JPS5849141A - 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 This invention is based on the ultrasonic cutting device K, which has recently been used in hospitals etc. to diagnose internal tissue of patients.
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To explain it logically, the ultrasonic diagnostic apparatus is, as shown in FIG.
The ultrasonic transducer 2 is brought into close contact with the tube and driven by the drive circuit 8)/
The ultrasonic wave is driven to emit a /4 las ultrasonic wave into the subject l. This ultrasonic wave is then reflected by each tissue within the subject l. The reflected wave returns to the ultrasonic transducer 2 again, is converted into an electric signal, and is output as an echo signal. This echo signal is detected by a detection circuit 4 and its magnitude is detected. The time it takes for the ultrasonic waves to be emitted from the transducer 2 and return again depends on the distance to the reflector. Therefore, if the magnitude of an echo signal at a certain point in time takes a certain value, the depth k corresponding to that point in time is K if there is a tissue with a reflectance corresponding to that value. In this way, it is possible to know the state and sound inside the subject l.

By the way, the detection circuit 4 of the conventional ultrasonic diagnostic equipment is completely destroyed.
It is constituted by the D road. Therefore, since the echo signal usually accompanies the damped vibrating tube as shown in FIG. 2B, the detection output also detects this damped vibrating tube as shown in FIG. 2B. Since this damped vibration component is noise, the 87N ratio is a bad K. In addition, due to the overlap of these damped vibration components, distance resolution is also improved.

In view of the above, the present invention provides S
An object of the present invention is to provide an ultrasonic diagnostic apparatus that improves K/N ratio and distance resolution.

An embodiment of the present invention will be described below with reference to FIG. According to the present invention, the detection circuit is configured as shown in FIG. In this FIG. 8, the echo signal is single-wave rectified by the positive side single-wave rectifier (b) path 41. If the original echo signal is as shown in Figure 4, the output of the single-wave rectifier circuit 41 will be as shown in Figure 4. Then, this output is sent to the energy circuit 42 to produce the result as shown in FIG. 4C. On the other hand, the echo signal tube negative single wave rectifier R circuit 48 rectifies the single wave to obtain a single wave rectified output as shown in m4WJDK.

The delay circuit 42 is illuminated so that the output timings of the two waves 111 coincide with each other. Then, the output tube of the negative-confucian rectifier R circuit 48 is inverted, and both tubes are added by the adder circuit 44IC. Then, the output of the adder circuit 44 is as shown in Figure 4E! IIs is larger than the original echo signal (shown in Figure 4), and the time during which the damped oscillation occurs is also shorter.The output of this adder circuit 44 is input to the rhonus filter 46. Extract only low frequency components, #I
! A signal tube corresponding to the envelope of Figure 4 is obtained and this signal is amplified by amplification@46.

It is assumed that the echo signal is accompanied by a damped vibration tube and has a length of two wavelengths as shown in FIGS. 2 and 4. Then, all the conventional auiR (ro) roads are shown in Figure 2 BK.
As shown in FIG. 4, the length corresponding to two wavelengths is detected in OK, whereas in the configuration shown in FIG. 8, the length of KL6 is detected as shown in FIG. 4. Therefore, the time period during which the damped vibration continues is shortened, the degree to which the damped vibrations of the ridges overlap is reduced, and the distance resolution can be improved. Furthermore, as shown in FIG. 4 WFC, the amplitude can be emphasized, and the 87N ratio is improved.

Note that when the reflected ultrasound wave propagates through the object and is attenuated, the attenuation of high frequencies is severe, so the center frequency of the echo signal shifts to a lower value as the distance to the reflector increases. It's coming.

j this! [Then, the time period of the luck circuit 42 is gradually lengthened from the first echo signal obtained to the last echo signal, and the distance to the reflector becomes longer and the center frequency of the echo signal becomes lower. Even on a platform with a longer length, it is preferable to always make the timings of the outputs of both single-wave regulating aa-a-paths 41 and 48 the same.

As described above with respect to the embodiments, according to the present invention, single-wave mat is performed for each of the positive and negative echo signals i, and one wave tMa is performed, and the polar tubes are aligned and added, so that the distance resolution can be improved. Improvement and improvement of 81N ratio and t
(2) Can.

[Brief explanation of the drawing]

Chapter iv! J is a schematic diagram for explaining the principle of an ultrasonic diagnostic device, 112 diagrams are waveform diagrams for explaining the operation of a conventional detection circuit, and Figure 88 is a diagram showing the configuration of a detection circuit according to an embodiment of the present invention. The f ay diagram shown in FIG. 4 is the ninth waveform diagram explaining the operation of the jIB diagram. 1--Subject, 2--Ultrasonic transducer, 8--
・Drive circuit, 4...Detection #L circuit, 41.48・
...One wave! 1151 circuit, 42-... slow-acting circuit, 44-
-210 calculation 0011.45...Ronogusu 2 Iruta,
46...Amplifier. Applicant Shimadzu Chosakusho Co., Ltd. Answer 3 Japanese paper 9 illustrations

Claims (1)

[Claims] (1) Ultrasonic waves are emitted into the subject, and the reflected waves reflected by various tissues within the subject are received and converted into electrical signals;-
In an ultrasonic diagnostic device that obtains a signal and detects the echo signal using a detection circuit to detect the magnitude of the echo signal,
The detection circuit tube includes a positive side single-wave rectifier flL circuit, a negative side single-wave rectifier circuit, and a delay circuit that delays the output of one of these single-wave rectifier circuits to match the timing of the output of the other single-wave rectifier flL circuit. The circuit and this j! It consists of an adder circuit that adds the output of one single-wave rectifier circuit and the output of the other single-wave rectifier circuit connected to the extension tube with their polarities aligned, and a low-pass filter that filters the output of this adder circuit with a λ force. An ultrasonic diagnostic device featuring a tube.