JPH0118746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration adder that is used in addition to a respirator or a humidifying inhaler to provide effective respiratory therapy.

<Background> Currently, respiratory management using a ventilator for acute and chronic respiratory failure is generally performed using positive pressure artificial ventilation. This involves intubating a patient, injecting a certain amount of air into the patient through the tube at positive pressure for a certain period of time, and expelling it using the elasticity of the living body's lungs and thorax. The respiratory waveform in this case is as shown in FIG. 1A. Gas exchange, that is, the movement of oxygen or carbon dioxide in this method, is based on Fick's law (the amount of gas passing through a tissue interface is proportional to the area of the interface and inversely proportional to the thickness) and Weibel's airway cross-sectional area model. (The cross-sectional area of the airway increases exponentially with the distance from the entrance.) Considering this, it can be said that this is a method to obtain the required amount of gas movement by setting the tidal volume to more than the dead space, that is, by making the diffusion cross-sectional area sufficiently large. .

The problem with this positive pressure artificial ventilation method is that it is positive pressure breathing, so when the patient's lung and thoracic compliance (volume change per unit pressure) is low,
When excessive positive pressure is applied to the airway alveolar system, the thoracic cavity becomes positive pressure, which adversely affects hemodynamics.

In response to this, recently, as shown in Figure 1B, HFPPV (high frequency positive pressure ventilation) and HFJV (high frequency jet ventilation), which frequently inhale linear gas at positive pressure, have been applied. This is based on Fick's law and
Weibel's airway model departs from the concept of tidal volume and instead involves frequently injecting high-pressure linear gas into the airways to increase the depth of air penetration and frequently artificially create turbulent diffusion. This is a method of adding information.

This method is said to make it possible to ventilate without increasing the airway pressure, even in cases where it would be difficult to do so with conventional methods. However, there are cases where high-pressure jet flow is used or the depth of penetration is uncertain, resulting in low ventilation, and it is thought that it will take time to establish this method along with the theory.

<Summary of the Invention> An object of the present invention is to provide a vibration adder that can be added to a respiratory treatment device to effectively effect respiratory treatment. Another object of the present invention is to provide a vibration adder that can be added to a ventilator to increase gas diffusion in the alveolar system, allowing the tidal volume of conventional breathing methods to reach the critical point of airway pressure and venous return. It is about providing.

The vibration adder of the present invention is inserted into a gas passage between a respiratory treatment device and its connection to a human body, and is configured to periodically change the cross-sectional area of the gas passage. This periodic change causes vibrations to be superimposed on the gas passing through the gas passage. The vibration adder of the present invention is inserted into the gas passageway between the human body and the human body in, for example, a conventional positive pressure artificial ventilation type ventilator, and compares the gas flow of expiration, inspiration, or both with the respiration cycle. to superimpose gas vibrations at a sufficiently high speed.

For example, as shown in FIG. 2, one end of each of an inhalation gas passage 12 and an exhalation gas passage 13 made of a flexible pipe is connected to a respirator 11.
2 and 13 are connected to one end of a common gas passage 14, and the other end of the gas passage 14 is connected to a connecting part 15 to the human body such as a mouthpiece or an insertion tube. The respirator 11 communicates with the lungs 16 of the human body through this coupling portion 15 . A sensor 17 , such as a hot wire flowmeter, is attached to the common gas passage 14 , the sensor 17 is connected to a flowmeter body 18 , and the output of the flowmeter body 18 is recorded on a recorder 19 .

The ventilator 11 is of a positive pressure artificial ventilation type, and during the artificial respiration operation, positive pressure gas is discharged from the ventilator 11 to the intake side gas passage 12 for a certain period of time, and the gas is combined as shown by the arrow 21. Part 1
5 into the lungs 16 and exhaled from the lungs 16 due to the elasticity of the lungs and chest area, the gas is discharged to the respirator 11 through the joint 15 and the exhalation side gas passage 13 as shown by arrow 22. This time recorder 1
The recording of 9 will have a waveform as shown in Figure 1A,
Positive indicates expiration 23 and negative indicates inhalation 24.

The vibration adder 25 according to the present invention is inserted, for example, into the intake side gas passage 12 in FIG. This vibration adder 25 changes the cross-sectional area of the gas passage 12 at a speed sufficiently faster than the breathing cycle of the respirator 11. When this vibration is performed both during expiration and inspiration, the vibrations are superimposed on the gas passing through the inhalation gas passage 12, and the vibrations are of the same magnitude as the gas in the exhalation gas passage 13. Superimpose. The record of the recorder 19 at this time is, for example, as shown in FIG. 1C, in which the vibration 26 is superimposed on the waveform of FIG. 1A. This vibration may be superimposed only during expiration, as shown in FIG. 1D, or may be superimposed only during inspiration, as shown in FIG. 1E.

<Vibration Adder> The vibration adder 25 is configured as shown in FIG. 3, for example. That is, an air supply port 32 is provided on the peripheral wall of the cylinder 31.
This vibration adder is provided with an air supply port 32 and an exhaust port 33, and the gas passage 1 in FIG.
2, 13, or 14. One end of the cylinder 31 is closed with a diaphragm 34 , one end of a drive rod 35 is fixed to the center of the diaphragm 34 , the drive rod 35 projects outward on the axis of the cylinder 31 , and the other end is connected to a vibrator 36 . Ru. The vibrator 36 has a head 38 rotated by the rotation of a motor 37, for example, and a drive rod 35 connected to the head 38 at a point eccentric from the center of rotation. The output of the variable voltage generation circuit 39 is supplied to the drive circuit 41
The motor 37 is rotated by being supplied to the motor 37 through the motor 37. The diaphragm 34 is vibrated at a period corresponding to this rotational speed. In this example, the vibration speed of the diaphragm 34 can be changed as necessary. That is, a DC motor is used as the motor 37, and by adjusting the adjustment section 42 of the variable voltage generation circuit 39, the voltage supplied from the variable voltage generation circuit 39 to the motor 37 through the drive circuit 41 can be adjusted. The motor 37 rotates at a rotational speed depending on the magnitude of the voltage supplied thereto.

As shown in FIG. 1C, D, and E, there are various vibration superimposition modes, and this example shows a case in which these modes can be selected. Flowmeter body 1 in Figure 2
A flow rate signal from 8 is supplied to a wave amplification circuit 44 from an input terminal 43. When the flowmeter sensor 17 is attached to the intake side gas passage 12, this flow rate signal becomes positive in the intake mode and zero in the exhalation mode, and when it is attached to the common gas passage 14, it is shown in Fig. 1A. As shown above, it becomes positive in exhalation mode and negative in inhalation mode. In both cases, the direction in which gas is sent out from the respirator 11 or the opposite direction is positive,
By appropriately setting the comparison voltage, it is possible to convert it into a digital signal such as "1" in the inhalation mode and "0" in the exhalation mode, for example. Since the level of the input signal from the flowmeter 18 varies depending on the connected flowmeter, it is necessary to amplify it and keep it at a constant level. In addition, by adding vibration, the frequency (10~
Since vibrations (approximately 100Hz) are superimposed, prevent malfunctions due to this effect. That is, the respiratory wave component is discriminated by the low-pass wave detector based on the difference in the number of breaths from 8 to 30 times/minute and the vibration frequency. A respiratory wave component of a predetermined level is extracted from the flow rate signal at the terminal 43 by a wave amplifying circuit 44, and further converted into a digital signal of "1" and "0" by a comparator 45. The thus obtained discrimination signal is outputted by the respiratory gas phase discrimination circuit 46 to, for example, "1" in the inhalation mode;
In the exhalation mode, a signal of "0" and its inverted signal are taken out.

On the other hand, the drive circuit 41 is mainly composed of a direct current solid state relay, and its primary side is switched by a mode changeover switch 47. For example, when the switch 47 is set to the exhalation mode, among the output signals of the discrimination circuit 46, a signal of "1" for exhalation and "0" for inspiration is supplied to the drive circuit 41.
Only during the expiration phase, the primary side of the solid state relay is turned ON, and the built-in light emitting diode for exhalation mode indication lights up. As a result, the secondary side of the solid state relay becomes "ON" during the exhalation phase, and while it is "ON", the variable voltage generation circuit 39 is connected to the motor 37, and the motor 37 rotates. During the inspiratory phase, the signal from the respiratory gas phase discrimination circuit 46 is "0", so the solid state relay is in the "OFF" state, and the electrical connection between the variable voltage generating circuit 39 and the motor 37 is cut off. Motor 37 does not operate.

By switching the mode changeover switch 47, in addition to the exhalation mode, an inhalation mode and a continuous mode can be selected. Furthermore, in this example, the dynamic range of the superimposed vibrations can be changed. In order to change the dynamic range, a piston 48 is provided in the cylinder 31 in FIG.
It projects outward from the end plate 51 opposite to the diaphragm 34. The piston shaft 49 has a thread cut on its circumferential surface, and a holding cylinder 5 is rotatably mounted on the outside of the end plate 51.
2 is held, and the piston shaft 49 is screwed into and inserted into a screw formed on the inner peripheral surface of the holding cylinder 52. A gear 53 is attached to mesh with a screw formed on the outer peripheral surface of the holding cylinder 52, a gear 54 is attached to the gear 53, and the gear 54 is attached to the shaft of a motor 55. Dynamic range setting section 57 of control section 56
By selectively controlling the two switches of
6 can be controlled to rotate forward, reverse, and stop. Further, a detection knob 58 is attached to the protruding end of the piston shaft 49, and micro switches 61 and 62 for setting the piston movement range are arranged on the movement of the detection knob 58. A seal ring 63 is interposed between the circumferential surface of the piston 48 and the inner circumferential surface of the cylinder 31.

Due to the movement of the piston 48, the diaphragm 34
By changing the volume of the cylinder 31 between the piston 48 and the piston 48, the dynamic range of the superimposed vibration is changed. The movement of the piston 48 is controlled by the motor 5.
This is done by rotating the holding cylinder 52 by rotating the holding cylinder 52. At the limit of movement of the piston 48 on the diaphragm 34 side, that is, at the dead center, the micro switch 6
When the detection knob 58 presses the lever 1,
Further, the dead point of the piston 48 on the end plate 51 side is detected by the detection knob 58 pushing the lever of the micro switch 62, and this detection output is input to the control unit 56 to cut off the current to the motor 55. Motor 55 is stopped.

In this configuration, gas from the respirator 11 passes through the cylinder 31 from the air supply port 32 and passes through the exhaust port 33.
It exits and is supplied to the lungs 16. That is, cylinder 3
1 constitutes a part of the gas passage, and the cross-sectional area of this gas passage is changed by the vibration of the diaphragm 34, so that the gas in the cylinder is instantaneously compressed or expanded, that is, the pressure is increased. The strength is changed to give vibration to the gas passing through the gas passage. By switching the mode selector switch 47,
When the vibrations are continuously superimposed as shown in FIG. 1C, it is possible to select the case where the vibrations are superimposed only during exhalation or only during inspiration, as shown in FIGS. 1D and E. In this embodiment, by changing the position of the piston 48, the effective volume inside the cylinder 31 is changed, and since the volume change inside the cylinder 31 based on the vibration of the diaphragm 34 is constant, the amplitude of the superimposed vibrations and the breathing The ratio to vibration changes, that is, the dynamic range changes.

As is clear from the above description, the diaphragm 34, vibrator 36, etc. in FIG. 3 constitute vibration imparting means, the wave amplifier 44, comparator 45, and exhalation phase discrimination circuit 46 constitute exhalation/intake discrimination means, The variable voltage generation circuit 39 and the drive circuit 41 constitute a drive means, and the cylinder 31 constitutes a gas chamber.

<Effects> As described above, the vibration adder of the present invention can be added to an artificial respirator to superimpose vibrations on exhaled air, inhaled air, or both. Vibration in the inspiratory mode will increase gas diffusion in the alveolar membrane. That is, gas diffusion generates turbulent flow when considered from Fick's law and Weibel's airway cross-sectional area model, and turbulent diffusion allows gas from the ventilator to reach the lung periphery. The addition of vibration in the inhalation mode generates this turbulent flow and causes the gas to reach the lung periphery through turbulent diffusion. In other words, by applying vibration to the lungs from the gas phase, gas exchange efficiency is increased and gas exchange is promoted for low compliance lung lesions (IRDS: Neonatal Respiratory Distress Syndrome, ARDS: Adult Respiratory Distress Syndrome, etc.), mainly pulmonary edema. can do.

On the other hand, when vibration is added to the exhalation mode, the airway pressure is maintained at positive pressure intermittently, opening the obstructed peripheral airways and eliminating intrapulmonary shunts, that is, blood entering the arterial system without passing through the ventilation area of the lungs. It also has an effect similar to that of PEEP (positive pressure obtained by maintaining positive pressure in the airways even at the end of expiration), which has the effect of stopping alveolar collapse, and has the benefit of reducing venous return obstruction. In other words, the addition of vibration is compensated for by increasing the respiratory rate, thereby reducing the tidal volume and lowering the average airway pressure, making it possible to reduce pressure damage to the lungs and circulation suppression.

By applying vibration to each exhalation and inhalation mode, the effects of each mode can be brought out independently, making it possible to provide treatment tailored to the condition of a patient with respiratory failure. Moreover, it can be easily attached to the intake and exhalation passages of conventional ventilators, and ventilation methods can be adapted to suit the patient's condition. In addition, when used in combination with insufflation therapy, the insufflation efficiency can also be increased.

Further, in the embodiment described above, the vibration frequency and the dynamic range can be adjusted independently. The magnitude of the vibration to be added is preferably about 1/4 of the tidal ventilation amount, and the airway pressure change is preferably about ±3 to 5 cmH ₂ O. Further, it is preferable that the frequency of the additional vibration is changed in accordance with the natural frequency of the patient. The vibration of the diaphragm 34 may be driven electromagnetically without using a motor.

In the above description, the vibration adder of the present invention was added to an artificial respirator, but it may also be added to other respiratory treatment devices. For example, as shown in FIG. 4, treatment may be performed by inhaling humidified gas from a humidifying inhaler (nebulizer) 71 through a gas passage 72 and into the lungs 16 from the joint 15 with the human body. In this case, in the past, the humidifying gas was supplied at a constant flow rate as shown in FIG. 5A, but by inserting the vibration adder 25 into the gas passage 72, the humidifying gas was supplied as shown in FIG. 5B. Gives vibration to the flow rate. This vibration improves the depth of the humidified gas, for example, encourages sputum production and allows for easier breathing. In addition, in FIG. 4, exhaled air is discharged from the connecting portion 15 to the outside.

[Brief explanation of drawings]

FIG. 1 is for explaining the present invention, and is a diagram showing an example of the flow rate in the breathing gas passage, FIG. 2 is a diagram showing an example of application of the vibration adder according to the present invention, and FIG. 3 is a diagram showing an example of the application of the vibration adder according to the present invention. FIG. 4 is a block diagram showing another application example of the vibration applying device of the present invention, and FIG. 5 is a diagram for explaining FIG. 4. 11: Respirator, 12: Intake side gas passage, 1
3: Exhalation side gas passage, 14: Common gas passage, 1
5: Joint, 16: Lung, 17: Flow sensor, 2
5: Vibration adder of this invention, 31: Cylinder, 3
4: Diaphragm, 36: Vibrator, 43: Flowmeter output input terminal, 47: Mode selection switch, 4
8: Piston.

Claims (1)

[Scope of Claims] 1. A gas chamber having an air supply port and an exhaust port and inserted into a gas passage between a respiratory treatment device and a connecting portion with the human body, and a cross-sectional area of the gas passage within the gas chamber. A vibration imparting means that vibrates the gas by periodically changing the air flow rate, and a flow rate signal of the respiratory air output from the flow meter of the respiratory treatment device are inputted, and the expiratory period and the inspiratory period are discriminated, and each period is expiration/intake discrimination means for outputting a signal corresponding to the expiration/intake discrimination means; a mode changeover switch for switching and setting the vibration application period of the vibration application means to either the expiration period or the inhalation period, or both periods; and the expiration/intake discrimination means. and a driving means for driving the vibration applying means according to the switching setting of the mode changeover switch.