CN104688192B - Audio sound source based on difference frequency ultrasound is produced and air flue characteristic test method and system - Google Patents
Audio sound source based on difference frequency ultrasound is produced and air flue characteristic test method and system Download PDFInfo
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- CN104688192B CN104688192B CN201510149424.9A CN201510149424A CN104688192B CN 104688192 B CN104688192 B CN 104688192B CN 201510149424 A CN201510149424 A CN 201510149424A CN 104688192 B CN104688192 B CN 104688192B
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- A—HUMAN NECESSITIES
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- 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
- A61B8/4444—Constructional features of the ultrasonic, sonic or infrasonic diagnostic device related to the probe
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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
- A61B8/52—Devices using data or image processing specially adapted for diagnosis using ultrasonic, sonic or infrasonic waves
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Abstract
Produced and air flue characteristic test method and system the invention discloses a kind of audio sound source based on difference frequency ultrasound, the audio sound source generation system includes：The signal generator module of the different square-wave signal of two frequencies of generation；The signal amplification module being amplified to square-wave signal, to improve the driving voltage of ultrasonic probe, the effective acoustic pressure and effective acoustic power of the final audio sound source for producing of enhancing；Two centre frequency identical broad band low frequency ultrasonic probes, respectively by amplifying after square-wave signal drive and produce the two different ultrasonic waves of row, the controllable audio sound source of frequency is produced by nonlinear interaction.It is based on the gaseous path's characteristics method of testing without intrusion audio sound source：By the use of the ultrasonic audio sound source for producing of difference frequency as the input signal of air flue, while the audio output signal at air passage outlet end is measured, can be without the transmission characteristic for intrusively measuring air flue by signal frequency analysis.
Description
【Technical field】
The invention belongs to biological information detection field, and in particular to a kind of to be produced without the audio sound source for invading and in organism
Gaseous path's characteristics enter the method and application system of Mobile state measurement.
【Background technology】
Air flue is the tube chamber system that many animals and the mankind have, and it has ten during respiratory and sound are produced
Divide important function.In birds, air flue includes tracheae, syrinx, oral cavity, the first half and beak of esophagus；And in mammal, air flue
Tracheae and upper sound channel two parts are generally comprised, upper sound channel is divided into cavum laryngis, pharyngeal cavity, oral cavity and nasal cavity.
During sound is produced, the Main Function of air flue is sympathetic response, is produced by being modulated to sound source with difference
The sound of tone color.When sound source encourages air flue, each component is selectively transmitted by sound channel in sound source spectrum, i.e. some harmonic component quilts
Strengthen, and some are weakened, the final frequency characteristic for determining sound.The main structure institute by air flue of the Frequency transfer of air flue
Determine, and air passage structure is different and different with sounding.By taking voice generation as an example, mainly by changing tongue, lip, tooth
The position of the vocal organs such as tooth, hard palate, soft palate changes air passage structure, so as to produce different voices.Therefore, gaseous path's characteristics change
The measurement for having material impact, gaseous path's characteristics for the generation of sound produces process and sound timbre feature for understanding sound
Etc. significant.
The method of measurement gaseous path's characteristics mainly includes following several at present：First, Linear prediction analysis method be apply compared with
A kind of wide speech analysis method, directly can directly extract track characteristics from voice signal by Resonance Peak Analysis.So
And, closure mutually could obtain preferable result during the method needs synchronous ElectroglottographicWaveform signal, larger by influence of noise.The
Two, air passage structure can be imaged using nmr imaging technique, then air flue transmission characteristic is obtained by calculating.It is this
Although method can obtain more clearly air passage structure information, expensive, and calculating process is difficult to imitate true
Air flue transmittance process, simultaneously because the limitation of image taking speed is difficult to obtain dynamic gaseous path's characteristics.3rd, ultrasonic electronic hard palate
Figure is a kind of method of oral cavity structure in utilization ultrasonic imaging technique measurement voiced process, so that using sound channel in the Structure Calculation
Transmission function.The method speed, but the area information in a certain section in oral cavity can only be obtained, it is difficult to reflect whole air flue
Overall permanence, has some limitations.
For the measurement of air ducting system characteristic, most original and accurate method are exactly the input and output time letter according to system
Count to determine.Although using sensors such as microphones output signal directly can be gathered in air flue output end (lip), however, from
It is external that to directly applying in air flue, known and controllable input signal is very difficult.
If it is possible to apply known and controllable audio sound source into air flue as excitation from outside without what is invaded
Signal, then the output signal of air flue is measured by real-time synchronization, it becomes possible to realize the measurement to gaseous path's characteristics.
【The content of the invention】
In order to sound source applies in solving the problems, such as gaseous path's characteristics measurement, the present invention utilizes the non-linear phase interaction of ultrasonic wave
With a kind of audio sound source based on difference frequency ultrasound of proposition is produced and air flue characteristic test method and system.Particular content includes：
A kind of audio sound source generation system based on difference frequency ultrasound, including：Signal generator module：Produce two frequency differences
Square-wave signal；Signal amplification module：The square-wave signal that signal generator module is produced is amplified, to improve ultrasonic probe
Driving voltage, the effective acoustic pressure and effective acoustic power of the final audio sound source for producing of enhancing；Ultrasonic probe：Including two centers frequently
Rate identical broad band low frequency ultrasonic transducer, respectively by amplifying after square-wave signal drive and produce the two different ultrasonic waves of row, lead to
Cross nonlinear interaction and produce the controllable audio sound source of frequency.
The frequency of the square-wave signal that the signal generator module is produced is 37~43kHz.
The difference on the frequency of the different square-wave signal of two frequencies that the signal generator module is produced is f, wherein, the scope of f
It is 1~5000Hz.
The signal generator module is provided with timer, the different side of two frequencies by chip microcontroller in single-chip microcomputer
Ripple signal passes through Timer Controlling and output.
The audio frequency of source scope that the audio sound source generation system based on difference frequency ultrasound is produced is 1~5000Hz.
The centre frequency of the broad band low frequency ultrasonic transducer is 40kHz, and impedance is 500 Ω, and sensitivity is 103dB, most
Big driving voltage is 150Vp-p, and 108dB is reached in the sound pressure level of 30cm range measurements ultrasonic probe generation.
A kind of audio sound source generating method based on difference frequency ultrasound, it is the side of f that signal generator module produces two difference on the frequencies
Ripple signal, two square-wave signals are amplified, while driving two ultrasonic transducers of ultrasonic probe, produce two row frequencies not
Same ultrasonic wave, the audio sound sources that frequency is f are produced by the interaction of two ultrasonic waves is final.
It is a kind of based on without invade audio sound source gaseous path's characteristics method of testing, using difference frequency ultrasound produce audio sound source make
It is the input signal of air flue, while the audio signal at air passage outlet end is measured as air flue output signal, by signal frequency point
Analysis finally gives the transmission characteristic of air flue.
Gaseous path's characteristics test can use two kinds of different audio sound source forcing modes：Single frequency excitation and swept frequency excitation；It is right
In single frequency excitation, the generation and excitation, direct measurement system of single-frequency sound source are directly realized by setting frequency control parameters f
Output signal simultaneously calculates gaseous path's characteristics；For swept frequency excitation, it is necessary to set the scope and speed of frequency sweep, wherein, peak frequency model
It is 1~5000Hz to enclose, and sweep velocity is 1~5000Hz/s.
Compared with prior art, the present invention at least has the advantages that：
In a system of the invention, the frequency of the main two row square-wave signals exported by signal generator module of the frequency of audio sound source
Rate difference is determined, specifically then by setting a frequency parameter f (f>0Hz) realize the FREQUENCY CONTROL to audio sound source.For
One f value of determination, signal generator module can generate two different square-wave signals of frequency, and the difference of its frequency is f Hz, is amplified
Drive two ultrasonic transducers simultaneously afterwards, produce frequency to believe for the audio of f Hz by the interaction of two ultrasonic waves is final
Number.Based on the present invention, the audio frequency of source scope that can be produced is 1~5000Hz, and FREQUENCY CONTROL precision is less than 1Hz.This
Outward, present system can be realized controlling the acoustic pressure of audio sound source by control signal amplification module, its purpose is to logical
Cross raising signal intensity and improve signal to noise ratio, finally improve certainty of measurement.
The present invention produces the known sound source of controllable precise in air flue, and sound channel is directly calculated by measuring exports audio signal
Feature is more accurate compared to the result that existing indirect measurement method is obtained；Additionally, the inventive method measuring speed is fast, compared to existing
There is method, be obtained in that the result of sound channel dynamic change.
【Brief description of the drawings】
Fig. 1 technical scheme overall schematics
The audio sound source that Fig. 2 is based on difference frequency ultrasound produces hardware system figure
The program flow diagram of Fig. 3 signal generator modules
Fig. 4 is based on the audio sound source waveform figure of difference frequency ultrasound
The audio sound source waveform figure of Fig. 5 1~2000Hz swept frequency excitations and time frequency analysis figure
【Specific embodiment】
1. overall technology and embodiment
As shown in figure 1, being overall technology involved in the present invention and embodiment schematic diagram, mainly include super based on difference frequency
The audio sound source generation system of sound, control method and gaseous path's characteristics measure three aspects.First, present invention design realizes base
Hardware system is produced in the audio sound source of difference frequency ultrasound, can be the square wave of f Hz according to FREQUENCY CONTROL requirement two difference frequencies of generation
Signal, drives two low frequency ultrasound transducers to produce the different ultrasonic wave of two row frequencies by amplifying.Secondly, in measurement process,
Ultrasonic probe is at an angle of and is positioned over outside air ducting system so that two detecting head surfaces are with target sound source position in approximately the same plane
It is interior.After system starts, there is nonlinear interaction in two row ultrasonic waves because frequency is different, so as to produce the difference that frequency is f Hz
Frequency signal.In present system by FREQUENCY CONTROL f in the range of 1~5000Hz, it is f Hz that frequency can be produced in air flue
Audio sound source.Finally, by the audio measuring apparatus such as microphone, air ducting system under audio sound source forcing can be obtained
Output signal.Meanwhile, audio sound source is the known signal of control synthesis, therefore, in known input signal and the feelings of output signal
Under condition, the characteristic response function of sound channel can be realized by frequency analysis.
2. the audio sound source based on difference frequency ultrasound produces hardware system
Present system hardware components mainly include signal generator module, signal amplification module, ultrasonic probe module three
The part being linked in sequence.Signal generator module exists mainly for generation of the different square-wave signal of two frequencies, its frequency range
In the range of 37~43kHz, and two frequencies of square-wave signal can be by manually carrying out precise control.Signal generator module output
Square-wave signal is directly entered signal amplification module, and it mainly realizes amplifying the control of square-wave signal, in order to improve super
The driving voltage of sonic probe, so as to strengthen the effective acoustic pressure and effective acoustic power of the audio sound source of final generation.Ultrasonic probe mould
Block includes that two centre frequencies are the broad band low frequency ultrasonic transducer of 40kHz, respectively by amplifying after square-wave signal drive and produce
The different ultrasonic wave of raw two row frequencies, and the controllable audio sound source of frequency can be produced by nonlinear interaction.Such as Fig. 2 institutes
Show, be that the audio sound source based on difference frequency ultrasound produces hardware system figure.Wherein, signal generator module is using inside c8051f330
Timer produces two square-wave signals of different frequency of the frequency between 37~43kHz.Signal amplification module can be by square wave
Signal is amplified to 30V or so, then drives two ultrasonic probes to produce the ultrasonic wave of two row different frequencies using the signal.
1) signal generator module
Signal generator module is by c8051f330 chip microcontrollers in present system, by the internal timing of the single-chip microcomputer
Device 2,3 is controlled and the output different square waves of two frequencies respectively.Fig. 3 shows the program flow diagram of the signal generator module,
Can realize that fixed frequency output exports two kinds of different signal modes with frequency sweep.Exported for fixed frequency, it is only necessary to fixed
When device 2 and the frequency of timer 3 set, timer 2 is exported by IDAC ports, and timer 3 passes through port P0.2
Output low and high level.For frequency sweep output, timer 2,3 frequency are made according to certain speed linear change using cyclic program.
When the system is realized, by setting the frequency of the timer 2 linear decrease in the range of 37.5~40kHz, the frequency of timer 3 exists
Linear increment in the range of 40~42.5kHz, can realize the audio sound source control of the optional frequency section frequency sweep in the range of 1~5000Hz
System output.
2) signal amplification module
Signal amplification module uses the OPA454 amplifiers of TI companies in present system, and it has high voltage and high current
Feature, its effect is exactly to be amplified the square-wave signal that NE555 timers are produced.The partial power using DC voltage-stabilizing-
Bipolar power supply is powered, and is ± 32V.Circuit diagram such as Fig. 2 can show that amplifier section employs 200k Ω potentiometers so that
The multiplication factor of the amplifying circuit is 1~21, and can be with real-time regulation multiplication factor so that output voltage is maximum and does not lose
Very.It is 5V that front end signal produces the square-wave signal high level that part produces, and low level is 0V, by amplifying, high level is amplified
To 30V, low level is still 0V.
3) ultrasonic probe
The ultrasonic probe that present system is used is that the XZR-40RSB low frequencies of Yi Biao science and technology (Shenzhen) Co., Ltd production surpass
Sonic transducer.Its centre frequency is 40kHz, and impedance is 500 Ω, and sensitivity is 103dB, and maximum drive voltage is 150Vp-p.
Size is 14 × H9mm of φ.108dB is reached in the sound pressure level (SPL) of 30cm range measurements ultrasonic probe generation.
3. the audio sound source based on difference frequency ultrasound is produced and control
The present invention utilizes the nonlinear interaction (difference frequency characteristic) between different frequency ultrasonic wave, by producing two row frequencies not
Same and adjustable ultrasonic signal, realizes the generation and control of the controllable audio sound source of frequency.In present system, audio sound source
The difference on the frequency of the main two row square-wave signals exported by signal generator module of frequency determined, specifically then by one frequency of setting
Rate parameter f (f>0Hz) realize the FREQUENCY CONTROL to audio sound source.For a f value for determination, signal generator module can be generated
Two frequencies are respectively the square-wave signal of (40000-f/2) Hz and (40000+f/2) Hz, and the difference of its frequency is f Hz, after amplification
Two ultrasonic transducers are driven simultaneously, are the audio signal of f Hz by the final generation frequency of the interaction of two ultrasonic waves.
Based on hardware system of the invention, the audio frequency of source scope that can be produced is 1~5000Hz, and FREQUENCY CONTROL precision is less than
1Hz.Additionally, in present system, can realize controlling the acoustic pressure of audio sound source by control signal amplification module, its purpose
It is to improve signal to noise ratio by improving signal intensity, finally improving certainty of measurement.As shown in Figure 4, it is shown that based on difference frequency
The signal waveform of the different frequency audio sound source that ultrasound is produced.For the hardware components of present system, can join according to frequency
Number f produces control ultrasonic probe to launch the different ultrasonic wave of two row frequencies, and under nonlinear interaction, producing has multi-frequency
The waveform of component.As shown in the upper figures of Fig. 4, when frequency parameter f is 1Hz, i.e. the frequency of two row ultrasonic waves be respectively 39999.5Hz and
During 40000.5Hz, black lines show the waveform that two row ultrasound wave interaction is formed, and its frequency component includes each ultrasound
The frequency of ripple, and its difference frequency (1Hz) and and frequency (80kHz).Red curve shows the difference frequency component of its 1Hz in figure, it is seen then that
The difference frequency signal precision controlling that present system can be realized reaches at least 1Hz.Additionally, Fig. 4 also show being surveyed using microphone
100Hz the and 500Hz audio sound source waveforms for measuring, are the single periodic signal of frequency, and waveform stabilization, its amplitude is mainly led to
Amplification module is crossed to be controlled.
4. the audio sound source forcing mode that gaseous path's characteristics are measured
Input signal of the present invention by the use of the ultrasonic audio sound source for producing of difference frequency as air flue, while measuring air passage outlet end
Audio signal as air flue output signal, the transmission characteristic of air flue is finally given by signal frequency analysis.During measurement, by two
Individual ultrasonic probe is coupled as outside with tissue, it is ensured that two positions of ultrasonic probe apply position same flat with target sound source
In face.In measurement process, the audio sound source of given frequency is produced by controlling frequency parameter, while measuring the sound at air passage outlet
Frequency signal.Present system realizes two kinds of different audio sound source applying modes, and respectively single-frequency applies and frequency sweep is applied
Plus.Single-frequency applies to produce single-frequency sound source, and frequency sweep applies to change the frequency values of sound source according to fixed rate, real
The frequency response measurement of present 1~5000Hz scopes.
Based on hardware system of the invention, the measurement of gaseous path's characteristics can use two kinds of different audio sound source forcing sides
Formula, respectively single frequency excitation and swept frequency excitation.For single frequency excitation, directly single frequency is realized by setting frequency control parameters f
The generation of rate sound source simultaneously calculates gaseous path's characteristics with excitation, direct measurement system output signal.Swept, it is necessary to set for swept frequency excitation
The scope and speed of frequency, maximum frequency range is 1~5000Hz in present system, and sweep velocity can need according to experiment
It is configured between 1~5000Hz/s.As shown in figure 5, the audio signal ripple of the 1~2000Hz frequency sweeps applying for the system realization
Shape figure and time frequency analysis figure, its sweep velocity are 1000Hz/s.
Single frequency excitation and swept frequency excitation can be respectively used to the measurement of static characteristic and dynamic characteristic, and either single-frequency is still swept
Frequency is encouraged, and air passage structure keeps certain stability within a certain period of time in being required for ensureing measurement process.For mankind's sounding
For process, because air passage structure changes relatively slow, while subject can independently be controlled, therefore, it is possible to meet measurement
It is required that.For swept frequency excitation mode, sweep velocity needs to be set according to requirement of experiment, and sweep velocity is too fast to be likely to occur measurement knot
The deviation of fruit, therefore, the selection principle of sweep velocity be it is as fast as possible on the premise of certainty of measurement is ensured, certainty of measurement it is inclined
From can be with single frequency excitation result as foundation.
Audio sound source based on difference frequency ultrasound proposed by the invention is produced and the method and system of air flue feature measurement has
Have the following advantages：
1) present system directly produces sound source with measuring method without invasive inside air flue, can be with minimum degree
Interference air ducting system, it is ensured that the accuracy of measurement；
2) audio sound source is accurate and controllable, it is possible to achieve the measurement of single-frequency and frequency sweep both of which, meets air flue special
Property dynamic measurement；
3) the method and system can expand to other and direct measurement and cannot need outside without invading the inside gas that applies
The practical application of road system performance measurement.
Claims (8)
1. it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：Including following part：
Signal generator module：The square-wave signal for producing two frequencies different；
Signal amplification module：The square-wave signal that signal generator module is produced is amplified, to improve the driving electricity of ultrasonic probe
Pressure, the effective acoustic pressure and effective acoustic power of the final audio sound source for producing of enhancing；
Ultrasonic probe：Including two centre frequency identical broad band low frequency ultrasonic transducers, respectively by amplifying after square-wave signal
The ultrasonic wave for producing two row different is driven, the controllable audio sound source of frequency is produced by nonlinear interaction；
During test, two ultrasonic probes are placed in and outside are coupled with organizing, it is ensured that the position of two ultrasonic probes and target sound source
Apply position in the same plane, by the use of the ultrasonic audio sound source for producing of difference frequency as the input signal of air flue, while measuring gas
The audio signal of the road port of export finally gives the transmission characteristic of air flue by signal frequency analysis as air flue output signal.
2. it is according to claim 1 it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：The letter
The frequency of the square-wave signal that number generation module is produced is 37 ~ 43 kHz.
3. it is according to claim 1 it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：The letter
The difference on the frequency of the different square-wave signal of two frequencies that number generation module is produced is f, wherein, the scope of f is 1 ~ 5000 Hz.
4. it is according to claim 1 it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：The letter
Number generation module is provided with timer by chip microcontroller in single-chip microcomputer, the different square-wave signals of two frequencies are by timing
Device is controlled and exported.
5. it is according to claim 1 it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：The base
The audio frequency of source scope produced in the audio sound source generation system of difference frequency ultrasound is 1 ~ 5000 Hz.
6. it is according to claim 1 it is a kind of based on difference frequency ultrasound audio sound source generation system, it is characterised in that：It is described low
The centre frequency of frequency wide band ultrasonic transducer is 40 kHz, and impedance is 500 Ω, and sensitivity is 103dB, and maximum drive voltage is
150Vp-p, in the sound pressure level of 30cm range measurements ultrasonic probe generation（SPL）Reach 108dB.
7. it is a kind of based on system described in claim 1 based on without invade audio sound source gaseous path's characteristics method of testing, its feature
It is：By the use of the ultrasonic audio sound source for producing of difference frequency as the input signal of air flue, while measuring the audio letter at air passage outlet end
Number as air flue output signal, the transmission characteristic of air flue is finally given by signal frequency analysis.
8. according to claim 7 based on without the gaseous path's characteristics method of testing for invading audio sound source, it is characterised in that：Air flue
Characteristic test can use two kinds of different audio sound source forcing modes：Single frequency excitation and swept frequency excitation；For single frequency excitation, directly
Connected and generation and excitation that frequency control parameters realize single-frequency sound source were set, direct measurement system output signal was simultaneously calculated
Gaseous path's characteristics；For swept frequency excitation, it is necessary to set the scope and speed of frequency sweep, wherein, maximum frequency range is 1 ~ 5000 Hz,
Sweep velocity is 1 ~ 5000 Hz/s.
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| WO2017127739A1 (en) * | 2016-01-20 | 2017-07-27 | Soniphi Llc | Frequency analysis feedback systems and methods |
| CN112556836A (en) * | 2020-12-18 | 2021-03-26 | 浙江省计量科学研究院 | Method and device for measuring noise of pulmonary whistle |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1229542A (en) * | 1996-07-17 | 1999-09-22 | 美国技术公司 | Acoustic heterodyne device and method |
| CN2645798Y (en) * | 2003-09-02 | 2004-10-06 | 张大威 | Ultrasonic treatment apparatus |
| CN101203062A (en) * | 2007-07-20 | 2008-06-18 | 徐利梅 | Method for numeral sound signal processing and digital type sound frequency directional loudspeaker |
| CN101984555A (en) * | 2010-11-10 | 2011-03-09 | 瑞声声学科技(深圳)有限公司 | Parametric array audio play system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU5902099A (en) * | 1998-09-24 | 2000-04-10 | American Technology Corporation | Parametric loudspeaker with electro-acoustical diaphragm transducer |
| WO2011055286A1 (en) * | 2009-11-03 | 2011-05-12 | Koninklijke Philips Electronics N.V. | Apparatus for measuring a level of a specific gas in exhaled breath |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1229542A (en) * | 1996-07-17 | 1999-09-22 | 美国技术公司 | Acoustic heterodyne device and method |
| CN2645798Y (en) * | 2003-09-02 | 2004-10-06 | 张大威 | Ultrasonic treatment apparatus |
| CN101203062A (en) * | 2007-07-20 | 2008-06-18 | 徐利梅 | Method for numeral sound signal processing and digital type sound frequency directional loudspeaker |
| CN101984555A (en) * | 2010-11-10 | 2011-03-09 | 瑞声声学科技(深圳)有限公司 | Parametric array audio play system |
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