The specific embodiment
As Fig. 1~shown in Figure 17, monitor of stages of labor device of the present invention comprises:
Be used to measure three first sonac, second sonac, the 3rd sonacs that the triangularity that is positioned over puerpera's abdominal part of puerpera's cervical dilatation and fetal head position is arranged with transmission-receiving function, the 4th sonac that is positioned over puerpera's cervix uteri mouth both sides respectively, the 5th sonac with receiving function, the 6th sonac with fetus head that is positioned over the puerpera of receiving function, wherein said first sonac, second sonac are positioned near puerpera's the anterior superior iliac spine, and the 3rd sonac is positioned at puerpera's pubis middle and lower part; Be positioned over the pressure transducer that is used to measure uterine pressure of the outer stomach wall of puerpera; Be positioned over the ultrasonic Doppler transducer that is used to measure the fetal rhythm rate of puerpera's abdominal part; Be used for according to first sonac, second sonac, the 3rd sonac, the 4th sonac, the 5th sonac, the resulting ultrasonic signal of the 6th sonac and parameter drives and demodulation process and each sonac of obtaining being correlated with between the ultrasonic signal of distance drive and the demodulation process device; Be used for the output signal and the parameter of ultrasonic signal driving and demodulation process device are carried out computing and obtained cervical dilatation and fetal head position CALCULATION OF PARAMETERS blood processor; Be used for uterine contraction pressure parameter with pressure transducer and be converted to the signal of telecommunication go forward side by side the uterine contraction pressure detecting and the conversion processing unit of line number mould conversion process; Ultrasonic this ultrasound wave that involves that is used for sending according to ultrasonic Doppler transducer enters the ultrasonic signal that reflected after the tissue to obtain fetal rhythm rate parameter go forward side by side the ultrasound-driven detection of fetal rhythm rate and the digital-to-analogue conversion and the accountant of conversion of line number mould and the computing of fetal rhythm rate; Be used for that uterine contraction pressure parameter, fetal rhythm rate parameter that the cervical dilatation of calculation processing apparatus output and fetal head position parameter and uterine contraction pressure detecting and conversion processing unit and the ultrasound-driven detection of fetal rhythm rate and digital-to-analogue conversion and accountant are exported respectively be sent to that background terminal is handled and show continuously and obtain including cervical dilatation and background process and demonstration printing equipment that fetal head position changes and uterine contraction pressure and fetal rhythm rate change stages of labor curve is also diagnosed according to this and printed.
The position relation of wherein above-mentioned six pick offs as shown in Figures 1 and 2, wherein A, B, C, E, F, H represent the first, second, third, fourth, the 5th and the 6th sonac respectively, the present invention mainly is exactly by being that referential comes measurements and calculations to go out cervical dilatation and fetal head position from the plane that A, B, C formed, the present invention can be reduced to as shown in Figure 3 model when lying on the back (be equivalent to the puerpera model) for this reason, wherein A, B are the abdominal part pick off, place near the anterior superior iliac spine, C is the abdominal part pick off also, places the pubis middle and lower part.E, F are the uterus internal sensor, and H is the fetal head pick off.With ABC is reference frame, calculates the relative coordinate of E, F, H, then can calculate cervical dilatation and fetal head position.Wherein to be example, illustrate how to calculate relative coordinate earlier.
As shown in Figure 4, ABC is leg-of-mutton three summits,
For with
Equidirectional unit vector, then
Order
For perpendicular to
With
Unit vector, then
Then
Component unit orthogonal basis (is initial point with B).
Then
If
Then have:
Solve:
If 1 F in space is respectively a to the distance of 3 of ABC
1, b
1, c
1,
If
Then
,
Solve:
Therefore, if F is respectively FA, FB, FC to the distance of 3 of ABC, E is respectively EA, EB, EC to the distance of 3 of ABC, is reference plane with ABC, the relative coordinate (X of E, F
E, Y
E, Z
E), (X
F, Y
F, Z
F) as follows:
By 2 range formulas in space, can get cervical dilatation:
Suppose that triangle is made up of two abdominal part sensors A, B and fetal sensor H, definition θ is the angle of BH and BA, like this
The distance of fetal head pick off H and two abdominal part sensors A B is:
h=BHsinθ
Fetal head position determines that by calculating fetal head and the planar distance of ischial spine as shown in Figure 5, like this, the beginning of program (after pick off is fixed to fetus head) obstetrician imports the estimated value of ischial spine plane and AB line distance.This value is thought a baseline, and all measured values all have a fixed biasing, and like this, fetal head position calculates according to following formula:
is the distance between ischial spine plane and AB pick off.
As long as, just can measure cervical dilatation and fetal head position so measure the distance of AB, BC, AC, EA, EB, EC, FA, FB, FC, HA, HB, HC.Therefore, the main task of system is exactly how accurately to measure the distance of AB, BC, AC, EA, EB, EC, FA, FB, FC, HA, HB, HC.And the basic skills that supersonic sounding adopted has two kinds: ultrasound Doppler's method, flight time measurement method.Ultrasound Doppler's method utilizes Doppler effect work.When ultrasound wave incides on the running target object, ultrasound wave is reflected by target.With respect to incidence wave generation is proportional to the frequency shift (FS) of target object speed according to doppler principle reflection wave frequency, measure the frequency shift (FS) of echo, obtain the movement velocity of target object, if the original position of known target object, movement velocity is carried out integration to the time, just can obtain the distance of target object and ultrasonic transducer.Ultrasonic sound Doppler method exists an important disadvantages, if target object is static or its motion is very slow, it can't carry out range measurement.
The flight time measurement method realizes range measurement at interval by measurement (pulse wave signal or continuous wave signal) flight time between launch point and acceptance point that transmits.Therefore tested distance can be expressed as:
s=vt
Wherein, s-testing distance
The v-ultrasonic propagation velocity
The t-flight time
The ultrasonic sound wave that is higher than the human auditory system scope that is meant typically refers to the dither mechanical wave that frequency is higher than 20kHz, and the supersonic frequency that is applied to medical science is generally between 1MHz to tens MHz.
Ultrasonic operating frequency determine mainly based on following some
(1) if the Capability Requirement of range finding is very big, sonic propagation loss just increases relatively, because medium is to square being directly proportional of the absorption of sound wave and frequency of sound wave, and for reducing the propagation loss of sound wave, just must the reduction operating frequency.
(2) operating frequency is high more, concerning the transducer of same size, the directivity of pick off is sharp-pointed more, it is accurate more to measure the barrier complex surface, and wavelength is short, size resolution height, and " details " easy identification is clear, therefore from measuring complex barrier thing surface and certainty of measurement, operating frequency requires to improve.
(3) from the sensor design angle, operating frequency is low more, and size sensor is just big more, makes and install just difficult more.
(4) from the medical science aspect, ultrasonic mainly being divided in clinical practice aspect two of the Clinics and Practices: ultrasonic diagnosis is adopted is higher-frequency (how more than 2M) and the ultrasound waves of the low sound intensity, high frequency can improve the resolution to tissue, frequency is high more, ultrasonic attenuation must be fast more, and its penetration capacity is poor more, and ultrasonic therapeutic is adopted is lower frequency (usually less than 1MHz) and ultrasound wave than high sound intensity, low frequency ultrasound increases the penetrance to tissue, and less to the human influence.
In sum,, pick off little owing to maximum measurement range among the present invention will have certain directivity, and can not produce too big side effect to human body, thereby the selection supersonic frequency is 1MHz.Calculate cervical dilatation and fetal head position, according to foregoing ultrasonic triangulation principle, the distance on AB, BC, AC, AE, BE, CE, AF, BF, CF, AH, these 12 limits of BH, CH be must measure, cervical dilatation (EF) and fetal head position (HS) just can be calculated according to following formula.
Wherein α is an empirical value, because the ABH plane is at a slight tilt, gradient adds that by abdominal part sensing station and the decision of puerpera's pelvis empirical value α purpose is the influence that is caused for the compensating for tilt plane, improves accuracy.
is the distance between ischial spine plane and AB pick off.
Be that example illustrates length how to measure AE below with AE, other 11 limits (AB, BC, AC, BE, CE, AF, BF, CF, AH, BH, CH) use the same method and can measure.
Utilize microprocessor controls to be fixed in the sonac A emission ultrasound wave of abdominal part, controller picks up counting simultaneously, when the sonac E that is fixed on cervix uteri receives ultrasonic signal, stops timing, then the distance of AE:
AE=λvt
Wherein λ is a modifying factor, because everyone physiological situation is incomplete same, sound spread speed in vivo is incomplete same.So add a proportionality constant correction.
V is hyperacoustic spread speed, if do not consider skeleton, then greatly about 1350 to 1800 metre per second (m/s)s, and the average speed in soft tissue is generally 1540 metre per second (m/s)s to ultrasound wave in the spread speed of human body.
T is for launching ultrasound wave to receiving hyperacoustic time difference.In order to improve degree of accuracy, its meansigma methods is got in continuous measurement 5 times.
Be positioned over first ultrasonic Doppler transducer that is used to measure uterine pressure of the outer stomach wall of puerpera;
Be positioned over the puerpera---second ultrasonic Doppler transducer that is used to measure the fetal rhythm rate; Owing to run into the object of a motion when ultrasonic signal Doppler effect will take place, change has taken place in the frequency of ultrasonic of its reflection, has comprised a large amount of movable information of this moving object in this frequency displacement Δ f.
By ultrasonic duty, doppler system can be divided into CW and PW in time domain.CW is the successive ultrasound wave that transmits and receives, and is commonly referred to the continous way ultrasonic doppler.PW is the emission of pulse discontinuous, and time delay, gating received, and was commonly referred to pulsating ultrasound Doppler.Continous way Doppler requires to use two sensors, one group is used for launching continuously ultrasound wave, another group is used for constantly receiving echo-signal, because ultrasonic continuous transmits and receives, echo-signal has comprised the movable information of all the various moving objects on the ultrasound-transmissive passage, and because emission and accept the two sensors placement of staggering, can not obtain uniform sound field covers, when capturing ability is all not ideal enough because these two key factors cause continous way Doppler's noise, has designed pulsating ultrasound Doppler at these problems people.
The probe of pulsed mode Doppler only has one group of pick off, be that emitter serves as receptor again, solved the uneven problem of continuous ultrasound ripple Doppler sound field, ultrasonic probe sends pulse signal to the reflection at a distance of the L place, ultrasonic with speed C towards surveying the body motion, the echo of reflection returns with same spread speed, the ultrasonic back of sending is reflected back receptor when time t=2L/C, piezoelectricity is converted into the signal of telecommunication, probe is launched pulse signal next time then, in two subpulses emission gap, probe receives echo-signal.
Under certain spread speed, gap length between the pulse determined instrument at detection range, the 1/RPF reciprocal that the umber of pulse that per second is launched is called pulse recurrence frequency (PULS repetition frequency RPF) PRF is the time of twice pulse interval, according to heart of fetus existing position in parent, the RPF of fetal heart monitoring system is generally about 3K.
Because pulsating ultrasound Doppler is to receive selectively to the echo-signal of different depth, some useless movable informations are left out, signal to noise ratio is greatly improved, simultaneously owing to the lasting time of ultrasound emission is very short, sound field is even, so compare spatiotemporal ultrasonic mean power with continuous ultrasound Doppler much lower, ultrasonic energy significantly reduces the potential risk of fetus.
Utilize pulsating ultrasound ripple principle, sonac is transformed into ultrasound echo signal and has the movable information high frequency electrical signal, this high frequency electrical signal is carried out high frequency to be amplified, frequency discrimination, low frequency amplifies, a series of processing acquisition such as filtering and the on all four fetal heart sound signal of fetus heart beating, ask envelope to obtain more regular fetus heart beating signal to fetal heart sound signal, and the fetus heart beating signal is carried out A/D change, fetus heart beating signal behind the digitized is carried out trying to achieve with autocorrelative signal processing technology behind the digital filtering cycle of signal, by the further number of times that obtains the per minute fetal heartbeat of cycle, i.e. fetal rhythm rate.
Along with uterine contraction, outer stomach wall the anemia of pregnant woman shows the pressure variation simultaneously, anemia of pregnant woman's outer stomach wall fix by bandage a pressure transducer just can record easily outside the pressure of stomach wall change, though record the true pressure that pressure is not pregnant woman uterus, but and relative intensity and persistent period that pregnant woman uterus shrinks are height correlations, by the situation that this straightforward procedure is measured, the record uterine pressure changes, verified clinically by analyzing the relation between this uterine contraction curve and the fetal rhythm rate curve, can obtain the health condition of fetus rapidly.
Be used for according to first sonac, second sonac, the 3rd sonac, the 4th sonac, the 5th sonac, the resulting ultrasonic signal of the 6th sonac and parameter drives and demodulation process and each sonac of obtaining being correlated with between the ultrasonic signal of distance drive and the demodulation process device; This moment is as Fig. 7~shown in Figure 9,
Range finding ultrasonic emitting and driving circuit device are:
With NAND gate 74HC00 and pulse generator of crystal oscillator design, frequency is 1MHz, two NAND gate of U2D and U2B also are in the same place, increase driving force, capacitor C 24 and inductance L 4 are formed a frequency selection circuit, behind the square wave process LC loop, become sine wave, on the one hand filtering high-frequency harmonic, have the frequency stabilization effect on the other hand.ENA is controlled by microprocessor, and when ENA was high level, the emission ultrasound wave was not launched ultrasound wave during low level.Ultrasound wave reception/the demodulation principle of wherein finding range is:
Ultrasonic reception electrolysis demodulation circuit is made up of amplifying circuit and time to peak point testing circuit two parts.
The ultrasonic probe ultrasonic waves transmitted is the constant amplitude cosine impulse ripple with certain width, can distort when it is propagated in medium, through the echo-signal after the amplification filtering.
The moment when in general, surpassing the threshold value of our regulation with the amplitude of received signal is as stopping timing signal.When testing distance changes, the amplitude of receiving circuit output signal just changes, the nearly output signal amplitude of distance is bigger, just might surpass the threshold value of regulation this moment in second all amplitudes of echo-signal, and then send and stop timing signal, when distance was far away, the output signal amplitude was less, the 3rd week of echo-signal (even the 4th week), amplitude just might surpass the threshold value of regulation, and sent and stop timing signal.Theoretically, the mid point that stops the echo-signal that timing signal should be after amplification filtering sends, because the existence of threshold value, and in fact stop timing signal is a certain constantly after mid point to send, and the moment of sending (time Detection Point) changes with variable in distance, and the variation of this " time Detection Point " has just produced the error of range measurement.In sum, characteristics at echo-signal, adopt the time to peak point to detect method, the signal processing of this method is at first will be through amplifying, filtered echo-signal is carried out the linear envelope detection, then the output signal of detection being carried out differential handles, at last zero crossings being carried out in the output of peaker detects, can obtain the time to peak of echo-signal, this moment, no matter tested distance was far and near, the time Detection Point is all on the summit of echo-signal, promptly at the peak point of echo signal envelope line, and it does not change with the variation of tested distance with respect to the position of mid point.As seen, deduct a set time when needing only, just can eliminate top said measurement error sound.
Ultrasound wave reception/demodulator circuit the device of for this reason finding range is the circuit arrangement that adopts as shown in Figure 8, U1A and C3, R4, R5 form pre-amplification circuit, pre-amplification circuit has realized the linear amplification of small-signal having higher input impedance and lower output impedance with in-phase amplifier.R8, R9, R10, C6, C7, U1B constitute band filter, because ultrasonic received signal is faint and contain noise, signal to noise ratio is little, so receiving circuit has designed second-order bandpass filter, select suitable circuit parameter, make mid frequency, passband gain, these several indexs of quality factor of band filter reach suitable value.D1, C2, R3 form linear evelope detector, the peaker of being made up of C4, R7, U1D carries out the differential processing to the output signal of detection then, by LM311 zero crossings being carried out in the output of peaker at last detects, can obtain the time to peak of echo-signal, this moment, no matter tested distance was far and near, the time Detection Point is all on the summit, and promptly at the peak point of echo signal envelope line, and it does not change with the variation of tested distance with respect to the position of mid point.As seen, deduct a set time when needing only, just can eliminate top said measurement error sound.
Cervical dilatation and fetal head position calculate and are mainly finished by the ultrasonic transceiver module of Single-chip Controlling, single-chip microcomputer produces an enable signal and gives the ultrasound emission module, when enabling the number of making for high level, then launches ultrasound wave, when enable signal is low level, do not launch ultrasound wave.It is suitable that emission ultrasonic pulse number should be selected, and pulse number energy at most is big, but pulse number is many, and the blind area is also big.Get 5 pulses among the present invention, because piezoelectric ceramic wafer has certain vibration inertia, after it receives signal, to just reach capacity through several cycles, when finishing when transmitting in addition, wafer also keeps the remained shock in several cycles, so received signal has tens wave heads.
The present invention has 12 drive tests apart from passage, adopts time-sharing work, the circulation range finding.Circuit as shown in Figure 9, ENA produces an enable signal, control ultrasonic sending module A and send signal, opening intervalometer simultaneously picks up counting, wait for that sonac E receives signal, stop timing, calculate the distance of A E, in like manner, calculate the distance of AB, BC, AC, BE, CE, AF, BF, CF, AH, BH, CH.Then
Then cervical dilatation EF and fetal head position HS can following formula calculate:
After calculating EH and HS, the data communication module circuit of transmitting scriptures is passed to the control terminal PC on backstage.
This moment, above-mentioned operation principle and the process of utilizing pressure transducer and ultrasonic Doppler transducer to detect uterine contraction pressure and fetal rhythm rate respectively was as follows shown in Figure 10~15:
Obtain ultrasonic signal, source of ultrasound signal and ultrasound-driven circuit must be arranged, as shown in figure 10, U2 is a high speed MCU, and U2 is from the mutual reverse source of ultrasound signal of 1,18 two pin output 2MHz; Signal source is controlled by internal processes, and with the pulse recurrence frequency (PRF) of 3KHz, each pulsed beams is the ultrasonic pulse bundle of the 2MHz of 50uS, produces and transmit at B simultaneously to be used for the reference signal of demodulation with the frequency homophase, in C generation time gating signal.
The impulse ultrasound signal source by the field manage T9, T10 driving transformer T5 boosts, and through the driving signal of telecommunication of T5 after boosting, is added on the piezoelectric ultrasonic transducer, the signal of telecommunication is converted into ultrasonic signal.
For impulse ultrasound Doppler's ultrasonic transducer be transmitting transducer also be receiving transducer, at intermittence of transmitted pulse ultrasonic beam not is exactly the time that transducer receives ultrasound echo signal, in this period, the ultrasonic signal that reflects from heart of fetus takes place ± Δ f frequency displacement, this ultrasound wave that reflects carries out the acoustic-electric conversion through ultrasonic transducer, be converted into the signal of telecommunication of 2MHz ± Δ f, certainly the fundamental frequency of the relative 2MHz of frequency displacement of Δ f is a very little variable, so the mid frequency f that our frequency-selecting is amplified
0Still be selected in 2MHz; f
0± Δ f imports from TP1, pass through the series connection selecting frequency filtering network of forming by L1, C1, C2 as shown in figure 11, carry out preliminary frequency-selective filtering, tunable capacitor C2 can finely tune the center frequency point of frequency-selective filtering, the resonance point that makes frequency-selective network is 2MHz, the effect of R1 is to regulate the frequency-selective network damped coefficient, makes circuit working more stable.T1 is low noise preposition amplification field effect transistor, constitutes preposition frequency-selecting by T1, L2, C4, W1, R2, C3 and amplifies network, the echo-signal of carrying out preliminary frequency-selective filtering is carried out further frequency-selecting amplify; Having the characteristics of good high frequency characteristics high-amplification-factor by former device cobasis selective frequency amplifier circuits such as T2, T3, L3, C7, C8, is the main amplifying element of whole high-frequency amplifier circuit.This high-frequency amplifier circuit has very good selecting frequency characteristic, amplifies through three frequency-selectings, at the signal of telecommunication elimination useless noise substantially signal of TP3 output.
Through high frequency frequency-selecting amplifying signal is f
0The high-frequency signal of ± Δ f frequency range is because really the signal that needs is the frequency shift signal Δ f that comprises movable information, so Δ f need be come out from the high-frequency signal demodulation.As shown in figure 12, U1 is an analog switch, f
0The high-frequency signal of ± Δ f frequency range is from the 2 pins input of U1, and B is the reference signal that is used for demodulation with the same homophase frequently that transmits, and C is time gated signal, is used to shield the unwanted echo signal of the non-detection degree of depth.Through the phase demodulation of U1, low frequency signal Δ f is come out by demodulation.The echo-signal frequency range of fetal heart sound is 200Hz~1.5KHz, and the filtered band of the logical amplifying circuit of low-frequency band also should design in this frequency band.
Because the Butterworth designing filter is better than same unit cascaded method for designing, so more near ideal low-pass filter.Butterworth is called the maximally flat wave filter, thus system with Butterworth LPF as signal processing filter.
By the fertile multistage active filter of design now of Bart is a kind of fairly simple wave filter, and in general, the cut-off steepness of characteristic is tending towards ideal characterisitics with the increase of filter order.
Second-order active filter device signal both can also can be imported from end of oppisite phase, but adopt the homophase connection from the in-phase end input of amplifier, made input impedance very big, and output impedance is very little, adopts the homophase connection in the present invention.
Fetal heart sound signal FHR1 through the filtering amplification, still one contains the signal that enriches frequency, if directly this signal is carried out the A/D conversion, directly this sophisticated signal is handled by digital display circuit, then the disposal ability to digital display circuit has higher requirements, manage the operation effect that the MCU of ability can be same for using the lower, need carry out pretreatment to FHR1 with hardware, as shown in figure 13, pre-process circuit is by R1 among the present invention, R2, CV1, D1, D2, U1 constitutes, entire circuit is a precise rectification circuit, complicated fetal heart sound becomes the simple rhythm and pace of moving things signal (as Fig. 9) that the above amplitude of 0V changes with the hear sounds amplitude of variation after rectification, U2 is that sampling hold circuit and digital-to-analogue conversion IC (U3) constitute D/A converting circuit.
As shown in figure 14, be single-chip minimum system, this system's control D/A converting circuit is finished the A/D conversion, and according to auto-correlation algorithm the data that collect is carried out computing, to obtain instantaneous fetal rhythm rate signal.
As shown in figure 15, pressure transducer is exported a small voltage signal at the pressure of receiving that stomach wall transmits, through the output of differential amplifier circuit as shown in figure 15 0-5V pressure signal, and the amplification that W2 can regulating circuit.This signal obtains the palace line of buckling after the A/D of Figure 20 change-over circuit conversion.
Be used for uterine contraction pressure parameter, fetal rhythm rate parameter that the cervical dilatation of calculation processing apparatus output and fetal head position parameter and uterine contraction number pressure digital-to-analog conversion apparatus and the digital-to-analogue conversion of fetal rhythm rate and accountant are exported respectively shown continuously and obtain including cervical dilatation and demonstration printing equipment that fetal head position changes and uterine contraction pressure and fetal rhythm rate change stages of labor curve is also diagnosed according to this and printed.This moment as shown in figure 16, this device mainly is that all data are sent to PC, U12 is the MCU that has the USB2.0 controller, cervical dilatation and fetal head position computing module pass to U12, the calculating of fetal rhythm rate and uterine contraction pressure detecting module to data after handling through the SPI interface data are passed to U12 through serial ports, U12 recombinates the data that receive again, add sign, send to PC through USB interface.
Its major function is exactly that the data that microprocessor transmits are carried out the analysis of Digital Signal Processing, computer, automatically draw out cervix uteri expansion curve, fetal head decline curve, fetal rhythm rate curve, uterine contraction pressure curve, and the meaning of analysis related data, make diagnosis automatically.
Of the present inventionly utilize above-mentioned monitor of stages of labor device to carry out the method for monitor of stages of labor, may further comprise the steps:
(1), with three first sonac, second sonac, the 3rd sonac with transmission-receiving function; Be positioned over puerpera's abdominal part to be monitored with being triangularly arranged and adjust, make first sonac and second sonac be positioned near position puerpera's the anterior superior iliac spine, the 3rd sonac is positioned at puerpera's pubis middle and lower part;
(2), two the 4th sonac, the 5th sonacs with receiving function are positioned over puerpera's cervix uteri mouth both sides, another the 6th sonac with receiving function is positioned over puerpera's fetus head;
(3), pressure transducer and ultrasonic Doppler transducer are positioned over puerpera's abdominal part respectively;
(4), starting ultrasonic signal driving and demodulation process device makes first sonac, second sonac, the 3rd sonac send ultrasound wave, with make the 4th sonac, the 5th pick off and the 6th sonac receive ultrasound wave, calculate distance parameter between each sonac successively according to the actual range between time of the emission of corresponding ultrasonic signal and reception and three the sonacs with transmission-receiving function;
(5), handle and calculate the cervical dilatation and the fetal head position parameter of each time point according to the distance parameter between each measured sonac of step (4);
(6), start uterine contraction pressure detecting and conversion processing unit and the detection of fetal rhythm rate ultrasound-driven and digital-to-analogue conversion and accountant the uterine contraction pressure of each time point and fetal rhythm rate parameter are carried out uterine contraction pressure and the fetal rhythm rate parameter that corresponding digital-to-analogue conversion and computing obtain each time point;
(7), the cervical dilatation of each time point and fetal head position parameter and uterine contraction pressure and fetal rhythm rate parameter being sent to background terminal handles and shows continuously, obtain including the stages of labor curve that cervical dilatation, fetal head position, uterine contraction pressure and fetal rhythm rate change, and carry out diagnostic process and print result according to this stages of labor curve.