An oxygen concentration calibration device and calibration method for a portable oxygen concentrator

Abstract

This invention discloses an oxygen concentration calibration device for a portable oxygen concentrator, comprising: a zirconia oxygen sensor, a signal processing unit, a central processing unit, and a negative pressure generating unit; the central processing unit is connected to the oxygen concentrator's CPU, receives the ultrasonic pulse frequency and the oxygen supply pulse width coefficient, and controls the oxygen concentrator to adjust the oxygen supply pulse width coefficient; the oxygen outlet of the oxygen concentrator is connected to the air inlet of the negative pressure generating unit and the zirconia oxygen sensor respectively through a three-way connector; the central processing unit is used to control the negative pressure generating unit to trigger the portable oxygen concentrator to generate oxygen; the zirconia oxygen sensor outputs the oxygen concentration detection current to the signal processing unit, which converts it into a voltage signal; the central processing unit calculates the oxygen concentration based on the voltage signal, records the ultrasonic pulse frequency and oxygen concentration under different oxygen supply pulse width coefficients, obtains the fitting relationship between the ultrasonic pulse frequency and oxygen concentration using the least squares method, and sends it to the oxygen concentrator's CPU to calibrate the oxygen concentration.

Description

Technical Field

[0001] This invention belongs to the technical field of oxygen concentration calibration for portable oxygen concentrators, and relates to an oxygen concentration calibration device and calibration method for portable oxygen concentrators. Background Technology

[0002] A portable oxygen concentrator is a small, portable oxygen generator that can continuously provide oxygen at a concentration of 90%. For this device to accurately alarm for oxygen concentration, it needs to accurately measure the oxygen concentration. Current portable oxygen concentrators use ultrasonic waves to measure oxygen concentration; however, ultrasonic measurements require calibration due to errors inherent in the manufacturing and assembly of the ultrasonic tube. Therefore, there is an urgent need for an oxygen concentration calibration device and method for portable oxygen concentrators to perform pre-shipment calibration. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention aims to provide an oxygen concentration calibration device and method for a portable oxygen concentrator, which can accurately and quickly calibrate the oxygen concentration of the portable oxygen concentrator.

[0004] The present invention provides an oxygen concentration calibration device for a portable oxygen generator, comprising: a zirconium oxide oxygen sensor, a signal processing unit, a central processing unit, and a negative pressure generating unit connected in sequence.

[0005] The central processing unit is connected to the oxygen generator's CPU, receives the ultrasonic pulse frequency and oxygen supply pulse width coefficient, and sends instructions to control the oxygen generator's CPU to adjust the oxygen supply pulse width coefficient; the oxygen outlet of the oxygen generator is connected to the air inlet of the negative pressure generating unit and the zirconia oxygen sensor respectively through a three-way connector.

[0006] The central processing unit is used to control the negative pressure generating unit to start, thereby triggering the portable oxygen concentrator to produce oxygen; the zirconia oxygen sensor is used to output the oxygen concentration detection current to the signal processing unit; the signal processing unit is used to process the oxygen concentration detection current and convert it into a voltage signal; the central processing unit calculates the corresponding oxygen concentration based on the voltage signal, and records the ultrasonic pulse frequency read by the oxygen concentrator and the calculated oxygen concentration under different oxygen supply pulse width coefficients, and then uses the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and the oxygen concentration and sends it to the oxygen concentrator CPU to calibrate the oxygen concentration.

[0007] In the oxygen concentration calibration device of the portable oxygen concentrator of the present invention, the central processing unit calculates the oxygen concentration according to the following formula:

[0008]

[0009] Where y is the oxygen concentration and u is the voltage signal.

[0010] In the oxygen concentration calibration device of the portable oxygen concentrator of the present invention, the fitting relationship between the ultrasonic pulse frequency data and the oxygen concentration is as follows:

[0011] y = -325.513 + 57.511x - 3.238x 2 +0.0838x 3

[0012] Where y is the oxygen concentration and x is the ultrasonic pulse frequency data.

[0013] In the oxygen concentration calibration device of the portable oxygen concentrator of the present invention, the signal processing unit includes: a zirconia reference voltage circuit, a zirconia sampling circuit, and a -5V reference voltage circuit; the zirconia reference voltage circuit is connected to the signal power supply input terminal of the zirconia oxygen sensor, and is used to generate a 1.6V voltage signal to supply the reference circuit in the zirconia oxygen sensor to generate an oxygen concentration detection current; the zirconia sampling circuit is connected to the signal output terminal of the zirconia oxygen sensor, amplifies the oxygen concentration detection current, and converts it into a voltage signal; the -5V reference voltage circuit is connected to both the zirconia reference voltage circuit and the zirconia sampling circuit, and provides a -5V reference voltage.

[0014] In the oxygen concentration calibration device of the portable oxygen generator of the present invention, the oxygen concentration calibration device is further provided with a power supply circuit for supplying power to the zirconium oxide oxygen sensor, the signal processing unit, the central processing unit and the negative pressure generating unit.

[0015] The present invention provides a method for calibrating the oxygen concentration of a portable oxygen concentrator, comprising:

[0016] Step 1: Before the portable oxygen generator produces oxygen, it first sends the ultrasonic pulse frequency and oxygen supply pulse width coefficient to the central processing unit of the oxygen concentration calibration device.

[0017] Step 2: The central processing unit controls the negative pressure generating unit to trigger the portable oxygen concentrator to generate oxygen at a frequency of 40 times per minute;

[0018] Step 3: The oxygen concentration calibration device measures the oxygen concentration through a zirconia oxygen sensor, outputs an oxygen concentration detection current, and converts it into a voltage signal. The central processing unit then calculates the oxygen concentration. Once the oxygen concentration stabilizes, the central processing unit records the ultrasonic pulse frequency measured by the portable oxygen generator and the calculated oxygen concentration.

[0019] Step 4: The central processing unit controls the oxygen generator CPU to increase the oxygen supply pulse width coefficient, and repeats step 3 to record the ultrasonic pulse frequency and calculated oxygen concentration under different oxygen supply pulse width coefficients until the oxygen concentration reaches the oxygen concentration in the ambient air.

[0020] Step 5: Use the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and the oxygen concentration, and send it to the oxygen generator CPU to calibrate the oxygen concentration.

[0021] In the oxygen concentration calibration method of the portable oxygen concentrator of the present invention, step 1 specifically involves: before oxygen production, the central processing unit communicates with the oxygen concentrator CPU to receive and record the ultrasonic pulse frequency and the oxygen supply pulse width coefficient, and records the oxygen concentration at this time as 20.9%.

[0022] In the oxygen concentration calibration method of the portable oxygen concentrator of the present invention, after the oxygen concentrator CPU receives the fitting relationship in step 5, it adjusts the oxygen supply pulse width coefficient of the portable oxygen concentrator to the initial value, and then the oxygen concentrator CPU calculates the calibrated oxygen concentration according to the fitting relationship and the detected ultrasonic pulse frequency.

[0023] The oxygen concentration calibration device and calibration method for a portable oxygen concentrator of the present invention have the following beneficial effects:

[0024] The oxygen concentration calibration device of this invention has a simple structure, is easy to operate, and can improve calibration efficiency. Existing devices for calibrating the ultrasonic tube of the oxygen concentration detection unit in an oxygen generator require a standard concentration oxygen source, which is typically obtained from an external gas cylinder. The oxygen concentration calibration device of this invention does not use an external gas cylinder, saving energy and reducing costs. The oxygen concentration calibration method of this invention can obtain accurate measurement results within its application range, achieving precise calibration. Attached Figure Description

[0025] Figure 1 This is a structural block diagram of an oxygen concentration calibration device for a portable oxygen generator according to the present invention. Detailed Implementation

[0026] like Figure 1 As shown, an oxygen concentration calibration device for a portable oxygen generator according to the present invention includes: a zirconia oxygen sensor, a signal processing unit, a central processing unit, and a negative pressure generating unit connected in sequence.

[0027] The central processing unit is connected to the oxygen generator's CPU, receives the ultrasonic pulse frequency and oxygen supply pulse width coefficient, and sends instructions to control the oxygen generator's CPU to adjust the oxygen supply pulse width coefficient; the oxygen outlet of the oxygen generator is connected to the air inlet of the negative pressure generating unit and the zirconia oxygen sensor respectively through a three-way connector.

[0028] The central processing unit is used to control the negative pressure generating unit to start, thereby triggering the portable oxygen concentrator to produce oxygen; the zirconia oxygen sensor is used to output the oxygen concentration detection current to the signal processing unit; the signal processing unit is used to process the oxygen concentration detection current and convert it into a voltage signal; the central processing unit calculates the corresponding oxygen concentration based on the voltage signal, and records the ultrasonic pulse frequency read by the oxygen concentrator and the calculated oxygen concentration under different oxygen supply pulse width coefficients, and then uses the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and the oxygen concentration and sends it to the oxygen concentrator CPU to calibrate the oxygen concentration.

[0029] The signal processing unit includes: a zirconia reference voltage circuit, a zirconia sampling circuit, and a -5V reference voltage circuit; the zirconia reference voltage circuit is connected to the signal power input terminal of the zirconia oxygen sensor and is used to generate a 1.6V voltage signal to supply the reference circuit in the zirconia oxygen sensor to generate an oxygen concentration detection current; the zirconia sampling circuit is connected to the signal output terminal of the zirconia oxygen sensor, amplifies the oxygen concentration detection current, and converts it into a voltage signal; the -5V reference voltage circuit is connected to both the zirconia reference voltage circuit and the zirconia sampling circuit, providing a -5V reference voltage.

[0030] The negative pressure generating unit includes a fan and an air collecting shroud. The fan is located inside the air collecting shroud, which has an air duct. The air duct outlet has a connecting pipe, and the negative pressure generating unit is connected to a T-joint through the connecting pipe.

[0031] In practice, the central processing unit calculates the oxygen concentration according to the following formula:

[0032]

[0033] Where y is the oxygen concentration and u is the voltage signal.

[0034] In specific implementation, the fitting formula between the ultrasonic pulse frequency data and the oxygen concentration is as follows:

[0035] y = -325.513 + 57.511x - 3.238x 2 +0.0838x 3

[0036] Where y is the oxygen concentration and x is the ultrasonic pulse frequency data.

[0037] In practice, the oxygen concentration calibration device is also equipped with a power supply circuit that supplies power to the zirconium oxide oxygen sensor, signal processing unit, central processing unit and negative pressure generation unit.

[0038] The present invention also provides a method for concentration calibration using the above-mentioned oxygen concentration calibration device, specifically including the following steps:

[0039] Step 1: Before the portable oxygen generator produces oxygen, it first sends the ultrasonic pulse frequency and oxygen supply pulse width coefficient to the central processing unit of the oxygen concentration calibration device.

[0040] Step 1 specifically involves the following steps: Before oxygen production, the central processing unit communicates with the oxygen generator CPU to receive and record the ultrasonic pulse frequency and oxygen supply pulse width coefficient, and records the oxygen concentration at this time as 20.9%. The central processing unit and the oxygen generator CPU can communicate via SPI / I2C or serial port.

[0041] Step 2: The central processing unit controls the negative pressure generating unit to trigger the portable oxygen concentrator to generate oxygen at a frequency of 40 times per minute;

[0042] This frequency is the maximum oxygen supply frequency of the portable oxygen concentrator. The more times it is used, the closer it is to continuous oxygen supply on a macroscopic scale, and the more accurate the oxygen concentration produced and measured will be.

[0043] Step 3: The oxygen concentration calibration device measures the oxygen concentration through a zirconia oxygen sensor, outputs an oxygen concentration detection current, and converts it into a voltage signal. The central processing unit then calculates the oxygen concentration. Once the oxygen concentration stabilizes, the central processing unit records the ultrasonic pulse frequency measured by the portable oxygen generator and the calculated oxygen concentration.

[0044] The ultrasonic pulse frequency is used to measure the internal concentration of oxygen in the portable oxygen concentrator. It is detected by the oxygen concentration detection unit within the concentrator using ultrasound. The oxygen pulse width coefficient is used to manage the oxygen pulse supply time of the portable oxygen concentrator. It is obtained through specific experiments, and due to minor structural errors, the value of the oxygen pulse width coefficient varies among portable oxygen concentrators. It ultimately determines the oxygen concentration produced by the portable oxygen concentrator.

[0045] Step 4: The central processing unit controls the oxygen concentrator's CPU to increase the oxygen supply pulse width coefficient, repeating step 3 to record the ultrasonic pulse frequency and calculated oxygen concentration under different oxygen supply pulse width coefficients, until the oxygen concentration reaches the ambient air oxygen concentration. The portable oxygen concentrator's concentration alarm value is 82%, and the applicable concentration range is 35%-96%.

[0046] Step 5: Use the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and the oxygen concentration, and send it to the oxygen generator CPU to calibrate the oxygen concentration.

[0047] In the oxygen concentration calibration method of the portable oxygen concentrator of the present invention, after the oxygen concentrator CPU receives the fitting relationship in step 5, it adjusts the oxygen supply pulse width coefficient of the portable oxygen concentrator to the initial value, and then the oxygen concentrator CPU calculates the calibrated oxygen concentration according to the fitting relationship and the detected ultrasonic pulse frequency.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the ideas of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An oxygen concentration calibration device for a portable oxygen concentrator, characterized in that, include: The zirconium oxide oxygen sensor, signal processing unit, central processing unit, and negative pressure generation unit are connected in sequence. The central processing unit is connected to the oxygen generator's CPU, receives the ultrasonic pulse frequency and oxygen supply pulse width coefficient, and sends instructions to control the oxygen generator's CPU to adjust the oxygen supply pulse width coefficient; the oxygen outlet of the oxygen generator is connected to the air inlet of the negative pressure generating unit and the zirconia oxygen sensor respectively through a three-way connector. The central processing unit controls the negative pressure generating unit to start, thereby triggering the portable oxygen concentrator to generate oxygen; the zirconia oxygen sensor outputs the oxygen concentration detection current to the signal processing unit; the signal processing unit processes the oxygen concentration detection current and converts it into a voltage signal; the central processing unit calculates the corresponding oxygen concentration based on the voltage signal, records the ultrasonic pulse frequency read by the oxygen concentrator and the calculated oxygen concentration under different oxygen supply pulse width coefficients, and then uses the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and the oxygen concentration and sends it to the oxygen concentrator CPU to calibrate the oxygen concentration. The central processing unit calculates the oxygen concentration according to the following formula: Where y is the oxygen concentration and u is the voltage signal; The fitting formula between the ultrasonic pulse frequency data and the oxygen concentration is as follows: y=-325.513+57.511x-3.238x 2 +0.0838x 3 Where y is the oxygen concentration and x is the ultrasonic pulse frequency data; The signal processing unit includes: a zirconia reference voltage circuit, a zirconia sampling circuit, and a -5V reference voltage circuit; the zirconia reference voltage circuit is connected to the signal power input terminal of the zirconia oxygen sensor and is used to generate a 1.6V voltage signal to supply the reference circuit in the zirconia oxygen sensor to generate an oxygen concentration detection current; the zirconia sampling circuit is connected to the signal output terminal of the zirconia oxygen sensor, amplifies the oxygen concentration detection current, and converts it into a voltage signal; the -5V reference voltage circuit is connected to both the zirconia reference voltage circuit and the zirconia sampling circuit, providing a -5V reference voltage.

2. The oxygen concentration calibration device for a portable oxygen concentrator as described in claim 1, characterized in that, The oxygen concentration calibration device is also equipped with a power supply circuit for supplying power to the zirconia oxygen sensor, signal processing unit, central processing unit and negative pressure generation unit.

3. A method for calibrating the oxygen concentration of a portable oxygen concentrator, characterized in that, include: Step 1: Before the portable oxygen generator produces oxygen, it first sends the ultrasonic pulse frequency and oxygen supply pulse width coefficient to the central processing unit of the oxygen concentration calibration device. Before oxygen production, the central processing unit communicates with the oxygen generator CPU to receive and record the ultrasonic pulse frequency and oxygen supply pulse width coefficient, and records the oxygen concentration at this time as 20.9%. Step 2: The central processing unit controls the negative pressure generating unit to trigger the portable oxygen concentrator to generate oxygen at a frequency of 40 times per minute; Step 3: The oxygen concentration calibration device measures the oxygen concentration through a zirconia oxygen sensor, outputs an oxygen concentration detection current, and converts it into a voltage signal. The central processing unit then calculates the oxygen concentration. Once the oxygen concentration stabilizes, the central processing unit records the ultrasonic pulse frequency measured by the portable oxygen generator and the calculated oxygen concentration. Step 4: The central processing unit controls the oxygen generator CPU to increase the oxygen supply pulse width coefficient, and repeats step 3 to record the ultrasonic pulse frequency and calculated oxygen concentration under different oxygen supply pulse width coefficients until the oxygen concentration reaches the oxygen concentration in the ambient air. Step 5: Use the least squares method to obtain the fitting relationship between the ultrasonic pulse frequency and oxygen concentration and send it to the oxygen generator CPU to calibrate the oxygen concentration. The oxygen pulse width coefficient of the portable oxygen concentrator is adjusted to the initial value, and then the oxygen concentrator CPU calculates the calibrated oxygen concentration based on the fitted relationship and the detected ultrasonic pulse frequency.

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