High-precision wide-range expiration detection device and method
By controlling the mixing of exhaled breath samples with zero-point air through a three-way valve and dynamically adjusting the opening and closing of the three-way valve, the problem of signal overflow in traditional exhaled breath detection devices at high concentrations is solved, achieving high-precision wide-range exhaled breath detection and simplifying the algorithm and calibration process.
Patent Information
- Application Number
- CN202511793722.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-03-03
AI Technical Summary
Existing breath detection devices struggle to achieve continuous, accurate, high-precision, wide-range detection across the entire measurement range without increasing sensor hardware complexity, while maintaining high resolution at low concentrations and avoiding signal overflow at high concentrations.
A three-way valve is used to control the mixing of exhaled breath samples with filtered zero-point gas before they enter the electrochemical sensor. By dynamically adjusting the opening and closing of the three-way valve and combining the ratio of the output signal to the saturation signal, the gas concentration is calculated, enabling the detection of signals within the same linear range.
It achieves high-precision detection at low concentrations while avoiding signal overflow at high concentrations, simplifies the algorithm and calibration process, improves test accuracy and simplifies operation.
Smart Images
Figure CN121595850A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of breath detection technology, and more specifically to a high-precision, wide-range breath detection device and method. Background Technology
[0002] Exhaled breath analyzers (hereinafter referred to as breath detectors) are widely used in routine diagnostic tests in hospitals of all levels both domestically and internationally. Different clinical applications require different detection ranges. For example, in exhaled NO testing, according to relevant international standards, the cutoff point for small airway inflammation is 5 ppb, for large airway inflammation it is 25-50 ppb, and for upper airway inflammation it is 250-500 ppb. Therefore, NO breath analyzers typically require an accuracy of ±3 ppb at low concentrations, with a range of 0-3000 ppb, meaning high accuracy at low concentrations and a wide measurement range are required. For CO testing and erythrocyte lifetime determination, high measurement accuracy is required, with CO accuracy requiring at least 0.5 ppm. Statistics show that the exhaled CO concentration of healthy smokers is 17.13 ± 8.5 ppm, that of healthy non-smokers is 3.61 ± 2.15 ppm, and that of passive smokers is 5.20 ± 3.38 ppm. For CO poisoning diagnosis, a CO result of 250 ppm is required. Therefore, CO breath analyzers typically require an accuracy of ±0.5 ppm at low concentrations, with a measurement range of 0-250 ppm. This means that they need both high accuracy at low concentrations and a wide measurement range.
[0003] Electrochemical sensors are commonly used in breath detectors. The microcurrent output by the sensor is amplified and conditioned before being sampled by an analog-to-digital converter. To obtain sufficient resolution in the low-concentration range, a high gain is usually required. However, as the concentration of the gas being measured increases, the amplified signal increases rapidly, easily exceeding the linear operating range of subsequent circuits or converters, causing distortion or even complete failure in the high-concentration range. The traditional "fixed gain, single range" architecture therefore has to make trade-offs between "low-concentration accuracy" and "high-concentration range," making it difficult to simultaneously meet the dual clinical requirements for high accuracy and wide range in expiratory breath testing.
[0004] Patent CN114235909A discloses a method for implementing a breathalyzer with dynamically adjustable range. This method connects a breath sampling module, an alcohol concentration sensor module, a signal processing module, and a dynamic range adjustment module to dynamically adjust the range, automatically switching between different speeds and signal amplification gain based on gas concentration to adapt to measurements of different concentrations. However, this implementation involves a complex sensor circuit design, increasing hardware costs and control complexity. Furthermore, it requires sensitivity calibration for each range, increasing the workload and difficulty of instrument adjustment.
[0005] Therefore, how to provide a high-precision, wide-range breath detection device and method that can maintain high resolution at low concentrations and avoid signal overflow at high concentrations without increasing the complexity of sensor hardware, thereby achieving continuous and accurate breath detection across the entire range, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] In view of this, the present invention provides a high-precision, wide-range exhalation detection device and method.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: A high-precision, wide-range exhalation detection device includes: an exhalation sampling unit, a gas analysis unit, and a control and calculation unit; Exhalation sampling unit, used to collect exhalation samples; The gas analysis unit consists of a three-way valve, an analysis pump, an electrochemical sensor module, and a filter. Both the breath sampling unit and the gas analysis unit are connected to the control and computing unit; The control and calculation unit is used to control the three-way valve to close when the ratio of the output signal to the saturation signal is less than a preset threshold, so that the exhaled breath sample is drawn into the electrochemical sensor module by the analysis pump. When the ratio of the output signal to the saturation signal is greater than the preset threshold, it controls the three-way valve to rapidly switch between closing and opening based on the real-time output signal magnitude, so that the exhaled breath sample is mixed with the zero-point gas filtered by the filter before entering the electrochemical sensor module. The unit calculates the gas concentration in the exhaled breath sample based on the output signal, sensitivity, and the proportion of the three-way valve's closing time. The output signal is the signal sampled by the analog-to-digital converter after the micro-current output by the electrochemical sensor module is conditioned by the amplification link; the saturation signal is the maximum signal value that maintains the linear operation of subsequent circuits, including the amplification link and the analog-to-digital converter.
[0008] Optionally, the exhalation sampling unit consists of a buffer chamber and a two-way valve connected in series, and a pressure sensor is connected in the air path; Buffer chamber, used to collect, store and stabilize exhaled breath samples; Pressure sensors are used to detect pressure changes in the airway and buffer chamber and feed them back to the control and computing unit to ensure that the exhaled breath samples in the buffer chamber are sufficient and stable. A two-way valve is used to control the opening and closing of the buffer chamber so that exhaled breath samples can enter the gas analysis unit.
[0009] Optionally, the electrochemical sensor module is a single electrochemical sensor.
[0010] Optionally, the electrochemical sensor module is a module composed of multiple electrochemical sensors.
[0011] Optionally, the gas concentration in the exhaled breath sample can be calculated based on the output signal, sensitivity, and the proportion of the three-way valve closing time, as follows:
[0012] in, The concentration of the gas being measured; For output signal; Sensitivity; This represents the percentage of the three-way valve's closing time.
[0013] The present invention also provides a high-precision, wide-range breath detection method utilizing a high-precision, wide-range breath detection device, comprising: Step 1: Control the exhaled breath sample to enter the gas analysis unit; Step 2: When the ratio of the output signal to the saturation signal is less than a preset threshold, the three-way valve is closed to allow the exhaled breath sample to be drawn into the electrochemical sensor module via the analysis pump. When the ratio of the output signal to the saturation signal is greater than the preset threshold, the three-way valve is rapidly switched between closing and opening based on the real-time output signal magnitude to ensure that the exhaled breath sample is mixed with the zero-point gas filtered by the filter before entering the electrochemical sensor module. The output signal is the signal sampled by the analog-to-digital converter after the micro-current output by the electrochemical sensor module is conditioned by the amplification link. The saturation signal is the maximum signal value that maintains the linear operation of subsequent circuits, including the amplification link and the analog-to-digital converter. Step 3: Calculate the gas concentration in the exhaled sample based on the output signal, sensitivity, and the proportion of the three-way valve closing time.
[0014] As can be seen from the above technical solution, compared with the prior art, this invention discloses a high-precision, wide-range breath detection device and method. By dynamically adjusting the opening and closing of the three-way valve according to the ratio of the output signal to the saturation signal, while ensuring the accuracy of low-concentration detection through the gain design of the breath detection device, it ensures that during high-concentration detection, the breath sample is mixed with zero-point gas filtered by the filter before entering the electrochemical sensor module, thereby reducing the gas concentration. Finally, the gas concentration in the breath sample is calculated based on the output signal, sensitivity, and the proportion of the three-way valve closing time, thus meeting the clinical requirements for both high precision and wide range in breath detection.
[0015] In addition, for situations where the sensor response signal is nonlinear with concentration, requiring piecewise algorithms and multi-point calibration, the method of this invention can be used to dilute high-concentration sample gas to low concentration, so that the test signal results of high and low concentrations can be within the same linear range. This simplifies the algorithm and calibration process, improves the accuracy of the test, and simplifies the calibration operation. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the device structure provided by the present invention.
[0018] Figure 2 This is a schematic diagram of the NO signal detection results provided by the present invention.
[0019] Figure 3 This is a schematic diagram of the H2 signal detection results provided by the present invention.
[0020] In the diagram, the components are: exhalation sampling unit-100, two-way valve-102, buffer chamber-103, pressure sensor-104, gas analysis unit-200, three-way valve-201, analysis pump-202, electrochemical sensor module-203, filter-204, and control and calculation unit-300. Detailed Implementation
[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0022] Example 1: Embodiment 1 of the present invention discloses a high-precision, wide-range exhalation detection device, such as... Figure 1 As shown, it includes: an exhalation sampling unit 100, a gas analysis unit 200, and a control and calculation unit 300.
[0023] The exhalation sampling unit 100 is used to collect exhalation samples.
[0024] The exhalation sampling unit 100 consists of a buffer chamber 103 and a two-way valve 102 connected in series, and a pressure sensor 104 is connected in the air path; Buffer chamber 103 is used to collect, store, and stabilize exhaled breath samples; Pressure sensor 104 is used to detect pressure changes in the airway and buffer chamber 103 and feed them back to control and calculation unit 300 to ensure that the exhaled breath sample in buffer chamber 103 is sufficient and stable. A two-way valve 102 is used to control the opening and closing of the buffer chamber 103 so that the exhaled breath sample can enter the gas analysis unit 200.
[0025] The gas analysis unit 200 consists of a three-way valve 201, an analysis pump 202, an electrochemical sensor module 203, and a filter 204.
[0026] Both the exhalation sampling unit 100 and the gas analysis unit 200 are connected to the control and calculation unit 300.
[0027] The control and calculation unit 300 is used to control the three-way valve 201 to close when the ratio of the output signal to the saturation signal is less than a preset threshold (the detected gas is a low-concentration gas). The three-way valve 201 is closed only when the ratio is less than a preset threshold (the proportion of time the three-way valve 201 is closed is 1), allowing the exhaled gas sample to be drawn into the electrochemical sensor module 203 via the analysis pump 202. When the ratio of the output signal to the saturation signal is greater than a preset threshold (the detected gas is a high-concentration gas), the unit controls the three-way valve 201 to rapidly switch between closing and opening based on the real-time output signal magnitude (the switching time of the three-way valve can be less than 1ms), so that the exhaled gas sample mixes with the zero-point gas filtered by the filter 204 before entering the electrochemical sensor module 203. The unit calculates the gas concentration in the exhaled gas sample based on the output signal, sensitivity, and the proportion of time the three-way valve 201 is closed. The output signal is the signal sampled by the analog-to-digital converter after the micro-current output by the electrochemical sensor module 203 is conditioned by the amplification link. The saturation signal is the maximum signal value that maintains linear operation of the subsequent circuits, including the amplification link and the analog-to-digital converter.
[0028] The electrochemical sensor module 203 can be a single electrochemical sensor, such as a nitric oxide electrochemical sensor, a carbon monoxide electrochemical sensor, or a hydrogen sulfide electrochemical sensor, or it can be a module composed of multiple electrochemical sensors. The response time of electrochemical sensors is typically from a few seconds to tens of seconds.
[0029] Based on the output signal, sensitivity, and the proportion of the closing time of the three-way valve 201, the gas concentration in the exhaled sample is calculated as follows:
[0030] in, The concentration of the gas being measured; For output signal; Sensitivity is the magnitude of the change in the sensor's output signal (such as current or voltage) for every unit change in gas concentration. This represents the percentage of the time that the three-way valve 201 is closed (if the three-way valve 201 is always closed, this percentage is 1).
[0031] like Figure 2The figure shows the signal detection results of NO according to this invention. The response time T90 of the nitric oxide electrochemical sensor is about 10s. The test process is to first test the zero-point gas for 15s and then switch to test the NO sample gas. When testing NO gas from 15ppb to 1000ppb, the ratio of the output signal to the saturation signal is less than the preset threshold of 90% within 25s. During the entire test process, the three-way valve 201 is closed, and the Q value is 1. When testing 3000ppb NO gas, the output signal reaches the point where the ratio of the output signal to the saturation signal is less than the preset threshold of 90% at 18s. According to the preset control unit adjustment algorithm Q = (18-15), the output signal is adjusted accordingly. 0.1 + 0.1 = 0.4, the three-way valve is set to close in 0.4ms and open in 0.6ms.
[0032] like Figure 3 The image shows the signal detection results for H2 according to this invention. The response time T90 of the hydrogen electrochemical sensor is approximately 20 seconds, and the test process involves directly testing the sample gas for 30 seconds. When testing H2 gas from 10 ppm to 80 ppm, the ratio of the output signal to the saturation signal is less than the preset threshold of 60% within 15 seconds. During the entire test process, the three-way valve 201 is closed, and the Q value is 1. However, when testing 200 ppm H2 gas, the output signal reaches the point where the ratio of the output signal to the saturation signal is less than the preset threshold of 60% within 6 seconds. According to the preset control unit adjustment algorithm, Q=6. 0.05 + 0.2 = 0.5, the three-way valve is set to close in 0.5ms and open in 0.5ms.
[0033] Example 2: Embodiment 2 of the present invention discloses a high-precision, wide-range exhalation detection method using a high-precision, wide-range exhalation detection device, comprising: Step 1: Control the exhaled breath sample to enter the gas analysis unit 200; Step 2: When the ratio of the output signal to the saturation signal is less than a preset threshold, the three-way valve 201 is closed, allowing the exhaled breath sample to be drawn into the electrochemical sensor module 203 via the analysis pump 202. When the ratio of the output signal to the saturation signal is greater than a preset threshold, the three-way valve 201 is controlled to rapidly switch between closing and opening based on the real-time output signal magnitude, so that the exhaled breath sample is mixed with the zero-point gas filtered by the filter 204 before entering the electrochemical sensor module 203; wherein, the output signal is the signal sampled by the analog-to-digital converter after the microcurrent output by the electrochemical sensor module 203 is conditioned by the amplification link; the saturation signal is the maximum signal value that the subsequent circuits, including the amplification link and the analog-to-digital converter, maintain a linear operating state; Step 3: Calculate the gas concentration in the exhaled sample based on the output signal, sensitivity, and the proportion of the closing time of the three-way valve 201.
[0034] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A high-precision, wide-range breath detection device, characterized in that, include: The unit includes a breath sampling unit (100), a gas analysis unit (200), and a control and calculation unit (300). The exhalation sampling unit (100) is used to collect exhalation samples; The gas analysis unit (200) consists of a three-way valve (201), an analysis pump (202), an electrochemical sensor module (203), and a filter (204); Both the exhalation sampling unit (100) and the gas analysis unit (200) are connected to the control and calculation unit (300); The control and calculation unit (300) is used to control the three-way valve (201) to close when the ratio of the output signal to the saturation signal is less than a preset threshold, so that the exhaled sample is drawn into the electrochemical sensor module (203) by the analysis pump (202), and to control the three-way valve (201) to switch rapidly between closing and opening according to the real-time output signal magnitude when the ratio of the output signal to the saturation signal is greater than the preset threshold, so that the exhaled sample is mixed with the zero-point gas filtered by the filter (204) before entering the electrochemical sensor module (203), and to calculate the gas concentration in the exhaled sample according to the output signal, sensitivity and the proportion of the closing time of the three-way valve (201); wherein, the output signal is the signal after the microcurrent output by the electrochemical sensor module (203) is conditioned by the amplification link and sampled by the analog-to-digital converter; the saturation signal is the maximum signal value of the subsequent circuits including the amplification link and the analog-to-digital converter to maintain a linear working state.
2. The high-precision, wide-range exhalation detection device according to claim 1, characterized in that, The exhalation sampling unit (100) consists of a buffer chamber (103) and a two-way valve (102) connected in series, and a pressure sensor (104) is connected in the air path. The buffer chamber (103) is used to collect, store, and stabilize the exhaled breath sample; The pressure sensor (104) is used to detect pressure changes in the airway and the buffer chamber (103) and feed them back to the control and calculation unit (300) to ensure that the exhaled breath sample in the buffer chamber (103) is sufficient and stable. The two-way valve (102) is used to control the opening and closing of the buffer chamber (103) so that the exhaled breath sample enters the gas analysis unit (300).
3. The high-precision, wide-range exhalation detection device according to claim 1, characterized in that, The electrochemical sensor module (203) is a single electrochemical sensor.
4. The high-precision, wide-range exhalation detection device according to claim 1, characterized in that, The electrochemical sensor module (203) is a module composed of multiple electrochemical sensors.
5. The high-precision, wide-range exhalation detection device according to claim 1, characterized in that, Based on the output signal, sensitivity, and the proportion of the three-way valve (201) closing time, the gas concentration in the exhaled sample is calculated as follows: in, The concentration of the gas being measured; The output signal; Sensitivity; This represents the percentage of the closing time of the three-way valve (201).
6. A high-precision, wide-range breath detection method utilizing the high-precision, wide-range breath detection device according to any one of claims 1-5, characterized in that, include: Step 1: Control the exhaled breath sample to enter the gas analysis unit (200); Step 2: When the ratio of the output signal to the saturation signal is less than a preset threshold, the three-way valve (201) is controlled to close, so that the exhaled sample is drawn into the electrochemical sensor module (203) by the analysis pump (202). When the ratio of the output signal to the saturation signal is greater than the preset threshold, the three-way valve (201) is controlled to switch rapidly between closing and opening according to the real-time output signal magnitude, so that the exhaled sample is mixed with the zero-point gas filtered by the filter (204) before entering the electrochemical sensor module (203). The output signal is the signal after the microcurrent output by the electrochemical sensor module (203) is conditioned by the amplification link and sampled by the analog-to-digital converter. The saturation signal is the maximum signal value of the subsequent circuits, including the amplification link and the analog-to-digital converter, that maintains a linear working state. Step 3: Calculate the gas concentration in the exhaled sample based on the output signal, sensitivity, and the proportion of the closing time of the three-way valve (201).