JP2015039593A - Ultrasonic diagnostic device and method of controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate a frequency component which is attenuated by a probe provided with a probe cable.SOLUTION: An ultrasonic diagnostic device 100 includes: a probe 150 provided with a probe cable 110; a display part 130 which displays an ultrasonic image on the basis of an echo signal generated by the probe 150 when the probe 150 receives echo by the ultrasonic wave transmitted from the probe 150 to an inspection object portion; a reference waveform generation part 144 which generates the waveform for wave transmission to the inspection object portion; and a wave transmission waveform generation part 140 which generates a corrected waveform by correcting the waveform generated by the reference waveform generation part 144 in accordance with attenuation characteristics of the probe 150 provided with the probe cable 110, and is characterized so that the waveform corrected by the wave transmission waveform generation part 140 is transmitted to the probe cable 110 of the probe 150 and the probe 150 transmits the ultrasonic wave.

Description

The present invention relates to an ultrasonic diagnostic apparatus.

  Ultrasound diagnostic apparatuses are widely used for examining various parts of the human body, and ultrasonic images of the parts obtained by the ultrasonic diagnostic apparatus provide very important information for diagnosing diseases. In order to find out the symptoms of the disease early, it is essential to improve the quality of ultrasound images. There is a demand for higher image quality of ultrasonic images provided by an ultrasonic diagnostic apparatus.

  In order to improve the image quality of the ultrasonic image, it is desirable to use as high a frequency as possible of the ultrasonic transmission signal transmitted from the probe to the measurement target site and to use an ultrasonic wave having a short wavelength. On the other hand, an ultrasonic wave having a high frequency has a large attenuation rate during propagation. When an ultrasonic transmission signal with a high frequency is used to obtain an image of a part located deep inside the body, the ultrasonic transmission signal is greatly attenuated before reaching the measurement target part, and further from the measurement target part. Is greatly attenuated until it reaches the probe. For this reason, the echo obtained from the measurement target part, that is, the signal of the reflected wave becomes very small. In spite of increasing the frequency of the ultrasonic transmission signal in order to improve the image quality of the ultrasonic image, the image quality of the obtained ultrasonic image is lowered when the measurement target part is deep.

  On the other hand, when the measurement target site is in the vicinity of the body surface such as the mammary gland or the thyroid gland, the image quality can be improved by setting the ultrasonic transmission signal to a high frequency. As described above, in the ultrasonic diagnostic apparatus, it is desirable to change the frequency of the ultrasonic transmission signal to be used in a wide range depending on whether the position of the part to be imaged is a deep body position or the vicinity of the body surface. The ultrasonic diagnostic apparatus generates an electric signal for generating an ultrasonic waveform to be transmitted as an ultrasonic transmission signal by a transmission waveform generation unit, transmits the generated electric signal to the probe, and An ultrasonic transmission signal having a waveform based on the electrical signal is transmitted to the measurement target region.

  As described above, it is desirable to appropriately select the frequency of the ultrasonic transmission signal according to the measurement target, and the frequency of the ultrasonic transmission signal used tends to be wider. For this reason, for example, Patent Document 1 proposes a probe for use at a high frequency.

JP 2008-118168 A

  From the viewpoint of obtaining sufficient image quality even if the frequency of the ultrasonic transmission signal is changed over a wide range, it is still not perfect. Furthermore, it is desired to improve the quality of ultrasonic images. There have been various proposals to improve the performance of a probe. However, it is desired to study the improvement of performance not only from the probe but also from the whole ultrasonic diagnostic apparatus.

  An object of the present invention is to provide an ultrasonic diagnostic apparatus in which the image quality of an ultrasonic image is further improved.

  The ultrasonic diagnostic apparatus according to the present invention includes a probe having a probe cable, and the probe receives an echo by an ultrasonic wave transmitted from the probe to a site to be inspected, and the probe A wave receiving and phasing unit for processing the generated echo signal, a display unit for displaying an ultrasonic image based on the echo signal, and a reference for generating a waveform to be transmitted to the examination site A waveform generation unit, and a transmission waveform generation unit that generates a corrected waveform by correcting the waveform generated by the reference waveform generation unit according to the attenuation characteristics of the probe having the probe cable, The waveform corrected by the transmission waveform generation unit is sent to the probe cable of the probe, and the probe transmits the ultrasonic wave.

  ADVANTAGE OF THE INVENTION According to this invention, the ultrasonic diagnosing device which the image quality of the ultrasonic image improved more can be obtained.

1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus 100 that is an embodiment of the present invention. It is explanatory drawing explaining the structure of a probe. It is a graph which shows the attenuation characteristic with respect to the frequency component of a waveform which the probe provided with the probe cable has. It is a block diagram which shows the structure of a transmission waveform production | generation part. It is explanatory drawing explaining the peaking circuit which is a specific example of a characteristic circuit. It is a characteristic view explaining the characteristic of a peaking circuit. It is a graph which shows a reference waveform. It is a graph explaining the distortion of the waveform by a probe. It is a graph explaining the result of correction | amendment by a characteristic circuit. 10 is a graph for explaining a waveform of an ultrasonic wave output from the probe when the corrected waveform shown in FIG. 9 is applied to the probe cable. It is a circuit diagram which shows one Example of a transmission waveform production | generation part. It is explanatory drawing explaining the output waveform of the output terminal of a transmission circuit. It is a block diagram explaining operation | movement of a waveform comparison calculating part. It is a flowchart explaining the operation | movement of the block diagram described in FIG. It is explanatory drawing explaining the database memorize | stored in memory. It is a flowchart explaining the setting operation | movement of a reference waveform. It is a flowchart which calculates | requires the control data of a selection circuit. It is a flowchart explaining the alternative which produces | generates the reference | standard waveform by which the transmission waveform production | generation part was correct | amended. It is explanatory drawing explaining the database used with the alternative of FIG.

  In the drawings for explaining the embodiments of the present invention, the same reference numerals are assigned to the steps of performing substantially the same configuration or substantially the same processing. The description of the same reference numerals and steps may not be repeated.

[1. Overall configuration of ultrasonic diagnostic apparatus 100]
FIG. 1 is a block diagram showing a configuration of an ultrasonic diagnostic apparatus 100 according to an embodiment of the present invention. The memory 250 stores various waveform data as a database according to the region to be examined, the frequency of ultrasonic waves to be transmitted, the number of sampling points, the amount of delay, and the like. In order to generate an ultrasonic transmission signal to be transmitted toward an inspection object, first, a database is searched according to transmission conditions such as a probe to be used and a transmission frequency, and an optimum beam waveform is determined. The ultrasonic waveform data retrieved from the memory 250 and the delay amount are sent to the transmission phasing unit 144.

  The transmission wave phasing unit 144 generates a digital signal having a reference waveform representing an ultrasonic waveform from the waveform data read from the memory 250, and converts the digital signal into an analog signal by the DA converter 142. The signal converted into the analog signal by the DA converter 142 is sent to the transmission waveform generation unit 140 and further passed through the probe cable 110 that connects the ultrasonic diagnostic apparatus main body 102 of the ultrasonic diagnostic apparatus 100 and the probe 150. The probe 150 is sent to the probe 150, and an ultrasonic signal is transmitted from the probe 150 toward the inspection target region. The wave transmission phasing unit 144 operates as a reference waveform generation unit that generates a reference waveform transmitted toward the examination target site according to the examination target site.

  The probe 150 receives an echo based on the ultrasonic signal transmitted toward the inspection target site, and generates an ultrasonic reception signal. The ultrasonic reception signal is sent to the transmission / reception separation circuit 116 via the probe cable 110, sent to the AD converter 122 from the transmission / reception separation circuit 116 through the transmission / reception separation circuit 116, and converted into a digital signal. The digital signal is subjected to phasing processing by the wave receiving phasing unit 124, signal processing is performed by the signal processing unit 126, and the signal-processed signal passes through the DSC unit 128, and then an ultrasonic image is displayed on the display unit 130. .

  Note that the control of each unit is performed by the control unit 300 in accordance with an operation by the operator. The control unit 300 performs each flowchart described below, searches a database stored in the memory 250 described below, and various calculation processes performed by the transmission waveform generation unit 140. Of course, this is only an example. For example, the transmission phasing unit 144 and the transmission waveform generation unit 140 may have a function of searching a database stored in the memory 250. Further, the transmission waveform generation unit 140 may have a function of performing various arithmetic processes. However, by intensively processing such processing in the control unit 300, it becomes easy to create and manage each application program, leading to improvement in the reliability of the ultrasonic diagnostic apparatus 100.

[2. Structure of probe 150]
FIG. 2 is a conceptual diagram showing an example of the probe 150. The piezoelectric material 156 converts the analog electrical signal sent from the probe cable 110 into mechanical vibration, and ultrasonic waves are generated. The generated ultrasonic wave is transmitted from the acoustic lens 152 via the acoustic matching layer 154. The acoustic lens 152 functions to prevent the ultrasonic wave output from the probe 150 from spreading and converge. This improves the resolution.

  The ultrasonic echo vibrates the piezoelectric material 156 through the acoustic lens 152 and the acoustic matching layer 154, and the piezoelectric material 156 generates an ultrasonic reception signal that is an electrical signal of mechanical vibration.

[3. Characteristics of probe cable 110 and probe 150]
The probe 150 has a structure that is devised in various ways so as to improve the inspection accuracy corresponding to the inspection region. However, as a basic characteristic, as the frequency of the analog signal transmitted from the transmission waveform generation unit 140 to the probe 150 increases, the analog electric signal generated by the transmission waveform generation unit 140 is output from the probe 150. The distortion of the ultrasonic waveform is increased. That is, the attenuation tends to increase as the frequency of the analog signal increases.

FIG. 3 is a diagram showing an example of the attenuation amount before and after passing through the probe lens and the cable in the signal of each frequency. An example of the frequency characteristic of the signal after passing through the acoustic lens 152 of the probe 150 and the probe cable 110 is shown by a graph B which is a solid line. The analog electrical signal generated by the transmission waveform generation unit 140 has many frequency components as described in the graph A, for example. Each frequency component of the graph A is not attenuated uniformly, but the amount of attenuation increases as the frequency component increases. The attenuation amount can be generally expressed by the following formula (Equation 1).
Attenuation [dB] = Attenuation coefficient [dB / cm · MHz] × Frequency [MHz] × Passing distance [cm] (Equation 1)

  As shown in (Expression 1), the amount of attenuation increases as the frequency increases. For example, assuming that the state of the frequency component shown in the graph A is the frequency component of the analog electrical signal generated by the transmission waveform generation unit 140, the graph B is the frequency component of the ultrasonic signal output by the probe 150. Assume that there is. For example, paying attention to the frequency component being a 5.0 MHz component and the frequency component being a 6.5 MHz component, the state of attenuation in the graph B with respect to the graph A is seen. It can be seen that the attenuation of the 6.5 MHz component is much larger than the attenuation amount of the 6.5 MHz component, and the frequency component of 6.5 MHz is attenuated by about 20 dB.

  Thus, it can be seen that the frequency characteristic of the transmission signal output from the probe 150 has less high-frequency components than the desired frequency characteristic. Even if a transmission signal having a frequency characteristic optimal for the inspection target part is sent from the transmission waveform generation unit 140 to the probe 150 via the probe cable 110, the probe 150 generates and directs the transmission signal toward the inspection target part. The frequency component of the ultrasonic waveform transmitted in this manner is far from the optimum frequency characteristic. This is a factor that degrades the image quality of the ultrasonic image of the ultrasonic diagnostic apparatus 100.

[4. Improvement of frequency characteristics of ultrasonic diagnostic apparatus 100]
It seems that research has been conducted to cope with the above-mentioned problems by improving the frequency characteristics of the probe cable 110 and the probe 150, but sufficient results cannot be obtained by itself. Therefore, in this embodiment, the transmission waveform generation unit 140 generates a transmission signal in consideration of the characteristics of the probe cable 110 and the probe 150. An example of this generation circuit is shown in FIG. FIG. 4 is a block diagram illustrating a configuration for one channel of the transmission waveform generation unit 140 according to an embodiment of the present invention. The transmission waveform generation unit 140 may have not only one channel but also a plurality of channels. In this case, it is possible to cope with this by providing a plurality of one channel shown in FIG. 4 in parallel.

  The transmission signal analog-converted by the DA converter 142 branches to a characteristic circuit constituting the characteristic correction circuit 200 selected by the control unit 300 by the selection circuit 220. Not only one characteristic circuit but also a plurality of characteristic circuits may be branched depending on circumstances, and synthesized by the synthesis circuit 230 and sent to the amplifier circuit 240. The characteristic correction circuit 200 includes a plurality of characteristic circuits 202, 204, and 206 each having different frequency characteristics. The control unit 300 controls the selection circuit 220 to output one or more of the plurality of characteristic circuits 202, 204, and 206 so that a transmission signal having an appropriate characteristic is output from the transmission waveform generation unit 140. The transmission signal is selected or supplied to the selected characteristic circuit or supplied to a plurality of characteristic circuits. The output of each characteristic circuit is synthesized by the synthesis circuit 230, and the synthesized signal is amplified by the amplifier circuit 240 and sent to the probe cable 110.

  In this way, the transmission signal is corrected by the transmission waveform generation unit 140, whereby a transmission signal in which the peak value of the high frequency component is corrected to be larger than necessary with respect to the optimum state is supplied to the probe cable 110. . Thus, even if the high-frequency component is attenuated greatly by the probe cable 110 or the probe 150 by supplying the probe signal 110 with the transmission signal in which the peak value of the high-frequency component is corrected more than necessary. Then, an ultrasonic signal having an optimum characteristic is output from the probe 150 and transmitted to a region to be inspected. By doing in this way, the image quality of the ultrasonic image which the ultrasonic diagnostic apparatus 100 produces | generates can be improved.

  There are various types of the probe 150 including the probe cable 110, and the probe 150 is selected according to the region to be inspected. The probe 150 including the probe cable 110 has various characteristics depending on the type and the product. Moreover, the frequency of the ultrasonic wave used differs with a region to be examined. A high frequency is used for a portion that is close to the body surface, such as a mammary gland and a thyroid gland. Even if the same probe 150 is provided with the same probe cable 110, the amount of attenuation differs if the frequency used is different. Therefore, the control unit 300 controls the selection circuit 220 according to the type of the inspection target region and the same probe 150 including the probe cable 110, and the like, and the same probe including the inspection target region and the probe cable 110 is controlled. Correction according to the type of the touch element 150 is performed.

[4.1 Description of Characteristic Correction Circuit 200]
Each characteristic circuit 202, 204, or 206 included in the characteristic correction circuit 200 is made of, for example, a peaking circuit having a different characteristic. FIG. 5 shows an embodiment in which the characteristic circuit 202 is configured by using a peaking circuit by taking the characteristic circuit 202 as an example of the characteristic circuit. A coil 256 and a capacitor 258 are connected in series between the input terminal 252 and the output terminal 254, and a voltage dividing point between the resistor 262 and the resistor 264 is connected to the output terminal 254. The values of the circuit elements shown in FIG. 5 are selected so as to obtain the characteristics shown in FIG. 6 with this peaking circuit. For example, by selecting the values of the coil 256 and the capacitor 258 so that the resonance frequency of the coil 256 and the capacitor 258 becomes 6.5 MHz, the attenuation at 6.5 MHz can be made zero. That is, at 6.5 MHz, the impedance of the series circuit of the coil 256 and the capacitor 258 is theoretically zero, and the state is the same as when the input terminal 252 and the output terminal 254 are short-circuited. When the frequency is very low or very high, the impedance of the series circuit of the coil 256 and the capacitor 258 is almost infinite, and the attenuation is determined by the voltage division ratio of the resistor 262 and the resistor 264. The frequency range lower than the resonance frequency and the higher frequency range are determined by the relationship between the coil 256 and the capacitor 258. In particular, the impedance of the capacitor 258 increases in the frequency range lower than the resonance frequency, and therefore greatly depends on the capacitance of the capacitor 258. It becomes a characteristic. On the other hand, in the frequency region higher than the resonance frequency, the impedance of the coil 256 becomes large, so that the characteristic is determined largely depending on the value of the coil 256. In this way, by selecting the values of the coil 256, the capacitor 258, the 262, and the resistor 264, desired characteristics can be set, and the characteristics shown in FIG. 6 can be obtained.

[4.2 Explanation of Correction Operation of Characteristic Correction Circuit 200]
As described above, a preferable waveform of the ultrasonic wave transmitted from the probe 150 to the inspection target region of the subject 10 is read from the database of the memory 250 based on the inspection target region and the like, and an analog signal 170 having a preferable waveform is obtained. Output from the DA converter 142. An example of this preferred waveform analog signal 170 is shown in FIG. In this example, a waveform having a frequency bandwidth up to around 6.5 MHz at a center frequency of 5.0 MHz is shown, and the amplitude is slightly smaller in the vicinity of 6.5 MHz with respect to the center frequency of 5.0 MHz. When the analog signal 170 having a preferable waveform is output directly from the amplifier circuit 240 to the probe cable 110 without passing through the characteristic correction circuit 200, the probe cable 110 and the probe 150 are described with reference to FIG. The ultrasonic wave having the characteristic and having the waveform shown by the graph 162 in FIG. 8 is output from the probe 150.

  That is, as described with reference to FIG. 3, the probe cable 110 and the probe 150 pass through the probe lens and the cable, and the 6.5 MHz band is attenuated by about 20 dB with respect to 5.0 MHz. Therefore, in FIG. 8, the analog signal 170 having a preferable waveform sent to the probe cable 110 has a waveform shown by a graph 162. As a result, the high-frequency component near 6.5 MHz is attenuated as compared with the analog signal 170 having a preferable waveform, which is significantly different from the frequency characteristic of the analog signal 170 having a preferable waveform.

  In the embodiment shown in FIG. 4, an ultrasonic signal having a preferable waveform can be output from the probe 150 by correcting the analog signal 170 having a preferable waveform with the characteristic circuit shown in FIG. 5. In the circuit shown in FIG. 4, when an analog signal 170 having a preferable waveform is input to the characteristic circuit 202 having the characteristics shown in FIG. 6 via the selection circuit 220, the graph shown by the solid line in FIG. A signal 172 having a waveform composed of frequency components indicated by In the graph 172 indicated by the solid line, the amplitude of 6.5 MHz is larger than the amplitude of 5.0 MHz.

  The frequency characteristic shown in FIG. 6 possessed by the characteristic circuit 202 shown in FIG. 5 is characterized in that 6.5 MHz is a peak frequency and the vicinity of 5 MHz is attenuated by about 10 dB. As described with reference to FIG. 3, this characteristic is set so as to correspond to the frequency characteristic in which the signal is attenuated by passing through the probe cable 110 and the acoustic lens 152. Therefore, a signal having a desired frequency characteristic is input to the input terminal 252 of the characteristic circuit 202 having the frequency characteristic shown in FIG. 6, and each frequency received by the characteristic circuit 202 by passing through the probe cable 110 and the acoustic lens 152. Make corrections to compensate for component attenuation in advance. As a result, the output characteristic of the ultrasonic signal output from the probe 150 is the characteristic of the graph 162 indicated by the solid line in FIG.

  The characteristic indicated by the solid line graph 162 in FIG. 10 is very close to the characteristic indicated by the analog signal 170 having a preferable waveform in FIG. 7, which leads to an improvement in inspection accuracy. In this way, the inspection that greatly contributes to the improvement of the inspection accuracy is particularly an inspection near the body surface. The examination site is the thyroid gland and mammary gland. Here, while the 6.5 MHz frequency is attenuated by 20 dB, the correction amount of the 6.5 MHz frequency by the characteristic circuit 202 is 10 dB as shown in FIG. This is because if the value of the circuit element is set such that the frequency correction amount is about 20 dB, the characteristic circuit 202 configured by the peaking circuit may oscillate.

  In practice, since a signal having a waveform that swings from positive polarity to negative polarity is input to the transmission waveform generation unit 140, a transmission circuit 210 is provided on the input side of the circuit of FIG. A transmission waveform generation unit 140 provided with the transmission circuit 210 is shown in FIG. The transmission circuit 210 includes a PMOSFET connected to a positive power source and an NMOSFET connected to a negative power source. When a negative signal is input from the DA converter 142, the PMOSFET becomes conductive, and the connection point A is a positive power source. Connected to. On the other hand, when a positive signal is input from the DA converter 142, the NMOSFET becomes conductive, and the connection point A is connected to the negative power source. Therefore, if the transmission circuit 210 is driven with one pulse having bipolar polarity, the waveform shown in FIG. 12 is ideally generated at the connection point A between the PMOSFET and the NMOSFET.

  However, since a load is actually connected to the connection point A, the waveform deteriorates. In addition, the circuit between the gate and source of each MOSFET described in FIG. 11 is an explanatory diagram for explaining the concept, and a specific circuit is omitted.

[4.3 Description of Other Examples]
FIG. 13 shows another embodiment for calibrating the characteristics of the probe cable 110 and the probe 150 as described above. This embodiment has a function of detecting and calibrating the characteristics of the probe cable 110 and the probe 150 on the main body side of the ultrasonic diagnostic apparatus 100. In order to simplify the explanation, in this embodiment, the transmission waveform generation unit 140 transmits one channel. When it is necessary to increase the number of channels as well as one, it is possible to increase the number of channels by providing a plurality of similar circuits as necessary.

  In the present embodiment, a calibration mode for calibrating the characteristics of the probe cable 110 and the probe 150 is executed before transmitting the actual ultrasonic wave toward the inspection target part. In the calibration mode, the transmission phasing unit 144 generates a reference waveform and detects the frequency characteristic of the probe cable 110 and the frequency characteristic of the probe 150 in order to detect the analog signal of the probe cable 110. Send to. This reference waveform is determined in accordance with the target site for the subsequent inspection or the probe 150 used for the inspection. For example, it can be obtained by searching a database provided in the memory 250 based on the inspection target part or the probe 150. The reference waveform has a frequency characteristic corresponding to a transmission wave of an ultrasonic wave corresponding to a part to be inspected or adapted to the probe 150 used for the inspection.

  The reference waveform generated by the transmission phasing unit 144 operating as the standard waveform generation unit is converted to an analog signal by the DA converter 142 and sent to the probe cable 110. In the calibration mode in which the calibration process is performed, the characteristic correction circuit 200 transmits the converted analog signal to the probe cable 110 as it is without being corrected or simply amplified. For this purpose, the characteristic correction circuit 200 includes a non-correction circuit 208. In the calibration mode, the control unit 300 selects the uncorrected circuit 208 that is not corrected, and the reference waveform converted into the analog signal is amplified by the transmission amplifier circuit 240 via the uncorrected circuit 208. The signal is output from the main body of the ultrasonic diagnostic apparatus 100 to the probe cable 110.

  The reference waveform converted into the analog signal is sent to the probe 150 through the cable 112 used at the time of inspection of the probe cable 110. Inside the probe 150 is a switch 312 that is conductive only in the calibration mode, reflected by the acoustic lens 152 of the ultrasonic probe, and attenuated transmitted signal after passing through the cable 114 of the probe cable 110. Is fed back to the main body of the ultrasonic diagnostic apparatus 100.

  The signal fed back via the switch 312 passes through the attenuator 324 and is input to the LNA unit 330. In the calibration mode, the switch 332 is connected to the attenuator 324 side. Therefore, the output of the attenuator 324 passes through the LNA unit 330 and is input to the DA converter 336. The signal is converted into a digital signal by the DA converter 336 and stored in the waveform comparison calculation unit 350 including the waveform memory 352 therein.

  A reference waveform represented by a digital signal generated by the transmission phasing unit 144 is input to the waveform comparison calculation unit 350. The input reference waveform and the waveform stored in the waveform memory 352 are compared. Based on the comparison result, the waveform comparison calculation unit 350 calculates and determines which frequency component is attenuated with respect to the reference waveform when the analog signal of the reference waveform passes through the cable 112 of the probe cable 110. be able to. In order to make the transmission signal of the output of the probe 150 close to the desired transmission signal, which characteristic circuit of the characteristic circuit 206 should be selected from the characteristic circuit 202, that is, the control content of the selection circuit 220, Can be calculated The control content of the selection circuit 220 obtained by the calculation is sent from the waveform comparison calculation unit 350 to the control unit 300 and used for the control during the inspection.

  First, the control content of the selection circuit 220 for correcting the frequency characteristics of the probe 150 including the probe cable 110 to be used is detected in the calibration mode, and then actual ultrasonic wave transmission is started. The inspection target part is inspected.

  The comparison operation between the reference waveform and the signal obtained from the probe 150 by the waveform comparison calculation unit 350 may be performed in the state of the waveform signal as described above, or each waveform to be compared is converted into a frequency distribution. They may be converted and compared with each other.

  The probe is switched to a suitable shape depending on the region to be inspected, and the frequency of the ultrasonic wave used is also switched. For this reason, the attenuation characteristic of the probe 150 provided with the probe cable 110 changes each time. In the embodiment described with reference to FIG. 13, the characteristic of the probe 150 used before the start of inspection can be detected, and the calibration method can be obtained by calculation. Therefore, the effect is very large. The calibration mode is started by, for example, providing an input means for starting calibration, such as an operation button, in the operation unit of the ultrasonic apparatus, and the operation described with reference to FIG. 13 is started when the operator operates the operation button. You may be made to do.

  When the calibration mode ends and the test state is entered, the switch 312 is released, and the switch 332 is connected to the transmission / reception separating circuit 116. The wave phasing unit 144 generates a reference waveform from the waveform data obtained based on the search result of the memory 250, and the generated reference waveform is sent from the wave phasing unit 144 to the DA converter 142. The reference waveform is converted into an analog signal by the DA converter 142. Based on the control content detected in the previous calibration mode, the control unit 300 controls the selection circuit 220, and the reference waveform signal converted to the analog signal is the selected characteristic circuit as described with reference to FIG. And is guided to the probe 150 through the amplifier 112 through the cable 112 of the probe cable 110. Although attenuation according to the frequency component occurs in the cable 112 of the probe cable 110, the characteristic correction circuit 200 corrects the waveform as a result of attenuation as described with reference to FIG. The ultrasonic wave having a desired waveform is output from the probe 150.

  The echo from the inspection target site is received by the probe 150 and converted into an echo signal, and the echo signal is guided from the probe cable 110 to the transmission / reception separating circuit 116. As described with reference to FIG. 1, the echo signal is guided from the transmission / reception separating circuit 116 to the LNA unit 330 via the switch 332, converted into a digital signal by the DA converter 336, and sent to the wave receiving and phasing unit 124. As described in 1, an ultrasonic image is generated and displayed on the display unit 130.

[4.4 Explanation of operation in calibration mode]
Although the operation in the calibration mode has been described with reference to FIG. 13, the operation sequence will be described with reference to the flowchart of FIG. When an input of a part for inspection, an input of the probe 150 to be used, an input of an ultrasonic frequency, or the like is performed, execution of the calibration mode starting at step S100 is started. In step S101, it is determined whether or not there is an instruction to perform calibration by the operator. If there is no instruction to perform calibration, execution proceeds from step S112 to step S200, and a detection mode in which inspection is executed is set.

  When there is an instruction to perform calibration, step S114 is executed after step S112. When the operator gives an instruction in step S114, for example, when the operator presses a button for inputting a calibration instruction, the analog standard waveform described in FIG. 13 is sent to the probe cable 110 based on this instruction. It is done. Further, it is fed back to the main body of the ultrasonic diagnostic apparatus 100 via the cable 114 of the probe cable 110 and stored in the waveform memory 352 of the waveform comparison calculation unit 350. In step S116, the attenuation amount of the probe cable 110 and the probe 150 is calculated by the waveform comparison calculation unit 350, and in step S118, control details for operating the characteristic correction circuit 200 are obtained. That is, control data for selecting which characteristic circuit is sent from the waveform comparison calculation unit 350 to the control unit 300 and used for control during inspection.

  In step S120, the calibration process is terminated, and the execution shifts to step S200 to enter an inspection mode in which an inspection can be started. When the operator decides to perform calibration during the inspection, the calibration mode shown in FIG. 14 is executed by operating an operation for instructing calibration, for example, an input button.

  In FIG. 13, step S <b> 114 may not be provided, but it is desirable to provide step S <b> 114 in order to match the timing of the preparation performed by the operator and the processing of the ultrasonic diagnostic apparatus 100. For example, there is a possibility that inconveniences such as troublesome installation of the probe 150 or other execution of step S116 while the operator is still preparing may cause an error. In step S114, the operator presses the calibration instruction button. However, the transmission characteristics change when the probe is selected or when the probe frequency range is selected. It is also possible to proceed to the next step on the assumption that step S114 is automatically executed at the time of the operation in which occurrence occurs.

  In the process of selecting the peaking circuit as the characteristic circuit in step S118, the ultrasonic power output from the probe 150 is added in consideration of a limit value that does not exceed safe power.

[5. Description of database in memory 250]
FIG. 15 shows a database 402 provided in the memory 250 in which reference waveform data is stored. When a search target part is input as a search word and searched, optimum frequency and waveform data relating to the test target part are read out. When searching using the frequency as a search word, the data of the optimum waveform is read out. In addition, when the number of samplings and the amount of delay are used as search words, data having an optimum waveform is read out.

  Setting of a standard waveform using the database 402 will be described with reference to a flowchart shown in FIG. When the generation of the reference waveform in the transmission phasing unit 144 in FIG. 1 and the generation of the reference waveform in the transmission phasing unit 144 in FIG. 13 are started, the flowchart shown in step S140 in FIG. 16 is started. In step S142, a part to be examined is input or data of a part to be examined that has already been input is read. In step S144, the optimum frequency and reference waveform are read and displayed using the region to be examined as a search word. Further, the sampling number and the delay amount may be displayed.

  The operator performs an operation indicating consent “Y” when performing the inspection with the displayed contents, and performs an operation indicating “N” when not performing the inspection. If an operation indicating NO is performed and the operator inputs new data in step S148, a search based on the new input data is performed on the database 402 shown in FIG. 15 in step S148. A new reference waveform is read out.

  The waveform data read out by searching the database 402 in step S144 or step S148 is set in the transmission phasing unit 144, and 144 generates a transmission waveform based on the set data via the DA converter 142. To the unit 140. The search by the search word in the database 402 may be performed by the transmission wave phasing unit 144, but may be performed by the control unit 300 instead of the transmission wave phasing unit 144.

  The calibration process shown in FIG. 14 and the calibration operation shown in FIG. 17 are performed based on the operation of the operator. For example, as indicated by a broken line in FIG. 15, when the operator determines that calibration processing is necessary, a calibration instruction is given to the input unit of the ultrasonic diagnostic apparatus 100. As soon as calibration is instructed, the flowchart of FIG. 14 starts.

  The control of the selection circuit 220 in FIG. 4 is also the same. When the operator determines that the calibration process is necessary, the flowchart shown in step S180 is operated, and the execution proceeds from step S182 to step S184. In step S184, the control unit 300 reads the database based on the frequency used for the inspection that has already been set and the word identifying the probe 150 such as the product name or model of the probe 150 used for the inspection. Which characteristic circuit among the characteristic circuit 202, the characteristic circuit 204, and the characteristic circuit 206 included in the correction circuit 200 is to be used is determined. Although not shown, characteristic circuit selection data for optimal correction is stored in advance using the frequency used for the inspection and the type of the probe 150 used for the inspection as a search word, and the frequency used and the inspection are stored. The optimum characteristic circuit can be selected using the type of the probe 150 to be used as a search word. In this embodiment, the characteristic correction circuit 200 has only three characteristic circuits for the sake of simplicity. However, an actual product can have many characteristic circuits, and optimal correction can be performed. it can.

  In step S184, an optimum characteristic circuit is searched, and the result is set in the control unit 300. For example, in the control of the selection circuit 220 illustrated in FIG. 4, the control unit 300 can select the set characteristic circuit by controlling the selection circuit 220.

[6. Description of another embodiment for correction using characteristic correction circuit 200]
4, 11, and 13, the characteristic correction circuit 200 including a plurality of characteristic circuits is used as an example in order to correct the attenuation characteristics of the probe 150 including the probe cable 110. It was. 18 and 19, the above correction is performed by processing using software instead of the characteristic correction circuit 200. When step S250 is started, the reference waveform is determined by the method described in FIG. 16, for example. The type of the probe 150 used for the inspection can be detected by connecting the probe 150 to the ultrasonic diagnostic apparatus 100 or by an input operation of the operator. The corrected waveform described with reference to FIG. 9 is stored as the database 404 in advance using the reference waveform and the type of the probe 150 as search words. In step S256, the database 404 is searched, and a waveform having a characteristic corrected by the characteristic correction circuit 200 described with reference to FIG. Waveform data acquired based on the database 404 is set in the transmission phasing unit 144.

  Thus, a corrected waveform for calibrating the attenuation of the probe 150 generated by the transmission waveform generation unit 140 is generated by the transmission phasing unit 144, and the probe cable 110 is generated. Send to. By doing so, an output similar to that of the characteristic correction circuit 200 can be obtained without using the characteristic correction circuit 200.

[7. Effect of the above-described embodiment]
The effects of the above-described embodiment have already been described, but will be further described below.

  By adjusting the frequency characteristics through the transmission signal to a peaking circuit as a characteristic circuit having a peak at an arbitrary frequency, a transmission waveform in consideration of the attenuation in the acoustic lens 152 or the probe cable 110 after output from the ultrasonic device is obtained. Can be generated.

  In the above embodiment, one characteristic circuit is selected by the selection circuit 220 to simplify the description. However, in this embodiment, a synthesis circuit 230 capable of synthesizing a plurality of outputs of the characteristic circuit is provided. . Accordingly, it is possible to select a plurality of characteristic circuits by the selection circuit 220, branch to the plurality of characteristic circuits, and apply the reference signal. By splitting the reference signal into a plurality of characteristic circuits, each having a different frequency characteristic, a transmission waveform having various frequency characteristics can be generated by adding the output signals. For this reason, various corrections are possible, and an optimum transmission waveform can be output for each probe. Since an optimal transmission waveform can be generated for the site to be diagnosed, image quality can be improved.

  It has a transmission waveform calibration function that compensates the attenuation and controls the generation of the optimal transmission waveform for the connection probe of the ultrasonic device, and the operator of the ultrasonic device presses a button on the device. By this instruction, the transmission waveform calibration can be automatically started. Therefore, even when the connection probe is changed, the optimum transmission signal calibration can be easily realized.

  Since the frequency characteristics of the transmission signal actually output from the probe can be fed back and calibrated, an unnecessary high-frequency component can be obtained by combining the transmission waveform generation in the characteristic correction circuit 200 and the transmission phasing unit 144. Can be reduced. Thereby, the heat loss in the probe lens can be reduced, and the temperature rise of the probe lens can be suppressed.

  DESCRIPTION OF SYMBOLS 100 ... Ultrasonic diagnostic apparatus, 102 ... Ultrasonic diagnostic apparatus main body, 110 ... Probe cable, 112 ... Cable, 114 ... Cable, 116 ... Transmission / reception separation circuit, 122. .. AD converter 124... Received wave phasing section 126... Signal processing section 130... Display section 140... Transmission waveform generating section 150. ..Characteristic correction circuit 202 ... Characteristic circuit 204 ... Characteristic circuit 206 ... Characteristic circuit 208 ... No correction circuit

Claims (10)

A probe having a probe cable;
A wave phasing unit and a signal processing unit that receive an echo from an ultrasonic wave transmitted from the probe to a site to be inspected and process an echo signal generated by the probe; and
A display unit for displaying an ultrasonic image based on the echo signal;
A reference waveform generation unit that generates a waveform to be transmitted to the examination site;
A transmission waveform generation unit that generates a corrected waveform by correcting the waveform generated by the reference waveform generation unit according to the attenuation characteristics of the probe having the probe cable;
The ultrasonic diagnostic apparatus, wherein the waveform corrected by the transmission waveform generation unit is sent to the probe cable of the probe, and the probe transmits the ultrasonic wave.   The ultrasonic diagnostic apparatus according to claim 1, further comprising a memory storing a database, wherein the reference waveform generation unit generates the waveform from a search result using at least a region to be examined as a search word. An ultrasonic diagnostic apparatus characterized by the above. The ultrasonic diagnostic apparatus according to claim 1,
The transmission waveform generation unit has a plurality of characteristic circuits that output with varying amplitudes with respect to frequency components of the input waveform, and each of the plurality of characteristic circuits has a frequency component of the output waveform with respect to the frequency components of the input waveform. Has different characteristics of the amplitude change,
The ultrasonic diagnostic apparatus, wherein the characteristic circuit is selected according to an attenuation characteristic of the probe having the probe cable, and the corrected waveform is generated by the selected characteristic circuit.   The ultrasonic diagnostic apparatus according to claim 3, wherein the plurality of characteristic circuits are configured by peaking circuits. The ultrasonic diagnostic apparatus according to claim 1,
A waveform comparison calculation unit is further provided,
The waveform comparison operation unit compares an input waveform input to the probe cable of the probe having the probe cable and an attenuation waveform after passing through the probe cable,
The ultrasonic diagnostic apparatus, wherein the transmission waveform generation unit corrects the waveform generated by the reference waveform generation unit based on a comparison result of the waveform comparison calculation unit. The ultrasonic diagnostic apparatus according to claim 3.
A waveform comparison calculation unit is further provided,
The waveform comparison operation unit compares an input waveform input to the probe cable of the probe having the probe cable and an attenuation waveform after passing through the probe cable,
The ultrasonic diagnostic apparatus, wherein the transmission waveform generation unit selects a preferable characteristic circuit from the plurality of characteristic circuits based on a comparison result of the waveform comparison calculation unit.   6. The ultrasonic diagnostic apparatus according to claim 5, wherein a comparison operation between an input waveform input to the probe cable by the waveform comparison calculation unit and an attenuated waveform after passing through the probe cable is a calibration. An ultrasonic diagnostic apparatus, wherein the calibration mode is performed in a mode and the calibration mode is started in accordance with an instruction from an operator. The ultrasonic diagnostic apparatus according to claim 5,
The probe cable of the probe includes a first cable for sending an analog waveform to the probe, and a second cable for returning the analog waveform attenuated by the first cable, the second cable The ultrasonic diagnostic apparatus, wherein the attenuated analog waveform returned via a cable is digitally converted and sent to the waveform comparison calculation unit as the attenuated waveform. The ultrasonic diagnostic apparatus according to claim 1,
The ultrasonic diagnostic apparatus according to claim 1, wherein the waveform generated by the reference waveform generation unit is corrected by the transmission waveform generation unit when the examination target site is a mammary gland or a thyroid gland. A first step of transmitting an ultrasonic wave from a probe having a probe cable to a region to be inspected, the echo being received by the probe and generating an echo signal;
A second step of displaying an ultrasound image based on the echo signal on the display unit; a third step of generating a reference waveform for transmitting to the examination target site;
A fourth step of correcting the reference waveform according to the attenuation characteristics of the probe having the probe cable,
An ultrasonic diagnostic apparatus, wherein the probe transmits the ultrasonic wave by sending the reference waveform corrected in the fourth step to the probe cable of the probe. Control method.

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