JP2002131427A - Ultrasonic searching method and device, and ultrasonic analyzing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ultrasonic searching device that can more quickly measure and can obtain a very fine image. SOLUTION: A signal generating device 110 generates transmitting signals by modulating a carrier wave with prescribed frequency by pseudo random number signals that are M-group signals MS(1) to MS(n) here with no mutual correlation with the carrier wave. Ultrasonic transmitters 120(1) to 120(n) convert these signals to ultrasonic waves to irradiate all together to a measured object. Ultrasonic receivers 130(1) to 130(m) receive the reflection of this ultrasonic wave by the measured object. Signal separating devices 140(1) to 140(m) separate to the received signals of the ultrasonic receivers 130(1) to 130(m) with respective to each derivation by mutually correlating the M-group signals used for the modulation with the received signals. A data processor 150 obtains the position and the three-dimensional shape of the measured object by executing spatial statistic processing (aperture synthesis) on these separated signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic detection method and apparatus for detecting an object to be measured using ultrasonic waves, and an ultrasonic analysis apparatus.

[0002]

2. Description of the Related Art A technique has been developed for irradiating an object to be measured with ultrasonic waves and subjecting the reflected wave to spatial statistical processing (for example, aperture synthesis) to search for the position and shape of the object to be measured. .

In this technique, the more the number of transmission points and reception points of ultrasonic waves, the more detailed images (higher resolution images) can be obtained. In addition, the measurement range can be expanded. For this reason, when a detailed image is required, the receiving points are increased by arranging a large number of receiving elements. On the other hand, the transmission point has been dealt with by performing measurement while moving the transmission element, that is, by repeatedly performing measurement while shifting the position of the transmission element.

[0004]

However, in the above-mentioned prior art, the time required to complete the measurement was very long because the measurement was performed while moving the transmitting element. Therefore, there has been a demand for a technique capable of performing measurement in a shorter time.

To reduce the measurement time, it is conceivable to increase the moving speed. However, there is a limit to the speed at which the transmitting element is moved due to various factors such as the influence on the measurement.

Accordingly, the present invention has been made in view of the above, and an object of the present invention is to provide an ultrasonic exploration method and apparatus, and an ultrasonic analyzer which can complete a measurement in a shorter time. I do.

[0007]

In order to achieve the above object, an ultrasonic probe according to claim 1 comprises: a transmitting means for generating a signal of a predetermined frequency (hereinafter referred to as a "carrier signal"); A noise signal generating means for generating a signal; a modulating means for generating a transmission signal by modulating the carrier signal using the pseudo-random number signal; and a transmission unit, and converting the transmission signal from the transmission unit to an ultrasonic wave. Transmitting means for transmitting toward the measurement object and receiving the ultrasonic waves transmitted by the transmission means and reflected by the measurement object, and converting the received ultrasonic waves into an electric signal (hereinafter, referred to as a “reception signal”) Receiving means for converting and outputting, a separating means for separating a signal included in the received signal by correlating the received signal with the pseudo random number signal, and a signal separated by the separating means. Te By performing the aperture synthesis, and is characterized in that it comprises a data processing means for determining the position and / or shape of the measurement object.

According to the first aspect of the present invention, the transmitting means generates a carrier signal. The noise signal generating means,
Generate a pseudorandom signal. The modulating means generates a transmission signal by modulating the carrier signal using the pseudo random number signal. The transmitting unit converts the transmission signal from the transmission unit into an ultrasonic wave and transmits the ultrasonic wave to the measurement target. The receiving means receives the ultrasonic wave reflected by the measurement object, converts the received ultrasonic wave into an electric signal (received signal), and outputs the electric signal. The separating unit separates a signal included in the received signal by correlating the received signal with the pseudo random number signal. The data processing unit obtains the position and / or shape of the measurement object by performing aperture synthesis on the signal separated by the separation unit.

According to a second aspect of the present invention, there is provided an ultrasonic probe, comprising: a transmitting means for generating a signal of a predetermined frequency (hereinafter referred to as a "carrier signal"); And, by modulating the carrier signal using each of the pseudo-random number signal, comprising a modulation means for generating a plurality of types of transmission signals, a plurality of transmission units arranged at different positions from each other, the transmission unit Transmitting means for converting a mutually different transmission signal into an ultrasonic wave and transmitting it toward the measurement target, and a plurality of receiving units arranged at different positions from each other, transmitted by the transmission means and transmitted by the measurement target Receiving means for receiving the reflected ultrasonic wave by each of the receiving units, converting the received ultrasonic wave into an electric signal (hereinafter, referred to as a “received signal”) and outputting the electric signal; A separating unit that separates a signal included in the received signal for each of the pseudo random number signals, and performs aperture synthesis on the signals separated by the separating unit by correlating the received signal with each of the pseudo random number signals. And a data processing means for obtaining the position and / or shape of the object to be measured.

According to the second aspect of the present invention, the transmitting means generates a carrier signal. The noise signal generating means generates a plurality of types of pseudo random number signals having no correlation with each other. The modulating means generates a plurality of types of transmission signals by modulating the carrier signal using each of the pseudo-random number signals. A transmission unit converts transmission signals different from each other from each of the transmission units into ultrasonic waves and transmits the ultrasonic waves toward the measurement target. Receiving means receives the ultrasonic wave reflected by the measurement object by each of the receiving units, converts the received ultrasonic wave into an electric signal (received signal), and outputs the electric signal. Separating means separates a signal included in the received signal into each pseudo-random number signal by correlating the received signal with each of the pseudo-random number signals. The data processing unit obtains the position and / or shape of the measurement object by performing aperture synthesis on the signal separated by the separation unit.

According to a third aspect of the present invention, in the ultrasonic exploration apparatus according to the second aspect, the transmitting means transmits ultrasonic waves simultaneously from a plurality of transmitting units. It is.

According to the third aspect of the present invention, the transmitting means transmits the ultrasonic waves from the plurality of transmitting units all at once.

According to a fourth aspect of the present invention, in the ultrasonic probe according to any one of the first to third aspects, the modulating means modulates a phase and an amplitude of the carrier signal. It is characterized by the following.

According to the present invention, the modulating means modulates the phase and the amplitude of the carrier signal.

According to a fifth aspect of the present invention, in the ultrasonic probe according to any one of the first to fourth aspects, the pseudo random number signal is an M-sequence signal. .

According to the fifth aspect of the present invention, an M-sequence signal is used as the pseudo random number signal.

According to a sixth aspect of the present invention, in the ultrasonic probe according to any one of the second to fourth aspects, a plurality of the transmitting units are arranged around the receiving unit. It is characterized by the following.

According to the present invention, a plurality of transmitting units are arranged around the receiving unit.

According to a seventh aspect of the present invention, an ultrasonic analyzer converts a signal obtained by modulating a carrier with a pseudo-random number signal into an ultrasonic wave, irradiates the ultrasonic wave to a measurement object, and reflects the ultrasonic wave on the object. In an ultrasonic analyzer used for an ultrasonic probe that searches for an object to be measured by analyzing a received signal obtained by receiving the received signal, the received signal and the pseudo random number signal used for the modulation are input. The correlation between the received signal and the pseudo random number signal,
Separating means for separating a signal included in the received signal; and data processing means for performing aperture synthesis on the signal separated by the separating means to obtain the position and / or shape of the measurement object. It is characterized by having.

According to the present invention, the separating means separates the signal included in the received signal by correlating the received signal with the pseudo random number signal. The data processing unit obtains the position and / or shape of the measurement target by performing aperture synthesis on the signal separated by the separation unit.

According to an eighth aspect of the present invention, in the ultrasonic analysis apparatus according to the seventh aspect, the separation means is configured to be capable of inputting a plurality of pseudo random number signals, and the separation is performed for each pseudo random number signal. Is to be performed.

According to the eighth aspect of the present invention, the separating means performs the separation for each of the inputted pseudo random number signals.

According to a ninth aspect of the present invention, in the ultrasonic analysis apparatus according to the eighth aspect, the pseudo random number signal is an M-sequence signal.

According to the present invention, an M-sequence signal is used as the pseudo random number signal.

According to a tenth aspect of the present invention, an ultrasonic search method irradiates an ultrasonic wave toward an object to be measured, and analyzes the received signal obtained by receiving the reflection to search for the object to be measured. In the ultrasonic detection method, a transmission signal is generated by modulating a signal of a predetermined frequency (hereinafter, referred to as a “carrier signal”) with a pseudo-random number signal, and the transmission signal is converted into an ultrasonic wave and transmitted to an object to be measured. While receiving the ultrasonic wave reflected by the measurement object, separating the signal included in the received signal by correlating the received signal with the pseudo random number signal, and regarding the separated signal The position and / or shape of the object to be measured is obtained by performing aperture synthesis.

According to the tenth aspect of the present invention, the measurement object is searched for by irradiating the ultrasonic wave toward the measurement object and analyzing a reception signal obtained by receiving the reflection. In this method, a transmission signal is generated by modulating a carrier signal with a pseudo random number signal. Then, the transmission signal is converted into an ultrasonic wave and transmitted toward the object to be measured. The ultrasonic wave reflected by the object to be measured is received, and a signal included in the received signal is separated by correlating the received signal with a pseudo random number signal. Then, by performing aperture synthesis on the separated signals, the position and / or shape of the measurement target is obtained.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

This embodiment is characterized mainly in that measurement from a large number of transmission points is performed simultaneously to shorten the measurement time. More specifically,
The measurement is performed by simultaneously irradiating the ultrasonic waves by the plural ultrasonic transmitters 120. In order to realize this, modulation processing is performed by using a pseudo random number signal when generating an ultrasonic signal, and cross-correlation processing with the pseudo random number signal is performed when separating a received signal. The details will be described below.

The ultrasonic probe 100 according to the present embodiment
Signal generator 110 and ultrasonic transmitters 120 (1)-
(N), the ultrasonic receivers 130 (1) to (m), the signal separators 140 (1) to (m), and the data processor 15
0 and a display device 160. In addition,
The ultrasonic transmitters 120 (1) to 120 (n) may be simply referred to as the ultrasonic transmitter 120 unless it is necessary to distinguish each of them. Ultrasonic receiver 130 (1)
To (m) and the signal separation devices 140 (1) to (m), similarly,
It may be written. The same applies to the description in the drawings.

The signal generator 110 generates an electric signal which is a source of ultrasonic waves. As shown in FIG. 2, a signal generator 110 according to this embodiment has a transmitter 111
, A pseudo-random signal generator 112, a modulation circuit 113
(1) to (n). The modulation circuits 113 (1) to 113 (n) may be simply referred to as the modulation circuit 113 unless it is necessary to distinguish each of them. The same applies to the description in the drawings.

The transmitter 111 is for generating a carrier wave of a predetermined frequency for exploring the inside of the object P to be measured. In this embodiment, the frequency is 5 to 10 MHz.
Signal is generated. The transmitter 111 outputs the generated carrier signal to the modulation circuit 113.

In this embodiment, a plurality of ultrasonic transmitters 120 are provided, and all of them are simultaneously (or
Due to the transmission of the ultrasonic waves (at substantially the same time), if the carrier waves are output from the ultrasonic transmitter 120 as they are, they interfere with each other and cannot be separated. Therefore, in order to enable separation of each carrier, the carrier is modulated by an M-sequence signal described later and then output from the ultrasonic transmitter 120.

The pseudo-random number signal generator 112
Pseudo random number signal MS for modulating the carrier wave generated by
(1) to (n) are generated. The pseudo-random number signals MS (1) to (n) may be simply referred to as pseudo-random number signals MS unless it is necessary to distinguish them. The same applies to the description in the drawings. The pseudo random number signals MS (1) to (n) have no correlation with each other and have sufficiently long periods.

The pseudo random number signal generator 112 converts the generated pseudo random number signal MS into a modulation circuit 113 and a correlator 1.
42. In this case, different pseudo random number signals MS are output to each modulation circuit 113 and correlator 142. For example, a pseudo random number signal MS (1)
Are output to the modulation circuit 113 (1) and the correlator 142 (1). Further, the pseudo random number signal MS (2) is output to the modulation circuit 113 (2) and the correlator 142 (2).

In this embodiment, the pseudo random number signal M
As S, an M-sequence signal having excellent correlation characteristics is adopted. The M-sequence (maximal-length sequence) signal is generated by feeding back the logical combination of the state of each stage to the input of the shift register in a shift register of a certain length in the pseudo random sequence (PN) signal. It refers to a sequence whose code cycle is the longest among the code sequences. Assuming that N is the number of stages of the shift register, the unit length (L) is defined by the following equation (1).

L = 2 ^N -1 (1) As the unit length (L) is longer, the S / N ratio is improved, and better results are obtained. In this embodiment, N is 10
The above M-sequence signal is used. The actual length of the M-sequence signal is obtained by multiplying the unit length L by the sampling clock.

The modulation circuit 113 includes the pseudo random number signal generator 1
The carrier (signal) generated by the transmitter 111 is modulated by the pseudo random number signal MS input from the transmitter 12. The actual modulation circuit 113 includes a multiplier. The modulation circuits 113 (1) to 113 (n) are associated with the ultrasonic transmitters 120 (1) to 120 (n) in a one-to-one relationship. Then, the modulation circuit 113 outputs the operation result (modulation result) to the corresponding ultrasonic transmitter 120.

The ultrasonic transmitter 120 is connected to the signal generator 11
The ultrasonic wave is generated based on a signal input from 0. The ultrasonic transmitter 120 is fixedly arranged at a predetermined position in the liquid medium by a fixing mechanism (not shown) (see FIG. 3). Naturally, the positional relationship between the ultrasonic transmitter 120 and the measuring object P is known in advance.

The ultrasonic receiver 130 is for receiving ultrasonic waves. The ultrasonic receiver 130 is configured to output the received ultrasonic waves to the signal separating device 140. The ultrasonic receiver 130 is fixedly arranged at a predetermined position in the liquid medium by a fixing mechanism (not shown) (see FIG. 3). Naturally, the positional relationship between the ultrasonic receiver 130 and the measurement target P is known in advance. Naturally, the positional relationship with the ultrasonic transmitter 120 is also known.

In this embodiment, the plurality of ultrasonic transmitters 120 are connected to the ultrasonic
Around each other as far as possible from each other.
Specifically, as shown in FIG. 3, in this embodiment,
The ultrasonic transmitter 120 and the ultrasonic receiver 130 are arranged in a matrix. In two orthogonal directions (four directions) around the ultrasonic receiver 130, the ultrasonic transmitter 12
0 are respectively arranged. The ultrasonic transmitter 12
When the zeros and the ultrasonic receivers 130 are arranged in series in a row, they are alternately arranged (that is, the ultrasonic transmitters 120 are arranged on both sides of the ultrasonic receiver 130).

The signal separating device 140 includes the ultrasonic receiver 13
This is for separating the ultrasonic wave received by 0 for each origin. Signal separation device 1 of this embodiment
As shown in FIG. 4, 40 includes a signal distributor 141 and correlators 142 (1) to (n). The correlators 142 (1) to (n) may be simply referred to as the correlators 142 when it is not necessary to distinguish them. The same applies to the description in the drawings.

The signal distributor 141 includes the ultrasonic receiver 130
Are received by the correlators 142 (1)-
(N).

The correlator 142 separates the signal received by the ultrasonic receiver 130 for each ultrasonic transmitter 120 from which the signal is derived. This separation is
This is performed by obtaining a cross-correlation between the received signal and the pseudo random number signal MS generated by the pseudo random number signal generator 112. As described above, the pseudo random number signal M input to the correlators 142 (1) to (n)
S (1) to S (n) are different from each other and have no correlation.

The data processing device 150 (FIG. 1) performs spatial statistical processing on the signal separated by the signal separating device 140, in this case, aperture synthesis (Aperture Synthesis) to obtain the three-dimensional shape of the object P to be measured. Is what you want. The data processing device 150 is specifically configured by a DSP (Digital Signal Processor), a microprocessor, a memory, and the like. Various data required for measurement and data processing (for example, information indicating the positions of the ultrasonic transmitter 120 and the ultrasonic receiver 130) and programs are stored in a memory in advance.

The display device 160 (FIG. 1) is for displaying the result obtained by the data processing device 150, for example, the position of the measuring object P, a three-dimensional image, and the like.

The “carrier signal” in the claims corresponds to a signal generated and output by the transmitter 111 in this embodiment. “Transmitting means” corresponds to the transmitter 111. “Noise signal generating means” corresponds to the pseudo random number signal generator 112. "Modulation means"
It corresponds to the modulation circuit 113. The “transmission signal” is a signal modulated by a pseudo random number signal, that is, the modulation circuit 1
13 corresponds to a signal output to the ultrasonic transmitter 120. The “transmitter” corresponds to the ultrasonic transmitter 120.
The “transmitting means” includes the ultrasonic transmitter 120 and all mechanisms for operating and fixing the ultrasonic transmitter 120. The “receiving unit” corresponds to the ultrasonic receiver 130. The “receiving means” includes the ultrasonic receiver 130 and all mechanisms for operating and fixing the ultrasonic receiver 130. The “received signal” corresponds to a signal output from the ultrasonic receiver 130 to the signal separation device 140. The “separating unit” is realized by the signal separating device 140. “Data processing means” corresponds to the data processing device 150. However, the above components operate in close cooperation with each other, and the correspondence described here is not strict.

Next, the operation will be described. First, the transmission operation of the ultrasonic wave will be described with reference to FIGS. Prior to the start of the measurement, the measuring object P is submerged in a liquid medium such as water. Ultrasonic transmitter 120 and ultrasonic receiver 1
30 is also located in this liquid medium.

When the measurement is started, in the signal generator 110, the transmitter 111 generates a carrier signal, and the pseudo random number signal generator 112 generates a pseudo random number signal (specifically, an M-sequence signal) MS. As shown in FIG. 5, the modulation circuit 113 modulates the phase and amplitude of the carrier signal with the pseudo random number signal MS.

The modulation circuit 113 outputs the modulated signal to the ultrasonic transmitter 120. Ultrasonic transmitter 120
Converts this signal (electric signal) into an ultrasonic wave and then emits it toward the measurement object P. The ultrasonic waves are respectively reflected by the measurement object P, and the reflected waves are received by the ultrasonic receiver 130.

Next, the operation of analyzing the reception of ultrasonic waves will be described with reference to FIGS. 1, 4 and 6. FIG. Ultrasonic receiver 13
0 indicates the received ultrasonic wave as an electric signal (hereinafter, "received signal")
After that, the signal is output to the signal separation device 140. The signal distributor 141 distributes the received signal to each of the correlators 142 for input.

The correlator 142 includes the pseudo random number signal generator 11
2, a pseudo random number signal (here, an M-sequence signal) MS is input. The correlator 142 correlates the pseudo random number signal MS with the received signal as shown in FIG.
The reflected waves from the corresponding ultrasonic transmitter 120 are separated.
In this case, the pseudo random number signals MS input to each of the correlators 142 (1) to (n) have no correlation with each other. Therefore, each correlator 142 can reliably separate only a signal corresponding to a signal modulated by the same pseudo random number signal MS that is input to itself. For example, the correlator 142 (1) includes the ultrasonic transmitter 120 (1)
Only those originating from. Further, the correlator 14
2 (2) separates only those originating from the ultrasonic transmitter 120 (2).

As described above, the correlator 142 separates the signal (received signal) received by the ultrasonic receiver 130 for each origin, and outputs the separated signal to the data processing device 150. In this embodiment, an M-sequence signal having excellent correlation characteristics is used for signal processing in modulation and separation (demodulation), and the length is sufficiently long, so that separation is performed more reliably. In the case of a long pseudo-random number signal, the pseudo-random number signals may partially approximate each other. And a peak resulting from such partial approximation may occur. However, peaks caused by such factors can be predicted in advance, and can be removed by signal processing.

The data processing device 150 includes the correlator 142
By performing aperture synthesis on the signal input from the CPU, data indicating the three-dimensional shape or the like of the measurement target P is obtained. Hereinafter, the principle of the aperture synthesis will be briefly described with reference to FIG.

The timing of the peak included in the signal separated by the correlator 142 is such that the ultrasonic wave modulated by the pseudo random number signal MS used for the separation by the correlator 142 is transmitted to the ultrasonic receiver 130. Indicates the time of arrival. Therefore, the elapsed time from the time when the ultrasonic wave was transmitted to its peak (t ₁₁ , t ₁₂ , t ₂₁ ,
t ₂₂ ) corresponds to the length of the path [ultrasonic transmitter 120 測定 measurement object P 超 ultrasonic receiver 130] that has been followed. Incidentally, t ₁₁ is the time elapsed for the ultrasonic wave following the routes of transmission points 1-- measuring object P-- reception point 1 in FIG. t ₁₂ is the transmission point 1—the object P to be measured
--- It is the elapsed time of the ultrasonic wave following the route of the receiving point 2. t ₂₁ is the time elapsed for the ultrasonic wave following the routes of transmission points 2-- measured object P-- receiving point 1. t _22, the transmission point 2 - the measuring object P-- receiving point 2
It is the elapsed time of the ultrasonic wave following the path.
ν is a proportional constant corresponding to the velocity of the ultrasonic wave in the liquid medium.

Therefore, a set of positions satisfying the path length traced by the ultrasonic wave transmitted from a certain transmission point (that is, an ellipsoid having the transmission point and the reception point as focal points, and an arbitrary position on the surface and both positions) An ellipsoidal surface whose sum of the distance to the focal point corresponds to the elapsed time) is obtained based on measurement data at various reception points. The intersection of each ellipsoidal surface thus obtained is the position of the measuring object P.

Further, by performing the same arithmetic processing on the measurement results at a larger number of transmission points and reception points, data indicating the three-dimensional shape and the like of the measuring object P (for example, coordinate data at various points on the surface) can be obtained. Obtainable.

There are various methods for specific calculations, but any method may be used in this embodiment.
Since the aperture synthesis itself is a well-known technique, further detailed description will be omitted.

After obtaining the data indicating the three-dimensional shape and the like of the measuring object P by the above-described aperture synthesis, the data processing device 150 creates image data depicting the measuring object P based on this data, The display device 160
Output to The display device 160 displays this image data, that is, a three-dimensional image of the measuring object P.

As described above, according to the ultrasonic probe of this embodiment, the following effects can be obtained.

The ultrasonic signal generally has a large attenuation, but in this embodiment, the carrier is modulated by using a pseudo-random number signal, so that it is hardly affected by the attenuation. Further, the separation of the received signal is performed by cross-correlating the pseudo-random number signal used for this modulation with the received signal, so that these can be reliably separated. Therefore, the measurement sensitivity is high. In this embodiment, since both the phase and the amplitude are modulated, such an effect is higher. Further, such an effect is further enhanced because an M-sequence signal having excellent correlation characteristics is employed as the pseudo random number signal. Also, the M-sequence signal has an advantage that a circuit for generation is simple.

In this embodiment, since a plurality of ultrasonic transmitters 120 are used, and the ultrasonic waves are transmitted from them at once, the time required for the measurement can be reduced. When the ultrasonic waves are transmitted at the same time, the ultrasonic waves transmitted by the respective ultrasonic transmitters 120 interfere with each other. However, as described above, in this embodiment, since a pseudo-random number signal is used for modulating a carrier wave and separating a received signal,
Even if such interference occurs, the received signal can be reliably separated. Therefore, there is no problem at all.

Further, since the plurality of ultrasonic transmitters 120 are arranged around the ultrasonic receiver 130, the receivable range of the ultrasonic receiver 130 can be fully utilized. That is, the measurable range is wide.

In the above embodiment, the ultrasonic transmitter 1
There is no need for a mechanism for moving 20 or the like. Therefore, it is advantageous in terms of maintenance and the like. Further, since the ultrasonic transmitter 120 can be completely fixed and its position can be defined more precisely, higher measurement accuracy can be realized.

Since the flow of the liquid medium affects the time from the transmission of the ultrasonic wave to the reception point, the measurement is performed in a state where the liquid medium is completely stationary in order to perform a highly accurate measurement. There is a need. In the above-described embodiment, the ultrasonic transmitter 1 is immersed in the liquid medium in which the measurement object P is immersed.
Since the liquid medium 20 does not need to be moved, the measurement can be performed with the liquid medium completely stopped. Therefore, more accurate measurement can be performed quickly. In the related art in which the measurement is performed while moving the ultrasonic transmitter 120, if the measurement is performed after completely stopping the liquid medium for each transmission point, similarly high-precision measurement is possible. . However, the time required for the liquid medium to come to rest is very long, so that there are many difficulties in practice.

In the above-described embodiment, since it is assumed that ultrasonic waves are output from all the ultrasonic transmitters 120 at the same time, only pseudo random number signals MS having no correlation with each other are used. When the transmission timing of the ultrasonic transmitter 120 is shifted, the pseudo random number signals MS (1) to
Not all of (n) need be necessarily uncorrelated. For example, the ultrasonic transmitter 120 is divided into a first group (the ultrasonic transmitters 120 (1) to (n / 2)) and a second group.
Group (ultrasonic transmitter 120 (n / 2 + 1)-
(N)) and when the transmission is performed with the timing shifted sufficiently for each group, the ultrasonic transmitter 120 (1) and the ultrasonic transmitter 120 (n / 2 + 1) have a correlation. A pseudo random number signal (or the same pseudo random number signal) may be used.

In the above-described embodiment, the measurement result, that is, the data indicating the three-dimensional shape of the measurement object P is displayed after being imaged. However, the output form of the measurement result is not limited to this. Absent. Data indicating the surface shape or the like of the measurement target P (for example, coordinate data of various points on the surface) may be displayed on the display device 160 as characters.

[0067]

As described above, the ultrasonic detecting method and apparatus and the ultrasonic analyzing apparatus according to the present invention enable quick and highly accurate measurement. The details are as follows.

According to the first aspect of the present invention, since the modulation and the separation are performed using the pseudo random number signal, the separation of the signal is assured. Therefore, the measurement sensitivity is high.

According to the second aspect of the present invention, since the modulation and the separation are performed using the pseudo random number signal, the separation of the signal is assured. Therefore, the measurement sensitivity is high. Further, since a plurality of transmission units and reception units are provided, more accurate measurement is possible. In this case, since it is not necessary to move the transmission unit or the like, the measurement can be performed while the stationary state of the medium in which the measurement object is immersed is maintained. Therefore, the measurement is faster and more accurate.

According to the third aspect of the present invention, since the ultrasonic waves are transmitted simultaneously from the plurality of transmission units, the measurement time is short. In this case, it is conceivable that the ultrasonic waves transmitted from each transmitting unit interfere with each other, but since the pseudo random number signal is used for the modulation and separation of the signals, each of the signals caused by each ultrasonic wave is surely separated. be able to. Therefore, a decrease in measurement accuracy (or measurement sensitivity) does not occur.

According to the fourth aspect of the present invention, by performing modulation using both the phase and the amplitude, the separation can be made more reliable. Therefore, higher measurement sensitivity can be obtained.

According to the fifth aspect of the present invention, since the M-sequence signal has excellent correlation characteristics, the signal can be more reliably separated.

According to the sixth aspect of the present invention, it is possible to make the most of the range in which the transmitting unit can transmit ultrasonic waves and the range in which the receiving unit can receive ultrasonic waves. Therefore,
The measurable range is wide.

According to the seventh aspect of the present invention, since the separation is performed using the pseudo random number signal used for the modulation, the separation can be reliably performed (the S / N ratio is high). Therefore, in the ultrasonic probe using this, the measurement sensitivity is high.

According to the eighth aspect of the present invention, it is possible to separate signals for each pseudo random number signal used for modulation. If an ultrasonic probe is configured using such an ultrasonic analyzer, it is possible to perform measurement by irradiating ultrasonic waves modulated by mutually different pseudo-random number signals from a plurality of transmission units. Therefore, more accurate and quick measurement is possible.

According to the ninth aspect of the present invention, since the M-sequence signal has excellent correlation characteristics, the signal can be more reliably separated.

According to the tenth aspect of the present invention, since the modulation and the separation are performed using the pseudo random number signal, the separation of the signal is assured. Therefore, measurement sensitivity is high and highly accurate measurement is possible. In addition, if a plurality of types of transmission signals modulated by different pseudo-random number signals are generated and transmitted simultaneously, the measurement can be completed in a short time. Even in this case, since the signals can be reliably separated from each other, the measurement sensitivity does not decrease.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an internal configuration of an ultrasonic probe according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the signal generator.

3A and 3B are diagrams illustrating an arrangement of an ultrasonic transmitter and an ultrasonic receiver, wherein FIG. 3A is a diagram illustrating a state viewed from a back side;
(B) is a figure which shows the mode seen from the side surface side.

FIG. 4 is a block diagram showing an internal configuration of a signal separation device.

FIG. 5 is a conceptual diagram showing processing contents in the signal generator.

FIG. 6 is a conceptual diagram showing processing contents in the signal separation device.

FIG. 7 is a diagram showing a measurement principle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 ultrasonic detecting device 110 signal generating device 111 transmitter 112 pseudo-random number signal generator 113 modulation circuit 120 ultrasonic transmitting device 130 ultrasonic receiving device 140 signal separating device 141 signal distributor 142 correlator 150 data processing device 160 display device MS Pseudo random number signal P Object to be measured

Claims (10)

[Claims] 1. A signal of a predetermined frequency (hereinafter referred to as "carrier signal").
Transmitting means for generating a pseudo-random number signal; modulating means for generating a transmission signal by modulating the carrier signal using the pseudo-random number signal; A transmission unit that converts a transmission signal from the transmission unit into an ultrasonic wave and transmits the ultrasonic wave toward the measurement target; receives the ultrasonic wave transmitted by the transmission unit and reflected by the measurement target; A receiving unit that converts the signal into an electric signal (hereinafter, referred to as a “received signal”) and outputs the signal; and a separating unit that separates a signal included in the received signal by correlating the received signal with the pseudo random number signal. And data processing means for obtaining the position and / or shape of the measurement object by performing aperture synthesis on the signal separated by the separation means. A sound probe. 2. A signal of a predetermined frequency (hereinafter referred to as "carrier signal").
), Noise signal generating means for generating a plurality of types of pseudo-random number signals having no correlation with each other, and modulating the carrier signal using each of the pseudo-random number signals, thereby providing a plurality of types of transmission. A modulating means for generating a signal, a transmitting means comprising a plurality of transmitting units arranged at different positions from each other, and transmitting a different transmitting signal from each of the transmitting units to an ultrasonic wave and transmitting the ultrasonic wave toward the measuring object; A plurality of receiving units arranged at different positions from each other, each receiving the ultrasonic wave transmitted by the transmitting unit and reflected by the object to be measured, and receiving the ultrasonic wave by an electric signal (hereinafter, referred to as an electric signal). Receiving means for converting the received signal into a “received signal” and outputting the received signal; And a data processing unit for performing aperture synthesis on the signal separated by the separation unit to obtain the position and / or shape of the measurement target. An ultrasonic exploration device characterized by the above-mentioned. 3. The ultrasonic search device according to claim 2, wherein the transmitting unit transmits ultrasonic waves from a plurality of transmitting units at a time. 4. The ultrasonic search device according to claim 1, wherein the modulating means modulates a phase and an amplitude of the carrier signal. 5. The ultrasonic exploration device according to claim 1, wherein the pseudo random number signal is an M-sequence signal. 6. The ultrasonic search device according to claim 2, wherein a plurality of the transmission units are arranged around the reception unit. 7. A reception signal obtained by converting a signal obtained by modulating a carrier with a pseudo-random number signal into an ultrasonic wave, irradiating the ultrasonic wave toward a measurement object, and receiving a reflection thereof. An ultrasonic analyzer used in an ultrasonic probe that searches for a measurement target by analyzing a signal, wherein the received signal and the pseudo random number signal used for the modulation are input, and the received signal and the pseudo random number are input. A separating unit that separates a signal included in the received signal by correlating with the signal; and a position and / or shape of the measurement object by performing aperture synthesis on the signal separated by the separating unit. An ultrasonic analysis apparatus comprising: a data processing unit that obtains the following. 8. The ultrasonic wave according to claim 7, wherein said separation means is configured to be capable of inputting a plurality of pseudo-random number signals, and performs said separation for each pseudo-random number signal. Analysis device. 9. The ultrasonic analyzer according to claim 8, wherein the pseudo random number signal is an M-sequence signal. 10. An ultrasonic exploration method for irradiating an ultrasonic wave toward a measurement object and analyzing a received signal obtained by receiving the reflection to search the measurement object, wherein the ultrasonic wave detection method comprises: A transmission signal is generated by modulating a signal (hereinafter, referred to as a “carrier signal”) with a pseudo-random number signal, and the transmission signal is converted into an ultrasonic wave and transmitted to a measurement target, and reflected by the measurement target. Receiving the ultrasonic wave obtained, separating the signal contained in the received signal by correlating the received signal and the pseudo random number signal, and performing aperture synthesis on the separated signal, the measurement object Determining the position and / or shape of an object.