Ultrasonic diagnostic apparatus

Abstract

To improve the accuracy of noise removal.SOLUTION: An ultrasonic diagnostic apparatus includes an ultrasonic probe, a reception part, a detection part, a comparison part, a generation part, and a noise removal part. The ultrasonic probe transmits and receives ultrasonic waves. The reception part receives a first signal from an ultrasonic probe. The detection unit detects common mode noise received by the device. The comparison unit compares the received first signal with a noise signal representing the detected common mode noise. The generator generates a second signal obtained by adjusting the noise signal based on the first signal and the noise signal. The noise removal unit removes noise based on the first signal and the second signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiments disclosed in this specification and the drawings relate to an ultrasound diagnostic device. [Background technology]

[0002] Conventionally, ultrasonic diagnostic devices equipped with an ultrasonic probe have been known. In ultrasonic diagnostic devices, an ultrasonic signal is transmitted from the ultrasonic probe, and the ultrasonic signal is reflected inside the body of a subject (patient) and returned as a reflected wave signal, which is received by the ultrasonic probe.

[0003] In an ultrasound diagnostic device, the analog reflected wave signal received by the ultrasound probe is processed by analog circuits such as amplifier circuits and filter circuits, and then converted into a digital signal by an analog-to-digital (AD) converter.The digital signal is then digitally processed to generate an image that is presented to the person performing the examination (such as a doctor).

[0004] Such an ultrasound diagnostic device is used in conjunction with medical treatment using an electric scalpel or the like. The electric scalpel is a device that generates a large amount of high-frequency output, which generates a large amount of noise. It is also known that large noise can cause artifacts in images captured by the ultrasound diagnostic device.

[0005] To address this issue, a technique has been proposed in which the signal from a dummy signal line connected to a transducer or capacitor is subtracted from the signal from the transducer actually used for diagnosis. However, this conventional technique can only remove normal mode noise because it detects noise present in the core wire of the probe cable. It is generally known that the external noise received by ultrasound diagnostic equipment is common mode noise, and this conventional technique cannot sufficiently remove artifacts. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-261441 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the embodiments disclosed in this specification and the drawings is to improve the accuracy of noise removal. However, the problem to be solved by the embodiments disclosed in this specification and the drawings is not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be positioned as other problems. [Means for solving the problem]

[0008] An ultrasound diagnostic device according to an embodiment includes an ultrasound probe, a receiving unit, a detecting unit, a comparing unit, a generating unit, and a noise removing unit. The ultrasound probe transmits and receives ultrasound waves. The receiving unit receives a first signal from the ultrasound probe. The detecting unit detects common mode noise received by the device. The comparing unit compares the received first signal with a noise signal representing the detected common mode noise. The generating unit generates a second signal by adjusting the noise signal based on the first signal and the noise signal. The noise removing unit removes noise based on the first signal and the second signal. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic apparatus according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a configuration related to a noise cancellation operation of the ultrasound diagnostic apparatus according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of the functional configuration of a control unit included in the ultrasound diagnostic apparatus according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the common mode noise detection operation of the ultrasonic diagnostic apparatus according to the embodiment. [Figure 5]FIG. 5 is a diagram illustrating an example of the calibration operation of the ultrasound diagnostic apparatus according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the noise cancellation operation of the ultrasound diagnostic apparatus according to the embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of processing executed by the ultrasound diagnostic apparatus according to the embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of processing executed by the ultrasound diagnostic apparatus according to the first modification. [Figure 9] FIG. 9 is a flowchart showing an example of processing executed by the ultrasound diagnostic apparatus according to the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0010] An ultrasound diagnostic apparatus according to an embodiment will be described below with reference to the drawings. The ultrasound diagnostic apparatus transmits an ultrasound signal from an ultrasound probe, and receives the ultrasound signal (reflected wave signal) that is reflected from inside the body of a subject (patient) by the ultrasound probe.

[0011] The ultrasound diagnostic device detects the reflected wave signal received by the ultrasound probe, performs analog signal processing on the detected analog reflected wave signal in an analog circuit, and then converts the analog signal into a digital signal using an AD converter.

[0012] The ultrasound diagnostic device performs digital processing on the digital signal using a signal processing circuit to generate an ultrasound image based on the magnitude of the reflected wave signal, and presents the generated ultrasound image to the examiner (doctor, etc.), allowing the examiner to visually confirm the condition of the tissue inside the subject's body.

[0013] 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic device 1 according to an embodiment. The ultrasound diagnostic device 1 includes, for example, an ultrasound probe 10, a pickup coil 31, a main body device 20, an input device 250, and a display device 260. While FIG. 1 shows a configuration in which the input device 250 and the display device 260 are connected to the main body device 20, the input device 250 and the display device 260 may be incorporated into the main body device 20.

[0014] The ultrasonic probe 10 is used in contact with or in close proximity to the body of the subject. The ultrasonic probe 10 emits ultrasonic signals that are directional toward the body of the subject, receives reflected wave signals, and outputs them to the main device 20.

[0015] The ultrasonic probe 10 includes a plurality of ultrasonic transducers 12. The ultrasonic transducers 12 are an example of vibration elements. For example, the ultrasonic transducers 12 are piezoelectric elements such as piezoelectric ceramics. The ultrasonic probe 10 further includes a matching layer provided on each of the ultrasonic transducers 12, and a backing material that prevents ultrasonic signals from propagating backward from the ultrasonic transducers 12 (toward the opposite side from the subject).

[0016] The ultrasonic probe 10 may be detachable from the main body device 20. The ultrasonic transducers 12 are arranged in the ultrasonic probe 10 in any arrangement manner, such as in a line or a two-dimensional array.

[0017] The pickup coil 31 detects common mode noise. The wire forming the pickup coil 31 is wound directly around an integrated shield 29 provided on a probe cable connecting the ultrasonic probe 10 and the main unit 20. For example, the pickup coil 31 detects a common mode noise current signal representing the common mode noise and outputs it to a detection unit 216 of the main unit 20. The detection unit 216 will be described later.

[0018] In this embodiment, the wire forming pickup coil 31 is wound directly around collective shield 29, but the method of installing pickup coil 31 is not limited to this. For example, the wire forming pickup coil 31 may be wound around a ferrite core (not shown) for EMC purposes that is provided on the cable of the ultrasonic probe.

[0019] By providing the pickup coil 31 as described above, the pickup coil 31 can be provided without increasing the size. Furthermore, the presence of the core can also increase the sensitivity of the pickup coil 31 to pick up common mode noise.

[0020] The main device 20 generates an ultrasound image based on the reflected wave signal output by the ultrasound probe 10. The main device 20 includes, for example, a transmission / reception circuit 21, a signal processing unit 22, a processing circuit 23, a memory circuit 24, an input interface 25, an output interface 26, and a communication interface 27.

[0021] The transmission / reception circuit 21 is controlled by the processing circuit 23 or the signal processing unit 22. The transmission / reception circuit 21 supplies a drive signal to the ultrasonic probe 10, receives a reflected wave signal output by the ultrasonic probe 10, and performs various signal processing on the reflected wave signal. The transmission / reception circuit 21 outputs a received signal generated by various signal processing to the signal processing unit 22.

[0022] The transmission / reception circuit 21 includes, for example, a pulser 212, a receiving unit 214, a detecting unit 216, and a control unit 218. The pulser 212 is a transmission circuit that supplies (applies voltage to) a drive signal (transmission pulse) to the ultrasonic transducer 12 included in the ultrasonic probe 10.

[0023] The pulser 212 supplies a drive signal for each channel. For example, the pulser 212 generates a rectangular drive signal corresponding to a pulse signal repeatedly generated at a frequency based on the clock signal output by the processing circuit 23, converts the generated drive signal into a voltage for driving the ultrasonic transducer 12, and supplies the voltage to the ultrasonic probe 10.

[0024] As a result, the ultrasonic transducer 12 transmits an ultrasonic signal in the ultrasonic probe 10. The pulser 212 includes, for example, a pair of complementary MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) and an isolation diode connected in series to each MOSFET.

[0025] The receiving unit 214 is a receiving circuit that receives the reflected wave signals output by the ultrasonic probe 10. The receiving unit 214 performs various signal processing on the received reflected wave signals for each channel to generate digital signals representing the magnitude of the received reflected wave signals, and outputs the digital signals as received signals to the signal processing unit 22. The received signals are an example of a first signal.

[0026] The receiving unit 214 uses predetermined parameters when performing various signal processing, but these can also be set, that is, changed, by the control unit 218. The receiving unit 214 includes, for each channel, components such as a transmit / receive separation switch (hereinafter referred to as "TRSW") 2141, an analog circuit, and an AD converter (hereinafter referred to as "receiving ADC") 2146.

[0027] The TRSW2141 switches the output destination of the received reflected wave signal to an analog circuit during a period when it is expected to receive the reflected wave signal (hereinafter referred to as the "reception period"). The reception period is the time required for the ultrasonic signal transmitted by the ultrasonic transducer 12 in the ultrasonic probe 10 to be received as a reflected wave signal reflected by the tissue at the deepest part of the body of the subject for which an ultrasonic image is to be generated.

[0028] The analog circuit performs analog signal processing on the reflected wave signal output by the TRSW 2141 so that a reflected wave signal of an appropriate signal level is input to the receiving ADC 2146 .

[0029] More specifically, the analog circuit performs gain correction on the reflected wave signal output by the TRSW2141 so that the receiving ADC2146 can make maximum use of the dynamic range when performing AD conversion and convert the signal into a digital signal with effective resolution.

[0030] The analog circuit includes, for example, components such as a low noise amplifier circuit (hereinafter referred to as "LNA") 2142, a variable gain amplifier circuit (hereinafter referred to as "VGA") 2143, a programmable amplifier circuit (hereinafter referred to as "PGA") 2144, and a low pass filter (hereinafter referred to as "LPF") 2145.

[0031] The LNA 2142 amplifies the amplitude of the reflected wave signal output by the TRSW 2141 with low noise based on a set gain. The gain of the LNA 2142 is a fixed gain, but can be set or changed by the control unit 218. The LNA 2142 outputs the amplified reflected wave signal to the VGA 2143 as a first LNA amplified signal.

[0032] The VGA 2143 further amplifies the first LNA amplified signal output by the LNA 2142 with a gain G that is changed depending on the time at which the reflected wave signal is received.

[0033] The strength and reception time of the reflected wave signal differ depending on the position (depth) of the tissue inside the subject's body that reflects the ultrasound signal. In other words, the reflected wave signal from tissue located shallow inside the subject's body has strong strength and a short reception time, while the reflected wave signal from tissue located deep inside the subject's body has weak strength and a long reception time.

[0034] Furthermore, the reflected wave signal has a different frequency attenuation coefficient depending on the composition of the tissue (living body) that reflects the ultrasound signal inside the subject's body. The VGA2143 amplifies the reflected wave signal (LNA amplified signal) with different reception times and attenuation coefficients based on a gain curve in which the gain G is set according to the tissue and composition.

[0035] The VGA 2143 is also called a time gain control (TGC) amplifier circuit. The gain curve of the VGA 2143 is a fixed gain curve determined for each tissue and composition of a living body, but may be corrected, or more specifically, offset, by the control unit 218. The VGA 2143 outputs the amplified reflected wave signal to the PGA 2144 as a first VGA amplified signal.

[0036] The PGA 2144 further amplifies the first VGA amplified signal amplified by the VGA 2143 based on a set gain.

[0037] The gain of the PGA 2144 is switched under the control of the control unit 218 according to the state of examination in the ultrasonic diagnostic apparatus 1, such as the operation mode of the ultrasonic diagnostic apparatus 1, the part of the subject to be examined in the ultrasonic diagnostic apparatus 1, and the configuration of the ultrasonic probe 10 connected to the ultrasonic diagnostic apparatus 1. The PGA 2144 outputs the amplified reflected wave signal to the LPF 2145 as a first PGA amplified signal.

[0038] The LPF 2145 attenuates components above a certain frequency in the first PGA amplified signal output by the PGA 2144 .

[0039] The LPF 2145 attenuates high-frequency components included in the first PGA amplified signal in accordance with the sampling frequency when the receiving ADC 2146 performs AD conversion. In other words, the LPF 2145 attenuates, for example, a reflected wave signal that exceeds the Nyquist frequency included in the first PGA amplified signal so that a reflected wave signal with a frequency that exceeds the sampling frequency of the receiving ADC 2146 is not input to the receiving ADC 2146 as high-frequency noise, aliasing noise, or the like.

[0040] The LPF 2145 is also called an anti-alias filter (AAF). The LPF 2145 outputs the reflected wave signal, in which the high-frequency components have been attenuated, to the receiving ADC 2146 as a first LPF attenuated signal.

[0041] The receiving ADC 2146 converts the analog signal that has been subjected to analog signal processing by the analog circuit into a digital signal. That is, the receiving ADC 2146 performs AD conversion on the first LPF attenuated signal output by the LPF 2145 to generate a digital signal that represents the magnitude of the reflected wave signal. The receiving ADC 2146 outputs the generated digital signal to the control unit 218 as a received signal.

[0042] The detection unit 216 is a receiving circuit that receives common mode noise detected by the pickup coil 31. The detection unit 216 is provided in parallel to the receiving units 214 that correspond to the multiple ultrasonic transducers 12 of the ultrasonic probe 10.

[0043] For example, the detection unit 216 includes the following components: an I / V (current / voltage) converter 2161, a VGA 2162, an LPF 2163, and an AD converter (hereinafter referred to as "detection ADC") 2164.

[0044] The I / V converter 2161 converts into a voltage signal the common mode noise current signal output by the pickup coil 31. In the following description, this voltage signal will also be referred to as a common mode noise voltage signal.

[0045] The VGA 2162 amplifies the common-mode noise voltage signal converted by the I / V converter 2161 with a gain G1 that is changed according to the gain G of the VGA 2143. The VGA 2162 changes the gain G1 under the control of the control unit 218. The VGA 2162 outputs the amplified common-mode noise voltage signal to the control unit 218 and the LPF 2163 as a second VGA amplified signal.

[0046] The range of change in the gain G1 of the VGA 2162 is larger than the range of change in the gain G of the VGA 2143. This is because the gain G1 of the VGA 2162 changes depending on the gain G of the VGA 2143, and if the range of change in the gain G1 of the VGA 2162 becomes smaller than the range of change in the gain G of the VGA 2143, it becomes impossible to adjust the gain G1 of the VGA 2162.

[0047] The LPF 2163 attenuates high frequency components contained in the second VGA amplified signal output by the VGA 2162 in accordance with the sampling frequency when the detection ADC 2164 performs AD conversion.

[0048] That is, the LPF 2163 attenuates the high-frequency signal included in the second VGA amplified signal so that a common-mode noise voltage signal having a frequency exceeding the sampling frequency of the detection ADC 2164 is not input to the detection ADC 2164 as high-frequency noise, aliasing noise, etc. The LPF 2163 outputs the common-mode noise voltage signal, from which the high-frequency components have been attenuated, to the receiving ADC 2146 as a second LPF attenuated signal.

[0049] The detection ADC 2164 generates a digital signal by AD converting the second LPF attenuated signal output by the LPF 2163. The detection ADC 2164 outputs the generated digital signal as a cancellation signal to the control unit 218. The detection ADC 2164 may have a larger dynamic range or higher resolution than the reception ADC 2146.

[0050] The control unit 218 comprehensively controls operations related to the transmission and reception of ultrasonic waves. For example, the control unit 218 sets the gain G of the VGA 2143. Also, for example, the control unit 218 compares the reception signal output by the reception ADC 2146 with the cancellation signal output by the detection ADC 2164. Also, for example, the control unit 218 performs control to change the gain G1 of the VGA 2162 based on the reception signal and the cancellation signal.

[0051] Also, for example, the control unit 218 outputs a signal obtained by subtracting the cancellation signal output by the detection ADC 2164 from the reception signal output by the reception ADC 2146 to the signal processing unit 22 as a subtraction signal.

[0052] Fig. 2 is a diagram showing an example of the configuration related to the noise cancellation operation in the ultrasound diagnostic device 1 according to the embodiment. Fig. 2 shows an example of the configuration of the ultrasound diagnostic device 1 to which an N-channel ultrasound probe 10 is connected.

[0053] For this reason, in the ultrasonic diagnostic device 1 shown in Fig. 2, the pulser 212 and the receiving unit 214 are connected to the ultrasonic transducer 12 of each channel. Fig. 2 also shows connections between the respective components of the receiving unit 214, namely, the TRSW 2141, the LNA 2142, the VGA 2143, the PGA 2144, the LPF 2145, and the receiving ADC 2146.

[0054] 2, each channel (channels CH-1 to CH-N) in the ultrasound diagnostic device 1 is clearly shown. In FIG. 2, for each channel, the number or letter following the "- (hyphen)" after the symbol "CH" indicates the channel number.

[0055] In the ultrasonic diagnostic device 1 shown in Fig. 2, a detection unit 216 is provided for each channel (channels CH-1 to CH-N). Fig. 2 also shows connections between the I / V converter 2161, VGA 2162, LPF 2163, and detection ADC 2164 provided in the detection unit 216 and each of the other components.

[0056] 2, the probe cables connecting the ultrasonic transducers 12 of each channel (channels CH-1 to CH-N) to the receiving unit 214 are each covered with a shield 28. The plurality of probe cables covered with the shield 28 are also covered with a collective shield 29. The wire forming the pickup coil 31 is wound directly around the collective shield 29.

[0057] In the ultrasonic diagnostic apparatus 1 shown in FIG. 2, the control unit 218 sets the gain G of the VGA 2143 to be set in the amplifier circuit in the analog circuit provided in each of the receiving units 214 of the channels CH-1 to CH-N.

[0058] The control unit 218 performs noise cancellation processing to remove common mode noise from the received signals output by the receiving units 214 of the channels CH-1 to CH-N, based on the cancellation signals output by the detection units 216 of the channels CH-1 to CH-N.

[0059] 3 is a diagram showing an example of the functional configuration of the control unit 218 included in the ultrasound diagnostic apparatus 1 according to the embodiment. The control unit 218 executes, for example, a setting function 2181, a comparison function 2182, a calibration function 2183, a noise cancellation function 2184, and the like.

[0060] Here, the comparison function 2182 is an example of a comparison unit, the calibration function 2183 is an example of a generation unit, and the noise cancellation function 2184 is an example of a noise removal unit.

[0061] The control unit 218 realizes the above functions by, for example, a hardware processor executing a program stored in a storage device (for example, the storage circuitry 24).

[0062] A hardware processor refers to a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD) or a Complex Programmable Logic Device (CPLD), or a Field Programmable Gate Array (FPGA)).

[0063] Instead of storing a program in a storage device, the program may be directly embedded in the circuit of the hardware processor. In this case, the hardware processor realizes its functions by reading and executing the program embedded in the circuit. The hardware processor is not limited to being configured as a single circuit, but may be configured as a single hardware processor by combining multiple independent circuits to realize each function.

[0064] The storage device may be a non-transitory (hardware) storage medium. Multiple components may be integrated into a single hardware processor to realize each function. Multiple components may be incorporated into a single dedicated LSI to realize each function.

[0065] Here, the program (software) may be stored in advance in a storage device (a storage device having a non-transitory storage medium) that constitutes a storage device such as a semiconductor memory element such as a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, or a hard disk drive (HDD), or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed in a storage device provided in the main unit 20 by inserting the storage medium into a drive device provided in the main unit 20.

[0066] The program (software) may be downloaded in advance from another computer device via a network and installed in a storage device provided in main device 20. The program (software) installed in the storage device provided in main device 20 may be transferred to a storage device provided in control unit 218 and executed therein.

[0067] The setting function 2181 executes processing to set the gain G of the VGA 2143 .

[0068] For example, when the setting function 2181 receives an operational instruction from the person conducting the examination via the processing circuit 23 or the input interface 25 to switch the type of ultrasound probe 10 to be used for the examination, it sets the gain G of VGA2143 to the midpoint of a predetermined change range of the gain G of VGA2143.

[0069] More specifically, if the predetermined change range of the gain G of the VGA 2143 is X to Y, the setting function 2181 sets the gain G of the VGA 2143 to X+Y / 2.

[0070] In addition, for example, the setting function 2181 performs processing to set the gain G of the VGA 2143 when the gain setting of at least one of the LNA 2142 and the PGA 2144 is changed, other than when an operational instruction to switch the type of ultrasound probe 10 to be used for the examination is received from the person conducting the examination.

[0071] Here, the setting function 2181 executes processing to set the gain G of the VGA 2162 in a state in which the ultrasound transducer 12 is not transmitting an ultrasound signal used to generate an ultrasound image. That is, the transmission / reception circuit 21 stops transmitting ultrasound waves used to generate an ultrasound image when an operation instruction to switch the type of ultrasound probe 10 used for the examination is received from the examiner or when the gain setting of at least one of the LNA 2142 and the PGA 2144 is changed.

[0072] Furthermore, since the attenuation rate of the received signal varies depending on the depth from the body surface of the subject, the setting function 2181 executes a process of changing the gain G over time while the examiner is scanning the subject.

[0073] When an instruction to start noise cancellation operation is received from the person conducting the test, the setting function 2181 may execute processing to set the gain G of the VGA 2143. For example, when an operation instruction to start noise cancellation operation is received from the person conducting the test via the processing circuit 23 or the input interface 25, the setting function 2181 may execute processing to set the gain G of the VGA 2143.

[0074] The comparison function 2182 compares the signal received by the receiver 214 with the signal detected by the detector 216 .

[0075] For example, when the setting function 2181 sets the gain G of the VGA 2143 to the midpoint of a predetermined change range of the gain G of the VGA 2143, the comparison function 2182 compares the amplitude of the received signal output by the receiving ADC 2146 with the amplitude of the cancellation signal output by the detecting ADC 2164.

[0076] More specifically, the comparison function 2182 calculates a value of the gain G1 of the VGA 2162 that makes the amplitude of the received signal equal to the amplitude of the cancellation signal. The comparison function 2182 determines whether the calculated value of the gain G1 of the VGA 2162 is within a predetermined range of change of the gain G1 of the VGA 2162.

[0077] If the calculated value of the gain G1 of the VGA 2162 is within a predetermined range of change of the gain G1 of the VGA 2162, the value of the gain G1 is sent to the calibration function 2183. On the other hand, if the calculated value of the gain G1 of the VGA 2162 is outside the predetermined range of change of the gain G1 of the VGA 2162, a warning notification indicating this is sent to the processing circuit 23 described below.

[0078] The calibration function 2183 executes control to change the gain G1 of the VGA 2162 based on the difference between the amplitude of the received signal and the amplitude of the cancellation signal.

[0079] For example, after the setting function 2181 performs processing to set the gain G of the VGA 2143, the calibration function 2183 performs control to change the gain G1 of the VGA 2162 so that the amplitude of the received signal and the amplitude of the cancellation signal become equal. Hereinafter, the above processing is also referred to as calibration of common mode noise.

[0080] Here, the calibration function 2183 performs common mode noise calibration while the ultrasonic transducer 12 is not transmitting an ultrasonic signal used to generate an ultrasonic image, similar to the process in which the setting function 2181 sets the gain G of the VGA 2143 to the midpoint of a predetermined change range of the gain G of the VGA 2143.

[0081] The noise cancellation function 2184 performs noise cancellation to remove common mode noise from the received signal. For example, the noise cancellation function 2184 subtracts the cancellation signal output by the detection ADC 2164 from the received signal output by the reception ADC 2146, and outputs the result to the signal processing unit 22.

[0082] Hereinafter, an operation related to the cancellation of common mode noise will be described with reference to Fig. 4 to Fig. 6. First, an operation related to the detection of common mode noise, which is a prerequisite, will be described. Fig. 4 is a diagram illustrating an example of the operation of detecting common mode noise. In Fig. 4, the PGA 2144, LPF 2145, and LPF 2163 are not shown.

[0083] 4, pickup coil 31 outputs the current flowing through collective shield 29 as a common-mode noise current signal to I / V converter 2161 of detection unit 216. I / V converter 2161 converts the common-mode noise current signal into a common-mode noise voltage signal and outputs it to VGA 2162.

[0084] The VGA 2162 amplifies the common-mode noise voltage signal with a predetermined gain G1. The VGA 2162 outputs a second VGA amplified signal obtained by amplifying the common-mode noise voltage signal to the LPF 2163. The LPF 2163 attenuates the high-frequency components of the second VGA amplified signal and outputs it to the detection ADC 2164 as a second LPF attenuated signal.

[0085] The detection ADC 2164 converts the second LPF attenuated signal output by the LPF 2163 into a digital signal and outputs it as a cancellation signal to the control unit 218. Here, in Figures 4 to 6, the signal processed by the detection unit 216 is represented as signal N2.

[0086] On the other hand, the reflected wave signal output by the TRSW 2141 is output to the LNA 2142 of the receiving unit 214. As described above, during calibration of the common mode noise, the ultrasonic transducer 12 does not transmit the ultrasonic signal used to generate an ultrasonic image. Therefore, in this case, a signal representing the common mode noise received by the ultrasonic diagnostic apparatus 1 is output to the LNA 2142.

[0087] The LNA 2142 amplifies the reflected wave signal (a signal representing common mode noise of the receiving unit 214). The LNA 2142 outputs the amplified reflected wave signal as a first LNA amplified signal to the VGA 2143. The VGA 2143 amplifies the first LNA amplified signal and outputs the amplified first VGA amplified signal to the PGA 2144.

[0088] The PGA 2144 further amplifies the first VGA amplified signal and outputs it as a first PGA amplified signal to the LPF 2145. The LPF 2145 attenuates the high frequency components of the first PGA amplified signal output by the PGA 2144 and outputs it to the receiving ADC 2146 as a first LPF attenuated signal.

[0089] The receiving ADC 2146 converts the first LPF attenuated signal into a digital signal and outputs it as a received signal to the control unit 218. Here, in Figures 4 to 6, the signal processed by the receiving unit 214 is represented as signal N1.

[0090] Next, calibration of common mode noise will be described. Fig. 5 is a diagram illustrating an example of the calibration operation of common mode noise. As in Fig. 4, the PGA 2144, the LPF 2145, and the LPF 2163 are not shown in Fig. 5.

[0091] First, the setting function 2181 of the control unit 218 sets the gain G of the VGA 2143 to the midpoint of the change range. Next, the comparison function 2182 calculates the value of the gain G1 of the VGA 2162 so that the amplitude of the signal N2 (common mode noise of the detection unit 216) and the amplitude of the signal N1 (common mode noise of the reception unit 214) become equal.

[0092] If the calculated value of G1 of the gain VGA2162 is outside the specified change range of the gain G1 of VGA2162, the comparison function 2182 sends a warning notification to the processing circuit 23, which includes information indicating the channel for which the calculated value of the gain G1 of VGA2162 is outside the specified change range of the gain G1 of VGA2162, and information indicating that adjustment of the gain G1 of VGA2162 is impossible.

[0093] On the other hand, if the calculated value of the gain G 1 of the VGA 2162 is within the predetermined change range of the gain G 1 of the VGA 2162 , the comparison function 2182 sends the calculated value of the gain G 1 of the VGA 2162 to the calibration function 2183 .

[0094] Next, the calibration function 2183 performs control to adjust the value of the gain G1 of the VGA 2162 to the value sent by the comparison function 2182. As a result, the amplitudes of the signals N1 and N2 output to the control unit 218 become equal. Therefore, it can be said that the calibration function 2183 adjusts the common-mode noise voltage signal to generate a cancellation signal. The cancellation signal in this case is an example of a second signal.

[0095] Hereinafter, the cancellation of common mode noise will be described with reference to Fig. 6. Fig. 6 is a diagram illustrating an example of the cancellation operation of common mode noise. As in Fig. 4, the PGA 2144, the LPF 2145, and the LPF 2163 are omitted from Fig. 6.

[0096] 6, the noise cancellation function 2184 performs a noise cancellation operation of subtracting the signal N2 output by the detection ADC 2164 from the signal N1 output by the reception ADC 2146. The noise cancellation function 2184 outputs the signal obtained by subtracting the signal N2 output by the detection ADC 2164 from the signal N1 output by the reception ADC 2146 as a subtraction signal SS to the signal processing unit 22 (not shown in FIG. 6).

[0097] Furthermore, as described above, during noise cancellation operation by the noise cancellation function 2184, the gain G of the VGA 2143 changes over time by the setting function 2181. For this reason, the calibration function 2183 performs control to change the gain G1 of the VGA 2162 in accordance with the gain G of the VGA 2143 during noise cancellation operation.

[0098] This allows the noise cancellation function 2184 to effectively remove common mode noise even if the gain G of the VGA 2143 changes over time.

[0099] The noise cancellation function 2184 may stop the noise cancellation operation when receiving an instruction to stop the noise cancellation operation from the examiner, thereby enabling the examiner to resolve any problems that may be caused by the noise cancellation operation (for example, an expected ultrasound image not being displayed, etc.).

[0100] Furthermore, in this embodiment, the noise cancellation function 2184 performs noise cancellation operation using digital signals, but the noise cancellation function 2184 may perform noise cancellation operation using analog signals.

[0101] By performing the above-described functions, the control unit 218 can effectively remove artifacts caused by extraneous noise generated by an electric scalpel or the like.

[0102] 1, the signal processing unit 22 performs image processing to generate an ultrasound image that visualizes the state of tissue inside the subject's body, based on the subtraction signal output by the control unit 218. The image processing method, etc., performed by the signal processing unit 22 is not particularly specified. The signal processing unit 22 outputs the generated ultrasound image to the output interface 26. The signal processing unit 22 also stores the generated ultrasound image in the memory circuitry 24.

[0103] The processing circuitry 23 controls the overall operation of the ultrasonic diagnostic apparatus 1. The processing circuitry 23 executes, for example, a system control function (not shown) that comprehensively controls the ultrasonic diagnostic apparatus 1. The processing circuitry 23 realizes the system control function (not shown) by, for example, a hardware processor executing a program (software) stored in a storage device (for example, the storage circuitry 24).

[0104] The hardware processor of the processing circuit 23, like the control unit 218, means a circuit such as a CPU, a GPU, an application specific integrated circuit, or a programmable logic device.

[0105] For example, the processing circuitry 23 executes a system control function (not shown) based on an input operation by the examiner received by the input interface 25, and controls various operations in the ultrasound diagnostic apparatus 1.

[0106] Also, for example, when a warning notification is sent from the control unit 218, the processing circuit 23 notifies the person conducting the test of a warning that at least one of the receiving unit 214 and the detecting unit 216 may be malfunctioning.

[0107] Specifically, the processing circuit 23 causes the display device 260 to display, via the output interface 26, a warning message indicating that there is a possibility that at least one of the receiving unit 214 and the detecting unit 216 of the channel corresponding to the information representing the channel included in the warning notification is malfunctioning.

[0108] The memory circuitry 24 stores various types of information and is realized, for example, by a semiconductor memory element such as a ROM, a RAM, or a flash memory, a hard disk drive, an optical disk, or the like.

[0109] The memory circuitry 24 stores setting data of the components included in the transmission / reception circuitry 21 (for example, the gain curve of the VGA 2143) and data of the ultrasound image output by the signal processing unit 22. The memory circuitry 24 may store in advance programs to be executed by the control unit 218 and the processing circuitry 23.

[0110] The input interface 25 accepts various input operations by the examiner using the ultrasound diagnostic apparatus 1. The input interface 25 accepts input operations performed by the examiner using an input device 250 such as a mouse, keyboard, touch panel, trackball, switch, button, joystick, camera, infrared sensor, or microphone.

[0111] The input interface 25 outputs information indicating the content of the received input operation to the processing circuitry 23. For example, when the person conducting the examination performs an input operation to adjust the gain G of the VGA 2143, the input interface 25 receives this input operation and outputs information indicating that adjustment of the gain G of the VGA 2143 has been requested to the processing circuitry 23.

[0112] In this specification, the input interface 25 or the input device 250 is not limited to those having physical operation parts such as a mouse, a keyboard, etc. For example, an example of the input interface 25 also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the main device 20 and outputs this electrical signal to the processing circuit 23.

[0113] The output interface 26 provides various information to the person performing the examination using the ultrasound diagnostic apparatus 1. For example, the output interface 26 displays the ultrasound image output by the signal processing unit 22 or the ultrasound image stored in the memory circuitry 24 by the signal processing unit 22 on a display device 260 such as a liquid crystal display (LCD), a CRT (cathode ray tube) display, or an organic EL (electroluminescence) display.

[0114] This allows the person conducting the examination to check the state of the tissue inside the body of the subject from the ultrasound image displayed on the display device 260. The output interface 26 may cause the display device 260 to display a GUI (Graphical User Interface) image or the like for receiving various input operations to the input interface 25 by the person conducting the examination.

[0115] The communication interface 27 communicates with an external device (not shown) connected via a network such as a LAN (Local Area Network) established within a hospital.

[0116] For example, the external device is a database device such as a medical image management system (PACS: Picture Archiving and Communication Systems) that manages data on various medical images, or an electronic medical record system that manages electronic medical records to which medical images such as ultrasound images from previous examinations using the ultrasound diagnostic device 1 are attached.

[0117] The external device may be other medical devices such as a computed tomography (CT) device or a magnetic resonance imaging (MRI) device located in a hospital.

[0118] Next, a description will be given of the processing executed by the ultrasound diagnostic apparatus 1. Fig. 7 is a flowchart showing an example of the processing executed by the ultrasound diagnostic apparatus 1 according to the embodiment.

[0119] First, the control unit 218 receives an instruction to switch the ultrasonic probe 10 (step S101).

[0120] For example, the control unit 218 receives an instruction to switch the type of ultrasound probe 10 to be used for the examination from the examiner via the input interface 25. Thereafter, the control unit 218 causes the ultrasound transducer 12 to stop transmitting the ultrasound signal used to generate the ultrasound image. As a result, a common mode noise current signal representing the common mode noise received by the ultrasound diagnostic device 1 is output to the I / V converter 2161 of the detection unit 216.

[0121] Next, detection unit 216 performs I / V conversion on the common mode noise current signal detected by pickup coil 31 (step S102). For example, I / V converter 2161 of detection unit 216 converts the common mode noise current signal output by pickup coil 31 into a common mode noise voltage signal.

[0122] Next, the detection unit 216 performs AD conversion on the common-mode noise voltage signal (step S103). For example, the detection ADC 2164 of the detection unit 216 generates a digital signal by AD converting the second LPF attenuated signal output by the LPF 2163 of the detection unit 216. The detection ADC 2164 outputs the generated digital signal to the control unit 218 as a cancellation signal.

[0123] Next, the comparison function 2182 of the control unit 218 determines whether the gain G1 of the VGA 2162 of the detection unit 216 can be adjusted according to the gain G of the VGA 2143 (step S104).

[0124] For example, the comparison function 2182 calculates the value of the gain G 1 of the VGA 2162 such that the amplitude of the cancellation signal output by the detection ADC 2164 is equal to the amplitude of the reception signal output by the reception ADC 2146 .

[0125] If the calculated value of gain G1 is within a predetermined variation range, the comparison function 2182 determines that the gain G1 of the VGA 2162 is adjustable according to the gain G of the VGA 2143. On the other hand, if the calculated value of gain G1 is outside the predetermined variation range, the comparison function 2182 determines that the gain G1 of the VGA 2162 is not adjustable according to the gain G of the VGA 2143.

[0126] If the gain G1 cannot be adjusted (step S104: No), the processing circuit 23 issues a warning that at least one of the receiving unit 214 and the detecting unit 216 may be malfunctioning (step S106), and ends this processing.

[0127] For example, the comparison function 2182 sends information representing the channel for which it has been determined that the gain G1 cannot be adjusted and a warning notification representing that adjustment of the gain G1 is not possible to the processing circuit 23. When the comparison function 2182 sends a warning notification, the processing circuit 23 causes the display device 260, via the output interface 26, to display a warning message representing that there is a possibility that at least one of the receiving unit 214 and the detecting unit 216 of the channel corresponding to the information representing the channel included in the warning notification is malfunctioning.

[0128] On the other hand, if the gain G1 is adjustable (step S104: Yes), the calibration function 2183 performs calibration of the common-mode noise (step S105). For example, the comparison function 2182 sends the calculated value of the gain G1 of the VGA 2162 to the calibration function 2183. The calibration function 2183 performs control to adjust the gain G1 of the VGA 2162 to that value.

[0129] Next, the noise cancellation function 2184 cancels the common mode noise (step S107). For example, the noise cancellation function 2184 subtracts the cancellation signal output by the detection ADC 2164 of the detection unit 216 from the reception signal output by the reception ADC 2146 of the reception unit 214. The noise cancellation function 2184 outputs the signal obtained by subtracting the cancellation signal from the reception signal to the signal processing unit 22 as a subtraction signal.

[0130] Here, while the examiner is scanning the subject, the setting function 2181 executes processing to change the gain G of the VGA 2143 over time in accordance with changes in the part of the subject to which ultrasound signals are transmitted and received (changes in depth from the body surface). Also, the calibration function 2183 executes processing to change the gain G1 of the VGA 2162 in accordance with changes in the gain G of the VGA 2143.

[0131] Next, the control unit 218 determines whether the gain setting of at least one of the LNA 2142 and PGA 2144 of the receiving unit 214 has been changed (step S108). If the gain setting of at least one of the LNA 2142 and PGA 2144 has been changed (step S108: Yes), the control unit 218 causes the ultrasound transducer 12 to stop transmitting the ultrasound signal used to generate the ultrasound image, and returns to the processing of S102.

[0132] On the other hand, if the gain settings of the LNA 2142 and the PGA 2144 have not been changed (step S108: No), the control unit 218 determines whether an instruction to end the scan has been received (step S109). For example, the control unit 218 determines whether an instruction to end the scan has been received from the person conducting the examination via the processing circuitry 23 or the input interface 25.

[0133] If the instruction to end the scan has not been received (step S109: No), the process returns to step S104. On the other hand, if the instruction to end the scan has been received (step S109: Yes), the process ends.

[0134] As described above, the ultrasound diagnostic device 1 according to the embodiment receives a reflected wave signal from the ultrasound transducer 12, detects common mode noise received by the ultrasound diagnostic device 1, compares the amplitude of the received signal representing the reflected wave signal with the amplitude of the noise signal representing the common mode noise, generates a cancellation signal by adjusting the noise signal based on the difference between the two, subtracts the cancellation signal from the received signal, and outputs the result.

[0135] Incidentally, ultrasound diagnostic devices are sometimes used simultaneously with devices that generate large high-frequency outputs, such as electric scalpels. It is generally known that external noise caused by electric scalpels and the like is common mode noise. As described above, the ultrasound diagnostic device 1 according to this embodiment detects common mode noise, adjusts the amplitude of the noise signal according to the amplitude of the received signal, and then subtracts it from the received signal. Therefore, the ultrasound diagnostic device 1 according to this embodiment can remove common mode noise caused by electric scalpels and the like from the received signal. Although conventional techniques for removing normal mode noise have been proposed, these conventional techniques are unable to sufficiently remove the external noise because the external noise caused by electric scalpels and the like is generally common mode noise. The ultrasound diagnostic device 1 according to this embodiment can remove common mode noise, thereby improving the accuracy of noise removal.

[0136] The above-described embodiment can be modified as needed by partially changing the configuration or functions of each device. Therefore, several modifications of the above-described embodiment will be described below as other embodiments. The following mainly focuses on differences from the above-described embodiment, and detailed descriptions of commonalities with the content already described will be omitted. The modifications described below may be implemented individually or in appropriate combination.

[0137] (Variation 1) In the above embodiment, a configuration has been described in which common mode noise calibration is performed when the ultrasonic probe 10 used for the inspection is switched and when the gain setting of at least one of the LNA 2142 and the PGA 2144 is changed. In this modified example, a configuration will be described in which common mode noise calibration is also performed every time one frame of scanning is completed.

[0138] In this modification, the control unit 218 executes common mode noise detection and common mode noise calibration every time scanning of one frame is completed. Fig. 8 is an example of a flowchart showing an example of processing executed by the ultrasound diagnostic apparatus 1 according to modification 1. The processing from step S201 to step S207 is similar to step S101 to step S107 in Fig. 7, and therefore description thereof will be omitted.

[0139] After step S207, the control unit 218 determines whether scanning of one frame is complete (step S208). If scanning of one frame is complete (step S208: Yes), the control unit 218 causes the ultrasound transducer 12 to stop transmitting the ultrasound signal used to generate the ultrasound image, and returns to the processing of S202. On the other hand, if scanning of one frame is not complete (step S208: No), the control unit 218 proceeds to the processing of step S209.

[0140] The processing from step S209 onwards is similar to the processing from step S108 onwards in FIG. 7, and therefore a description thereof will be omitted.

[0141] In this modification, when one frame of an ultrasound image is completed during noise cancellation, the process returns to detecting common mode noise, calibration is performed, and the noise cancellation operation is started again. Therefore, according to this modification, common mode noise can be effectively removed even if the positional relationship between the noise source, such as an electric scalpel, and the ultrasound probe 10 that receives the noise changes.

[0142] (Variation 2) In the above-described first modification, a configuration in which common mode noise calibration is performed each time one frame of scanning is completed has been described. In this modification, a configuration in which common mode noise calibration is performed when the operating mode (for example, B mode or Doppler mode) is switched within one frame of an ultrasound image during noise cancellation operation will be described.

[0143] In this modification, the control unit 218 detects common mode noise and calibrates the common mode noise when the operation mode is switched within one frame of an ultrasound image. Furthermore, in this modification, the detection of common mode noise and the calibration of the common mode noise are performed during transmission and reception of a signal that is not used to generate an ultrasound image and is sandwiched between switching of the operation mode. This signal is an example of a third signal.

[0144] 9 is an example of a flowchart showing an example of processing executed by the ultrasound diagnostic apparatus 1 according to Modification 2. The processing from step S301 to step S307 is similar to step S201 to step S207 in FIG. 8, and therefore description thereof will be omitted.

[0145] After step S307, the control unit 218 determines whether the operation mode has been changed (step S308). For example, the control unit 218 determines that the operation mode has been changed when an instruction to change the operation mode (for example, B mode, Doppler mode, etc.) is received from the person performing the examination via the input interface 25. In this case, the processing circuitry 23 (system control function) switches the operation mode, and therefore the system control function is an example of a switching unit.

[0146] If the operation mode has been changed (step S308: Yes), the process returns to step S302. On the other hand, if the operation mode has not been changed (step S308: No), the process proceeds to step S309.

[0147] The processing from step S309 onwards is similar to the processing from step S208 onwards in FIG. 8, and therefore a description thereof will be omitted.

[0148] In this modification, common mode noise detection and common mode noise calibration are performed during signal transmission and reception operations that are not used for generating ultrasound images and occur between switching of operation modes. As a result, this modification can prevent a decrease in frame rate due to the execution of common mode noise detection and common mode noise calibration.

[0149] (Variation 3) In the above embodiment, a configuration in which noise cancellation is performed in real time has been described. In this modified example, a configuration in which noise cancellation is performed after the fact will be described.

[0150] In this modification, the control unit 218 stores the received signal in the storage circuit 24. The control unit 218 also stores in the storage circuit 24 a cancellation signal before calibration of the common mode noise.

[0151] The calibration function 2183 adjusts the amplitude of the cancellation signal stored in the memory circuitry 24 in accordance with instructions from an operator such as a person performing the test. The noise cancellation function 2184 subtracts the cancellation signal adjusted by the calibration function 2183 from the received signal stored in the memory circuitry 24. The noise cancellation function 2184 outputs a subtraction signal obtained by subtracting the cancellation signal from the received signal to the signal processing unit 22.

[0152] The noise cancellation function 2184 may output the subtraction signal to the processing circuitry 23. In this case, the processing circuitry 23 generates an ultrasound image based on the subtraction signal.

[0153] According to this modification, it is possible to generate an ultrasound image in which artifacts caused by external noise, which are generated after the examination due to an electric scalpel or the like, have been effectively removed. Furthermore, since the amplitude of the cancellation signal can be adjusted after the examination, it is possible to more effectively remove artifacts caused by external noise. Furthermore, by repeating the adjustment of the amplitude of the cancellation signal and the generation of an ultrasound image, it is also possible to verify the validity of the current settings related to the noise cancellation operation.

[0154] According to at least one of the embodiments described above, it is possible to improve the accuracy of noise removal.

[0155] Although several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0156] 1. Ultrasound diagnostic equipment 10 Ultrasound probe 20 Main unit 21 Transmitting and receiving circuit 212 Pulsar 214 Receiving unit 2141 Transmit / Receive Separation Switch (TRSW) 2142 Low Noise Amplifier Circuit (LNA) 2143 Variable Gain Amplifier Circuit (VGA) 2144 Programmable Amplifier Circuit (PGA) 2145 Low-pass filter (LPF) 2146 Receiver (AD converter) ADC 216 Detector 2161 I / V (current / voltage) converter 2162 Variable Gain Amplifier Circuit (VGA) 2163 Low-pass filter (LPF) 2164 Detection (AD converter) ADC 218 Control Unit 2181 Setting Function 2182 Comparison Function 2183 Calibration Function 2184 Noise Cancellation Function 22 Signal processing section 23 Processing circuit 24 Memory circuit 25 Input Interface 26 Output Interface 27 Communication Interface 250 Input Devices 260 Display device

Claims

1. an ultrasonic probe for transmitting and receiving ultrasonic waves; a receiving unit that receives a first signal from the ultrasonic probe; a detection unit that detects common mode noise received by the device itself; a comparison unit that compares the received first signal with a noise signal that represents the detected common mode noise; a generation unit that generates a second signal by adjusting the noise signal based on the first signal and the noise signal; a noise removal unit that removes noise based on the first signal and the second signal; An ultrasound diagnostic device comprising:

2. the noise removal unit subtracts the second signal from the first signal and outputs the result; The ultrasonic diagnostic apparatus according to claim 1 .

3. the detection unit detects the common mode noise by detecting a current flowing through a collective shield of a probe cable of the ultrasonic probe. The ultrasonic diagnostic apparatus according to claim 1 .

4. the detection unit detects a current signal flowing through the collective shield via a pickup coil wound around the collective shield, the comparison unit converts the current signal into a voltage signal, and compares the voltage signal as the noise signal with the first signal; The ultrasonic diagnostic apparatus according to claim 3 .

5. the comparison unit compares the amplitude of the first signal with the amplitude of the noise signal; the generating unit sets a gain of a first variable gain amplifier included in the receiving unit to an intermediate value between a maximum value and a minimum value of a gain change range, and adjusts a gain of a second variable gain amplifier included in the detecting unit so that an amplitude of the first signal and an amplitude of the noise signal become equal to each other, thereby generating the second signal. The ultrasonic diagnostic apparatus according to any one of claims 1 to 4.

6. the generating unit adjusts the gain of the second variable gain amplifier in response to a change in the gain of the first variable gain amplifier. The ultrasonic diagnostic apparatus according to claim 5 .

7. the receiving unit has a low noise amplifier circuit (LNA) and a programmable amplifier circuit (PGA), the detection unit detects the common mode noise when a gain setting of at least one of the LNA and the PGA is changed; the comparison unit compares the first signal with the noise signal when a gain setting of at least one of the LNA and the PGA is changed; the generating unit generates the second signal when a gain setting of at least one of the LNA and the PGA is changed. The ultrasonic diagnostic apparatus according to claim 5 .

8. the detector detects the common mode noise every time one frame of an ultrasound image generated based on a subtraction signal obtained by subtracting the second signal from the first signal is completed; the comparison unit compares the first signal with the noise signal every time one frame ends, the generation unit generates the second signal every time one frame ends. The ultrasonic diagnostic apparatus according to claim 5 .

9. a switching unit for switching between operation modes of the device itself, the operation modes including at least a B-mode and a Doppler mode; When the operation mode is switched, the detection unit detects the common mode noise during a transmission / reception operation of a third signal that is not used for generating an ultrasound image and is sandwiched when the operation mode is switched, comparing the first signal with the noise signal during the transmission / reception operation of the third signal; the generation unit generates the second signal during a transmission / reception operation of the third signal. The ultrasonic diagnostic apparatus according to claim 5 .

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