Patent Description:
An ultrasound diagnostic apparatus that acquires an ultrasound image of the inside of a subject by transmitting and receiving ultrasound waves by driving a plurality of ultrasound transducers inside the subject is already known. In the ultrasound diagnostic apparatus, the plurality of ultrasound transducers are, for example, single crystal transducers that are piezoelectric elements, and are usually used in a polarized state. The ultrasound transducer that is a single crystal transducer can receive ultrasound waves with high sensitivity, but a depolarization phenomenon in which the degree of polarization decreases as the driving time increases may occur. In a case where a depolarization phenomenon occurs, the reception sensitivity of the ultrasound transducer decreases, which may affect the image quality of the ultrasound image.

In particular, in the case of transmitting and receiving ultrasound waves by driving each ultrasound transducer inside the subject, since it is necessary to set the frequency of the ultrasound wave to a high frequency band of <NUM> to <NUM> level, a transducer having a relatively small thickness is used. However, as the thickness of the transducer decreases, the risk of occurrence of a depolarization phenomenon increases.

For this reason, techniques for countermeasures against depolarization in the ultrasound diagnostic apparatus have been developed so far. For example, an ultrasound diagnostic apparatus (referred to as a "piezoelectric sensor apparatus" in <CIT>) described in <CIT> has a piezoelectric element having a piezoelectric body and a pair of electrodes interposing the piezoelectric body therebetween, a detection circuit for performing detection processing for detecting a detection signal output from the piezoelectric element, and a polarization processing circuit for performing polarization processing by applying a polarization voltage to the piezoelectric element. In the ultrasound diagnostic apparatus described in <CIT> having such a configuration, polarization processing is performed at a timing at which the electric power is supplied, a timing at which a request signal for executing detection processing is input (each reception timing), or a timing at which a predetermined standby transition time has passed after the end of detection processing, for example. Therefore, even in a case where a depolarization phenomenon occurs in the piezoelectric element, the piezoelectric element can be polarized again. As a result, it is possible to maintain the reception sensitivity of the piezoelectric element.

As another example, an ultrasound diagnostic apparatus (referred to as an "ultrasound sensor" in <CIT>) described in <CIT> has a piezoelectric element and a driving circuit for driving the piezoelectric element. The driving circuit drives the piezoelectric element with a driving waveform having first to sixth steps. The first step is a step of maintaining the polarization of the piezoelectric element with a first potential V1. The second step is a step of transmitting an ultrasound wave to the piezoelectric element after the first step. The third step is a step of causing the piezoelectric element to stand by at a second potential V2 after the second step. The fourth step is a step of increasing the second potential V2 to a third potential V3 after the third step. The fifth step is a step of maintaining the third potential V3 while the piezoelectric element receives an ultrasound wave after the fourth step. The sixth step is a step of returning the third potential V3 to the first potential V1 after the fifth step. In the ultrasound diagnostic apparatus described in <CIT> having such a configuration, it is possible to drive the piezoelectric element while maintaining the polarization of the piezoelectric element by driving the piezoelectric element with the driving waveform having the first to sixth steps described above.

<CIT> discloses an ultrasonic transducer device, probe, electronic instrument, and ultrasonic diagnostic device. The transducer device includes a substrate, a vibrating film, a piezoelectric element, an input section and a detection section. The input section is configured and arranged to input a drive signal to a part of piezoelectric elements among the piezoelectric elements. The detection section is configured and arranged to detect vibration of the piezoelectric elements, in which the drive signal is not inputted, among the piezoelectric elements while the drive signal is inputted to the part of the piezoelectric elements among the piezoelectric elements. <CIT> discloses a piezoelectric sensor device and piezoelectric sensor device drive method. <CIT> discloses a repolarization system which repolarizes transducer used in ultrasonic probe.

As described above, in the ultrasound diagnostic apparatus described in each of <CIT> and <CIT>, it is possible to restore or maintain the polarization of the piezoelectric element.

However, as in the ultrasound diagnostic apparatus described in <CIT>, providing a dedicated circuit for performing repolarization, a depolarization detection mechanism, and the like is a large hardware change factor. Accordingly, it is very difficult to mount those described above in the existing system.

In the ultrasound diagnostic apparatus described in <CIT>, in order to maintain polarization, the pulse length of the driving waveform is increased by inserting a DC component into each driving waveform. Accordingly, the frame rate may be reduced to affect the image quality of the ultrasound image.

Therefore, it is a first object of the invention to provide an ultrasound diagnostic apparatus and an operation method of an ultrasound diagnostic apparatus capable of performing polarization processing during the execution period of ultrasound diagnosis without affecting the image quality of an ultrasound image.

In addition to the first object described above, it is a second object of the invention to provide an ultrasound diagnostic apparatus and an operation method of an ultrasound diagnostic apparatus capable of performing polarization processing without significantly changing the existing circuit.

In order to achieve the aforementioned object, the invention provides an ultrasound diagnostic apparatus according to claim <NUM> of the appended claims.

Here, it is preferable that the ultrasound processor apparatus further comprises a transmission circuit that generates a transmission signal for driving the plurality of ultrasound transducers to generate the ultrasound waves using a pulse generation circuit and supplies the transmission signal to the plurality of ultrasound transducers under control of the control circuit and that the transmission circuit generates a first transmission signal for performing the ultrasound diagnosis using the pulse generation circuit in a case of performing the ultrasound diagnosis and generates a second transmission signal for performing the polarization processing using the same pulse generation circuit as in the case of generating the first transmission signal in a case of performing the polarization processing.

It is preferable that the control circuit generates the non-diagnosis period by reducing a line density, which indicates a ratio of the number of scanning lines scanned within one frame time to the total number of a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image, and performs the polarization processing within the generated non-diagnosis period.

It is preferable that the control circuit generates the non-diagnosis period by reducing the number of lines, which indicates the number of scanning lines scanned within one frame time among a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image, and performs the polarization processing within the generated non-diagnosis period.

It is preferable that the control circuit generates the non-diagnosis period by reducing a line interval, which indicates an interval of time from scanning of one scanning line among a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image to scanning of the next scanning line, and performs the polarization processing within the generated non-diagnosis period.

It is preferable that, in a case where the number of ultrasound transducers driven simultaneously is less than the total number of the plurality of ultrasound transducers during the ultrasound diagnosis, the control circuit sets a time for performing the polarization processing on ultrasound transducers disposed at a central portion to be longer than a time for performing the polarization processing on ultrasound transducers disposed at both end portions within each frame time.

It is preferable that the trigger generation circuit generates the trigger in a case where a cumulative driving time of the plurality of ultrasound transducers for performing the ultrasound diagnosis becomes equal to or greater than a specified time.

It is preferable that the trigger generation circuit generates the trigger in a case where a button for giving an instruction to start the polarization processing is pressed.

It is preferable that the trigger generation circuit generates the trigger in a case where an ultrasound image generation mode is set to a contrast mode in which a contrast image acquired using a contrast medium is highlighted.

It is preferable that the trigger generation circuit generates the trigger in a case where a display depth of the ultrasound image for performing the ultrasound diagnosis is set to a predetermined depth or more.

It is preferable that the trigger generation circuit generates the trigger in a case where it is recognized based on the ultrasound image that a user is performing treatment while viewing the ultrasound image.

It is preferable that the trigger generation circuit generates the trigger in a case where a brightness of a B mode ultrasound image, which is acquired in a state in which a display depth is set to a predetermined depth or more, is equal to or less than a predetermined brightness.

It is preferable that the trigger generation circuit generates the trigger in a case where the ultrasound image is displayed so as to be smaller than the endoscope image by picture in picture.

In addition, the invention provides an operation method of an ultrasound diagnostic apparatus for acquiring an ultrasound image and an endoscope image. The operation method of an ultrasound diagnostic apparatus comprises: a step in which an ultrasound observation portion that an ultrasound endoscope of the ultrasound diagnostic apparatus comprises transmits ultrasound waves using an ultrasound transducer array in which a plurality of ultrasound transducers are arranged, receives reflected waves of the ultrasound waves, and outputs a reception signal; and a step in which an ultrasound processor apparatus of the ultrasound diagnostic apparatus generates the ultrasound image by converting the reception signal into an image. The step of generating the ultrasound image includes: a step in which a trigger generation circuit of the ultrasound processor apparatus generates a trigger for starting polarization processing; and a step in which a control circuit of the ultrasound processor apparatus performs the polarization processing on the plurality of ultrasound transducers in a non-diagnosis period, which is a period other than a period for acquiring an image of each frame and during which transmission of the ultrasound waves and reception of the reflected waves for performing ultrasound diagnosis are not performed, within each frame time in which an image of each frame of the ultrasound image is acquired during an execution period of the ultrasound diagnosis after the trigger is given.

Here, it is preferable that the step of generating the ultrasound image further includes a step in which a transmission circuit of the ultrasound processor apparatus generates a transmission signal for driving the plurality of ultrasound transducers to generate the ultrasound waves using a pulse generation circuit and supplies the transmission signal to the plurality of ultrasound transducers under control of the control circuit and that the step of generating the transmission signal includes a step of generating a first transmission signal for performing the ultrasound diagnosis using the pulse generation circuit in a case of performing the ultrasound diagnosis and a step of generating a second transmission signal for performing the polarization processing using the same pulse generation circuit as in the case of generating the first transmission signal in a case of performing the polarization processing.

It is preferable that, in the step of performing the polarization processing, the non-diagnosis period is generated by reducing a line density, which indicates a ratio of the number of scanning lines scanned within one frame time to the total number of a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image, and the polarization processing is performed within the generated non-diagnosis period.

It is preferable that, in the step of performing the polarization processing, the non-diagnosis period is generated by reducing the number of lines, which indicates the number of scanning lines scanned within one frame time among a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image, and the polarization processing is performed within the generated non-diagnosis period.

It is preferable that, in the step of performing the polarization processing, the non-diagnosis period is generated by reducing a line interval, which indicates an interval of time from scanning of one scanning line among a plurality of scanning lines scanned by electronic sector scanning for acquiring an image of one frame of the ultrasound image to scanning of the next scanning line, and the polarization processing is performed within the generated non-diagnosis period.

It is preferable that, in the step of performing the polarization processing, in a case where the number of ultrasound transducers driven simultaneously is less than the total number of the plurality of ultrasound transducers during the ultrasound diagnosis, a time for performing the polarization processing on ultrasound transducers disposed at a central portion is set to be longer than a time for performing the polarization processing on ultrasound transducers disposed at both end portions within each frame time.

According to the invention, in a non-diagnosis period, which is a period other than the acquisition period of an image of each frame and during which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are not performed, within each frame time during the execution period of ultrasound diagnosis, the polarization processing is performed. Therefore, even during the execution period of the ultrasound diagnosis, the frame rate is not reduced. As a result, since the reception sensitivities of the plurality of ultrasound transducers can always be kept satisfactory without reducing the image quality of the ultrasound image, a high-quality ultrasound image can always be acquired.

In addition, according to the invention, since the polarization processing is performed using the existing pulse generation circuit, it is possible to perform the polarization processing during the execution period of the ultrasound diagnosis without significantly changing the existing circuit.

An ultrasound diagnostic apparatus according to an embodiment (the present embodiment) of the invention will be described in detail below with reference to preferred embodiments shown in the accompanying diagrams.

The present embodiment is a representative embodiment of the invention, but is merely an example and does not limit the invention.

In addition, in this specification, the numerical range expressed by using "~" means a range including numerical values described before and after "~" as a lower limit and an upper limit.

The outline of an ultrasound diagnostic apparatus <NUM> according to the present embodiment will be described with reference to <FIG> is a diagram showing the schematic configuration of ultrasound diagnostic apparatus <NUM>.

The ultrasound diagnostic apparatus <NUM> is used to observe (hereinafter, also referred to as ultrasound diagnosis) the state of an observation target part in a body of a patient, who is a subject, using ultrasound waves. Here, the observation target part is a part that is difficult to examine from the body surface side of the patient, for example, a gallbladder or a pancreas. By using the ultrasound diagnostic apparatus <NUM>, it is possible to perform ultrasound diagnosis of the state of the observation target part and the presence or absence of an abnormality through gastrointestinal tracts such as esophagus, stomach, duodenum, small intestine, and large intestine which are body cavities of the patient.

The ultrasound diagnostic apparatus <NUM> acquires an ultrasound image and an endoscope image, and as shown in <FIG>, has an ultrasound endoscope <NUM>, an ultrasound processor apparatus <NUM>, an endoscope processor apparatus <NUM>, a light source device <NUM>, a monitor <NUM>, a water supply tank 21a, a suction pump 21b, and a console <NUM>.

The ultrasound endoscope <NUM> is an endoscope, and comprises an insertion part <NUM> to be inserted into the body cavity of a patient, an operation unit <NUM> operated by an operator (user), such as a doctor or a technician, and an ultrasound transducer unit <NUM> attached to a distal end portion <NUM> of the insertion part <NUM> (refer to <FIG> and <FIG>). By the function of the ultrasound endoscope <NUM>, the operator can acquire an endoscope image of the inner wall of the body cavity of the patient and an ultrasound image of the observation target part.

Here, the "endoscope image" is an image obtained by imaging the inner wall of the body cavity of the patient using an optical method. The "ultrasound image" is an image obtained by receiving a reflected wave (echo) of an ultrasound wave transmitted from the inside of the body cavity of the patient to the observation target part and converting the reception signal into an image.

The ultrasound endoscope <NUM> will be described in detail later.

The ultrasound processor apparatus <NUM> is connected to the ultrasound endoscope <NUM> through a universal cord <NUM> and an ultrasound connector 32a provided at an end portion of the universal cord <NUM>. The ultrasound processor apparatus <NUM> controls the ultrasound transducer unit <NUM> of the ultrasound endoscope <NUM> to transmit the ultrasound wave. In addition, the ultrasound processor apparatus <NUM> generates an ultrasound image by converting the reception signal in a case where the reflected wave (echo) of the transmitted ultrasound wave is received by the ultrasound transducer unit <NUM> into an image.

The ultrasound processor apparatus <NUM> will be described in detail later.

The endoscope processor apparatus <NUM> is connected to the ultrasound endoscope <NUM> through the universal cord <NUM> and an endoscope connector 32b provided at an end portion of the universal cord <NUM>. The endoscope processor apparatus <NUM> generates an endoscope image by acquiring image data of an observation target adjacent part imaged by the ultrasound endoscope <NUM> (more specifically, a solid-state imaging element <NUM> to be described later) and performing predetermined image processing on the acquired image data.

Here, the "observation target adjacent part" is a portion of the inner wall of the body cavity of the patient that is adjacent to the observation target part.

In the present embodiment, the ultrasound processor apparatus <NUM> and the endoscope processor apparatus <NUM> are formed by two apparatuses (computers) provided separately. However, the invention is not limited thereto, and both the ultrasound processor apparatus <NUM> and the endoscope processor apparatus <NUM> may be formed by one apparatus.

The light source device <NUM> is connected to the ultrasound endoscope <NUM> through the universal cord <NUM> and a light source connector 32c provided at an end portion of the universal cord <NUM>. The light source device <NUM> emits white light or specific wavelength light formed of three primary color light components of red light, green light, and blue light at the time of imaging the observation target adjacent part using the ultrasound endoscope <NUM>. The light emitted from the light source device <NUM> propagates through the ultrasound endoscope <NUM> through a light guide (not shown) included in the universal cord <NUM>, and is emitted from the ultrasound endoscope <NUM> (more specifically, an illumination window <NUM> to be described later). As a result, the observation target adjacent part is illuminated with the light from the light source device <NUM>.

The monitor <NUM> is connected to the ultrasound processor apparatus <NUM>, and the endoscope processor apparatus <NUM>, and displays an ultrasound image generated by the ultrasound processor apparatus <NUM> and an endoscope image generated by the endoscope processor apparatus <NUM>. As a display method of the ultrasound image and the endoscope image, either one of the images may be switched and displayed on the monitor <NUM>, or both the images may be displayed at the same time. Display modes of the ultrasound image and the endoscope image will be described later.

In the present embodiment, the ultrasound image and the endoscope image are displayed on one monitor <NUM>. However, a monitor for displaying the ultrasound image and a monitor for displaying the endoscope image may be separately provided. In addition, the ultrasound image and the endoscope image may be displayed in a display form other than the monitor <NUM>. For example, the ultrasound image and the endoscope image may be displayed on a display of a terminal carried by the operator.

The console <NUM> is an apparatus provided for the operator to input information necessary for ultrasound diagnosis or for the operator to instruct the ultrasound processor apparatus <NUM> to start ultrasound diagnosis. The console <NUM> is configured to include, for example, a keyboard, a mouse, a trackball, a touch pad, and a touch panel. In a case where the console <NUM> is operated, a CPU (control circuit) <NUM> (refer to <FIG>) of the ultrasound processor apparatus <NUM> controls each unit of the apparatus (for example, a reception circuit <NUM> and a transmission circuit <NUM> to be described later) according to the operation content.

Specifically, the operator inputs examination information (for example, examination order information including a date, an order number, and the like and patient information including a patient ID, a patient name, and the like) through the console <NUM> before starting the ultrasound diagnosis. In a case where the operator gives an instruction to start the ultrasound diagnosis through the console <NUM> after the input of the examination information is completed, the CPU <NUM> of the ultrasound processor apparatus <NUM> controls each unit of the ultrasound processor apparatus <NUM> so that the ultrasound diagnosis is performed based on the input examination information.

The operator can set various control parameters with the console <NUM> at the time of performing the ultrasound diagnosis. As the control parameters, for example, selection results of a live mode and a freeze mode, set values of the display depth (depth), selection results of an ultrasound image generation mode, and the like can be mentioned.

Here, the "live mode" is a mode in which ultrasound images (moving images) obtained at a predetermined frame rate are sequentially displayed (displayed in real time). The "freeze mode" is a mode in which an image (still image) of one frame of an ultrasound image (moving image) generated in the past is read out from a cine memory <NUM> to be described later and displayed.

There are a plurality of ultrasound image generation modes that can be selected in the present embodiment. Specifically, there are a brightness (B) mode, a color flow (CF) mode, and a pulse wave (PW) mode. The B mode is a mode in which a tomographic image is displayed by converting the amplitude of the ultrasound echo into a brightness. The CF mode is a mode in which average blood flow speed, flow fluctuation, strength of flow signal, flow power, and the like are mapped to various colors and displayed so as to be superimposed on a B mode image. The PW mode is a mode in which the speed (for example, blood flow speed) of the ultrasound echo source detected based on the transmission and reception of the pulse wave is displayed.

The ultrasound image generation modes described above are merely examples, and modes other than the above-described three kinds of modes, for example, an amplitude (A) mode, a motion (M) mode, and a contrast mode may be further included.

Next, the configuration of the ultrasound endoscope <NUM> will be described with reference to <FIG>. <FIG> is an enlarged plan view showing a distal end portion of an insertion part <NUM> of an ultrasound endoscope <NUM> and the periphery thereof. <FIG> is a cross-sectional view showing a cross section of the distal end portion <NUM> of the insertion part <NUM> of the ultrasound endoscope <NUM> taken along the line I-I in <FIG>. <FIG> is a block diagram showing the configuration of the ultrasound processor apparatus <NUM>.

As described above the ultrasound endoscope <NUM> has the insertion part <NUM> and the operation unit <NUM>. As shown in <FIG>, the insertion part <NUM> comprises the distal end portion <NUM>, a bending portion <NUM>, and a flexible portion <NUM> in order from the distal end side (free end side). As shown in <FIG>, an ultrasound observation portion <NUM> and an endoscope observation portion <NUM> are provided in the distal end portion <NUM>. As shown in <FIG>, the ultrasound transducer unit <NUM> comprising a plurality of ultrasound transducers <NUM> is disposed in the ultrasound observation portion <NUM>.

As shown in <FIG>, a treatment tool lead-out port <NUM> is provided in the distal end portion <NUM>. The treatment tool lead-out port <NUM> serves as an outlet of a treatment tool (not shown), such as forceps, an insertion needle, or a high frequency scalpel. In addition, the treatment tool lead-out port <NUM> serves as a suction port in the case of sucking aspirates, such as blood and body waste.

The bending portion <NUM> is a portion continuously provided on the more proximal side (side opposite to the side where the ultrasound transducer unit <NUM> is provided) than the distal end portion <NUM>, and can bend freely. The flexible portion <NUM> is a portion connecting the bending portion <NUM> and the operation unit <NUM> to each other, has flexibility, and is provided so as to extend in an elongated state.

A plurality of pipe lines for air and water supply and a plurality of pipe lines for suction are formed in the insertion part <NUM> and the operation unit <NUM>, respectively. In addition, a treatment tool channel <NUM> whose one end communicates with the treatment tool lead-out port <NUM> is formed in each of the insertion part <NUM> and the operation unit <NUM>.

Next, the ultrasound observation portion <NUM>, the endoscope observation portion <NUM>, the water supply tank 21a, the suction pump 21b, and the operation unit <NUM> among the components of the ultrasound endoscope <NUM> will be described in detail.

The ultrasound observation portion <NUM> is a portion provided to acquire an ultrasound image, and is disposed on the distal end side in the distal end portion <NUM> of the insertion part <NUM>. As shown in <FIG>, the ultrasound observation portion <NUM> comprises the ultrasound transducer unit <NUM>, a plurality of coaxial cables <NUM>, and a flexible printed circuit (FPC) <NUM>.

The ultrasound transducer unit <NUM> corresponds to an ultrasound probe (probe), and transmits an ultrasound wave using an ultrasound transducer array <NUM>, in which a plurality of ultrasound transducers <NUM> to be described later are arranged, in the body cavity of the patient, receives a reflected wave (echo) of the ultrasound wave reflected by the observation target part, and outputs a reception signal. The ultrasound transducer unit <NUM> according to the present embodiment is a convex type, and transmits an ultrasound wave radially (in an arc shape). However, the type (model) of the ultrasound transducer unit <NUM> is not particularly limited, and other types may be used as long as it is possible to transmit and receive ultrasound waves. For example, a sector type, a linear type, and a radial type may be used.

As shown in <FIG>, the ultrasound transducer unit <NUM> is formed by laminating a backing material layer <NUM>, an ultrasound transducer array <NUM>, an acoustic matching layer <NUM>, and an acoustic lens <NUM>.

The ultrasound transducer array <NUM> includes a plurality of ultrasound transducers <NUM> (ultrasound transducers) arranged in a one-dimensional array. More specifically, the ultrasound transducer array <NUM> is formed by arranging N (for example, N = <NUM>) ultrasound transducers <NUM> at equal intervals in a convex bending shape along the axial direction of the distal end portion <NUM> (longitudinal axis direction of the insertion part <NUM>). The ultrasound transducer array <NUM> may be one in which a plurality of ultrasound transducers <NUM> are disposed in a two-dimensional array.

Each of the N ultrasound transducers <NUM> is formed by disposing electrodes on both surfaces of a single crystal transducer that is a piezoelectric element. As the single crystal transducer, any of quartz, lithium niobate, lead magnesium niobate (PMN), lead zinc niobate (PZN), lead indium niobate (PIN), lead titanate (PT), lead magnesium niobate-lead titanate (PMN-PT), zinc niobate-lead titanate (PZN-PT), lithium tantalate, langasite, and zinc oxide can be used.

The electrodes is an individual electrode (not shown) individually provided for each of the plurality of ultrasound transducers <NUM> and a transducer ground (not shown) common to the plurality of ultrasound transducers <NUM>. In addition, the electrodes are electrically connected to the ultrasound processor apparatus <NUM> through the coaxial cable <NUM> and the FPC <NUM>.

The ultrasound transducer <NUM> according to the present embodiment needs to be driven (vibrated) at a relatively high frequency of <NUM> to <NUM> level in order to acquire an ultrasound image in the body cavity of the patient. For this reason, the thickness of the piezoelectric element forming the ultrasound transducer <NUM> is designed to be relatively small. For example, the thickness of the piezoelectric element forming the ultrasound transducer <NUM> is <NUM> to <NUM>, preferably <NUM> to <NUM>.

A pulsed driving voltage is supplied from the ultrasound processor apparatus <NUM> to each ultrasound transducer <NUM>, as an input signal (transmission signal), through the coaxial cable <NUM>. In a case where the driving voltage is applied to the electrodes of the ultrasound transducer <NUM>, the piezoelectric element expands and contracts to drive (vibrate) the ultrasound transducer <NUM>. As a result, a pulsed ultrasound wave is output from the ultrasound transducer <NUM>. In this case, the amplitude of the ultrasound wave output from the ultrasound transducer <NUM> has a magnitude corresponding to the intensity (output intensity) in a case where the ultrasound transducer <NUM> outputs the ultrasound wave. Here, the output intensity is defined as the magnitude of the sound pressure of the ultrasound wave output from the ultrasound transducer <NUM>.

Each ultrasound transducer <NUM> vibrates (is driven) upon receiving the reflected wave (echo) of the ultrasound wave, and the piezoelectric element of each ultrasound transducer <NUM> generates an electric signal. The electric signal is output from each ultrasound transducer <NUM> to the ultrasound processor apparatus <NUM> as a reception signal of the ultrasound wave. In this case, the magnitude (voltage value) of the electric signal output from the ultrasound transducer <NUM> has a magnitude corresponding to the reception sensitivity in a case where the ultrasound transducer <NUM> receives the ultrasound wave. Here, the reception sensitivity is defined as a ratio of the amplitude of the electric signal, which is output from the ultrasound transducer <NUM> in response to reception of the ultrasound wave, to the amplitude of the ultrasound wave transmitted by the ultrasound transducer <NUM>.

In the present embodiment, by sequentially driving the N ultrasound transducers <NUM> with an electronic switch such as a multiplexer <NUM> (refer to <FIG>), an ultrasound scan occurs in a scanning range along the curved surface on which the ultrasound transducer array <NUM> is disposed, for example, in the range of about several tens of mm from the center of curvature of the curved surface. More specifically, in the case of acquiring a B mode image (tomographic image) as an ultrasound image, a driving voltage is supplied to m (for example, m = N/<NUM>) ultrasound transducers <NUM> (hereinafter, referred to as driving target transducers) arranged in series, among the N ultrasound transducers <NUM>, by opening channel selection of the multiplexer <NUM>. As a result, the m driving target transducers are driven, and an ultrasound wave is output from each driving target transducer of the opening channel. The ultrasound waves output from the m driving target transducers are immediately synthesized, and the composite wave (ultrasound beam) is transmitted to the observation target part. Thereafter, each of the m driving target transducers receives an ultrasound wave (echo) reflected at the observation target part, and outputs an electric signal (reception signal) corresponding to the reception sensitivity at that point in time.

Then, the above-described series of steps (that is, supply of a driving voltage, transmission and reception of ultrasound waves, and output of an electric signal) are repeatedly performed while shifting the position of the driving target transducer, among the N ultrasound transducers <NUM>, one by one (one ultrasound transducer <NUM> at a time). Specifically, the above-described series of steps are started from m driving target transducers on both sides of the ultrasound transducer <NUM> located at one end among the N ultrasound transducers <NUM>. Then, the above-described series of steps are repeated each time the position of the driving target transducer is shifted due to switching of the opening channel by the multiplexer <NUM>. Finally, the above-described series of steps are repeatedly performed a total of N times up to m driving target transducers on both sides of the ultrasound transducer <NUM> located at the other end among the N ultrasound transducers <NUM>.

The backing material layer <NUM> supports each ultrasound transducer <NUM> of the ultrasound transducer array <NUM> from the back surface side. In addition, the backing material layer <NUM> has a function of attenuating ultrasound waves propagating to the backing material layer <NUM> side among ultrasound waves emitted from the ultrasound transducer <NUM> or ultrasound waves (echoes) reflected by the observation target part. The backing material is a material having rigidity, such as hard rubber, and an ultrasound damping material (ferrite, ceramics, and the like) is added as necessary.

The acoustic matching layer <NUM> is superimposed on the ultrasound transducer array <NUM>, and is provided for acoustic impedance matching between the body of the patient and the ultrasound transducer <NUM>. Since the acoustic matching layer <NUM> is provided, it is possible to increase the transmittance of the ultrasound wave. As a material of the acoustic matching layer <NUM>, it is possible to use various organic materials whose acoustic impedance values are closer to that of the human body of the patient than the piezoelectric element of the ultrasound transducer <NUM>. Specific examples of the material of the acoustic matching layer <NUM> include epoxy resin, silicone rubber, polyimide, polyethylene, and the like.

The acoustic lens <NUM> superimposed on the acoustic matching layer <NUM> converges ultrasound waves emitted from the ultrasound transducer array <NUM> toward the observation target part. The acoustic lens <NUM> is formed of, for example, silicon resin (millable silicone rubber (HTV rubber), liquid silicone rubber (RTV rubber), and the like), butadiene resin, and polyurethane resin, and powders of titanium oxide, alumina, silica, and the like are mixed as necessary.

The FPC <NUM> is electrically connected to the electrode of each ultrasound transducer <NUM>. Each of the plurality of coaxial cables <NUM> is wired to the FPC <NUM> at one end thereof. Then, in a case where the ultrasound endoscope <NUM> is connected to the ultrasound processor apparatus <NUM> through the ultrasound connector 32a, each of the plurality of coaxial cables <NUM> is electrically connected to the ultrasound processor apparatus <NUM> at the other end (side opposite to the FPC <NUM>).

In the present embodiment, the ultrasound endoscope <NUM> comprises an endoscope side memory <NUM> (refer to <FIG>). The endoscope side memory <NUM> stores driving times of the plurality of ultrasound transducers <NUM> at the time of ultrasound diagnosis. Strictly speaking, in the endoscope side memory <NUM>, the cumulative driving time of the driving target transducer among the plurality of ultrasound transducers <NUM> is stored.

In the present embodiment, an execution period of ultrasound diagnosis, that is, a period from the start of acquisition of an ultrasound image (moving image) to the end thereof (more specifically, a time during which ultrasound diagnosis is performed in the live mode), is set as the cumulative driving time. However, the invention is not limited thereto, and the time for which the driving voltage is supplied to the driving target transducer may be set as the cumulative driving time.

In a state in which the ultrasound endoscope <NUM> is connected to the ultrasound processor apparatus <NUM>, the CPU <NUM> of the ultrasound processor apparatus <NUM> can access the endoscope side memory <NUM> to read the cumulative driving time stored in the endoscope side memory <NUM>. In addition, the CPU <NUM> of the ultrasound processor apparatus <NUM> rewrites the cumulative driving time stored in the endoscope side memory <NUM> to a default value, or updates the stored cumulative driving time to a new cumulative driving time in a case where the cumulative driving time changes with the execution of ultrasound diagnosis.

The endoscope observation portion <NUM> is a portion provided to acquire an endoscope image, and is disposed on the more proximal side than ultrasound observation portion <NUM> in the distal end portion <NUM> of the insertion part <NUM>. As shown in <FIG> and <FIG>, the endoscope observation portion <NUM> includes the observation window <NUM>, an objective lens <NUM>, the solid-state imaging element <NUM>, the illumination window <NUM>, the cleaning nozzle <NUM>, a wiring cable <NUM>, and the like.

The observation window <NUM> is attached so as to be inclined with respect to the axial direction (longitudinal axis direction of the insertion part <NUM>) at the distal end portion <NUM> of the insertion part <NUM>. Light incident through the observation window <NUM> and reflected at the observation target adjacent part is focused on the imaging surface of the solid-state imaging element <NUM> by the objective lens <NUM>.

The solid-state imaging element <NUM> photoelectrically converts the reflected light of the observation target adjacent part, which is focused on the imaging surface after being transmitted through the observation window <NUM> and the objective lens <NUM>, and outputs an imaging signal. As the solid-state imaging element <NUM>, it is possible to use a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), and the like. The captured image signal output from the solid-state imaging element <NUM> is transmitted to the endoscope processor apparatus <NUM> by the universal cord <NUM> through the wiring cable <NUM> extending from the insertion part <NUM> to the operation unit <NUM>.

The illumination window <NUM> is provided at both side positions of the observation window <NUM>. An exit end of a light guide (not shown) is connected to the illumination window <NUM>. The light guide extends from the insertion part <NUM> to the operation unit <NUM>, and its incidence end is connected to the light source device <NUM> connected through the universal cord <NUM>. The illumination light emitted from the light source device <NUM> is transmitted through the light guide and is emitted from the illumination window <NUM> toward the observation target adjacent part.

The cleaning nozzle <NUM> is an ejection hole formed at the distal end portion <NUM> of the insertion part <NUM> in order to clean the surfaces of the observation window <NUM> and the illumination window <NUM>. From the cleaning nozzle <NUM>, air or cleaning liquid is ejected toward the observation window <NUM> and the illumination window <NUM>. In the present embodiment, the cleaning liquid ejected from the cleaning nozzle <NUM> is water, in particular, degassed water. However, the cleaning liquid is not particularly limited, and other liquids, for example, normal water (water that is not degassed) may be used.

The water supply tank 21a is a tank that stores degassed water, and is connected to the light source connector 32c by an air and water supply tube 34a. Degassed water is used as a cleaning liquid ejected from the cleaning nozzle <NUM>.

The suction pump 21b sucks aspirates (including degassed water supplied for cleaning) inside the body cavity through the treatment tool lead-out port <NUM>. The suction pump 21b is connected to the light source connector 32c by a suction tube 34b. The ultrasound diagnostic apparatus <NUM> may comprise an air supply pump for supplying air to a predetermined air supply destination and the like.

In the insertion part <NUM> and the operation unit <NUM>, the treatment tool channel <NUM> and an air and water supply pipe line (not shown) are provided.

The treatment tool channel <NUM> communicates between a treatment tool insertion port <NUM> and the treatment tool lead-out port <NUM> provided in the operation unit <NUM>. The treatment tool channel <NUM> is connected to a suction button 28b provided in the operation unit <NUM>. The suction button 28b is connected to the suction pump 21b in addition to the treatment tool channel <NUM>.

The air and water supply pipe line communicates with the cleaning nozzle <NUM> at one end side, and is connected to an air and water supply button 28a provided in the operation unit <NUM> at the other end side. The air and water supply button 28a is connected to the water supply tank 21a in addition to the air and water supply pipe line.

The operation unit <NUM> is a unit operated by the operator at the start of ultrasound diagnosis, during diagnosis, at the end of diagnostic, and one end of the universal cord <NUM> is connected to one end of the operation unit <NUM>. As shown in <FIG>, the operation unit <NUM> has the air and water supply button 28a, the suction button 28b, a pair of angle knobs <NUM>, and a treatment tool insertion port (forceps port) <NUM>.

In a case where each of the pair of angle knobs <NUM> is rotated, the bending portion <NUM> is remotely operated to be bent and deformed. By this deformation operation, the distal end portion <NUM> of the insertion part <NUM> in which the ultrasound observation portion <NUM> and the endoscope observation portion <NUM> are provided can be directed in a desired direction.

The treatment tool insertion port <NUM> is a hole formed to insert a treatment tool (not shown), such as forceps, and communicates with the treatment tool lead-out port <NUM> through the treatment tool channel <NUM>. The treatment tool inserted into the treatment tool insertion port <NUM> is introduced into the body cavity from the treatment tool lead-out port <NUM> after passing through the treatment tool channel <NUM>.

The air and water supply button 28a and the suction button 28b are two-stage switching type push buttons, and are operated to switch the opening and closing of the pipe line provided inside each of the insertion part <NUM> and the operation unit <NUM>.

The ultrasound processor apparatus <NUM> causes the ultrasound transducer unit <NUM> to transmit and receive ultrasound waves, and generates an ultrasound image by converting the reception signal, which is output from the ultrasound transducer <NUM> (specifically, a driving target element) at the time of ultrasound wave reception, into an image. In addition, the ultrasound processor apparatus <NUM> displays the generated ultrasound image on the monitor <NUM>.

In the present embodiment, the ultrasound processor apparatus <NUM> supplies a polarization voltage to a polarization target transducer, among the N ultrasound transducers <NUM>, to polarize the polarization target transducer. By performing the polarization processing, the depolarized ultrasound transducer <NUM> can be polarized again by repeating the ultrasound diagnosis. As a result, it is possible to restore the reception sensitivity of the ultrasound transducer <NUM> with respect to ultrasound waves to a satisfactory level.

As shown in <FIG>, the ultrasound processor apparatus <NUM> has the multiplexer <NUM>, the reception circuit <NUM>, the transmission circuit <NUM>, an A/D converter <NUM>, an application specific integrated circuit (ASIC) <NUM>, the cine memory <NUM>, a trigger generation circuit <NUM>, a central processing unit (CPU) <NUM>, and a digital scan converter (DSC) <NUM>.

The reception circuit <NUM> and the transmission circuit <NUM> are electrically connected to the ultrasound transducer array <NUM> of the ultrasound endoscope <NUM>. The multiplexer <NUM> selects a maximum of m driving target transducers from the N ultrasound transducers <NUM>, and opens their channels.

The transmission circuit <NUM> is configured to include a field programmable gate array (FPGA), a pulser (pulse generation circuit <NUM>), a switch (SW), and the like, and is connected to the multiplexer <NUM> (MUX). Instead of the FPGA, an application specific integrated circuit (ASIC) may be used.

The transmission circuit <NUM> is a circuit that supplies a driving voltage for ultrasound wave transmission to the driving target transducers selected by the multiplexer <NUM>, according to the control signal transmitted from the CPU <NUM>, in order to transmit ultrasound waves from the ultrasound transducer unit <NUM>. The driving voltage is a pulsed voltage signal (transmission signal), and is applied to the electrodes of the driving target transducers through the universal cord <NUM> and the coaxial cable <NUM>.

The transmission circuit <NUM> has a pulse generation circuit <NUM> that generates a transmission signal based on a control signal. Under the control of the CPU <NUM>, a transmission signal for driving a plurality of ultrasound transducers <NUM> to generate ultrasound waves is generated using the pulse generation circuit <NUM>, and the generated transmission signal is supplied to the plurality of ultrasound transducers <NUM>. More specifically, under the control of the CPU <NUM>, in the case of performing ultrasound diagnosis, the transmission circuit <NUM> generates a first transmission signal having a driving voltage for performing ultrasound diagnosis using the pulse generation circuit <NUM>. In addition, under the control of the CPU <NUM>, in the case of performing polarization processing, a second transmission signal having a polarization voltage for performing polarization processing is generated using the same pulse generation circuit <NUM> as in the case of generating the first transmission signal.

The magnitude (voltage value or potential) and the supply time of the polarization voltage are set to appropriate values, which satisfy the conditions for obtaining the repolarization effect, by the CPU <NUM> in accordance with the specification of the ultrasound transducer <NUM> (specifically, the thickness and the material of the ultrasound transducer <NUM>) provided in the ultrasound endoscope <NUM> connected to the ultrasound processor apparatus <NUM>. Thereafter, the CPU <NUM> performs polarization processing based on the set values described above.

The reception circuit <NUM> is a circuit that receives an electric signal output from the driving target transducer that has received an ultrasound wave (echo), that is, a reception signal. In addition, according to the control signal transmitted from the CPU <NUM>, the reception circuit <NUM> amplifies the reception signal received from the ultrasound transducer <NUM> and transmits the amplified signal to the A/D converter <NUM>. The A/D converter <NUM> is connected to the reception circuit <NUM>, and converts the reception signal received from the reception circuit <NUM> from an analog signal to a digital signal and outputs the converted digital signal to the ASIC <NUM>.

The ASIC <NUM> is connected to the A/D converter <NUM>. As shown in <FIG>, the ASIC <NUM> forms a phase matching unit <NUM>, a B mode image generation unit <NUM>, a PW mode image generation unit <NUM>, a CF mode image generation unit <NUM>, and a memory controller <NUM>.

In the present embodiment, the above-described functions (specifically, the phase matching unit <NUM>, the B mode image generation unit <NUM>, the PW mode image generation unit <NUM>, the CF mode image generation unit <NUM>, and the memory controller <NUM>) are realized by a hardware circuit, such as the ASIC <NUM>. However, the invention is not limited thereto. The above-described functions may be realized by making the central processing unit (CPU) and software (computer program) for executing various kinds of data processing cooperate with each other.

The phase matching unit <NUM> performs processing for phasing addition (addition after matching the phases of reception data) by giving a delay time to the reception signal (reception data) digitized by the A/D converter <NUM>. By the phasing addition processing, a sound ray signal with narrowed focus of the ultrasound echo is generated.

The B mode image generation unit <NUM>, the PW mode image generation unit <NUM>, and the CF mode image generation unit <NUM> generate an ultrasound image based on the electric signal (strictly speaking, the sound ray signal generated by phasing and adding the reception data) that is output from the driving target transducer among the plurality of ultrasound transducers <NUM> in a case where the ultrasound transducer unit <NUM> receives the ultrasound wave.

The B mode image generation unit <NUM> is an image generation unit that generates a B mode image that is a tomographic image of the inside of the patient (inside of the body cavity). For the sequentially generated sound ray signals, the B mode image generation unit <NUM> corrects the attenuation due to the propagation distance according to the depth of the reflection position of the ultrasound wave by sensitivity time control (STC). The B mode image generation unit <NUM> performs envelope detection processing and logarithm (Log) compression processing on the corrected sound ray signal, thereby generating a B mode image (image signal).

The PW mode image generation unit <NUM> is an image generation unit that generates an image showing the speed of blood flow in a predetermined direction. The PW mode image generation unit <NUM> extracts a frequency component by applying a fast Fourier transform to a plurality of sound ray signals in the same direction among the sound ray signals sequentially generated by the phase matching unit <NUM>. Thereafter, the PW mode image generation unit <NUM> calculates the speed of blood flow from the extracted frequency component, and generates a PW mode image (image signal) showing the calculated speed of blood flow.

The CF mode image generation unit <NUM> is an image generation unit that generates an image showing blood flow information in a predetermined direction. The CF mode image generation unit <NUM> generates an image signal indicating the blood flow information by calculating the autocorrelation between a plurality of sound ray signals in the same direction among the sound ray signals sequentially generated by the phase matching unit <NUM>. Thereafter, based on the image signal described above, the CF mode image generation unit <NUM> generates a CF mode image (image signal) as a color image in which the blood flow information is superimposed on the B mode image signal generated by the B mode image generation unit <NUM>.

The memory controller <NUM> stores the image signal generated by the B mode image generation unit <NUM>, the PW mode image generation unit <NUM>, or the CF mode image generation unit <NUM> in the cine memory <NUM>.

The DSC <NUM> is connected to the ASIC <NUM>, and converts (raster conversion) the signal of the image generated by the B mode image generation unit <NUM>, the PW mode image generation unit <NUM>, or the CF mode image generation unit <NUM> into an image signal according to a normal television signal scanning method, performs various kinds of required image processing, such as gradation processing, on the image signal, and then outputs an obtained signal to the monitor <NUM>.

The cine memory <NUM> has a capacity for storing an image signal for one frame or several frames. The image signal generated by the ASIC <NUM> is output to the DSC <NUM>, and is also stored in the cine memory <NUM> by the memory controller <NUM>. In the freeze mode, the memory controller <NUM> reads the image signal stored in the cine memory <NUM> and outputs the read image signal to the DSC <NUM>. As a result, an ultrasound image (still image) based on the image signal read from the cine memory <NUM> is displayed on the monitor <NUM>.

The trigger generation circuit <NUM> generates a trigger for causing the CPU <NUM> to start polarization processing. The cause of generation of a trigger will be described later.

The CPU <NUM> functions as a controller that controls each unit of the ultrasound processor apparatus <NUM>. The CPU <NUM> is connected to the reception circuit <NUM>, the transmission circuit <NUM>, the A/D converter <NUM>, and the ASIC <NUM> to control these devices. Specifically, the CPU <NUM> is connected to the console <NUM>, and controls each unit of the ultrasound processor apparatus <NUM> according to examination information, control parameters, and the like input through the console <NUM>.

The CPU <NUM> automatically recognizes the ultrasound endoscope <NUM> based on a method, such as Plug and Play (PnP), in a case where the ultrasound endoscope <NUM> is connected to the ultrasound processor apparatus <NUM> through the ultrasound connector 32a. Thereafter, the CPU <NUM> accesses the endoscope side memory <NUM> of the ultrasound endoscope <NUM> to read the cumulative driving time stored in the endoscope side memory <NUM>.

In addition, the CPU <NUM> accesses the endoscope side memory <NUM> at the end of the ultrasound diagnosis, and updates the cumulative driving time stored in the endoscope side memory <NUM> to a value obtained by adding the time required for the ultrasound diagnosis performed immediately before to the cumulative driving time stored in the endoscope side memory <NUM>.

In the present embodiment, the cumulative driving time is stored on the ultrasound endoscope <NUM> side. However, the invention is not limited thereto, and the cumulative driving time may be stored on the ultrasound processor apparatus <NUM> side for each ultrasound endoscope <NUM>.

The CPU <NUM> is connected to the trigger generation circuit <NUM>. In a case where a trigger is given from the trigger generation circuit <NUM>, the CPU <NUM> controls the transmission circuit <NUM> to perform polarization processing in a non-diagnosis period within each frame time during the execution period of ultrasound diagnosis. More specifically, after a trigger is given from the trigger generation circuit <NUM>, during the execution period of the ultrasound diagnosis, in a non-diagnosis period which is a period other than a period for acquiring an image of each frame and during which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are not performed, within each frame time in which an image (still image) of each frame of an ultrasound image (moving image) is acquired, polarization processing is performed on the plurality of ultrasound transducers.

Next, as an operation example of the ultrasound diagnostic apparatus <NUM>, a flow of a series of processes relevant to ultrasound diagnosis (hereinafter, also referred to as diagnostic process) will be described with reference to <FIG>. <FIG> is a diagram showing the flow of the diagnostic process using the ultrasound diagnostic apparatus <NUM>. <FIG> is a diagram showing the procedure of a diagnostic step in the diagnostic process. <FIG> is a diagram showing the flow of the process in the case of performing polarization processing in the diagnostic step and in the case of performing no polarization processing in the diagnostic step.

In a case where each unit of the ultrasound diagnostic apparatus <NUM> is powered on in a state in which the ultrasound endoscope <NUM> is connected to the ultrasound processor apparatus <NUM>, the endoscope processor apparatus <NUM>, and the light source device <NUM>, the diagnostic process starts with the power-ON as a trigger. In the diagnostic process, as shown in <FIG>, an input step is performed first (S001). In the input step, the operator inputs examination information, control parameters, and the like through the console <NUM>. In a case where the input step is completed, a standby step is performed until there is an instruction to start diagnosis (S002). Using the standby step, the CPU <NUM> of the ultrasound processor apparatus <NUM> reads a cumulative driving time from the endoscope side memory <NUM> of the ultrasound endoscope <NUM> (S003).

Then, in a case where there is an instruction to start diagnosis from the operator (Yes in S004), the CPU <NUM> controls each unit of the ultrasound processor apparatus <NUM> to perform a diagnostic step (S005). The diagnostic step proceeds along the flow shown in <FIG>. In a case where the designated image generation mode is the B mode (Yes in S031), each unit of the ultrasound processor apparatus <NUM> is controlled so as to generate a B mode image (S032). In a case where the designated image generation mode is not the B mode (No in S031) but the CF mode (Yes in S033), each unit of the ultrasound processor apparatus <NUM> is controlled so as to generate a CF mode image (S034). In a case where the designated image generation mode is not the CF mode (No in S033) but the PW mode (Yes in S035), each unit of the ultrasound processor apparatus <NUM> is controlled so as to generate a PW mode image (S036). In a case where the designated image generation mode is not the PW mode (No in S035), the process proceeds to step S037.

In each image generation mode, as shown in <FIG>, the trigger generation circuit <NUM> generates a trigger for starting polarization processing, and the trigger is given from the trigger generation circuit <NUM> to the CPU <NUM> (S041).

The CPU <NUM> determines whether or not the trigger has been given from the trigger generation circuit <NUM> (S042).

In a case where no trigger is given to the CPU <NUM> (No in S042), the CPU <NUM> controls each unit of the ultrasound processor apparatus <NUM> so that the normal ultrasound diagnosis is performed. That is, the polarization processing is not performed during the execution period of the ultrasound diagnosis (S043).

On the other hand, in a case where a trigger is given to the CPU <NUM> (Yes in S042), the CPU <NUM> controls each unit of the ultrasound processor apparatus <NUM> so that polarization processing is performed on the plurality of ultrasound transducers <NUM> in a non-diagnosis period, which is a period other than a period for acquiring an image of each frame and during which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are not performed, within each frame time in which an image of each frame of an ultrasound image is acquired during the execution period of the ultrasound diagnosis after the trigger is given. That is, the polarization processing is performed during the execution period of the ultrasound diagnosis (S044).

Then, returning to <FIG>, the CPU <NUM> determines whether or not the ultrasound diagnosis has ended (S037). In a case where the ultrasound diagnosis has not ended (No in S037), the process returns to the diagnostic step S031, and the generation of an ultrasound image in each image generation mode is repeatedly performed until the diagnosis end conditions are satisfied. As the diagnosis end conditions, for example, the operator gives an instruction to end the diagnosis through the console <NUM>.

On the other hand, in a case where the diagnosis end conditions are satisfied and accordingly the ultrasound diagnosis ends (Yes in S037), the CPU <NUM> adds the time required for the ultrasound diagnosis performed so far to the cumulative driving time read out from the endoscope side memory <NUM> in step S003, and updates the cumulative driving time stored in the endoscope side memory <NUM> to the cumulative driving time after the addition (S038). The diagnostic step ends at a point in time at which the series of steps (steps S031 to S038) in the diagnostic step end.

Then, returning to <FIG>, the diagnostic process ends at a point in time at which each unit of the ultrasound diagnostic apparatus <NUM> is powered off (Yes in S006). On the other hand, in a case where the power of each unit of the ultrasound diagnostic apparatus <NUM> is maintained in the ON state (No in S006), the process returns to the input step S001, and each step of the diagnostic process described above is repeated.

Next, the scanning timing of a scanning line (line) scanned by electronic sector scanning in the case of performing ultrasound diagnosis will be described.

<FIG> is a conceptual diagram of an example showing the scanning timings of a plurality of scanning lines scanned by electronic sector scanning during the execution period of ultrasound diagnosis. In <FIG>, the vertical axis indicates a voltage of a pulse (transmission pulse) of a transmission signal for generating an ultrasound wave for scanning a scanning line, and the horizontal axis indicates the passage of time.

In the present embodiment, it is assumed that the total number of plural ultrasound transducers <NUM> (the number of elements) is N = <NUM> and the total number of scanning lines (lines) within each frame time, in which an image (still image) of each frame of an ultrasound image (moving image) is acquired, is <NUM> lines from a scanning line Line1 on the right end side to a scanning line Line128 on the left end side as shown in <FIG>. In addition, it is assumed that the number of ultrasound transducers <NUM> (the number of opening channels) simultaneously driven to form an ultrasound beam at the time of ultrasound diagnosis is m = <NUM>.

A plurality of scanning lines Line1 to Line128 are scanned by electronic sector scanning for acquiring an image of one frame of an ultrasound image, and an ultrasound beam for scanning an image of each line of the ultrasound image is expressed as a virtual line.

In the case of performing ultrasound diagnosis, as shown in <FIG>, during the execution period of the ultrasound diagnosis, that is, during a period from the start of acquisition of an ultrasound image (moving image) to the end of the acquisition, scanning of the scanning lines Line1 to Line128 is sequentially performed within each frame time in which an image of each frame of an ultrasound image is acquired. That is, a transmission signal (first transmission signal) having a driving voltage for performing ultrasound diagnosis is supplied from the transmission circuit <NUM> to the driving target transducer for performing ultrasound diagnosis.

Within each frame time, a period during which an ultrasound image is acquired is a period during which scanning of the scanning lines Line1 to Line128 is performed. In addition, a non-diagnosis period is a period from the end of scanning of the scanning line Line128 to the end of each frame time.

In the example shown in <FIG>, between the end of scanning of the last scanning line Line128 within one frame time and the start of scanning of the first scanning line Line1 within the next one frame time, a non-diagnosis period is provided in which transmission of ultrasound waves and reception of reflected waves (echoes) of ultrasound waves for performing ultrasound diagnosis are not performed. In the case of the present embodiment, the non-diagnosis period is provided. However, the non-diagnosis period may not be provided depending on the system.

Next, the timing of supplying a transmission signal for performing polarization processing in the case of performing the polarization processing during the execution period of ultrasound diagnosis will be described.

<FIG> is a conceptual diagram of an example showing the timing of scanning a scanning line and the timing of supplying a transmission signal for performing polarization processing in the case of performing polarization processing during the execution period of ultrasound diagnosis.

In the case of performing polarization processing, as shown in <FIG>, within each frame time, scanning of the scanning lines Line1 to Line128 for performing ultrasound diagnosis is sequentially performed as in the case shown in <FIG>. Then, within each frame time, polarization processing is performed in a non-diagnosis period after the end of the scanning of the last scanning line Line128. That is, a transmission signal (second transmission signal) having a polarization voltage for performing polarization processing is supplied from the transmission circuit <NUM> to the polarization target transducer that performs polarization processing.

In the case of the present embodiment, two transmission signals for polarization processing called polarization processing <NUM> and <NUM> are supplied as transmission signals for performing polarization processing. As described above, the total number of plural ultrasound transducers <NUM> is <NUM>, and the number of opening channels is <NUM> that is the half of <NUM>. Therefore, a transmission signal of polarization processing <NUM> is supplied to the <NUM> ultrasound transducers <NUM>, which are the half of the <NUM> ultrasound transducers <NUM>, and then a transmission signal of polarization processing <NUM> is supplied to the <NUM> ultrasound transducers <NUM>, which are the remaining half.

In the case of the present embodiment, since a non-diagnosis period is provided within each frame time, it is possible to perform polarization processing without lowering the frame rate by supplying a transmission signal for performing polarization processing within the non-diagnosis period.

The polarization processing can be performed in a period other than a period for acquiring an ultrasound image, that is, in a period before the first scanning line Line1 is scanned and after the last scanning line Line128 is scanned.

On the other hand, in a case where a non-diagnosis period is not provided within each frame time, a transmission signal for performing polarization processing may be supplied by lowering the frame rate intentionally within a range in which there is no influence on the image quality of the ultrasound image. This is because it is considered that it would be acceptable to lower the image quality of an image (part of a moving image) by temporarily lowering the frame rate rather than lowering the image quality of the entire image (entire moving image) by lowering the reception sensitivity of the ultrasound transducer <NUM>.

Alternatively, it is also possible to generate a non-diagnosis period during which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are not performed, within each frame time during the execution period of ultrasound diagnosis, by reducing at least one of the line density, the number of lines, or the line interval of a plurality of scanning lines scanned by electronic sector scanning for performing ultrasound diagnosis and perform polarization processing while maintaining the frame rate within the generated non-diagnosis period.

Here, the line density indicates a ratio of the number of scanning lines scanned within one frame time to the total number of scanning lines within one frame time. The number of lines indicates the number of scanning lines scanned within one frame time among a plurality of scanning lines within one frame time. The line interval indicates an interval of time from the scanning of one scanning line among a plurality of scanning lines within one frame time to the scanning of the next scanning line.

<FIG> is a conceptual diagram of an example showing the timing of supplying a transmission signal for performing polarization processing in a case where the line density of scanning lines for performing ultrasound diagnosis is reduced.

In this case, as shown in <FIG>, within each frame time, scanning of the even-numbered <NUM> scanning lines Line2, Line4,. , and Line128 is omitted, and scanning of the odd-numbered <NUM> scanning lines Line1, Line3,. , and Line127 is sequentially performed. Then, within each frame time, after the end of the scanning of the last scanning line Line127, in a non-diagnosis period generated by omitting the scanning of the even-numbered <NUM> scanning lines Line2, Line4,. , and Line128, polarization processing is performed as in the case of <FIG>.

In this manner, since a non-diagnosis period can be generated within each frame time by reducing the line density of scanning lines for performing ultrasound diagnosis, it is possible to perform the polarization processing within the generated non-diagnosis period while maintaining the frame rate.

The scanning of the odd-numbered <NUM> scanning lines Line1, Line3,. , and Line <NUM> may be omitted, and only the scanning of the even-numbered <NUM> scanning lines Line2, Line4,. , and Line <NUM> may be performed. In addition, the scanning of the next one or more scanning lines may be omitted each time one or more scanning lines are scanned. For example, the scanning of the next one scanning line is omitted each time two scanning lines are scanned. In the case of reducing the line density of the scanning lines, the rate of reducing the line density of the scanning lines can be appropriately determined according to the image quality of the ultrasound image, the time required to perform polarization processing, and the like.

Subsequently, <FIG> is a conceptual diagram of an example showing the timing of supplying a transmission signal for performing polarization processing in a case where the number of scanning lines for performing ultrasound diagnosis is reduced.

In this case, as shown in <FIG>, within each frame time, scanning of the nine scanning lines Line1 to Line9 on the right end portion side and the ten scanning lines Line119 to Line128 on the left end portion side is omitted, and the scanning of the <NUM> scanning lines Line10 to Line118 at the central portion is sequentially performed. Then, within each frame time, after the end of the scanning of the last scanning line Line118, in a non-diagnosis period generated by omitting the scanning of the scanning lines Line1 to Line9 and the scanning lines Line119 to Line128, polarization processing is performed as in the case of <FIG>.

In this manner, since a non-diagnosis period can be generated within each frame time by reducing the number of scanning lines for performing ultrasound diagnosis, it is possible to perform the polarization processing within the generated non-diagnosis period while maintaining the frame rate.

Within each frame time, it is not essential to omit the scanning of the scanning lines at both end portions, and only the scanning of the scanning line at one end portion may be omitted. In the case of reducing the number of scanning lines, the number of scanning lines to be reduced can be appropriately determined according to the time required to perform polarization processing and the like. In addition, in the case of reducing the number of scanning lines, it is preferable to omit scanning of scanning lines sequentially from the end portion side rather than omitting scanning of scanning lines at the central portion in order to prevent the image quality of the ultrasound image from lowering.

Subsequently, <FIG> is a conceptual diagram of an example showing the timing of supplying a transmission signal for performing polarization processing in a case where the line interval of scanning lines for performing ultrasound diagnosis is reduced.

In this case, as shown from a state shown on the upper side to a state shown on the lower side in <FIG>, within each frame time, the line interval between the scanning lines Line1 to Line128 (time interval between two adjacent scanning lines) is reduced (narrowed), and the scanning of the scanning lines Line1 to Line128 is sequentially performed. Then, within each frame time, after the end of the scanning of the last scanning line Line128, in a non-diagnosis period generated by reducing the line interval between the scanning lines Line1 to Line128, polarization processing is performed as in the case of <FIG>.

The line interval between the scanning lines is generally determined according to the time from transmission of the ultrasound wave to reception of the reflected wave or the like. In a case where the line interval between the scanning lines is reduced too much, the acquired ultrasound image may be adversely affected. However, for the line interval between the scanning lines, a margin time is usually set in addition to the time from transmission of the ultrasound wave to reception of the reflected wave. Therefore, within the range of the margin time, it is possible to reduce the line interval between the scanning lines without lowering the image quality of the ultrasound image.

In this manner, since a non-diagnosis period can be generated within each frame time by reducing the line interval between the scanning lines for performing ultrasound diagnosis, it is possible to perform the polarization processing within the generated non-diagnosis period while maintaining the frame rate.

In the case of reducing the line interval between the scanning lines within each frame time, the time for which the line interval between the scanning lines is to be reduced can be appropriately determined according to the time required to perform the polarization processing and the like within the range in which the line interval between the scanning lines can be reduced.

In addition, in the case of performing ultrasound diagnosis, the number of times of driving of the ultrasound transducer <NUM> disposed at the central portion is larger than that on the end portion side. Therefore, the ultrasound transducer <NUM> disposed at the central portion has a higher risk of depolarization than that disposed on the end portion side.

In the case of the present embodiment, the number of opening channels is <NUM>. Therefore, in the case of scanning the scanning line Line64 at the central portion, <NUM> ultrasound transducers <NUM> on both sides of the ultrasound transducer <NUM> at the central portion, for example, a total of <NUM> ultrasound transducers <NUM> including <NUM> ultrasound transducers <NUM> on the left end portion side from the ultrasound transducer <NUM> at the central portion and <NUM> ultrasound transducers <NUM> on the right end portion side from the ultrasound transducer <NUM> adjacent rightward to the ultrasound transducer <NUM> at the central portion are simultaneously driven. The same applies to the case of scanning the other scanning lines Line33 to Line96 at the central portion.

On the other hand, in the case of scanning the scanning line Line1 at the right end portion, since the number of opening channels is <NUM> but there is no ultrasound transducer <NUM> on the further right side of the ultrasound transducer <NUM> at the right end portion, only the <NUM> ultrasound transducers <NUM> on the central portion side from the ultrasound transducer <NUM> at the right end portion are simultaneously driven.

In the case of scanning the second scanning line from the right end, only one ultrasound transducer <NUM> at the right end portion is present on the right side of the second ultrasound transducer <NUM> from the right end. Therefore, a total of only <NUM> ultrasound transducers <NUM> including the <NUM> ultrasound transducers <NUM> on the central portion side from the second ultrasound transducer <NUM> from the right end and one ultrasound transducer <NUM> at the right end portion are simultaneously driven.

The same applies to the case of scanning the third to 32nd scanning lines Line3 to Line32 from the right end, and only a total of <NUM> to <NUM> ultrasound transducers <NUM> are simultaneously driven. In addition, the same applies to the case of scanning the scanning lines Line97 to Line128 on the left end portion side. Therefore, within each frame time, it is desirable to make the time for performing polarization processing on the ultrasound transducer <NUM> disposed at the central portion longer than the time for performing polarization processing on the ultrasound transducers <NUM> disposed at both end portions.

Next, the timing of supplying a transmission signal for making the time for performing polarization processing on the ultrasound transducer <NUM> disposed at the central portion longer than the time for performing polarization processing on the ultrasound transducers <NUM> disposed at both end portions in the case of performing the polarization processing during the execution period of ultrasound diagnosis will be described.

<FIG> is a conceptual diagram of an example showing the timing of supplying a transmission signal for making the time for performing polarization processing on the ultrasound transducer disposed at the central portion longer than the time for performing polarization processing on the ultrasound transducers disposed at both end portions in the case of performing the polarization processing during the execution period of ultrasound diagnosis.

In this case, as shown in <FIG>, within each frame time, scanning of the scanning lines Line1 to Line128 for performing ultrasound diagnosis is sequentially performed as in the case shown in <FIG>. Then, in a non-diagnosis period after the end of scanning of the last scanning line Line128 within each frame time, as shown in <FIG>, polarization processing on the <NUM> ultrasound transducers <NUM> in the central portion and polarization processing on the <NUM> ultrasound transducers <NUM> at both end portions including the <NUM> ultrasound transducers <NUM> at the right end portion and the <NUM> ultrasound transducers <NUM> at the left end portion are separately performed.

In the case of the present embodiment, three transmission signals called polarization processing <NUM> to <NUM> are supplied as transmission signals for performing polarization processing. A transmission signal of polarization processing <NUM> is supplied to a total of <NUM> ultrasound transducers <NUM> including the <NUM> ultrasound transducers <NUM> at the right end portion and the <NUM> ultrasound transducers <NUM> at the left end portion, among the <NUM> ultrasound transducers <NUM>, and then transmission signals of polarization processing <NUM> and <NUM> are supplied to the <NUM> ultrasound transducers <NUM> at the central portion.

That is, within each frame time, the polarization processing is performed once on the <NUM> ultrasound transducers <NUM> at both end portions, while the polarization processing is performed twice on the <NUM> ultrasound transducers <NUM> at the central portion. As a result, with respect to the <NUM> ultrasound transducers <NUM> at the central portion having a higher risk of depolarization than the <NUM> ultrasound transducers <NUM> at both end portions, the polarization processing can be performed twice as long as the <NUM> ultrasound transducers <NUM> at both end portions.

In addition, the time for performing the polarization processing on the ultrasound transducers <NUM> disposed at the central portion may be made to be longer than that on the ultrasound transducers <NUM> disposed at both end portions. For example, the time of polarization processing performed on the <NUM> ultrasound transducers <NUM> at the central portion may be twice the time of polarization processing performed on the <NUM> ultrasound transducers <NUM> at both end portions or longer.

Next, a trigger generation timing, that is, a timing for starting polarization processing will be described.

Depolarization of the ultrasound transducer <NUM> progresses as dipoles applied to both sides of the ultrasound transducer <NUM> decrease according to the time for which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are performed, that is, according to the cumulative driving time of the plurality of ultrasound transducers <NUM>.

The trigger generation circuit <NUM> cannot directly determine whether or not the ultrasound transducer <NUM> is depolarized. Accordingly, for example, the trigger generation circuit <NUM> can determine whether or not the ultrasound transducer <NUM> is depolarized based on the above-described cumulative driving time of the ultrasound transducers <NUM> and generate a trigger in a case where the cumulative driving time of the plurality of ultrasound transducers <NUM> for performing ultrasound diagnosis becomes equal to or longer a specified time.

As the specified time, a default value of the time may be set in the trigger generation circuit <NUM>, or any time may be set according to the user's instruction. The specified time is any time, and may be on the order of several hours or on the order of several frame times.

The trigger generation circuit <NUM> can generate a trigger in a case where a button for giving an instruction to start polarization processing is pressed according to the user's instruction. That is, the polarization processing can be started at any timing according to the user's instruction.

The button may be an electronic button displayed within the touch panel of the console <NUM>, or may be a mechanical button provided on the operation unit <NUM> of the ultrasound endoscope <NUM>.

In addition, the trigger generation circuit <NUM> can generate a trigger in a case where the ultrasound image generation mode is set to the contrast mode in which a contrast image acquired using a contrast medium is highlighted. In the contrast mode, the ultrasound wave transmitted from the ultrasound transducer <NUM> is generally set to have a low output that does not destroy bubbles contained in the contrast medium. Therefore, since the S/N ratio of the image is reduced, an adverse effect of sensitivity lowering due to depolarization is likely to appear.

In a case where the depolarization of the ultrasound transducer <NUM> progresses and its reception sensitivity lowers, an ultrasound image acquired at a position where the display depth is relatively large is likely to have a lower S/N ratio than an ultrasound image acquired at a position where the display depth is relatively small, and the image quality is easily degraded. For this reason, the trigger generation circuit <NUM> can generate a trigger in a case where the display depth of the ultrasound image for performing ultrasound diagnosis is set to a predetermined depth or more.

The display depth of the ultrasound image for performing ultrasound diagnosis can be set to, for example, a position of <NUM> in depth and a position of <NUM> in depth according to the user's instruction. For example, assuming that the predetermined depth described above is set to <NUM>, the trigger generation circuit <NUM> does not generate a trigger in a case where the display depth of the ultrasound image is set to a position of <NUM> in depth, and generates a trigger in a case where the display depth of the ultrasound image is set to a position of <NUM> in depth.

As the predetermined depth, a default value of the depth may be set in the trigger generation circuit <NUM>, or any depth may be set according to the user's instruction.

Similarly, in a case where the depolarization of the ultrasound transducer <NUM> progresses and its reception sensitivity lowers, a B mode ultrasound image acquired at a position where the display depth is relatively large is likely to have a lower brightness than a B mode ultrasound image acquired at a position where the display depth is relatively small. For this reason, the trigger generation circuit <NUM> can generate a trigger in a case where the brightness of the B mode ultrasound image, which is acquired in a state in which the display depth is set to a predetermined depth or more, is equal to or less than a predetermined brightness.

As the predetermined brightness, a default value of the brightness may be set in the trigger generation circuit <NUM>, or any brightness may be set according to the user's instruction.

In addition, by analyzing the ultrasound image during the execution period of the ultrasound diagnosis, it is possible to recognize that the user is performing treatment while viewing the ultrasound image. For example, it is possible to recognize whether or not the user is in the process of insertion, whether or not the stent is being released, or whether or not <NUM> minutes has passed from the start of acquisition of the ultrasound image. In this case, since other images, such as an X-ray fluoroscopic image and an endoscope image, are used together with the ultrasound image during the treatment, the user does not view the details of the ultrasound image in many cases. Therefore, it is possible to appropriately perform the polarization processing regardless of the image quality. For this reason, the trigger generation circuit <NUM> can generate a trigger in a case where it is recognized that the user is performing treatment while viewing the ultrasound image based on the ultrasound image.

The ultrasound diagnostic apparatus <NUM> can acquire an ultrasound image and an endoscope image and display the ultrasound image and the endoscope image on the monitor <NUM> in various display modes.

As shown in <FIG>, the display modes include a first display mode in which only an ultrasound image is displayed, a second display mode in which an ultrasound image is displayed so as to be larger than an endoscope image by using picture in picture (PinP), a third display mode in which an ultrasound image is displayed so as to be smaller than an endoscope image by using the PinP similarly, and a fourth display mode in which only an endoscope image is displayed. The first to fourth display modes can be freely switched and displayed according to the user's instruction.

Here, in the third display mode, since the ultrasound image is displayed so as to be smaller than the endoscope image, it is possible to appropriately perform the polarization processing regardless of the image quality. For this reason, the trigger generation circuit <NUM> can generate a trigger in a case where the ultrasound image is displayed so as to be smaller than the endoscope image by the picture in picture in the third display mode.

Although the trigger generation factors have been exemplified, the trigger may be generated based on any factor other than the above-described factors.

As the end conditions of the polarization processing, for example, a case where the cumulative processing time of the polarization processing reaches a predetermined time, a case where the user gives an instruction to end the polarization processing, a case where the contrast mode is changed to another ultrasound image generation mode, a case where the display depth of the ultrasound wave for performing ultrasound diagnosis is set to be smaller than a predetermined depth, a case where it is not recognized whether or not the user is performing treatment based on the endoscope image, a case where the brightness of the B mode ultrasound image acquired at a position where the display depth of the ultrasound wave is relatively large becomes larger than a predetermined brightness, and a case where the third display mode is changed to another display mode can be considered. However, the polarization processing may be ended according to end conditions other than those described above.

The ultrasound diagnostic apparatus <NUM> performs polarization processing in a non-diagnosis period, which is a period other than the acquisition period of an image of each frame and during which transmission of ultrasound waves and reception of reflected waves for performing ultrasound diagnosis are not performed, within each frame time during the execution period of ultrasound diagnosis. Therefore, even during the execution period of the ultrasound diagnosis, the frame rate is not reduced. As a result, since the reception sensitivities of the plurality of ultrasound transducers <NUM> can always be kept satisfactory without reducing the image quality of the ultrasound image, a high-quality ultrasound image can always be acquired.

In addition, since the ultrasound diagnostic apparatus <NUM> performs the polarization processing using the existing transmission circuit <NUM>, more specifically, the pulse generation circuit <NUM>, it is possible to perform the polarization processing during the execution period of the ultrasound diagnosis without significantly changing the existing circuit.

The total number of ultrasound transducers <NUM> and the number of opening channels may be changed to any number. For example, in a case where the number of opening channels is the same as the total number of ultrasound transducers <NUM>, one transmission signal for polarization processing for driving the <NUM> ultrasound transducers <NUM> can also be supplied instead of the two transmission signals for polarization processing called the above-described polarization processing <NUM> and <NUM>. Alternatively, in a case where the number of opening channels is <NUM>/<NUM> of the total number of ultrasound transducers <NUM>, four transmission signals for polarization processing called polarization processing <NUM> to <NUM> for driving the <NUM> ultrasound transducers <NUM> can also be supplied.

The polarization processing may be performed by combining the case of reducing the line density of scanning lines, the case of reducing the number of scanning lines, and the case of reducing the line interval of scanning lines. Alternatively, it is also possible to perform the polarization processing by combining the case of reducing at least one of the line density of scanning lines, the number of scanning lines, or the line interval of scanning lines and the case of making the time for performing the polarization processing on the ultrasound transducer <NUM> disposed at the central portion longer than the time for performing the polarization processing on the ultrasound transducers <NUM> disposed at both end portions. Other than the above, the characteristics of the above respective embodiments may be implemented in combination.

The transmission circuit <NUM> may generate the first transmission signal using the first pulse generation circuit and generate the second transmission signal using the second pulse generation circuit. That is, the first transmission signal and the second transmission signal may be generated using different pulse generation circuits. Alternatively, the first transmission signal may be generated by the transmission circuit <NUM>, and a polarization circuit different from the transmission circuit <NUM> may be provided and the second transmission signal may be generated using the polarization circuit. That is, a dedicated circuit for polarization processing may be provided.

Claim 1:
An operation method of an ultrasound diagnostic apparatus (<NUM>), comprising:
generating an ultrasound image by transmitting ultrasound waves using a plurality of ultrasound transducers (<NUM>) and receiving reflected waves of the ultrasound waves at a time of performing an ultrasound diagnosis; and
applying a polarization processing to the ultrasound transducers (<NUM>),
wherein applying the polarization processing is separate from generating the ultrasound image,
characterized in that
in generating the ultrasound image, the polarization processing is applied to the ultrasound transducers (<NUM>) after acquisition of an image of one frame of the ultrasound image, within each frame time in which an image of each frame of the ultrasound image is acquired, and in a non-diagnosis period before acquisition of an image of a next one frame.