JPH04309334A - In vivo object movement detector by ultrasonic doppler method - Google Patents

Abstract

PURPOSE:To obtain the information on in vivo object movements, such as directions, displacement quantities and displacing speeds of the fetal movement, fetal respiration-like movements, etc., which are heretofore not obtainable by an ultrasonic(UT) Doppler method, and to simultaneously obtain not only the information on the ultrasonic probe-fetal movements but also the information on the fetal respiration-like movements and the information on fetal heart beats, etc., with one ultrasonic probe. CONSTITUTION:Burst ultrasonic waves are made incident on the inside of a pregnant woman body 5 from the ultrasonic probe 3 and the received signals are supplied to multipliers 8, 9 by which the signals are subjected to AC-DC detection. The results of the computation are sampled by a timing signal and are digitalized by A/D converters 14, 15. The digital signals are supplied to a microcomputer 16 and are subjected to data processing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic Doppler method detecting device for detecting movement of objects within the body, which can detect movements of objects within the uterus, such as fetal movements, fetal breathing-like movements, and heartbeats.

0002

[Prior Art] In the conventional ultrasound Doppler method for detecting movement of objects within the body such as fetal movements, ultrasound is incident from the abdominal wall of a pregnant woman, and among the reflected waves, a signal is generated by the reflected waves that have undergone Doppler displacement due to the movement of objects within the pregnant woman. were extracted all at once, regardless of the depth from the abdominal wall, and used as a signal for movement of objects within the body, such as fetal movement signals.

0003

[Problem to be solved by the invention] However, in the prior art,
The entire area in which movement of objects within the body in the depth direction can be detected is a single detection area, and for fetal movements, signals exceeding a certain fetal movement detection level were extracted as fetal movement signals, so it is difficult to determine whether the signal exceeds the fetal movement detection level. Small fetal movements that could not be exceeded could not be detected.

[0004] In addition, some motion detection devices using the ultrasonic Doppler method can detect the direction and displacement speed of fast moving parts (such as heart valves) in narrow specific parts of the living body. Fetal movement detection devices using the ultrasonic Doppler method that target the detection area have not been able to detect the direction, amount of displacement, or speed of fetal movement as the movement of objects within the body.

Furthermore, since the amount of displacement of fetal respiration-like movements is small, there is no ultrasonic Doppler method fetal movement detecting device capable of sufficiently detecting them. The present invention
In addition to solving the problems of the conventional technology as described above,
The object of the present invention is to provide a novel ultrasonic Doppler method intra-body object movement detecting device that can obtain displacement velocity, etc., and quantitative in-body object movement information in real time using a single ultrasonic probe.

Furthermore, according to the present invention, not only fetal movement information but also fetal breathing-like movement information, fetal heartbeat information, etc. can be obtained at the same time as internal object movement information, so a single ultrasound probe can simultaneously measure fetal movement. The present invention can provide an ultrasonic Doppler method intra-body object movement detection device that is capable of detecting fetal respiration-like movements and measuring fetal heart rate.

[0007]

[Means for Solving the Problem] The present invention utilizes the ultrasonic Doppler method using burst waves of ultrasound, but in signal processing, electrical signals obtained from reflected ultrasound are orthogonally detected. The direction, displacement amount, displacement speed, etc. of the movement of the object within the body can be obtained from the phase information. At the same time,
By providing a plurality of sample gates and making each sample gate small, each detection region in the depth direction is made small, making it possible to detect even small movements of objects within the body.

[0008] The present invention uses both the orthogonal detection method and multiple sample gate setting in combination to achieve high sensitivity for detecting movement of an object within the body over the entire depth direction of the desired area for detection of movement of the object within the body. Direction and amount of displacement of objects inside the body
The object is to obtain an ultrasonic Doppler method intra-body object movement detection device that can quantitatively obtain displacement velocity and the like. Furthermore, the present invention provides ultrasound Doppler that can detect not only fetal movements but also fetal breathing-like movements and fetal heart rate measurements based on displacement velocity information obtained from the above-mentioned phase information and signal periodicity analysis. A device for detecting movement of objects within a legal body can also be obtained.

[0009]

Embodiment FIG. 1 is an explanatory diagram for explaining the operation of an embodiment according to the present invention, and also serves as a basic configuration diagram of the embodiment. In this example, the desired region for detecting movement of an object within the body was set to a depth range of 2 to 9.5 cm from the abdominal wall, and this target section was divided into five small detection regions of 1.5 cm each.

The operation of this embodiment will be explained with reference to FIG. The 1.1 MHz high-frequency electrical signal generated by the pulse generator 1 is processed by amplification etc. in the transmission amplifier 2, and is converted into a 1.1 MHz burst wave probe drive signal with a repetition period of 3 KHz and a burst length of about 7 μS. and is supplied to the ultrasound probe 3. Ultrasonic waves corresponding to burst waves are generated from the ultrasound probe 3, and the ultrasound waves are incident on the pregnant woman's body 5 through the abdominal wall 4.

[0011] The ultrasonic waves incident on the pregnant woman's body 5 are approximately 15
It propagates inside the body at a speed of 00 m/s and is reflected at various parts of the body. A part of the reflected ultrasonic waves is also reflected to the ultrasonic probe 3, and the ultrasonic energy is converted back into electric energy by the ultrasonic probe 3 and becomes a reception signal, which is sent to the reception amplifier 6.
supplied to The received signal is amplified by a receiving amplifier 6 and then supplied to a first multiplier 8 and a second multiplier 9.

On the other hand, 1.1 generated by the pulse generator 1
The MHz high-frequency electrical signal is also supplied to the first multiplier 8 and, at the same time, to the second multiplier 9 via the 90° phase shifter 7. In the first multiplier 8, the received signal and the first
．． Multiplication with a high frequency electric signal of 1 MHz is performed, and the result of the calculation is supplied to a first low pass filter 10 with a cutoff of 100 KHz, which passes through it to become a low frequency signal, which is supplied to a first sample holder 12.

[0013] In the second multiplier 9, the received signal is multiplied by the 1.1 MHz high frequency electric signal phase-shifted by 90°, and the result of the operation is a cutoff of 100 KHz.
The signal is supplied to a second low-pass filter 11 , passes through this, becomes a low frequency signal, and is supplied to a second sample holder 13 . On the other hand, the pulse generator 1 also generates a timing signal for sampling, and this timing signal is transmitted to the first sample holder 12 and the second sample holder 1.
3. Since the desired region for detecting movement of an object within the body is set as described above, five timing signals are generated for each burst wave generation at 20 μS intervals starting from 26 μS after the end of burst wave generation.

[0014] According to this timing signal, the first sample holder 12 and the second sample holder 13 each sample the result of the multiplication, and hold this as their respective sampling data. The held sampling data is updated one after another by inputting new sampling data according to the next timing signal.

The analog sampling data held in the first sample holder 12 and second sample holder 13 are transferred to a first A/D converter 14 and a second A/D converter 14, respectively.
The data is digitized by the /D converter 15 and supplied to the microcomputer 16. The microcomputer 16 is a 32-bit microcomputer (product manufacturer name and product model name: NEC PC9801RA).
21) was used.

The microcomputer 16 successively takes in ten sampling data for each burst wave generation taken into the first sample holder 12 and the second sample holder 13, and processes the data. The five sets of sampling data for the five detection regions, each set of two, are processed for each burst wave generation and for each detection region, and are sent from the microcomputer 16 as five parallel data for each detection region. It is output sequentially in chronological order.

As this processing process, processing performed by the microcomputer 16 on data in one detection area will be described. For sampling data that comes every time a burst wave is generated with a repetition period of 3 kHz, the microcomputer 16 divides the data of the second A/D converter 15 by the data of the first A/D converter 14, and calculates the quotient arctan. Ru.

Regarding this arctan, ar
As is known as the ctan method, its value represents the distance traveled by the object, and the increase or decrease in its value (changes in polarity at ±∞ are considered continuous) represents the direction in which the object moves. , information about the moving distance and moving direction of the object in this detection area is obtained from this arctan calculation. Information on the moving distance and moving direction for each detection area is further processed by the microcomputer 16 for each detection area over time, and is subjected to integration processing, frequency filter processing, level filter processing, and detection as necessary. Area superimposition and summation processing, fetal heart rate counting processing, etc. are performed, and the microcomputer 16 sequentially outputs five parallel data for each detection region and comprehensive data in chronological order.

The integration process is used to calculate the moving distance of the object. Frequency filter processing is used, for example, to extract only frequency components of 5 Hz or less to effectively extract fetal movement and fetal breathing-like motion components, or to extract only frequency components of 10 Hz or more to effectively extract fetal heartbeat components. Then, perform this process as necessary. Level filter processing is also performed as necessary to facilitate the extraction of target components based on the signal level or to improve the S/N ratio by removing noise. Since it is not particularly necessary to obtain fetal heart rate counting data for each detection area, the superimposition and summation process may be used for the purpose of stabilizing fetal heart rate counting data.

The display device 17 and the recorder 18 output the internal object movement data for each detection area and the fetal heart rate as comprehensive data outputted from the microcomputer 16 in the form of time-series waveforms, letters, numbers, etc. For displaying and recording, various known displays, recorders, etc. can be used. During the above computer calculation process, the moving distance of the object can be calculated with high accuracy by integrating the arctan values. However, as an alternative method, the zero-crossing method of counting the number of zero-crossings of arctan can be easily obtained by using the zero-crossing method, although the accuracy is slightly lowered.

[0021] Also, the first A/D converter 14 (second A/D converter 14)
The frequency of the low-frequency signal obtained as the data envelope of the /D converter 15 is the Doppler frequency itself, so this frequency is the object's moving speed information itself, and this frequency is used for acoustic output. You can also do that. Naturally, the signal processing process of the embodiment described above is as follows.
Appropriate changes and additions can be made. For example, the receiving amplifier 6 may be configured to supply a signal for only a necessary period to each multiplier, or may be provided with an AGC function. It goes without saying that the number of samplings and the timing signal generation time can be changed, and the sampling intervals do not have to be evenly spaced, and sampling may be performed intermittently.

[0022] Furthermore, since these information processes can be performed online and results can be obtained in real time, they can be used for fetal monitoring as new fetal information that could not be obtained using conventional methods. FIG. 2 is a diagram for simply schematically explaining the flow of signal processing according to this embodiment, and both horizontal axes are time axes.

FIG. 2A shows a 1.1 MHz burst wave with a repetition period of 3 KHz and a burst length of approximately 7 μS, which is supplied to the ultrasonic probe 3. (b-1) and (b-2) are the received signals from the ultrasound probe 3 and 9.
Multiplying the 0° phase-shifted received signal and the 1.1 MHz high-frequency electrical signal by a first multiplier and a second multiplier,
It shows two low frequency signals obtained through a low pass filter. These two low frequency signals are obtained by the receiving amplifier 6 only during a limited signal supply period as shown in the figure, and are received at times of ■■■■■ at intervals of 20 μS.
■Sampled as channel data.

(c-1) and (c-2) compress the time axis (for example, 10
1/0) and the Doppler waveform shown by its envelope. FIG. 3 is an example of a record obtained by this example,
In-body object movement information is shown for five detection areas with different depths from the abdominal wall. It clearly shows the difference in the movement of objects inside the body due to the difference in depth.
A waveform that is presumed to be a breathing-like movement of the fetus has been obtained.

Furthermore, FIG. 4 shows a waveform in which components of 10 Hz or more are extracted from the phase information, and the heartbeat component is clearly shown.

[0026]

[Application of the Invention] As an application, the present invention provides an ultrasonic Doppler intra-body object movement detection device capable of measuring labor pain by combining it with a labor pain information collection processing section consisting of a labor pain measurement transducer, a labor pain measurement circuit, etc. ,
It is also possible to provide a childbirth monitoring device with improved performance in measuring movement of objects within the body such as fetal movements.

[0027] The present invention also includes an ultrasound Doppler method intra-body object movement detection device that includes a fetal heart rate information collection processing unit that obtains fetal information such as fetal heart rate based on fetal heart sounds and fetal electrocardiograms, and has extended fetal heart rate information input means. For example, it is also possible to provide a childbirth monitoring device with improved performance in measuring movement of objects within the body such as fetal movements. Furthermore, in order to obtain fetal information about multiple pregnancies, it is easy to create an ultrasound Doppler intra-body object movement detection device that is equipped with multiple ultrasound probes and can obtain fetal information about multiple fetuses by making some changes. Furthermore, by combining with the above-mentioned labor pain information collection processing section and fetal heartbeat information collection processing section, an excellent delivery monitoring device for multiple births can be obtained.

[0028]

[Effects of the Invention] According to the present invention, the sensitivity for detecting movement of an object within the body is high over the entire depth direction of the desired region for detection of movement of an object within the body, and even small fetal movements can be detected, and the direction and amount of displacement of the object within the body can be detected. - It is possible to provide an ultrasonic Doppler intra-body object movement detection device that can quantitatively obtain displacement velocity, etc. in real time.

[0029] Furthermore, we have developed an ultrasonic Doppler intra-body object movement detection device that can simultaneously obtain not only fetal movement information but also fetal breathing-like movement detection and fetal heart rate measurement in real time using a single ultrasonic probe. can be provided. Furthermore, in combination with a labor pain information collection processing unit and a fetal heart rate information collection processing unit equipped with other fetal heart rate information input means, quantitative direction and displacement of fetal movements can be obtained as new fetal monitoring information not previously available. - It is also possible to provide a delivery monitoring device that has a function of providing information such as displacement speed and fetal breathing-like movement information.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the operation of an embodiment according to the present invention, which also serves as a basic configuration diagram.

FIG. 2 is a diagram for explaining the flow of signal processing according to the present embodiment, where the horizontal axis is the time axis, and (a) shows the burst wave supplied to the ultrasound probe 3; b-1) and (b
-2) are two low-frequency signals of the low-pass filter output, (
c-1) and (c-2) are waveforms showing the envelope of a set of sampling data for one channel by compressing the time axis.

FIG. 3 is a record showing a waveform estimated to be a breathing-like movement of the fetus obtained by this example.

FIG. 4 is a waveform showing a fetal heartbeat component obtained by this example.

[Explanation of symbols]

1 Pulse generator 2 Transmission amplifier 3 Ultrasonic probe 4 Abdominal wall 5 Inside the pregnant woman's body 6 Receiving amplifier 7 90° phase shifter 8 First multiplier 9 Second multiplier 10 First low-pass filter 11 Second low-pass filter 12 First sample holder 13 Second sample holder 14 First A/D converter 15 Second A/D converter 16 Microcomputer 17 Display 18 Recorder

Claims (12)

[Claims] 1. A signal generating unit that generates a high-frequency electric signal of a constant frequency, an electric pulse of a constant repetition period, and a timing signal corresponding to the electric pulse, and a burst wave of ultrasonic waves of the constant frequency that enters the body from the abdominal wall of a pregnant woman. an ultrasonic probe that injects the ultrasonic waves at the constant repetition period and receives reflected ultrasonic waves from the body and converts them into received electrical signals;
a phase information output unit that outputs a set of phase information obtained for each burst wave each time the burst wave is generated; a direction, displacement amount, and displacement speed of an object within the body that processes the phase information;
An information processing unit that obtains fetal information such as fetal heart rate and fetal heart rate fluctuation information, and processes the fetal information as necessary and outputs it by displaying/recording temporal change waveforms, letters, numbers, etc., or by sound output, etc. An ultrasonic Doppler intra-body object movement detection device equipped with a display/recording section. 2. The ultrasound Doppler intra-body object movement detection device according to claim 1, further comprising a labor pain information collection processing section, wherein said display/recording section also outputs the labor pain information from said labor information collection processing section. 3. A fetal heartbeat information collection processing section for obtaining fetal heartbeat information from information such as ultrasound Doppler, fetal electrocardiogram, fetal heart sounds, etc. other than information from the ultrasound probe; 3. The ultrasonic Doppler intra-body object movement detection apparatus according to claim 2, wherein the recording section also outputs the fetal heartbeat information from the fetal heartbeat information collection processing section. 4. The phase information output unit includes a 90° phase shifter, two multipliers, two low-pass filters, two sample holders, and two A/D converters, and performs orthogonal detection of the received electrical signal. 2. The ultrasound Doppler in-body object according to claim 1, wherein a set of phase information each consisting of a plurality of sampling data obtained for both phases by time-division in time series for each burst wave is output every time the burst wave is generated. Movement detection device. 5. The ultrasound Doppler intra-body object movement detection device according to claim 4, further comprising a labor pain information collection processing section, and wherein said display/recording section also outputs the labor pain information from said labor information collection processing section. 6. A fetal heartbeat information collection processing section for obtaining fetal heartbeat information from information such as ultrasound Doppler, fetal electrocardiogram, fetal heart sounds, etc. other than information from the ultrasound probe; 6. The ultrasonic Doppler intrabody object movement detection device according to claim 5, wherein the recording section also outputs the fetal heartbeat information from the fetal heartbeat information collection processing section. 7. A signal generating unit that generates a high-frequency electric signal of a constant frequency, an electric pulse train of a constant repetition period, and a timing signal corresponding to the electric pulse train; a plurality of ultrasonic probes that are incident at the constant repetition period and receive reflected ultrasonic waves from the body and convert them into received electrical signals; a phase information output unit that outputs a set of phase information obtained from each burst wave every time the burst wave occurs; An information processing unit that obtains fetal information of multiple fetuses such as variable information, and a display/record that processes the fetal information as necessary and outputs it by displaying/recording changes over time, letters, numbers, etc., or by sound output, etc. An ultrasonic Doppler intra-body object movement detection device comprising: 8. The ultrasound Doppler intra-body object movement detection device according to claim 7, further comprising a labor pain information collection processing section, wherein said display/recording section also outputs the labor pain information from said labor pain information collection processing section. 9. A fetal heartbeat information collection processing unit for obtaining fetal heartbeat information from information such as ultrasound Doppler, fetal electrocardiogram, fetal heart sounds, etc. other than information from the ultrasound probe; 9. The ultrasonic Doppler intra-body object movement detection apparatus according to claim 8, wherein the recording section also outputs the fetal heartbeat information from the fetal heartbeat information collection processing section. 10. The phase information output section includes a 90° phase shifter, two multipliers, two low-pass filters, two sample holders, and two A/D converters, and performs orthogonal detection of the received electrical signal. 8. The ultrasound Doppler in-body object according to claim 7, wherein a set of phase information each consisting of a plurality of sampling data obtained for both phases by time-division in time series for each burst wave is output every time the burst wave is generated. Movement detection device. 11. The ultrasonic Doppler intra-body object movement detection device according to claim 10, further comprising a labor pain information collection processing section, and wherein said display/recording section also outputs the labor pain information from said labor information collection processing section. 12. A fetal heartbeat information collection processing unit for obtaining fetal heartbeat information from information such as ultrasound Doppler, fetal electrocardiogram, fetal heart sounds, etc. other than the information from the ultrasound probe,
12. The ultrasonic Doppler intra-body object movement detection device according to claim 11, wherein said display/recording section also outputs said fetal heartbeat information from said fetal heartbeat information collection processing section.