapeutic gas mixing port 4 is 560 cm ³ .

FIG. 5 is a respiratory pattern and a nostril oxygen concentration pattern when oxygen gas is mixed from a position where the internal volume of the conduit from the mask to the therapeutic gas mixing port 4 is 1200 cm ³ .

FIG. 6 is a flow pattern in a conduit when gas is mixed.

FIG. 7 is a schematic diagram of a preferred intermittent positive pressure breathing aid of the present invention.

FIG. 8 is a schematic diagram of a preferred intermittent positive pressure breathing aid of the present invention.

[Explanation of symbols]

 1. Respirator body 2. Conduit 3. Exhalation vent 4. 4. Therapeutic gas mixing port Mask frame 6. Nasal mask 7. User 8. 8. Cylindrical gas mixing connector Therapeutic gas mixing tube

Claims (4)

[Claims] 1. A respiratory aid for intermittently supplying positive-pressure air in response to a user's breathing, a respiratory mask for supplying the user with positive-pressure air, and the respiratory aid and the respiration Positive pressure type respiratory assist device provided with conduit means for connecting a mask for medical use, comprising a therapeutic gas mixing port for mixing a therapeutic gas in the middle of the conduit means. . 2. The conduit according to claim 1, wherein a volume of the conduit from the position of the gas mixing port to the respiratory mask is from a time corresponding to a maximum value of a user's expiratory flow to a time corresponding to a maximum value of an inspiratory flow. The intermittent positive pressure breathing assist device according to claim 1, wherein the volume of the gas passing therethrough is 0.7 to 1.3 times. 3. The conduit according to claim 1, wherein a volume of the conduit from the position of the gas mixing port to the respiratory mask is from a time corresponding to a maximum value of a user's expiratory flow to a time corresponding to a maximum value of an inspiratory flow. The intermittent positive-pressure respiratory assist device according to claim 1, wherein the volume of gas passing therethrough is equal to the volume of gas passing therethrough. 4. The intermittent positive pressure breathing assist device according to claim 1, wherein the therapeutic gas is oxygen.