Ultrasonic volume probe circuit and four-dimensional scanning method thereof

Abstract

The present invention discloses an ultrasonic volume probe circuit and a four-dimensional scanning method thereof. An adaptive power circuit is implemented through zero-crossing detection and a holding capacitor (phase-sensitive negative feedback loop). The amplitude of an electrical signal is adjusted according to the load size, thereby adjusting the drive power level. The frequency of an input sine wave is further controlled to implement acceleration control, deceleration control, and uniform speed control of a two-phase stepper motor. This enables the ultrasonic volume probe to operate continuously, avoiding vibration and other abnormal conditions caused by the sudden start-up of the two-phase stepper motor during operation. At the same time, four-dimensional scanning is performed while the two-phase stepper motor is under uniform speed control, enabling simultaneous image scanning while the two-phase stepper motor rotates, ensuring image continuity, and improving the scanning frame rate.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic imaging equipment, in particular to an ultrasonic volume probe circuit and a four-dimensional scanning method thereof. Background Art

[0002] Four-dimensional ultrasound imaging technology can record the body information of the object being tested and is often used in obstetrics and gynecology fetal malformation screening and other related examinations. The high scanning frame rate can better reflect the real-time changes in the morphology of the object being tested.

[0003] Ultrasonic volume probes primarily consist of an ultrasonic transducer, a stepper motor, and a mechanical transmission device. The transducer is driven to scan in different directions to acquire 3D / 4D volume data by controlling the rotation of the stepper motor. Traditionally, dedicated ICs have been used to drive stepper motor hardware. Currently, dedicated IC driver chips can achieve 128 or even higher subdivisions, fully ensuring smooth motor operation. However, most dedicated ICs use a chopping-type drive method to rotate the stepper motor. This drive method presents significant design challenges for designers in the field of ultrasonic imaging technology. This is because chopping-type drive of the stepper motor significantly interferes with the transducer's ultrasonic signal, hindering the acquisition of key information acquired through ultrasound.

[0004] For example, the method proposed in the Chinese patent application with patent publication number CN106691507A sets the position of the acoustic head, causes the motor to rotate to a specified position and scans a frame of two-dimensional image. After the scan is completed, the motor is driven to rotate to the next set position and scans another frame of two-dimensional image. However, the motor rotation and scanning cannot be performed at the same time. During the time the motor is rotating, the two-dimensional image cannot be scanned, and some key signals are likely to be lost. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide an ultrasound volume probe circuit that can drive a two-phase stepper motor to rotate and perform image scanning simultaneously, and to provide a four-dimensional scanning method for an ultrasound volume probe that can achieve a high scanning frame rate without having to consider the noise interference problem of the two-phase stepper motor.

[0006] Technical solution: The ultrasonic volume probe circuit provided by the present invention includes an adjustment unit, an input unit, and a transmission unit;

[0007] The regulating unit is used to regulate the output power level of the circuit to prevent the motor from losing step due to excessive load, and comprises a fourth operational amplifier, a sixth negative feedback circuit, a first multiplication circuit, a second multiplication circuit, an analog switch, a holding capacitor, an input resistor, and a zero-crossing detector;

[0008] The analog switch is connected to the zero-crossing detector, and the analog switch is also connected to one end of the input resistor through a holding capacitor. The other end of the input resistor is connected to the output of the fourth operational amplifier through a sixth negative feedback circuit. The non-inverting input of the fourth operational amplifier is grounded. The output of the fourth operational amplifier is connected to the input of the first multiplication circuit. The output of the fourth operational amplifier is also connected to the input of the second multiplication circuit.

[0009] When the analog switch is closed, the holding capacitor is used to convert the phase of the sinusoidal wave electrical signal generated when zero-crossing detection is triggered, that is, when the ultrasonic volume probe circuit is at a high level, into a DC voltage signal. The input resistor is used to limit the discharge of the holding capacitor and reduce voltage ripple. The fourth operational amplifier is used to receive and amplify the DC voltage signal and output the amplified DC voltage signal. The sixth negative feedback circuit is used to adjust the gain effect of the fourth operational amplifier. The first multiplication circuit and the second multiplication circuit are used to receive and calculate the amplified DC voltage signal and output the adjusted electrical signal to the input unit.

[0010] The input unit is used to receive the regulated electrical signal and provide a reference voltage, and includes a first operational amplifier and a first negative feedback circuit. The first operational amplifier is used to receive the regulated electrical signal, amplify the regulated electrical signal for the first time, and output the amplified electrical signal to the transmission unit. The first negative feedback circuit is used to adjust the gain effect of the first operational amplifier. The inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the first negative feedback circuit, and the non-inverting input terminal of the first operational amplifier is grounded.

[0011] The transmission unit is used to receive the first amplified electrical signal and transmit the first amplified electrical signal, and includes a second operational amplifier, a third operational amplifier, a second negative feedback circuit, a third negative feedback circuit, a fourth negative feedback circuit, a fifth negative feedback circuit, a power operational amplifier, a resistor, and a resistor-capacitor network;

[0012] The output end of the first operational amplifier is connected to the output end of the second operational amplifier via a second negative feedback circuit. The second operational amplifier receives the electrical signal after the primary amplification and performs secondary amplification on the electrical signal. The second negative feedback circuit is used to adjust the gain effect of the second operational amplifier. The non-inverting input end of the second operational amplifier is used to receive a sine wave based on the amplitude of the output end of the first operational amplifier, thereby further driving the stepping motor.

[0013] The output end of the second operational amplifier is connected to the inverting input end of the third operational amplifier, the third operational amplifier is used to receive the electrical signal after the second amplification and perform tertiary amplification of the electrical signal, the inverting input end of the third operational amplifier is connected to the output end of the third operational amplifier through a third negative feedback circuit, the third negative feedback circuit is used to adjust the gain effect of the third operational amplifier, the non-inverting input end of the third operational amplifier is grounded, and at the same time, the inverting input end of the third operational amplifier is connected to one end of the fourth negative feedback circuit, the other end of the fourth negative feedback circuit is connected to the circuit output end, the other end of the fourth negative feedback circuit is also connected to one end of the resistor, the other end of the resistor is grounded, the fourth negative feedback circuit and the resistor are used to adjust the gain effect of the third operational amplifier and the power operational amplifier, and the resistor-capacitor network is used to adjust the voltage and current impact in the ultrasonic volume probe circuit;

[0014] The output end of the third operational amplifier is connected to the non-inverting input end of the power operational amplifier, the power operational amplifier is used to receive the electrical signal after the tertiary amplification and perform final amplification of the electrical signal, the inverting input end of the power operational amplifier is connected to the output end of the power operational amplifier via a fifth negative feedback circuit, the fifth negative feedback circuit is used to adjust the gain effect of the power operational amplifier, the output end of the power operational amplifier is connected to the other output end of the circuit, and the output end of the circuit is connected to the other output end of the circuit via a resistor and capacitor network;

[0015] The ultrasonic volume probe circuit comprises a first circuit module and a second circuit module. Both the first circuit module and the second circuit module include an adjustment unit, an input unit, and a transmission unit. The adjustment unit is used to adjust the circuit power level, change the amplitude of the electrical signal of the ultrasonic volume probe circuit, and transmit the adjusted electrical signal. The input unit is used to receive the adjusted electrical signal and provide a reference voltage. The transmission unit is used to receive and transmit the electrical signal after the initial amplification. The first circuit module controls one phase of a two-phase stepper motor, and the second circuit module controls the other phase of the two-phase stepper motor.

[0016] A four-dimensional scanning method for an ultrasonic volume probe circuit comprises the following steps:

[0017] 1) Drive the two-phase stepper motor to reset the probe;

[0018] 2) Determine whether it is a four-dimensional mode, otherwise return to step 1);

[0019] 3) driving the two-phase stepper motor to position the probe;

[0020] 4) Drive the two-phase stepper motor to realize the acceleration control of the two-phase stepper motor;

[0021] 5) Drive the two-phase stepper motor to achieve uniform speed control of the two-phase stepper motor, and at the same time determine whether the sinusoidal period of the input sine wave reaches the set value. If not, continue to control the two-phase stepper motor to rotate at a uniform speed;

[0022] 6) When the sine period of the input sine wave reaches the set value, the two-phase stepper motor is driven to achieve deceleration control of the two-phase stepper motor;

[0023] 7) Drive the two-phase stepper motor to rotate forward or reverse;

[0024] 8) Determine whether it is a four-dimensional mode, if not, return to step 1), if yes, return to step 4).

[0025] Beneficial effects: Compared with the prior art, the present invention has the remarkable feature of realizing an adaptive power circuit through zero-crossing detection and holding capacitance, adjusting the amplitude of the electrical signal according to the load size, thereby adjusting the driving power level, and further controlling the frequency of the input sine wave to realize acceleration control, deceleration control, and uniform speed control of the two-phase stepper motor, so that the ultrasonic volume probe can work continuously, avoiding vibration and other abnormal conditions caused by the sudden start-up of the two-phase stepper motor when the ultrasonic volume probe is working. At the same time, four-dimensional scanning is performed when the two-phase stepper motor is under uniform speed control, and image scanning is realized while the two-phase stepper motor rotates, ensuring the continuity of the image and improving the scanning frame rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the ultrasonic volume probe circuit of the present invention;

[0027] Figure 2 1 is a phase diagram of the two-phase stepping motor of the present invention when it is in forward rotation;

[0028] Figure 3 Schematic diagram of the phases of the two-phase stepping motor in the present invention when controlled in various states;

[0029] Figure 4 It is a flow chart of the four-dimensional scanning method in the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] The present invention provides an ultrasonic volume probe circuit, comprising an adjustment unit, an input unit, and a transmission unit;

[0032] See also Figure 1 As shown, the regulating unit is used to adjust the output power level of the circuit to prevent the motor from losing step due to excessive load, and includes a fourth operational amplifier, a sixth negative feedback circuit, a first multiplication circuit, a second multiplication circuit, an analog switch, a holding capacitor, an input resistor, and a zero-crossing detector;

[0033] The analog switch is connected to the zero-crossing detector, and the analog switch is also connected to one end of the input resistor through the holding capacitor, the other end of the input resistor is connected to the output end of the fourth operational amplifier through the sixth negative feedback circuit, the non-inverting input end of the fourth operational amplifier is grounded, the output end of the fourth operational amplifier is connected to the first multiplication circuit, and the output end of the fourth operational amplifier is also connected to the second multiplication circuit;

[0034] When the analog switch is closed, the holding capacitor is used to convert the phase of the sinusoidal electrical signal generated when zero-crossing detection is triggered, that is, when the ultrasonic volume probe circuit is at a high level (the analog switch input is high and the analog switch is on), into a DC voltage signal. The input resistor is used to limit the discharge of the holding capacitor and reduce voltage ripple. The fourth operational amplifier is used to receive and amplify the DC voltage signal and output the amplified DC voltage signal. The sixth negative feedback circuit is used to adjust the gain effect of the fourth operational amplifier. The first multiplication circuit and the second multiplication circuit are used to receive and amplify the amplified DC voltage signal and output the adjusted electrical signal to the input unit.

[0035] The input unit is used to input an electrical signal and provide a reference voltage, and includes a first operational amplifier and a first negative feedback circuit. The first operational amplifier is used to receive the electrical signal and amplify the electrical signal for the first time. The first negative feedback circuit is used to adjust the gain effect of the first operational amplifier. The inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the first negative feedback circuit. The non-inverting input terminal of the first operational amplifier is grounded.

[0036] The transmission unit is used to receive and transmit the first amplified electrical signal, and includes a second operational amplifier, a third operational amplifier, a second negative feedback circuit, a third negative feedback circuit, a fourth negative feedback circuit, a fifth negative feedback circuit, a power operational amplifier, a resistor, and a resistor-capacitor network;

[0037] The output end of the first operational amplifier is connected to the output end of the second operational amplifier via a second negative feedback circuit. The second operational amplifier receives the electrical signal after the primary amplification and performs secondary amplification on the electrical signal. The second negative feedback circuit is used to adjust the gain effect of the second operational amplifier. The non-inverting input end of the second operational amplifier is used to receive a sine wave based on the amplitude of the output end of the first operational amplifier, thereby further driving the stepping motor.

[0038] The output end of the second operational amplifier is connected to the inverting input end of the third operational amplifier, the third operational amplifier is used to receive the electrical signal after the second amplification and perform tertiary amplification of the electrical signal, the inverting input end of the third operational amplifier is connected to the output end of the third operational amplifier through a third negative feedback circuit, the third negative feedback circuit is used to adjust the gain effect of the third operational amplifier, the non-inverting input end of the third operational amplifier is grounded, and at the same time, the inverting input end of the third operational amplifier is connected to one end of the fourth negative feedback circuit, the other end of the fourth negative feedback circuit is connected to the circuit output end, the other end of the fourth negative feedback circuit is also connected to one end of the resistor, the other end of the resistor is grounded, the fourth negative feedback circuit and the resistor are used to adjust the gain effect of the third operational amplifier and the power operational amplifier, and the resistor-capacitor network is used to adjust the voltage and current impact in the ultrasonic volume probe circuit;

[0039] The output end of the third operational amplifier is connected to the non-inverting input end of the power operational amplifier, the power operational amplifier is used to receive the electrical signal after the tertiary amplification and perform final amplification of the electrical signal, the inverting input end of the power operational amplifier is connected to the output end of the power operational amplifier via a fifth negative feedback circuit, the fifth negative feedback circuit is used to adjust the gain effect of the power operational amplifier, the output end of the power operational amplifier is connected to the other output end of the circuit, and the output end of the circuit is connected to the other output end of the circuit via a resistor and capacitor network;

[0040] The ultrasonic volume probe circuit comprises a first circuit module and a second circuit module, each of which comprises an adjustment unit, an input unit, and a transmission unit. The adjustment unit is used to adjust the circuit power level, change the amplitude of the electrical signal of the ultrasonic volume probe circuit, and transmit the adjusted electrical signal. The input unit is used to receive the adjusted electrical signal and provide a reference voltage. The transmission unit is used to receive the electrical signal after the first amplification and transmit the electrical signal after the first amplification. The first circuit module controls one phase of a two-phase stepper motor, and the second circuit module controls the other phase of the two-phase stepper motor.

[0041] The first operational amplifier, the second operational amplifier, the third operational amplifier, the fourth operational amplifier, the first multiplication circuit, the second multiplication circuit, the analog switch, and the power operational amplifier are all powered by positive and negative voltages.

[0042] See also Figure 2As shown, a reference voltage Vref is given through the inverting input terminal Avref of the first operational amplifier, and a sinusoidal electrical signal Aphasea_o is input to the input terminal of the first multiplication circuit, and a sinusoidal electrical signal Aphaseb_o is input to the input terminal of the second multiplication circuit. The phase difference between the sinusoidal electrical signal Aphasea_o and the sinusoidal electrical signal Aphaseb_o is 90°. The first multiplication circuit and the second multiplication circuit both pass through a deep negative feedback loop consisting of a fourth operational amplifier, a sixth negative feedback circuit, an analog switch, an input resistor, a holding capacitor, and a zero-crossing detector. The first multiplication circuit outputs a sinusoidal wave Aphasea, and the second multiplication circuit outputs a sinusoidal wave Aphaseb. The first multiplication circuit inputs a sinusoidal wave Aphasea based on the output terminal of the first operational amplifier as a reference to the non-inverting input terminal of the second operational amplifier, and the second multiplication circuit inputs a sinusoidal wave Aphaseb based on the output terminal of the first operational amplifier as a reference to the non-inverting input terminal of the second operational amplifier. At the same time, a sinusoidal wave based on the amplitude of the reference voltage Vref at the output terminal of the first operational amplifier is input to the inverting input terminal of the second operational amplifier to drive the stepper motor to rotate.

[0043] The positive input terminal Aphasea of ​​the second operational amplifier in the first circuit module controls the A-phase output of the two-phase stepper motor, and the positive input terminal Aphaseb of the second operational amplifier in the second circuit module controls the B-phase output of the two-phase stepper motor;

[0044] When the phase of the output end of the first circuit module leads the phase of the output end of the second circuit module by 90 degrees, that is, the phase of phase A leads the phase of phase B by 90 degrees, the two-phase stepper motor rotates forward. When the phase of the output end of the second circuit module leads the phase of the output end of the first circuit module by 90 degrees, that is, the phase of phase B leads the phase of phase A by 90 degrees, the two-phase stepper motor rotates reversely.

[0045] See also Figure 3 As shown, the acceleration control, deceleration control, and uniform speed control of the two-phase stepper motor are achieved by controlling the frequency of the input sine wave. The acceleration control and deceleration control of the two-phase stepper motor use four-segment linear acceleration control and deceleration control. The acceleration control and deceleration control processes each consume a sine wave. Each quarter of the sine wave corresponds to a frequency. The frequency calculation formula is as follows:

[0046] Fi=1 / (T0+((T0-TS) / 4)*i)

[0047] Among them, i takes values ​​of 1, 2, 3, and 4, T0 is the initial value of the cycle corresponding to the set sinusoidal wave frequency, and TS is the target value of the cycle corresponding to the sinusoidal wave frequency. When the drive motor accelerates or decelerates, four different frequency values ​​are obtained according to the set target values. These four values ​​correspond to the frequency values ​​of each stage of the four stages of acceleration or deceleration. The frequency increases from small to large during acceleration, and decreases from large to small during deceleration.

[0048] See also Figure 4 As shown, the present invention also provides a four-dimensional scanning method of an ultrasonic volume probe, which is characterized by comprising the following steps:

[0049] 1) Drive the two-phase stepper motor to reset the probe;

[0050] 2) Determine whether it is a four-dimensional mode, otherwise return to step 1);

[0051] 3) driving the two-phase stepper motor to position the probe;

[0052] 4) Drive the two-phase stepper motor to realize the acceleration control of the two-phase stepper motor;

[0053] 5) Drive the two-phase stepper motor to achieve uniform speed control of the two-phase stepper motor, and at the same time determine whether the sinusoidal period of the input sine wave reaches the set value. If not, continue to control the two-phase stepper motor to rotate at a uniform speed;

[0054] 6) When the sine period of the input sine wave reaches the set value, the two-phase stepper motor is driven to achieve deceleration control of the two-phase stepper motor;

[0055] 7) Drive the two-phase stepper motor to rotate forward or reverse;

[0056] 8) Determine whether it is a four-dimensional mode, if not, return to step 1), if yes, return to step 4);

[0057] The four-dimensional scan is performed when the two-phase stepper motor is in constant speed control. Step 5) includes the following steps:

[0058] 5.1) Send 4D scanning parameters;

[0059] 5.2) Determine whether the two-phase stepper motor is in a uniform speed control state and is rotating forward or reverse; otherwise, continue to control the two-phase stepper motor to rotate at a uniform speed;

[0060] 5.3) Start four-dimensional scanning to achieve forward scanning or reverse scanning.

[0061] In summary, the present invention realizes acceleration control, deceleration control, and uniform speed control of the two-phase stepper motor by controlling the frequency of the input sine wave, so that the ultrasonic volume probe can work continuously, avoiding the noise interference problem of the two-phase stepper motor when the ultrasonic volume probe is working. At the same time, four-dimensional scanning is performed when the two-phase stepper motor is under uniform speed control, and image scanning is realized while the two-phase stepper motor rotates, ensuring image continuity and improving the scanning frame rate.

Claims

1. An ultrasonic volume probe circuit, characterized in that: Contains adjustment unit, input unit, and transmission unit; The regulating unit is used to regulate the output power level of the circuit to prevent the motor from losing step due to excessive load, and comprises a fourth operational amplifier, a sixth negative feedback circuit, a first multiplication circuit, a second multiplication circuit, an analog switch, a holding capacitor, an input resistor, and a zero-crossing detector; The analog switch is connected to the zero-crossing detector, and the analog switch is also connected to one end of the input resistor through a holding capacitor. The other end of the input resistor is connected to the output of the fourth operational amplifier through a sixth negative feedback circuit. The non-inverting input of the fourth operational amplifier is grounded. The output of the fourth operational amplifier is connected to the input of the first multiplication circuit. The output of the fourth operational amplifier is also connected to the input of the second multiplication circuit. When the analog switch is closed, the holding capacitor is used to convert the phase of the sinusoidal wave electrical signal generated when zero-crossing detection is triggered, that is, when the ultrasonic volume probe circuit is at a high level, into a DC voltage signal. The input resistor is used to limit the discharge of the holding capacitor and reduce voltage ripple. The fourth operational amplifier is used to receive and amplify the DC voltage signal and output the amplified DC voltage signal. The sixth negative feedback circuit is used to adjust the gain effect of the fourth operational amplifier. The first multiplication circuit and the second multiplication circuit are used to receive and calculate the amplified DC voltage signal and output the adjusted electrical signal to the input unit. The input unit is used to receive the regulated electrical signal and provide a reference voltage, and includes a first operational amplifier and a first negative feedback circuit. The first operational amplifier is used to receive the regulated electrical signal, amplify the regulated electrical signal for the first time, and output the amplified electrical signal to the transmission unit. The first negative feedback circuit is used to adjust the gain effect of the first operational amplifier. The inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the first negative feedback circuit, and the non-inverting input terminal of the first operational amplifier is grounded. The transmission unit is used to receive the first amplified electrical signal and transmit the first amplified electrical signal, and includes a second operational amplifier, a third operational amplifier, a second negative feedback circuit, a third negative feedback circuit, a fourth negative feedback circuit, a fifth negative feedback circuit, a power operational amplifier, a resistor, and a resistor-capacitor network; The output end of the first operational amplifier is connected to the output end of the second operational amplifier via a second negative feedback circuit. The second operational amplifier receives the electrical signal after the primary amplification and performs secondary amplification on the electrical signal. The second negative feedback circuit is used to adjust the gain effect of the second operational amplifier. The non-inverting input end of the second operational amplifier is used to receive a sine wave based on the amplitude of the output end of the first operational amplifier, thereby further driving the stepping motor. The output end of the second operational amplifier is connected to the inverting input end of the third operational amplifier, the third operational amplifier is used to receive the electrical signal after the second amplification and perform tertiary amplification of the electrical signal, the inverting input end of the third operational amplifier is connected to the output end of the third operational amplifier through a third negative feedback circuit, the third negative feedback circuit is used to adjust the gain effect of the third operational amplifier, the non-inverting input end of the third operational amplifier is grounded, and at the same time, the inverting input end of the third operational amplifier is connected to one end of the fourth negative feedback circuit, the other end of the fourth negative feedback circuit is connected to the circuit output end, the other end of the fourth negative feedback circuit is also connected to one end of the resistor, the other end of the resistor is grounded, the fourth negative feedback circuit and the resistor are used to adjust the gain effect of the third operational amplifier and the power operational amplifier, and the resistor-capacitor network is used to adjust the voltage and current impact in the ultrasonic volume probe circuit; The output end of the third operational amplifier is connected to the non-inverting input end of the power operational amplifier, the power operational amplifier is used to receive the electrical signal after the tertiary amplification and perform final amplification of the electrical signal, the inverting input end of the power operational amplifier is connected to the output end of the power operational amplifier via a fifth negative feedback circuit, the fifth negative feedback circuit is used to adjust the gain effect of the power operational amplifier, the output end of the power operational amplifier is connected to the other output end of the circuit, and the output end of the circuit is connected to the other output end of the circuit via a resistor and capacitor network; The ultrasonic volume probe circuit comprises a first circuit module and a second circuit module, each of which comprises an adjustment unit, an input unit, and a transmission unit. The adjustment unit is used to adjust the circuit power level, change the amplitude of the electrical signal of the ultrasonic volume probe circuit, and transmit the adjusted electrical signal. The input unit is used to receive the adjusted electrical signal and provide a reference voltage. The transmission unit is used to receive the electrical signal after the first amplification and transmit the electrical signal after the first amplification. The first circuit module controls one phase of the two-phase stepping motor, and the second circuit module controls the other phase of the two-phase stepping motor. The circuit is adjusted according to the load size by the adjustment unit. power level, a reference voltage is given to the inverting input terminal of the first operational amplifier, and a sine wave based on the output terminal of the first operational amplifier is input to the positive input terminal of the second operational amplifier, and the sine wave at the positive input terminal of the second operational amplifier in the first circuit module is 90 degrees out of phase with the sine wave at the positive input terminal of the second operational amplifier in the second circuit module, thereby driving the two-phase stepper motor to rotate; when the phase of the output terminal of the first circuit module leads the phase of the output terminal of the second circuit module by 90 degrees, the two-phase stepper motor rotates forward, and when the phase of the output terminal of the second circuit module leads the phase of the output terminal of the first circuit module by 90 degrees, the two-phase stepper motor rotates reversely.

2. The ultrasonic volume probe circuit according to claim 1, characterized in that: The first operational amplifier, the second operational amplifier, the third operational amplifier, the fourth operational amplifier, the first multiplication circuit, the second multiplication circuit, the analog switch, and the power operational amplifier are all powered by positive and negative voltages, and the two-phase stepper motor is directly driven by the power operational amplifier.

3. The ultrasonic volume probe circuit according to claim 1, characterized in that: By controlling the frequency of the input sine wave, acceleration control, deceleration control, and uniform speed control of the two-phase stepping motor are achieved. When the ultrasonic volume probe circuit is in a no-load state, the amplitudes of the input electrical signals of the first circuit module and the second circuit module are both rated values. When the load increases to a critical value, the amplitudes of the input electrical signals of the first circuit module and the second circuit module increase proportionally, and the control motor does not lose step.

4. A four-dimensional scanning method using the ultrasound volume probe circuit according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) Drive the two-phase stepper motor to reset the probe; 2) Determine whether it is a four-dimensional mode, otherwise return to step 1); 3) Drive the two-phase stepper motor to position the probe; 4) Drive the two-phase stepper motor to realize the acceleration control of the two-phase stepper motor; 5) Drive the two-phase stepper motor to achieve uniform speed control of the two-phase stepper motor, and at the same time determine whether the sinusoidal period of the input sine wave reaches the set value. If not, continue to control the two-phase stepper motor to rotate at a uniform speed; 6) When the sine period of the input sine wave reaches the set value, the two-phase stepper motor is driven to achieve deceleration control of the two-phase stepper motor; 7) Drive the two-phase stepper motor to rotate forward or reverse; 8) Determine whether it is a four-dimensional mode, if not, return to step 1), if yes, return to step 4).

5. The four-dimensional scanning method of the ultrasonic volume probe circuit according to claim 4, characterized in that: The four-dimensional scan is performed when the two-phase stepper motor is under constant speed control. Step 5) includes the following steps: 5.1) Send 4D scanning parameters; 5.2) Determine whether the two-phase stepper motor is in a constant speed control state and is rotating forward or reverse. Otherwise, continue to control the two-phase stepper motor to rotate at a constant speed. 5.3) Start the four-dimensional scan so that the ultrasound volume probe can perform forward scanning or reverse scanning.

6. The four-dimensional scanning method of the ultrasonic volume probe circuit according to claim 4, characterized in that: A reference voltage is given by the inverting input terminal of the first operational amplifier, and a sine wave based on the inverting input terminal of the second operational amplifier is input into the positive input terminal of the second operational amplifier. The sine wave at the positive input terminal of the first circuit module and the sine wave at the positive input terminal of the second circuit module are 90 degrees out of phase with each other, thereby driving the two-phase stepping motor to rotate.

7. The four-dimensional scanning method of the ultrasonic volume probe circuit according to claim 6, characterized in that: When the phase of the output end of the first circuit module leads the phase of the output end of the second circuit module by 90 degrees, the two-phase stepper motor rotates forward; when the phase of the output end of the second circuit module leads the phase of the output end of the first circuit module by 90 degrees, the two-phase stepper motor rotates reversely.

8. The four-dimensional scanning method of the ultrasonic volume probe circuit according to claim 6, characterized in that: By controlling the frequency of the input sine wave, acceleration control, deceleration control and constant speed control of the two-phase stepper motor can be achieved.

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