JPH0810331A - Artificial breathing apparatus - Google Patents

Abstract

PURPOSE:To provide a steady-flow type artificial breathing apparatus of a small and simplified structure by which the delay in the initial aspiration flow rate can be eliminated for reducing the breathing workload of a patient and by which oxygen can be added by a convenient oxygen concentrator with little oxygen consumption. CONSTITUTION:An artificial breathing apparatus is provided with a scroll compressor 1, a pressure-relief valve 7 arranged in the aspiration passage 20 that has been connected to the discharge port 1a of the compressor 1 for supplying gas to a patient so as to maintain the internal pressure of the patient's trachea constant, and a bypass valve 9 for returning the surplus aspiration gas that is not aspirated by the patient at the time of breathing to the compressor. By uniting the downstream flow passage of the pressure-relief valve 7 and that of the bypass valve 9, a discharge passage 22 is formed. Further, a compressor intake flow passage 23 by which the discharge passage 22 communicate with the suction port 1b of the compressor 1, and an outside-air intake port 15 is constituted, and also a variable capacity reservoir 16 equipped with an oxygen mixer 17 is connected to the outside air intake port 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilator used for respiratory maintenance and respiratory assistance, and particularly to moderate or mild breathing except for patients with severe respiratory disorders requiring treatment in an intensive care unit. This is a small, lightweight, three-power source (storage battery, automobile power source, home power source) driven respirator for patients with disabilities, and is used in hospital rooms, homes, ambulances, etc.

[0002]

2. Description of the Related Art Conventionally, this type of simple type artificial respirator has
A piston-type pump has been used as a gas compression blower for supplying gas for maintaining breathing and assisting breathing to a patient. FIG.
5 is an explanatory view showing the configuration of a conventional gas supply pump, FIG.
Is the time (sec) on the horizontal axis and the patient's airway pressure (P) on the vertical axis.
FIG. 6 is a diagram showing changes in the airway pressure of the patient during inspiration by taking aw).

In FIG. 4, 30 is an expandable rubber bellows, 31 is a suction valve, 32 is a discharge valve, 33 is a piston, 34 is a feed screw, 35 is a motor, 36 is a rotary encoder, and 37 is a rubber bellows 30. 3 shows a sensor means for controlling the stretch position of the. That is, as the gas supply pump of the conventional ventilator, a piston type pump is used that changes the rotation of the motor 35 into the linear reciprocating motion of the piston 33 and expands and contracts the rubber bellows 30 to inhale and discharge gas. .

In this gas supply pump system, a pressure sensor (not shown) detects that the pressure in the breathing circuit has dropped due to the start of inspiration by the patient, and sends an operation start signal to the motor 35. However, there is a large time lag between when the motor 35 starts rotating and when the inspiration actually reaches the patient, and during that time, the patient's airway pressure becomes negative as shown by M in FIG. This imposes a burden on the patient for the work of breathing, which is contrary to the original purpose of the ventilator for reducing the work of breathing.

Therefore, as a solution to this problem, a constant flow type artificial respirator is known. FIG. 6 is a system diagram showing a configuration of a conventional constant flow type ventilator. In the ventilator shown in FIG. 6, the air discharged from the compressor 1A and passing through the air pressure regulator 40 and the oxygen supplied from a separate oxygen supply source (not shown) and passing through the oxygen pressure regulator 41 are oxygen. Brenda 42
The oxygen concentration is adjusted by and the steady flow whose flow rate is adjusted by the intake flow controller 43 is inhaled by the patient. In case of natural breathing,
Exhaled air from the patient is exhausted from the exhalation valve 10. A pressure gauge 13 and an intake safety valve 14 are provided in the intake circuit to ensure the safety of the intake pressure exerted on the airway of the patient.

In order to open and close the exhalation valve 10, a flow path branched from the intake circuit is provided, and the three-way solenoid valve 11
A, PEEP (Positive Expirato)
ryEnd Pressure: Positive end-expiratory pressure valve 12
A, PEEP pressure control valve 44 is equipped.

In this steady flow type respirator, the exhalation valve 10
Is opened to constantly supply the expiratory flow rate required by the patient and allow the patient to freely breathe. When it is necessary to forcibly pressurize the lungs of the patient, the exhalation valve 10 is closed for that time.

[0008]

As described above, in the gas supply pump system shown in FIG. 4, the response of the device is poor,
At the start of inspiration, the patient's airway pressure becomes negative, which poses a problem of burdening the patient with respiratory work. On the other hand, in the constant flow type ventilator shown in FIG. 6, when oxygen needs to be added, for example, the inspiratory flow rate is 30 l (liter) / m.
30 l at in (min) and oxygen concentration 100%
There is a problem that the oxygen flow rate of / min is required, the oxygen consumption is large, and the oxygen concentrator used at home cannot be used at the oxygen flow rate of 5 to 6 l / min.

Further, as shown in FIG. 6, an air pressure adjuster 40, an oxygen pressure adjuster 41, an oxygen blender 42, an inspiratory flow adjuster 43, etc. are required, and there is a need for a small, lightweight, simple type artificial respirator. There was a problem that was contrary to.

The present invention has been made to solve the above-mentioned problems of the prior art. The first object of the present invention is to eliminate the delay of the initial inspiratory flow rate and reduce the work of breathing of the patient.
It is an object of the present invention to provide a constant-flow type respirator that consumes less oxygen and can add oxygen with a convenient oxygen concentrator.

A second object of the present invention is to provide a small-sized and simplified ventilator which can be driven by three power sources, which does not require a complicated equipment structure such as a conventional device of this kind. is there.

[0012]

In order to achieve the above first object, the most basic constitution of the ventilator according to the present invention is to take in oxygen and air and supply an air-oxygen mixed gas to the inspiration of a patient. In the ventilator to be equipped with a compressor,
A main flow path that is connected to the compressor and supplies the intake gas to the patient is provided with a branch flow path that branches from the main flow path to reach the suction side of the compressor, and the excess intake gas that the patient does not inhale It is provided with a control means for discharging to the road.

Further, in order to achieve the above first object,
A more specific configuration of the ventilator according to the present invention is a ventilator including at least an inhalation circuit that takes in oxygen and air and supplies an air-oxygen mixed gas to the inspiration of a patient, It is equipped with a pressure relief valve for maintaining a constant airway pressure of the patient in the flow path that supplies gas to the patient by connecting to the discharge port of this compressor, and compresses excess inspiratory gas that the patient does not inhale during breathing. A bypass valve for returning to the compressor is provided, and a downstream flow passage of the pressure relief valve and the bypass valve is joined to form a discharge flow passage, and the discharge flow passage, the suction port of the compressor, and the outside air intake. A flow path communicating with the inlet is formed, and a variable capacity reservoir equipped with an oxygen mixer is connected to the outside air intake.

In order to achieve the above second object,
The configuration of the ventilator according to the present invention is, in addition to the configuration of the ventilator described above, configured such that the compressor is a scroll compressor and the rotation speed of the motor is changed to supply a steady flow of a predetermined inspiratory gas flow rate. The control circuit is configured in.

[0015]

The function of the above technical means is as follows. Generally, the maximum amount of oxygen consumed by the patient is 5 to 6 l / m
Since it is in, when the patient does not inhale, the flow rate of the gas that was conventionally released to the outside through the exhalation valve is recovered to the suction port of the compressor through the newly provided bypass channel (release channel). In addition to recirculation, a variable capacity reservoir is provided on the suction side of the compressor, and a mixed gas of the required concentration from the oxygen mixer is stored in the reservoir to supply a gas equivalent to the gas inhaled by the patient. Thereby, the oxygen consumption can be reduced.

With the above new oxygen supply method,
By changing the rotation speed of the motor of the compressor (scroll compressor), it is possible to control the inspiratory flow rate supplied to the patient, so the conventional air pressure regulator, oxygen pressure regulator, and inspiratory flow regulator are abolished. The oxygen blender can also be replaced with a very simple one, and the entire apparatus can be simplified.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is a system diagram of an artificial respirator according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a scroll compressor applied to the present invention, and FIG. 3 is a case of forced respiration in the artificial respirator of FIG. It is a system diagram which shows the gas flow of. In FIG. 1, the same reference numerals as those in FIG. 6 denote the same parts. Also,
1 and 3 show the same device with the same reference numeral.

First, the device configuration of the artificial respirator shown in FIG. 1 will be described. In FIG. 1, reference numeral 1 denotes a compressor having a function of compressing and blowing a mixed gas of air and oxygen. In the present invention, an oilless scroll compressor described later with reference to FIG. 2 is applied. A motor control board 2, a drive board 3, a CPU board 4 such as a microcomputer, an input processing board 5, and a setting input switch board 6 are connected to the compressor 1 to form a control circuit. 7 is a pressure relief valve for keeping the airway pressure of the patient constant, 8 is a pulse actuator for activating the pressure relief valve 7, and 9 is an extra inspiratory gas that the patient does not inhale during natural breathing to the compressor. By-pass valve for returning, 10 is an exhalation valve, 11 is a three-way solenoid valve,
12 is a PEEP valve, 13 is a pressure gauge, and 14 is an intake safety valve.

Reference numeral 15 is an outside air intake provided on the suction side of the compressor 1, and 16 is a variable for storing a mixed gas having a required concentration and supplying a gas equivalent to the gas inhaled by the patient. Volume reservoir (hereinafter simply referred to as reservoir), 17
Is an oxygen mixer, and 18 is an oxygen concentrator or an oxygen flow meter provided in a pipe for supplying oxygen from an oxygen supply source (not shown) to the oxygen mixer 17.

Further, in FIG. 1, 20 is a compressor 1.
The inspiratory flow path 21 from the discharge port 1a of the patient to the patient's airway,
An exhalation flow passage 22 from the patient's airway to the exhalation valve 10 is a discharge flow passage (branch flow passage) obtained by joining the downstream flow passages of the pressure relief valve 7 and the bypass valve 9, and this discharge flow passage 22
Joins the compressor suction flow path 23 together with the outside air intake 15. Reference numeral 23 is a compressor suction flow path connected to the suction port 1b of the compressor 1, 24 is a branch flow path for opening and closing the bypass valve 9 and the exhalation valve 10, and this branch flow path 24 is the intake flow path 20. Is branched from the three-way solenoid valve 11, the PEEP valve 12, the bypass valve 9 and the exhalation valve 10.

Next, an outline of the scroll compressor adopted in this embodiment will be described with reference to FIG. In recent years, scroll compressors are widely used for compressing refrigerant gas in refrigeration cycles such as refrigeration and air conditioning equipment. However, like the air-oxygen mixed gas supply in the ventilator, the scroll compressor is operated under the condition that the airway pressure is low (Max. 0.1 kg / cm ² ) and the flow rate is relatively large (about 20 to 100 l / min). There is no applied example. In the present invention, as a gas compression blower means of a simple steady flow type artificial respirator, as shown in FIG.
As shown in Fig.4, we adopted a small, lightweight, and oil-free scroll compressor of 40w and its control circuit.

The scroll compressor shown in FIG.
01 and the pump part (compression mechanism part) 110 are integrally connected, and the housing 104 on the motor side and the fixed scroll 113 are fastened with a screw 118. Figure 2
, 111 is an orbiting scroll, 112 is a spiral wrap that stands upright on the end plate (equivalent to a mirror plate) face of the orbiting scroll, 113 is a fixed scroll, and 114 is upright on a top plate (equivalent to a mirror plate) face of the fixed scroll. It is a spiral wrap. The wraps 112 and 114 are formed of involute curves and are combined so that the lap portions mesh with each other. Reference numeral 115 is a packing for preventing gas leakage, which is provided at the tip of each wrap.

Reference numeral 102 denotes a rotary shaft that transmits the driving force of the motor 101, and reference numeral 102a denotes an eccentric portion (hereinafter, simply referred to as an eccentric shaft). The boss portion of the orbiting scroll 111 is rotatably attached to the eccentric shaft 102a via a bearing 103. 116 is a hollow disk-shaped slide plate, 117 is a pair of x-axis slide bearings provided on the orbiting scroll 111 side of the slide plate 116, and these are y-axis slide bearings (not shown on the side of the motor 101 side of the slide plate 116). (Provided) and the orbiting scroll 11 when the eccentric shaft 102a rotates.
1 is suppressed, revolves on a circular orbit having a radius of the eccentric dimension, and the orbiting scroll 1 is rotated with respect to the fixed scroll 113.
It constitutes means for causing the 11 to make a turning motion.

The scroll compressor having the above-described structure is provided with the motor 1
By driving 01, gas is sucked into the pump from the suction port 1b provided in a part of the fixed scroll 113, and is sequentially compressed in the compression chamber 119 formed by the orbiting scroll wrap 112 and the fixed scroll wrap 114, which are fixed. It is guided to the discharge port 1a opened in the central portion of the top plate of the scroll 113, and is delivered to the intake passage 20 shown in FIG.

Next, the operation of the artificial respirator of this embodiment will be described. When a required oxygen concentration% is set in the oxygen mixer 17 and oxygen is supplied to the oxygen mixer 17 from a separate oxygen concentrator for home treatment, for example, the oxygen mixer 17 causes the Venturi effect to provide the required outside air. Is taken in, the reservoir 16 swells, and a mixed gas of oxygen and air is stored in the reservoir 16. When the reservoir 16 becomes full, excess gas is released from the release valve 19 to the outside air.

The inspiratory flow rate, the inspiratory pressure and the like required for the patient are set on the setting input switch board 6. The inspiratory flow rate required by the patient is input to the CPU board 4 via the input processing board 5, and C
A command voltage is transmitted from the PU board 4 to the motor control board 2 via the drive board 3. Therefore, the scroll compressor 1
The compressor (hereinafter simply referred to as “compressor”) starts operation at a rotation speed corresponding to the set flow rate pumping, and the pump unit 11 is operated as described above.
The gas compressed in 0 is taken as an intake gas flow in the intake passage 20.
Sent to At this time, a pulse signal corresponding to the rotation speed of a Hall element (not shown) built in the motor 101 is fed back to the motor control board 2 to maintain the rotation speed corresponding to the intake flow rate set, and the intake gas is steadily maintained. Supply flow to the patient.

During natural breathing, as shown in FIG. 1, the three-way solenoid valve 11 in the branch flow path 24 is OFF, and the bypass valve 9 and the exhalation valve 10 are open to the outside air. That is, the balloons related to the valve bodies of the bypass valve 9 and the exhalation valve 10 are flattened.

The intake gas flow exiting the discharge port 1a of the compressor 1 passes through the bypass valve 9 and joins the downstream flow paths of the bypass valve 9 and the pressure relief valve 7 to form a discharge flow path. After passing through 22, the air is sucked into the suction port 1b of the compressor 1 from the compressor suction flow path 23 and circulates. When the patient inhales, the inspiratory gas is supplied to the patient without resistance, and the excess gas passes through the bypass valve 9 and circulates to the compressor 1. In addition, the amount of gas inhaled by the patient is equal to that of the outside air intake port 1 from the reservoir 16.
It is replenished after 5 years.

During forced breathing, the three-way solenoid valve 11 is turned on for the inspiration time set for the set number of breaths per minute. For example, if the breathing rate is 15 times / minute,
The three-way solenoid valve 11 is repeatedly turned on and off at 4-second intervals. The inspiratory time is generally said to be 2 when the inspiring time is 1, but it is decided by the patient.

The flow of inspiratory gas when forced breathing is shown in FIG. When the three-way solenoid valve 11 is turned on, part of the gas in the inspiratory flow path 20 passes through the branch flow path 24 and the expiratory valve 1
0 and the bypass valve 9, the balloon related to the valve body is inflated to close the exhalation valve 10 and the bypass valve 9. The pressure relief valve 7 is spring-loaded to the set intake pressure. The inspiratory gas exiting the compressor 1 reaches the patient via the inspiratory flow path 20 and inflates and pressurizes the patient's lungs. When the airway pressure rises and reaches the set pressure, excess gas is discharged from the pressure relief valve 7 downstream of the valve, circulates through the discharge flow path 22 to the suction port 1b of the compressor 1 and flows to the patient. The gas equivalent amount is replenished from the reservoir 16 through the outside air intake 15.

The set intake time is over and the three-way solenoid valve 1
When 1 is turned off, the gas in the balloon of the exhalation valve 10 and the bypass valve 9 is discharged from the PEEP valve 12, and the exhalation valve 10
And the bypass valve 9 is opened. Therefore, the gas in the patient's lungs is discharged to the outside from the exhalation valve 10 due to the elasticity of the lungs. The gas exiting the compressor 1 passes through the bypass valve 9 as shown in FIG. 1, passes through the discharge passage 22 and the suction port 1b of the compressor 1.
Circulates. Hereinafter, the above intake and exhaust are repeated at a set cycle. Needless to say, the intake flow path 20 is provided with the pressure gauge 13 and the intake safety valve 14 to ensure the safety of the intake pressure exerted on the airway of the patient.

According to the present embodiment, a steady flow in which the delay of the initial inspiratory flow is eliminated to reduce the work of breathing of the patient, the oxygen consumption is small, and oxygen can be added by a convenient oxygen concentrator for home treatment or the like. A mechanical ventilator can be provided. In addition, according to the present embodiment, the conventional apparatus of this type does not require a complicated device configuration such as an air pressure regulator, an oxygen pressure regulator, an oxygen blender, and an intake air flow regulator, and is small and simplified. It is possible to provide a respirator that can be driven by three power sources (storage battery, automobile power source, home power source).

In the above operation, the pressure-controlled ventilation type in which the airway pressure is limited by the set pressure has been described. However, the present invention is not limited to the above, and the pressure-controlled volume that limits the gas volume to be entered into the lungs regardless of the pressure. Ventilated operation is also possible. Further, although not particularly shown, the bypass valve 9, the pressure relief valve 7, and the PEEP valve 12 of the above-mentioned embodiment can be integrated into a pressure relief valve and each operation can be performed according to a time schedule.

[0034]

As described in detail above, according to the present invention, the oxygen in the oxygen concentrator is reduced by eliminating the delay in the initial inspiratory flow rate, reducing the work of breathing of the patient, and reducing the oxygen consumption. It is possible to provide a constant flow type ventilator that can be added. Further, according to the present invention, it is possible to provide a small-sized and simplified ventilator that can be driven by three power sources, which does not require a complicated device configuration such as the conventional device of this type.

[Brief description of drawings]

FIG. 1 is a system diagram of an artificial respirator according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a scroll compressor applied to the present invention.

FIG. 3 is a system diagram showing a gas flow during forced breathing in the ventilator of FIG.

FIG. 4 is an explanatory diagram showing a configuration of a conventional gas supply pump.

FIG. 5 is a diagram showing a change in a patient's airway pressure during inspiration.

FIG. 6 is a system diagram showing a configuration of a conventional steady-flow type ventilator.

[Explanation of symbols]

1 ... Compressor, 2 ... Motor control board, 3 ... Drive board,
4 ... CPU board, 5 ... Input processing board, 6 ... Setting input switch board, 7 ... Pressure relief valve, 9 ... Bypass valve, 10
... exhalation valve, 11 ... three-way solenoid valve, 12 ... PEEP valve, 15
... outside air intake, 16 ... reservoir, 17 ... oxygen mixer,
18 ... Oxygen flow meter, 20 ... Intake channel, 22 ... Release channel.

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[Procedure amendment]

[Submission date] August 10, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

In this gas supply pump system, a pressure sensor (not shown) detects that the pressure in the breathing circuit has dropped due to the start of inspiration by the patient, and sends an operation start signal to the motor 35. However, there is a large time delay until the inspiration reaches the patient when the motor 35 starts rotating, and during that time, the patient's airway pressure becomes negative as shown by M in FIG . This imposes a burden on the patient for the work of breathing, which is contrary to the original purpose of the ventilator for reducing the work of breathing.

Claims (3)

[Claims] 1. A ventilator that takes in oxygen and air and supplies an air-oxygen mixed gas to the inspiration of a patient, comprising a compressor, and connecting the compressor to a main flow path for supplying the inhalation gas to the patient. An artificial respirator, characterized in that a branch flow path that branches from the main flow path to the suction side of the compressor is provided, and control means is provided to release excess inspiratory gas that is not inhaled by the patient to the branch flow path. 2. A ventilator comprising an inspiratory circuit, which takes in oxygen and air and supplies an air-oxygen mixed gas to the inspiratory air of a patient, and at least an exhalation valve, comprising a compressor, and being connected to an outlet of the compressor. In the flow path that supplies gas to the patient, a pressure relief valve for maintaining a constant airway pressure of the patient and a bypass valve for returning excess inspiratory gas that the patient does not inhale during breathing to the compressor are provided. , A discharge flow passage is formed by joining the downstream flow passages of the pressure relief valve and the bypass valve, and the discharge flow passage and the suction inlet of the compressor and the outside air intake constitute a flow passage. In addition, a ventilator characterized in that a variable volume reservoir equipped with an oxygen mixer is connected to the outside air intake. 3. The artificial respirator according to claim 1, wherein the compressor is a scroll compressor, and the rotation speed of the motor is changed to supply a steady flow of a predetermined intake gas flow rate. A ventilator characterized by comprising a control circuit.