JP2001170178A - High frequency respirator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a high frequency artificial respiration by a desired ventilation volume. SOLUTION: This high frequency respirator has an inspiratory gas-introducing section 62 for an inspiratory gas-feeding source, a vibration air pressurizing section 50 which energizes a high frequency vibration air pressure to an inspiratory gas, a patient side path 60 which introduces the inspiratory gas to a patient X, a discharge path 604 which discharges an exhalation gas, a section 171a to be fitted for an endotracheal insertion tube 81, and an internal pressure regulator 607 which regulates an average respiratory tract internal pressure. In addition, the high frequency respirator has a controller 40 equipped with a receiving section 41, a motion-control section 49, a map memory 42 and an assigning section 45. In this case, the receiving section 41 receives the setting inputs for the tidal volume for the lung of a patient X, a vibration frequency, an inspiratory gas-feeding amount, the average respiratory tract internal pressure, and the diameter of the endotracheal insertion tube. The motion-control section 49 performs a motion control based on the set values. The map memory 42 stores a five-dimensional map wherein the set values are used as the parameters for the output assignment of the vibration air pressurizing section. The assigning section 45 assigns the output of the vibration air pressure-energizing section based on the five-dimensional map and respective set values, and performs the motion control of the vibration air pressure- energizing section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency ventilator, and more particularly to a high-frequency ventilator capable of supplying oxygen while specifying a tidal volume for a patient's lung.

[0002]

2. Description of the Related Art A conventional high-frequency ventilator 200 is shown in FIG.
As shown in FIG. 3, the three-way branch pipe 20 is
Inhalation containing high concentration oxygen (normal flow rate of 10 to 30 [l / m]) flowing through a fluid circuit system branched to the patient X side and the exhaust side via
in], up to 60 [l / min]), the frequent (about 3 to 15 [Hz]) oscillating air pressure is urged by the oscillating air pressure urging unit 203 to supply oxygen to the lungs of the patient X. . At this time, the average pressure applied to the lungs of the patient X is controlled by the closed release area of the rubber valve of the exhalation valve 204 provided at the exhalation outlet, and the normal average pressure is 5 to 15 [cmH ₂ O]. Set to keep.
Reference numeral 205 in the drawing denotes an endotracheal insertion tube that is inserted from the patient side end of the three-way branch tube 202 to near the first branch of the patient's trachea.

[0003] The oxygen supply principle of the high-frequency ventilator 200 will be described. First, when a high-frequency oscillating air pressure is applied to the inhalation supplied to the patient X, the pressure amplitude of the inspiration causes the inspiration including the carbon dioxide in the lungs of the patient X (hereinafter referred to as exhalation). A small volume of ventilation (convective gas exchange) occurs, and due to the effect of diffusion movement due to the vibration of the inspired air, the inspired air enters the lungs and the expiration in the lungs is guided to the outside of the lungs (the mouth of the patient). The subsequent inhalation has the function of performing the above-mentioned ventilation and sending out the exhaled air derived from the lungs to the exhaust port side. This makes it possible to always maintain a constant oxygen concentration in the lungs of the patient.

[0004]

However, with the above-described high-frequency ventilator 200, it was not possible to set the tidal volume for the patient's lungs.

The circulating air pressure urging means 203 of the high-frequency ventilator 200 includes a blower for simultaneously outputting positive pressure and negative pressure from separate output units, and a negative pressure output of the blower. And a rotary valve for alternately connecting a unit and a positive pressure output unit to a path for supplying inspiration to the patient.

Accordingly, the setting of the tidal volume (the supply amount of intake air per one cycle of the oscillating air pressure) in the oscillating air pressure urging means 203 is adjusted by increasing the output of the blower. Since the motor is rotated, the output of the blower itself is adjusted by adjusting the output of the motor.)

[0007] However, in the high-frequency ventilator 200, the path of the supplied inspiration is branched to the patient side and the discharge side,
Since the intake air with some oscillating air pressures directly flows to the discharge side, the tidal volume with the oscillating air pressure urging means is
In fact, it did not match the tidal volume for the patient's lungs.

[0008] Therefore, a person (eg, a doctor) operating a high-frequency ventilator cannot recognize the tidal volume of the lungs, and knows whether or not the high-frequency ventilation is effectively performed on the lungs. It was difficult.

FIG. 14 is a graph showing the result of measuring the tidal volume in the test lung by changing the cycle of the oscillating air pressure by changing the cycle of the oscillating air pressure. FIG. This measurement is performed by maximizing the blower output and maximizing the tidal volume by the oscillating air pressure urging means 203. FIG. 14 shows an inner diameter of 4.
FIG. 15 shows a test result of the tracheal insertion tube 205 of 0 [mm].
Shows the test results of the endotracheal tube 205 having an internal diameter of 8.0 [mm].

FIGS. 16 and 17 show the results of measuring the tidal volume in the test lung by changing the diameter of the endotracheal tube used in the same manner. This measurement is performed by maximizing the blower output and maximizing the tidal volume by the oscillating air pressure urging means 203. FIG. 16 shows the test results when the ventilation frequency is 6 [Hz], and FIG. 17 shows the test results when the ventilation frequency is 15 [Hz].

[0011] The test lung is a closed container having a fixed volume similar to that of a human lung, and is connected to and communicated with the distal end of the endotracheal insertion tube 205 on the insertion side. The test lung is equipped with a pressure sensor for detecting the internal pressure. C shown in each of FIGS. 14 to 17 indicates the volume of the model lung. That is, in FIGS. 14 to 17, the model lungs are 8, 12, 16
It shows the results of a test performed for three volumes [l].

As can be seen from FIGS. 14 to 17, the actual tidal volume in the test lung varies greatly depending on the inner diameter of the endotracheal tube 205 and the vibration frequency of the oscillating air pressure.

The cause of this is that the flow of high frequency air vibration is in a turbulent state, and the magnitude of the pipe resistance is significantly affected by the vibration frequency and the inner diameter of the tracheal insertion tube. This is because the reached tidal volume is strongly affected.

As described above, since the tidal volume in the lungs varies depending on many parameters, a person (eg, a doctor) operating a high-frequency ventilator can reduce the tidal volume by the oscillating air pressure urging means. Estimating tidal volume in the lungs was also difficult.

Further, if there is a flow sensor capable of actually detecting the ventilation volume of inspiration and expiration in the lungs of a patient undergoing high-frequency artificial respiration, the tidal volume in the lungs can be easily detected. Since there is currently no small responsive flow sensor suitable for measuring the flow of air vibration, it has also been difficult to directly detect the tidal volume in the patient's lungs.

[0016]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-frequency ventilator which can solve the inconveniences of the prior art and set a tidal volume in the lungs of a patient and perform high-frequency artificial respiration. Aim.

[0017]

According to the first aspect of the present invention, an inhalation introducing section for supplying an inhalation containing oxygen to a patient, a patient-side path for guiding the inhalation from the inhalation introducing section to the patient, A vibration air pressure urging unit that urges the vibration air pressure of a cycle shorter than the patient's breathing cycle to the inhalation flowing through the patient side path, and an exhaust path that discharges exhaled air containing carbon dioxide emitted from the patient to the atmosphere, An internal pressure control unit that adjusts the average airway pressure in the patient-side path, and a controller that controls the operation of each unit are provided, and a tracheal insertion tube having a diameter corresponding to the trachea of the patient is selected at the patient-side end of the patient-side path. A mounted portion to be mounted is provided.

The controller receives the setting input for the tidal volume for the patient's lungs, the vibration frequency of the oscillating air pressure, the supply amount of inspiration, the average airway pressure, and the diameter of the selected endotracheal tube. And an operation control for the oscillating air pressure urging unit, the inhalation introducing unit, and the internal pressure adjusting unit based on the oscillation frequency of the oscillating air pressure input to the reception unit, the supply amount of inspiration, and the average airway pressure in the patient side path. The control unit performs the tidal volume to the lungs of the patient, the vibration frequency of the oscillating air pressure, the supply amount of inspiration, the average airway pressure, and the diameter of the selected endotracheal tube, and the output of the oscillating air pressure urging unit. The output of the oscillating air pressure urging unit is specified from a map memory storing a five-dimensional map as a parameter for specifying the oscillating air pressure, and the input value received by the receiving unit. It adopts a configuration that includes a specification unit for controlling the operation of the biasing portion.

In the above configuration, first, the tidal volume of the patient's lungs, the vibration frequency, the inspiratory supply amount, the average airway pressure, and the outer diameter of the used tracheal insertion tube are input to the receiving unit of the controller from the outside. Is performed. Here, "the tidal volume of the patient's lungs" indicates the ventilation volume of inspiration and expiration in the patient's lungs in one cycle of the oscillating air pressure.
Such an input is input by an operator of the high-frequency ventilator via information input means such as a higher-level device or a personal computer connected to the controller.

The specifying unit applies the numerical values input to the receiving unit to the five-dimensional map stored in the map memory and specifies the magnitude of the oscillating air pressure based on these numerical values. Here, the “magnitude of the oscillating air pressure” refers to, for example, the pressure amplitude of the oscillating air pressure or the output of the drive source of the oscillating air pressure urging unit in a proportional relationship with the amplitude.

Then, the operation control section causes the intake introduction section to supply the intake air at the input intake air supply amount. Further, the operation control unit and the specifying unit cause the oscillating air pressure urging means to generate oscillating air pressure at the input vibration frequency and at the specified output. As a result, the inspiration generates a pressure amplitude, and a small volume of ventilation (convective gas exchange) occurs with respect to the inspiration containing carbon dioxide (hereinafter referred to as exhalation) in the lungs of the patient, and the oscillation of the inspiration Inhalation enters the lungs via the endotracheal tube and expiration in the lungs is led out of the lungs (to the patient's mouth) due to the effect of the diffusing movement. Subsequent inspiration has the effect of performing the above-mentioned ventilation and sending out the exhaled air derived from the lungs to the discharge path side.

Further, the operation control section adjusts the internal pressure adjusting means so that the average airway pressure in the patient side path is inputted. Here, the “average airway pressure” refers to the average value of the inspiratory pressure in the patient side path that rises and falls due to the oscillating air pressure.

According to a second aspect of the present invention, there is provided a configuration similar to that of the first aspect of the present invention, and the tidal volume to the lungs of the patient, the oscillating frequency of the oscillating air pressure, the supply amount of the inspired air, the average airway pressure and the selection. The input means for inputting the diameter of the inserted endotracheal tube to the receiving unit is provided in the controller. In such a configuration, the same operation as that of the first aspect of the invention is performed, and the above-described numerical values are input from the input unit.

According to the third aspect of the present invention, the first or second aspect is provided.
The present invention has a configuration similar to that of the described invention, and a configuration in which a display unit that displays each value set and input to the reception unit is provided in the controller. In such a configuration, the same operation as the first or second aspect of the present invention is performed, and the values set and input are displayed on the display unit.

According to the fourth aspect of the present invention, the same configuration as that of the first, second or third aspect of the present invention is provided, and the five-dimensional map includes the output of the oscillating air pressure urging unit, the oscillating frequency of the oscillating air pressure, and the intake air pressure. It is constructed based on the test data of a test that measures the tidal volume at the tip of the endotracheal tube by changing the supply amount, the average airway pressure, and the diameter of the selected endotracheal tube. Has been adopted. In other words, this five-dimensional map connects the endotracheal tube to a high-frequency ventilator, sets the tidal volume at the insertion side end of the endotracheal tube, and sets all the above-mentioned parameters in each use range. It is measured by changing it within the range and created from all the test data. Therefore, since the correlation between each parameter and the tidal volume becomes clear, by specifying the tidal volume, the vibration frequency, the inspiratory supply volume, the average airway pressure, and the diameter of the endotracheal tube, it is calculated backward. The magnitude of the oscillating air pressure corresponding to this can be specified. That is, since the output of the oscillating air pressure urging unit for obtaining the desired tidal volume is known, the operator can freely set the tidal volume for the patient's lung.

The present invention is intended to achieve the above-mentioned object by each of the above-mentioned constitutions.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Overall Configuration of Embodiment) An embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 1 is a block diagram illustrating a configuration of a high-frequency ventilator 12 according to the present embodiment.

This high-frequency ventilator 12 is connected to the patient X
An intake unit 62 that supplies inspired air containing oxygen to the patient, a patient-side path 60 that guides the inhaled air from the intake unit 62 to the patient X, and a respiratory cycle of the patient X for the inhalation flowing through the patient-side path 60. The vibration air pressure urging unit 50 for urging the vibration air pressure having a short cycle, and a discharge path (discharge pipe 604) for discharging the exhaled air containing the carbon dioxide emitted from the patient X to the atmosphere.
And a discharge path 604 as a patient side path 60 and a discharge path.
And a controller 40 for controlling the operation of each part of the ventilator 12.

Hereinafter, each part will be described in detail.

(Intake Introducing Portion) The intake introducing portion 62 is connected to oxygen and air supply sources 621a and 621b, and is a blender 621 as first adjusting means for mixing these.
And a humidifier 622 for humidifying the air sent from the blender 621.

Oxygen and air supply sources 621a, 621b
Is composed of a cylinder in which they are sealed and a supply valve provided in a hospital facility. These supply sources 621a and 621b always supply oxygen and air to the blender side at a constant pressure.

The blender 621 is connected to each of the supply sources 621a,
There is a valve (not shown) for adjusting the flow rate at the connection with the 21b, and these can be adjusted to freely set the oxygen concentration of the intake air. Further, the blender 621 is provided with an output valve (not shown) capable of adjusting the flow rate of the intake air flowing to the humidifier 622 side. The setting of the oxygen concentration and the flow rate of the intake air can be freely performed by receiving an operation signal from the controller 40.

The humidifier 622 is connected to an inspiratory pipe 623 for supplying humidified inspired air to the patient X. Intake pipe 6
23 is branched in the middle thereof, and one end is communicated with a pressurized chamber 563 of a diaphragm mechanism 56 described later,
The other end is connected to a three-way branch pipe 170 described later.

(Vibration air pressure urging unit) Vibration air pressure urging unit 5
Reference numeral 0 denotes a blower 52 that simultaneously generates both positive and negative air pressures, a rotary valve mechanism 54 that alternately selects the positive or negative pressure generated by the blower 52 and converts the positive or negative pressure into a predetermined oscillating air pressure, A diaphragm mechanism 5 that is operated by being urged by the oscillating air pressure from the valve mechanism 54, and urges the oscillating air pressure to the intake air supplied to the patient X from the inspiratory introduction unit 62
6 is adopted.

The above-mentioned blower 52 simultaneously generates positive pressure and negative pressure by taking in air therein and sending out the air. The air intake of the blower 52 is
Negative pressure port 542 of rotary valve mechanism 54 described later
, And the air outlet is connected to the positive pressure port 541.

The blower 52 has a fan and a motor for driving the fan. This motor has an inverter, and the output of the motor is controlled by the controller 40 to set the amount of air to be sent and the magnitude (pressure amplitude) of the oscillating air pressure Apn.

The rotary valve mechanism 54 includes a positive pressure port 541 to which positive pressure is input from the blower 52, a negative pressure port 542 to which negative pressure is applied from the blower 52, and an output port 543 for outputting oscillating air pressure. It comprises a rotary valve 544 for alternately connecting the output port 543 to the positive pressure port 541 and the negative pressure port 542 by its own rotation, and a drive unit 545 for rotating the rotary valve 544.

The drive unit 545 includes a motor and a speed reducer (not shown).
Rotate at the number of revolutions specified at 0. Each time the rotary valve 544 makes one rotation, the port 541 and the port 5
43 and once only, and then only the port 542 and the port 543 once. Therefore, the oscillating air pressure Apn having an oscillating frequency proportional to the rotation speed of the driving unit 545 is applied to the supplied intake air. The controller 40
By controlling the rotation speed of the driving unit 545, the vibration frequency (ventilation frequency) of the oscillating air pressure Apn is controlled.

The controller 40 also controls the amount of air sent from the blower 52, as described above, and sets the amount of air sent in accordance with the vibration frequency to thereby control the amount of air supplied to the oscillating air pressure urging unit. It is possible to freely set the tidal volume (amplitude per oscillation cycle of the oscillating air pressure Apn).

The port 543 has a vibration air pressure Apn.
Pneumatic tube 546 for transmitting pressure to diaphragm mechanism 56
Is connected.

The diaphragm mechanism 56 includes a pressurizing chamber 562 and a pressurized chamber 563, and a diaphragm 561 formed of a stretchable film-like member that partitions between the pressurizing chamber 562 and the pressurized chamber 563. Have. The pressurizing chamber 562 is connected to the oscillating pneumatic tube 546. The pressurizing chamber 562 is connected to an output port 543 of the rotary valve 54, and the pressurized chamber 563 is connected to an intake pipe 623.
With such a structure, the oscillating air pressure formed by the rotary valve 54 is urged by the intake air flowing through the intake pipe 623 through the diaphragm 561. This diaphragm mechanism 5
6, the flow of gas between the oscillating air pressure urging unit 50 and the patient X is shut off to prevent mutual contamination.

(Patient-side route) The high-frequency ventilator 12 further includes a three-way branch pipe 170 downstream of the inspiratory pipe 623, and the three-way branch pipe 170 further extends the downstream side between the patient X side and the discharge route side. It has branched to. This three-way branch pipe 170
Has three lines, a patient-side line 171, an oxygen supply-side line 172, and an exhalation discharge-side line 173, all of which communicate internally. The oxygen supply side pipe 172 is connected to the intake pipe 623. The patient-side conduit 171 has, at the patient-side end thereof, the mounting portion 17 to which the intratracheal insertion tube 81 reaching the lungs of the patient X is freely mounted.
1a is formed.

The three-way branch pipe 170 and the intake pipe 623
And the intratracheal insertion tube 81 constitute the patient-side path 60. Further, a patient-side pressure sensor 93 that detects an average airway pressure is provided in the patient-side conduit 171, and the detected pressure is output to the controller 40.

The endotracheal insertion tube 81 has a proximal end attached to the above-mentioned attached portion 171a, and a distal end inserted into the trachea through the mouth of the patient X. Such a distal end is inserted up to a branch point (first branch) where the trachea roughly branches into left and right bronchi. Therefore, the endotracheal insertion tube 81 is set to have a length sufficient to reach from the mouth of the patient X to the first branch, and of course, has an outer diameter that can be inserted into the trachea.

For example, in the case of an adult male, the distance from the mouth to the first branch is about 22 to 26 [cm].
Since the length from the patient-side conduit 171 to the mouth is +3 to 5 [cm], the total length of the endotracheal insertion tube 81 may be about 25 to 31 [cm]. Set to 30 [cm].
Further, the endotracheal insertion tube 81 has an inner diameter of 3 [mm], 5 [mm],
Four types of 6 [mm] and 8 [mm] are prepared, and a type corresponding to the inner diameter of the patient's trachea is selected and used. Generally, when targeting a normal adult, the inner diameter of the tracheal insertion tube 81 is 8 [m
m].

Further, the intratracheal insertion tube 81 is of an exchangeable type, and is detachable from the mounting portion 171a. Therefore, after it is used for artificial respiration, it is removed, discarded or sterilized, washed and reused.

(Exhaust Path) Further, the expiratory discharge side pipe 173 of the three-way branch pipe 170 is connected to the discharge pipe 60 as a discharge path.
4 is connected to one end, and the other end of the discharge pipe 604 is connected to a flow control valve 607 as an internal pressure control unit. The discharge pipe 604 and the flow control valve 607 are a passage for inspiration (expiration) containing carbon dioxide discharged from the lungs of the patient X.

FIG. 2 is an enlarged view in which the periphery of the flow rate control valve 607 is partially cut away. As shown in this figure, a flow control valve 607 includes a housing 607a, an exhaust port 607b, a moving valve (control silicon sheet) 607c for controlling the flow, and a reciprocation for moving the moving valve 607c forward and backward along a certain direction. Solenoid 6 as urging mechanism
07d.

The solenoid 607d is connected to the controller 4
The moving valve 607c is moved by the moving amount according to the control signal from 0, whereby the exhalation discharge amount of the flow control valve 607 can be freely adjusted. The patient side path 60 is the exhaust pipe 6
Since it is in communication with the exhaust pipe 04, it is possible to adjust not only the exhaust pipe 604 but also the airway pressure of the patient side channel 60 by adjusting the exhaled air volume.

(Controller) Next, the controller 40
Will be described with reference to FIGS. 1 and 3. FIG. 3 is a block diagram showing a control system of the high-frequency ventilator 12. The controller 40 is composed of an arithmetic unit including a CPU, a ROM, and an A / D converter, and receives a program for executing operation control of the high-frequency ventilator 12 described later.

The controller 40 includes an operation panel 43 for a doctor (operator of the high-frequency ventilator 12) to input operating conditions of each part of the high-frequency ventilator 12 and a tidal volume for the lungs of the patient X. A display unit 44 for displaying is provided in parallel.

Further, the controller 40 is provided with an accepting section 41 for accepting an operation condition setting input from the operation panel 43.
And an operation control unit 49 for performing operation control on the oscillating air pressure urging unit 50, the intake air introduction unit 62, and the flow rate control valve 607 based on each input value input to the reception unit 41, and a five-dimensional map described later. The stored map memory 42 and 5
An identification unit 45 for identifying the output of the oscillating air pressure urging unit 50 from the dimensional map and each input value received by the accepting unit 41 and driving the oscillating air pressure urging unit 50 with the specified output.

The above-mentioned operation panel 43 is a high-frequency ventilator 1
The physician who is the operator of the second person, the tidal volume to the lungs of the patient, the vibration frequency of the oscillating air pressure (hereinafter referred to as “ventilation frequency”), the supply amount of inspiration, the average airway pressure in the patient side path,
It is an input means including, for example, a keyboard for inputting the selected diameter of the endotracheal insertion tube 81 and the oxygen concentration of the inspired air.

All of these operation conditions input from the operation panel 43 are stored in the reception unit 41. This reception unit 41
Is a memory for temporarily storing, and when each of the above-mentioned operation conditions is newly inputted, the previously stored operation condition is overwritten and updated.

The display section 44 is, for example, a display section composed of a liquid crystal panel, and all the operation conditions input to the reception section 41 under the control of the operation control section 49 are displayed on the display section 44.

The operation control unit 49 refers to the oxygen concentration of the intake air stored in the receiving unit 41 and opens the valves on the supply sources 621a and 621b side of the blender 621 of the intake air introducing unit 62 at a predetermined opening ratio. Perform operation control. At the same time, the operation control is performed to open the output valve of the blender 621 of the intake introduction unit 62 at a predetermined opening with reference to the intake supply amount of the reception unit 41.

The operation control unit 49 refers to the average airway pressure stored in the reception unit 41, and refers to the patient-side pressure sensor 93.
The operation control is performed to adjust the opening of the flow rate control valve 607 so that the detected pressure becomes the stored value.

Further, the operation control unit 49 refers to the ventilation frequency stored in the reception unit 41, and refers to the vibration air pressure urging unit 50.
The drive unit 545 of the rotary valve 54 performs an operation control of adjusting the number of revolutions so as to have the stored ventilation frequency.

Next, the map memory 42 will be described. The map memory 42 uses the desired tidal volume, ventilation frequency, inspiratory supply volume, average airway pressure in the patient side route 60, and the diameter of the selected endotracheal tube 81 as the five variables for the lungs of the patient X. By specifying these, a five-dimensional map that specifies the output of the oscillating air pressure urging unit 50 (more precisely, the output of the drive motor of the blower 52) that realizes the desired tidal volume for the lungs of the patient X is stored. ing.

The five-dimensional map corresponds to the oscillating air pressure urging unit 5.
The output of 0, the vibration frequency of the oscillating air pressure, the supply amount of intake air, the average airway pressure, and the diameter of the selected endotracheal tube are respectively changed to measure the tidal volume at the tip of the endotracheal tube 81. It is constructed based on the test data of the test to be performed.

In other words, this five-dimensional map shows four types of air having different diameters in a state where the supply amount of inspiration, the average airway pressure of the patient side route 60, and the ventilation frequency are changed in each of a plurality of stages. With countless test data measured for the correlation between the output of the drive motor of the blower 52 and the ventilation per cycle due to the oscillating air pressure observed at the insertion side tip of each tracheal insertion tube 81 for each insertion tube 81 Has been built.

Therefore, when the supply amount of inspired air, the average airway pressure and ventilation frequency of the patient side route 60 and the diameter of the endotracheal insertion tube are designated, respectively, the output of the drive motor of the blower 52 and the insertion end of the endotracheal insertion tube 81 are determined. One test data on the correlation with the ventilation volume per cycle due to the oscillating air pressure observed in the part can be specified. In the present embodiment, the ventilation volume per cycle due to the observed oscillating air pressure equipped with a model lung equipped with a pressure sensor at the insertion end of the endotracheal insertion tube 81 is referred to as “tidal volume for the patient's lung”. This is regarded as test data (this point will be described later in “Principle of this embodiment”).

Then, the specifying unit 45 specifies the output of the blower 52 corresponding to the desired tidal volume from the characteristic curve composed of the specified one test data, and uses the specified output to operate the blower 52. By driving the drive motor, high frequency artificial respiration can be performed on the lungs of the patient X at a desired tidal volume.

FIG. 4 shows the structure of the five-dimensional map.
7 will be described with reference to FIG. These drawings are explanatory diagrams for explaining the concept of the five-dimensional map. First, 5-dimensional map includes a first step of the map M to identify the map M _i of the next step (FIG. 4) by specifying the intake supply. Are possible specification of the intake air quantity supplied map M in five levels of the first stage, the map of the second stage are specified to M ₅ For example, if the intake air supply amount is 30 [l / min].

The map M _i of the second stage is the route 60 on the patient side.
Map M of the next stage by designating the mean airway pressure
_ij can be identified (Figure 5: depicts a map of M ₅ as an example). The second designated stage of maps M _i mean airway pressure a ten one step in is possible, for example, mean airway pressure in the map M ₅ of the second stage is _{10 [cmH 2 O] (980} [P
The third stage of the map if a]) is identified in M _56.

The map M _ij of the third stage is represented by the patient side route 60.
The next stage map M by specifying the ventilation frequency of
It can be identified _ijk (Figure 6: depicts a map of M ₅₆ as an example). In the third stage map _Mij , the ventilation frequency can be designated in five stages. For example, if the ventilation frequency is 15 [Hz] in the third stage map _M56 , the final stage map is specified as _M565. You.

The map M _{ijk in the} final stage shows the blower 52 obtained by a measurement test for four types of endotracheal tubes having different diameters under the conditions of the specified inspiratory air supply, the average airway pressure and the ventilation frequency. It is test data about the correlation between output and the tidal volume to the lungs of patient X.
FIG. 7 conceptually illustrates the map M _{565 in the} final stage by a diagram. According to this, the diameter of the endotracheal insertion tube 81 attached to the attachment portion 171a of the patient side channel 60 is 8 [m
m] and it is desired to set the output of the drive motor of the blower 52 to 80% when performing frequent ventilation with the tidal volume for the lungs of the patient X set to 78 ml. I understand.

As another example of the map at the final stage,
Fig. 8 shows the intake air supply rate 30 [l / min] and the average airway pressure 15 [cmH ₂ O] (1
470 [Pa]), final stage map M when ventilation frequency 9 [Hz]
Indicates _5Beta3, intake supply amount 30 in FIG. 9 [l / min], mean airway pressure _{15 [cmH 2 O] (1470} [Pa]), shows the final stage map M _5Beta4 when ventilation frequency 12 [Hz], FIG. 10 shows the intake air supply amount 30 [l / m].
in], mean airway pressure 15 [cmH ₂ O] (1470 [Pa]), ventilation frequency 15
The final stage map _M5β5 at [Hz] is shown.

The five-dimensional map is configured as described above, whereby the supply amount of inspiration, the average airway pressure, the ventilation frequency, the diameter of the endotracheal tube, and the desired tidal volume are specified. Thus, the output of the drive motor of the blower 52 that performs high-frequency artificial respiration with the desired tidal volume can be specified. In the above description, the specification of each parameter is performed stepwise with a fixed width. However, the step width that can be specified may be narrowed by acquiring more test data in advance. As a result, it is possible to more precisely set the tidal volume for the lungs of the patient X.

The specifying section 45 specifies the motor output of the blower 52 for performing high-frequency artificial respiration with a desired tidal volume from the five-dimensional map according to the parameters set and input, and uses the output to specify the drive motor. Is performed by the operation control unit.

(Explanation of the Principle of the Present Embodiment) From various papers on medically studying the mechanics of respiration, the mechanism of the lungs of a patient is generally expressed by the following formula. Note that the compliance described below is an index indicating the ease of inflation of the lung.

ΔP = R · (dΔV / dt) + ΔV / C (1) (ΔP: change in patient's lung pressure [cmH ₂ O (Pa)], R: airway resistance before flowing into alveoli [cmH ₂ O] / l / sec (Pa / l / sec)], C:
Compliance [ml / cmH ₂ O (ml / Pa)], ΔV: Ventilation volume change [ml])

However, the above equation is effective for ordinary artificial respiration which is not frequent (artificial respiration in which oxygen is supplied at substantially the same cycle as the spontaneous respiration of the patient). For reasons, it cannot be applied as is. Because the lungs are constantly pressured evenly (5 to 15
_{[cmH 2 O] (490~1470 [} Pa])), it remains to some extent lung is constantly expanded. Therefore, the movement of the lungs is reduced.
The tidal volume is very small compared to the large and slow ventilation (tidal volume = 500 to 700 [ml], ventilation rate = 8 to 20 [virt / min]) of normal ventilation (100 [ml] or less, ventilation rate is very fast (180 [times / minute] or more). Therefore, the movement of the lung due to ventilation is small. Usually in the case of artificial respiration,
When "inhaling", the instrument actively pushes in.
The instrument is not affected by the exhalation of exhalation, but is naturally affected by the elasticity of the lungs. Therefore, the size of the lung differs between "during inspiration" and "during expiration" even if the lung pressure is the same. In other words, the volume (movement) of the lung differs between "during inflation and deflation", resulting in hysteresis. However, in the gas ventilation of the high-frequency artificial respiration, the instrument actively and forcibly performs a fixed amount of tidal ventilation within a fixed time regardless of the elasticity of the lungs at both the time of inspiration and the time of expiration.
For this reason, the occurrence of hysteresis in the movement of the lung is hardly recognized.

Thus, as an actual patient lung ventilation model, gas is "pushed" into the endotracheal tube as representative of airway resistance and a sealed, non-stretchable, single volume tank as representative of compliance. -It is possible to approximate the state of the ventilation model when "sucking out". Therefore,
The ventilation mechanism based on equation (1) can use the combination of an endotracheal tube and a rigid tank as the model lung of a patient only in the case of high-frequency artificial respiration. The test data for constructing the above-described five-dimensional map was also measured in a test performed by connecting a sealed single-volume tank to the insertion tip of the endotracheal tube.

Here, the test results shown in the description of the prior art will be described with reference to FIGS. 14 to 17. From the experimental data, the following can be understood. The tidal volume varies with the size of the endotracheal tube (from FIGS. 16 and 17). The tidal volume changes with the magnitude of the ventilation frequency (from FIGS. 14 and 15). The tidal volume is almost the same with the size of the model lung (from FIGS. 14 to 17 in general).

To summarize the above, if the output of the oscillating air pressure urging section (more precisely, the output of the blower), the average airway pressure and the inspiratory supply rate are determined, the tidal volume of the patient will be independent of the patient's lungs. It can be seen that it depends on the size of the endotracheal tube and the ventilation frequency.

FIG. 7 shows the case where the ventilation frequency, the average airway pressure, and the inspired air supply amount were fixed, the blower output and the size of the tracheal insertion tube were used as parameters, and a 20 [l] hard tank was selected as a model lung. It is the measurement data of the tidal volume in the case.

For example, if this is used, if the ventilation frequency, the average airway pressure, and the inhalation supply amount are the same, if the endotracheal tube to be used is selected, the desired tidal volume can be achieved. The possible blower output can be calculated backward. In addition, the tidal volume does not depend on the size of the patient's lungs for the reasons described above, so that if the ventilation is performed with the back-calculated blower output, the tidal volume may be considered to be somewhat accurate.

Therefore, in this embodiment, the blower output, the size of the tracheal insertion tube, the ventilation frequency, the average airway pressure, and the inspired air supply amount are used as parameters, and a high-frequency ventilation of the reference model lung is performed. Based on the measured tidal volume, a 5-dimensional map was created.

(Operation of the Present Embodiment) The operation of the high-frequency ventilator 12 having the above configuration will be described below with reference to FIGS. FIG. 11 and FIG.
6 is a flowchart showing the operation of No. 2.

First, the reception unit 41 is in a state of waiting for input of the inner diameter of the endotracheal insertion tube 81 (step S1). When this is input from the operation panel 43, the state of input of the inspiratory supply is next waited (step S2). ). Further, when the intake air supply amount is set and input from the operation panel 43, next, an input of the oxygen concentration of the intake air is waited for (step S3). Further, the operation panel 43
When the oxygen concentration of the intake air is set and input from, the input of the ventilation frequency is awaited (step S4). Further, when the ventilation frequency is set and input from the operation panel 43, next, it waits for the input of the average airway pressure in the patient side path (step S).
5). Further, when the average airway pressure is set and input from the operation panel 43, next, input of the tidal volume for the patient is awaited (step S6).

When the tidal volume for the patient X is input to the reception unit 41, the operation control unit 49 displays the above-described parameters on the display unit 44 (step S7).

Next, in the specifying unit 45, the map memory 42
Of the oscillating air pressure urging unit 50 based on the inner diameter of the endotracheal insertion tube 81 written in the reception unit 41, the inspiratory supply amount, the ventilation frequency, the average airway pressure, and the tidal volume for the patient X while referring to the five-dimensional map of The output of the blower 52 is specified (Step S8).

Further, the specifying unit 45 drives the blower 52 with the specified output. At the same time, the operation control unit 49 sets the intake air introducing unit 62 and the oscillating air pressure urging unit 50 based on the parameters input to the receiving unit 41. And flow control valve 607
Operation control. Thus, the doctor as the operator can perform high-frequency artificial respiration on the patient X with a desired tidal volume (step S9).

When any parameter is newly updated during high-frequency artificial respiration, this is displayed on the display unit 44. Then, based on the changed parameters, high-frequency artificial respiration is performed while controlling the operations of the intake air introduction unit 62, the oscillating air pressure urging unit 50, and the flow rate control valve 607 (step S10).

As described above, the high-frequency ventilator 12
A map in which the controller 4 stores a five-dimensional map in which the tidal volume to the lungs of the patient X, the vibration frequency of the oscillating air pressure, the supply amount of inspiration, the average airway pressure, and the diameter of the selected endotracheal tube are used as parameters. The physician includes the memory 42 and the specifying unit 45 that specifies the output of the blower 52 with reference to the five-dimensional map, so that the doctor does not need to actually measure the tidal volume of the lungs of the patient X. It is possible to perform high-frequency artificial respiration with a single tidal volume.

Further, as in the prior art, the case where high-frequency artificial respiration is performed based on the tidal volume in the oscillating air pressure urging unit 50, which is merely a guide for predicting the tidal volume in the lungs of the patient X, will be described. Differently, patient X is referred to a 5D map.
Since the tidal volume for the lungs is specified, the tidal volume can be adjusted to a desired numerical value with high accuracy.

Further, since the operation panel 43 for inputting each of the above parameters to the reception unit 41 is provided in the controller 40, another independent input means for inputting such parameters is not required. It is possible.

Further, since the display unit 44 for displaying each value set and input to the reception unit 41 is provided in the controller, high-frequency artificial respiration can be performed while checking each input parameter. Thus, the operability of the operator is improved.

Further, since the above-described five-dimensional map is constructed based on the test data of the measurement test, the output of the blower 52 specified is based on the actually measured value, and the tidal volume for the patient X is higher. It becomes possible to match a desired numerical value with accuracy.

[0091]

According to the present invention, a five-dimensional map is used in which the tidal volume to the patient's lungs, the vibration frequency of the oscillating air pressure, the supply amount of inspiration, the average airway pressure, and the diameter of the selected endotracheal tube are used as parameters. And a specifying unit that specifies the output of the oscillating air pressure urging unit with reference to the five-dimensional map, so that the operator of the high-frequency ventilator actually It is possible to perform high-frequency artificial respiration with a desired tidal volume without measuring the ventilation volume.

Further, unlike the conventional case in which high-frequency artificial respiration is performed based on the tidal volume in the oscillating air pressure urging unit, which is merely a guide for predicting the tidal volume in the lungs of the patient, Since the tidal volume for the lungs of the patient is specified with reference to the five-dimensional map, the tidal volume can be adjusted to a desired numerical value with high accuracy.

When the input means for inputting each of the above parameters to the reception unit is provided in the controller, another independent input means for inputting such parameters is not required. Is possible.

Further, when a display unit for displaying each value set and input to the reception unit is provided in the controller, high-frequency artificial respiration can be performed while checking each input parameter. Thus, the operability of the operator is improved.

In the case of construction based on the test data of the above-described five-dimensional map measurement test, the output of the specified oscillating air pressure urging unit is based on the actually measured value. It is possible to adjust to a desired numerical value with higher accuracy.

Since the present invention is configured and functions as described above, according to the present invention, it is possible to provide an excellent high-frequency ventilator which has not been achieved conventionally.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a high-frequency ventilator according to an embodiment.

FIG. 2 is a sectional view showing details of a flow control valve disclosed in FIG. 1;

FIG. 3 is a block diagram showing a control system of the high-frequency ventilator disclosed in FIG.

FIG. 4 is an explanatory diagram illustrating the concept of a map in a first stage of a five-dimensional map.

FIG. 5 is an explanatory diagram illustrating the concept of a second stage map of the five-dimensional map.

FIG. 6 is an explanatory diagram illustrating the concept of a third stage map of the five-dimensional map.

FIG. 7 is an explanatory diagram illustrating the concept of a map at the final stage of a five-dimensional map.

FIG. 8 is another explanatory diagram for explaining the concept of the map at the final stage of the five-dimensional map.

FIG. 9 is still another explanatory diagram for explaining the concept of the map at the final stage of the five-dimensional map.

FIG. 10 is still another explanatory diagram for explaining the concept of the map at the final stage of the five-dimensional map.

FIG. 11 is a flowchart showing the operation of the high-frequency ventilator disclosed in FIG.

FIG. 12 is a continuation of the flowchart of FIG. 11 illustrating the operation of the high frequency ventilator disclosed in FIG. 1;

FIG. 13 is a block diagram showing a configuration of a conventional high-frequency ventilator.

FIG. 14 is a diagram showing test results of the high-frequency ventilator shown in FIG.

FIG. 15 is a diagram showing another test result using the high-frequency ventilator shown in FIG. 13;

FIG. 16 is a diagram showing still another test result using the high-frequency ventilator shown in FIG. 13;

17 is a diagram showing still another test result using the high-frequency ventilator shown in FIG.

[Explanation of symbols]

 12 High-frequency ventilator 40 Controller 41 Reception unit 42 Map memory 43 Operation panel 44 Display unit 45 Identifying unit 49 Operation control unit 50 Vibration air pressure urging unit 60 Patient side route 62 Inhalation introduction unit 81 Intratracheal insertion tube 171a Wearing unit 604 Discharge pipe (discharge path) 607 Flow control valve (internal pressure control unit) X Patient

Claims (4)

[Claims] 1. An inspiratory introduction unit for supplying oxygen-containing inhalation to a patient, a patient-side path for guiding the inhalation from the inspiration unit to the patient, and an inspiration flowing through the patient-side path. An oscillating air pressure urging unit that urges an oscillating air pressure having a cycle shorter than a respiratory cycle, an exhaust path that exhausts exhaled air containing carbon dioxide emitted from the patient to the atmosphere, and an average airway pressure in the patient side path In a high-frequency ventilator comprising: an internal pressure adjusting unit that adjusts the pressure, and a controller that controls the operation of each unit, a mounting part to which a tracheal insertion tube having a diameter corresponding to the trachea of the patient is selected and mounted. The controller is provided at a patient side end of the patient side path, the controller includes: a tidal volume for the patient's lungs, a vibration frequency of the vibration air pressure, a supply amount of the inspiration, the average airway pressure, and the selected trachea. Insertion tube A receiving unit that receives a setting input for the diameter of the oscillating air pressure, and the oscillating air pressure urging based on the vibration frequency of the oscillating air pressure input to the receiving unit, the supply amount of the inspired air, and the average airway pressure in the patient-side path. An operation control unit that performs operation control on the unit, the inhalation introduction unit, and the internal pressure adjustment unit; A map memory storing a five-dimensional map that uses the selected diameter of the endotracheal insertion tube as a parameter for specifying the output of the oscillating air pressure urging unit; and the five-dimensional map and each input received by the receiving unit. An output of the oscillating air pressure urging unit from the value, and a specifying unit for controlling the operation of the oscillating air pressure urging unit based on the output. 2. The receiving unit receives a tidal volume of the patient's lungs, a vibration frequency of the vibration air pressure, a supply amount of the inspiration, the average airway pressure, and a diameter of the selected endotracheal tube. 2. The high frequency ventilator according to claim 1, wherein input means for inputting is provided in said controller. 3. The high-frequency ventilator according to claim 1, wherein a display unit for displaying each value set and input to said reception unit is provided in said controller. 4. The five-dimensional map includes the output of the oscillating air pressure urging unit, the oscillation frequency of the oscillating air pressure, the supply amount of the intake air, the average airway pressure, and the diameter of the selected endotracheal tube. 4. The method according to claim 1, wherein the measurement is performed based on test data of a test for measuring a tidal volume at a distal end portion of the endotracheal insertion tube by changing each of them.
High frequency ventilator as described.