CN113558659B - High-precision ultrasonic lung function detector and detection method thereof - Google Patents
High-precision ultrasonic lung function detector and detection method thereof Download PDFInfo
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/44—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
- A61B8/58—Testing, adjusting or calibrating the diagnostic device
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
- G01F1/667—Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters
- G01F1/668—Compensating or correcting for variations in velocity of sound
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K17/00—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
- G06K17/0022—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations arrangements or provisious for transferring data to distant stations, e.g. from a sensing device
- G06K17/0029—Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations arrangements or provisious for transferring data to distant stations, e.g. from a sensing device the arrangement being specially adapted for wireless interrogation of grouped or bundled articles tagged with wireless record carriers
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- G—PHYSICS
- G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
- G16H—HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA
- G16H40/00—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices
- G16H40/60—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices for the operation of medical equipment or devices
- G16H40/67—ICT specially adapted for the management or administration of healthcare resources or facilities; ICT specially adapted for the management or operation of medical equipment or devices for the operation of medical equipment or devices for remote operation
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2560/00—Constructional details of operational features of apparatus; Accessories for medical measuring apparatus
- A61B2560/02—Operational features
- A61B2560/0242—Operational features adapted to measure environmental factors, e.g. temperature, pollution
- A61B2560/0247—Operational features adapted to measure environmental factors, e.g. temperature, pollution for compensation or correction of the measured physiological value
- A61B2560/0252—Operational features adapted to measure environmental factors, e.g. temperature, pollution for compensation or correction of the measured physiological value using ambient temperature
Abstract
The invention discloses a high-precision ultrasonic pulmonary function detector and a detection method thereof, the detector comprises a blowing pipe and a plurality of nozzles, wherein two ultrasonic sensors are arranged on the blowing pipe, any nozzle can be movably arranged in the blowing pipe in a penetrating mode, the ultrasonic sensors are connected with a change-over switch, the change-over switch is connected with an amplifying circuit and an amplitude change circuit, the two amplitude change circuits are connected with the same boosting circuit and the same pulse emission and precision time measurement chip, the amplifying circuit is connected with a band-pass filter circuit, the two band-pass filter circuits are connected with the pulse emission and precision time measurement chip, the pulse emission and precision time measurement chip is connected with a microcontroller in a serial communication mode, the microcontroller controls the two change-over switches respectively, the microcontroller is connected with a server in a communication mode, and the server is electrically connected with an environment parameter detector. The invention can measure the flow velocity without obstructing the respiration, has no pressure loss, extremely high sensitivity and wide measuring range, and the measured flow velocity can obtain the respiration flow through integral calculation.
Description
Technical Field
The invention relates to the technical field of medical detection, in particular to a high-precision ultrasonic lung function detector and a detection method thereof.
Background
With the economic development, environmental pollution is more and more serious, and more people suffer from respiratory diseases. The lung function examination is one of the necessary examination of respiratory diseases, and the lung function is measured by a lung function instrument, so that the purpose of detecting respiratory abnormality is achieved. Has important guiding significance for early detection of lung and respiratory tract lesions, such as chronic bronchitis, emphysema, bronchial asthma, intermittent lung diseases and the like.
The ultrasonic gas flow measurement technique has the following advantages: (1) high precision; (2) no moving parts, reliability and long service life; (3) The flow measurement result is affected by environmental parameters such as gas components, pressure, temperature and humidity, and the repeatability is good; (4) good stability, avoiding the trouble of frequent calibration; (5) easy disinfection and cross infection prevention. At present, the scheme of the ultrasonic pulmonary function instrument is that two small ultrasonic sensors are arranged at the upstream and downstream of a blowpipe, and the core technology of the pulmonary function instrument is the sensor technology, and the focus is the flow sensor. The relation between the propagation time difference of ultrasonic wave in forward flow and backward flow and the gas flow is utilized to measure the instantaneous flow and obtain various lung function indexes through a certain corresponding relation. However, since the application occasion of the ultrasonic pulmonary function instrument is a blowpipe with a very small pipe diameter, the flow rate of gas is very large under the condition of the same flow, so that an ultrasonic signal is greatly attenuated and even submerged in noise, and the measurement accuracy is greatly influenced, thereby limiting the measurement range.
Methods for measuring gas flow using ultrasonic waves can be broadly divided into four types: frequency difference method, correlation method, doppler method and time difference method. The frequency difference method and the correlation method have lower resolution and are difficult to realize, so that the practical application is less. The Doppler effect method is measured by utilizing the Doppler effect that the ultrasonic wave generates frequency shift due to the reflection of suspended particles or bubbles in the fluid in the propagation process, is mainly used for multiphase fluid with larger journal particles, and is suitable for measuring the fluid with more impurities and uniform distribution. Since the Doppler method is affected by temperature change and scattering body, correction is needed, and the correction process is complex, the Doppler method has less practical application. Based on the two factors of difficulty and realizability, the gas ultrasonic flowmeter with the largest production and the largest application range is mainly realized by adopting a time difference method. The time difference method is to measure by using the principle that the propagation speed of ultrasonic waves in fluid changes along with the speed change of the fluid, calculate the flow velocity v by measuring the time difference Δt of the forward and backward propagation of ultrasonic waves, and then calculate the flow according to q=s×v. The jet lag flowmeter is mainly applied to single-phase liquid and is suitable for measuring clean water in industry. Because the propagation efficiency of ultrasonic waves in gas is lower, the signal attenuation is larger, the frequency of the ultrasonic waves is high, the noise is large, the signal to noise ratio is difficult to improve, the pipe diameter of the pulmonary function instrument is very small, and the accuracy improvement is difficult.
In addition, the pulmonary function instrument can be repeatedly used for detection in different time periods in one day, and in the actual use process, the detection instrument is not standard in use, for example, cross infection can be caused if different patients use the same mouthpiece for detection, and the caused detection result is inaccurate.
Disclosure of Invention
In order to solve the technical problems, the invention provides the high-precision ultrasonic lung function detector without pressure loss and with wide real-time correction range for the ultrasonic sound velocity and the detection method thereof.
The technical scheme adopted by the invention is as follows: the utility model provides a high accuracy ultrasonic wave pulmonary function detector, includes the blowpipe and sets up two ultrasonic sensor on the blowpipe, the key lies in: the signal output ends of the two ultrasonic sensors are positioned in the blowpipe and are opposite to the blowpipe, the ultrasonic sensors are connected with a change-over switch, the change-over switch is connected with an amplifying circuit and an amplitude change circuit, the two amplitude change circuits are connected with one boosting circuit and one pulse transmitting and precise time measuring chip, the amplifying circuit is connected with a band-pass filter circuit, the two band-pass filter circuits are connected with the pulse transmitting and precise time measuring chip, the pulse transmitting and precise time measuring chip is connected with a microcontroller in serial communication mode, the microcontroller respectively controls the two change-over switches, the microcontroller is connected with a server in communication mode, the server is electrically connected with an environmental parameter detector, and the high-precision ultrasonic pulmonary function detector function can be realized by mutually matching a zero-crossing detection correction method and a real-time compensation correction method by matching with programs of the microcontroller based on the above hardware connection.
Preferably, an included angle α is formed between the connection line of the two ultrasonic sensors and the blowpipe, and the included angle α is 0< α <90 °.
Preferably, the environmental parameter detector comprises a temperature detection module, a humidity detection module and an air pressure detection module.
Preferably, a shielding cover is arranged outside the amplifying circuit and the band-pass filter circuit.
The effect of the above scheme is that the change-over switch is used for switching the working state (transmitting/receiving) of the ultrasonic sensor, the transmitting, namely driving signal directly acts on the ultrasonic sensor, and the receiving, namely the signal of the ultrasonic sensor is connected to the amplifying circuit; the band-pass filter circuit is used for shielding interference signals except the working frequency, and only signals with a certain frequency band are selected for measurement. A plurality of band-pass filter circuits can be connected in series in the circuit, so that the filtering effect is better; the amplifying circuit is used for amplifying the signal of the ultrasonic sensor, and the signal amplitude of the ultrasonic sensor is very small, so that threshold detection and judgment are difficult to carry out, and the signal amplification is more conducive to threshold detection and zero crossing detection; the amplitude change circuit is used for improving the amplitude of the transmitting signal of the signal generator, the transmitting signal of the signal generator directly drives the ultrasonic sensor to have small power, and the amplitude is improved by controlling the grid driver or the high-speed driving circuit, so that the ultrasonic transmitting power is increased; the booster circuit is used for providing stable voltage for the amplitude variation part; the pulse transmitting and precise time measuring chip is provided with a programmable transmitting pulse and precise time period counting chip/module, and is used for respectively measuring the upstream and downstream flight time and calculating the transit time difference so as to calculate the flow velocity value; the environment parameter detector is used for detecting the real-time temperature and the real-time humidity of the environment, and the plurality of biting mouthpieces can be suitable for the condition of patients with different vital capacities to select, so that the detection accuracy is improved.
The detection method of the high-precision ultrasonic lung function detector is characterized in that: the microcontroller sends a start detection signal to the pulse transmitting and precise time measuring chip, meanwhile, the upstream ultrasonic sensor is switched to transmit, the downstream ultrasonic sensor is switched to receive, the pulse transmitting and precise time measuring chip starts timing and sends 2 continuous pulse signals, the amplitude of the 2 pulse signals is increased through the booster circuit and the amplitude changing circuit, and the 2 continuous pulse signals are added to the upstream ultrasonic sensor; the downstream ultrasonic sensor receives the ultrasonic signal, and transmits the ultrasonic signal to the pulse transmitting and precise time measuring chip after being processed by the amplifying circuit and the band-pass filter circuit, the pulse transmitting and precise time measuring chip judges the end of timing according to the set threshold value and zero crossing point, and calculates the transit time t up The method comprises the steps of carrying out a first treatment on the surface of the Similarly, the ultrasonic sensor at the upstream is switched to receive the ultrasonic signal, the ultrasonic sensor at the downstream is switched to the ultrasonic signal, and the same mode is adopted to calculateTime of flight t down The method comprises the steps of carrying out a first treatment on the surface of the For the transit time t measured in the high and low flow velocity region up And t down The zero-crossing detection correction method is adopted to respectively correct, and the volume flow V is obtained through calculation Measurement of The method comprises the steps of carrying out a first treatment on the surface of the And simultaneously adopts a real-time compensation correction method to correct the volume flow V Measurement of Real-time environmental parameter correction is carried out to finally obtain volume flow V BTPS 。
Preferably, the zero-crossing detection correction method is as follows: s1, a threshold voltage is set in advance, when the amplitude of a received signal of an ultrasonic sensor reaches a threshold value, zero-crossing detection is started, a plurality of zero-crossing points can be set as timing end points, and the transit time t can be obtained up And t down Through t up And t down Calculating a fluid flow velocity v; s2, because the ultrasonic wave propagates in the high-flow-rate gas medium and has larger attenuation, the preset threshold voltage does not detect the sound wave to be detected, namely the sound wave with the lead/lag period is detected so as to lead the transit time t up Or t down The occurrence of deviations of t' and t ", defining the moments of successive three points a, b and c on the flow-time curve of the breathing process, are t1, t2 and t3 respectively, the corresponding flow rates being v respectively 1 ，v 2 And v 3 ，Δy 1 And Deltay 2 For the difference in flow velocity between two successive points, i.e. deltay 1 ＝v 2 -v 1 ，Δy 2 ＝v 3 -v 2 Let m be the sum of the absolute flow rates of two points a, b, i.e. m= |v 1 |+|v 2 I, used to determine whether it is a low flow rate region or a high flow rate region, set m mid As a limit value, when m<m mid In the case of a low flow rate region, when m>m mid When the flow rate is in a high flow rate region, the abnormal flow rates in the low flow rate region and the high flow rate region are respectively corrected by adopting different data correction algorithms; s3, since the measured fluid flow velocity V is actually the linear average velocity on the inner diameter of the pipe section, and the measured flow rate is the surface average flow velocity V' of the pipe inner section, the volume flow V Measurement of Then the calculation is performed using the method of 7,
wherein t is 1 And t 2 For the time at which flow measurement starts and ends, D is the diameter of the line, v' =kv, and k is the reynolds number correction coefficient.
Preferably, in the step S1: t is t up Calculation using 1
t down Calculation using 2
Wherein L is the length of a sound channel, c is the sound velocity of ultrasonic waves, θ is the axial included angle between the sound channel and a pipeline, v is the flow velocity of fluid, and the forward and backward transit time difference deltat is calculated by adopting 3:
due to c 2 ＞＞v 2 cos 2 θ, Δt can be reduced to equation 4:
whereby the flow velocity v is calculated using equation 5:
preferably, in the step S2, the abnormal data in the low flow velocity region is filtered by an average filtering method, and |Δy is set 2 | max Threshold value for abnormal flow rate data in low flow rate region, i.e., |Δy 2 |＞|Δy 2 | max When the flow velocity data is determined to be abnormal, the corrected flow velocity is v 3 ′＝(v 1 +v 2 ) 2; the following filtering algorithm is used for the abnormal data of the high flow rate region:
let Δy be 3 ＝|Δy 1 |+|Δy 2 I, Δy can be obtained 3 -time profile, setting a decision threshold ay max When Deltay 3 ＞Δy max If it is determined that the data is erroneous, data correction is necessary, and in this case, if Δy 1 >A positive period flow velocity difference, the correction method is that Δt minus one ultrasonic clock period, i.e., Δt' =Δt-1/f; if Deltay 1 <A negative cycle flow rate difference, the correction method is to add an ultrasonic clock cycle to Δt, i.e., Δt "=Δt+1/f, and the flow rate values v 'and v" calculated by Δt' and Δt "are corrected flow rate values.
Preferably, the real-time compensation correction method is as follows: s1, judging whether the test state of a user is an inspiration process or an expiration process according to a formula 3; s2, sound velocity correction: respectively correcting the ultrasonic sound velocity c by adopting a sound velocity correction formula according to different test states; s3, correcting the BTPS in real time: for different test states, the volume flow V is respectively Measurement of Correction by 10, V BTPS =correction coefficient×v Measurement of (equation 10) wherein the correction coefficient is calculated using the BTPS correction formula.
Preferably, the sound velocity correction specifically includes: when deltat is more than 0 and deltat is less than 0, the method is an inspiration process, the inspiration process adopts the real-time temperature T measured by the environmental parameter detector to calibrate the ultrasonic sound velocity c, and the expiration process adopts the medical expiration temperature empirical value to calibrate the ultrasonic sound velocity c sound velocity; the real-time BTPS correction is specifically: when deltat is more than 0 and deltat is less than 0, the volume flow V is corrected by using the real-time temperature T, humidity H and current air pressure value measured by the environmental parameter detector, and the volume flow V is corrected by using the medical expiration temperature and humidity empirical values. Compared with the prior art, the high-precision ultrasonic lung function detector and the detection method provided by the invention have the following effects: (1) The ultrasonic lung function detector realizes bidirectional flow measurement through the transceiver-type ultrasonic sensor, and improves the transmitting voltage, increases the transmitting power, improves the signal-to-noise ratio of a receiving end, reduces the amplification factor and inhibits self-oscillation and noise through the booster circuit and the amplitude change circuit; the amplifying circuit and the band-pass filter circuit are used for avoiding the transmitted signal from being interfered by space spurious signals, especially pulse groups, and average value filtering is carried out on the abnormal data, so that the static data is more stable; a shielding cover is arranged outside the amplifying circuit and the band-pass filter circuit to shield electromagnetic radiation interference; the environmental temperature and humidity can be acquired in real time through the environmental parameter detector, and the temperature and the humidity are transmitted to the controller in real time for real-time correction, so that the use is simpler and more convenient, and the measurement result is more accurate; different mouthpiece tubes can be selected for testing according to the patient conditions of different vital capacities, and the detection accuracy is improved. (2) In a high flow rate area, a transmission medium is discontinuous, the amplitude of an ultrasonic signal is changed, and a preset period of straight adjacent first wave jump easily occurs when a fixed threshold value is judged; (3) The invention adopts a real-time compensation correction method to correct the ultrasonic sound velocity, so that the measurement result is more accurate; (4) The invention can measure the flow velocity without obstructing the respiration, has no pressure loss, extremely high sensitivity and wide measuring range, and the measured flow velocity can obtain the respiration flow through integral calculation.
Drawings
FIG. 1 is a block diagram of a hardware system design of the present invention;
FIG. 2 is a graph of flow velocity versus time for ultrasonic propagation in a high flow velocity zone;
fig. 3 is a flowchart of the zero-crossing detection correction method.
Detailed Description
The present invention will be described in detail below with reference to the drawings and detailed description to enable those skilled in the art to better understand the technical scheme of the present invention.
As shown in figures 1-3, a high-precision ultrasonic pulmonary function detector comprises a blowing pipe 1 and a plurality of mouthpiece pipes 3, wherein two ultrasonic sensors 2 are arranged on the blowing pipe 1, any one mouthpiece pipe 3 can be movably arranged in the blowing pipe 1 in a penetrating way, signal output ends of the two ultrasonic sensors 2 are positioned in the blowing pipe 1 and are opposite to each other, an included angle alpha is formed between a connecting line of the two ultrasonic sensors 2 and the blowing pipe 1, the included angle alpha is 0< alpha <90 degrees, the ultrasonic sensors 2 are connected with a switch, the switch is connected with an amplifying circuit and an amplitude change circuit, the two amplitude change circuits are connected with one boosting circuit and one pulse transmitting and precise time measuring chip, the amplifying circuit and the bandpass filter circuit are externally provided with shielding covers, the two bandpass filter circuits are connected with the pulse transmitting and the precise time measuring chip, the pulse transmitting and precise time measuring chip are in communication connection with a microcontroller, the microcontroller is in serial communication connection, the two microcontroller is in communication connection with the microcontroller, the two microcontroller are in communication connection with the microcontroller, and the microcontroller is in communication with the microcontroller.
The lung function detector detects the workflow:
the microcontroller sends a start detection signal to the pulse transmitting and precise time measuring chip, meanwhile, the upstream ultrasonic sensor is switched to transmit, the downstream ultrasonic sensor is switched to receive, the pulse transmitting and precise time measuring chip starts timing and sends 2 continuous pulse signals, the amplitude of the 2 pulse signals is increased through the booster circuit and the amplitude changing circuit, and the 2 continuous pulse signals are added to the upstream ultrasonic sensor;
the downstream ultrasonic sensor receives ultrasonic signals (ultrasonic frequency is 20kHZ-30 MHz), the ultrasonic signals are processed by an amplifying circuit and a band-pass filter circuit and transmitted to a pulse transmitting and precise time measuring chip, the pulse transmitting and precise time measuring chip judges the end of timing according to a set threshold value and zero crossing point, and the transit time t is calculated up ；
Same reasonThe transit time t can be calculated by switching the upstream ultrasonic sensor to receive ultrasonic signals and the downstream ultrasonic sensor to transmit ultrasonic signals in the same pattern down 。
The detection method of the high-precision ultrasonic pulmonary function detector is to respectively correct the transit time of ultrasonic signals detected by an ultrasonic sensor in a high-flow-rate area and a low-flow-rate area by adopting a zero-crossing detection correction method, and calculate to obtain the volume flow V Measurement of The method comprises the steps of carrying out a first treatment on the surface of the And simultaneously adopts a real-time compensation correction method to correct the volume flow V Measurement of Real-time environmental parameter correction is carried out to finally obtain volume flow V BTPS ；
Wherein, the zero-crossing detection correction method is as follows: s1, a threshold voltage is set in advance, when the amplitude of a received signal of an ultrasonic sensor reaches a threshold value, zero-crossing detection is started, a plurality of zero-crossing points can be set as timing end points, and the transit time t can be obtained up And t down Through t up And t down Calculating a fluid flow velocity v; t is t up Calculation using 1
t down Calculate +.2 using>
Wherein L is the length of a sound channel, c is the sound velocity of ultrasonic waves, θ is the axial included angle between the sound channel and a pipeline, v is the flow velocity of fluid, and the forward and backward transit time difference deltat is calculated by adopting 3:
due to c 2 ＞＞v 2 cos 2 α, Δt can be reduced to formula 4:
whereby the flow velocity v is calculated using equation 5:
s2, because the ultrasonic wave propagates in the high-flow-rate gas medium and has larger attenuation, the preset threshold voltage does not detect the sound wave to be detected, namely the sound wave with the lead/lag period is detected so as to lead the transit time t up Or t down The occurrence of deviations of t' and t ", defining the moments of successive three points a, b and c on the flow-time curve of the breathing process, are t1, t2 and t3 respectively, the corresponding flow rates being v respectively 1 ，v 2 And v 3 ，Δy 1 And Deltay 2 For the difference in flow velocity between two successive points, i.e. deltay 1 ＝v 2 -v 1 ，Δy 2 ＝v 3 -v 2 Let m be the sum of the absolute flow rates of two points a, b, i.e. m= |v 1 |+|v 2 I, used to determine whether it is a low flow rate region or a high flow rate region, set m mid As a limit value, when m<m mid In the case of a low flow rate region, when m>m mid When the flow rate is in a high flow rate region, the abnormal flow rates in the low flow rate region and the high flow rate region are respectively corrected by adopting different data correction algorithms; filtering abnormal data in a low flow speed area by adopting a mean value filtering method, and setting |delta y 2 | max Threshold value for abnormal flow rate data in low flow rate region, i.e., |Δy 2 |＞|Δy 2 | max When the flow velocity data is determined to be abnormal, the corrected flow velocity is v 3 ′＝(v 1 +v 2 ) 2; the following filtering algorithm is used for the abnormal data of the high flow rate region: let Δy be 3 ＝|Δy 1 |+Δy 2 I, Δy can be obtained 3 -time profile, setting a decision threshold ay max When Deltay 3 ＞Δy max If it is determined that the data is erroneous, data correction is necessary, and in this case, if Δy 1 >A positive period flow velocity difference, the correction method is that Δt minus one ultrasonic clock period, i.e., Δt' =Δt-1/f; if Deltay 1 <A negative cycle flow rate difference, the correction method is to add an ultrasonic clock cycle to Δt, i.e., Δt "=Δt+1/f, the flow rate calculated by Δt' and Δt"The values v' and v "are corrected flow rate values;
s3, since the measured fluid flow velocity V is actually the linear average velocity on the inner diameter of the pipe section, and the measured flow rate is the surface average flow velocity V' of the pipe inner section, the volume flow V Measurement of Then the calculation is performed using the method of 7,
wherein t is 1 And t 2 For the time of beginning and ending of flow measurement, D is the diameter of the pipeline, v' =kv, k is the reynolds number correction coefficient;
the real-time compensation correction method comprises the following steps: judging whether the test state of the user is an inspiration process or an expiration process according to the formula 3; when deltat is more than 0 and deltat is less than 0, the breathing process is performed, the real-time temperature T measured by the environment parameter detector is used for calibrating the ultrasonic sound velocity c, the medical breathing temperature empirical value is used for calibrating the ultrasonic sound velocity c, and the ultrasonic sound velocity c is corrected by adopting a sound velocity correction formula; when deltat is more than 0 and deltat is less than 0, the inspiration is the expiration, and the real-time temperature T, humidity H and air pressure P measured by the environmental parameter detector are used for measuring the volume flow V Measurement of Correcting, exhaling, and using medical exhaling temperature and humidity empirical value to make volume flow V Measurement of Correction is performed using equation 10, V BTPS =correction coefficient×v Measurement of (equation 10) wherein the correction coefficient is calculated using a BTPS correction formula;
the sound velocity correction formula:
BTPS correction formula:
pw was calculated using the Goff-Gratch formula revised in 2000.
Finally, it should be noted that the above description is only a preferred embodiment of the present invention, and that many similar changes can be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (9)
1. A detection method of a high-precision ultrasonic lung function detector is characterized in that: the microcontroller sends a start detection signal to the pulse transmitting and precise time measuring chip, meanwhile, the upstream ultrasonic sensor is switched to transmit, the downstream ultrasonic sensor is switched to receive, the pulse transmitting and precise time measuring chip starts timing and sends 2 continuous pulse signals, the amplitude of the 2 pulse signals is increased through the booster circuit and the amplitude change circuit and is added to the upstream ultrasonic sensor, the downstream ultrasonic sensor receives the ultrasonic signals, the ultrasonic signals are processed through the amplifier circuit and the band-pass filter circuit and are transmitted to the pulse transmitting and precise time measuring chip, the pulse transmitting and precise time measuring chip judges the timing end according to the set threshold value and zero crossing point, and the transit time t is calculated up The method comprises the steps of carrying out a first treatment on the surface of the Switching the upstream ultrasonic sensor to receive ultrasonic signal, switching the downstream ultrasonic sensor to transmit ultrasonic signal, and calculating transit time t by the same mode down The method comprises the steps of carrying out a first treatment on the surface of the For the transit time t measured in the high and low flow velocity region up And t down The zero-crossing detection correction method is adopted to respectively correct, and the volume flow V is obtained through calculation Measurement of The method comprises the steps of carrying out a first treatment on the surface of the And simultaneously adopts a real-time compensation correction method to correct the volume flow V Measurement of Real-time environmental parameter correction is carried out to finally obtain volume flow V BTPS ；
Wherein, the zero-crossing detection correction method is as follows: s1, a threshold voltage is set in advance, when the amplitude of a received signal of an ultrasonic sensor reaches a threshold value, zero-crossing detection is started, a plurality of zero-crossing points can be set as timing end points, and the transit time t can be obtained up And t down Through t up And t down Calculating a fluid flow velocity v; s2, because the ultrasonic wave propagates in the high-flow-rate gas medium and has larger attenuation, the preset threshold voltage does not detect the sound wave to be detected, namely the sound wave with the lead/lag period is detected so as to lead the transit time t up Or t down The occurrence of deviations of t' and t ", defining the moments of successive three points a, b and c on the flow-time curve of the breathing process, are t1, t2 and t3 respectively, the corresponding flow rates being v respectively 1 ，v 2 And v 3 ，Δy 1 And Deltay 2 For the difference in flow velocity between two successive points, i.e. deltay 1 ＝v 2 -v 1 ，Δy 2 ＝v 3 -v 2 Let m be the sum of the absolute flow rates of two points a, b, i.e. m= |v 1 |+|v 2 I, used to determine whether it is a low flow rate region or a high flow rate region, set m mid As a limit value, when m<m mid In the case of a low flow rate region, when m>m mid When the flow rate is in a high flow rate region, the abnormal flow rates in the low flow rate region and the high flow rate region are respectively corrected by adopting different data correction algorithms; s3, since the measured fluid flow velocity V is actually the linear average velocity on the inner diameter of the pipe section, and the measured flow rate is the surface average flow velocity V' of the pipe inner section, the volume flow V Measurement of Then the calculation is performed using the method of 7,
wherein t is 1 And t2 is the time at which the flow measurement starts and ends, D is the diameter of the line, v' =kv, and k is the reynolds number correction coefficient.
2. The method for detecting a high-precision ultrasonic pulmonary function detector according to claim 1, wherein in S1: t is t up Calculated using formula 1:
t down calculated using formula 2:
wherein L is the length of a sound channel, c is the sound velocity of ultrasonic waves, θ is the axial included angle between the sound channel and a pipeline, v is the flow velocity of fluid, and the forward and backward transit time difference deltat is calculated by adopting 3:
due to c 2 ＞＞v 2 cos 2 θ, Δt can be reduced to equation 4:
whereby the flow velocity v is calculated using equation 5:
3. the method for detecting the high-precision ultrasonic pulmonary function detector according to claim 1, wherein: in the S2, filtering abnormal data in a low flow speed area by adopting a mean value filtering method, and setting |delta y 2 | max Threshold value for abnormal flow rate data in low flow rate region, i.e., |Δy 2 |＞|Δy 2 | max When the flow velocity data is determined to be abnormal, the corrected flow velocity is v 3 ′＝(v 1 +v 2 ) 2; the following filtering algorithm is used for the abnormal data of the high flow rate region: let Δy be 3 ＝|Δy 1 |+|Δy 2 I, Δy can be obtained 3 -time profile, setting a decision threshold ay max When Deltay 3 ＞Δy max If it is determined that the data is erroneous, data correction is necessary, and in this case, if Δy 1 >A positive period flow velocity difference, the correction method is that Δt minus one ultrasonic clock period, i.e., Δt' =Δt-1/f; if Deltay 1 <A negative period flow rate difference, the correction method is that deltat is added with an ultrasonic clock period, namely deltatt "=Δt+1/f, and the flow velocity values v 'and v" calculated with Δt' and Δt "are corrected flow velocity values.
4. The method for detecting the high-precision ultrasonic pulmonary function detector according to claim 2, wherein: the real-time compensation correction method comprises the following steps: s1, judging whether the test state of a user is an inspiration process or an expiration process according to a formula 3; s2, sound velocity correction: respectively correcting the ultrasonic sound velocity c by adopting a sound velocity correction formula according to different test states; s3, correcting the BTPS in real time: for different test states, the volume flow V is respectively Measurement of The correction is performed using the method 10 of the present invention,
V BTPS =correction coefficient×v Measurement of 10. The method of the invention
Wherein the correction coefficient is calculated using a BTPS correction formula.
5. The method for detecting the high-precision ultrasonic pulmonary function detector according to claim 4, wherein: the sound velocity correction is specifically: when deltat is more than 0 and deltat is less than 0, the method is an inspiration process, the inspiration process adopts the real-time temperature T measured by the environmental parameter detector to calibrate the ultrasonic sound velocity c, and the expiration process adopts the medical expiration temperature empirical value to calibrate the ultrasonic sound velocity c sound velocity; the real-time BTPS correction is specifically: when deltat is more than 0 and deltat is less than 0, the volume flow V is corrected by using the real-time temperature T, humidity H and current air pressure value measured by the environmental parameter detector, and the volume flow V is corrected by using the medical expiration temperature and humidity empirical values.
6. A high-precision ultrasonic pulmonary function detector employing the detection method of claim 1, wherein: the automatic air-conditioning device comprises a blowing pipe (1) and a plurality of mouthpiece pipes (3), wherein two ultrasonic sensors (2) are arranged on the blowing pipe (1), any one mouthpiece pipe (3) can be movably arranged in the blowing pipe (1) in a penetrating mode, the signal output ends of the two ultrasonic sensors (2) are located in the blowing pipe and are opposite to the arrangement, the ultrasonic sensors (2) are connected with a change-over switch, the change-over switch is connected with an amplifying circuit and an amplitude change circuit, the two amplitude change circuits are connected with the same boost circuit and the same pulse transmitting and precision time measuring chip, the amplifying circuit is connected with a band-pass filter circuit, the two band-pass filter circuits are connected with the pulse transmitting and precision time measuring chip, the pulse transmitting and precision time measuring chip is connected with a microcontroller in a serial communication mode, the microcontroller is respectively used for controlling the two change-over switches, the microcontroller is connected with a server in a communication mode, an environment parameter detector is installed on the server, and the microcontroller is matched with a program to realize high-precision correction function of a real-time compensation lung function by utilizing a real-time correction method.
7. The high-precision ultrasonic pulmonary function detector according to claim 6, wherein: an included angle alpha is formed between the connecting line of the two ultrasonic sensors (2) and the blowpipe (1), and the included angle alpha is 0< alpha <90 degrees.
8. The high-precision ultrasonic pulmonary function detector according to claim 6, wherein: the environment parameter detector comprises a temperature detection module, a humidity detection module and an air pressure detection module.
9. The high-precision ultrasonic pulmonary function detector according to claim 6, wherein: and shielding covers are arranged outside the amplifying circuit and the band-pass filter circuit.
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Citations (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH078472A (en) * | 1993-06-23 | 1995-01-13 | Nippondenso Co Ltd | Breathing amount measurement device |
| JPH07178086A (en) * | 1993-12-21 | 1995-07-18 | Toshiba Corp | Method for ultrasonic diagnosis and system therefor |
| JPH11318860A (en) * | 1998-05-20 | 1999-11-24 | Anima Kk | Oxygen consumption meter |
| WO2002024070A1 (en) * | 2000-09-20 | 2002-03-28 | Peter Ganshorn | Device for rapidly determining the diffusion capacity of a lung |
| CN1343107A (en) * | 1999-03-12 | 2002-04-03 | 梅德拉股份有限公司 | Controlling contrast enhanced imaging procedures |
| CN1395678A (en) * | 2000-10-10 | 2003-02-05 | 松下电器产业株式会社 | Flow measuring device |
| CN1492735A (en) * | 2001-02-23 | 2004-04-28 | ������¡���ˡ��������� | Non invasive measurements of chemical substances |
| CN101326427A (en) * | 2005-12-08 | 2008-12-17 | 大陆汽车有限责任公司 | Device for determining a mass flow |
| CN101354394A (en) * | 2008-09-08 | 2009-01-28 | 无锡尚沃生物科技有限公司 | Expiration nitric oxide detection device |
| CN102027386A (en) * | 2008-01-09 | 2011-04-20 | 海浪科技有限公司 | Nonlinear elastic imaging with two-frequency elastic pulse complexes |
| CN202078295U (en) * | 2010-06-01 | 2011-12-21 | 谭伟 | Near-infrared laser system for inspecting deep vein thrombosis |
| CA2836278A1 (en) * | 2010-10-21 | 2012-04-26 | Yoram Palti | Measuring pulmonary blood pressure using transthoracic pulmonary doppler ultrasound |
| CN103630174A (en) * | 2013-12-07 | 2014-03-12 | 重庆前卫科技集团有限公司 | Flow measuring method of ultrasonic flow meter |
| CN103948401A (en) * | 2014-05-20 | 2014-07-30 | 夏云 | Portable lung function instrument and lung function detection method |
| CN103989488A (en) * | 2014-04-09 | 2014-08-20 | 河南迈松医用设备制造有限公司 | Wide-range ultrasonic pulmonary function instrument and calculation method thereof |
| CN204190393U (en) * | 2014-10-21 | 2015-03-04 | 重庆路之生科技有限责任公司 | The meticulous reactive power compensator of low pressure |
| CN104605857A (en) * | 2015-02-12 | 2015-05-13 | 上海朔茂网络科技有限公司 | Lung function measuring method |
| CN105581796A (en) * | 2014-11-10 | 2016-05-18 | ndd医药技术股份有限公司 | Breathing tube for use in ultrasonic flow measurement systems |
| CN105698884A (en) * | 2016-03-07 | 2016-06-22 | 上海电气自动化设计研究所有限公司 | Improved measurement method of time difference type ultrasonic flow meter |
| CN106422638A (en) * | 2016-12-05 | 2017-02-22 | 王睿智 | Air haze purification device |
| CN107242874A (en) * | 2017-05-26 | 2017-10-13 | 台州亿联健医疗科技有限公司 | Flow sensor, spirometer and application for lung function tests |
| CN109640827A (en) * | 2016-03-23 | 2019-04-16 | 皇家飞利浦有限公司 | Method and apparatus for improving the measurement of velocity of blood flow |
| CN109637662A (en) * | 2019-02-14 | 2019-04-16 | 广东工业大学 | A kind of pulmonary function detection and the method and system of data statistics |
| WO2019102384A1 (en) * | 2017-11-22 | 2019-05-31 | Fisher & Paykel Healthcare Limited | Respiratory rate monitoring for respiratory flow therapy systems |
| CN109839855A (en) * | 2017-11-27 | 2019-06-04 | 张旭 | A kind of control circuit of ultrasound lung function instrument |
| CN109937000A (en) * | 2016-10-20 | 2019-06-25 | 海尔斯安普有限责任公司 | Portable spirometer |
| CN110169786A (en) * | 2019-05-21 | 2019-08-27 | 广州畅呼医疗器械有限公司 | A kind of ultrasonic drive circuit, driving method and ultrasonic lung function instrument |
| CN110200632A (en) * | 2019-07-01 | 2019-09-06 | 武汉市澄心小匠科技有限公司 | A kind of Portable lung function detecting instrument |
| CN209548088U (en) * | 2018-12-28 | 2019-10-29 | 重庆安酷科技有限公司 | Pulmonary function detection cart |
| CN111329482A (en) * | 2020-04-03 | 2020-06-26 | 夏云 | Pulmonary function instrument testing head, pulmonary function instrument and pulmonary ventilation testing unit |
| CN111811681A (en) * | 2020-02-27 | 2020-10-23 | 重庆大学 | Air-breathing type fiber bragg grating total temperature probe and measuring system thereof |
| CN112304375A (en) * | 2020-10-27 | 2021-02-02 | 浙江大学 | Ultrasonic flow sensor and flow measurement method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1893992B1 (en) * | 2005-06-17 | 2011-09-21 | Maquet Critical Care AB | Provision of a gas measurement chamber for ultrasound measurements with reduced temperature influence |
| US20080051661A1 (en) * | 2006-08-28 | 2008-02-28 | Kabushiki Kaisha Toshiba | Ultrasonic diagnostic apparatus and ultrasonic diagnostic method |
| US8273033B2 (en) * | 2006-12-21 | 2012-09-25 | Ric Investments, Llc | Temperature compensation of a respiratory gas sensor |
-
2021
- 2021-07-30 CN CN202110868691.7A patent/CN113558659B/en active Active
Patent Citations (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH078472A (en) * | 1993-06-23 | 1995-01-13 | Nippondenso Co Ltd | Breathing amount measurement device |
| JPH07178086A (en) * | 1993-12-21 | 1995-07-18 | Toshiba Corp | Method for ultrasonic diagnosis and system therefor |
| JPH11318860A (en) * | 1998-05-20 | 1999-11-24 | Anima Kk | Oxygen consumption meter |
| CN1343107A (en) * | 1999-03-12 | 2002-04-03 | 梅德拉股份有限公司 | Controlling contrast enhanced imaging procedures |
| WO2002024070A1 (en) * | 2000-09-20 | 2002-03-28 | Peter Ganshorn | Device for rapidly determining the diffusion capacity of a lung |
| CN1395678A (en) * | 2000-10-10 | 2003-02-05 | 松下电器产业株式会社 | Flow measuring device |
| CN1492735A (en) * | 2001-02-23 | 2004-04-28 | ������¡���ˡ��������� | Non invasive measurements of chemical substances |
| CN101326427A (en) * | 2005-12-08 | 2008-12-17 | 大陆汽车有限责任公司 | Device for determining a mass flow |
| CN102027386A (en) * | 2008-01-09 | 2011-04-20 | 海浪科技有限公司 | Nonlinear elastic imaging with two-frequency elastic pulse complexes |
| CN101354394A (en) * | 2008-09-08 | 2009-01-28 | 无锡尚沃生物科技有限公司 | Expiration nitric oxide detection device |
| CN202078295U (en) * | 2010-06-01 | 2011-12-21 | 谭伟 | Near-infrared laser system for inspecting deep vein thrombosis |
| CA2836278A1 (en) * | 2010-10-21 | 2012-04-26 | Yoram Palti | Measuring pulmonary blood pressure using transthoracic pulmonary doppler ultrasound |
| CN103630174A (en) * | 2013-12-07 | 2014-03-12 | 重庆前卫科技集团有限公司 | Flow measuring method of ultrasonic flow meter |
| CN103989488A (en) * | 2014-04-09 | 2014-08-20 | 河南迈松医用设备制造有限公司 | Wide-range ultrasonic pulmonary function instrument and calculation method thereof |
| CN103948401A (en) * | 2014-05-20 | 2014-07-30 | 夏云 | Portable lung function instrument and lung function detection method |
| CN204190393U (en) * | 2014-10-21 | 2015-03-04 | 重庆路之生科技有限责任公司 | The meticulous reactive power compensator of low pressure |
| CN105581796A (en) * | 2014-11-10 | 2016-05-18 | ndd医药技术股份有限公司 | Breathing tube for use in ultrasonic flow measurement systems |
| CN104605857A (en) * | 2015-02-12 | 2015-05-13 | 上海朔茂网络科技有限公司 | Lung function measuring method |
| CN105698884A (en) * | 2016-03-07 | 2016-06-22 | 上海电气自动化设计研究所有限公司 | Improved measurement method of time difference type ultrasonic flow meter |
| CN109640827A (en) * | 2016-03-23 | 2019-04-16 | 皇家飞利浦有限公司 | Method and apparatus for improving the measurement of velocity of blood flow |
| CN109937000A (en) * | 2016-10-20 | 2019-06-25 | 海尔斯安普有限责任公司 | Portable spirometer |
| CN106422638A (en) * | 2016-12-05 | 2017-02-22 | 王睿智 | Air haze purification device |
| CN107242874A (en) * | 2017-05-26 | 2017-10-13 | 台州亿联健医疗科技有限公司 | Flow sensor, spirometer and application for lung function tests |
| WO2019102384A1 (en) * | 2017-11-22 | 2019-05-31 | Fisher & Paykel Healthcare Limited | Respiratory rate monitoring for respiratory flow therapy systems |
| CN109839855A (en) * | 2017-11-27 | 2019-06-04 | 张旭 | A kind of control circuit of ultrasound lung function instrument |
| CN209548088U (en) * | 2018-12-28 | 2019-10-29 | 重庆安酷科技有限公司 | Pulmonary function detection cart |
| CN109637662A (en) * | 2019-02-14 | 2019-04-16 | 广东工业大学 | A kind of pulmonary function detection and the method and system of data statistics |
| CN110169786A (en) * | 2019-05-21 | 2019-08-27 | 广州畅呼医疗器械有限公司 | A kind of ultrasonic drive circuit, driving method and ultrasonic lung function instrument |
| CN110200632A (en) * | 2019-07-01 | 2019-09-06 | 武汉市澄心小匠科技有限公司 | A kind of Portable lung function detecting instrument |
| CN111811681A (en) * | 2020-02-27 | 2020-10-23 | 重庆大学 | Air-breathing type fiber bragg grating total temperature probe and measuring system thereof |
| CN111329482A (en) * | 2020-04-03 | 2020-06-26 | 夏云 | Pulmonary function instrument testing head, pulmonary function instrument and pulmonary ventilation testing unit |
| CN112304375A (en) * | 2020-10-27 | 2021-02-02 | 浙江大学 | Ultrasonic flow sensor and flow measurement method thereof |
Non-Patent Citations (8)
| Title |
|---|
| Richards, Michael S.Kripfgans, Oliver D..MEAN VOLUME FLOW ESTIMATION IN PULSATILE FLOW CONDITIONS.《ULTRASOUND IN MEDICINE AND BIOLOGY》.2009,第第35卷卷(第第35卷期),全文. * |
| Sun, Zhenxing；Zhang, Ziming；Liu, Jie.Lung Ultrasound Score as a Predictor of Mortality in Patients With COVID-19.《FRONTIERS IN CARDIOVASCULAR MEDICINE》.2021,第第8卷卷全文. * |
| 刘佳,李扬,王睿,田小平..不同辅助方式在前列腺穿刺活检术中的应用进展.《智慧健康》.2019,第第5卷卷(第第5卷期),全文. * |
| 张志敏.深呼吸加压超声扫查对提高胰腺显示率的作用.《现代诊断与治疗》.2013,第第24卷卷(第第24卷期),全文. * |
| 朱圣兵.半夏白术天麻汤加减治疗交感神经型颈椎病疗效观察.《新中医》.2017,第第49卷卷(第第49卷期),全文. * |
| 沈翔,慈书平,顾克荣,周子英,仝威.睡眠呼吸暂停患者颈动脉超声多普勒参数分析.《中国医学影像技术》.1998,(第undefined期),全文. * |
| 沙仁高娃,王睿.宫腔镜联合超声检查在异常子宫出血中的应用.《延边医学》.2015,(第undefined期),全文. * |
| 高向民,欧艳秋,吴勇.完全性肺静脉异位引流患者术后流速和吻合口大小与早中期预后的关系.《岭南心血管病杂志》.第第22卷卷(第第22卷期),全文. * |
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