JPH05138A - Ultrasonic diagnosing apparatus - Google Patents

Abstract

PURPOSE:To enable the judging of whether an ultrasonic probe is left alone in the air or not accurately by detecting reflection of an ultrasonic wave with an acoustic lens to control the transmission of waves from the ultrasonic probe according to an output of the detection. CONSTITUTION:When an ultrasonic probe 4 is left alone in the air, an ultrasonic wave is reflected in multiplicity with a rubber lens. At this point, a signal A is inputted into a wave form shaping section 10 and a signal B is outputted from the waveform shaping section 10. A pulse generating section 12 outputs a pulse of a signal D as the signal B becomes larger than a specified level T when a gate signal C is at 'H'. When the signal D is inputted, a pulse width judging section 13 outputs a transmission checking signal as pulse widths P1, P2 and P3 are equal. This enables accurate detection of how the ultrasonic probe is left alone in the air thereby preventing heating and characteristic degrading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus equipped with an ultrasonic probe having an acoustic lens.

[0002]

2. Description of the Related Art When an ultrasonic probe is left in the air for a long time, the vibration energy of the piezoelectric element is not released and the ultrasonic probe heats up and deteriorates its characteristics.

In order to prevent this, for example, Japanese Patent Laid-Open No. 63-63
The ultrasonic diagnostic apparatus disclosed in Japanese Patent No. 122429 is proposed. In the ultrasonic diagnostic apparatus disclosed in Japanese Unexamined Patent Publication No. 63-122429, as shown in FIG. 7, a signal waveform a received when an ultrasonic probe is applied to a living body.
Then, while the signal level is high in both the sample period g1 and the sample period g2, in the signal waveform b received when the ultrasonic probe is left in the air, the signal level in the sample period g2 is smaller than that in the sample period g1. Paying attention to the point that the signal level of 1 is significantly reduced, it is determined whether or not the ultrasonic probe is left in the air. And
When it is determined that the ultrasonic probe is left in the air, the driving of the ultrasonic probe is interrupted.

[0004]

In the above-described conventional ultrasonic diagnostic apparatus, it is determined whether or not the ultrasonic probe is left in the air by paying attention to the signal levels in the sampling periods g1 and g2. However, even when the ultrasonic probe is applied to the living body, if the portion corresponding to the sample period g1 is living tissue and the portion corresponding to the sample period g2 is water inside the living body, the received signal waveform is as shown in FIG. The signal waveform becomes like the waveform d, and it is erroneously determined that the ultrasonic probe is left in the air. That is, there is a problem that it is not certain to determine whether or not the ultrasonic probe is left in the air.

Therefore, an object of the present invention is to provide an ultrasonic diagnostic apparatus for accurately determining whether or not the ultrasonic probe is left in the air and controlling the transmission of the ultrasonic probe.

[0006]

An ultrasonic diagnostic apparatus of the present invention is an ultrasonic diagnostic apparatus equipped with an ultrasonic probe having an acoustic lens, and a reflection detecting means for detecting reflection of ultrasonic waves by the acoustic lens, and It is characterized in that it comprises a wave transmission control means for controlling the wave transmission of the ultrasonic probe in accordance with the output of the reflection detection means.

[0007]

When the ultrasonic probe having the acoustic lens such as rubber is applied to the living body, the ultrasonic wave propagates in the living body without causing multiple reflection of the ultrasonic wave in the acoustic lens. However, when left in the air, multiple reflection of ultrasonic waves occurs in the acoustic lens. Therefore, in the ultrasonic diagnostic apparatus of the present invention, the reflection of the ultrasonic wave by the acoustic lens is detected by the reflection detecting means to determine whether or not the ultrasonic probe is left in the air. Then, when it is determined that the ultrasonic probe is left in the air, the transmission control unit suspends or suppresses the transmission of the ultrasonic probe.

As described above, since attention is paid to the reflection of ultrasonic waves by the acoustic lens, it can be accurately determined whether or not the ultrasonic probe is left in the air.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the embodiments shown in the drawings. However, this does not limit the present invention. FIG. 1 is a block diagram of essential parts of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

In this ultrasonic diagnostic apparatus 1, the transmission beamformer 3 transmits ultrasonic waves from the ultrasonic probe 4 in synchronization with the system trigger generated by the system trigger generator 2. The ultrasonic echo signal is received by the ultrasonic probe 4, passed through the reception beamformer 5, the filter logarithmic compression unit 6, and input to the DSC 7. Then, an image is generated by the DSC 7 and displayed on the CRT 8.

The waveform shaping section 10 is a filter circuit that removes ringing and noise from the output signal of the filter logarithmic compression section 6 and extracts only a high signal level portion.
The gate signal generator 11 is the system trigger generator 2
"H" for a predetermined period from the system trigger signal generated by
Output the gate signal of. Further, the predetermined time can be adjusted so that multiple reflection of ultrasonic waves by the acoustic lens can be detected. The pulse generating section 12 outputs a pulse when the output signal of the waveform shaping section 10 becomes higher than a predetermined level when the gate signal is “H”.

The pulse interval determination unit 13 measures the intervals of the pulses, and when three or more pulses are continuously arranged at equal intervals, determines that the ultrasonic probe 4 is left in the air and sends it to the transmission beamformer 3. Output the wave suppression signal. on the other hand,
If 3 or more consecutive pulses are arranged at unequal intervals, the ultrasonic probe 4
Is determined to have been applied to the living body, and the output of the transmission suppression signal to the transmission beamformer 3 is stopped.

The transmission beamformer 3 transmits the ultrasonic wave from the ultrasonic probe 4 in synchronization with the system trigger as described above while the transmission suppression signal is not input. While is input, ultrasonic waves are transmitted from the ultrasonic probe 4 in synchronization with once every 100 times of the system trigger, and the rest 99 times are paused. 1
It may be done once per frame.

The ultrasonic probe 4, the reception beam former 5, the filter logarithmic compression unit 6, the waveform shaping unit 10, the gate signal generation unit 11, the pulse generation unit 12, and the pulse interval determination unit 13 constitute reflection detection means. Further, the transmission beam former 3 constitutes a transmission control means.

Now, FIG. 2 shows a state in which the ultrasonic probe 4 is applied to a living body. As shown by α in FIG. 2, the ultrasonic waves are emitted from the piezoelectric ceramics 4a, transmitted through the matching film 4b and the rubber lens 4c, and travel inside the living body F. At this time, the signal A as shown in FIG. 3 is input to the waveform shaping section 10, and the signal B as shown in FIG. 3 is output from the waveform shaping section 10. The pulse generator 12 outputs the pulse of the signal D as shown in FIG. 3 when the signal B as shown in FIG. 3 becomes higher than a predetermined level T when the gate signal C as shown in FIG. 3 is “H”. .. Pulse interval determination unit 1
3, when the signal D of FIG. 3 is input, the pulse interval P1,
Since P2 is not equal, the transmission suppression signal is not output. Therefore, the transmission beam former 3 transmits ultrasonic waves from the ultrasonic probe 4 in synchronization with the system trigger.

Next, FIG. 4 shows a state in which the ultrasonic probe 4 is left in the air. The ultrasonic wave is α1,
As indicated by α2, multiple reflection is performed by the rubber lens 4c.
At this time, the signal A as shown in FIG. 5 is input to the waveform shaping section 10, and the signal B as shown in FIG. 5 is output from the waveform shaping section 10. The pulse generator 12 outputs a pulse of the signal D as shown in FIG. 5 when the signal B as shown in FIG. 5 becomes higher than a predetermined level T when the gate signal C as shown in FIG. 5 is “H”. .. When the signal D in FIG. 5 is input, the pulse interval determination unit 13 outputs the transmission suppression signal because the pulse intervals P1, P2 and P3 are equal. Therefore, the transmission beamformer 3 transmits an ultrasonic wave from the ultrasonic probe 4 in synchronization with the system trigger once every 100 times, and the subsequent 9
It has been paused nine times. Therefore, heat generation of the ultrasonic probe 4 is suppressed. The ultrasonic wave is transmitted from the ultrasonic probe 4 only once every 100 times of the system trigger is to detect that the ultrasonic probe 4 is applied to the living body again and stop the output of the transmission suppression signal. This is because it automatically returns to the state of.

The level T is set to such a level that a signal based on the fourth multiple reflection can be exceeded, for example.

In another embodiment, the transmission beamformer 3 lowers the transmission power by the transmission suppression signal.

As still another embodiment, as shown in FIG. 6, the period of the gate signal C at "H" is set to the first and / or
Alternatively, it is set short enough to receive a signal based on the second multiple reflection, and when the signal B input during that period exceeds a predetermined level T, the pulse interval determination unit detects it as multiple reflection by the acoustic lens. There are things.

[0020]

According to the ultrasonic diagnostic apparatus of the present invention, it is possible to accurately detect the state where the ultrasonic probe is left in the air. Moreover, since the transmission of waves from the ultrasonic probe is controlled thereby, heat generation and characteristic deterioration can be reliably prevented.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts of an embodiment of an ultrasonic diagnostic apparatus of the present invention.

FIG. 2 is an explanatory diagram showing a state where an ultrasonic probe is applied to a living body.

FIG. 3 is a waveform diagram of signals at various parts of the apparatus of FIG.

FIG. 4 is an explanatory diagram showing a state where the ultrasonic probe is left in the air.

FIG. 5 is a waveform diagram of signals at various parts of the apparatus of FIG.

FIG. 6 is a waveform diagram of signals according to still another embodiment of the ultrasonic diagnostic apparatus of the present invention.

FIG. 7 is an explanatory diagram of the principle of determining the state in which the ultrasonic probe is left in the air in the conventional ultrasonic diagnostic apparatus.

FIG. 8 is a waveform diagram of a signal according to a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 1 Ultrasonic Diagnostic Device 3 Ultrasonic Beamformer 4 Ultrasonic Probe 4c Rubber Lens 10 Waveform Shaping Section 11 Gate Signal Generation Section 12 Pulse Generation Section 13 Pulse Interval Determination Section

Claims (1)

Claim: What is claimed is: 1. An ultrasonic diagnostic apparatus including an ultrasonic probe having an acoustic lens, wherein a reflection detecting unit for detecting reflection of an ultrasonic wave by the acoustic lens and an output of the reflection detecting unit. And a wave transmission control means for controlling the wave transmission of the ultrasonic probe.