JPS62139632A - Rotation controller of ultrasonic probe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotation control device for an ultrasonic probe used in an ultrasonic diagnostic apparatus or the like for obtaining tomographic images of internal organs in the body using ultrasonic waves.

2. Description of the Related Art In general, an ultrasonic diagnostic apparatus obtains tomographic images of internal organs by emitting ultrasonic waves into the body and receiving the reflected waves. To irradiate ultrasonic waves into the body, an ultrasonic transducer called a probe is brought into contact with the body in a direction perpendicular to the desired tomographic plane. This probe has three ultrasonic probes (ultrasonic transmitting elements) so as to divide the circumference near its tip into three equal parts.
Some ultrasonic probes are arranged individually and are rotated by a motor provided in the probe to transmit ultrasonic waves and receive reflected waves from internal organs of the body. .

The following is the third part about the rotation control device of the conventional ultrasonic probe.
This will be explained with reference to the figures.

In FIG. 3, 101, 104, 108, 11
0.

117 is a resistor, 102, 105, 116 is a capacitor, 103, 106, 113, 118, 122
is an inverter circuit, 107 is an exclusive OR circuit (
(hereinafter referred to as EXOR circuit), 109 and 111 are diodes, 112, 119 and 120 are preset counters, 114 and 124 are counters for obtaining an output synchronized with the clock signal, 115 and 123 are latch circuits, and 121 is a Nant gate. circuit, 125 is a phase comparator, 1
26, 128 are operational amplifiers, 143 is a preamplifier, 1
27 and 129 are multiplexer circuits, 130 is a variable resistor, 144 is a motor driver circuit, and 149 is a probe, which is composed of a motor 145, a rotary probe 147, and an encoder 146. 148 is a microconbeater.

Next, the operation of the above conventional example will be explained. encoder 1
46 outputs pulse signals A and B whose phases are shifted by 90 degrees, and these pulse signals A and B are doubled by the gXOR circuit 107, input to the counter 112, and are input to the microconbeater 148 according to the diagnostic purpose. The frequency is divided based on the signal output from the

On the other hand, the television horizontal synchronizing signal is frequency-divided by counters 119 and 120 depending on the diagnostic purpose. The phases of these frequency-divided signals are compared by a phase comparator 125, and a correction signal corresponding to the phase difference is outputted and inputted to an amplifier 143. The amplifier 128 outputs a DC component corresponding to the rotation speed of the motor 145, which is added to the correction signal by the amplifier 143 and input to the motor driver circuit 144. The motor 145 is driven by the output of this motor driver circuit 144, and thereby the probe 147 is rotated in synchronization with the television horizontal synchronization signal.

Problems to be Solved by the Invention However, in the conventional configuration described above, the television horizontal synchronizing signal is input to the motor 145 as it is via the phase comparator 125 without removing the noise component mixed therein. This causes uneven rotation of the ultrasound probe 147.

Furthermore, since the signal from the encoder 146 is not doubled but only frequency-divided when it is input to the phase comparator 125, the synchronization between the TV horizontal synchronization signal and the ultrasound signal from the probe is poor. , the image was blurred and a clear image could not be obtained.

Therefore, an object of the present invention is to provide a rotation control device for an ultrasound probe that can obtain clear images.

Means for solving the problems and technical means of the present invention for solving the above problems include: an encoder connected to a drive motor of a rotary ultrasonic probe and outputting a pulse signal; Means for quadrupling the output pulse signal of the encoder, means for counting a preset signal, and comparing the output signal from the counting means with the TV horizontal synchronization signal to remove noise from the TV horizontal synchronization signal. means for dividing the output signal from the removing means, and comparing the signal frequency-divided by the frequency dividing means and the output signal from the quadrupling means to determine the phase difference between the driving motor and the television. The apparatus includes means for outputting an error corresponding to the synchronization of the horizontal synchronization signal, and means for correcting the error output by the comparison means and controlling the rotation of the drive motor.

For production The effects of the above technical means are as follows.

That is, the signal corresponding to the rotational speed of the ultrasonic probe driving motor is quadrupled and output. On the other hand, the signal outputted by counting preset signals is compared with the television horizontal synchronization signal, and the noise component of the television horizontal synchronization signal is removed and the frequency is divided. This frequency-divided signal and the quadrupled signal are compared, the phase difference is output as an error in synchronization of the drive motor and the TV horizontal synchronization signal, and this error is corrected to control the rotation of the motor. I try to do that. Therefore, uneven rotation of the ultrasound rotor does not occur, and the rotation of the ultrasound probe can be double synchronized with the TV horizontal synchronization signal, resulting in a clear image without image fluctuation caused by ultrasound. be able to.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.

In Figure 1, l, 2.4.5.8.10 are bias resistors, 9 and 11 are noise removal diodes, and 3 and 6
53 is an inverter circuit that inverts the signal; 53 is a quadrupling circuit that quadruples the frequency of the signal;
13, 14 bias resistor 15 and integrating capacitor 1
6. 17.18 is bias resistance,
19 is an inverter circuit, and 54 is a phase-locked loop circuit (hereinafter referred to as a PLL circuit), which includes a phase comparator 20, a loop filter 22, a voltage-controlled oscillator 23, and a preset counter 21. 24 and 25 are preset counters, 26 is a Nant gate circuit, 27 is an inverter circuit, 28 is a phase comparator, 29 is a loop filter circuit, 30 is an operational amplifier, 33 is a variable resistor, 31
, 32 is a multiplexer circuit, 46 is a preamplifier, 47
is a motor driver circuit, 52 is a probe, and motor 4
8, an encoder 49 and a rotary ultrasonic probe 50. 51 is a microcomputer.

Next, the operation of the above embodiment will be explained. An encoder 49 connected to the motor 48 outputs pulse signals A and B having a phase difference of 90 degrees.
When input to the EXOR circuit 7 of the doubling circuit 53, each EX
The signal waveform diagram in the OR circuit 7.12.13.14 is as shown in FIG. That is, due to the delay effect of the integrating circuit including the resistor 15 and the capacitor 16, the EXOR circuit 14 outputs four pulses per period of the signal A, thereby quadrupling the signal. On the other hand, the PLL circuit 54 converts the pulses of the voltage controlled oscillator 23 into the preset counter 21.
The count is counted until the value set by the microcomputer 51 is reached and output. The television horizontal synchronizing signal and the output signal of the preset counter 21 are connected to a phase comparator 2.
0 and outputs the phase difference to the voltage controlled oscillator 23 via the loop filter 22. This PLL circuit 54
This makes it possible to remove noise mixed into the television horizontal synchronization signal. The output of this PLL circuit 54 is frequency-divided by a preset counter 24.25 based on the frequency division ratio set in the microcomputer 51, and then passed through a Nant gate circuit 26 and an inverter circuit 27 to a phase comparator 28.
Output to. The phase comparator 28 compares the output signals of the preset counters 24 and 25 with the output signal of the quadrupling circuit 53 and outputs the phase difference to the loop filter circuit 29. Output as the error for synchronization of the TV horizontal synchronization signal. This error is output from the multiplexer circuit 32 according to the reduction/enlargement ratio set by the microcomputer 51. Then, a DC signal corresponding to the rotation of the motor 48 outputted from the operational amplifier 30 and outputted through the multiplexer circuit 31 controlled by the variable resistor 33 and the microcomputer 51 is combined with the above error component as a reference voltage component. Ru. This composite signal of the reference voltage and error passes through the preamplifier 46 and the motor driver circuit 47 and becomes the rotation control voltage for the motor 48 of the probe 52, thereby driving the motor 48 and rotating the ultrasound probe 50. let

In this way, the rotation of the motor 48 can be controlled so that the ultrasonic probe 50 is rotated in synchronization with the television horizontal synchronization signal. Even if noise components are added to the television horizontal synchronization signal, they can be removed by the PLL circuit 54 as described above.

Also, the phase comparator 20 and phase comparator 28 of the PLL circuit 54
The rotation of the ultrasonic probe is doubly synchronized with the television horizontal synchronization signal, and the frequency of the output of the encoder 49 that detects the rotation speed of the motor 48 is quadrupled by the circuit 5.
3 has quadrupled, refined and subdivided the control, so PLL
Together with the circuit 54, image blur can be reduced.

Note that the circuit shown in FIG. 1 is also a PLL circuit.

Effects of the Invention As is clear from the above description, the present invention quadruples a signal corresponding to the number of revolutions of an ultrasonic probe driving motor using a quadrupling means and outputs the quadrupled signal. On the other hand, the signal outputted by counting preset signals is compared with the television horizontal synchronization signal, and the noise component of the television horizontal synchronization signal is removed and the frequency is divided. This frequency-divided signal and the quadrupled signal are compared, the phase difference is output as an error in synchronization of the drive motor and the TV horizontal synchronization signal, and this error is corrected to control the rotation of the motor. I try to do that.

Therefore, uneven rotation of the ultrasonic probe does not occur, and the rotation of the ultrasonic probe can be double-synchronized with the TV horizontal synchronization signal. By quadrupling the frequency, it is possible to refine and subdivide the control, and it is possible to obtain a clear image without image fluctuation caused by ultrasonic waves.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the ultrasonic probe rotation control device of the present invention, with Figure 1 being a block circuit diagram and Figure 2 quadrupling the encoder output using a quadrupling circuit. The signal waveform diagram in FIG. 3 is a block circuit diagram of a conventional ultrasonic probe rotation control device.ヱ7, 12.13.14...exclusive output circuit (EXOR circuit), 20...phase comparator, 21...
・Preset counter, 22...Loop filter, 2
3... Voltage controlled oscillator, 24, 25... Preset counter, 28... Phase comparator, 29... Loop filter circuit, 30... Operational amplifier, 31, 32...
... Multiplexer circuit, 33 ... Variable resistor, 46
...Preamplifier, 47...Motor driver circuit,
48...Motor, 49...Encoder, 50...
Ultrasonic probe, 51... Microconbeater, 52
. . . Probe, 53 . . . Quadruple circuit, 54 . . . Phase-locked loop circuit (PLL circuit).

Claims (1)

[Claims] An encoder connected to a driving motor of an ultrasonic probe and outputting a pulse signal, means for quadrupling the output pulse signal of this encoder, means for counting a preset signal, and a means for counting a preset signal; means for comparing the output signal of the television horizontal synchronizing signal with the television horizontal synchronizing signal to remove the noise component of the television horizontal synchronizing signal, means for frequency-dividing the output signal from the eliminating means, and a signal frequency-divided by the frequency dividing means. Means for comparing the output signals from the quadrupling means and outputting the phase difference as an error in synchronization of the drive motor and the TV horizontal synchronization signal, and driving after correcting with the error output by the comparison means. 1. A rotation control device for an ultrasonic probe, comprising means for controlling the rotation of a motor.