JPS61187845A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic probe capable of measuring the softness of living tissue.

BACKGROUND OF THE INVENTION Recently, the softness of biological tissues has been frequently measured in fields such as dentistry. For example, Inter
national dental journal, V
ol 21.

PP 430-441 (W, L, KYDD et al.) describes the construction of a system for measuring the softness of periodontal mucosal tissue.

Hereinafter, a conventional measurement system will be explained with reference to FIG. In FIG. 4, 101 is an ultrasonic transducer made of piezoelectric ceramics, etc., 102 is a cylinder glued to the ultrasonic transducer 1o1, 103 is a lever connected to the cylinder 102, and 104 is a lever 10.
It is a fulcrum located at the center of gravity of No. 3. Arrow 105 is the position of the load on cylinder 1o2, 106 is the periodontal mucosa, 1
07 is hard tissue such as alveolar bone.

First, when the load on the cylinder 1o2 at the arrow 105 is zero, the periodontal mucosa 1 of the cylinder 102
The fulcrum 104 is arranged so that the load on the fulcrum 106 is zero. In this case, the periodontal mucosa 106 is
It is possible to measure the thickness of That is, the ultrasonic pulses generated by the ultrasonic transducer 101 are transmitted to the cylinder 102.
Transparent. The cylinder 102 is made of a material, such as polystyrene, whose acoustic impedance is close to that of biological soft tissue, and there is little reflection of sound waves at the contact surface between the cylinder 102 and the periodontal mucosa 106. The ultrasonic pulse that has passed through the periodontal mucosa 106 is reflected at the interface of the hard tissue 107, and is converted into an electric pulse in the ultrasonic transducer 1o1.

The interval between these electric pulses is converted into the thickness of the periodontal mucosa 106. This measurement method is widely known in the field of medical ultrasound technology. Next, when a predetermined load is applied as indicated by arrow 105, the periodontal mucosa 106 deforms thinly, but the hard tissue 107 hardly deforms. Therefore, it is possible to measure the thickness of the periodontal mucosa 106 when a load is applied, that is, the softness of the tissue.

Problems to be Solved by the Invention However, in the above configuration, in order to obtain a change in the thickness of the soft tissue that corresponds to a change in load, it is necessary to Changes had to be constantly recorded, which was a practical problem.

The present invention solves the above-mentioned problems of the prior art, and aims to facilitate the measurement of the interval of electric pulses corresponding to changes in load or changes in pressure at a contact surface.

Means for Solving the Problems The present invention achieves the above object by providing a display control section for simultaneously displaying changes over time in the received signal from the ultrasonic transducer and the output signal from the pressure detection sensor/transducer on the display section. The goal is to achieve the following.

According to the above-mentioned structure, the present invention simultaneously displays changes in the received signal from the ultrasonic transducer and the output signal from the pressure detection sensor over time on the display section, thereby displaying changes in the thickness of the soft tissue corresponding to changes in load on the display section. This allows you to read the softness.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention.

In Fig. 1, 11 is an ultrasonic probe that transmits and receives ultrasonic waves to and from the subject, and 12 is a pressure sensor that is connected to the ultrasonic probe and detects the load substantially applied to the subject, which is indicated by an arrow. 13 is a load on the pressure sensor 12, 14 is an output signal of the pressure sensor 12, 16 is a transmitting/receiving circuit connected to the ultrasound probe 11, 16 is a timing generator for controlling the timing of each part of the ultrasound diagnostic apparatus, 17 18 is a display control unit; 19 is a daily control input to the display control unit; 20 is a signal processing circuit that processes the output signal 14;
1 is the pulse output of the signal processing circuit 2o, 22 is a mixer for mixing the detection output 23 of the transmitting/receiving circuit 15 and the pulse output 21, and 24 is a two-dimensional display unit including a CRT. The mixer 22 . Each output of the Y-axis sweep signal generation unit 171 and the display control unit 18 is a luminance signal, a Y-axis sweep signal,
Added as an X-axis sweep signal.

The operation of the above configuration will be explained below.

First, the transmitting/receiving circuit 15 generates a transmitting pulse based on a transmitting timing signal generated by the timing generator 16. The transmitted pulse is transmitted to the ultrasound probe 11 and converted into an ultrasound pulse. The ultrasonic pulse propagates through the soft tissue 3o, is reflected on the surface of the hard tissue 31 and becomes an echo pulse, which is converted into a received signal by the ultrasonic probe 11. The received signal is detected by the transmitter/receiver circuit 15. It is possible to convert the thickness of the soft tissue 3o from the pulse interval of the detection output 23 and the sound wave propagation velocity of the soft tissue 3o. Probe 11 and soft tissue 3o
The pressure on the contact surface is determined from the output signal 14 generated by the load 13 applied to the pressure plate 12. Signal processing circuit 2
0 changes the transmission timing and the interval between pulse outputs 21 in accordance with the voltage level of the output signal 14. Pulse output 2
1 and the detection output 23 are mixed by a mixer 22. The Y-axis sweep circuit 17 generates a sawtooth wave synchronized with the transmission pulse, and therefore displays the pressure on the surface of the soft tissue 30, the boundary between the soft tissue 30 and the hard tissue 31, and the contact surface on a line segment parallel to the Y-axis of the display unit 24. Corresponding information is displayed as a bright spot. Next, the line segment moves in the X-axis direction due to the sawtooth wave generated by the display control section 18. The timing of sawtooth wave generation is determined by human control19
added to.

In this way, the display control section 18 can simultaneously display the output signal 14 of the pressure sensor 12 and the temporal change of the received signal on the display section 24.

As is clear from the above description, according to this embodiment, it is possible to simultaneously display the temporal changes in the output signal 14 of the pressure sensor 12 and the received signal of the ultrasonic probe 11 on the display section 24. The change in the thickness of the soft tissue 30, ie, the softness, can be easily determined from the display section 24.

In the above explanation, the display control unit 18 generates a simple sawtooth wave, but when the change in the load 13 is step-like, the display control unit 18 is generated at the timing of the change in the load 13 as shown in FIG. A control method can be considered. The purpose of this method is to display the state of the received signal not only after the change in the load 13 but also before the change at a predetermined position on the display section 24, thereby making it easier to understand the change in the received signal over time. It's about doing. Figure 2 shows the timing relationship of the display control unit 18, and the horizontal axis corresponds to time t. a in the diagram
is the waveform of the output 181 of the display control unit 18, b is the waveform of the control input, and C is the waveform of the output signal of the pressure sensor 12. Waveform a is different from a simple sawtooth wave. That is, the output 181 of the display control unit 18 starts to rise due to a change in the control force 19 at the timing. The received signal displayed during this rise is before the change in load 13 occurs.

After that, at timing B, the output 181 becomes a constant value. Next, the timing C of the change in the output signal 14 of the pressure sensor 12 is waited for. From timing B to timing C, the image displayed on the display section does not change. After timing C, the output 181 rises again, and the display section 24 displays a received signal corresponding to such a change in the load 13.

That is, the change in the thickness of the soft tissue 3o is displayed. A second example of an image displayed on the display unit 24 with such a timing relationship is shown below.
Shown in Figure B. In the figure, 41 indicates the ultrasound probe 11 and the soft tissue 30.
42 is the image corresponding to the boundary position of the soft tissue 3o and the hard tissue 3
1 corresponds to the boundary position, 43 corresponds to the output signal 14 of the pressure sensor 12, and d corresponds to the thickness of the soft tissue 3o.

Since the thickness d has an important meaning in actual measurement, image 4
1.42 only needs to clarify the relative distance relationship between the tissue boundary positions, and in the example of this figure, the ultrasound probe 11 and the soft tissue 3
An image 41 corresponding to the boundary position of o is displayed parallel to the X axis of the display section 24. B from the timing person on the display section 24
Until then, the load 13 is constant and the thickness of the soft assembly @ 30 does not change. From timing B to C, output 1 of the display control section
Since 81 is constant, the image on the display section 24 remains constant. Next, the pressure cassette/su1 due to a step change in the load 13
After timing C of the change in the output signal 14 of No. 2, a change in the thickness of the soft tissue 30 is shown. In this way, the soft tissue 3
The main part of the pressure change corresponding to the thickness of o is displayed on the display section 240.
It becomes possible to display it at a predetermined position. In order to determine the softness from the image in FIG. 2B, it is sufficient to read information such as the amount of change in the thickness d of the soft tissue 3° with respect to the magnitude of the load 13.

FIG. 3 is a block diagram of the main parts of the display control section in the second embodiment of the present invention.

In the display control section 18 surrounded by a broken line in FIG.
51 is a counter for counting clock pulses from the timing generator 16; 52 is a reference table for converting the output N of the counter 51 to M; For example, a logarithmic function relationship, M=CXLOG(N) (1), is given between N and V. However, C is an arbitrary constant, and the relationship between V and H is not limited to the function of equation (1). For example, M = V/7 (
2) It may also be a function like . That is, any function may be used as long as the -th derivative is a monotonically decreasing function of the independent variable, H here. Such a function is called here logarithmic. The reference table 52 can be configured with a read-only memory or the like. 63
is a D/person converter for converting the output of the lookup table 52 into an analog value. The output of the reference table 52 is a digital logarithmic sweep signal, and the output of the D/person converter 63 is an analog logarithmic sweep signal. If a display control unit that generates such a logarithmic sweep signal is used, it becomes easier to understand temporal changes in soft tissue thickness based on step-like pressure changes on the display unit. In other words, the sweep speed of the display control unit is fast for sudden changes in soft tissue thickness immediately after a step-like pressure change, but the sweep speed is slow when relatively time has elapsed and changes in soft tissue thickness have decreased. , the temporal change in soft tissue thickness appears relatively linear on the display, making it easy to grasp the main part of the temporal change.

Note that in the above embodiments, a CRT was used as the display unit, but it may also be a display unit such as a printer. Also, the output of the pressure sensor is shown as an image on the display.

It may also be displayed as a numerical value.

Effects of the Invention As described above, the present invention provides a display control unit that simultaneously displays the output signal of the pressure sensor connected to the ultrasound probe and the reception signal of the ultrasound probe, thereby making it possible to By making it possible to simultaneously record the load on and the change in thickness over time, it facilitates the measurement of the softness of soft tissues, which is highly effective. Furthermore, the display control section generates a sweep output that makes it easy to understand the main parts of changes over time, which is even more effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an ultrasonic diagnostic apparatus in a first embodiment of the present invention, FIG. 2 is a block diagram of a display control unit in the second embodiment of the present invention, and FIG. 1 is an overview diagram of a conventional ultrasonic diagnostic apparatus. 11... Ultrasonic probe, 12... Pressure sensor, 15... Transmission/reception circuit, 16...
・Timing generation section, 17... Y-axis sweep signal generation section, 18... Display control section, 2o...
Signal processing circuit, 22... Pexa, 24...
・Display section. Name of agent: Patent attorney Toshio Nakao
21! 1 24...Moat Ho Shuttle No. 3 Figure 4 Procedure amendment (method) % formula % 1 Display of case 1985 Patent Application No. 29552 2 Name of invention Ultrasonic diagnostic device 3 Case of person making amendment Relationship with Patent application
Colonel Tokoro 1006 Kadoma, Kadoma City, Osaka Prefecture
Name (582) Matsushita Electric Industrial Co., Ltd. Representative Toshihiko Yamashita 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 6 Amendment Order 7, Details of Amendment, Page 2 1st line - 2nd line r International - (W, L, KY
International den.
tal Journal VoL21. PP430-44
1 (W, L, KYDD et al.) Correct with others.

Claims (2)

[Claims] (1) An ultrasonic probe that transmits and receives ultrasonic waves to and from the subject, a pressure sensor that detects the load substantially applied to the subject, and a display that displays the received signal of the ultrasonic probe. and a display control section for simultaneously displaying an output signal of the pressure sensor and a change over time of the received signal on the display section. (2) The ultrasonic diagnostic apparatus according to claim 1, wherein the display control section generates a logarithmic sweep signal.