Ultrasound diagnostic device and method for operating the ultrasound diagnostic device

Abstract

To provide an ultrasonic diagnostic apparatus capable of polarization processing of ultrasonic vibrators without affecting image quality of an ultrasonic image or without changing a circuit structure considerably by using an existing transmission circuit.SOLUTION: A control circuit of an ultrasonic diagnostic apparatus having an ultrasonic endoscope controls a transmission circuit so as to generate a transmission signal composed of diagnostic driving pulse to be applied to a plurality of ultrasonic vibrators respectively that generate ultrasonic waves for acquiring an ultrasonic image when acquiring the ultrasonic image, and controls the transmission circuit so as to generate polarization driving pulse of frequency different from probe frequency bandwidth for acquiring the ultrasonic image that is different drive voltage for polarization in the same voltage range that can be set as the diagnosis driving pulse for performing polarization processing of the plurality of ultrasonic vibrators when performing the polarization processing.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] The present invention relates to an ultrasonic diagnostic apparatus that performs polarization processing on a plurality of ultrasonic transducers provided in an ultrasonic endoscope, and a method for operating the ultrasonic diagnostic apparatus. [Background technology]

[0002] As an ultrasound diagnostic device for observing the biliary and pancreatic organs through the digestive tract, an ultrasound endoscope with an ultrasound observation unit at the tip of the endoscope is used. Such an ultrasound diagnostic device obtains an ultrasound image of the inside of the body cavity of the subject by driving multiple ultrasound transducers in the body cavity of the subject to transmit and receive ultrasound waves. It is necessary to avoid a decrease in sensitivity of this ultrasound diagnostic device when it is inserted into the body cavity of the subject. In an ultrasonic diagnostic device, a plurality of ultrasonic transducers are formed, for example, of single crystal transducers, which are piezoelectric elements, and are usually used in a polarized state. Although ultrasonic transducers formed of single crystal transducers can receive ultrasonic waves with high sensitivity, a depolarization phenomenon may occur in which the degree of polarization decreases as the driving time increases. When a depolarization phenomenon occurs, the reception sensitivity of the ultrasonic transducer decreases, which may affect the image quality of an ultrasonic image. For this reason, it is also known that, as a measure against the depolarization of a single crystal transducer, sensitivity can be restored by performing a repolarization process (also simply called a polarization process).

[0003] The risk of depolarization is correlated with the thickness of the vibrator, i.e., the resonant frequency, and the thicker (lower frequency) the vibrator is, the lower the risk. Therefore, when using a vibrator using a single crystal vibrator for body surface use, the risk of depolarization is avoided by using a low frequency band of 1 to 6 MHz (see Patent Document 1). On the other hand, when transmitting and receiving ultrasonic waves by driving each ultrasonic transducer in the body cavity of the subject, the frequency of the ultrasonic waves needs to be set to a high frequency band of 7 to 8 MHz, so that a relatively thin transducer is used, but the thinner the transducer, the higher the risk of depolarization phenomenon. Therefore, a repolarization process is required for a thin transducer (see Patent Documents 2 and 3).

[0004] For this reason, techniques for depolarization in ultrasonic diagnostic devices have been developed. To give an example, an ultrasonic sensor as a piezoelectric sensor device described in Patent Document 1 includes a piezoelectric element having a piezoelectric body and a pair of electrodes sandwiching the piezoelectric body, a detection circuit that performs detection processing to detect a detection signal output from the piezoelectric element, and a dedicated polarization processing circuit that applies a polarization voltage to the piezoelectric element to perform polarization processing. In the ultrasonic sensor described in Patent Document 1 having such a configuration, the detection circuit detects depolarization from the difference in characteristics between the piezoelectric elements, and a dedicated polarization processing circuit is used to perform polarization processing, thereby recovering polarization. Note that the polarization processing is performed, for example, when the power is turned on, when a request signal to perform detection processing is input (every reception timing), or when a predetermined standby transition time has elapsed after the detection processing is completed. As a result, even if a depolarization phenomenon occurs in the piezoelectric element, the piezoelectric element can be polarized again, and the reception sensitivity of the piezoelectric element can be maintained.

[0005] As another example, the ultrasonic sensor described in Patent Document 2 has a piezoelectric element and a drive circuit for driving the piezoelectric element. The drive circuit drives the piezoelectric element with a drive waveform having a process of first maintaining the polarization of the piezoelectric element with a first potential V1, then applying a maximum potential VH and a minimum potential VL at least once each to the piezoelectric element to transmit ultrasonic waves, then making the piezoelectric element wait at a second potential V2, then raising the second potential V2 to a third potential V3, then maintaining the third potential V3 while the piezoelectric element receives ultrasonic waves, and then returning the third potential V3 to the first potential V1. In the ultrasonic diagnostic device described in Patent Document 2 having such a configuration, the piezoelectric element is driven with a drive waveform having the above six processes, thereby making it possible to drive the piezoelectric element while maintaining the polarization of the piezoelectric element. That is, Patent Document 2 describes that depolarization is prevented by devising a waveform for driving the piezoelectric element.

[0006] In addition, the ultrasound device described in Patent Document 3 has an ultrasound transducer that transmits and receives ultrasound to and from the subject, and a transmission / reception circuit that has a power supply circuit, a transmission pulse output unit, a heating pulse output unit, a polarization voltage output unit, a reception beamformer, and a polarization control unit, or an integrated circuit that further has a temperature detection unit in addition to the transmission / reception circuit. The ultrasonic device described in Patent Document 3 has a heating pulse output unit and a polarization voltage output unit provided separately from the transmission pulse output unit, and outputs a heating pulse from the heating pulse output unit to the ultrasonic transducer to heat the ultrasonic transducer, and outputs a required DC polarization voltage from the polarization voltage output unit to the ultrasonic transducer to polarize the ultrasonic transducer. The technology described in Patent Document 3 claims that the polarization voltage, which is higher than the voltage of the transmission pulse output from the transmission pulse output unit to the ultrasonic transducer to transmit ultrasonic waves at room temperature, can be made lower than that at room temperature by heating the ultrasonic transducer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-005137 A (Patent No. 5874208) [Patent Document 2] JP 2017-143353 A [Patent Document 3] Patent No. 6158017 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, in the ultrasonic sensors and ultrasonic devices described in Patent Documents 1, 2, and 3, it is possible to restore or maintain the polarization of the piezoelectric element made of a piezoelectric body and the polarization of the ultrasonic transducer. However, as with the ultrasonic sensor described in Patent Document 1, the provision of a dedicated circuit for re-polarization and a mechanism for detecting depolarization, etc., requires significant hardware modifications, and there is a problem that it is very difficult to install in existing systems. In addition, in the ultrasonic sensor described in Patent Document 2, in order to prevent depolarization and maintain polarization, a direct current component is inserted into each drive waveform, which lengthens the pulse length of the drive waveform, resulting in a problem that the frame rate may decrease and affect the image quality of the ultrasonic image. In addition, preventing depolarization using such drive waveforms involves a trade-off between image quality and the risk of depolarization.

[0009] In addition, in the ultrasonic device described in Patent Document 3, repolarization can be performed by the ultrasonic device alone, but since the same integrated circuit or transmitting / receiving circuit outputs the transmission pulse, the heating pulse, and the polarization voltage, which is a DC voltage, there is a problem that the circuit scale becomes large, leading to increased costs. Furthermore, in the ultrasound device described in Patent Document 3, it is necessary to heat the ultrasound transducer. However, when applied to an ultrasound endoscope used inside the body cavity of a subject, there is a problem that heating during endoscopic examination causes an undesirable rise in the temperature of the tip of the probe.

[0010] An object of the present invention is to provide an ultrasonic diagnostic device and an operating method for an ultrasonic diagnostic device, which can perform polarization processing of an ultrasonic transducer during non-diagnostic times different from the times when ultrasonic images are acquired, using an existing transmission circuit that transmits a transmission signal to the ultrasonic transducer of an ultrasonic endoscope, without affecting the image quality of the ultrasonic image and without requiring a significant change in the circuit configuration or an increase in the circuit size. [Means for solving the problem]

[0011] In order to achieve the above object, an ultrasonic diagnostic device according to a first aspect of the present invention is an ultrasonic diagnostic device for acquiring ultrasonic images and endoscopic images, and includes an ultrasonic endoscope including an ultrasonic observation unit that transmits ultrasonic waves using an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged and receives reflected waves of the ultrasonic waves, and an ultrasonic processor device including a transmission circuit that transmits transmission signals to the plurality of ultrasonic transducers in order to generate ultrasonic waves from the plurality of ultrasonic transducers, a reception circuit that outputs reception signals based on reflected waves received by the plurality of ultrasonic transducers, and an ultrasonic image generation unit that visualizes the reception signals and generates an ultrasonic image in order to acquire an ultrasonic image, wherein all of the plurality of ultrasonic transducers are single crystal transducers, and the thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, and The processor device further includes a control circuit which transmits ultrasonic waves and receives reflected waves, and which performs polarization processing on the multiple ultrasonic transducers using the transmission circuit. When acquiring an ultrasonic image, the control circuit controls the transmission circuit to generate a transmission signal consisting of a diagnostic drive pulse to be applied to each of the multiple ultrasonic transducers that generate ultrasonic waves to acquire an ultrasonic image. When performing polarization processing, the control circuit controls the transmission circuit to generate polarization drive pulses which are polarization drive voltages with different magnitudes within the same settable voltage range as the diagnostic drive pulse and have a frequency different from the probe frequency band for acquiring an ultrasonic image, in order to perform polarization processing on the multiple ultrasonic transducers. The control circuit applies the polarization drive pulses to the multiple ultrasonic transducers, and performs polarization processing on the multiple ultrasonic transducers with the polarization drive pulses.

[0012] Here, it is preferable that the control circuit controls the transmission circuit so that the probe frequency band and the frequency band of the main lobe of the drive waveform of the polarization drive pulse that drives multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more. Moreover, it is preferable that the frequency band of the main lobe of the drive waveform of the polarization drive pulse is lower than the probe frequency band. In addition, it is preferable that the sensitivities of one or more side lobes that occur concomitantly within the probe frequency band relative to the main lobe of the drive waveform of the polarization drive pulse are all -10 dB or less, and the average sensitivity of the one or more side lobes is -20 dB or less. Moreover, the frequency band of the main lobe of the driving waveform of the polarization driving pulse is preferably 2.3 MHz or less. Moreover, the probe frequency band is preferably from 2.7 MHz to 11.7 MHz.

[0013] Moreover, the driving waveform of the polarization driving pulse is preferably a unipolar waveform. Moreover, it is preferable that the transmission circuit outputs, as the polarization drive pulse, a plurality of unipolar waveforms with an interval between each of the waveforms equal to a minimum number of clocks defined in the transmission circuit. Moreover, it is preferable that the polarization driving voltage is higher than the imaging driving voltage of the diagnostic driving pulse. In addition, it is preferable that the imaging drive voltage of the diagnostic drive pulse and the polarization drive voltage of the polarization drive pulse have the same settable voltage range, and that the transmission circuit switches between the imaging drive voltage and the polarization drive voltage. In addition, it is preferable that the multiple ultrasonic transducers on the ultrasonic transducer array are grouped into multiple groups, and the ultrasonic transducers in each group are independently polarized by a transmission signal that performs a different polarization process for each group.

[0014] In order to achieve the above object, a method of operating an ultrasonic diagnostic apparatus according to a second aspect of the present invention is a method of operating an ultrasonic diagnostic apparatus for acquiring ultrasonic images and endoscopic images, the ultrasonic diagnostic apparatus comprising: an ultrasonic endoscope having an ultrasonic observation unit having an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged; and an ultrasonic processor device having a transmission circuit for transmitting transmission signals to the plurality of ultrasonic transducers, a reception circuit for outputting reception signals based on reflected waves received by the plurality of ultrasonic transducers, and an ultrasonic image generating unit for imaging the reception signals to generate an ultrasonic image, the plurality of ultrasonic transducers are all single crystal transducers, the thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, and the transmission circuit is controlled to generate transmission signals consisting of diagnostic drive pulses to be applied to the plurality of ultrasonic transducers that generate ultrasonic waves to acquire an ultrasonic image. the step of controlling the transmission circuit to generate a polarization drive pulse having a different polarization drive voltage within the same settable voltage range as the diagnostic drive pulse and a frequency different from the probe frequency band for acquiring an ultrasonic image, in order to perform polarization processing of the multiple ultrasonic transducers, and the step of applying the polarization drive pulse to the multiple ultrasonic transducers to perform polarization processing of the multiple ultrasonic transducers with the polarization drive pulse.

[0015] Here, in the step of controlling the transmission circuit to generate a transmission signal consisting of a diagnostic drive pulse, it is preferable to control the transmission circuit so that the probe frequency band and the frequency band of the main lobe of the drive waveform of the polarization drive pulse that drives multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more. Moreover, it is preferable that the frequency band of the main lobe of the drive waveform of the polarization drive pulse is lower than the probe frequency band. In addition, it is preferable that the sensitivities of one or more side lobes that occur concomitantly within the probe frequency band relative to the main lobe of the drive waveform of the polarization drive pulse are all -10 dB or less, and the average sensitivity of the one or more side lobes is -20 dB or less. Moreover, it is preferable that the frequency band of the main lobe of the driving waveform of the polarization driving pulse is 2.3 MHz or less. Moreover, the probe frequency band is preferably from 2.7 MHz to 11.7 MHz.

[0016] The driving waveform of the polarization driving pulse is preferably a unipolar waveform. In addition, it is preferable that the step of controlling the transmission circuit to generate a polarization drive pulse controls the transmission circuit to output a plurality of unipolar waveforms as the polarization drive pulse, with a waveform spacing of a minimum number of clocks specified in the transmission circuit. Moreover, it is preferable that the polarization driving voltage is higher than the imaging driving voltage of the diagnostic driving pulse. In addition, it is preferable that the imaging drive voltage of the diagnostic drive pulse and the polarization drive voltage of the polarization drive pulse have the same settable voltage range, and that the transmission circuit switches between the imaging drive voltage and the polarization drive voltage. In addition, it is preferable that the plurality of ultrasonic transducers on the ultrasonic transducer array are grouped into a plurality of groups, and the ultrasonic transducers in each group are independently polarized by different transmission signals that perform polarization processing for each group. Effect of the Invention

[0017] According to the present invention, the polarization process of the multiple ultrasonic transducers is performed during a non-diagnostic time that is different from the time when the ultrasonic image is acquired. Therefore, the reception sensitivity of the multiple ultrasonic transducers can be always kept good without deteriorating the image quality of the ultrasonic image, and therefore, high-quality ultrasonic images can always be acquired without affecting the image quality of the ultrasonic image. In addition, according to the present invention, polarization processing of multiple ultrasonic transducers is performed using an existing transmission circuit that transmits a transmission signal to the ultrasonic transducer of an ultrasonic endoscope, so that polarization processing of the ultrasonic transducers can be performed without significantly changing the existing circuit configuration and without causing an increase in the circuit size. According to the present invention, it is possible to provide an ultrasonic diagnostic apparatus having a high-sensitivity ultrasonic endoscope that can repolarize with an optimal waveform for the polarization of a single crystal vibrator even when the single crystal vibrator is used, and it is also possible to provide a method of operating an ultrasonic diagnostic apparatus that can repolarize with an optimal waveform for the polarization of the single crystal vibrator in a high-sensitivity ultrasonic endoscope. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram showing a schematic configuration of an ultrasound diagnostic apparatus according to an embodiment of the present invention. [Diagram 2] 2 is a plan view showing the tip of the insertion section of the ultrasonic endoscope shown in FIG. 1 and its periphery. [Diagram 3] 3 is a diagram showing a cross section of the tip portion of the insertion section of the ultrasonic endoscope shown in FIG. 2 taken along cross section II shown in FIG. 2. [Figure 4] FIG. 2 is a block diagram showing the configuration of the ultrasonic processor device shown in FIG. [Figure 5A] 5 is a graph showing an example of a driving waveform of a polarization driving pulse transmitted from the transmission circuit shown in FIG. [Figure 5B] 5B is a graph showing the relationship between the sensitivity and frequency of the driving waveform of the polarization driving pulse shown in FIG. 5A. [Figure 6A] 5 is a graph showing another example of a driving waveform of a polarization driving pulse transmitted from the transmission circuit shown in FIG. [Figure 6B] 6B is a graph showing the relationship between the sensitivity and frequency of the drive waveform of the polarization drive pulse shown in FIG. 5A and the drive waveform of the polarization drive pulse shown in FIG. 6A. [Figure 7A] 5 is a graph showing another example of a pulse waveform of a polarization driving pulse transmitted from the transmission circuit shown in FIG. [Figure 7B]7B is a graph showing the relationship between the sensitivity and frequency of the driving waveform of the polarization driving pulse shown in FIG. 7A. [Figure 7C] 5 is a graph showing another example of a pulse waveform of a polarization driving pulse transmitted from the transmission circuit shown in FIG. [Figure 7D] 7D is a graph showing the relationship between the sensitivity and frequency of the driving waveform of the polarization driving pulse shown in FIG. 7C. [Figure 8A] 5 is a graph showing another example of a pulse waveform of the diagnostic driving pulse transmitted from the transmission circuit shown in FIG. [Figure 8B] 8B is a graph showing the relationship between the sensitivity and frequency of the drive waveform of the diagnostic drive pulse shown in FIG. 8A. [Figure 9] 2 is a diagram showing a flow of diagnostic processing using the ultrasonic diagnostic apparatus shown in FIG. 1. [Figure 10] FIG. 11 is a diagram showing a procedure of diagnostic steps during diagnostic processing. [Figure 11] FIG. 13 is a diagram showing a process flow when performing polarization processing. [Figure 12] FIG. 2 is a conceptual diagram showing an example of scan timing of a plurality of scan lines scanned by electronic sector scanning during an ultrasound diagnosis. [Figure 13] FIG. 2 is a conceptual diagram of an example illustrating a plurality of scanning lines. [Figure 14] 1 is a conceptual diagram showing an example of timing for scanning scan lines and timing for supplying a transmission signal for performing polarization processing when performing polarization processing during an ultrasound diagnosis. FIG. [Figure 15] FIG. 13 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the line density of scanning lines for performing ultrasonic diagnosis is reduced. [Figure 16] FIG. 11 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the number of scanning lines for performing ultrasonic diagnosis is reduced. [Figure 17] FIG. 11 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the line spacing of scanning lines for performing ultrasonic diagnosis is reduced. [Figure 18]FIG. 1 is a conceptual diagram showing an example of the timing of supplying a transmission signal to extend the time for which polarization processing is performed on an ultrasonic transducer located in the center rather than at either end when performing polarization processing during an ultrasonic diagnosis. [Figure 19] 1 is a conceptual diagram of an example showing ultrasonic transducers at a center portion and both ends. [Figure 20] FIG. 13 is a conceptual diagram illustrating an example of a display mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ultrasonic diagnostic apparatus according to an embodiment of the present invention will be described in detail below based on a preferred embodiment shown in the accompanying drawings. It should be noted that the present embodiment is a typical embodiment of the present invention, but is merely an example and does not limit the present invention. In addition, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower limit and upper limit.

[0020] <<Overview of Ultrasound Diagnostic Equipment>> An overview of an ultrasonic diagnostic apparatus 10 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of the ultrasonic diagnostic apparatus 10. The ultrasound diagnostic device 10 is used to observe the condition of an observation target part inside the body of a patient, who is a subject, using ultrasound (hereinafter, also referred to as ultrasound diagnosis). Here, the observation target part is a part that is difficult to examine from the surface of the patient's body, such as the gallbladder or pancreas. By using the ultrasound diagnostic device 10, it is possible to perform ultrasound diagnosis of the condition of the observation target part and the presence or absence of abnormality via the digestive tract, such as the esophagus, stomach, duodenum, small intestine, and large intestine, which are body cavities of the patient. The ultrasonic diagnostic device 10 acquires ultrasonic images and endoscopic images, and as shown in FIG. 1, includes an ultrasonic endoscope 12, an ultrasonic processor 14, an endoscopic processor 16, a light source device 18, a monitor 20, a water tank 21a, a suction pump 21b, and an operation console 100.

[0021] The ultrasonic endoscope 12 is an endoscopic scope and includes an insertion section 22 to be inserted into a patient's body cavity, an operation section 24 operated by an operator (user) such as a doctor or technician, and an ultrasonic transducer unit 46 (see Figs. 2 and 3) attached to a tip section 40 of the insertion section 22. Using the functions of the ultrasonic endoscope 12, the operator obtains an endoscopic image of the inner wall of the patient's body cavity and an ultrasonic image of the observation target site. Here, an "endoscopic image" is an image obtained by photographing the inner wall of a patient's body cavity using an optical method, while an "ultrasound image" is an image obtained by receiving reflected waves (echoes) of ultrasound transmitted from inside the patient's body cavity toward the observation target site and converting the received signals into an image. The ultrasonic endoscope 12 will be described in detail later.

[0022] The ultrasonic processor 14 is connected to the ultrasonic endoscope 12 via the universal cord 26 and an ultrasonic connector 32a provided at the end of the universal cord 26. The ultrasonic processor 14 controls the ultrasonic transducer unit 46 of the ultrasonic endoscope 12 to transmit ultrasonic waves. The ultrasonic processor 14 also generates an ultrasonic image by imaging a reception signal when the ultrasonic transducer unit 46 receives a reflected wave (echo) of the transmitted ultrasonic wave. The ultrasonic processor 14 will be described in detail later.

[0023] The endoscope processor 16 is connected to the ultrasonic endoscope 12 via the universal cord 26 and an endoscope connector 32b provided at the end of the universal cord 26. The endoscope processor 16 acquires image data of an area adjacent to the observation target imaged by the ultrasonic endoscope 12 (more specifically, a solid-state image sensor 86, which will be described later), and performs predetermined image processing on the acquired image data to generate an endoscopic image. Here, the "site adjacent to the observation target" refers to a portion of the inner wall of the patient's body cavity that is located adjacent to the observation target site. In this embodiment, the ultrasonic processor 14 and the endoscope processor 16 are configured by two devices (computers) that are provided separately. However, this is not limited to this, and both the ultrasonic processor 14 and the endoscope processor 16 may be configured by one device.

[0024] The light source device 18 is connected to the ultrasonic endoscope 12 via the universal cord 26 and a light source connector 32c provided at the end of the universal cord 26. When imaging an area adjacent to the observation target using the ultrasonic endoscope 12, the light source device 18 irradiates white light or specific wavelength light consisting of three primary colors of red, green, and blue light. The light irradiated by the light source device 18 propagates through the ultrasonic endoscope 12 via a light guide (not shown) contained in the universal cord 26, and is emitted from the ultrasonic endoscope 12 (more specifically, an illumination window 88 described later). As a result, the area adjacent to the observation target is illuminated by the light from the light source device 18.

[0025] The monitor 20 is connected to the ultrasonic processor 14 and the endoscope processor 16, and displays the ultrasonic image generated by the ultrasonic processor 14 and the endoscopic image generated by the endoscope processor 16. The ultrasonic image and the endoscopic image may be displayed on the monitor 20 by switching between either one of the images, or may be displayed simultaneously. The display modes of the ultrasonic image and the endoscopic image will be described later. In this embodiment, the ultrasound image and the endoscopic image are displayed on one monitor 20, but a monitor for displaying the ultrasound image and a monitor for displaying the endoscopic image may be provided separately. Furthermore, the ultrasound image and the endoscopic image may be displayed in a display format other than that of the monitor 20, for example, on a display of a terminal carried by the surgeon.

[0026] The operation console 100 is a device provided for an operator to input necessary information for ultrasonic diagnosis and to instruct the ultrasonic processor 14 to start ultrasonic diagnosis. The operation console 100 is composed of, for example, a keyboard, a mouse, a trackball, a touch pad, a touch panel, etc. When the operation console 100 is operated, a CPU (control circuit) 152 (see FIG. 4) of the ultrasonic processor 14 controls each part of the device (for example, a receiving circuit 142 and a transmitting circuit 144 described later) according to the operation content.

[0027] Specifically, before starting an ultrasound diagnosis, the surgeon inputs examination information (e.g., examination order information including the date and order number, and patient information including the patient ID and patient name) into the operation console 100. After inputting the examination information, the surgeon issues an instruction to start an ultrasound diagnosis through the operation console 100, and the CPU 152 of the ultrasound processor 14 controls each part of the ultrasound processor 14 so that an ultrasound diagnosis is performed based on the input examination information. Furthermore, when performing an ultrasound diagnosis, the surgeon can set various control parameters on the console 100. Examples of the control parameters include the selection result of live mode and freeze mode, the setting value of the display depth, and the selection result of the ultrasound image generation mode. Here, the "live mode" is a mode in which ultrasound images (moving images) obtained at a predetermined frame rate are sequentially displayed (real-time display). The "freeze mode" is a mode in which one frame image (still image) of an ultrasound image (moving image) generated in the past is read out from the cine memory 150 described later and displayed.

[0028] In this embodiment, there are a plurality of selectable ultrasound image generating modes, specifically, B (Brightness) mode, CF (Color Flow) mode, and PW (Pulse Wave) mode. B mode is a mode in which the amplitude of an ultrasound echo is converted to brightness to display a tomographic image. CF mode is a mode in which the average blood flow velocity, flow fluctuation, strength of a flow signal, flow power, etc. are mapped to various colors and displayed superimposed on a B-mode image. PW mode is a mode in which the velocity of an ultrasound echo source (e.g., blood flow velocity) detected based on transmission and reception of a pulse wave is displayed. The above-mentioned ultrasound image generation modes are merely examples, and other modes than the three modes mentioned above, such as A (Amplitude) mode, M (Motion) mode, and contrast mode, may be included, and a mode for obtaining a Doppler image may be included.

[0029] <<Configuration of the ultrasonic endoscope 12>> Next, the configuration of the ultrasonic endoscope 12 will be described with reference to the already-mentioned Fig. 1 and Fig. 2 to Fig. 4. Fig. 2 is an enlarged plan view showing the tip of the insertion section 22 of the ultrasonic endoscope 12 and its surroundings. Fig. 3 is a cross-sectional view showing a cross section of the tip 40 of the insertion section 22 of the ultrasonic endoscope 12 taken along section II shown in Fig. 2. As described above, the ultrasonic endoscope 12 has the insertion section 22 and the operation section 24. As shown in Fig. 1, the insertion section 22 has, in order from the tip side (free end side), a tip section 40, a bending section 42, and a flexible section 43. The tip section 40 is provided with an ultrasonic observation section 36 and an endoscopic observation section 38 as shown in Fig. 2. The ultrasonic observation section 36 has an ultrasonic transducer unit 46 equipped with a plurality of ultrasonic transducers 48 arranged therein as shown in Fig. 3. 2, a treatment tool outlet 44 is provided at the tip 40. The treatment tool outlet 44 serves as an outlet for treatment tools (not shown) such as forceps, a puncture needle, or a high-frequency scalpel. The treatment tool outlet 44 also serves as a suction port when aspirating blood, internal waste, and other substances.

[0030] The bending section 42 is a section provided on the base end side (opposite the side where the ultrasonic transducer unit 46 is provided) of the distal end section 40, and is freely bendable. The flexible section 43 is a section that connects the bending section 42 and the operation section 24, and is provided in a flexible and elongated state. A plurality of ducts for supplying air and water and a plurality of ducts for suction are formed inside each of the insertion section 22 and the operation section 24. Furthermore, a treatment tool channel 45, one end of which leads to a treatment tool outlet 44, is formed inside each of the insertion section 22 and the operation section 24. Next, among the components of the ultrasonic endoscope 12, the ultrasonic observation section 36, the endoscopic observation section 38, the water tank 21a, the suction pump 21b, and the operation section 24 will be described in detail.

[0031] (Ultrasound Observation Department) The ultrasonic observation section 36 is a section provided for acquiring ultrasonic images, and is disposed on the distal end side of the distal end portion 40 of the insertion section 22. The ultrasonic observation section 36 includes an ultrasonic transducer unit 46, a plurality of coaxial cables 56, and an FPC (Flexible Printed Circuit) 60, as shown in FIG. The ultrasonic transducer unit 46 corresponds to an ultrasonic probe, and transmits ultrasonic waves using an ultrasonic transducer array 50 in which a plurality of ultrasonic transducers 48 described later are arranged in a patient's body cavity, and receives reflected waves (echoes) of ultrasonic waves reflected at a target observation site, and outputs a reception signal. The ultrasonic transducer unit 46 according to this embodiment is a convex type, and transmits ultrasonic waves radially (arc-shaped). However, the type (model) of the ultrasonic transducer unit 46 is not particularly limited to this, and other types may be used as long as they can transmit and receive ultrasonic waves, such as a sector type, a linear type, and a radial type.

[0032] As shown in FIG. 3, the ultrasonic transducer unit 46 is configured by laminating a backing material layer 54, an ultrasonic transducer array 50, an acoustic matching layer 74, and an acoustic lens 76. The ultrasonic transducer array 50 is composed of a plurality of ultrasonic transducers 48 (ultrasonic transducers) arranged in a one-dimensional array. More specifically, the ultrasonic transducer array 50 is configured by arranging N (e.g., N=128) ultrasonic transducers 48 at equal intervals in a convex curved shape along the axial direction of the tip portion 40 (the longitudinal axis direction of the insertion portion 22). The ultrasonic transducer array 50 may be configured by arranging a plurality of ultrasonic transducers 48 in a two-dimensional array.

[0033] Each of the N ultrasonic transducers 48 is configured by arranging electrodes on both sides of a single crystal transducer, which is a piezoelectric element. As the single crystal transducer, any of quartz crystal, lithium niobate, lead magnesium niobate (PMN), lead magnesium niobate-lead titanate (PMN-PT), lead zinc niobate (PZN), lead zinc niobate-lead titanate (PZN-PT), lead indium niobate (PIN), lead titanate (PT), lithium tantalate, langasite, and zinc oxide is used. The electrodes are composed of individual electrodes (not shown) provided individually for each of the multiple ultrasonic transducers 48, and a transducer ground (not shown) common to the multiple ultrasonic transducers 48. The electrodes are electrically connected to the ultrasonic processor 14 via a coaxial cable 56 and an FPC 60.

[0034] The ultrasonic transducer 48 according to this embodiment needs to be driven (vibrated) at a relatively high frequency of 7 MHz to 8 MHz in order to obtain an ultrasonic image of the inside of a patient's body cavity. For this reason, the thickness of the piezoelectric element constituting the ultrasonic transducer 48 is designed to be relatively thin, for example, 75 μm to 125 μm, and preferably 90 μm to 110 μm. A diagnostic drive pulse, which is a pulsed drive voltage, is supplied to each ultrasonic transducer 48 as an input signal (transmission signal) from the ultrasonic processor 14 through a coaxial cable 56. When this drive voltage is applied to the electrodes of the ultrasonic transducer 48, the piezoelectric element expands and contracts, and the ultrasonic transducer 48 is driven (vibrates). As a result, a pulsed ultrasonic wave is output from the ultrasonic transducer 48. At this time, the amplitude of the ultrasonic wave output from the ultrasonic transducer 48 corresponds to the intensity (output intensity) when the ultrasonic transducer 48 outputs the ultrasonic wave. Here, the output intensity is defined as the magnitude of the sound pressure of the ultrasonic wave output from the ultrasonic transducer 48.

[0035] Furthermore, when each ultrasonic transducer 48 receives a reflected ultrasonic wave (echo), it vibrates (drives) accordingly, and the piezoelectric element of each ultrasonic transducer 48 generates an electric signal. This electric signal is output from each ultrasonic transducer 48 to the ultrasonic processor device 14 as an ultrasonic reception signal. At this time, the magnitude (voltage value) of the electric signal output from the ultrasonic transducer 48 corresponds to the reception sensitivity when the ultrasonic transducer 48 receives the ultrasonic wave. Here, the reception sensitivity is defined as the ratio of the amplitude of the electric signal output by the ultrasonic transducer 48 after receiving the ultrasonic wave to the amplitude of the ultrasonic wave transmitted by the ultrasonic transducer 48.

[0036] In this embodiment, the N ultrasonic transducers 48 are sequentially driven by an electronic switch such as a multiplexer 140 (see FIG. 4 ), and ultrasonic waves are scanned in a scanning range along the curved surface on which the ultrasonic transducer array 50 is arranged, for example, a range of about several tens of mm from the center of curvature of the curved surface. To explain in more detail, when a B-mode image (tomographic image) is acquired as an ultrasonic image, a driving voltage is supplied to m (for example, m=N / 2) ultrasonic transducers 48 (hereinafter referred to as driven transducers) that are arranged consecutively among the N ultrasonic transducers 48 by selecting an aperture channel of the multiplexer 140. This drives the m driven transducers, and ultrasonic waves are output from each driven transducer of the aperture channel. The ultrasonic waves output from the m driven transducers are immediately synthesized, and the synthesized wave (ultrasonic beam) is transmitted toward the observation target site. Thereafter, each of the m driven transducers receives the ultrasonic waves (echoes) reflected at the observation target site, and outputs an electric signal (received signal) according to the reception sensitivity at that time.

[0037] The above series of steps (i.e., supplying a driving voltage, transmitting and receiving ultrasonic waves, and outputting an electrical signal) are repeated by shifting the position of the transducer to be driven among the N ultrasonic transducers 48 one by one (one ultrasonic transducer 48 at a time). To be more specific, the above series of steps starts with the ultrasonic transducer 48 located at one end of the N ultrasonic transducers 48 as the center, and the m transducers to be driven on both sides of the ultrasonic transducer 48. The above series of steps is repeated every time the position of the transducer to be driven is shifted by switching the open channel by the multiplexer 140. Finally, the above series of steps is repeated a total of N times until it reaches the m transducers to be driven on both sides of the ultrasonic transducer 48 located at the other end of the N ultrasonic transducers 48 as the center.

[0038] The backing material layer 54 supports each ultrasonic transducer 48 of the ultrasonic transducer array 50 from the back side. The backing material layer 54 also has a function of attenuating ultrasonic waves emitted from the ultrasonic transducer 48 or ultrasonic waves (echoes) reflected at the observation target area that propagate to the backing material layer 54 side. The backing material is made of a material having rigidity such as hard rubber, and an ultrasonic attenuation material (ferrite, ceramics, etc.) is added as necessary. The acoustic matching layer 74 is overlaid on the ultrasonic transducer array 50, and is provided to match the acoustic impedance between the patient's body and the ultrasonic transducers 48. The provision of the acoustic matching layer 74 makes it possible to increase the transmittance of ultrasonic waves. As the material for the acoustic matching layer 74, various organic materials whose acoustic impedance values ​​are closer to that of the patient's body than the piezoelectric elements of the ultrasonic transducers 48 can be used. Specific examples of the material for the acoustic matching layer 74 include epoxy resin, silicone rubber, polyimide, and polyethylene.

[0039] The acoustic lens 76 superimposed on the acoustic matching layer 74 is for converging the ultrasonic waves emitted from the ultrasonic transducer array 50 toward the observation target area. The acoustic lens 76 is made of, for example, a silicon-based resin (millable type silicon rubber (HTV rubber), liquid silicon rubber (RTV rubber), etc.), a butadiene-based resin, a polyurethane-based resin, etc., and is mixed with a powder of titanium oxide, alumina, silica, etc. as necessary. The FPC 60 is electrically connected to the electrodes of each ultrasonic transducer 48. One end of each of the multiple coaxial cables 56 is wired to the FPC 60. When the ultrasonic endoscope 12 is connected to the ultrasonic processor 14 via the ultrasonic connector 32a, the other end (the side opposite to the FPC 60) of each of the multiple coaxial cables 56 is electrically connected to the ultrasonic processor 14.

[0040] Furthermore, in this embodiment, the ultrasonic endoscope 12 includes an endoscope memory 58 (see FIG. 4). The endoscope memory 58 stores the drive times of the multiple ultrasonic transducers 48 during ultrasonic diagnosis. Strictly speaking, the endoscope memory 58 stores the cumulative drive times of the transducers to be driven among the multiple ultrasonic transducers 48. In this embodiment, the accumulated drive time is the period during which ultrasound diagnosis is performed, that is, the period from when acquisition of ultrasound images (moving images) begins to when it ends (more specifically, the time during which ultrasound diagnosis is performed in live mode), but this is not limited to this, and the accumulated drive time may also be the time during which a drive voltage is supplied to the transducer to be driven.

[0041] When the ultrasonic endoscope 12 is connected to the ultrasonic processor device 14, the CPU 152 of the ultrasonic processor device 14 can access the endoscope memory 58 and read the accumulated drive time stored in the endoscope memory 58. In addition, the CPU 152 of the ultrasonic processor device 14 rewrites the accumulated drive time stored in the endoscope memory 58 to a default value, and updates it to a new accumulated drive time when the accumulated drive time changes as an ultrasonic diagnosis is performed.

[0042] (Endoscopic observation section) The endoscopic observation section 38 is a section provided for acquiring an endoscopic image, and is disposed closer to the base end than the ultrasonic observation section 36 at the tip section 40 of the insertion section 22. As shown in Figs. 2 and 3, the endoscopic observation section 38 is composed of an observation window 82, an objective lens 84, a solid-state image sensor 86, an illumination window 88, a cleaning nozzle 90, a wiring cable 92, and the like. The observation window 82 is attached at an angle to the axial direction (the longitudinal direction of the insertion portion 22) at the tip portion 40 of the insertion portion 22. Light incident from the observation window 82 and reflected by a site adjacent to the observation subject is imaged on the imaging surface of a solid-state imaging element 86 by an objective lens 84.

[0043] The solid-state imaging element 86 photoelectrically converts reflected light from an area adjacent to the observation target, which is transmitted through the observation window 82 and the objective lens 84 and formed on the imaging surface, and outputs an imaging signal. A CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor), or the like can be used as the solid-state imaging element 86. The captured image signal output by the solid-state imaging element 86 is transmitted to the endoscope processor unit 16 by the universal cord 26 via a wiring cable 92 extending from the insertion portion 22 to the operation portion 24.

[0044] The illumination windows 88 are provided on both sides of the observation window 82. An output end of a light guide (not shown) is connected to the illumination window 88. The light guide extends from the insertion section 22 to the operation section 24, and its input end is connected to the light source device 18 connected via the universal cord 26. Illumination light emitted by the light source device 18 travels through the light guide and is irradiated from the illumination window 88 towards an area adjacent to the observation subject. The cleaning nozzle 90 is an ejection hole formed in the tip 40 of the insertion portion 22 for cleaning the surfaces of the observation window 82 and the illumination window 88, and air or cleaning liquid is ejected from the cleaning nozzle 90 toward the observation window 82 and the illumination window 88. In this embodiment, the cleaning liquid ejected from the cleaning nozzle 90 is water, in particular degassed water. However, the cleaning liquid is not particularly limited, and may be other liquids, for example, normal water (non-degassed water).

[0045] (Water tank and suction pump) The water tank 21a is a tank for storing deaerated water, and is connected to the light source connector 32c by an air / water supply tube 34a. The deaerated water is used as a cleaning liquid to be sprayed from the cleaning nozzle 90. The suction pump 21b sucks up the aspirate (including the degassed water supplied for washing) in the body cavity through the treatment tool outlet 44. The suction pump 21b is connected to the light source connector 32c by a suction tube 34b. The ultrasonic diagnostic device 10 may also include an air supply pump that supplies air to a predetermined air supply destination.

[0046] A treatment tool channel 45 and air / water supply pipes (not shown) are provided in the insertion section 22 and the operation section 24. The treatment tool channel 45 connects between the treatment tool insertion port 30 and the treatment tool outlet port 44 provided in the operation unit 24. The treatment tool channel 45 is also connected to the suction button 28b provided in the operation unit 24. The suction button 28b is connected to the treatment tool channel 45 as well as to the suction pump 21b. One end of the air / water supply pipe is connected to the cleaning nozzle 90, and the other end is connected to the air / water supply button 28a provided on the operation unit 24. The air / water supply button 28a is connected to the air / water supply pipe and also to the water supply tank 21a.

[0047] (Operation unit) The operation unit 24 is a part that is operated by the surgeon when starting, during, and ending an ultrasound diagnosis, and one end of the operation unit 24 is connected to one end of a universal cord 26. The operation unit 24 also has an air / water supply button 28a, a suction button 28b, a pair of angle knobs 29, and a treatment tool insertion port (forceps port) 30, as shown in FIG. When each of the pair of angle knobs 29 is rotated, the bending portion 42 is remotely operated and bent. This bending operation makes it possible to orient the tip 40 of the insertion portion 22, on which the ultrasonic observation portion 36 and the endoscopic observation portion 38 are provided, in a desired direction.

[0048] The treatment tool insertion port 30 is a hole formed for inserting a treatment tool (not shown) such as forceps, and is connected to a treatment tool outlet 44 via a treatment tool channel 45. The treatment tool inserted into the treatment tool insertion port 30 passes through the treatment tool channel 45 and is then introduced into the body cavity from the treatment tool outlet 44. The air / water supply button 28a and the suction button 28b are two-stage switchable push buttons, and are operated to switch between opening and closing the channels provided inside the insertion section 22 and the operation section 24, respectively.

[0049] <<Configuration of ultrasonic processor>> The ultrasonic processor 14 causes the ultrasonic transducer unit 46 to transmit and receive ultrasonic waves, and generates an ultrasonic image by imaging a reception signal output from the ultrasonic transducer 48 (specifically, a driven element) when receiving ultrasonic waves. The ultrasonic processor 14 also displays the generated ultrasonic image on the monitor 20. Furthermore, in this embodiment, the ultrasonic processor device 14 polarizes the transducers to be polarized by supplying a polarization voltage to the transducers to be polarized among the N ultrasonic transducers 48. By performing this polarization process, the ultrasonic transducers 48 that have been depolarized by repeated ultrasonic diagnosis can be polarized again, and this makes it possible to restore the ultrasonic reception sensitivity of the ultrasonic transducers 48 to a good level.

[0050] As shown in FIG. 4, the ultrasound processor device 14 has a multiplexer 140, a receiving circuit 142, a transmitting circuit 144, an A / D converter 146, an ASIC (Application Specific Integrated Circuit) 148, a cine memory 150, a trigger generating circuit 156, a CPU (Central Processing Unit) 152, and a DSC (Digital Scan Converter) 154. The receiving circuit 142 and the transmitting circuit 144 are electrically connected to the ultrasonic transducer array 50 of the ultrasonic endoscope 12. The multiplexer 140 selects up to m transducers to be driven from the N ultrasonic transducers 48, and opens the channels thereof.

[0051] The transmission circuit 144 includes an FPGA (field programmable gate array), a pulser (pulse generating circuit 158), a SW (switch), etc., and is connected to the MUX (multiplexer 140). Note that an ASIC (application specific integrated circuit) may be used instead of the FPGA. The transmission circuit 144 is a circuit that supplies a drive voltage for transmitting ultrasonic waves to the transducer to be driven selected by the multiplexer 140 in accordance with a control signal sent from the CPU 152 in order to transmit ultrasonic waves from the ultrasonic transducer unit 46. The drive voltage is a pulsed voltage signal (transmission signal) and is applied to the electrodes of the transducer to be driven via the universal cord 26 and the coaxial cable 56. The transmission circuit 144 has a pulse generating circuit 158 ​​that generates a transmission signal based on a control signal, and under the control of the CPU 152, the pulse generating circuit 158 ​​is used to generate a transmission signal that drives the multiple ultrasonic transducers 48 to generate ultrasonic waves, and the transmission signal is supplied to the multiple ultrasonic transducers 48. When performing ultrasonic diagnosis under the control of the CPU 152, the transmission circuit 144 generates a first transmission signal having a drive voltage for performing ultrasonic diagnosis using the pulse generation circuit 158. When performing polarization processing under the control of the CPU 152, the transmission circuit 144 generates a second transmission signal having a polarization voltage for performing polarization processing using the same pulse generation circuit 158 ​​as that used for generating the first transmission signal.

[0052] The receiving circuit 142 is a circuit that receives an electrical signal output from the transducer to be driven that has received an ultrasonic wave (echo), i.e., a received signal. The receiving circuit 142 also amplifies the received signal received from the ultrasonic transducer 48 in accordance with a control signal sent from the CPU 152, and passes the amplified signal to the A / D converter 146. The A / D converter 146 is connected to the receiving circuit 142, converts the received signal received from the receiving circuit 142 from an analog signal to a digital signal, and outputs the converted digital signal to the ASIC 148.

[0053] The ASIC 148 is connected to the A / D converter 146, and constitutes a phase matching unit 160, a B mode image generating unit 162, a PW mode image generating unit 164, a CF mode image generating unit 166, and a memory controller 151, as shown in FIG. In this embodiment, the above-mentioned functions (specifically, the phase matching unit 160, the B-mode image generating unit 162, the PW-mode image generating unit 164, the CF-mode image generating unit 166, and the memory controller 151) are realized by a hardware circuit such as the ASIC 148, but the present invention is not limited to this. The above-mentioned functions may be realized by cooperation between a central processing unit (CPU) and software (computer program) for executing various data processing. The phase matching unit 160 performs a process of delaying and adding (matching the phase of the received data and then adding) the received signal (received data) digitized by the A / D converter 146. The phase matching process generates a sound ray signal with a narrowed focus of the ultrasonic echo.

[0054] The B-mode image generating unit 162, the PW-mode image generating unit 164, and the CF-mode image generating unit 166 generate ultrasound images based on electrical signals (strictly speaking, audio signals generated by phasing and adding the received data) output by the transducers to be driven among the multiple ultrasonic transducers 48 when the ultrasonic transducer unit 46 receives ultrasound. The B-mode image generating unit 162 is an image generating unit that generates a B-mode image, which is a tomographic image of the inside (body cavity) of a patient. The B-mode image generating unit 162 corrects the attenuation caused by the propagation distance according to the depth of the reflection position of the ultrasonic waves by STC (Sensitivity Time gain Control) for the sequentially generated sound ray signals. In addition, the B-mode image generating unit 162 performs envelope detection processing and Log (logarithmic) compression processing on the corrected sound ray signals to generate a B-mode image (image signal).

[0055] The PW mode image generating unit 164 is an image generating unit that generates an image that displays the velocity of blood flow in a predetermined direction. The PW mode image generating unit 164 extracts frequency components by performing a fast Fourier transform on a plurality of sound ray signals in the same direction among the sound ray signals sequentially generated by the phase matching unit 160. Thereafter, the PW mode image generating unit 164 calculates the velocity of blood flow from the extracted frequency components, and generates a PW mode image (image signal) that displays the calculated blood flow velocity. The CF mode image generating unit 166 is an image generating unit that generates an image that displays information about blood flow in a predetermined direction. The CF mode image generating unit 166 generates an image signal that indicates information about blood flow by calculating the autocorrelation of a plurality of sound ray signals in the same direction among the sound ray signals that are sequentially generated by the phase matching unit 160. Thereafter, the CF mode image generating unit 166 generates a CF mode image (image signal) as a color image in which information about blood flow is superimposed on the B mode image signal generated by the B mode image generating unit 162 based on the above image signal.

[0056] The memory controller 151 stores the image signals generated by the B mode image generator 162 , the PW mode image generator 164 , or the CF mode image generator 166 in the cine memory 150 . The DSC 154 is connected to the ASIC 148, and converts (raster converts) the image signal generated by the B mode image generation unit 162, the PW mode image generation unit 164, or the CF mode image generation unit 166 into an image signal that conforms to the scanning method of a normal television signal, and outputs the image signal to the monitor 20 after performing various necessary image processing such as gradation processing.

[0057] The cine memory 150 has a capacity for storing image signals for one frame or several frames. The image signals generated by the ASIC 148 are output to the DSC 154 and are also stored in the cine memory 150 by the memory controller 151. In the freeze mode, the memory controller 151 reads out the image signals stored in the cine memory 150 and outputs them to the DSC 154. As a result, an ultrasound image (still image) based on the image signals read out from the cine memory 150 is displayed on the monitor 20. A trigger generating circuit 156 generates a trigger for starting a polarization process in the CPU 152. The cause of the generation of the trigger will be described later.

[0058] The CPU 152 functions as a control unit (control circuit) that controls each part of the ultrasonic processor 14, and is connected to the receiving circuit 142, the transmitting circuit 144, the A / D converter 146, and the ASIC 148 to control these devices. More specifically, the CPU 152 is connected to the console 100, and controls each part of the ultrasonic processor 14 according to the examination information, control parameters, etc. inputted through the console 100. Furthermore, when the ultrasonic endoscope 12 is connected to the ultrasonic processor device 14 via the ultrasonic connector 32a, the CPU 152 automatically recognizes the ultrasonic endoscope 12 using a method such as PnP (Plug and Play). After that, the CPU 152 accesses the endoscope side memory 58 of the ultrasonic endoscope 12 and reads the accumulated drive time stored in the endoscope side memory 58.

[0059] Furthermore, when an ultrasound diagnosis is completed, the CPU 152 accesses the endoscope side memory 58 and updates the accumulated drive time stored in the endoscope side memory 58 to a value obtained by adding the time required for the ultrasound diagnosis performed immediately before. In this embodiment, the cumulative operating time is stored in the ultrasonic endoscope 12, but this is not limited to this, and the cumulative operating time may be stored for each ultrasonic endoscope 12 on the ultrasonic processor device 14 side.

[0060] The CPU 152 is also connected to a trigger generating circuit 156, and when a trigger is given from the trigger generating circuit 156, during the implementation period of the ultrasonic diagnosis, the CPU 152 controls the transmission circuit 144 (pulse generating circuit 158) during the non-diagnostic period within each frame time to generate a polarization drive pulse, which is a pulsed drive voltage, and supplies the drive pulse to each of the ultrasonic transducers 48 of the ultrasonic transducer array 50 to perform polarization processing of each ultrasonic transducer 48. More specifically, after the trigger is given from the trigger generating circuit 156, during the implementation period of the ultrasonic diagnosis, during the non-diagnostic period during which the transmission of ultrasonic waves for performing the ultrasonic diagnosis and the reception of reflected waves are not performed, which is a period other than the period during which the image of each frame is acquired among each frame time during which the image of each frame (still image) of the ultrasonic image (moving image) is acquired.

[0061] In the present invention, the polarization drive pulse is generated by a transmission circuit 144 that generates a diagnostic drive pulse for acquiring an ultrasonic image. That is, the transmission circuit 144 has the same circuit configuration as an existing transmission circuit that does not have a new circuit configuration for generating a polarization drive pulse. Here, the transmission circuit 144 has a settable voltage range in which at least two drive voltages, an image drive voltage of the diagnostic drive pulse and a polarization drive voltage of the polarization drive pulse, can be set. When acquiring an ultrasonic image, the image drive voltage is set within the settable voltage range, and when performing a polarization process, the polarization drive voltage is set to a different voltage from the image drive voltage within the same settable voltage range. In the present invention, the polarization drive voltage is preferably set to a voltage higher than the image drive voltage, more preferably set to a higher voltage within the settable voltage range, and most preferably set to the upper limit voltage.

[0062] In addition, although details will be described later, the polarization driving pulse (main lobe) is a driving pulse in a frequency band different from the probe frequency band of the diagnostic driving pulse. Therefore, it can be said that the drive voltage applied to the ultrasonic transducer 48 during the polarization process is different from and higher than the drive voltage applied to the ultrasonic transducer 48 when an ultrasonic image is acquired. Also, it can be said that the polarization drive pulse wave applied to the ultrasonic transducer 48 during the polarization process is generated by the same transmission circuit 144 as the diagnostic drive pulse wave applied to the ultrasonic transducer 48 when an ultrasonic image is acquired, is a different polarization drive voltage within the same settable voltage range as the image drive pulse wave, and is a drive pulse with a frequency different from the probe frequency band for acquiring an ultrasonic image. From the above, the present invention has an existing transmission circuit configuration, and uses a transmission circuit 144 for outputting the same drive pulse as used to acquire an ultrasonic image, to output a polarization drive pulse having a drive voltage within the same settable voltage range as the diagnostic drive pulse for acquiring an ultrasonic image, and a frequency different from the probe frequency band, thereby performing polarization processing of the ultrasonic transducer 48 of the ultrasonic endoscope 12 at a time different from the time when the ultrasonic image is acquired.

[0063] The magnitude (voltage value or potential) of the driving voltage of the polarization driving pulse is set by the CPU 152 to an appropriate value that satisfies the condition for obtaining the repolarization effect, within the settable voltage range of the transmission circuit 144, according to the specifications (more specifically, the thickness and material of the ultrasonic transducer 48) of the ultrasonic endoscope 12 connected to the ultrasonic processor device 14. The supply time of the driving voltage of the polarization driving pulse is set by the CPU 152 to an appropriate value that satisfies the condition for obtaining the repolarization effect, according to the specifications (more specifically, the thickness and material of the ultrasonic transducer 48) of the ultrasonic transducer 48. Thereafter, the CPU 152 performs polarization processing based on the above set values.

[0064] That is, in the present invention, when an ultrasound image is to be acquired, the CPU (control circuit) 152 controls the transmission circuit 144 (pulse generating circuit 158) to generate diagnostic drive pulses (transmission signals) to be applied to each of the multiple ultrasound transducers 48 that generate ultrasound waves to acquire the ultrasound image. On the other hand, when performing polarization processing, the CPU (control circuit) 152 controls the transmission circuit to generate a polarization driving pulse having a different polarization driving voltage within the same settable voltage range as the diagnostic driving pulse and a frequency different from the probe frequency band of the ultrasonic probe (ultrasonic transducer unit 46) for acquiring an ultrasonic image, in order to perform polarization processing of multiple ultrasonic transducers 48. As a result, in the present invention, when a polarization process is performed, a polarization drive pulse is applied to the plurality of ultrasonic transducers 48, and the polarization process of the plurality of ultrasonic transducers 48 is performed by the polarization drive pulse.

[0065] Next, a description will be given of the drive waveform (transmission waveform) and pulse waveform of the polarization drive pulse (polarization transmission wave) transmitted from the transmission circuit 144 to the ultrasonic transducer 48 in the present invention. 5A and 5B are graphs showing an example of a driving waveform of a polarization driving pulse transmitted from the transmission circuit shown in Fig. 4, and a graph showing the relationship between the sensitivity and frequency of the driving waveform. The driving waveform shown in Fig. 5A is a single unipolar wave waveform with a frequency of 1.25 MHz. In the present invention, the driving waveform of the polarization driving pulse is not particularly limited, but it is preferable to perform the polarization process of the ultrasonic transducer 48 using a polarization driving pulse having a driving waveform with a unipolar waveform shown in Fig. 5A and a frequency characteristic shown by a solid line in Fig. 5B. In the example shown in Fig. 5B, for example, at a sensitivity level of -20 dB or more, the probe frequency band for acquiring an ultrasonic image is about 2.7 MHz to about 11.7 MHz as shown by a dashed line, whereas the band of the main lobe of the driving waveform of the polarization driving pulse shown by a solid line is about 2.3 MHz or less. That is, the frequency band characteristic of the polarization driving pulse and the frequency band characteristic of the diagnostic driving pulse do not overlap at a sensitivity level of -20 dB or more.

[0066] That is, in the present invention, as shown in FIG. 5B, in the drive waveform of the polarization drive pulse, it is preferable that the frequency band of the main lobe and the probe frequency band shown by the dashed line do not overlap at a sensitivity level of -20 dB or more. Also, it is preferable that the frequency band of the main lobe is lower than the probe frequency band at a sensitivity level of -20 dB or more. The reason for this is that in the polarization process, it is necessary to prevent excess ultrasonic output to reduce the influence on the ultrasonic image, prevent a temperature rise, and reduce the influence on the body cavity of the subject due to the temperature rise. In particular, the upper limit temperature of the tip part of the ultrasonic endoscope 12 inserted into the body cavity of the subject is strictly limited so as not to affect the body cavity, and it is necessary to prevent a temperature rise.

[0067] In the present invention, the polarization driving pulse (main lobe) is transmitted outside the probe frequency band, so the energy input to the ultrasonic transducer 48 is small, and the temperature rise is suppressed. In addition, since the frequency outside the probe frequency band is outside the resonance band in which the ultrasonic transducer 48 resonates, even if the polarization driving pulse (main lobe) is applied to the ultrasonic transducer 48, the output sound pressure is also small. In the drive waveform of the polarization drive pulse shown in Fig. 5B, in addition to the main lobe, one or more side lobes, also shown by solid lines, are generated accompanying the main lobe within the probe frequency band, four side lobes in the example shown in Fig. 5B. As shown in Fig. 5B, the maximum sensitivity of all of these side lobes within the probe frequency band is preferably -10 dB or less, and the average sensitivity of these side lobes is preferably -20 dB or less. The reason for this is as follows. Generally, the specifications of the frequency characteristics of a probe are expressed in the -20dB band of the transmitting and receiving sensitivity. This is because it is determined that signals below 1 / 10 of the peak sensitivity have almost no effect on the image. On the other hand, unlike a probe, the band of the transmitting wave is only the transmitting portion, so the threshold level is 20dB / 2=10dB. Therefore, when considering the transmitting component, -10dB is more preferable.

[0068] In addition, in the present invention, the driving waveform of the polarization driving pulse is not particularly limited and may be a bipolar waveform as shown in Fig. 6A, but is preferably a unipolar waveform as shown in Fig. 5A. The reason for this is that, as shown in the frequency characteristics of the driving waveform in Fig. 6B, the sensitivity of the main lobe is the same whether it is a unipolar waveform shown by a solid line or a bipolar waveform shown by a dashed dotted line, but the sensitivity of each of the four side lobes is lower in the unipolar waveform than in the bipolar waveform. Therefore, by making the transmission waveform a unipolar waveform as shown in FIG. 5A, not only the main lobe but also the harmonic components are suppressed, and a greater effect can be expected.

[0069] Also, as shown in Fig. 7A, a plurality of unipolar waveforms, two pulse waves in the example shown in Fig. 7A, may be transmitted as the polarization drive pulse. The polarization drive pulse shown in Fig. 7A has a drive waveform including two pulse waves of the drive waveform of the polarization drive pulse shown in Fig. 5A. The frequency characteristics of the drive waveform of the polarization drive pulse shown in Fig. 7A are shown in Fig. 7B. The frequency characteristics of the drive waveform shown in Fig. 7B differ from the frequency characteristics of the drive waveform shown in Fig. 5B in the waveform of the main lobe, but there is not much change in the waveform of the side lobe. Also, as shown in Fig. 7C, it is preferable to transmit a polarization driving pulse in which a plurality of unipolar pulse waveforms are connected together, with a minimum number of clocks between each of the unipolar driving pulses. That is, in the present invention, it is preferable that the transmission circuit 144 outputs a plurality of unipolar waveforms as the polarization driving pulse, with a minimum number of clocks between each of the unipolar waveforms defined in the ultrasonic processor 14. The reason for this is that, although it is optimal to apply a DC voltage for polarization processing, when using a transmission circuit 144 having a conventional transmission circuit configuration as in the present invention, a DC voltage cannot be transmitted.

[0070] The minimum and maximum time widths are determined by the type of pulser (pulse generating circuit 158) of the transmission circuit 144 of the ultrasonic processor device 14 used in the ultrasonic diagnostic device 10. For this reason, a high repolarization effect can be expected by using the time of the minimum number of clocks specified in the transmission circuit 144 as the minimum time width, sandwiching the minimum time width between multiple unipolar waveforms, and making the polarization processing waveform close to a DC voltage. The minimum time width of the two unipolar pulse waveforms, that is, the maximum pulse width, is determined by the specifications of the pulser (pulse generating circuit 158) of the transmission circuit 144. Control to comply with this specification is output from the above-mentioned FPGA in the transmission circuit 144. Furthermore, by using a combination of multiple unipolar waveforms shown in FIG. 7C as the driving waveform of the polarization driving pulse, as shown by the two-dot chain line in FIG. 7D, the maximum sensitivity of the side lobe can be reduced more than in the case of a driving waveform of the polarization driving pulse consisting of a single unipolar waveform as shown by the solid line in FIG. 7D. In contrast, Figures 8A and 8B are graphs showing an example of the driving waveform of the diagnostic driving pulse transmitted from the transmission circuit shown in Figure 4, and a graph showing the relationship between the sensitivity and frequency of the driving waveform. The driving waveform shown in Figure 8A is a bipolar single wave waveform with a center frequency of 6 MHz. The frequency characteristic of the driving waveform of the diagnostic driving pulse is shown in Figure 8B.

[0071] <<Examples of ultrasound diagnostic equipment operation>> Next, as an example of the operation of the ultrasonic diagnostic device 10, a flow of a series of processes related to ultrasonic diagnosis (hereinafter also referred to as diagnostic processing) will be described with reference to Figs. 9 to 11. Fig. 9 is a diagram showing the flow of diagnostic processing using the ultrasonic diagnostic device 10. Fig. 10 is a diagram showing the procedure of diagnostic steps during diagnostic processing. Fig. 11 is a diagram showing the flow of processing when polarization processing is performed in the diagnostic step.

[0072] When the power of each part of the ultrasonic diagnostic apparatus 10 is turned on while the ultrasonic endoscope 12 is connected to the ultrasonic processor 14, the endoscope processor 16, and the light source device 18, this triggers the start of diagnostic processing. In the diagnostic processing, an input step is first performed (S001) as shown in Fig. 9. In the input step, the operator inputs examination information, control parameters, etc. through the console 100. After the input step is completed, a standby step is performed until an instruction to start diagnosis is given (S002). Using this standby step, the CPU 152 of the ultrasonic processor 14 reads the accumulated drive time from the endoscope side memory 58 of the ultrasonic endoscope 12 (S003).

[0073] Next, when the operator issues a diagnosis start command (Yes in S004), the CPU 152 controls each part of the ultrasonic processor device 14 to execute the diagnosis step (S005). The diagnosis step proceeds according to the flow shown in FIG. 10. If the designated image generation mode is the B mode (Yes in S031), the CPU 152 controls each part of the ultrasonic processor device 14 to generate a B mode image (S032). If the designated image generation mode is not the B mode (No in S031) but the CF mode (Yes in S033), the CPU 152 controls each part of the ultrasonic processor device 14 to generate a CF mode image (S034). If the designated image generation mode is not the CF mode (No in S033) but the PW mode (Yes in S035), the CPU 152 controls each part of the ultrasonic processor device 14 to generate a PW mode image (S036). If the designated image generation mode is not the PW mode (No in S036), the CPU 152 proceeds to step S037.

[0074] In each image generation mode, as shown in FIG. 11, a trigger for starting the polarization process is generated by the trigger generating circuit 156 and is applied from the trigger generating circuit 156 to the CPU 152 (S041). The CPU 152 determines whether or not a trigger has been given from the trigger generating circuit 156 (S042). If no trigger is given to the CPU 152 (No in S042), the CPU 152 controls each part of the ultrasonic processor device 14 so that a normal ultrasonic diagnosis is performed. In other words, the polarization process is not performed during the implementation of the ultrasonic diagnosis (S043). On the other hand, when a trigger is given to the CPU 152 (Yes in S042), the CPU 152 controls each part of the ultrasonic processor device 14 to perform polarization processing on the multiple ultrasonic transducers 48 during a non-diagnostic period during which ultrasonic waves for performing ultrasonic diagnosis are not transmitted and reflected waves are not received, which is a period other than the period during which each frame image of an ultrasonic image is acquired during the implementation of ultrasonic diagnosis after the trigger is given, during which ultrasonic diagnosis is performed. In other words, polarization processing is performed during the implementation of ultrasonic diagnosis (S044).

[0075] 10, the CPU 152 judges whether the ultrasound diagnosis has been completed (S037). If the ultrasound diagnosis has not been completed (No in S037), the process returns to the diagnosis step S031, and the generation of ultrasound images in each image generation mode is repeatedly performed until a diagnosis end condition is satisfied. An example of the diagnosis end condition is that the operator issues an instruction to end the diagnosis via the console 100.

[0076] On the other hand, when the diagnosis end condition is met and the ultrasound diagnosis ends (Yes in S037), the CPU 152 adds the time required for the ultrasound diagnosis that has been performed up to that point to the accumulated drive time read from the endoscope memory 58 in step S003, and updates the accumulated drive time stored in the endoscope memory 58 to the accumulated drive time after the addition (S038). The diagnosis step ends when the series of steps in the diagnosis step (S031 to S038) described above are completed. 9, when the power of each part of the ultrasound diagnostic device 10 is turned off (Yes in S006), the diagnostic process ends. On the other hand, when the power of each part of the ultrasound diagnostic device 10 is kept on (No in S006), the process returns to the input step S001, and each step of the diagnostic process described above is repeated.

[0077] Next, the timing of scanning the scan lines by electronic sector scanning when performing ultrasonic diagnosis will be described. Fig. 12 is a conceptual diagram showing an example of the scan timing of a plurality of scanning lines scanned by electronic sector scanning during an ultrasonic diagnosis period. In Fig. 12, the vertical axis shows the voltage of a pulse (transmission pulse) of a transmission signal that generates ultrasonic waves for scanning the scanning lines, and the horizontal axis shows the passage of time.

[0078] In this embodiment, the total number (number of elements) of the multiple ultrasonic transducers 48 is N=128, and the total number of scanning lines (lines) in each frame time during which an image (still image) of each frame of an ultrasonic image (moving image) is acquired is 128, from scanning line Line 1 on the right end side to scanning line Line 128 on the left end side, as shown in Fig. 13. In addition, the number of ultrasonic transducers 48 (number of aperture channels) simultaneously driven to form an ultrasonic beam during ultrasonic diagnosis is m=64. The multiple scanning lines Line 1 to Line 128 are scanned by electronic sector scanning to acquire one frame of an ultrasound image, and the ultrasound beams for scanning the image of each line of the ultrasound image are represented as virtual lines.

[0079] When performing ultrasonic diagnosis, as shown in Fig. 12, during the period during which ultrasonic diagnosis is performed, that is, from the start to the end of acquisition of ultrasonic images (moving images), scanning of scanning lines Line1 to Line128 is performed sequentially within each frame time during which each frame image of an ultrasonic image is acquired. That is, a transmission signal (first transmission signal) having a drive voltage for performing ultrasonic diagnosis is supplied from the transmission circuit 144 to a transducer to be driven for performing ultrasonic diagnosis. Within each frame time, the period during which an ultrasound image is acquired is the period during which scanning is performed on scan lines Line 1 to Line 128. In addition, the non-diagnostic period is the period from the end of scanning on scan line Line 128 to the end of each frame time.

[0080] 12, a non-diagnostic period is provided during which no ultrasonic waves are transmitted for ultrasonic diagnosis and no reflected waves (echoes) of ultrasonic waves are received between the end of scanning the last scanning line, Line128, in one frame time and the start of scanning the first scanning line, Line1, in the next frame time. Note that, although a non-diagnostic period is provided in this embodiment, some systems do not provide a non-diagnostic period.

[0081] Next, the timing of supplying a transmission signal for performing polarization processing when the polarization processing is performed during the implementation of ultrasonic diagnosis will be described. FIG. 14 is a conceptual diagram showing an example of the timing of scanning the scan lines and the timing of supplying a transmission signal for performing the polarization process when the polarization process is performed during an ultrasonic diagnosis. When performing the polarization process, as shown in Fig. 14, scanning of the scanning lines Line1 to Line128 for performing ultrasonic diagnosis is performed sequentially within each frame time in the same manner as in Fig. 12. Then, in each frame time, the polarization process is performed in a non-diagnostic period after the scanning of the last scanning line Line128 is completed. That is, a transmission signal (second transmission signal) having a polarization voltage for performing the polarization process is supplied from the transmission circuit 144 to the transducer to be polarized for performing the polarization process.

[0082] In the present embodiment, as transmission signals for performing polarization processing, transmission signals for two polarization processings, polarization processing 1 and 2, are supplied. As described above, the total number of the ultrasonic transducers 48 is 128, and the number of aperture channels is half of that, 64. Accordingly, a transmission signal for polarization processing 1 is supplied to 64 ultrasonic transducers 48, which is half of the 128 ultrasonic transducers 48, and then a transmission signal for polarization processing 2 is supplied to the remaining half, 64 ultrasonic transducers 48. As described above, the transmission signals for the two polarization processes, polarization process 1 and 2, are polarization drive pulses having the drive waveforms shown in Fig. 5 to Fig. 8. Therefore, a description of the polarization drive pulses of these transmission signals will be omitted here.

[0083] In the present embodiment, a non-diagnostic period is provided within each frame time, and by supplying a transmission signal for performing polarization processing within this non-diagnostic period, it is possible to perform polarization processing without reducing the frame rate. The polarization process can be performed during a period other than the period during which an ultrasonic image is acquired, that is, before the first scanning line Line1 is scanned and after the last scanning line Line128 is scanned. On the other hand, if a non-diagnostic period is not provided within each frame time, a transmission signal for polarization processing may be supplied by intentionally lowering the frame rate within a range that does not affect the image quality of the ultrasound image. This is because it is considered that a temporary deterioration in image quality (part of the moving image) due to a lowered frame rate is more acceptable than a deterioration in image quality of the entire image (all of the moving image) due to a decrease in the reception sensitivity of the ultrasound transducer 48.

[0084] Alternatively, by reducing at least one of the line density, number of lines, and line spacing of multiple scanning lines scanned by electronic sector scanning for performing ultrasound diagnosis, it is possible to generate non-diagnostic periods during the period in which ultrasound diagnosis is performed within each frame time, during which ultrasound for performing ultrasound diagnosis is not transmitted and reflected waves are not received, and to perform polarization processing within the generated non-diagnostic periods while maintaining the frame rate. Here, line density refers to the ratio of the number of scanning lines scanned in one frame time to the total number of scanning lines in one frame time. The number of lines refers to the number of scanning lines scanned in one frame time out of the multiple scanning lines in one frame time. The line interval refers to the time interval from when one scanning line out of the multiple scanning lines in one frame time is scanned to when the next scanning line is scanned.

[0085] FIG. 15 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the line density of scanning lines for performing ultrasonic diagnosis is reduced. In this case, as shown in Fig. 15, within each frame time, the scanning of the even-numbered 64 scanning lines, Line2, Line4, ..., Line128, is omitted, and only the odd-numbered 64 scanning lines, Line1, Line3, ..., Line127, are sequentially scanned. Then, within each frame time, after the scanning of the last scanning line, Line127, is completed, the polarization process is performed in the non-diagnosis period generated by omitting the scanning of the even-numbered 64 scanning lines, Line2, Line4, ..., Line128, in the same manner as in Fig. 14. In this way, by reducing the line density of the scan lines for performing ultrasonic diagnosis, a non-diagnostic period can be generated within each frame time, so that polarization processing can be performed within the generated non-diagnostic period while maintaining the frame rate.

[0086] In addition, the scanning of the odd-numbered 64 scanning lines, Line1, Line3, ..., Line127, may be omitted, and only the even-numbered 64 scanning lines, Line2, Line4, ..., Line128, may be scanned. In addition, after scanning one or more scanning lines, the scanning of the next one may be omitted, for example, after scanning two scanning lines, the scanning of the next one may be omitted. When reducing the line density of the scanning lines, the rate at which the line density of the scanning lines is reduced may be appropriately determined depending on the image quality of the ultrasound image, the time required to perform the polarization process, and the like.

[0087] Next, FIG. 16 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the number of scanning lines for performing ultrasonic diagnosis is reduced. In this case, as shown in Fig. 16, in each frame time, the scanning of nine scanning lines Line1 to Line9 on the right end side and ten scanning lines Line119 to Line128 on the left end side are omitted, and the scanning of 109 scanning lines Line10 to Line118 in the center is performed sequentially. Then, after the scanning of the last scanning line Line118 is completed in each frame time, the polarization process is performed in the same manner as in Fig. 14 in the non-diagnosis period generated by omitting the scanning of the scanning lines Line1 to Line9 and the scanning lines Line119 to Line128.

[0088] In this way, by reducing the number of scan lines used for ultrasonic diagnosis, a non-diagnostic period can be generated within each frame time, so that polarization processing can be performed within the generated non-diagnostic period while maintaining the frame rate. In addition, it is not essential to omit scanning of the scanning lines at both ends within each frame time, and scanning of only one end may be omitted. When reducing the number of scanning lines, the number of scanning lines to be reduced can be appropriately determined depending on the time required for performing the polarization process, etc. When reducing the number of scanning lines, it is more preferable to omit scanning of scanning lines sequentially from the end side rather than omitting scanning of scanning lines in the center in order to prevent deterioration of the image quality of the ultrasound image.

[0089] Next, FIG. 17 is a conceptual diagram showing an example of timing for supplying a transmission signal for performing polarization processing when the line spacing of scanning lines for performing ultrasonic diagnosis is reduced. In this case, as shown from the state shown in the upper side to the state shown in the lower side of Fig. 17, the line interval (time interval between two adjacent scanning lines) of the scanning lines Line1 to Line128 is reduced (narrowed) within each frame time, and scanning of the scanning lines Line1 to Line128 is performed sequentially. Then, after the scanning of the last scanning line Line128 within each frame time is completed, polarization processing is performed in the non-diagnosis period generated by reducing the line interval of the scanning lines Line1 to Line128 in the same manner as in Fig. 14.

[0090] The line spacing of the scanning lines is generally determined by the time from transmitting the ultrasonic wave to receiving the reflected wave, etc. If the line spacing of the scanning lines is reduced too much, it may have a negative effect on the acquired ultrasonic image, but usually, the line spacing of the scanning lines is provided with a margin time in addition to the time from transmitting the ultrasonic wave to receiving the reflected wave. Therefore, if it is within the range of this margin time, it is possible to reduce the line spacing of the scanning lines without degrading the image quality of the ultrasonic image. In this way, by reducing the line spacing of the scanning lines used for ultrasonic diagnosis, a non-diagnostic period can be generated within each frame time, so that polarization processing can be performed within the generated non-diagnostic period while maintaining the frame rate.

[0091] In addition, when reducing the line spacing between scanning lines within each frame time, the time for reducing the line spacing between scanning lines can be appropriately determined depending on the time required to perform the polarization process, etc., within the range in which the line spacing between scanning lines can be reduced. In addition, when performing ultrasonic diagnosis, the ultrasonic transducer 48 arranged in the center is driven more times than the end portion, so that the ultrasonic transducer 48 arranged in the center is at a higher risk of depolarization than the end portion.

[0092] In the present embodiment, since the number of aperture channels is 64, when scanning the central scanning line Line64, a total of 64 ultrasonic transducers 48 are simultaneously driven, including 64 ultrasonic transducers 48 on both sides of the central ultrasonic transducer 48, for example, 32 ultrasonic transducers 48 on the left end side from the central ultrasonic transducer 48, and 32 ultrasonic transducers 48 on the right end side from the ultrasonic transducer 48 one to the right of the central ultrasonic transducer 48. The same applies when scanning the other central scanning lines Line33 to Line96. In contrast, when scanning the scanning line Line 1 at the right end, the number of aperture channels is 64, but since there is no ultrasonic transducer 48 to the right of the ultrasonic transducer 48 at the right end, only the 32 ultrasonic transducers 48 from the ultrasonic transducer 48 at the right end to the central side are driven simultaneously.

[0093] Furthermore, when scanning the second scanning line from the right end, only one ultrasonic transducer 48, the right end ultrasonic transducer 48, is present to the right of the second ultrasonic transducer 48 from the right end, so only a total of 33 ultrasonic transducers 48, including the second ultrasonic transducer 48 from the right end to the 32 ultrasonic transducers 48 toward the center and the one ultrasonic transducer 48 at the right end, are driven simultaneously. The same applies when scanning the third to 32nd scanning lines Line3 to Line32 from the right end, and a total of 34 to 63 ultrasonic transducers 48 are driven simultaneously, respectively. The same applies when scanning the scanning lines Line97 to Line128 on the left end side. Therefore, it is desirable to make the time for performing the polarization process longer for the ultrasonic transducers 48 arranged in the center than for both ends within each frame time.

[0094] Next, a description will be given of the timing for supplying a transmission signal to extend the time for which the polarization process is performed on the ultrasonic transducers 48 arranged in the center rather than on both ends when the polarization process is performed during an ultrasonic diagnosis. FIG. 18 is a conceptual diagram showing an example of the timing of supplying a transmission signal for extending the time for performing polarization processing on an ultrasonic transducer located in the center rather than at either end when performing polarization processing during an ultrasonic diagnosis. In this case, as shown in Fig. 18, in each frame time, scanning of the scanning lines Line1 to Line128 for performing ultrasonic diagnosis is performed sequentially in the same manner as in Fig. 12. Then, in each frame time, in the non-diagnostic period after the scanning of the last scanning line Line128 is completed, as shown in Fig. 19, polarization processing is performed separately for the 64 ultrasonic transducers 48 in the center and the 64 ultrasonic transducers 48 at both ends, including the 32 at the right end and the 32 at the left end.

[0095] In the present embodiment, three transmission signals, polarization processes 1 to 3, are supplied as transmission signals for performing polarization processes. Of the 128 ultrasonic transducers 48, a transmission signal for polarization process 1 is supplied to a total of 64 ultrasonic transducers 48 including the 32 ultrasonic transducers 48 at the right end and the 32 ultrasonic transducers 48 at the left end, and then transmission signals for polarization processes 2 and 3 are supplied to the 64 ultrasonic transducers 48 in the center. That is, in each frame time, one polarization process is performed on the 64 ultrasonic transducers 48 at both ends, whereas two polarization processes are performed on the 64 ultrasonic transducers 48 at the center. This allows the 64 ultrasonic transducers 48 at the center, which have a higher risk of depolarization than the 64 ultrasonic transducers 48 at both ends, to undergo polarization process for twice as long as the 64 ultrasonic transducers 48 at both ends. It should be noted that it is sufficient to perform the polarization process for the ultrasonic transducers 48 arranged in the center longer than for the ultrasonic transducers 48 arranged at both ends. For example, the polarization process for the 64 ultrasonic transducers 48 in the center may be performed for more than twice as long as that for the 64 ultrasonic transducers 48 at both ends.

[0096] Next, the timing of generating a trigger, that is, the timing of starting the polarization process, will be described. The ultrasonic transducer 48 reduces the dipoles applied to both sides of the ultrasonic transducer 48 and progresses depolarization depending on the time it takes to transmit ultrasonic waves for ultrasonic diagnosis and receive the reflected waves, i.e., the cumulative drive time of the multiple ultrasonic transducers 48. Since the trigger generating circuit 156 cannot directly determine whether the ultrasonic transducer 48 is depolarized or not, it can determine whether the ultrasonic transducer 48 is depolarized or not based on, for example, the cumulative drive time of the ultrasonic transducer 48 described above, and generate a trigger when the cumulative drive time of multiple ultrasonic transducers 48 for performing ultrasonic diagnosis exceeds a specified time. The specified time may be a default time set in the trigger generating circuit 156, or may be set to an arbitrary time by a user instruction. The specified time is an arbitrary time, and may be on the order of several hours or several frame times.

[0097] Furthermore, the trigger generating circuit 156 can generate a trigger when a button for instructing the start of polarization processing is pressed by a user, which means that the polarization processing can be started at any timing by a user instruction. The button may be an electronic button displayed on the touch panel of the console 100 , or a mechanical button provided on the operation unit 24 of the ultrasonic endoscope 12 . In addition, the trigger generating circuit 156 can generate a trigger when the ultrasound image generation mode is set to a contrast mode in which a contrast image acquired using a contrast agent is highlighted. In the contrast mode, the ultrasound transmitted from the ultrasound transducer 48 is generally set to a low output that does not destroy the bubbles contained in the contrast agent. Therefore, the S / N ratio of the image decreases, and the adverse effect of reduced sensitivity due to depolarization is likely to occur. Generally, the output is set low enough not to destroy the bubbles contained in the contrast agent, which reduces the signal-to-noise ratio of the image and makes it more susceptible to the adverse effects of reduced sensitivity due to depolarization.

[0098] In addition, when the depolarization of the ultrasonic transducer 48 progresses and the reception sensitivity thereof decreases, an ultrasonic image acquired at a position with a relatively deep display depth has a worse S / N ratio and is more likely to deteriorate in image quality than an ultrasonic image acquired at a position with a relatively shallow display depth. In response to this, the trigger generating circuit 156 can generate a trigger when the display depth of an ultrasonic image for performing ultrasonic diagnosis is set to a certain depth or more. According to a user's instruction, the display depth of an ultrasound image for performing ultrasound diagnosis can be set, for example, to a depth of 4 cm or a depth of 10 cm. For example, if the above-mentioned fixed depth is set to 5 cm, the trigger generating circuit 156 does not generate a trigger when the display depth of an ultrasound image is set to a depth of 4 cm, but generates a trigger when the display depth is set to a depth of 10 cm. The fixed depth may be a default value set in the trigger generating circuit 156, or may be set to an arbitrary depth by a user instruction.

[0099] Similarly, when the depolarization of the ultrasonic transducer 48 progresses and the reception sensitivity thereof decreases, the brightness of a B-mode ultrasonic image acquired at a position with a relatively deep display depth is more likely to decrease than that of a B-mode ultrasonic image acquired at a position with a relatively shallow display depth. In response to this, the trigger generating circuit 156 can generate a trigger when the brightness of a B-mode ultrasonic image acquired at a display depth set to a certain depth or more is equal to or lower than a certain brightness. The constant brightness may be a default brightness value set in the trigger generating circuit 156, or may be an arbitrary brightness that can be set according to a user instruction.

[0100] In addition, by analyzing the ultrasound images during the implementation of the ultrasound diagnosis, it is possible to recognize that the user is performing some kind of treatment while viewing the ultrasound images, such as during puncture, during release of a stent, or 30 minutes have passed since the start of acquisition of the ultrasound images. In this case, during treatment, the ultrasound images are often used in combination with endoscopic images and X-ray fluoroscopic images, and the details of the ultrasound images are not focused on as compared to when the ultrasound images are used as the main images to be watched, so that polarization processing can be performed suitably regardless of the image quality. In response to this, the trigger generating circuit 156 can generate a trigger when it is recognized based on the ultrasound images that the user is performing a treatment while viewing the ultrasound images.

[0101] Furthermore, the ultrasound diagnostic device 10 can obtain ultrasound images and endoscopic images, and can display these ultrasound images and endoscopic images on the monitor 20 in various display modes. As shown in Fig. 20, the display modes include a first display mode that displays only an ultrasound image, a second display mode that displays an ultrasound image larger than an endoscopic image by using picture-in-picture (PinP), a third display mode that displays an ultrasound image smaller than an endoscopic image by using PinP, and a fourth display mode that displays only an endoscopic image. The first to fourth display modes can be arbitrarily switched and displayed according to a user's instruction. In the third display mode, the ultrasound image is displayed smaller than the endoscopic image, so that polarization processing can be performed suitably regardless of the image quality. In response to this, the trigger generating circuit 156 is set to the third display mode and can generate a trigger when the ultrasound image is displayed smaller than the endoscopic image by picture-in-picture.

[0102] Although the above description has been given with reference to examples of factors that cause the trigger to occur, the trigger may be generated based on any factor other than the factors described above. In addition, possible conditions for terminating the polarization process include, for example, when the cumulative processing time of the polarization process reaches a certain time, when the user instructs to terminate the polarization process, when the contrast mode is changed to another ultrasound image generation mode, when the ultrasound display depth for performing ultrasound diagnosis is set to less than a certain depth, when it is no longer recognized based on the endoscopic image that the user is undergoing treatment, when the brightness of a B-mode ultrasound image acquired at a relatively deep ultrasound display depth becomes greater than a certain brightness, when the display mode is changed from the third display mode to another display mode, and the like, but the polarization process may be terminated based on other termination conditions.

[0103] <<Effectiveness of the Ultrasound Diagnostic Apparatus 10 of the Present Invention>> During the implementation of an ultrasonic diagnosis, the ultrasonic diagnostic device 10 performs polarization processing during a non-diagnostic period during which ultrasonic waves for performing an ultrasonic diagnosis and reflected waves are not transmitted, which is a period other than the period during which an image of each frame is acquired, during each frame time. Therefore, even during the implementation of an ultrasonic diagnosis, the frame rate does not decrease, so that the reception sensitivity of the multiple ultrasonic transducers 48 can be always maintained at a good level without degrading the image quality of the ultrasonic image, and therefore ultrasonic images of high image quality can always be acquired. Furthermore, since the ultrasonic diagnostic device 10 performs the polarization process using the existing transmission circuit 144, more specifically the pulse generating circuit 158, the polarization process can be performed during the period when the ultrasonic diagnosis is being performed without making significant changes to the existing circuitry.

[0104] The total number of ultrasonic transducers 48 and the number of aperture channels may be changed to any number. For example, when the number of aperture channels is the same as the total number of ultrasonic transducers 48, instead of the above-mentioned transmission signals for the two polarization processes, polarization processes 1 and 2, a transmission signal for one polarization process for driving 128 ultrasonic transducers 48 can be supplied. Alternatively, when the number of aperture channels is a quarter of the total number of ultrasonic transducers 48, four transmission signals for polarization processes, polarization processes 1 to 4, each of which drives 32 ultrasonic transducers 48, can be supplied.

[0105] In addition, the polarization process may be performed by combining the case of reducing the line density of the scanning lines, the case of reducing the number of scanning lines, and the case of reducing the line interval of the scanning lines. In addition, the polarization process may be performed by combining the case of reducing at least one of the line density, the number of lines, and the line interval of the scanning lines, and the case of making the time for performing the polarization process for the ultrasonic transducers 48 arranged in the center longer than that at both ends. In addition, the features of each of the above embodiments may be combined. Furthermore, the transmission circuit 144 may generate the first transmission signal using the first pulse generation circuit 158, and generate the second transmission signal using the second pulse generation circuit. In other words, the first transmission signal and the second transmission signal may be generated using pulse generation circuits in different transmission circuits 144.

[0106] In the above example, the non-diagnostic period during which ultrasound waves for performing ultrasound diagnosis are not transmitted and reflected waves are not received is a period other than the period during which each frame image is acquired during each frame time during which an image of each frame of an ultrasound image is acquired during the period during which ultrasound diagnosis is performed, but the present invention is not limited to this. In the present invention, the non-diagnostic period for performing the polarization process on the multiple ultrasonic transducers 48 may be any time or period as long as the transmission of ultrasonic waves for acquiring ultrasonic images and the reception of reflected waves are not performed, and may be a time or period other than the period during which ultrasonic diagnosis is performed. The polarization process may be performed on the multiple ultrasonic transducers 48 during any non-diagnostic time or period during which ultrasonic images are not acquired and ultrasonic diagnosis is not performed.

[0107] In the above example, after a trigger for starting polarization processing is given from the trigger generating circuit 156, polarization processing is performed during a non-diagnostic period during which ultrasound diagnosis is being performed. However, the present invention is not limited to this, and during the non-diagnostic time or period, polarization processing may be performed automatically or forcibly by hand upon entering the non-diagnostic time or period.

[0108] Furthermore, the present invention may further have an object to provide an ultrasonic diagnostic apparatus and an operating method of an ultrasonic diagnostic apparatus that can perform polarization processing during the implementation of ultrasonic diagnosis without affecting the image quality of an ultrasonic image. In addition to the above object, the present invention may further have an object to provide an ultrasonic diagnostic apparatus and an operating method of an ultrasonic diagnostic apparatus that can perform polarization processing without significantly modifying existing circuits.

[0109] Furthermore, the ultrasonic diagnostic device of the present invention may be an ultrasonic diagnostic device for acquiring ultrasonic images and endoscopic images, and may include an ultrasonic endoscope having an ultrasonic observation unit that transmits ultrasonic waves using an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, receives reflected ultrasonic waves, and outputs a received signal, and an ultrasonic processor device that visualizes the received signal to generate an ultrasonic image, and the ultrasonic processor device may include a trigger generating circuit that generates a trigger for starting polarization processing, and a control circuit that performs polarization processing on the plurality of ultrasonic transducers during a non-diagnostic period in which ultrasonic waves for performing ultrasonic diagnosis are not transmitted and reflected waves are not received, which is a period other than the period in which each frame image is acquired during each frame time in which each frame image of an ultrasonic image is acquired during an implementation period of ultrasonic diagnosis after the trigger is given, and during which ultrasonic waves for performing ultrasonic diagnosis are not transmitted and reflected waves are not received.

[0110] Here, the ultrasonic processor device further includes a transmission circuit that, under the control of the control circuit, uses a pulse generating circuit to generate transmission signals that drive multiple ultrasonic transducers to generate ultrasonic waves and supply the transmission signals to the multiple ultrasonic transducers, and it is preferable that, when performing ultrasonic diagnosis, the transmission circuit uses the pulse generating circuit to generate a first transmission signal for performing ultrasonic diagnosis, and, when performing polarization processing, the transmission circuit uses the same pulse generating circuit as that used for generating the first transmission signal to generate a second transmission signal for performing polarization processing. In addition, it is preferable that the control circuit generates a non-diagnostic period by reducing the line density, which represents the ratio of the number of scanning lines scanned within one frame time to the total number of multiple scanning lines scanned by electronic sector scanning to obtain one frame of an ultrasound image, and performs polarization processing within the generated non-diagnostic period.

[0111] In addition, it is preferable that the control circuit generates a non-diagnostic period by reducing the number of lines, which represents the number of scanning lines scanned within one frame time, among the multiple scanning lines scanned by electronic sector scanning to obtain one frame of an ultrasound image, and performs polarization processing within the generated non-diagnostic period. In addition, it is preferable that the control circuit generates a non-diagnostic period by reducing a line spacing that represents the time interval from when one of a plurality of scanning lines scanned by electronic sector scanning to obtain one frame of an ultrasound image is scanned to when the next scanning line is scanned, and performs polarization processing within the generated non-diagnostic period. In addition, when the number of ultrasonic transducers driven simultaneously during ultrasonic diagnosis is less than the total number of multiple ultrasonic transducers, it is preferable that the control circuit extends the time for performing polarization processing on the ultrasonic transducers located in the center rather than at both ends within each frame time.

[0112] Moreover, it is preferable that the trigger generating circuit generates a trigger when the cumulative driving time of a plurality of ultrasonic transducers for performing ultrasonic diagnosis reaches or exceeds a specified time. Moreover, it is preferable that the trigger generating circuit generates a trigger when a button for instructing the start of the polarization process is pressed. Moreover, it is preferable that the trigger generating circuit generates a trigger when the ultrasound image generating mode is set to a contrast mode in which a contrast image acquired using a contrast agent is highlighted. Moreover, it is preferable that the trigger generating circuit generates a trigger when the display depth of an ultrasonic image for performing ultrasonic diagnosis is set to a certain depth or more. Moreover, it is preferable that the trigger generating circuit generates a trigger when it is recognized based on the ultrasound image that the user is performing a treatment while viewing the ultrasound image. Moreover, it is preferable that the trigger generating circuit generates a trigger when the brightness of a B-mode ultrasonic image acquired with the display depth set to a certain depth or more is equal to or lower than a certain brightness. In addition, it is preferable that the trigger generating circuit generates a trigger when the ultrasound image is displayed smaller than the endoscopic image by picture-in-picture.

[0113] The present invention also provides an operating method of an ultrasonic diagnostic device that acquires ultrasonic images and endoscopic images, the operating method including the steps of: an ultrasonic observation unit provided in an ultrasonic endoscope of the ultrasonic diagnostic device transmits ultrasonic waves using an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, receives reflected waves of the ultrasonic waves, and outputs a received signal; and an ultrasonic processor device of the ultrasonic diagnostic device visualizes the received signal to generate an ultrasonic image, the step of generating an ultrasonic image including the steps of: a trigger generating circuit of the ultrasonic processor device generates a trigger for starting a polarization process; and a control circuit of the ultrasonic processor device performs polarization process on the plurality of ultrasonic transducers during a non-diagnostic period in which ultrasonic waves for performing ultrasonic diagnosis and reflected waves are not transmitted and reflected waves are not received, during each frame time in which an image of each frame of the ultrasonic image is acquired during a period in which ultrasonic diagnosis is performed, after the trigger is given.

[0114] Here, the step of generating an ultrasonic image further includes a step in which the transmission circuit of the ultrasonic processor device generates a transmission signal for driving the plurality of ultrasonic transducers to generate ultrasonic waves using a pulse generation circuit under the control of the control circuit, and supplies the transmission signal to the plurality of ultrasonic transducers; It is preferable that the step of generating a transmission signal includes the steps of: generating a first transmission signal for performing ultrasonic diagnosis using a pulse generating circuit when performing ultrasonic diagnosis; and generating a second transmission signal for performing polarization processing using the same pulse generating circuit as that used for generating the first transmission signal when performing polarization processing. In addition, it is preferable that the step of performing the polarization processing generates a non-diagnostic period by reducing the line density, which represents the ratio of the number of scanning lines scanned within one frame time to the total number of multiple scanning lines scanned by electronic sector scanning to obtain one frame of an ultrasound image, and performs the polarization processing within the generated non-diagnostic period.

[0115] In addition, it is preferable that the step of performing the polarization processing generates a non-diagnostic period by reducing the number of lines, which represents the number of scanning lines scanned within one frame time, among the multiple scanning lines scanned by electronic sector scanning to acquire one frame of an ultrasound image, and performs the polarization processing within the generated non-diagnostic period. In addition, it is preferable that the step of performing the polarization processing generates a non-diagnostic period by reducing a line spacing that represents the time interval from when one of a plurality of scanning lines scanned by electronic sector scanning to obtain one frame of an ultrasound image is scanned to when the next scanning line is scanned, and performs the polarization processing within the generated non-diagnostic period. In addition, when the number of ultrasonic transducers driven simultaneously during ultrasonic diagnosis is less than the total number of multiple ultrasonic transducers, it is preferable that the step of performing the polarization process is performed for a longer time for the ultrasonic transducers located in the center than for the transducers located at both ends within each frame time.

[0116] According to the present invention, furthermore, during the period of ultrasonic diagnosis, polarization processing is performed during a non-diagnostic period during which ultrasonic waves for performing ultrasonic diagnosis and reflected waves are not transmitted, which is a period other than the period during which an image of each frame is acquired, during each frame time. Therefore, even during the period of ultrasonic diagnosis, the frame rate does not decrease, so that the reception sensitivity of the multiple ultrasonic transducers can be always kept good without deteriorating the image quality of the ultrasonic image, and therefore ultrasonic images of high image quality can always be acquired. Furthermore, according to the present invention, since the polarization process is performed using an existing pulse generating circuit, the polarization process can be performed during the period in which ultrasonic diagnosis is being performed without making significant changes to the existing circuit.

[0117] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0118] 10. Ultrasound diagnostic equipment 12 Ultrasound Endoscope 14 Ultrasonic processor 16 Endoscope processor 18 Light source device 20 Monitor 21a Water tank 21b Suction pump 22 Insertion section 24 Control section 26 Universal Code 28a Water / air supply button 28b Suction button 29 Angle knob 30 Treatment tool insertion port 32a Ultrasonic Connector 32b Endoscope connector 32c Light Source Connector 34a Air and water supply tube 34b Suction tube 36 Ultrasound Observation Department 38 Endoscopic Observation Section 40 Tip 42 Curved section 43 Soft part 44 Treatment tool outlet 45 Instrument Channel 46 Ultrasonic transducer unit 48 Ultrasonic transducer 50 Ultrasound Transducer Array 54 Backing material layer 56 Coaxial Cable 58 Endoscope side memory 60 FPC 74 Acoustic matching layer 76 Acoustic Lens 82 Observation window 84 Objective Lens 86 Solid-state imaging element 88 Lighting window 90 Cleaning nozzle 92 Wiring cable 100 console 140 Multiplexer 142 Receiving circuit 144 Transmitting circuit 146 A / D Converter 148 ASIC 150 Cine Memory 151 Memory Controller 152 CPU 154 DSC 156 Trigger Generation Circuit 158 Pulse Generator Circuit 160 Phase matching box 162 B-mode image generation unit 164 PW mode image generator 166 CF mode image generator

Claims

1. An ultrasound diagnostic device for acquiring ultrasound images and endoscopic images, comprising: an ultrasonic endoscope including an ultrasonic observation unit that transmits ultrasonic waves using an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, and receives reflected waves of the ultrasonic waves; and an ultrasonic processor including a transmission circuit for transmitting a transmission signal to the plurality of ultrasonic transducers in order to generate the ultrasonic waves from the plurality of ultrasonic transducers, a reception circuit for outputting a reception signal based on the reflected waves received by the plurality of ultrasonic transducers, and an ultrasonic image generating unit for imaging the reception signal to generate the ultrasonic image in order to obtain the ultrasonic image, The ultrasonic transducers are all single crystal transducers, The thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, The ultrasonic processor further includes a control circuit that transmits the ultrasonic waves and receives the reflected waves, and causes the transmission circuit to perform polarization processing on the ultrasonic transducers. When acquiring the ultrasonic image, the control circuit controls the transmission circuit to generate the transmission signal consisting of a diagnostic drive pulse to be applied to each of the plurality of ultrasonic transducers that generate the ultrasonic waves to acquire the ultrasonic image, and when performing the polarization process, controls the transmission circuit to generate a polarization drive pulse having a different magnitude within the same settable voltage range as the diagnostic drive pulse and a different frequency from a probe frequency band for acquiring the ultrasonic image, in order to perform the polarization process of the plurality of ultrasonic transducers. Applying the polarization drive pulse to the plurality of ultrasonic transducers, and performing the polarization process of the plurality of ultrasonic transducers with the polarization drive pulse; The control circuit controls the transmission circuit so that the probe frequency band and the frequency band of the main lobe of the drive waveform of the polarization drive pulse that drives the multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more.

2. An ultrasound diagnostic device for acquiring ultrasound images and endoscopic images, comprising: an ultrasonic endoscope including an ultrasonic observation unit that transmits ultrasonic waves using an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, and receives reflected waves of the ultrasonic waves; and an ultrasonic processor including a transmission circuit for transmitting a transmission signal to the plurality of ultrasonic transducers in order to generate the ultrasonic waves from the plurality of ultrasonic transducers, a reception circuit for outputting a reception signal based on the reflected waves received by the plurality of ultrasonic transducers, and an ultrasonic image generating unit for imaging the reception signal to generate the ultrasonic image in order to obtain the ultrasonic image, The ultrasonic transducers are all single crystal transducers, The thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, The ultrasonic processor further includes a control circuit that transmits the ultrasonic waves and receives the reflected waves, and causes the transmission circuit to perform polarization processing on the ultrasonic transducers. When acquiring the ultrasonic image, the control circuit controls the transmission circuit to generate the transmission signal consisting of a diagnostic drive pulse to be applied to each of the plurality of ultrasonic transducers that generate the ultrasonic waves to acquire the ultrasonic image, and when performing the polarization process, controls the transmission circuit to generate a polarization drive pulse having a different magnitude within the same settable voltage range as the diagnostic drive pulse and a different frequency from a probe frequency band for acquiring the ultrasonic image, in order to perform the polarization process of the plurality of ultrasonic transducers. Applying the polarization drive pulse to the plurality of ultrasonic transducers, and performing the polarization process of the plurality of ultrasonic transducers with the polarization drive pulse; The plurality of ultrasonic transducers on the ultrasonic transducer array are grouped into a plurality of groups, and the ultrasonic transducers in each group are independently polarized using a transmission signal that performs a different polarization process for each group.

3. The ultrasonic diagnostic apparatus according to claim 2, wherein the control circuit controls the transmission circuit so that the probe frequency band and the frequency band of the main lobe of the drive waveform of the polarization drive pulse that drives the multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more.

4. 4. The ultrasonic diagnostic apparatus according to claim 1, wherein the frequency band of the main lobe of the drive waveform of the polarization drive pulse is lower than the probe frequency band.

5. 5. The ultrasonic diagnostic device according to claim 1, 3, or 4, wherein the sensitivities of one or more side lobes accompanying the main lobe in the drive waveform of the polarization drive pulse within the probe frequency band are all 10 dB or less, and the average sensitivity of the one or more side lobes is −20 dB or less.

6. 6. The ultrasonic diagnostic apparatus according to claim 1, wherein the frequency band of the main lobe of the drive waveform of the polarization drive pulse is 2.3 MHz or less.

7. 7. The ultrasonic diagnostic apparatus according to claim 1, wherein the probe frequency band is 2.7 MHz to 11.7 MHz.

8. 8. The ultrasonic diagnostic apparatus according to claim 1, wherein the drive waveform of the polarization drive pulse is a unipolar waveform.

9. 9. The ultrasonic diagnostic apparatus according to claim 8, wherein the transmission circuit outputs a plurality of unipolar waveforms as the polarization drive pulses, with an interval between the waveforms being a minimum number of clocks defined in the transmission circuit.

10. 10. The ultrasonic diagnostic apparatus according to claim 1, wherein the polarization drive voltage is higher than an imaging drive voltage of the diagnostic drive pulse.

11. the image driving voltage of the diagnostic driving pulse and the polarization driving voltage of the polarization driving pulse have the same settable voltage range, 11. The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission circuit switches between the image driving voltage and the polarization driving voltage.

12. A method for operating an ultrasound diagnostic device for acquiring ultrasound images and endoscopic images, comprising the steps of: The ultrasonic diagnostic device includes an ultrasonic endoscope having an ultrasonic observation unit having an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, a transmission circuit for transmitting a transmission signal to the plurality of ultrasonic transducers, a reception circuit for outputting a reception signal based on a reflected wave received by the plurality of ultrasonic transducers, and an ultrasonic processor device having an ultrasonic image generation unit that visualizes the reception signal and generates the ultrasonic image. The ultrasonic transducers are all single crystal transducers, The thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, controlling the transmission circuit to generate the transmission signal consisting of a diagnostic drive pulse to be applied to each of the plurality of ultrasonic transducers that generate ultrasonic waves to acquire the ultrasonic image; transmitting the transmission signal generated from the transmission circuit to the plurality of ultrasonic transducers and applying the diagnostic drive pulse to the plurality of ultrasonic transducers to generate the ultrasonic waves; receiving the reflected waves of the ultrasonic waves by the plurality of ultrasonic transducers; outputting a reception signal based on the reflected waves received by the plurality of ultrasonic transducers from the reception circuit; The ultrasonic image generating unit receives the reception signal and converts the reception signal into an image to generate the ultrasonic image. A step of controlling the transmission circuit to generate polarization drive pulses having different polarization drive voltages within the same settable voltage range as the diagnostic drive pulses and different frequencies from a probe frequency band for acquiring the ultrasound image, in order to perform polarization processing of the plurality of ultrasonic transducers; applying the polarization drive pulse to the plurality of ultrasonic transducers to perform the polarization process of the plurality of ultrasonic transducers with the polarization drive pulse; A method for operating an ultrasonic diagnostic device, comprising: a step of controlling the transmission circuit to generate the transmission signal consisting of the diagnostic drive pulse, the step of controlling the transmission circuit so that the probe frequency band and the frequency band of the main lobe of the drive waveform of the polarization drive pulse that drives the multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more.

13. A method for operating an ultrasound diagnostic device for acquiring ultrasound images and endoscopic images, comprising: The ultrasonic diagnostic device includes an ultrasonic endoscope having an ultrasonic observation unit having an ultrasonic transducer array in which a plurality of ultrasonic transducers are arranged, a transmission circuit for transmitting a transmission signal to the plurality of ultrasonic transducers, a reception circuit for outputting a reception signal based on a reflected wave received by the plurality of ultrasonic transducers, and an ultrasonic processor device having an ultrasonic image generation unit that visualizes the reception signal and generates the ultrasonic image. The ultrasonic transducers are all single crystal transducers, The thickness of the piezoelectric element constituting each of the plurality of ultrasonic transducers is 75 μm to 125 μm, controlling the transmission circuit to generate the transmission signal consisting of a diagnostic drive pulse to be applied to each of the plurality of ultrasonic transducers that generate ultrasonic waves to acquire the ultrasonic image; transmitting the transmission signal generated from the transmission circuit to the plurality of ultrasonic transducers and applying the diagnostic drive pulse to the plurality of ultrasonic transducers to generate the ultrasonic waves; receiving the reflected waves of the ultrasonic waves by the plurality of ultrasonic transducers; outputting a reception signal based on the reflected waves received by the plurality of ultrasonic transducers from the reception circuit; The ultrasonic image generating unit receives the reception signal and converts the reception signal into an image to generate the ultrasonic image. A step of controlling the transmission circuit to generate polarization drive pulses having different polarization drive voltages within the same settable voltage range as the diagnostic drive pulses and different frequencies from a probe frequency band for acquiring the ultrasound image, in order to perform polarization processing of the plurality of ultrasonic transducers; applying the polarization drive pulse to the plurality of ultrasonic transducers to perform the polarization process of the plurality of ultrasonic transducers with the polarization drive pulse; A method for operating an ultrasonic diagnostic device, in which the plurality of ultrasonic transducers on the ultrasonic transducer array are grouped into a plurality of groups, and the ultrasonic transducers in each group are independently polarized by a different transmission signal that performs polarization processing for each group.

14. The method for operating an ultrasonic diagnostic apparatus according to claim 13, wherein the step of controlling the transmission circuit to generate the transmission signal consisting of the diagnostic drive pulse controls the transmission circuit so that the probe frequency band and the frequency band of a main lobe of the drive waveform of the polarization drive pulse that drives the multiple ultrasonic transducers when performing the polarization process do not overlap at a sensitivity level of -20 dB or more.

15. 15. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein a frequency band of the main lobe of the drive waveform of the polarization drive pulse is lower than a frequency band of the probe.

16. The method for operating an ultrasonic diagnostic apparatus according to claim 12, 14 or 15, wherein the sensitivities of one or more side lobes accompanying the main lobe in the drive waveform of the polarization drive pulse within the probe frequency band are all 10 dB or less, and the average sensitivity of the one or more side lobes is -20 dB or less.

17. 17. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein the frequency band of the main lobe of the drive waveform of the polarization drive pulse is 2.3 MHz or less.

18. 18. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein the probe frequency band is from 2.7 MHz to 11.7 MHz.

19. 19. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein the drive waveform of the polarization drive pulse is a unipolar waveform.

20. 20. The method of claim 19, wherein the step of controlling the transmission circuit to generate the polarization drive pulse includes controlling the transmission circuit to output, as the polarization drive pulse, a plurality of unipolar waveforms, the waveforms spaced apart by a time interval equal to a minimum number of clocks defined in the transmission circuit.

21. 21. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein the polarization drive voltage is a voltage higher than an imaging drive voltage of the diagnostic drive pulse.

22. the image driving voltage of the diagnostic driving pulse and the polarization driving voltage of the polarization driving pulse have the same settable voltage range, 22. The method for operating an ultrasonic diagnostic apparatus according to claim 12, wherein the transmission circuit switches between the image driving voltage and the polarization driving voltage.

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