JPH0226969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ultrasound-based language function diagnosis device, and in particular, an ultrasound-based language function diagnosis device that is capable of obtaining a visual image of the tongue profile associated with pronunciation. Regarding.

(Technical Background of the Invention) Various types of ultrasonic diagnostic devices are known.
Mode devices and M-mode devices that display the movements of various parts of the circulatory system are known ('84ME Equipment Technology Overview, Denshi Keizoku Publishing Co., Ltd., April 1, 1984).

As shown in FIG. 6, these devices continuously display reflected pulses 61, 62, and 63 obtained by reflecting an emitted pulse 60 from a probe inside the body on a cathode ray tube or the like.

Since the purpose of such an apparatus is to obtain an accurate tomographic image, it is expected that the scanning period of the probe can be shortened and that even small reflected pulses can be accurately depicted. Regarding this, the above-mentioned publication states, ``When creating a static ultrasound image of the heart in synchronization with the heartbeat, if one screen is created in a short period of less than 30ms in synchronization with the heartbeat, it will be possible to Even for parts that move rapidly, images that can be regarded as cross-sections at a certain instant can be obtained.Such images can be captured at 30 times per second
If you make a few pieces, you can observe the heart in its natural state. "It has said.

Conventional devices of this type have recently been used for the diagnosis and correction of language function.

In other words, if there is some kind of language disorder, the shape of the tongue when pronouncing a certain sound (for example, "a") is measured, and the abnormality or disorder can be determined by measuring the shape of the tongue when pronouncing it normally. Diagnosis can be made by comparing. Furthermore, pronunciation training can be performed by showing the disabled person the shape of the tongue required for normal pronunciation.

For this purpose, in order to judge the state of abnormal pronunciation from the shape of the tongue and conduct training, it is necessary to know only the basic shape (profile) of the tongue, and it is necessary to understand the ever-changing tongue profile. It is necessary to know the average shape of

However, according to the conventional device described above, since the purpose is to observe the movement of human body tissues and organs in detail, the signals regarding the detailed parts of the human body tissues get in the way, making it difficult to grasp the accurate tongue profile. It was difficult. Furthermore, as mentioned above, although it is possible to observe moving tissues using the M-mode device, even if you observe the moving state of the tongue, it is difficult to practice pronunciation using this device. This was not possible since the tongue profile was not shown.

(Purpose of the Invention) This invention was made in an attempt to eliminate the above-mentioned drawbacks of the prior art, and displays only the tongue profile for a specific pronunciation, thereby facilitating the diagnosis of language function abnormalities and pronunciation training. The purpose of the present invention is to provide a language function diagnosis device using ultrasonic waves.

(Summary of the invention) In order to achieve this object, according to this invention,
The current data of the reflected signal obtained by scanning the ultrasound probe is averaged with the past data for each scan, and the maximum value of this average value for each scan is interpolated to depict the tongue profile. I'll do what I do.

(Embodiments of the invention) Examples of the invention will be described below with reference to the accompanying drawings. Note that in each figure, the same reference numerals indicate similar objects.

FIG. 1 shows an embodiment of the invention.

In the figure, 10 is an ultrasound probe, 11 is a transmission circuit, 12 is a scanning circuit, 13 is a pre-signal processing circuit, 14 is an AD converter, 15 is an image signal forming circuit, 16 is a video signal processing circuit, and 17 is a display. The circuit 18 is a control circuit.

The probe 10 emits ultrasonic waves of a specific frequency, and various types of probes are known for medical use. This type of probe has both transmitter and receiver functions in one unit, and is connected to the lower jaw 2 as shown in Figure 2.
0 and perform measurement.

Ultrasonic waves are reflected at the interface when there is a change in the acoustic impedance of the medium through which they are transmitted. The impedance of the human body's muscle tissue is close to that of water, and is approximately 4000 times the impedance of the air layer assumed at the upper edge of the tongue, resulting in a large level of reflected waves. Additionally, although there is an impedance difference within the tissue of the tongue, it is not at the same ratio as between the tongue and the air, and the level of the reflected wave is extremely small. Furthermore, when the tongue is in contact with the palate, reflected waves from the palatal bone 21 are obtained, but the impedance of the bone is approximately four times that of water, and the level of the reflected waves is lower when the upper edge of the tongue is an air layer. It doesn't get bigger. In this case, information is obtained that the upper edge of the tongue of interest is located close to the palatine bone.

Such a probe 10 can be scanned by various electronic methods as shown in FIG. 3 while being held in the position shown in FIG. That is, FIG. 3a shows the linear scanning method. Here, the probe 10 includes a plurality of vibrators 10A, 10
B, 10C, ... and electronic switches SW1, SW2, connected in series with these, respectively.
It has SW3...

The scanning circuit 12 sequentially turns on one of the electronic switches (switch SW3 in the figure).
In synchronization with this, the transceiver section 31 activates the corresponding vibrator.

In contrast, FIG. 3b shows a sector scanning method. In this case, a plurality of vibrators 10A, 10B, 1
0C, . . . are provided with delay means DL1, DL2, DL3, . . . each driven by a scanning circuit 12. The delay time of each delay means can be changed by the scanning circuit 12. Moreover, since a common signal is inputted to each delay means from the transmitting/receiving section 31, one wavefront 36 is formed by the delay characteristics of the delay elements DL1, DL2, DL3, . Therefore, by continuously changing the delay characteristics of the delay means by the scanning circuit 12, the probe 1
Scanning can be performed by continuously changing the angle θ of the normal N2 of the wavefront 36 with respect to the normal N1 of 0 from +45 degrees to more than -45 degrees.

The transmitting circuit 11 is for energizing the probe 10 and causing it to emit ultrasonic waves of a predetermined frequency. Further, the scanning circuit 12 performs scanning similar to that described in FIG. 3.

The pre-signal processing circuit 13 performs waveform shaping and amplification of the received signal. In particular, a function that increases the gain of the amplifier immediately after pulse transmission to compensate for the attenuation of reflected waves due to distance, a logarithmic amplification function that makes it possible to handle reflected signals with a wide dynamic range, and It has a detection function to obtain amplitude information.

The AD converter 14 converts the output signal of the pre-signal processing circuit 13 into a digital signal.

The image signal forming circuit 15 is as shown in FIG. According to the figure, the circuit 15 includes a buffer memory 41, an averaging processing circuit 42, and a data memory 4.
3. Maximum distance calculation circuit 44, buffer memory 4
5, and an interpolation processing circuit 46.

The buffer memory 41 is for temporarily storing data obtained by each scan. The contents of this buffer memory 41 are sequentially transferred to the averaging processing circuit 42. Therefore, the current data is held in the buffer memory 41,
The data memory 43 stores past addition average data.

The averaging processing circuit 42 includes a buffer memory 41
The data characteristics are extracted from the current data and the past addition average data of the data memory 43, and the S/N is
This is an effective circuit for improving. That is,
Considering that the object of measurement or diagnosis by the device of this invention is the constantly moving tongue, the proportion of previous data in the calculation result decreases exponentially. Y _o = Y _o-1 + (X _o −Y _o-1 )/K (where, Y _o is the current calculation result, Y _o-1 is the previous calculation result, X _o is the current data, and K is the addition weight). It is in line with the purpose to calculate .

In the above equation, since the signal is input regularly, the calculation result is such that the signal level is maintained. However, in the case of noise, since the signal is irregular, the calculated result will be lower than the level at the time of sampling. Therefore, the S/N of the reflected signal is improved and features are extracted, making it easier to identify the upper edge of the tongue and the palatine bone.

For example, assume that curves 51 and 52 in FIG. 5 are profiles in the longitudinal direction A of the tongue (FIG. 2) at certain moments T1 and T2 when pronouncing "a". Here, the tongue position in the scanning direction (arrow T1) at time T1 and the tongue position in the scanning direction (arrow T2) at time T2 belong to completely different profiles, and these positions cannot be connected. But I can't get any meaningful profile. For this purpose, the method of averaging is used to create a relationship between current and past data.

The data memory 43 is a memory capable of storing averaged data for each scanning direction specified by the scanning circuit 12 that drives the probe 10, and has a memory area of a predetermined bit (for example, 128 bits) for each direction. . According to the present invention, it is only necessary to specify, for example, eight scanning directions, so the memory area also becomes eight.

The maximum distance calculation circuit 44 is a circuit for specifying the position of the tongue in each scanning direction. for example,
Scanning direction T1 in profile curve 51 in FIG.
Since there are various types of reflected waves also in , the received waveforms are as shown in waveforms 61, 62, and 63 in FIG. Therefore, for the reason mentioned above, the signal having the maximum level is extracted as the signal corresponding to the position of the tongue (signal 62 in FIG. 6). Also, at this time,
Since the range of a certain distance of the tongue can be predicted in advance, it is effective to limit the range within the predictable range when determining the maximum level. For this reason,
The maximum distance calculation circuit 44 sequentially compares each data in the same scanning direction and extracts and calculates the largest one.

The buffer memory 45 includes the maximum distance calculation circuit 44
The output signals of , that is, the signals corresponding to the position of the tongue in each scanning direction, are accumulated for all scans of one measurement.

The interpolation processing circuit 46 forms an image signal corresponding to one curve passing through each point indicated by this data, based on all the position data accumulated by the buffer memory 45 in one measurement. This image signal is converted into an analog signal by a video signal processing circuit 16, subjected to luminance modulation, etc., and displayed on a display circuit 17 such as a CRT.

FIG. 7 shows such a display. "×" by 8 sampling scans from S1 to S8
Data corresponding to each point indicated by a mark is obtained, and a single curve 70 passing through each point is displayed as a tongue profile corresponding to a certain pronunciation. In addition,
At this time, skull data as shown in FIG. 2 may be stored in advance in the video signal processing circuit 16, and the data may be combined with the curve 70 in FIG. 7 and displayed.

The timing of scanning and sampling as described above is determined by command signals a to f of the control circuit 18.

Next, the operation of this embodiment will be explained with reference to the flowchart of FIG. In the following explanation, numbers (81) to (92) correspond to the numbers of each step in the flowchart.

When the apparatus starts capturing (81), the control circuit 18 sets the probe 10 at the initial position so that it can emit ultrasonic waves using the command signal b.
Subsequently, the control circuit 18 sends out a command signal a, and the transmitting circuit 11 energizes the probe 10 to emit ultrasonic waves (82).

At the same time that the transmitting circuit 11 is activated by the command signal a, command signals c, d, and e are also sent out, and the AD converter 14 starts sampling the received signal (83).

When a digital signal is formed by this sampling (83), the image signal forming circuit 16 executes averaging processing (84) and maximum distance calculation processing (85), and stores the results in the buffer memory 45 (Fig. 4).
accumulates in (86).

At this timing of storage in the buffer memory 45, the control circuit 18 checks whether scanning in eight predetermined directions has been completed (87). If the number of scans has not reached 8, control circuit 1
8 sends command signals a and b, changes the scanning direction (88), and executes the above-described utterance-memory storage cycle again.

When all the scanning is completed in this way, the contents stored in the buffer memory 45 are read out (89), and the above-mentioned complementation process is executed using this data (90).
The results will be displayed (91), the capture process will be completed (92), and these will be repeated in sequence.

In addition, in the above embodiment, the case where the profile of the tongue in the longitudinal direction is obtained was explained.
Of course, by changing the scanning direction of the probe, it is also possible to obtain a profile in the width direction of the tongue. Furthermore, two types of probes, one in the length direction and the other in the width direction, may be provided. Furthermore, it goes without saying that the number of scans is not limited to eight times.

(Effects of the Invention) This invention averages the current data of the reflected signals obtained by scanning the ultrasonic probe with the past data for each scan, and calculates the maximum value of this average value for each scan. By depicting the tongue profile using data that interpolates values, it is possible to obtain a language function diagnosis device using ultrasound that has the following effects.

(1) Only the tongue profile can be clearly shown.

(2) As a result of the above, abnormalities in the tongue profile of speech-impaired people can be diagnosed and can be useful for correction.

(3) Even if used for a long time, it has no effect on the human body like X-rays and is highly stable.

(4) Since fewer scanning directions are required, the memory can be made smaller.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an embodiment of this invention, Fig. 2 is an explanatory diagram showing how the probe is set, Fig. 3 is an explanatory diagram showing how the probe scans, and Fig. 4 is an embodiment of the invention. Fig. 5 is an explanatory diagram of the relationship between temporal changes in the tongue and sampling when sampling the tongue profile, Fig. 6 is a diagram of the relationship between transmitted pulses and received reflected pulses, and Fig. 7 8 is an explanatory diagram of an image drawn by an image signal obtained by interpolation processing, and FIG. 8 is a flowchart for explaining the operation of the embodiment of the present invention. 10... Ultrasonic probe, 11... Transmission circuit, 12
...Scanning circuit, 13...Pre-signal processing circuit, 14...
AD converter, 15...Image signal forming circuit, 16...Video signal processing circuit, 17...Display circuit, 18...Control circuit, 41, 45...Buffer memory, 42...Averaging circuit, 43...Data memory, 44...Maximum distance Arithmetic circuit, 46...interpolation processing circuit.

Claims (1)

[Scope of Claims] 1. A probe capable of transmitting and receiving ultrasonic waves with respect to the oral cavity, a transmitting means for energizing the probe to transmit ultrasonic waves, and reflection of the ultrasonic waves emitted by the probe in the oral cavity. receiving means for forming an image signal based on a reflected signal obtained by receiving waves with the probe; In a language function diagnosis device for diagnosing a language function, the receiving means adds and averages current data of the reflected signal obtained by scanning the probe to past data for each scan, and calculates the average value for each scan. 1. A language function diagnostic device using ultrasound, characterized in that data for interpolating the maximum value of is output as the image signal.