CN100348149C - Nonlinear fetal heart rate surveillance instrument - Google Patents

Abstract

The present invention relates to a nonlinear fetal heart rate monitor which belongs to the technical field of a medical care device. The present invention uses an ultrasonic Doppler sensor to take the heart sound signals of fetuses, then uses a fetal heart rate signal extraction device to extract the envelope of audio signals in the audio signals of the fetal heart sound, then transfers square signals obtained by the fetal heart rate signal extraction device to an A/D interface card PC6360 to finish the A/D conversion of the fetal heart rate signals, and then transfers the converted fetal heart rate signals to a nonlinear computer analysis processor, wherein the nonlinear computer analysis processor is provided with a human-computer interaction interface compiled by VB high-level languages and a working interface of nonlinear kinetic analysis software package compiled by VC high-level languages, and an analysis software in the nonlinear kinetic analysis software package is compiled by TC high-level languages, so that doctors can make out diagnostic suggestion for advising clinics. With the advantages of low price and favorable market perspective, the present invention can be widely used in nationwide hospitals above county levels, the clinical medicine teaching in colleges and universities and the technical field of scientific research.

Description

Nonlinear fetal heart rate surveillance instrument

Technical field

The invention belongs to the health care technology field, relate to a kind of health-monitoring instrument; International Patent classificating number: A61B5/024.

Background technology

The variation of fetal heart frequency can reflect fetus in the intravital different health status of mother, can diagnose out the various diseases of fetus by detecting fetal heart frequency.That is to say that fetal heart rate signal is loaded with the information of abundant sign foetus health situation.In traditional medical science detected, the doctor adopted traditional fetal heart frequency monitor, and fetal heart frequency is recorded on the paper tape, and the doctor relies on the clinical experience diagnosing fetal disease and the foetus health situation of accumulation for many years.Because of the difference between doctor's individuality, diagnose no unified objective criterion.

The inventor adopts growth promoter of Nonlinear Dynamics research fetus and the relation between preceding instantaneous fetal heart frequency of childbirth and the neonate health.In the past, the recording curve of what fetal heart frequency showed that fetus (comprising puerperal neonate) was healthy or weary oxygen or near dead, the doctor can only judge there is not unified objective criterion by rule of thumb.The nonlinear fetal heart rate surveillance instrument of the present invention's development can write down the instantaneous heart rate of fetus, and according to the nonlinear kinetics principle, adopts phase space reconfiguration, correlation dimension, maximum lipschitz exponent, power spectrum, correlation function, methods such as approximate entropy are from a plurality of Perspective Analysis foetus health situations.Can do qualitative and quantitative statistical analysis and classification, for perinatal care and eugenic, good child-rearing provide scientific basis.

Summary of the invention

The purpose of this invention is to provide a kind of nonlinear fetal heart rate surveillance instrument, it can not only show, write down and store the heart rate signal of fetus by computer real-time, and can adopt nonlinear dynamic analysis method (correlation dimension, maximum lipschitz exponent, approximate entropy, power spectrum, auto-correlation function and cross-correlation function) express fetus in the intravital different health status of mother.

The present invention adopts the ultrasonic doppler pick off to extract the cardiechema signals of fetus, utilize the fetal heart rate signal extractor from the audio signal of fetal heart sound, to extract the envelope of audio signal then, and the envelope of audio signal is converted to corresponding with it square-wave signal, makes a square-wave signal corresponding with a fetal heartbeat; To pass to PC6360 mould/number incoming interface card by the square-wave signal that the fetal heart rate signal extractor obtains, finish the mould/number conversion of fetal heart rate signal, and pass to NONLINEAR CALCULATION machine analysis processor, calculate instantaneous fetal heart frequency by NONLINEAR CALCULATION machine analysis processor according to the interval of adjacent twice square wave, NONLINEAR CALCULATION machine analysis processor further can be finished the data of instantaneous fetal heart rate signal and the real-time demonstration of figure, reappear, and the storage of data, the nonlinear kinetics calculation of parameter part of NONLINEAR CALCULATION machine analysis processor can be calculated the correlation dimension of fetal heart rate signal, maximum lipschitz exponent, entropy, complexity, power spectrum, auto-correlation function and cross-correlation function.

The doctor can make diagnostic recommendations according to the different distributions interval of nonlinear characteristic amount and the corresponding relation of different foetus health situations.

Technical solution of the present invention:

As shown in Figure 1, at first extract the cardiechema signals of fetus by the ultrasonic doppler pick off, utilize fetal heart rate signal extractor (its circuit theory diagrams are shown in Fig. 2-8) from the audio signal of fetal heart sound, to extract the envelope (shown in Fig. 2-7) of audio signal, make that the envelope of a fetal heart sound signal is corresponding with a fetal heartbeat, behind zero balancing circuit (Fig. 8), the envelope that makes a cardiechema signals is corresponding to a square-wave signal; The square-wave signal that the fetal heart rate signal extractor is obtained passes to PC6360 mould/number interface card, finish the mould/number conversion of fetal heart rate signal and pass to NONLINEAR CALCULATION machine analysis processor, calculate data and the pictorial display that instantaneous fetal heart frequency further can be finished instantaneous fetal heart rate signal simultaneously by NONLINEAR CALCULATION machine analysis processor according to the interval of adjacent twice square wave, reappear, and the storage of data, NONLINEAR CALCULATION machine analysis processor can calculate the correlation dimension of fetal heart rate signal, maximum lipschitz exponent, entropy, complexity, power spectrum, auto-correlation function and cross-correlation function.The doctor can utilize the different distributions of nonlinear kinetics parameter of Fetal Instantaneous Heart Rate signal and the corresponding relation of foetus health situation, provides diagnostic recommendations.

Related description about circuit theory diagrams:

At first extract the fetal heart sound signal by the ultrasonic multispectral probe of reining in, what connect subsequently is by resistor R ₁, capacitor C ₁And the cable follower (as shown in Figure 2) of operational amplifier μ A741 composition, wherein resistor R ₁Can adopt rheostat, what be connected with the pin 6 of operational amplifier μ A741 is by resistor R ₂, R ₃, R ₄, R ₅With the amplifying circuit (as shown in Figure 2) of operational amplifier μ A741 composition, wherein resistor R ₅Can adopt rheostat, the amplification of amplifier is adjustable within the specific limits like this.Operational amplifier μ A741 pin of chip 6 is connected with the pin 9 of multiplier MC1495.By resistance R ₁₃, R ₁₄, R ₁₅, R ₁₆, Zener diode D ₁, D ₂And the square-wave generator (as shown in Figure 3) of operational amplifier μ A741 composition, operational amplifier μ A741 pin of chip 6 is connected with the pin 4 of multiplier (as shown in Figure 4) MC1495.The pin 1 of multiplier MC1495 passes through resistor R ₈Be connected with+15V power supply, pin 2 passes through resistor R ₁₀Be connected with+15V power supply, pin 3 passes through resistor R ₇Ground connection is connected to resistor R between pin 5 and the pin 6 ₁₂, pin 7 connects-the 15V power supply, and pin 8 ground connection are connected with resistor R between pin 10 and the pin 11 ₁₁, pin 12 ground connection, pin 13 passes through resistor R ₆Be connected with ground, pin 14 passes through resistor R ₉Be connected pin 14 direct ground connection simultaneously, pin 2 and by resistor R with+15V power supply ₁₇, R ₁₉, R ₂₁, R ₂₃, R ₂₅, R ₂₇, R ₂₉, R ₃₁, capacitor C ₃, C ₅, C ₇, C ₉, C ₁₁, C ₁₂, C ₁₅, C ₁₄And the mid frequency that 4 operational amplifier μ A741 chips are formed is the 8 rank chebyshev low-pass filters (as shown in Figure 5) of 5Hz, the 3rd the operational amplifier μ A741 chip pin 6 of wave filter with by resistor R ₁₈, R ₂₀, R ₂₂, R ₂₄, R ₂₆, R ₂₈, R ₃₀, R ₃₂, capacitor C ₄, C ₆, C ₈, C ₁₀, C ₂₂, C ₁₃, C ₂₅, C ₁₆And the mid frequency that 4 operational amplifier μ A741 chips are formed is the 8 rank chebyshev low-pass filters (as shown in Figure 6) of 5Hz, the 3rd the operational amplifier μ A741 chip pin 6 of wave filter with by capacitor C ₁₇, resistor R ₃₃The zero crossing circuitry of forming (as shown in Figure 7) connects, zero crossing circuitry subsequently with by resistor R ₃₄, R ₃₅, R ₃₆, R ₃₇, R ₃₈, R ₃₉, R ₄₀, R ₄₁, capacitor C ₈, C ₉, C ₁₀, C ₁₁, C ₂₃, C ₂₄, C ₂₆, C ₂₇And the mid frequency that 4 operational amplifier μ A741 chips are formed is the 8 rank chebyshev low-pass filters (as shown in Figure 7) of 5Hz, the 3rd μ A741 pin of chip 6 of wave filter and resistor R ₄₂, R ₄₃, R ₄₄And the amplifier (as shown in Figure 8) formed of operational amplifier μ A741 chip, the pin 6 of amplifier is connected with the pin 3 of operational amplifier μ A741, pin 2 ground connection of this operational amplifier μ A741, pin 6 and by resistor R ₄₅, R ₄₆, diode D ₃, D ₄,, capacitor C ₂₈The voltage limiter circuit of forming (as shown in Figure 8), resistor R ₄₆, capacitor C ₂₈The junction, link with the digital input channel of PC6360 mould/number interface card.

By the ultrasonic multispectral fetal heart sound signal that probe collects of reining in, at first pass through the cable follower, be amplifier then, then cardiechema signals and 95Hz square-wave signal carry out coherent detection, signal behind the coherent detection, continuously by 28 rank chebyshev low-pass filters, then through zero crossing circuitry, again through 8 rank chebyshev low-pass filters, then signal is amplified, cross zero balancing then, the voltage amplitude limit is after the digital input channel of PC6360 mould/number interface card inserts NONLINEAR CALCULATION machine analysis processor.Use NONLINEAR CALCULATION machine analysis processor to carry out date processing and analysis at last.

Described NONLINEAR CALCULATION machine analysis processor is equipped with work circle by the nonlinear dynamic analysis software kit of the human-computer interaction interface of VB high-level language establishment and the establishment of VC high-level language, and use TC high-level language has been worked out the analysis software in the nonlinear dynamic analysis software kit.

Analysis software of the present invention is by two-dimensional phase Space Reconstruction program unit, the power spectrum program unit, the time series program unit, the approximate entropy program unit, the correlation function program unit, the correlation dimension program unit, maximum lipschitz exponent unit program and vc boundary element program are formed, at first, open this program of vc interface, what be presented in ours in front is a dialog box, 7 programs is arranged: two-dimensional phase Space Reconstruction program in the drop-down menu of his the inside, the power spectrum program, the time series program, approximate entropy program, correlation function program, the correlation dimension program, maximum lipschitz exponent program.Correlation function program in these 7 program the insides of operation is a parameter for correlation dimension and maximum lipschitz exponent; So, before operation correlation dimension program and maximum lipschitz exponent program, be to move the correlation function program earlier;

Data doctor according to the said procedure gained can analyze fetal heart frequency exactly, the health status of analytical judgment fetus;

The flow process of following each program of division:

The interface program that vc++ weaves into begins to build an engineering.In Dialog, add a dialog box then.Add control (drop-down menu, three buttons, paste bitmap) on Dialog, in the content that the CmyDlg class is added 8 variablees and its representative, respectively top control is added responder, program just is through with like this;

The program flow diagram of approximate entropy is at first opened data file to be analyzed, and it can calculate the total total number of data of this file then; Then, read data number N to be analyzed from file, calculate standard deviation: σ, calculate: 0.2* σ → L, input embeds dimension m, because algorithm requirement itself is 2.The phase space of reconstruct m n dimensional vector n, the distance that calculates any two points in this space is paid count less than the number of L, so approximate entropy is exactly:

Approximate entropy: $\left(\mathrm{ApEn}\right)\underset{N\→\∝}{\lim }[{\mathrm{\Φ}}^m\left(L\right)-{\mathrm{\Φ}}^{m+1}\left(L\right)]$ And ${\mathrm{\Φ}}^m\left(L\right)=\frac{1}{N-M+1}\underset{i=1}{\overset{N-m+1}{\mathrm{\Σ}}}\ln C_i^m\left(L\right),C_i^m\left(L\right)=\frac{1}{N-m}*\mathrm{count});$

The program flow diagram of correlation dimension is at first opened data file to be analyzed, and it can calculate the total total number of data of this file then; Then, read data number n to be analyzed from file and be put into another data file 1, import initial dimension m then, the step-length mk of growth and retardation k.When m＜md enters Do statement, in this circulation the inside, at first want the phase space (its algorithm is identical with the flow chart of two-dimensional phase Space Reconstruction) of reconstruct m n dimensional vector n to be put into two data files 2 respectively, in 3, obtain depositing in the file 4 of counting in the file 2,3 apart from d, just go into next circulation then, input start radius A, the radius step-length B of growth, initialization s is 0.Just go into circulation when r＜C: sense data and r ratio from file 4, if d＜r, s just adds 1, is just to add 0 greater than r.Can obtain one group of lnC (r) and ln (r) like this under this condition of r＜C, the figure that draws then, the slope of this figure are exactly the dimension D of requirement.M adds mk and can obtain a dimension D again then, can obtain one group like this; (jaggies in the flow chart and straight line do not intersect)

The power spectrum program flow diagram is at first opened data file to be analyzed, and it can calculate the total total number of data of this file then; Then, reading data number n to be analyzed from file is put into another data file 1.Be put in the data file 2 as auto-correlation function with this n number, it has been exactly the figure of power spectrum that the data that the data in the reuse 2 obtain as Fourier transform are drawn; (autocorrelative algorithm is exactly the algorithm of the flow chart of correlation function program)

The program flow diagram of correlation function is at first opened data file to be analyzed, and it can calculate the total total number of data of this file then; Then, reading data number N to be analyzed from file is put into the data file 1.Input Nb value (wanting the number of picture point), the m assignment is 0, (N-Nb) composes and gives T.If m＜Nb enters outer circulation, be summation variable s assignment 0 then.Enter internal recycle, j is the internal recycle variable, and initial value is 0, and j＜T. calculates two retardations and multiplies each other, and revests s with s and product summation, and internal recycle is over and just can obtains a s value.Draw as horizontal, vertical coordinate with m and s.(if calculate from time series reading is exactly self correlation, if be exactly cross-correlation from two different time series readings.First minimum of figure is exactly a time delay)

The program flow diagram of two-dimensional phase Space Reconstruction, start program can be inquired the data file name that you are to be analyzed, can calculate total what data of this file then; Then, read you from this file and want the data number n analyzed, then it is put into again in the data file 1,, embed dimension initial value m=2 with the input delay variate-value, retardation k, initializing variable b is 0, calculates number a little; Then be two Do statements.At first, i is outer circulation, and j is that circulation, and reading is paid variable y from file 1, works as i, when j, k, b, m satisfy condition shown in the block diagram, and just y is write in the file 2 during b=0, when b=1, just write in the file 3, so just can not draw with the data in 2,3 are non-as horizontal vertical coordinate.(top jaggies and straight line do not intersect)

The program flow diagram of temporal sequence, this is the program flow diagram of a calculating time delay amount, at first opens data file to be analyzed, it can calculate the total total number of data of this file then.Then, input starting point vb puts ve finally, calculates: the ve-vb → n that always counts, can draw with that, and abscissa is a natural number, vertical coordinate is the number that reads out from data file.

The program flow diagram of maximum lipschitz exponent is at first opened data file to be analyzed, and it can calculate the total total number of data of this file then.Then, read data number n to be analyzed from file and be put into another data file 1, import initial dimension m=mb then, the step-length mp of growth and retardation k.When m＜md enters Do statement, in this circulation the inside, at first want the phase space of reconstruct m n dimensional vector n and it is put in the data file 2, selected 1 j (＜n-(m-1) * k), find out its nearest neighbor point J ' then, and calculate it apart from d (0), through τ calculate once more after the time this 2 apart from d (τ), draw d (τ) with the change curve of τ and to ask its slope value be exactly maximum lipschitz exponent value, once more m is added that step-length mp Do statement place calculates.

Good effect of the present invention is:

(1) clinicing aspect: can instruct the clinician to pass through the observation of instantaneous fetal heart frequency and the health status of analytical judgment fetus (clinician is according to the baseline and the direct judgement of the fluctuation foetus health thereof of fetal heart frequency monitoring at present) according to the nonlinear kinetics principle;

(2) master plan fertility: have very profound significance with research to improving the population health situation, improving the health of the people by analysis to the foetus health situation.

(3) the rank lattice are cheap, and market prospect is good, can hospital above county level promote the use of in the whole nation through secondary development.

Description of drawings

Fig. 1 is the whole schematic block diagram of the present invention;

Fig. 2 is an amplifying circuit of the present invention;

Fig. 3 is a square-wave generator of the present invention;

Fig. 4 is a multiplier of the present invention;

Fig. 5 is a low-pass filtering of the present invention;

Fig. 6 is a low-pass filtering of the present invention;

Fig. 7 is zero passage of the present invention and low-pass filtering;

Fig. 8 crosses zero balancing and amplitude limit for the present invention;

Fig. 9 is an operation sequence sketch map of the present invention;

The interface program that Figure 10 weaves into for vc++ of the present invention

Figure 11 is the program flow diagram of approximate entropy of the present invention;

Figure 12 is the program flow diagram of correlation function of the present invention;

Figure 13 is a power spectrum program flow diagram of the present invention;

Figure 14 is the program flow diagram of time delay of the present invention;

Figure 15 is the program flow diagram of two-dimensional phase Space Reconstruction of the present invention;

Figure 16 is the program flow diagram of correlation dimension of the present invention;

Figure 17 is the program flow diagram of the maximum lipschitz exponent of the present invention.

The specific embodiment

Embodiment:

The present invention is made up of four parts:

1. ultrasonic doppler pick off;

2. the fetal heart rate signal extractor of forming by analog circuit and digital circuit;

3. the fetal heart rate signal extractor connects with PC6360 mould/number interface card, finishes the mould/number conversion of fetal heart rate signal;

4. NONLINEAR CALCULATION machine analysis processor;

Further narrate the present invention below in conjunction with accompanying drawing, described fetal heart sound signal is gathered by the ultrasonic multispectral probe of reining in, and what connect subsequently is by resistor R ₁, capacitor C ₁And the cable follower (as shown in Figure 2) of operational amplifier μ A741 composition, wherein resistor R ₁Can adopt variable resistance, what be connected with the pin 6 of the operational amplifier μ A741 of cable follower is by resistor R ₂, R ₃, R ₄, R ₅With the amplifying circuit (as shown in Figure 2) of operational amplifier μ A741 composition, wherein R ₅Can use variable resistance, the amplification of amplifier is adjustable within the specific limits like this; Cardiechema signals is imported the pin 9 of multiplier MC1495 through after amplifying, and cardiechema signals and square-wave signal carry out coherent detection; By resistor R ₁₃, R ₁₄, R ₁₅, R ₁₆, Zener diode D ₁, D ₂And the square-wave generator (as shown in Figure 3) of operational amplifier μ A741 composition, the pin 6 of operational amplifier μ A741 is connected with the pin 4 of multiplier MC1495 (as shown in Figure 4); The pin 1 of multiplier MC1495 passes through resistor R ₈Be connected with+15V power supply, pin 2 passes through resistor R ₁₀Be connected with+15V power supply, pin 3 passes through resistor R ₇Ground connection is connected to resistor R between pin 5 and the pin 6 ₁₂, pin 7 connects-the 15V power supply, and pin 8 ground connection are connected with resistor R between pin 10 and the pin 11 ₁₁, pin 12 ground connection, pin 13 passes through resistor R ₆Be connected with ground, pin 14 passes through resistor R ₉Be connected with+15V power supply, pin 14 direct ground connection obtain the cardiechema signals envelope behind the coherent detection simultaneously; Pass through by resistor R subsequently ₁₇, R ₁₉, R ₂₁, R ₂₃, R ₂₅, R ₂₇, R ₂₉, R ₃₁, capacitor C ₃, C ₅, C ₇, C ₉, C ₁₁, C ₁₂, C ₁₅, C ₁₄And the mid frequency that 4 operational amplifier μ A741 form is the 8 rank chebyshev low-pass filters (as shown in Figure 5) of 5Hz, the pin 6 of the 3rd operational amplifier μ A741 of wave filter with by resistor R ₁₈, R ₂₀, R ₂₂, R ₂₄, R ₂₆, R ₂₈, R ₃₀, R ₃₂, capacitor C ₄, C ₆, C ₈, C ₁₀, C ₂₂, C ₁₃,, C ₂₅, C ₁₆The mid frequency that reaches 4 operational amplifier μ A741 chips compositions is the 8 rank chebyshev low-pass filters (as shown in Figure 6) of 5Hz, and signal is by pin 6 outputs of the 3rd operational amplifier, through obtaining intact hear sounds envelope after twice low-pass filtering; Subsequently signal is carried out zero passage, remove flip-flop; Zero crossing circuitry (as shown in Figure 7) is by capacitor C ₁₇, resistor R ₃₃Form; Subsequently with by resistor R ₃₄, R ₃₅, R ₃₆, R ₃₇, R ₃₈, R ₃₉, R ₄₀, R ₄₁, capacitor C ₈, C ₉, C ₁₀, C ₁₁, C ₂₃, C ₂₄, C ₂₆, C ₂₇The mid frequency that reaches 4 operational amplifier μ A741 compositions is that the 8 rank chebyshev low-pass filters 9 (as shown in Figure 7) of 5Hz connect, and removes the interference of being introduced by zero passage, pin 6 and the resistor R of the 3rd operational amplifier μ A741 of wave filter ₄₂, R ₄₃, R ₄₄And the amplifier (as shown in Figure 8) that operational amplifier μ A741 forms, signal is amplified; Obtain the square-wave signal of hear sounds envelope after the signal process zero balancing (as shown in Figure 8) after the amplification, through voltage limiter circuit (as shown in Figure 8), remove the negative loop in the signal, obtain the TTL ripple, link with the digital input channel of PC6360 mould/number interface card subsequently and insert NONLINEAR CALCULATION machine analysis processor.By the interval of NONLINEAR CALCULATION machine analysis processor, calculate instantaneous fetal heart frequency according to adjacent twice square wave of record.

Aforementioned operational amplifier can replace with the operational amplifier of high integration such as NE532.

The circuit elements device parameters:

R ₁＝200kΩ；R ₂＝10kΩ；R ₃＝20k?Ω；R ₄＝20kΩ；R ₅＝10kΩ；C ₁＝120pF；R ₆＝12kΩ；R ₇＝12kΩ；

R ₈＝3kΩ；

R ₉＝R ₁₀＝20kΩ；R ₁₁＝R ₁₂＝10kΩ；R ₁₃＝R ₁₄＝20kΩ；

R ₁₅＝48.8kΩ；R ₁₆＝473kΩ；

R ₁₇＝R ₁₉＝R ₂₁＝R ₂₃＝R ₂₅＝R ₂₇＝R ₂₉＝R ₃₁＝100KΩ；

C ₃＝0.15μF；C ₅＝0.033μF；C ₇＝2.2μF；C ₉＝0.15μF；

C ₁₁＝0.047μF；C ₁₂＝0.047μF；C ₁₅＝0.01μF；C ₁₄＝10μF；

R ₁₈＝R ₂₀＝R ₂₂＝R ₂₄＝R ₂₆＝R ₂₈＝R ₃₀＝R ₃₂＝100kΩ；

C ₄＝0.15μF；C ₆＝0.033μF；C ₈＝2.2μF；C ₁₀＝0.15μF；C ₂₂＝0.047μF；C ₁₃＝0.047μF；C ₂₅＝10μF；C ₁₆＝0.01μF；C ₁₇＝0.1μF；R ₃₃＝410Ω；

R ₃₄＝R ₃₅＝R ₃₆＝R ₃₇＝R ₃₈＝R ₃₉＝R ₄₀＝R ₄₁＝100kΩ；

C ₈＝0.15μF；C ₉＝0.033μF；C ₁₀＝2.2μF；C ₁₁＝0.15μF；C ₂₃＝0.047μF；C ₂₄＝0.047μF；C ₂₆＝10μF；C ₂₇＝0.01μF；

R ₄₂＝5kΩ；R ₄₃＝7.5kΩ；R ₄₄＝15kΩ；R ₄₅＝470kΩ；R ₄₆＝1.5kΩ；C ₂₈＝0.01μF。

Wherein resistor all adopts fixed carbon resister, capacitor C ₁₄, C ₂₅, C ₂₆Be electrochemical capacitor, all the other electric capacity are ceramic condenser, diode D ₁, D ₂, D ₃, D ₄Be the 5.5V Zener diode, amplifier is operational amplifier μ A741.We also can for example use operational amplifier NE5532 to wait substitution operation amplifier μ A741 with the higher operational amplifier of integrated level.

The operation interface of nonlinear fetal heart rate surveillance instrument, be with the establishment of Visual-Basic high-level language, form by three parts: at first be one and eject the interface, be a patient information input interface then, can import patient's name, age, case number and pregnant all numbers, be working interface at last.

Working interface can be realized following function:

(1) the real-time demonstration and the record of instantaneous fetal heart rate signal, 40-240bpm;

(2) alarm indicator of instantaneous fetal heart rate signal promptly is lower than 120bpm when instantaneous fetal heart frequency value, or is higher than 160bpm, and when continuing 20 seconds on the interface amber light or red light bright;

(3) has the data-storing function;

(4) has the reproduction capability of data and figure.

Nonlinear fetal heart rate surveillance instrument uses the VC high-level language to work out the working interface of nonlinear dynamic analysis software kit, and uses the TC high-level language to work out calculation procedure; Can calculate the correlation dimension of fetal heart rate signal, maximum lipschitz exponent, approximate entropy, power spectrum, auto-correlation function and cross-correlation function.Utilize the corresponding relation of nonlinear kinetics parameter and different foetus health situations, provide diagnostic recommendations.

Operating process of the present invention: ultrasonic Doppler probe is positioned over anemia of pregnant woman's abdominal part, extract the fetal heart sound signal by ultrasonic Doppler probe, to pass to the fetal heart rate signal extractor of forming by analog circuit and digital circuit by the fetal heart sound signal that the ultrasonic doppler sensor probe extracts, the fetal heart rate signal extractor is connected with PC6360 mould/number interface card, finish the mould/number conversion of fetal heart rate signal, go out instantaneous fetal heart frequency by COMPUTER CALCULATION, and be presented on the computer display.Computer was stored the Fetal Instantaneous Heart Rate data automatically after detection finished, and can do nonlinear dynamic analysis to instantaneous fetal heart frequency data by the program that the nonlinear kinetics software kit provides at last.At first, open this program of vc interface, what be presented in ours in front is a dialog box, 7 programs is arranged: two-dimensional phase Space Reconstruction program in the drop-down menu of his the inside, the power spectrum program, time series program, approximate entropy program, the correlation function program, correlation dimension program, maximum lipschitz exponent program.Correlation function program in these 7 program the insides of operation is a parameter for correlation dimension and maximum lipschitz exponent; So, before operation correlation dimension program and maximum lipschitz exponent program, be to move the correlation function program earlier;

Data doctor according to the said procedure gained can analyze fetal heart frequency exactly, the health status of analytical judgment fetus.

Claims (1)

1, a kind of nonlinear fetal heart rate surveillance instrument is made up of ultrasonic doppler pick off, fetal heart rate signal extractor, A/D converter and NONLINEAR CALCULATION machine analysis processor, it is characterized in that:

Adopt the ultrasonic doppler pick off to extract the cardiechema signals of fetus, utilize the fetal heart rate signal extractor from the audio signal of fetal heart sound, to extract the envelope of audio signal then, and the envelope of audio signal is converted to corresponding with it square-wave signal, makes a square-wave signal corresponding with a fetal heartbeat; To pass to PC6360 mould/number interface card by the square-wave signal that the fetal heart rate signal extractor obtains, finish the mould/number conversion of fetal heart rate signal, and pass to NONLINEAR CALCULATION machine analysis processor, calculate instantaneous fetal heart frequency by NONLINEAR CALCULATION machine analysis processor according to the interval of adjacent twice square wave, NONLINEAR CALCULATION machine analysis processor further can be finished the data of instantaneous fetal heart rate signal and real-time demonstration, the reproduction of figure, and the storage of data;

Described NONLINEAR CALCULATION machine analysis processor is equipped with the working interface by the nonlinear dynamic analysis software unit of the human-computer interaction interface of VB high-level language establishment and the establishment of VC high-level language, use TC high-level language has been worked out the analysis software in the nonlinear dynamic analysis software kit, this analysis software comprises two-dimensional phase Space Reconstruction program unit, the power spectrum program unit, the time series program unit, the approximate entropy program unit, the correlation function program unit, the correlation dimension program unit, maximum lipschitz exponent program unit; Wherein the correlation function program unit is a parameter of correlation dimension program unit and maximum lipschitz exponent program unit;

Described two-dimensional phase Space Reconstruction program unit, the power spectrum program unit, the correlation function program unit, the time series program unit is selected one as required, or a plurality of, or full choosing.

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