JP7559569B2 - Ultrasound probe, ultrasound diagnostic device and program - Google Patents

Description

The present invention relates to an ultrasound probe, an ultrasound diagnostic device, and a program.

Conventionally, ultrasound diagnostic devices have been widely used to examine the inside of a test object by irradiating the inside of the object with ultrasound and receiving and analyzing the reflected waves. Because ultrasound diagnostic devices can examine a test object non-destructively and non-invasively, they are widely used for a variety of purposes, including medical examinations and the inspection of the inside of building structures.

In an ultrasound diagnostic device, multiple transducers (acoustic elements, converters) that convert between voltage signals and ultrasonic vibrations are arranged in a specific direction (azimuth direction, scanning direction) in an ultrasound probe, and these transducer arrays (transducer sections) emit ultrasonic waves when a driving voltage is applied. The ultrasound diagnostic device can acquire two-dimensional ultrasound image data almost in real time by temporally varying (scanning) the transducers that detect voltage changes due to the incidence of reflected ultrasonic waves.

Furthermore, there is technology that can acquire three-dimensional ultrasound image data in almost real time by moving (oscillating) the array of these transducers back and forth perpendicular to the scanning direction within the ultrasound incidence and exit plane. By acquiring three-dimensional images using such technology, users can more easily grasp the three-dimensional shape and positional relationships of the object of examination, which are difficult to understand from two-dimensional images.

Stepping motors are often used as a means of vibrating transducer arrays. The reason is that even with excessive torque, the excitation can be varied at a constant speed using constant current control, meaning that the stepping motor shaft can be rotated at a constant speed by inputting pulses at regular intervals, and since it can be stopped at an accurate position when driven in pulse units, a position detection unit (encoder) is not required. Also, when the number of pulses does not provide sufficient angular resolution, a microstep drive method is commonly used in which one pulse is electrically broken down and driven. However, while there is no loss of synchronism in pulse units if there is sufficient torque, meaning that the position is accurate, when viewed in microstep (electrical angle) step units, the accuracy decreases.

When oscillating at high speed, there is no problem because there is sufficient acceleration, but when oscillating at low speed (1 rpm or less), the following problems occur. The value of low speed here means a speed that is sufficiently slower than the oscillation speed corresponding to the maximum self-starting frequency that does not require acceleration and deceleration (less than 1/2 the oscillation speed corresponding to the maximum self-starting frequency). At frequencies above the maximum self-starting frequency, the motor is driven using trapezoidal drive (acceleration, constant speed, deceleration) to avoid the effects of step-out and overshoot. At frequencies below the maximum self-starting frequency, the motor is oscillated at the target oscillation speed from the beginning without setting an acceleration time. In order to quickly display a stable ultrasound image, it is better to keep the acceleration and deceleration time, which makes the oscillation unstable, as short as possible. However, when driving at low speed, the speed fluctuation due to the effect of detent torque (magnetic attraction force in a non-excited state acting between the rotor and stator) is relatively large compared to the target oscillation speed, so in some cases, even if acceleration and deceleration time is required to avoid this effect, the stepping motor can be rotated at high speed by inserting gears into the oscillation mechanism. Therefore, the range of low speed depends on the oscillation mechanism.

At low speeds, the oscillation starts without accelerating, but if the oscillation speed is sufficiently slower than the oscillation speed corresponding to the maximum automatic startup frequency, the time it takes to start moving varies depending on the position where it stopped when the oscillation started, and the slower the speed, the more noticeable this time becomes. If the oscillation starts from an unstable point (a microstep unit position other than a pulse unit position), it depends on the distance from the stable points (pulse unit positions) on both sides, and in the worst case, reversal may occur. When the oscillation starts from a stable point, even if an input step is sent, it does not start moving immediately, so if position information is formed based on the input step, the ultrasound image will be stretched or the image update will be delayed.

Therefore, there is known a document transport device and an image forming device that suppresses step-out and vibration by changing the drive current value when starting up, switching the rotation direction, or decelerating (see Patent Document 1).

The advantage of the method in Patent Document 1 is that by reducing the current value at startup, the force (motor torque) that attracts the motor to a stable point is weakened, allowing the motor to start a constant oscillation without overshooting or vibration. Broadly speaking, this method achieves stable document transport by varying the current value of the stepping motor drive for each situation. Another commonly used method is to mount an encoder and use feedback control to vary the drive current from the encoder value.

Patent No. 4926465

Increasing the drive current also increases heat generation, and in particular in types where the drive circuit is built into the ultrasonic probe connector, the heat generation causes the temperature of the surface of the ultrasonic probe connector that people touch to rise. For this reason, the drive current is kept low even during steady-speed rotation, and as in Patent Document 1, if the current is reduced any further at startup, the drive torque will be insufficient and the motor will not rotate, resulting in loss of synchronization. Patent Document 1 states that the force (motor torque) that attracts the motor to the stable point is weakened by reducing the current value at startup, but detent torque (magnetic attraction force in a non-excited state that works between the rotor and stator) is a force that occurs even when no current is flowing, and in order to avoid this effect, it is necessary to increase the current value instead. Furthermore, Patent Document 1 states that the effect of the force that attracts the motor to the stable point can be avoided by adopting microstep drive, but at low speeds, the speed fluctuations caused by this effect are relatively noticeable even with microstep drive.

The same problem occurs when an encoder is installed and the drive current is varied by feedback control. Also, a highly accurate encoder is required to achieve feedback control, which halves the benefits of using a stepping motor.

The objective of the present invention is to properly initiate oscillation of the vibrator section while suppressing heat generation.

In order to solve the above problems, the ultrasonic probe of the present invention according to claim 1 comprises:
A transducer unit for transmitting and receiving ultrasonic waves;
an oscillation mechanism for oscillating the oscillator unit by microstep drive;
A drive circuit unit that drives the swing mechanism unit;
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit ,
The period smaller than the period corresponding to the target rocking speed is greater than the period corresponding to the maximum self-starting frequency .

The invention according to claim 2 provides the ultrasonic probe according to claim 1,
a position detection unit that detects position information of the transducer unit,
The predetermined timing is a timing at which the detected position information of the transducer portion changes from the start of the oscillation.

The invention according to claim 3 provides the ultrasonic probe according to claim 2,
The position detection unit is a magnetic encoder.

The invention according to claim 4 provides the ultrasonic probe according to any one of claims 1 to 3,
The oscillation control unit determines whether the target oscillation speed is equal to or lower than a predetermined speed, and if it is equal to or lower than the predetermined speed, sets the frequency of the microsteps to a period smaller than the period corresponding to the target oscillation speed from the start of oscillation of the vibrator unit to the predetermined timing, and after the predetermined timing, sets the period of the microsteps to the period corresponding to the target oscillation speed to control the drive circuit unit.

The invention according to claim 5 provides the ultrasonic probe according to any one of claims 1 to 4 ,
The period smaller than the period corresponding to the target rocking speed is a period corresponding to twice the target rocking speed.

The invention described in claim 6 is the ultrasonic probe described in any one of claims 1 to 5 ,
A connector for connecting to the ultrasound diagnostic device body is provided.
The connector portion includes the drive circuit portion and the swing control portion.

The ultrasonic diagnostic apparatus according to the seventh aspect of the present invention comprises:
An ultrasonic probe according to any one of claims 1 to 6 ;
and an ultrasonic diagnostic device body having an image generating unit that generates ultrasonic image data based on the reception signal obtained by the ultrasonic probe.

The ultrasonic diagnostic apparatus according to the eighth aspect of the present invention comprises:
A transducer unit for transmitting and receiving ultrasonic waves;
an ultrasonic probe including a swing mechanism that swings the transducer unit by microstep drive;
A drive circuit unit that drives the swing mechanism unit;
an image generating unit that generates ultrasound image data based on a reception signal obtained by the ultrasound probe;
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit ,
The period smaller than the period corresponding to the target rocking speed is greater than the period corresponding to the maximum self-starting frequency .

The invention according to claim 9 provides the ultrasonic diagnostic apparatus according to claim 8 ,
The ultrasonic probe includes:
a position detection unit that detects position information of the transducer unit,
The predetermined timing is a timing at which the detected position information of the transducer portion changes from the start of the oscillation.

The invention according to claim 10 provides the ultrasonic diagnostic apparatus according to claim 9 ,
The position detection unit is a magnetic encoder.

The invention according to claim 11 provides the ultrasonic diagnostic apparatus according to any one of claims 8 to 10 ,
The oscillation control unit determines whether the target oscillation speed is equal to or lower than a predetermined speed, and if it is equal to or lower than the predetermined speed, sets the frequency of the microsteps to a period smaller than the period corresponding to the target oscillation speed from the start of oscillation of the vibrator unit to the predetermined timing, and after the predetermined timing, sets the period of the microsteps to the period corresponding to the target oscillation speed to control the drive circuit unit.

The invention according to claim 12 provides the ultrasonic diagnostic apparatus according to any one of claims 8 to 11 ,
The period smaller than the period corresponding to the target rocking speed is a period corresponding to twice the target rocking speed.

The program of the invention according to claim 13 ,
A transducer unit for transmitting and receiving ultrasonic waves;
an oscillation mechanism for oscillating the oscillator unit by microstep drive;
A drive circuit unit that drives the rocking mechanism unit.
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit;
Function as a
The period smaller than the period corresponding to the target rocking speed is greater than the period corresponding to the maximum self-starting frequency .

According to the present invention, the vibrator part can start to oscillate appropriately while suppressing heat generation.

1 is a block diagram showing a functional configuration of an ultrasound diagnostic apparatus according to an embodiment of the present invention; 1A is a diagram showing a schematic configuration of a stepping motor, and FIG. 1B is a diagram showing a drive current of the stepping motor for micro steps. 1A is a diagram showing a step operation in pulse units of a stepping motor, FIG. 1B is a diagram showing a step operation in microstep units of a stepping motor, and FIG. 1C is a diagram showing the relationship between pulse units and microstep units of a stepping motor. FIG. 2 is a schematic cross-sectional perspective view of an ultrasonic probe body. FIG. 2 is a circuit diagram of a drive circuit unit. 13 is a flowchart showing a transducer array swinging process. 13 is a diagram showing the encoder value of the position detection unit, the microstep output, and the actual oscillation speed when the period is set to twice the target oscillation speed at the start of oscillation. FIG. 13 is a diagram showing the encoder value of the position detector, the microstep output, and the actual oscillation speed when a period corresponding to the maximum self-start frequency is set at the start of oscillation. FIG. FIG. 13 is a block diagram showing the functional configuration of a modified ultrasonic diagnostic apparatus.

The following describes in detail the embodiments and modifications of the present invention with reference to the accompanying drawings. Note that the present invention is not limited to the illustrated examples.

(Embodiment)
An embodiment of the present invention will be described with reference to Figs. 1 to 8. First, the device configuration of an ultrasonic diagnostic device 100 according to the present embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is a block diagram showing the functional configuration of the ultrasonic diagnostic device 100 according to the present embodiment. Fig. 2(a) is a diagram showing a schematic configuration of a stepping motor 210. Fig. 2(b) is a diagram showing the drive current of the stepping motor 210 for microsteps. Fig. 3(a) is a diagram showing the step operation of the stepping motor 210 in pulse units. Fig. 3(b) is a diagram showing the step operation of the stepping motor 210 in microstep units. Fig. 3(c) is a diagram showing the relationship between the pulse unit and the microstep unit of the stepping motor 210. Fig. 4 is a schematic cross-sectional perspective view of an ultrasonic probe main body 2a. Fig. 5 is a circuit diagram of a drive circuit unit 24.

As shown in FIG. 1, the ultrasound diagnostic device 100 of this embodiment includes an ultrasound diagnostic device main body 1 and an ultrasound probe 2. The ultrasound probe 2 is an ultrasound probe having a swing mechanism for obtaining a three-dimensional (3D) image as an ultrasound image. The ultrasound probe 2 is connected to the ultrasound diagnostic device main body 1 so as to enable transmission and reception of control signals and data with the ultrasound diagnostic device main body 1 and power supply from the ultrasound diagnostic device main body 1.

The ultrasound diagnostic device main body 1 includes a control unit 11, a transmission/reception unit 12, an image processing unit 13 as an image generating unit, a display control unit 14, a display unit 15, an operation input unit 16, a storage unit 17, and the like. The ultrasound probe 2 includes an ultrasound probe main body 2a, a cable 2b, and a connector 2c as a connector unit. The ultrasound probe main body 2a is the main body (header unit) of the ultrasound probe 2. The cable 2b is a signal line and a power supply cable that connects between the ultrasound probe main body 2a and the connector 2c. The connector 2c is a plug connector on the ultrasound probe 2 side, and is electrically connected to a receptacle connector (not shown) provided on the ultrasound diagnostic device main body 1. The ultrasound probe main body 2a includes a swing mechanism unit 21, a position detection unit 22, a transducer array 23 as a transducer unit, and the like. The connector 2c includes a drive circuit unit 24, a swing control unit 25, and the like.

The control unit 11 includes a CPU, RAM (Random Access Memory), and ROM, and controls the overall operation of the ultrasound diagnostic device 100. The CPU controls each part of the ultrasound diagnostic device 100. The RAM is a volatile memory that temporarily stores various information in a writable and readable manner. The ROM is a non-volatile memory in which various information and programs are stored in a readable manner. More specifically, the control unit 11 reads out a specified program from various programs stored in the ROM using the CPU, expands it into the RAM, and executes various processes in cooperation with the expanded program.

For example, the control unit 11 controls the transmission/reception unit 12 and the image processing unit 13, and outputs various control information for image generation such as the imaging position of the image data to be processed, to perform processing for generating ultrasound image data. The control unit 11 also acquires position information converted from the number of microsteps input from the swing control unit 25 (drive position processing unit 253 described later) as position information of the transducer array 23 in the swing mechanism unit 21 based on the swing control unit 25, and can use this position information for generating ultrasound image data.

Under the control of the control unit 11, the transmission/reception unit 12 scans each transducer (acoustic element) in the transducer array 23, generates a drive signal that sequentially causes a desired transducer to generate and emit (transmit) ultrasound, and outputs it to the transducer array 23, while acquiring an electrical signal related to the ultrasound (echo) that is reflected by a subject such as a patient and enters (receives) the transducer. The transmission/reception unit 12 performs various processes, such as adjusting and delaying the timing of transmitting and receiving ultrasound for each transducer. The transmission/reception unit 12 also amplifies the received signal and digitally converts it at a predetermined sampling frequency, and performs processes such as delaying the desired timing for each transducer, phasing and adding, and generating sound ray data.

The image processing unit 13 performs processing to generate diagnostic ultrasound image data based on the sound ray data acquired from the transmission/reception unit 12 under the control of the control unit 11. The ultrasound image data generated by the image processing unit 13 includes live B (Brightness) mode image data and a series of video data thereof that are displayed on the display unit 15 in almost real time, and in particular includes ultrasound image data (three-dimensional B-mode image data) relating to a three-dimensional structure acquired using an ultrasound probe 2 for generating three-dimensional B-mode images. The position data of the transducer array 23 of the ultrasound probe 2 acquired from the control unit 11 is used to generate the three-dimensional B-mode image data.

Based on the control of the control unit 11, the display control unit 14 performs coordinate conversion of the ultrasound image data output from the image processing unit 13 to generate an image signal, and displays an ultrasound image on the display unit 15 based on the image signal.

The display unit 15 includes a display screen using any of various display methods such as an LCD (Liquid Crystal Display), an organic EL (Electro-Luminescent) display, an inorganic EL display, a plasma display, and a CRT (Cathode Ray Tube) display, and a drive unit for the display screen. The display unit 15 generates a drive signal for the display screen (each display pixel) according to the display information output from the control unit 11 and the image signal of the ultrasound image data generated by the display control unit 14, and displays a menu related to ultrasound diagnosis, status, and measurement data based on the received ultrasound on the display screen. In addition, one or more lamps (such as LED (Light Emitting Diode) lamps) may be provided to indicate whether the power is on or off depending on the lighting state.

The operation input unit 16 is an operation device such as a push button switch, a keyboard, a mouse, or a trackball, or a combination of these, and accepts operation input from a user of the ultrasound diagnostic device 100, such as a doctor or a medical technician. It accepts operation input from the user and outputs an operation signal corresponding to the operation input to the control unit 11. Alternatively, in addition to or instead of the above-mentioned configuration, the operation input unit 16 may be provided with a touch sensor (touch panel) provided on the display screen of the display unit 15, detect a touch operation on the display screen of the display unit 15, and output an operation signal related to the type of operation and the position.

The operation input unit 16 and the display unit 15 may be provided integrally with the housing of the ultrasound diagnostic device main body 1, or may be attached externally via an RGB cable, a USB (Universal Serial Bus) cable, an HDMI (High-Definition Multimedia Interface) (registered trademark) cable, or the like. In addition, the ultrasound diagnostic device main body 1 may be provided with only an operation input terminal and a display output terminal, and conventional peripheral devices for operation and display may be connected to these terminals for use.

The storage unit 17 is composed of a hard disk drive (HDD), a solid state drive (SSD), etc., and stores various information such as ultrasound image data in a readable and writable manner. In particular, the storage unit 17 stores oscillation information. The oscillation information includes information related to oscillation, such as the oscillation range (oscillation start position, oscillation end position) of the transducer array 23, the target oscillation speed V1, and the oscillation period C1.

The oscillation mechanism 21 includes a stepping motor 210 shown in FIG. 2A and a mechanism for converting the rotation of the stepping motor 210 into oscillation, and is step-driven via the drive circuit 24 by a drive signal from the oscillation control unit 25 to oscillate the transducer array 23. The stepping motor 210 is capable of micro-step driving in addition to pulse driving (for example, in units of 7.2 degrees) as a step drive. The micro-step drive rotates (steps) the rotor in a CW (ClockWise) direction (forward direction) or CCW (CounterClockWise) direction (reverse direction) (direction of change in angular position) in micro-steps of 0.045 degrees, for example, in which the pulse is further divided by 160, to an angular position corresponding to the phase (current phase) of the excitation current flowing through the coil of the stepping motor 210 provided at angular intervals corresponding to the micro-step (pulse). However, in this embodiment, the stepping motor 210 is only driven using the microstep method (microstep drive).

Figure 2(a) shows an example of the structure of the stepping motor 210 of the oscillating mechanism 21. The stepping motor 210 has a rotor 211 and two coils (stators) 212A and 212B. The coils 212A and 212B are arranged so that their electrical angles are offset from each other by 90 degrees. Therefore, the directions of the magnetic fields of the coils 212A and 212B relative to the rotor 211 are also offset from each other by 90 degrees electrical angle with respect to the central angle of the rotor 211. In Figure 2(a), the coil 212A is shown as the A-phase side, and the coil 212B is shown as the B-phase side.

The rotor 211 has a magnet, such as a permanent magnet, and is configured to be rotatable so as to be stable at a position corresponding to the magnetic field from the coils 212A and 212B. As shown in FIG. 2(b), a constant current value is decomposed into a drive current (A-phase drive current; solid line on the figure) to the coil 212A and a drive current (B-phase drive current; dashed line on the figure) to the coils 212A and 212B as alternating currents with a phase difference of 90 degrees from each other, and the rotor 211 rotates according to the current phase. In addition, by stopping the change in the current phase at the timing of a specific current phase, the rotor 211 can be stopped at a position corresponding to the current phase at that time. With this configuration, as shown in FIG. 3(a), by inputting one pulse of the A-phase drive current and the B-phase drive current to the coils 212A and 212B as the stators, the coils 212A and 212B and the rotor 211 pull each other, and the rotor 211 is stepped in one pulse unit.

Figure 3(c) shows the pulses of the stepping motor 210, the microsteps of the stepping motor 210, and the waveform of the drive signal during microsteps (drive waveform). The arrows showing the steps in pulse units of the stepping motor 210 in Figure 3(c) cause the stepping motor 210 to move in pulse units as shown in Figure 3(a). The arrows showing the microsteps of the stepping motor 210 in Figure 3(c) cause the stepping motor 210 to move in microstep units as shown in Figure 3(b).

In this way, by inputting an A-phase drive current and a B-phase drive current of an arbitrary number of microsteps obtained by dividing the pulses of the stepping motor 210 into the coils 212A and 212B, the rotor 211 is stepped in units of the corresponding number of microsteps, as shown in FIG. 3(b). Therefore, the rotation of the stepping motor 210 can be controlled in units of microsteps, which have a higher resolution than pulse units.

As shown in Figure 3(a), the position where rotor 211 and coils 212A and 212B face each other is very stable because they magnetically attract each other head-on, and is called a stable point. In contrast, if rotor 211 and coils 212A and 212B are stopped at a position where they do not face each other using microstep driving, as shown in Figure 3(b), there is no problem if there is sufficient driving torque, but since they are pulled to the stable points on both sides, this position is called an unstable point.

When the stepping motor 210 is driven in microsteps, it has an effect at the start of oscillation when the drive torque changes. If it is stopped at an unstable point and that position is close to a stable point, it will be pulled to the stable point the moment the drive torque changes at the start of oscillation, or if it is stopped at a stable point and starts to oscillate, it will not be able to leave the stable point and it will take a long time to start moving.

Returning to FIG. 1, the position detection unit 22 has a rotary encoder that can determine the relative rotation angle, and a limiter that can determine the absolute fixed position. The rotary encoder converts the mechanical change in rotation into an electrical signal, and outputs this signal as an encoder value. Methods for capturing mechanical changes in the rotary encoder include optical and magnetic methods. The position detection unit 22 obtains the fixed position from the limiter, and based on the fixed position, counts the encoder value obtained from the rotary encoder and converts it into the rotation angle of the transducer array 23, thereby obtaining the current position of the transducer array 23. In this embodiment, an inexpensive magnetic type is used for the rotary encoder of the position detection unit 22, and the position information cannot be used as position information for generating an ultrasound image.

For example, if a stepping motor 210 with a pulse step of 7.2 degrees is used, then for one rotation (360 degrees) of the stepping motor 210, the encoder value will be 40 x 360/7.2 = 2000 counts (in 0.18 degree units), and the number of microsteps will be 160 x 360/7.2 = 8000 counts (in 0.045 degree units). Therefore, the resolution is pulses < encoder value < microsteps, but the accuracy is encoder value < microsteps < pulses if an inexpensive magnetic type is used for the rotary encoder.

The transducer array 23 is a one-dimensional array of multiple transducers (acoustic elements) fixed in a predetermined array direction (scanning direction, azimuth direction), and transmits ultrasound (transmitted ultrasound) into a subject such as a living body (not shown), and receives reflected waves of ultrasound reflected within the subject (reflected ultrasound: echo). The transducer array 23 performs a rotational movement related to the oscillation within a predetermined angle range in a direction perpendicular to the array direction in response to the rotational movement of the oscillation mechanism unit 21, and changes the oscillation position (direction) related to the emission and incidence of ultrasound. The transducer has a piezoelectric element and electrode wiring provided on both ends of the deformation direction of the piezoelectric element. When a voltage corresponding to a drive signal from the transmission/reception unit 12 is applied between the electrodes, the piezoelectric element deforms to generate ultrasound and emit it in the set direction, and also deforms in response to the incidence of ultrasound from the direction, outputting an electrical signal corresponding to the intensity of the incidence to the electrode wiring.

Now, referring to FIG. 4, the configuration of the ultrasonic probe body 2a having the transducer array 23 will be described. The ultrasonic probe body 2a has a transducer array section 230, a support rotation section 203, oil 205, etc., in a housing 202 including a window 201. The window 201 is made of a material that transmits ultrasonic waves. The transducer array section 230 has a transducer array 23, electrodes, a backing material, etc. The transducer array 23 (transducer array section 230) transmits signals between the transmitter/receiver section 12 through a flexible cable 231, cable 2b, and connector 2c. The support rotation section 203 supports the transducer array section 230 and rotates around a rotation axis 204. By rotating the rotation axis 204 within the display plane, each transducer of the transducer array 23 swings from the swing position in the figure, that is, the directivity direction of the transducer array 23 swings from the upward direction to the left and right.

The transducer array 23 is housed as part of the transducer array unit 230 in a housing 202 including a window 201, and the housing 202 is filled with oil 205. The rotating shaft 204 is rotated via the stepping motor 210 of the oscillation mechanism unit 21 in response to the control of the drive circuit unit 24 by the oscillation control unit 25.

As shown in FIG. 5, the drive circuit section 24 has an A-phase drive circuit 240A and a B-phase drive circuit 240B. The A-phase drive circuit 240A has a current detection section 241A, a differential amplifier 242A, power amplifiers 243A and 244A, a + power supply 245A, a - power supply 246A, and an inversion circuit 247A. The B-phase drive circuit 240B has a configuration similar to that of the A-phase drive circuit 240A, so illustration and description are omitted.

When the control unit 11 instructs the swing control unit 25 to swing the transducer array 23, the swing control unit 25 generates A-phase phase data (sine wave data) for the A-phase drive circuit 240A and B-phase phase data (sine wave data) having a phase difference of 90 degrees from the A-phase phase data based on the rotation angle (electrical angle) of the stepping motor 210 corresponding to the swing instruction. The swing control unit 25 generates an A-phase current command value and a B-phase current command value based on the generated A-phase phase data and B-phase phase data. The swing control unit 25 outputs the generated A-phase current command value to the A-phase drive circuit 240A and the B-phase current command value to the B-phase drive circuit 240B. The operation of the A-phase drive circuit 240A to which the A-phase current command value has been input is described below.

The differential amplifier 242A detects the difference between the A-phase current command value input from the oscillation control unit 25 and the amplified value of the current flowing through the coil 212A on the A-phase side of the stepping motor 210 detected by the current detection unit 241A.

The power amplifiers 243A and 244A are analog amplifiers that amplify the input current. The differential amplifier 242A and the power amplifier 243A form a linear amplifier (e.g., a class AB amplifier). The output terminal of the power amplifier 243A is connected to the input terminals of the power amplifiers 243A and 244A via, for example, an operational amplifier inversion circuit 247A. The inversion circuit 247A and the power amplifier 244A form a linear amplifier (e.g., a class AB amplifier). The + power supply 245A supplies a positive power supply voltage to the power amplifiers 243A and 244A. The - power supply 246A supplies a negative power supply voltage to the power amplifiers 243A and 244A.

The output terminal of the power amplifier 243A is connected to the positive terminal of the coil 212A. The output terminal of the power amplifier 244A is connected to the negative terminal of the coil 212A. By operating so that the output voltage of the differential amplifier 242A becomes zero, the current output to the coil 212A becomes constant. Similarly, the B-phase drive circuit 240B outputs a current to the coil 212B.

In this embodiment, the A-phase current command value of the A-phase current to be passed through coil 212A is set in advance. In this embodiment, speed feedback control is not performed, in which the A-phase current command value is changed by reading the temporal change in the current value from the position detection unit 22 (rotary encoder). The A-phase current command value is set to a level that does not cause step-out in order to minimize heat generation. The B-phase current command value of the B-phase current to be passed through coil 212B is the same as the A-phase current command value.

The oscillation control unit 25 is an electronic circuit such as a CPU, RAM, and ROM, and controls the drive circuit unit 24. This electronic circuit may be an MPU (Micro Processing Unit). The oscillation control unit 25 reads out a specified program from various programs stored in the ROM by the CPU, expands it in the RAM, and executes various processes in cooperation with the expanded program. In particular, the ROM of the oscillation control unit 25 stores a transducer array oscillation program for executing the transducer array oscillation process described below.

The swing control unit 25 has a swing drive control unit 251, a control switching unit 252, and a drive position processing unit 253. The swing drive control unit 251 outputs a drive signal for moving the transducer array 23 to a desired swing position to the drive circuit unit 24 at an appropriate timing based on data related to the operation of the swing mechanism unit 21. The control switching unit 252 detects whether the position information of the transducer array 23 detected by the position detection unit 22 has changed.

The drive position processing unit 253 converts the number of microsteps provided by the control unit 11 into position information for the transducer array 23, and outputs the position information for the transducer array 23 to the control unit 11. The number of microsteps may be converted into angles in advance and used as position information as is, but in reality an error occurs that depends on the structure of the oscillation mechanism unit 21. There are two main factors. One is that there is no effect at low speeds, but at high speeds, a delay occurs in the actual position compared to the input number of microsteps due to the moment of the structure. The other is that an offset occurs between the current position converted from the number of microsteps and the true current position due to the effect of backlash in the CW and CCW directions as the rotation directions of the transducer array 23. These effects are known from measurements in advance, so corrections are made in the drive position processing unit 253.

For each part of the ultrasound diagnostic device 100, some or all of the functions of each functional block can be realized as a hardware circuit such as an integrated circuit. An integrated circuit is, for example, an LSI (Large Scale Integration), and an LSI may be called an IC (Integrated Circuit), a system LSI, a super LSI, or an ultra LSI depending on the degree of integration. In addition, the method of integration is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor, or may use an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI. In addition, some or all of the functions of each functional block may be executed by software. In this case, the software is stored in one or more storage media such as a ROM, an optical disk, or a hard disk, and the software is executed by a processor.

Next, the operation of the ultrasound diagnostic device 100 will be described with reference to Figures 6 to 8. Figure 6 is a flowchart showing the transducer array oscillation process. Figure 7 is a diagram showing the encoder value, microstep output, and actual oscillation speed of the position detection unit 22 when the period is set to twice the target oscillation speed V1 at the start of oscillation. Figure 8 is a diagram showing the encoder value, microstep output, and actual oscillation speed of the position detection unit 22 when the oscillation speed is set to the maximum self-start frequency at the start of oscillation.

The transducer array oscillation process executed by the ultrasound diagnostic device 100 will be described with reference to FIG. 6. The transducer array oscillation process is a process of oscillating the transducer array 23 of the ultrasound probe 2 in a three-dimensional ultrasound image display process for generating and displaying three-dimensional B-mode image data. As a three-dimensional ultrasound image display process, the control unit 11 controls the oscillation control unit 25 to oscillate the transducer array 23, while controlling the transmission/reception unit 12 and the image processing unit 13 to output various control information for image generation such as the imaging position of the image data to be processed to generate three-dimensional ultrasound image data (three-dimensional B-mode image data), and controls the display control unit 14 to display the generated three-dimensional ultrasound image data on the display unit 15.

In the ultrasound diagnostic device 100, for example, a three-dimensional ultrasound image display process is executed, and an instruction to execute a transducer array oscillation process is input from the control unit 11, which triggers the oscillation control unit 25 to execute the transducer array oscillation process according to the transducer array oscillation program stored in the ROM of the oscillation control unit 25.

The control unit 11 accepts a setting input of oscillation information related to the oscillation of the transducer array 23 in the 3D ultrasound image display processing from a user such as a doctor or technician via the operation input unit 16, and stores the set oscillation information (oscillation start position, oscillation end position, target oscillation speed V1, oscillation period C1) in the storage unit 17. Here, the oscillation start position of the oscillation information is set to the end position on one end side of the oscillation range of the transducer array 23 (e.g., the left end in FIG. 4), and the oscillation end position of the oscillation information is set to the end position on the other end side of the oscillation range of the transducer array 23 (e.g., the right end in FIG. 4).

As shown in FIG. 6, first, the oscillation control unit 25 reads the oscillation information from the memory unit 17 via the control unit 11, and calculates the period of the microsteps to be output to the drive circuit unit 24 from the target oscillation speed V1 (step S10).

Then, the oscillation control unit 25 determines whether the target oscillation speed V1 read out in step S10 is equal to or lower than a predetermined speed V0, which is a threshold value for determining whether the oscillation speed is low (step S11). The predetermined speed V0 is, for example, an oscillation speed sufficiently slower than the oscillation speed corresponding to the maximum self-start frequency (half or less of the oscillation speed corresponding to the maximum self-start frequency), and is assumed to be 1 rpm here. In this embodiment, as described below, a process is performed to lower the period of the microstep output during oscillation at low speeds of the target oscillation speed V1.

If the target rocking speed V1 is a low speed equal to or lower than the predetermined speed V0 (step S11; YES), the rocking control unit 25 drives the stepping motor 210 of the rocking mechanism unit 21 in microsteps using the rocking drive control unit 251, and moves the transducer array 23 to the rocking start position of the rocking information read out in step S10 using the position information of the transducer array 23 detected by the position detection unit 22 (step S12).

Then, the swing control unit 25 sets the swing direction of the transducer array 23 (step S13). When step S13 is executed for the first time, the swing direction is set to the CCW direction from the swing start position of step S12, and when step S13 is executed thereafter, the swing direction is set to the opposite swing direction to the previous swing direction. Then, the swing control unit 25 sets the period of the microstep output for microstep driving the stepping motor 210 of the swing mechanism unit 21 in the swing direction set in step S13 by the swing drive control unit 251 to a period corresponding to twice the target swing speed V1 (step S14).

How much smaller the period should be set than the period of the target rocking speed V1 depends on the inertia of the rocking mechanism and the detent torque (magnetic attraction force in a non-excited state acting between the rotor and stator) of the stepping motor 210 used. If a stepping motor 210 with a large detent torque is used, the period should be set smaller. Setting the period too small will cause step-out and overshoot, so the ultrasonic image should be viewed and the period set to a level that does not have an effect. In this embodiment, for example, a period corresponding to twice the target rocking speed V1 is appropriate as the period to be set. Since twice the period can be handled by bit shifting, it is faster than multiplication and has a lighter calculation load, which is convenient for the rocking control unit 25.

Then, the oscillation control unit 25 starts acquiring the encoder value corresponding to the current position of the transducer array 23 from the position detection unit 22 (step S15). Then, the oscillation control unit 25 controls the drive circuit unit 24 by the oscillation drive control unit 251 to output microsteps with a period corresponding to twice the target oscillation speed V1 set in step S14 in the oscillation direction set in step S13, and starts oscillating the transducer array 23 toward the oscillation end position (target position) (step S16).

Then, the swing control unit 25 monitors and determines whether the current encoder value being acquired from the position detection unit 22 has changed since the start of the swing using the control switching unit 252 (step S17). If the current encoder value has not changed (step S17; NO), the process proceeds to step S17. If the current encoder value has not changed (step S17; YES), the swing control unit 25 sets the period of the microstep output to a period corresponding to the target swing speed V1 calculated in step S10, and continues swing control by the swing drive control unit 251 according to the set period of the microstep output (step S18).

Then, the oscillation control unit 25 controls the oscillation drive control unit 251 to stop the transducer array 23 at the output of the number of microsteps for the target oscillation range (the oscillation range from the oscillation start position to the oscillation end position read out in step S10) (step S19). In this oscillation, the encoder value of the position detection unit 22 is not used, and the drive position processing unit 253 outputs the position information of the transducer array 23 converted according to the output of the microsteps to the control unit 11.

Then, the oscillation control unit 25 determines whether the oscillation period C1 read out in step S10 has elapsed since the start of oscillation in step S16 (step S20). If the oscillation period C1 has not elapsed (step S20; NO), the process proceeds to step S20. If the oscillation period C1 has elapsed (step S20; YES), the process proceeds to step S13. If the process proceeds to step S13, the oscillation direction is set in the opposite direction to the previous oscillation direction in the subsequent steps S13 to S20, and the oscillator array 23 is oscillated in the same manner. In this oscillation in the opposite direction, the oscillation start position is the oscillation end position used in the previous oscillation, and the oscillation end position is the oscillation start position used in the previous oscillation. These oscillations are repeated.

If the target rocking speed V1 is greater than the predetermined speed V0 (step S11; NO), the rocking control unit 25 controls the drive circuit unit 24 by the rocking drive control unit 251 to perform normal rocking processing (step S21). The normal rocking processing is, for example, a process in which the rocking drive control unit 251 moves the transducer array 23 to the rocking start position, sets a period corresponding to the target rocking speed V1 in one rocking direction from the rocking start position to the rocking end position using the rocking information read out in step S10, drives the drive circuit unit 24 by the number of microsteps for the target rocking range, and similarly sets a period corresponding to the target rocking speed V1 in the opposite rocking direction to drive by microsteps, and repeats these processes.

7 and 8, a specific example of the operation of the transducer array oscillation process will be described. As shown in FIG. 7, the oscillation control unit 25 of the ultrasound diagnostic device 100 executes the transducer array oscillation process, and in step S16, the oscillation of the transducer array 23 is started at time t1. Since the period of the microstep output is set to a period corresponding to twice the target oscillation speed V1 in step S14, the transducer array 23 is accelerated by the oscillation control of the period, and the actual oscillation speed of the transducer array 23 increases. Then, in step S17, the encoder value of the position detection unit 22 changes from 0 to a positive value at time t2. Then, in step S18, the period of the microstep output is set to a period corresponding to the target oscillation speed V1, and after time t2, the oscillation speed of the actual transducer array 23 becomes approximately the target oscillation speed V1, and the transducer array 23 is oscillated. After time t2, the encoder value is not used to control the oscillation until the oscillation direction is reversed (step S20; YES).

8, the oscillation control unit 25 of the ultrasound diagnostic device 100 executes the oscillator array oscillation process, and in step S14, the period of the microstep output is set to a period corresponding to a speed (here, for example, an oscillation speed corresponding to the maximum self-starting frequency) that is excessively larger than twice the target oscillation speed V1. In step S16, the oscillation of the oscillator array 23 is started at time t1, the oscillator array 23 is accelerated, and the actual oscillation speed of the oscillator array 23 increases. However, the period of the microstep output is too small, so the oscillation speed becomes too fast, and in step S17, the encoder value of the position detection unit 22 changes from 0 to a positive value at time t2, and in step S18, the period of the microstep output is set to a period corresponding to the target oscillation speed V1, but due to the inertia caused by the oscillation speed immediately before, an overshoot occurs in which the oscillation speed of the actual oscillator array 23 temporarily greatly exceeds the target oscillation speed V1 around time t2. Furthermore, if the period of the microstep output is set to a period corresponding to an oscillation speed equal to or greater than the maximum self-start frequency, stepping out may occur in the worst case. More precisely, as the frequency of the microstep output is increased from a low value and approaches the maximum self-start frequency, an overshoot begins to occur. The purpose of the oscillation from time t1 to time t2 is to escape the influence of the stable point, and since this overshoot adversely affects the ultrasonic image, the period of the microstep output before the change in the encoder value is detected cannot be made too small. For this reason, in step S14, the period of the microstep output is set to a period greater than the period corresponding to the maximum self-start frequency (the oscillation speed corresponding to it) and corresponding to twice the target oscillation speed V1.

As described above, according to this embodiment, the ultrasound probe 2 includes a transducer array 23 that transmits and receives ultrasound, a swing mechanism 21 that swings the transducer array 23 with microstep drive, a drive circuit 24 that drives the swing mechanism 21, and a swing control unit 25 that sets the microstep frequency of the swing mechanism 21 to a period smaller than the period corresponding to the target swing speed from the start of swing of the transducer array 23 until a predetermined timing, and sets the microstep period to the period corresponding to the target swing speed after the predetermined timing to control the drive circuit 24. The ultrasound diagnostic device 100 includes the ultrasound probe 2 and an image processing unit 13 that generates ultrasound image data based on the reception signal obtained by the ultrasound probe 2.

As a result, the drive current of the oscillation mechanism 21 is not increased, and the transducer array 23 is not feedback-controlled, so heat generation in the oscillation mechanism 21 and the drive circuit 24 can be suppressed, while oscillation can be started appropriately to accurately position the transducer array 23, avoiding the phenomenon in which both ends of the ultrasound image (ends near the oscillation start position) become stretched, shortening the oscillation start time, and improving the real-time nature of ultrasound images such as three-dimensional images.

The ultrasonic probe 2 also includes a position detector 22 that detects position information of the transducer array 23. The predetermined timing is the timing at which the position information of the transducer array 23 detected by the position detector 22 changes from the start of the oscillation. Therefore, by using the position detector 22 to detect the start of rotation of the stepping motor 210 of the oscillation mechanism 21 at the start of the oscillation, the transducer array 23 can be appropriately rotated to the target oscillation speed V1 from the start of the oscillation, and the oscillation can be switched to normal microstep drive oscillation at an appropriate timing. Furthermore, since the transducer array 23 is not feedback controlled, the amplitude of the drive current is not changed. Therefore, the oscillation can be appropriately started without being affected by heat generation.

The position detection unit 22 is a magnetic (rotary) encoder. Therefore, an inexpensive encoder is used for the position detection unit 22, so the ultrasound probe 2 and ultrasound diagnostic device 100 can be made inexpensive. Even if a magnetic encoder with low accuracy is used, the position detection unit 22 is used only to detect changes in position information, so the transducer array 23 can start to oscillate appropriately.

The oscillation control unit 25 also determines whether the target oscillation speed V1 is equal to or lower than a predetermined speed V0, and if it is equal to or lower than the predetermined speed V0, sets the microstep frequency to a period smaller than the period corresponding to the target oscillation speed V1 from the start of oscillation of the transducer array until a predetermined timing (the timing of the change in the position information of the position detection unit 22), and after the predetermined timing, sets the microstep period to a period corresponding to the target oscillation speed V1 to control the drive circuit unit 24. Therefore, when the target oscillation speed V1 is a low speed equal to or lower than the predetermined speed V0, the position of the transducer array 23 can start to oscillate appropriately while suppressing heat generation, and when the target oscillation speed V1 is a high speed greater than the predetermined speed V0, it can switch to normal microstep drive oscillation.

Furthermore, a period smaller than the period corresponding to the target rocking speed V1 is a period larger than the period corresponding to the maximum self-start frequency. Furthermore, a period smaller than the period corresponding to the target rocking speed V1 is a period corresponding to twice the target rocking speed V1. Since the amplitude of the drive waveform is not increased and only the period is changed, the position of the transducer array 23 can be appropriately started to rock while suppressing heat generation, and the occurrence of overshoot, in which the actual rocking speed of the transducer array 23 temporarily greatly exceeds the target rocking speed V1, can be reduced.

The ultrasound probe 2 also includes a connector 2c for connecting to the ultrasound diagnostic device main body 1. The connector 2c includes a drive circuit unit 24 and a swing control unit 25. As a result, the ultrasound probe main body 2a does not include the drive circuit unit 24 and the swing control unit 25, so the size of the ultrasound probe main body 2a can be reduced, and heat generation from the ultrasound probe main body 2a can be reduced to prevent the user holding the probe or the subject being placed against the probe from feeling hot or being burned during an examination. Furthermore, heat generation from the drive circuit unit 24 and the swing control unit 25 can also be reduced, and heat generation from the connector 2c can be reduced, so that the user holding the probe at the time of connection can be prevented from feeling hot or being burned. The drive circuit unit 24 and the swing control unit 25 may be configured to be stored in the ultrasound probe main body 2a.

(Modification)
A modification of the above embodiment will be described with reference to Fig. 9. Fig. 9 is a block diagram showing the functional configuration of an ultrasound diagnostic device 100D according to this modification.

In the above embodiment, the drive circuit unit 24 and the swing control unit 25 are provided in the connector 2c of the ultrasound probe 2. In this modified example, the drive circuit unit and the swing control unit are provided in the ultrasound diagnostic device body. In the device configuration of this modified example, parts that are the same as those in the ultrasound diagnostic device 100 of the above embodiment are given the same reference numerals and their description is omitted.

As shown in FIG. 9, the ultrasound diagnostic device 100D of this modified example includes an ultrasound diagnostic device main body 1D and an ultrasound probe 2D. The ultrasound diagnostic device main body 1D includes a control unit 11D, a transmission/reception unit 12, an image processing unit 13, a display control unit 14, a display unit 15, an operation input unit 16, a storage unit 17, a drive circuit unit 18, and the like. The control unit 11D is similar to the control unit 11 of the above embodiment, but also has the same functions as the rocking control unit 25 of the above embodiment, and also functions as the rocking drive control unit 111, the control switching unit 112, and the drive position processing unit 113, which are similar to the rocking drive control unit 251, the control switching unit 252, and the drive position processing unit 253, respectively. The drive circuit unit 18 is similar to the drive circuit unit 24 of the above embodiment.

The ultrasonic probe 2D includes an ultrasonic probe body 2a, a cable 2b, and a connector 2d. The connector 2d has a configuration similar to that of the connector 2c of the first embodiment, except that the drive circuit unit 24 and the swing control unit 25 are removed.

As described above, according to this modification, the ultrasound diagnostic device 100D includes an ultrasound probe 2D including a transducer array 23 for transmitting and receiving ultrasound and a swing mechanism unit 21 for swinging the transducer array 23 by microstep drive, a drive circuit unit 18 for driving the swing mechanism unit 21, an image processing unit 13 for generating ultrasound image data based on a reception signal obtained by the ultrasound probe 2D, and a control unit 11D for setting the frequency of the microstep of the swing mechanism unit 21 to a period smaller than the period corresponding to the target swing speed V1 from the start of swing of the transducer array 23 until a predetermined timing, and setting the period of the microstep to the period corresponding to the target swing speed V1 after the predetermined timing to control the drive circuit unit 18. Therefore, the same effect as that of the ultrasound diagnostic device 100 of the above embodiment is achieved, and since the ultrasound probe 2D does not have the drive circuit unit 18 and the control unit 11D, heat generation of the ultrasound probe 2D can be further reduced.

In the above explanation, an example has been disclosed in which a ROM is used as a computer-readable medium for the program according to the present invention, but this is not limiting. As other computer-readable media, non-volatile memory such as a flash memory, and portable recording media such as a CD-ROM can be applied. In addition, a carrier wave can also be applied to the present invention as a medium for providing data for the program according to the present invention via a communication line.

The above-described embodiments and modifications are merely examples of suitable ultrasound probes, ultrasound diagnostic devices, and programs according to the present invention, and are not intended to be limiting.

Furthermore, the detailed configurations and detailed operations of the components constituting the ultrasound diagnostic devices 100 and 100D in the above embodiments and modifications may be modified as appropriate without departing from the spirit and scope of the present invention.

100, 100D Ultrasonic diagnostic device 1, 1D Ultrasonic diagnostic device main body 11, 11D Control unit 111 Oscillation drive control unit 112 Control switching unit 113 Drive position processing unit 12 Transmitting/receiving unit 13 Image processing unit 14 Display control unit 15 Display unit 16 Operation input unit 17 Memory unit 18 Drive circuit unit 2, 2D Ultrasonic probe 201 Window 202 Housing 203 Support rotation unit 204 Rotation shaft 205 Oil 21 Oscillation mechanism unit 210 Stepping motor 211 Rotor 212A, 212B Coil 22 Position detection unit 23 Transducer array 230 Transducer array unit 231 Flexible cable 2b Cable 2c, 2d Connector 24 Drive circuit unit 240A A-phase drive circuit 241A Current detection unit 242A Differential amplifier 243A, 244A Power amplifier 245A + power supply 246A - power supply 247A Inversion circuit 240B B-phase drive circuit 25 Swing control section 251 Swing drive control section 252 Control switching section 253 Drive position processing section

Claims (13)

A transducer unit for transmitting and receiving ultrasonic waves;
an oscillation mechanism for oscillating the oscillator unit by microstep drive;
A drive circuit unit that drives the swing mechanism unit;
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit ,
An ultrasonic probe , wherein the period smaller than the period corresponding to the target oscillation speed is larger than the period corresponding to the maximum self-starting frequency . a position detection unit that detects position information of the transducer unit,
2. The ultrasonic probe according to claim 1, wherein the predetermined timing is a timing at which the detected position information of the transducer portion changes from the start of the oscillation. The ultrasonic probe according to claim 2, wherein the position detection unit is a magnetic encoder. An ultrasonic probe according to any one of claims 1 to 3, wherein the oscillation control unit determines whether the target oscillation speed is equal to or lower than a predetermined speed, and if it is equal to or lower than the predetermined speed, sets the frequency of the microsteps to a period smaller than the period corresponding to the target oscillation speed from the start of oscillation of the transducer unit until the predetermined timing, and sets the period of the microsteps to the period corresponding to the target oscillation speed after the predetermined timing to control the drive circuit unit. 5. The ultrasonic probe according to claim 1, wherein the period smaller than the period corresponding to the target oscillation speed is a period corresponding to twice the target oscillation speed. A connector for connecting to the ultrasound diagnostic device body is provided.
The ultrasonic probe according to claim 1 , wherein the connector portion includes the drive circuit portion and the swing control portion. An ultrasonic probe according to any one of claims 1 to 6 ;
an ultrasonic diagnostic device main body having an image generating unit that generates ultrasonic image data based on a reception signal obtained by the ultrasonic probe. A transducer unit for transmitting and receiving ultrasonic waves;
an ultrasonic probe including a swing mechanism that swings the transducer unit by microstep drive;
A drive circuit unit that drives the swing mechanism unit;
an image generating unit that generates ultrasound image data based on a reception signal obtained by the ultrasound probe;
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit ,
An ultrasonic diagnostic apparatus , wherein the period smaller than the period corresponding to the target rocking speed is larger than the period corresponding to the maximum self-starting frequency . The ultrasonic probe includes:
a position detection unit that detects position information of the transducer unit,
The ultrasonic diagnostic apparatus according to claim 8 , wherein the predetermined timing is a timing at which the detected position information of the transducer portion changes from the start of the oscillation. The ultrasonic diagnostic apparatus according to claim 9 , wherein the position detector is a magnetic encoder. 11. The ultrasonic diagnostic apparatus according to claim 8, wherein the rocking control unit determines whether the target rocking speed is equal to or lower than a predetermined speed, and if equal to or lower than the predetermined speed, sets a frequency of the microsteps to a period smaller than a period corresponding to the target rocking speed from the start of rocking of the transducer unit until the predetermined timing , and sets the period of the microsteps to a period corresponding to the target rocking speed after the predetermined timing to control the drive circuit unit. 12. The ultrasonic diagnostic apparatus according to claim 8, wherein the period smaller than the period corresponding to the target rocking speed is a period corresponding to twice the target rocking speed. A transducer unit for transmitting and receiving ultrasonic waves;
an oscillation mechanism for oscillating the oscillator unit by microstep drive;
A drive circuit unit that drives the rocking mechanism unit.
a swing control unit that sets a period of a microstep frequency of the swing mechanism unit to a period smaller than a period corresponding to a target swing speed from the start of swing of the vibrator unit until a predetermined timing, and sets the period of the microstep to a period corresponding to the target swing speed after the predetermined timing to control the drive circuit unit;
Function as a
A program in which the period smaller than the period corresponding to the target rocking speed is larger than the period corresponding to the maximum self-starting frequency .

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