JP4664720B2 - Ultrasonic diagnostic apparatus and operation method thereof - Google Patents

Description

  The present invention relates to an ultrasonic diagnostic apparatus that scans the inside of a subject with ultrasonic waves, obtains and displays tomographic images and blood flow velocity information based on the obtained echo signals, and an operation method thereof.

  As a method of discriminating the state where the probe of the ultrasonic diagnostic apparatus is not touching the body and stopping or suppressing transmission to prevent the probe from deteriorating due to heat generation or reflection, reflection by the acoustic lens is an equally-spaced pulse. A method of making an assumption is proposed (Patent Document 1).

According to this method, there is a problem that if there is a reflection signal at equal intervals from the body tissue or phantom, the transmission is stopped during diagnosis because it is mistaken for reflection from the acoustic lens. This imposes a pain on the subject that the examination does not proceed smoothly and the examination time becomes long.
JP-A-5-138

  An object of the present invention is to provide an ultrasonic diagnostic apparatus and an operation method thereof that reliably determine a state in which the probe of the ultrasonic diagnostic apparatus is not touching the body.

An ultrasonic diagnostic apparatus according to an aspect of the present invention transmits an ultrasonic wave having a first frequency and receives an ultrasonic wave, and an image that generates an ultrasonic image based on the ultrasonic wave received by the probe. Generating means; detecting means for detecting an ultrasonic wave having a second frequency lower than the first frequency received by the probe; and controlling transmission of ultrasonic waves by the probe based on a detection result of the detecting means. Transmission control means .

  According to the present invention, since the transmission can be stopped or suppressed by accurately detecting the state of the probe being left in the air, the probe can be prevented from being heated or deteriorated without malfunction during diagnosis.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an ultrasonic diagnostic apparatus according to the first embodiment of the present invention.

  The ultrasonic diagnostic apparatus includes a probe 10, a preamplifier 20, a reception beam former 30, a digital scan converter 40, a CRT 50, a system control CPU 60, and a standing wave detection circuit 70. Furthermore, a transmission circuit 12 and a probe folder 15 are provided.

  In the above configuration, the transmission circuit 12 is. The ultrasonic wave transmitted by the probe 10 is set. The probe 10 transmits and receives ultrasonic waves. The ultrasonic wave received by the probe 10 is converted into an electric signal and amplified by the preamplifier 20. The amplified electrical signal is phased and added by the reception beamformer and detected, converted into a video signal by the digital scan converter 40, and displayed on the CRT 50. When the probe 10 is placed in the normal probe folder 15 when the probe 10 is not used, this is detected, and the transmission / reception of ultrasonic waves from the probe 10 is turned off according to the detection result. The system control CPU 60 controls the entire system.

  On the other hand, a standing wave is detected from the signal from the preamplifier 20 by the standing wave detection circuit 70, and whether or not the probe is in use is determined based on the presence or absence of the standing wave. The standing wave detection circuit 70 includes an LPF 71, a detector 72, and a comparator 73. The LPF 71 removes the high frequency component from the preamplifier 20 and extracts only the standing wave component. The detector 72 performs envelope detection on the signal extracted by the LPF 71. Then, the comparator 73 compares the predetermined value with the detection signal to detect the presence or absence of a standing wave. In the comparator, a value for not detecting noise as a detection signal is selected as the predetermined value. At this time, in order to extract a signal containing many standing waves from an acoustic lens (not shown) of the probe, a signal from the start of transmission to a certain time is cut out. Here, the standing wave in the present invention will be described.

  A determination method using standing waves found by the inventors of the present invention will be described. In the present invention, the presence / absence of a standing wave by the acoustic lens is used to determine whether or not the probe is used. As shown in FIG. 2, the standing wave by the acoustic lens was found to be about 1 MHz when a general acoustic lens had a thickness of about 1 mm and a sound velocity of 1000 m / second. Here, the transmission frequency for imaging with the ultrasonic diagnostic apparatus is about 2 MHz or more. Therefore, since the signal from the tissue consists of the fundamental wave and harmonics of the transmission signal, as shown in FIG. 3, the standing wave by the acoustic lens having a frequency component lower than this can be discriminated by a filter. is there.

  Using such a feature that the frequency component of the standing wave in the acoustic lens is lower than the signal to be imaged and the band is narrow, the non-use state of the probe is detected. When a non-use state of the probe is detected, an operation of reducing the transmission voltage and / or thinning the transmission interval (hereinafter referred to as “monitor mode”) is performed.

  In the monitor mode, when it is detected that the standing wave component due to the acoustic lens has disappeared, the operation of the ultrasonic probe is returned to the state before detection. A signal indicating whether or not the probe 10 is placed on the probe folder 15 is received from the probe 10 to the transmission circuit 12, and generation of ultrasonic waves of the probe 10 is stopped or spaced according to the signal, Control such as reducing the voltage may be performed.

  In the above embodiment, a dedicated circuit (standing wave detection circuit 70) for detecting a standing wave is provided. FIG. 4 is a block diagram illustrating a schematic configuration of the ultrasonic diagnostic apparatus according to the second embodiment. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the signal output from the reception beamformer 30 is input to the digital scan converter 40 and the system control CPU 60. Here, the signal input to the digital scan converter 40 is displayed as an image on the CRT 50, but the signal input to the system control CPU 60 is subjected to frequency analysis by the system control CPU 60 and the frequency of the standing wave by the acoustic lens. The component is extracted and the presence or absence of a standing wave is detected. This result is sent to the transmission circuit 12, and transmission voltage and the like are controlled.

  Note that, similarly to the first embodiment, in this embodiment, in order to extract a signal containing many standing waves by the acoustic lens, a signal from a transmission start to a certain time is cut out and a frequency analysis is performed.

  With reference to FIG. 5, the operation of the ultrasonic diagnostic apparatus according to the above-described embodiment configured as described above will be described.

  When the operation of the ultrasonic diagnostic apparatus starts, it is determined whether or not the probe 10 has been placed in the probe folder 15 (step S1). If the probe 10 is placed in the probe folder 15 (Yes in step S1), the transmission is completely stopped. Here, it can be detected by the following method that the probe 10 is placed in the probe folder 15.

  For example, a reed switch that reacts to magnetism is inserted into the grip portion that enters the folder of the probe 10, and a magnet is provided on the probe folder side. Here, one terminal of the reed switch is connected to GND in the probe, and the other terminal is pulled up to the power source in the apparatus, and a signal is output when the probe 10 is put into the probe folder 15 and when it is output. To reverse. This signal can be used to detect whether the probe 10 has been placed in the probe folder 15. When the probe 10 is removed from the probe folder 15, the monitor mode is restored to prepare for the return to the normal operation.

  If the probe 10 is not placed in the probe folder 15 (No in step S1), it is determined whether or not there is a standing wave by the acoustic lens (step S3), and the monitor mode is entered when the standing wave is detected (step S4). ). If no standing wave is detected in step S3, the normal operation is performed in the monitor mode, and the operation is maintained in the normal operation.

  As described above, when a standing wave is detected, the transmission voltage is decreased to widen the transmission interval and shift to the monitor mode. In this case, the transmission voltage can be lowered to the lowest voltage at which a standing wave can be detected. This voltage is a voltage that does not detect noise by mistake, and is preferably 10 V, for example. Further, with regard to extending the transmission interval, when the user puts the probe on the body of the subject, the transmission interval can be increased to an interval (for example, 0.1 second interval) at which diagnosis can be started without any sense of incongruity.

  Note that the time from when the standing wave is detected until the monitor mode is entered can be set, and can be adjusted according to the user's request, for example. When no standing wave is detected, both the transmission voltage and the transmission interval are set to the normal operation state, and the monitor mode is restored.

  As described above, in this embodiment, the standing wave by the acoustic lens is used to reliably determine a state where the probe of the ultrasonic diagnostic apparatus is not hitting the body, and is transmitted at the time of inspection, and at the time of non-inspection Becomes a monitor mode (that is, a mode in which the transmission voltage is reduced and the transmission interval is thinned out), so that the probe can be prevented from being heated and deteriorated without interrupting the inspection due to a malfunction. In other words, by using the feature that the frequency component of the standing wave in the acoustic lens is lower and narrower than the signal to be imaged, the standing wave in the lens when the probe is left in the air is separated and detected. Reduce the transmission voltage and thin the transmission interval. Then, it is detected that the standing wave component in the lens has disappeared, and transmission is resumed.

  Furthermore, it has a function of detecting that the probe is placed in the probe folder, and when the probe is placed in the probe folder, transmission is completely stopped. After that, when the probe is taken out from the probe folder, the monitor mode is restored.

  According to the embodiment of the present invention, it is assumed that the reflection by the acoustic lens is an equally-spaced pulse and the conventional method for determining the state where the probe of the ultrasonic diagnostic apparatus is not touching the body is determined by the acoustic lens. By using standing waves, it is possible to reliably transmit during inspection and stop transmission during non-inspection, thereby preventing the probe from being heated and deteriorated without interrupting the inspection due to malfunction.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation.
In the above-described embodiment, when the standing wave is detected, the monitor mode is entered. However, the freeze may be automatically entered, and the user may return from the freeze state by releasing the freeze. In this way, although the user needs to perform a release operation, the monitor mode is not used, and transmission can be completely stopped when the probe is not used.
Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  In addition, for example, even if some structural requirements are deleted from all the structural requirements shown in each embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the effect of the invention Can be obtained as an invention.

1 is a block diagram showing a schematic configuration of an ultrasonic diagnostic apparatus according to a first embodiment of the present invention. The figure for demonstrating the standing wave by an acoustic lens. The figure for demonstrating isolation | separation with the transmission frequency for imaging and the standing wave by an acoustic lens. The block diagram which shows schematic structure of the ultrasonic diagnosing device which concerns on 2nd Embodiment. The flowchart which shows operation | movement of the ultrasound diagnosing device which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Probe 12 ... Transmission circuit 15 ... Probe folder 20 ... Preamplifier 30 ... Reception beam former 40 ... Digital scan converter 50 ... CRT
60 ... System control CPU
70 ... standing wave detection circuit 71 ... LPF
72 ... Detector 73 ... Comparator

Claims (7)

A probe that transmits and receives ultrasonic waves of a first frequency;
Image generating means for generating an ultrasound image based on the ultrasound received by the probe;
Detection means for detecting ultrasonic waves of a second frequency lower than the first frequency received by the probe;
An ultrasonic diagnostic apparatus comprising: a transmission control unit that controls transmission of ultrasonic waves by the probe based on a detection result of the detection unit. The ultrasonic diagnostic apparatus according to claim 1,
The transmission control means changes at least one of the transmission voltage from the probe and the transmission interval of the ultrasonic wave based on the detection result of the ultrasonic wave of the second frequency. Ultrasound diagnostic device. The ultrasonic diagnostic apparatus according to claim 1 ,
The transmission control means performs at least one of lowering the transmission voltage from the probe and increasing the transmission interval based on detecting the ultrasonic wave of the second frequency. An ultrasonic diagnostic apparatus characterized by the above. The ultrasonic diagnostic apparatus according to any one of claims 1 to 3,
A probe folder on which the probe can be placed;
The probe folder has a function of detecting placement of the probe,
The transmission control means is configured to transmit at least one of a transmission voltage from the probe and an ultrasonic transmission interval based on the detection result of the placement of the probe in addition to the detection result of the ultrasonic of the second frequency. An ultrasonic diagnostic apparatus characterized by changing one of them. A probe for transmitting and receiving ultrasound,
Detecting means for detecting a standing wave component at a frequency lower than a transmission signal for imaging using the probe;
An ultrasonic diagnostic apparatus comprising: setting means for setting the probe to a monitor mode when the standing wave component is detected. The ultrasonic diagnostic apparatus according to claim 5,
The monitor mode is a mode in which at least one of decreasing the transmission voltage from the probe and increasing the transmission interval is performed.
An ultrasonic diagnostic apparatus characterized by the above. Transmitting ultrasonic waves of a first frequency from a probe;
Generating an ultrasound image based on ultrasound received using the probe;
Controlling the transmission of ultrasonic waves by the probe based on ultrasonic waves received by the probe and having a second frequency lower than the first frequency. Control method of the device.

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