JP3655792B2 - Breathing oxygen delivery system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a breathing gas supply device including an automatic opening / closing jig that can be operated according to a breathing cycle of a user. More specifically, it is a medical device that is used when patients with chronic respiratory disease perform oxygen inhalation therapy, and supplies oxygen or oxygen-enriched gas as a breathing gas intermittently to the user according to the respiratory cycle. The present invention relates to a respiratory synchronized oxygen supply device.
[0002]
[Prior art]
One of the most effective treatments for respiratory diseases such as emphysema and chronic bronchitis is oxygen inhalation therapy. In recent years, oxygen-enriched air supply devices or oxygen cylinders have been used for this therapy. It has become. When the inhalation therapy is performed at a hospital or at home, an oxygen-enriched air supply device using a pressure fluctuation adsorption type, a membrane type, or a solid electrolyte membrane that selectively permeates oxygen, or a large-capacity fixed oxygen cylinder. Is used.
[0003]
On the other hand, when a patient goes out to the hospital, a portable oxygen cylinder is used. Since this is a cylinder carried by a patient with a respiratory disease, it needs to be small and light, and is filled with high-pressure oxygen gas so as to extend the use time as the outing time is extended. In addition, in order to further extend the time that the patient can use, a so-called demand regulator that incorporates a respiration sensor and an automatic open / close valve inside, supplies oxygen only during the patient's inspiration time, and stops supply during the expiration time is used Thus, means for saving oxygen are used.
[0004]
[Problems to be solved by the invention]
As described above, a patient with a respiratory disease carries an oxygen cylinder equipped with a demand regulator when going to the hospital or going out, and uses oxygen-enriched air by inhalation. Most of the oxygen supply amount control methods using such a demand regulator are a supply amount (pulse amount) fixed type and an I / E ratio (ratio of inspiratory time to expiratory time) fixed type.
[0005]
Generally, the average respiration I / E ratio for humans is 1: 2, and during work (tachypnea) this ratio is generally close to 1: 1, and the supply is the I / E If the ratio is not changed in real time, the patient's oxygen requirement will be excessive or insufficient, causing problems such as difficulty in breathing the patient and shortening the usable time of the cylinder.
[0006]
[Means for Solving the Problems]
As a result of earnestly examining the problem, the present inventor is able to increase the supply amount in real time and supply an appropriate amount when the respiratory cycle becomes short in the respiratory synchronized oxygen supply device capable of detecting (calculating) the respiratory cycle. It has been found that this problem can be solved.
[0007]
That is, the present invention comprises an oxygen cylinder, a flow rate setting means, an automatic opening / closing valve means, a detection means for detecting the breathing of the user, and a control means for controlling the opening / closing of the automatic opening / closing valve means based on the detection result. In the breath-synchronized oxygen supply device that supplies oxygen to the cannula in synchronization with the respiration, the control means controls the oxygen supply amount so as to increase the supply amount in real time during tachypnea A respiratory-synchronized oxygen supply device is provided.
[0008]
In the present invention, the control means includes means for calculating a respiration cycle based on the detection result, and when the calculated respiration cycle becomes shorter than the set respiration cycle, the automatic opening / closing is performed to increase the oxygen supply amount. A breath-synchronized oxygen supply device is provided that controls the opening and closing of the valve means.
[0009]
Further, according to the present invention, the respiratory tuned oxygen supply device includes a prescription flow rate input unit, a set respiration cycle, and a reference pulse amount setting unit based on an I / E ratio, and the control unit has a calculated respiration cycle as a set respiration cycle. A breath-synchronized oxygen supply device is provided for controlling the opening / closing of the automatic opening / closing valve means so as to increase the oxygen supply amount that is a constant multiple of the reference pulse amount when the threshold value is shorter than the predetermined threshold value. In particular, it is an object of the present invention to provide a respiratory tuned oxygen supply device characterized in that the reference pulse amount is a pulse amount having a set respiration cycle of 3 seconds and a 1 / E ratio of 1: 2.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The respiratory tuned oxygen supply device of the present invention is a device that can set an oxygen supply amount and a supply timing according to an oxygen supply amount to be used for a patient determined by, for example, a doctor's prescription. The respiratory tuned oxygen supply device is characterized in that a supply amount is increased in real time and an appropriate amount is supplied.
[0011]
FIG. 1 shows an example of a preferred embodiment of the respiratory tuned oxygen supply device of the present invention. Such an apparatus has a pressurized oxygen cylinder 1 and one end communicating with the cylinder 1, the other end having the oxygen open-type supply means 7, and a conduit means 5 having an automatic flow path opening / closing means 3 in the middle, A breathing gas supply device comprising a demand regulator means 10 for controlling the supply amount of oxygen by controlling the opening / closing time of the automatic flow path opening / closing means.
[0012]
In the method of demand regulator control, in the case of a method of supplying an oxygen amount assuming that the I / E ratio is always 1: 2 by calculating the respiratory cycle, the I / E ratio at the time of work (at the time of tachypnea) is generally 1 Since the supply amount is not changed in real time according to its I / E ratio, excess or deficiency occurs with respect to the required amount, resulting in difficulty in breathing of the patient and shortening of the cylinder usable time. In the apparatus of the present invention, in a respiratory synchronized oxygen supply apparatus capable of detecting (calculating) a respiratory cycle, when the respiratory cycle becomes shorter, the supply amount is increased in real time and an appropriate amount is supplied.
[0013]
The solenoid valve used in the apparatus of the present invention is not particularly limited, but a structure in which the valve is closed by a spring when the power is turned off prevents battery consumption and prevents inflow of dust into the apparatus when the power is stopped. It is preferable in that it can be done.
[0014]
As a means for detecting respiration used in the device of the present invention, a method for detecting a temperature difference of inspiratory expiration and a sensor for detecting expansion and contraction in a band wound around the chest and converting it into an electrical signal are provided. There are known a method for detecting the movement of a gas (Respiet graph), a flow rate detection method for detecting a change in gas flow and pressure by inspiration and expiration. More simply, the respiratory phase change can be detected by detecting the gas pressure at the end of the conduit.
[0015]
As a pressure measuring sensor used for such a detecting means, a pressure transducer such as a capacitance type pressure transducer, a differential transformer, a strain gauge type inductance conversion, an electric resistance conversion method or the like can be used. In particular, it is preferable to use a semiconductor pressure sensor.
[0016]
Accordingly, in the apparatus of the present invention, the conduit 5 is provided with a breathing phase detecting means 9 having a function capable of detecting at least a part of a predetermined phase, and a control means 10 for controlling the demand valve 3 which is an automatic opening / closing valve. Have. The control means uses the measured respiratory cycle to determine the respiratory state according to the following determination formula 1.
[Judgment formula 1]
Normal breathing: measured breathing cycle ≤ Ra (weak tachypnea threshold)
Tidal breathing: Ra <measured respiratory cycle ≤ Rb (tachycardia threshold)
Tachypnea: Rb <measured respiratory cycle [0017]
That is, normal breathing refers to a state in which the measured respiratory cycle is within a range in which a certain threshold is added to the set respiratory cycle. In the present apparatus, since control is performed when tachypnea occurs, it means a state where the measured breathing cycle is equal to or lower than the upper limit threshold (weak tachypnea threshold: Ra) of the set breathing cycle. It is preferable to input a user's normal average respiratory cycle as the set respiratory cycle. Further, the Ra value that is a threshold value is a variable value that can be changed by the user. For example, assuming that the set respiratory cycle is 20 BPM (respiration rate per minute) = 3 seconds, Ra = 30 BPM (= 2 seconds). When the respiratory cycle is shorter than 2 seconds, it is determined that the state is a tachypnea state.
[0018]
Similarly, a state in which tachypnea is strong is set using the tachypnea threshold Rb, for example, Rb = 40 BPM (= 1.5 seconds), and the range of the measured respiratory cycle from Ra to Rb is a weak tachypnea state, and Rb or more is strong. A tachypnea state and a state can also be judged in steps.
[0019]
Next, the control means performs control to calculate the oxygen supply pulse amount based on the following control expression 1 and increase the supply oxygen flow rate based on the determination result of the respiratory state.
[Control formula 1]
Reference pulse amount: Ls (= Set prescription flow rate x 1/3 x 1/20)
Pulse amount during normal breathing: Ls
Pulse amount during tachypnea: La = Ls × a
Pulse amount during tachypnea: Lb = Ls × b
a and b are constants [0020]
For example, if the doctor's prescription flow rate for the patient is 3 L / min, and the set respiratory cycle is 20 BPM and the I / E ratio is 1: 2,
Reference pulse amount (Ls) = 3 (L / min) x 1/3 x 1/20 = 0.05 (L / pulse)
It becomes. Then, as shown in FIG. 3, when the reference pulse amount is set as a normal pulse amount, and it is determined that the state of tachypnea is based on the determination formula 1, the amount is Ls × a times, for example, a = 1.5. In this case, a pulse amount (= La) of 0.075 (L / pulse) is supplied. If it is determined that the state is a tachypnea state, a pulse amount (= Lb) of 0.1 (L / pulse) is supplied when Ls × b times the amount, for example, b = 2.0. The increment of the pulse amount can be controlled by extending the opening time of the automatic opening / closing valve.
[0021]
A preferred embodiment of the respiratory gas supply apparatus of the present invention will be further described with reference to FIG. 2 with respect to detection means, input means, calculation means, and result display means.
[0022]
Oxygen emitted from the oxygen cylinder 1 which is a breathing gas generating means passes through a pressure reducing valve 101 and a pressure regulating valve 102, and is supplied to a conduit means 5 having a maximum flow rate setting device 31 and an automatic flow path opening / closing (valve) means 3. It is discharged from the nasal cannula 7 which is an open type supply means.
[0023]
The maximum flow rate setting device may be a flow meter such as a normal rotor meter, and has a flow restricting function portion such as a plurality of orifices having openings of different sizes, and its flow restricting function. You may use the flow volume setting means which sets a flow volume by switching a part.
[0024]
Further, the breathing phase detection means 9 provided with a diaphragm type micro pressure fluctuation sensor provided at a branch from the conduit means 5 converts the pressure fluctuation in the breathing into a fluctuation in capacitance, and the conversion circuit 12 in the control means 10 converts the pressure fluctuation. The change in electrostatic capacitance is converted into an electric pulse signal, and the count circuit 14 converts the electric pulse signal into a signal having the number of pulses per unit time (for example, 10 msec).
[0025]
The pulse number signal output from the count circuit 14 is preferably smoothed by the smoothing circuit 16 to reduce noise. This is simply achieved by a moving average operation in which the current data and the past several times, for example, three times of data are integrated to obtain an average of the four data.
[0026]
Using the digital signal obtained in this way, the intake start point detection means 18 in the CPU 11 such as a microcomputer calculates a fluctuation amount, that is, a differential value of the digital signal with respect to time, and the value is larger than a predetermined value. Detected as a breathing start point. The predetermined value is set by the respiration detection sensitivity setting value storage unit and is preferably set by input from an external input means.
[0027]
The period of the respiratory detection start point obtained from the above results is measured, and the respiratory cycle time is calculated. The calculation unit 25 performs a comparison between the calculated respiratory cycle time and two predetermined values, and controls the opening time of the solenoid valve to supply a preset pulse flow rate according to the comparison result. There is a breath tuned oxygenator. The predetermined value is set by the respiratory cycle time storage unit.
[0028]
【The invention's effect】
According to the present invention, by changing the I / E ratio in real time from the breathing cycle and feeding the necessary amount, it is possible to prevent excessive or insufficient filling, and to prevent the patient from having difficulty breathing and shortening the usable time of the cylinder. it can.
[Brief description of the drawings]
FIG. 1 is a schematic flowchart schematically showing a preferred embodiment of a respiratory synchronization oxygen supply apparatus of the present invention.
FIG. 2 is a schematic flowchart schematically showing a preferred embodiment of the respiratory synchronization oxygen supply apparatus of the present invention.
FIG. 3 is a graph of the relationship between the pulse amount (valve opening time) and the breathing time of the breathing synchronized oxygen supply device of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Oxygen cylinder 3 Demand valve 5 Extension tube 7 Nasal cannula 8 Microcomputer 9 Respiration detector 10 Control means 12 Conversion circuit 14 Count circuit 16 Inhalation start detector 18 Respiration cycle calculation part 20 Electromagnetic valve control part 25 Calculation means 31 Flow rate setting device 45 Display means 101 Cylinder original valve 102 Pressure control valve

Claims (2)

An oxygen cylinder, a flow rate setting means, an automatic opening / closing valve means, a detection means for detecting the user's breathing, and a control means for controlling the opening / closing of the automatic opening / closing valve means based on the detection result are synchronized with the user's breathing. In the respiratory tuned oxygen supply device for supplying oxygen to the cannula, the apparatus includes a prescription flow rate input means, a set respiratory cycle, and a reference pulse amount setting means based on the I / E ratio, and the control means is based on the detection result. A means for calculating the breathing cycle is provided, and when the calculated breathing cycle becomes shorter than a predetermined threshold of the set breathing cycle, the opening / closing of the automatic opening / closing valve means is controlled so as to increase the oxygen supply amount that is a constant multiple of the reference pulse amount. A breathing synchronized oxygen supply device, characterized in that: The reference pulse amount, sets the breathing cycle 3 seconds, 1 / E ratio of 1: 2 breathing tuning oxygen supply apparatus according to claim 1, characterized in that the pulse volume.

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