JP2876510B2 - Mechanical scanning ultrasonic probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical scanning ultrasonic probe which scans an ultrasonic beam by a mechanical operation of a transducer.

[0002]

2. Description of the Related Art Conventionally, this type of ultrasonic probe has a structure in which a transducer in the probe is mechanically rotated or oscillated by using a driving force of a motor, thereby scanning an ultrasonic beam. Are doing.

FIG. 2 shows the configuration of a conventional mechanical scanning ultrasonic probe. In FIG. 2, reference numeral 21 denotes a transducer, which is rotatably held by a rotor 22, a rotating shaft 23, and a rotating shaft holder 24. Reference numeral 25 denotes a motor. The rotation of the motor 25 is performed by a worm 26, a worm gear 27, a driving pulley 28, and a timing belt 2.
9, transmitted to the rotor 22 through a rotation transmission system such as the driven pulley 30 or the like. A three-phase (A, B, Z-phase) encoder 31 is attached to the motor 25 as a rotation position detecting means, and detects the rotation speed and rotation angle of the motor 25. The obtained rotation speed and angle information are sent to a control circuit (not shown).
And the scanning operation by the transducer 21 is controlled. Reference numeral 32 denotes an acoustic window, in which an acoustic coupling liquid 33 is filled. Reference numeral 34 denotes an oil seal, which is an acoustic coupling liquid
Is sealed to prevent leakage.

Next, the operation of the above conventional example will be described.
In FIG. 2, when the motor 25 rotates, the worm 2
6, the rotor 22 rotates via the worm gear 27, the driving pulley 28, the timing belt 29 and the driven pulley 30, and the transducer 21 fixed to the outer peripheral surface of the rotor 22 also rotates. The electric signal is transmitted to the transducer 21 while detecting the rotation speed and the rotation angle by the encoder 31 attached to the motor 25, and the ultrasonic wave is transmitted from the transducer 21 to the acoustic coupling liquid 33 and the acoustic window 32.
, And receives the ultrasonic wave reflected from the human body via the reverse path, and displays an image on the ultrasonic diagnostic apparatus main body.

As described above, even in the above-described conventional mechanical scanning ultrasonic probe, it is possible to mechanically scan the ultrasonic waves by rotating the transducer by rotating the motor through the rotational drive transmission system. it can.

[0006]

However, in the above-described conventional ultrasonic probe, the rotation speed and the rotation angle of the motor are detected by the signal of the motor and the encoder directly connected to the motor. Since the rotor is rotated through the system, there is a problem that image distortion and image fluctuation occur.

In the mechanical scanning ultrasonic probe, an acoustic coupling liquid must be sealed in an acoustic window as an acoustic propagation material. However, since there is a mechanism for transmitting the rotational motion of the motor, the transmission system has An oil seal for sealing the liquid must be provided on the way, and there is a problem in increasing the rotational load and reliability.

Further, since there is a drive transmission system, there is no flexibility in the structure of the tip of the probe, and as a result, the shape becomes large, and an ultrasonic probe suitable for a probe for diagnosis in a body cavity. Was difficult to achieve.

The present invention solves such a conventional problem, eliminates the rotational position error of the rotor caused by the rotational drive transmission system, and eliminates the need for a liquid sealing mechanism such as an oil seal. An object of the present invention is to provide a highly reliable mechanical scanning ultrasonic probe that can be sealed.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rotor having a fixed transducer for transmitting and receiving ultrasonic waves and a magnet provided on one of its shafts.
On the other hand, a motor for rotating the rotor is provided by providing a coil, and a rotation position detecting means for detecting the rotation speed and the stop position of the rotor is integrally provided.

According to another aspect of the present invention, the rotational position detecting means comprises a relative position detecting section and a reference position detecting section which are arranged separately from each other, wherein the relative position detecting section is disposed on a side surface of the rotor. Are arranged at intermediate positions of the rotor.

[0012]

According to the present invention, the rotor having the transducer fixed thereto, the motor for driving the rotor, and the rotational position detecting means for detecting the rotation and position of the rotor are integrally formed by the above structure. The mechanism for transmitting the oil to the rotor and the oil seal provided in the middle of the transmission system can be eliminated, and the scanning position of the transducer can be accurately controlled. Leakage of the acoustic coupling liquid can be eliminated.

According to the present invention, the rotational position detecting means is divided into a relative position detecting section and a reference position detecting section, which are separated from each other, the relative position detecting section is disposed on a side surface of the rotor, and the reference position detecting section is provided at an intermediate position of the rotor. By arranging them at the positions, the degree of freedom of the entire rotational position detecting means can be obtained, and the shape of the integrated rotor can be further reduced, thereby realizing a shape that enables easy diagnosis in a body cavity. be able to.

[0014]

FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, transducers 1 and 2 are fixed to the outer peripheral surface of a cylindrical rotor 3 at two positions in a 180-degree direction. Reference numeral 4 denotes a support shaft for the rotor 3, which is fixed to the frame 5. Bearings 6 and 7 rotatably hold the rotor 3 with respect to the support shaft 4 via a relative position detecting magnet 11 and a slip ring 15, respectively. Reference numeral 8 denotes a motor coil fixed to the support shaft 4 inside the rotor 3. Reference numerals 9 and 10 denote motor magnets which are divided into two parts on the inner peripheral surface of the rotor 3 and fixed to face each other. An outer rotor type motor is constituted by the motor coil 8 and the motor magnets 9 and 10. Reference numeral 11 denotes a magnet for relative position detection (encoder A, B phase signal) fixed to one side surface of the rotor 3. 12
Is a relative position detecting MR sensor, which is mounted on the frame 5 with its position adjusted so as to face the relative position detecting magnet 11. The magnet 11 and the MR sensor 12 constitute a relative position detecting unit. Reference numeral 13 denotes a reference position detecting (encoder Z-phase signal) magnet, which is fixed between the transducers 1 and 2 on the outer peripheral surface of the rotor 3. Reference numeral 14 denotes a reference position detecting MR sensor, which is mounted on the frame 5 with its position adjusted so as to face the reference position detecting magnet 13 once per rotation.
The magnet 13 and the MR sensor 14 constitute a reference position detecting unit. Reference numeral 15 denotes a slip ring fixed to the other side surface of the rotor 3, and each conductive ring is connected to the transducers 1 and 2. Reference numeral 16 denotes a brush attached to the slip ring 15, which contacts the respective conductive rings of the slip ring 15 and is connected to a control circuit via a signal line 17. Reference numeral 18 denotes an acoustic window attached to the frame 5 so as to seal and cover these members, and the inside thereof is filled with an acoustic coupling liquid 19.

Next, the operation of the above embodiment will be described.
When a current flows from a current source (not shown) to the motor coil 8, a rotational force is generated in the motor magnets 9 and 10, and the rotor 3 is rotated by the driving force. The rotational position of the rotor 3 is determined by a relative position detecting magnet 11 attached to a side surface of the rotor 3.
And a relative position detecting MR sensor 12 attached to the frame 5 to detect a relative rotation angle, and a reference position detecting magnet 13 attached to the outer peripheral surface of the rotor 3.
The absolute value of the rotation angle of the rotor 3 is detected by the reference position detecting MR sensor 14 attached to the frame 5. At this time, since the absolute value of the rotation angle of the rotor 3 cannot be detected only by the two-phase incremental encoders of the A-phase and the B-phase, the Z-phase MR sensor 14 and the Z-phase magnet 1
3, the rotation angle reference of the rotor 3 is determined. By controlling the energization of the motor coil 8 based on the obtained rotation angle information of the rotor 3 and controlling the rotation speed or positioning stop of the rotor 3, the scanning of the transducers 1 and 2 fixed to the rotor 3 can be performed. I do. When a voltage is applied to the transducers 1 and 2 via the signal line 17, the brush 16 and the slip ring 15 during the scanning operation of the transducers 1 and 2, ultrasonic waves are emitted from the transducers 1 and 2. This ultrasonic wave is launched into the human body through the acoustic coupling liquid 19 and the acoustic window 18, and the ultrasonic wave reflected from the human body is converted into an electric signal by the transducers 1 and 2 through the above-mentioned path in reverse, and is shown in FIG. The signal is sent to the ultrasonic diagnostic apparatus main body through a signal transmission path that is not performed, and is displayed as an ultrasonic image.

The incremental encoders of A and B phases (two phases) each composed of a magnet 11 for detecting a relative position and an MR sensor 12 have a value of 1 in accordance with the resolution of rotation angle detection.
Hundreds of pulses of signal appear at regular intervals during rotation,
The Z-phase signal from the reference position detection composed of the magnet 13 for reference position detection and the MR sensor 14 generates only one pulse during one rotation. Here, the Z-phase MR sensor 14 is A,
If it is to be arranged at the same position as the B-phase MR sensor 12, only the Z-phase magnet 13 needs to have the same physical dimensions as the A and B-phase magnets 11. Twice the size of the above embodiment is required.

As described above, according to the above embodiment, the scanning operation of the transducers 1 and 2 is controlled by the motor and the rotational position detector integrated with the rotor 3 to which the transducers 1 and 2 are fixed. An ultrasonic probe that does not require a mechanism for transmitting to the rotor, has a simple structure, is small, lightweight, and has high reliability can be realized. In addition, since the motor serving as the driving source and the rotational position detecting unit are integrated with the rotor 3, there is no rotational position error due to component accuracy or assembly accuracy of the drive transmission system such as eccentricity of the gear, and there is no distortion or vibration. No ultrasound images can be obtained. Furthermore, since a rotary drive transmission system is not required, an oil seal for sealing the acoustic coupling liquid is not required, so that the load of the rotational motion caused by the oil seal can be reduced and liquid leakage can be prevented. Furthermore, since the magnet 11 and the MR sensor 12 for detecting the relative position and the magnet 13 and the MR sensor 14 for detecting the reference position are arranged apart from each other, the size of the magnet 11 can be reduced, and the size of the probe can be reduced. The shape can be further reduced.

[0018]

According to the present invention, as is apparent from the above embodiment, a rotor having a fixed transducer, a motor for driving the transducer, and a rotational position detecting means for detecting the rotation and position of the rotor are integrally formed. Therefore, a mechanism for transmitting the rotation of the motor to the rotor and an oil seal provided in the middle of the transmission system can be eliminated, and image distortion and image shaking caused by the rotation drive transmission system can be eliminated, and Rotational load caused by the oil seal and leakage of the acoustic coupling liquid from the oil seal can be eliminated.

According to the present invention, the rotational position detecting means is divided into a relative position detecting section and a reference position detecting section, which are separated from each other, the relative position detecting section is arranged on a side surface of the rotor, and the reference position detecting section is provided at an intermediate position of the rotor. The ultrasonic probe, which has a degree of freedom in the shape of the entire rotation position detecting means, can be further reduced in the shape of the integrated rotor, and can easily perform a diagnosis in a body cavity or the like. Can be realized.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a mechanical scanning ultrasonic probe according to an embodiment of the present invention. FIG. 1B is a cross-sectional view taken along line bb in FIG.

FIG. 2 is a cross-sectional view of a conventional mechanical scanning ultrasonic probe.

[Explanation of symbols]

 1, 2 Transducer 3 Rotor 4 Support shaft 5 Frame 6, 7 Bearing 8 Motor coil 9, 10 Motor magnet 11 Magnet for relative position detection 12 MR sensor for relative position detection 13 Magnet for reference position detection 14 MR sensor for reference position detection 15 Slip ring 16 Brush 17 Signal line 18 Acoustic window 19 Acoustic coupling liquid

Continuation of the front page (72) Inventor Koki Kikuchi 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Inside Matsushita Communication Industrial Co., Ltd. (72) Inventor Wataru Tokunaga Wataru Tsunashima 4-chome, Kohoku-ku, Yokohama, Kanagawa Prefecture No. 3 No. 1 Matsushita Communication Industrial Co., Ltd. (56) References JP-A-64-27538 (JP, A) JP-A-63-21046 (JP, A) JP-A-58-109039 (JP, A) 60-55931 (JP, A) Fully open sho 59-14608 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) A61B 8/00-8/15 G01N 29/00-29 / 28

Claims (2)

(57) [Claims] A magnet provided on one of a shaft and a rotor to which a transducer for transmitting and receiving ultrasonic waves is fixed;
In a mechanical scanning ultrasonic probe integrally provided with a coil on the other side to constitute a motor for rotating the rotor and integrally provided with a rotational position detecting means for detecting a rotational speed and a stop position of the rotor, The position detecting means is
A mechanical scan comprising a relative position detecting unit and a reference position detecting unit arranged separately from each other, wherein the relative position detecting unit is disposed on a side surface of the rotor, and the reference position detecting unit is disposed at an intermediate position of the rotor. Type ultrasonic probe. 2. A relative position detecting unit comprising: a magnet provided on a side surface of a rotor; and an MR sensor provided on a frame supporting a shaft of the rotor so as to face the magnet,
A mechanical scanning ultrasonic probe in which a reference position detection unit includes a magnet provided on an outer peripheral surface at an intermediate position of a rotor, and an MR sensor provided on the frame so as to face the magnet.