JP4468480B1 - Ultrasonic probe - Google Patents

Abstract

An operation sound during operation is reduced to eliminate discomfort for a patient, and a rotation angle detection mechanism of a piezoelectric element group is simplified.
SOLUTION: A piezoelectric element group 1 in which a plurality of strip-shaped piezoelectric elements 1a are arranged in a major axis direction, and a rotation mechanism section 2 that swings the piezoelectric element group 1 left and right in the minor axis direction around the major axis direction. The rotating mechanism 2 includes a first bevel gear 8a having a circular arc shape in plan view, a second bevel gear 8b that meshes with the first bevel gear 8a and rotates in the horizontal direction, and a second bevel gear 8b. A drive motor 10 that rotates through the rotation shaft 9 and a reference position detection sensor 20 that detects a reference position in the minor axis direction of the piezoelectric element group 1 are provided. The rotation shaft 9 of the second bevel gear 8b and the drive motor 10 are provided. The rotation shaft 10 a is connected to a pulley using a timing belt 16.
[Selection] Figure 1

Description

  The present invention relates to an ultrasonic probe (hereinafter referred to as a “short axis swing probe”) that obtains a stereoscopic image by swinging a piezoelectric element group that is an ultrasonic generation source in a short axis direction, and in particular. In addition to having a simple mechanism that eliminates patient discomfort by reducing the operation sound during the operation, the mechanism for detecting the rotation angle of the piezoelectric element group is simplified, making it easy to detect the reference position for the subject It relates to the short axis swing probe.

  The short-axis swing probe is known to obtain a three-dimensional (3D) image by electronically scanning a piezoelectric element group in the major axis direction and mechanically scanning (swing) in the minor axis direction. [Japanese Unexamined Patent Application Publication No. 2006-346125 (Patent Document 1, Conventional Example 1), Japanese Unexamined Patent Application Publication No. 2003-175033 (Patent Document 2, Conventional Example 2), German Published Patent Specification DE 3405537A1 (Patent Document 3, Conventional Example 3) ]].

  Compared to a matrix type probe or the like that, for example, a piezoelectric probe is arranged vertically and horizontally and electronically scans in a two-dimensional direction, the short axis swing probe can be easily used for wiring (connection) and a scanning circuit. It has been put into practical use.

  5A and 5B are diagrams for explaining the short axis swing probe of Conventional Example 1. FIG. 5A is a cross-sectional view in the major axis direction, and FIG. 5B is a cross-sectional view in the minor axis direction. .

  The short axis swing probe of the conventional example 1 includes a piezoelectric element group 1 and a rotation mechanism 2 as shown in FIGS. 5 (a) and 5 (b). The piezoelectric element group 1 is arranged side by side on a backing material (not shown) with the width direction of the plurality of strip-like piezoelectric elements 1a aligned with the major axis direction and the length direction as the minor axis direction. The backing material is fixed on a base 4 having a convex curved surface in the major axis direction, and the piezoelectric element group 1 is configured to bend in a convex shape (convex shape) in the major axis direction.

  And the flexible substrate 5 electrically connected to the piezoelectric element group 1 over the entire region in the major axis direction is led out downward from one end side in the minor axis direction. Here, the conductive path 5a of the flexible substrate 5 (partially shown by broken lines in FIG. 5A) and a drive electrode (not shown) of the piezoelectric element 1a are electrically connected. In FIGS. 5A and 5B, both are directly connected. However, for example, the drive electrode of the piezoelectric element 1a and the conductive path 5a may be indirectly connected by a silver foil and a conductive wire.

  In Conventional Example 1, as shown in FIG. 5A, the rotation mechanism unit 2 is attached to the holding plate 6, the case 7, the first bevel gear 8a, the second bevel gear 8b, the rotation shaft 9, and the frame member 7b. Drive motor 10 provided. The holding plate 6 has legs 6a and 6b on the lower surface on both ends in the major axis direction, and fixes the base 4 supporting the piezoelectric element group 1 to the upper surface. The center shafts 11a and 11b have bearings 11c and 11b in the long axis direction (on the horizontal straight line XX shown in FIG. 5A) penetrating the leg portions 6a and 6b. 11d. The leg portions 6a and 6b are rotatable with respect to the central axes 11a and 11b.

  Furthermore, the case 7 has a concave cross section with its upper surface opened, and the projecting ends of the central shafts 11 a and 11 b projecting from the leg portions 6 a and 6 b are coupled (fixed) to the peripheral wall of the case 7. A slit 12 (see FIG. 5B) is formed on the bottom wall of the case 7 in the major axis direction, and the flexible substrate 5 from the piezoelectric element group 1 is led out of the frame member 7b. The slit 12 is sealed by embedding, for example, a synthetic resin 13.

  The first bevel gear 8a is attached to the inner surface of the leg portion 6a below the central axes 11a, 11b of one leg portion 6a by screws or the like, and has arc-shaped (fan-shaped) teeth with the perpendicular lower end as a vertex. . The second bevel gear 8b is pivotally attached to the rotary shaft 9 in the vertical direction perpendicular to the central axes 11a and 11b (straight line XX), meshed with the first bevel gear 8a and horizontally (X− Rotate in the X direction). The rotary shaft 9 is sealed from the bottom wall of the case 7 by a seal ring 14a and led out of the frame member 7, and the other end is gear-coupled using the drive motor 10 and, for example, metal spur gears 15a and 15b. (Mesh).

  In Conventional Example 1, the first bevel gear 8a and the second bevel gear 8b are made of a metal material, and the diameters of the circles when the teeth of the first bevel gear 8a in an arc shape in plan view are arranged in a circle are as follows: The diameter is larger than the diameter of the second bevel gear 8b. Further, the diameter of the metal gear 15 a fixed to the rotating shaft 9 is made larger than the diameter of the metal gear 15 b of the drive motor 10.

  With these configurations, by increasing the gear ratio from the drive motor 10 to the first bevel gear 8a, the rotational force (torque) of the drive motor 10 is maintained to be large and the rotational force is driven and transmitted to the first bevel gear 8a. To do. The case 7 is provided with a cover (not shown) (see reference numeral 7a shown in FIG. 1) that covers the piezoelectric element group 1. The piezoelectric element group 1 and the like are hermetically sealed, and oil or the like is enclosed in the case 7 sealed by the cover. The ultrasonic medium is filled.

  In Conventional Example 1, the first bevel gear 8a is moved in the vertical plane by rotating / rotating the rotation (swing) motor 10 to the left and right in the horizontal direction of the second bevel gear 8b constituting the rotation mechanism unit 2. On the other hand, it oscillates obliquely upward and downward on the left and right with the vertex at the center. That is, the first bevel gear 8a swings by rotating, for example, 75 ° to the left and right in the vertical direction around the apex. The leg portions 6a and 6b of the holding plate 6 rotate and swing left and right with respect to the central axes 11a and 11b, while the piezoelectric element group 1 has a short axis direction opposite to the first bevel gear 8a. Rotates and swings left and right.

  In the second conventional example, power is directly transmitted to the drive motor and the rotating shaft on the piezoelectric element side by pulley coupling using a belt.

  Furthermore, in Conventional Example 3, in the ultrasonic probe, the rotating shaft is rotated by pulley connection using a belt by two drive motors, and a first bevel gear made of a metal material is fixed to the tip of the rotating shaft, The first bevel gear rotates the second bevel gear made of a metal material meshed with the first bevel gear, and rotates and swings the ultrasonic vibration head fixed to the tip of the second bevel gear.

JP 2006-346125 A JP 2003-175033 A German published patent specification DE 3405537 A1

  However, since the short axis swing probe of the first conventional example having the above-described configuration uses the first bevel gear 8a and the second bevel gear 8b formed from a metal material, the meshing of these metal gears. Occasionally, a unique metallic sound is generated, and there is a problem that makes the doctor (operator) and particularly the patient uncomfortable during the operation.

  Moreover, in the said prior art example 2, since a motive power is directly transmitted with the motor and the rotating shaft by the side of a piezoelectric element by the pulley coupling | bonding which used the belt, generation | occurrence | production of a metallic sound is eliminated. However, in the conventional example 2, as described above, in addition to the gear directly connected to the drive motor, it is not coupled in two stages using a bevel gear, so that the rotational force of the motor is reliably transmitted to the rotating shaft on the piezoelectric element side. In order to achieve this, it is necessary to increase the diameter ratio of the pulley. Therefore, since the pulley on the piezoelectric element side becomes large, it is difficult to design a compact probe with a small size.

  Further, in the conventional example 3, although the rotating shaft is rotated by pulley coupling using a belt, a pair of bevel gears made of a metal material are used for rotation / oscillation of the ultrasonic vibration head. There was a problem that metal noise was generated when the pair of bevel gears meshed and rotated.

  The present invention eliminates the discomfort to the operator and the patient by suppressing the generation of a metallic sound at the time of meshing of the gear, and the short axis swing that makes it easy to set the reference position of the piezoelectric element group with respect to the subject. The purpose is to provide a probe.

  In order to solve the above-described problems, an ultrasonic probe according to the present invention includes a piezoelectric element group in which a plurality of strip-shaped piezoelectric elements are arranged in the major axis direction, and the piezoelectric element group centered on the major axis direction. A rotating mechanism portion that swings left and right in the short axis direction, and the rotating mechanism portion meshes with the first bevel gear having a circular arc shape in plan view and the first bevel gear to rotate in the horizontal direction. An ultrasonic probe comprising: a double bevel gear; a drive motor that rotates the second bevel gear via a rotary shaft; and a reference position detection sensor that detects a reference position in the minor axis direction of the piezoelectric element group. And the rotation shaft of the second bevel gear and the rotation shaft of the drive motor are pulley-coupled using a timing belt, the first bevel gear is formed of a synthetic resin, and the light shielding portion is formed on the rotation shaft. Before having a boundary area between the light transmission part An optical rotating plate of a reference position detection sensor is coupled, and the light shielding portion and the light transmitting portion are continuously formed at a predetermined angle in opposite directions from the center of the optical rotating plate with respect to the boundary region. And the optical rotating plate rotates less than the predetermined angle with respect to the boundary region, and the boundary region is detected by light transmission or shielding by the light shielding unit and the light transmission unit, and is thus detected. The reference position of the piezoelectric element group with respect to the subject is set based on the boundary region.

  According to such a configuration, since the rotation shaft of the second bevel gear and the drive motor are pulley-coupled using a belt and the first bevel gear is made of synthetic resin, the metal gears do not mesh with each other. No special metallic sound is generated during rotation. This eliminates discomfort for the operator of the ultrasonic probe and particularly the patient, and makes it easy to set the reference position for the subject of the piezoelectric element group, greatly increasing the medical burden on the operator. It is reduced.

FIG. 1A is a longitudinal sectional view in a major axis direction, and FIG. 1B is a transverse sectional view in a minor axis direction, illustrating an embodiment of a short axis swing probe according to the present invention. . It is a perspective view of the short axis rocking probe of the present invention shown in FIG. FIG. 2 is a perspective view of a reference position sensor of the short axis swing probe of the present invention shown in FIG. 1. FIG. 4 is a plan view for explaining the operation of the reference position sensor shown in FIG. 3, particularly showing the rotation position of the optical rotation plate of the reference position sensor, and FIG. 4 (a) shows the reference position P of the optical rotation plate counterclockwise. theta _2, in FIG. 4 (b) shows a state where the reference position P is rotated theta ₁ clockwise. FIGS. 5A and 5B are diagrams for explaining a conventional example of a short axis swing probe, in which FIG. 5A is a cross-sectional view in the long axis direction, and FIG. 5B is a cross-sectional view in the short axis direction.

  FIG. 1A illustrates an embodiment of the short axis swing probe according to the present invention. FIG. 1B is a sectional view of the minor axis direction, and FIG. Is a perspective view thereof.

  The short axis swing probe of the present invention includes a piezoelectric element group 1, a rotation mechanism portion 2 thereof, and a reference position detection sensor 20.

  The piezoelectric element group 1 is formed in a convex shape by arranging on a backing material (not shown) mounted on the upper surface of the base 4 with the width direction of a large number of piezoelectric elements 1a as the major axis direction. The flexible substrate 5 electrically connected via the path 5a (partially omitted by a broken line in FIG. 1A) is probed through the slit 12 in which the synthetic resin 13 is embedded and sealed. It is led out to the outside of the case 7 from one end side in the minor axis direction of the child.

  The rotation mechanism 2 includes a holding plate 6 that fixes the piezoelectric element group 1 on the upper surface, and center shafts 11a and 11b that slide freely on bearings 11c and 11d via leg portions 6a and 6b on both ends of the holding plate 6, respectively. The case 7 having a concave cross section provided with a first ring gear 8a and a first bevel gear 8a, which are provided below one leg 6a of the holding plate 6 and have a circular arc (fan) shape in plan view, are engaged with the seal ring 14a. The rotating shaft 9 sealed via the second bevel gear 8b is sealed and led out from the bottom wall of the case 7 to the outside of the frame member 7b, and the drive motor (stepping motor) 10 is attached to the frame body 7b.

  Here, the fan-shaped first bevel gear 8a on the driven side is made of a synthetic resin, and the second bevel gear 8b on the driving side that requires a driving torque and requires an appropriate mechanical strength is made of metal. Further, the rotary shaft 9 of the second bevel gear 8 b and the rotary shaft 10 a of the drive motor 10 (stepping motor) are coupled to a timing pulley using a belt 16.

  Here, as a material of the first bevel gear 8a made of synthetic resin, polyacetal resin (abbreviated as POM) is used. POM resin is an engineering plastic that is superior in strength, elastic modulus, impact resistance, sliding properties, etc. because it contains both amorphous and crystalline parts, and is lighter than metal bevel gears. It is also excellent in oil resistance and moldability.

  In the probe of the present invention, since the case 7 sealed with the cover 7a is used by filling an ultrasonic medium such as oil, the first bevel gear 8a made of POM resin having excellent oil resistance is used. It is suitable as a drive member for a kind of probe.

  Here, the diameter of the first bevel gear 8a is made larger than the diameter of the second bevel gear 8b, the pulley 17a of the rotary shaft 9 is made larger than the pulley 17b of the drive motor 10 (the gear ratio is increased), and the drive The rotational force of the motor 10 is increased. The pulleys 17a and 17b are provided with concave and convex grooves on the outer surfaces of the pulleys 17a and 17b and the meshing surfaces of the timing belt 16 and the pulleys 17a and 17b. Ensure power transmission. Here, in the timing pulley / belt mechanism that is the first stage drive means, the reduction ratio is, for example, 2.8: 1, and in the bevel gear drive mechanism that is the second stage drive means, the reduction ratio. For example, 2.1: 1, a sufficient reduction ratio can be obtained by a combination of both drive mechanisms.

  According to such a configuration, the rotation shaft 9 of the second bevel gear 8b and the rotation shaft 10a of the drive motor 10 are pulley-coupled using the timing belt 16 and the timing pulleys 17a and 17b. Thus, unlike the prior art, for example, uncomfortable metal noises are not generated when the metal gears 15a and 15b shown in FIG. Further, since the first bevel gear 8a is made of synthetic resin and the second bevel gear 8b is made of metal, the metal sound at the time of meshing can be reduced also in this case. Therefore, it is possible to suppress the generation of a metallic sound during the operation of the probe and to eliminate discomfort for the operator, particularly the patient.

  That is, in the probe of the present invention, the rotation (oscillation) motor 10 swings and rotates to the left and right in the horizontal direction of the second bevel gear 8b that constitutes the rotation mechanism unit 2, so that the swing rotation is the pulley. The rotation shaft 9 is swung from 17b via the timing belt 16 to the pulley 17a, and the first bevel gear 8a is swung obliquely upward and leftward with respect to the vertical plane. That is, the first bevel gear 8a swings, for example, by rotating 75 ° (excluding the acceleration / deceleration range at the time of swinging left and right) around the vertex in the vertical direction. The leg portions 6a and 6b of the holding plate 6 rotate and swing left and right with respect to the central shafts 11a and 11b. On the other hand, the piezoelectric element group 1 has a short axis direction opposite to the first bevel gear 8a. Rotates and swings left and right. Then, a rotation angle in the minor axis direction of the piezoelectric element group 1 from the reference position is detected by a reference position detection sensor of the rotary shaft 9 described later, and biological information from the subject (living body) is accurately obtained. .

  Furthermore, the short axis swing probe of the present invention is characterized by including the reference position detection sensor 20 shown in FIG.

  That is, as shown in FIG. 3, the reference position detection sensor 20 includes an optical rotating plate 21a and a cross section integrally coupled to a rotating shaft 9 that drives the first bevel gear 8a via the second bevel gear 8b. It has a photo detector 20b attached to the bottom rear surface of the frame 7b shown in FIG.

  The optical rotating plate 21a has a semicircular (half-moon) shape in plan view, and includes a light shielding portion 21a and a light transmitting portion 21b (a region indicated by a chain line in FIG. 3), and a boundary formed by a linear corner between the two. It has area P. The light shielding portion 21a and the light transmitting portion 21b are continuously formed with an interval of 180 degrees in the opposite direction from the rotation center of the optical rotating plate 21a with the boundary region P as a reference.

  The optical rotating plate 21a shown in FIG. 3 is restricted from rotating and swinging in an angle range of less than 180 degrees in opposite directions with respect to the boundary region P. Here, the rotation is restricted within an angle of 90 degrees in opposite directions. This angle limitation depends on the rotation of the rotary shaft 9 geared to the drive motor 10 shown in FIG. Further, the light detector 20b is fixed to the frame body 20c shown in FIG. 1A through a shim or the like with a stopper such as a screw, and the outer peripheral portion of the optical rotating plate 21a is formed in the shape of the light detector 20b. (Character-shaped cross section) It is positioned to rotate in the space S.

  Here, the initial position (reference position) of the optical rotating plate 21a is such that the boundary region P is located in the space S of the U-shaped portion of the light detector 20b, and light between the light transmitting and receiving portions of the light detector 20b. A transmission or non-transmission switching point (ON or OFF). In this case, the piezoelectric element group 1 shown in FIG. 1 is arranged at the reference position where the center line that bisects the minor axis direction from the rotation center coincides with the center of the cover 7a shown in FIG. .

In such a short axis swing probe of the present invention, the operation of the short axis swing probe is started by pressing a start button (not shown). Here, before the operation of the probe starts, for example, as shown in FIG. 4A, the boundary region P of the optical rotating plate 20a is rotated counterclockwise within 90 degrees (θ ₂ ) from the reference position. Suppose that the light shielding portion 21a is located in the space S of the photodetector 20b. In this case, by pressing the start button, first, the light detector 20b catches the presence of the light shielding part 21a and detects the shielding signal. Then, based on this shielding signal, the drive motor 10 is driven to rotate the optical rotating plate 20a clockwise. Next, a boundary region P of the optical rotating plate 20a that serves as a light shielding or transmission boundary is detected. Then, the drive motor 10 is stopped and set to the reference position.

Further, before the operation of the probe is started, as shown in FIG. 4B, the boundary region P of the optical rotating plate 20a is rotated within 90 degrees (θ ₁ ) clockwise from the reference position to detect the light. It is assumed that the light transmission part 21b is located in the space part S of the container 20b. In this case, by pressing the start button, first, the light detector 20b detects a transmission signal. Then, based on the detected transmission signal, the drive motor 10 is driven to rotate the optical rotating plate 20a counterclockwise. Next, the boundary region P is set to the reference position in the same manner.

  By these operations, the piezoelectric element group 1 is set to the reference position on the front face of the center that coincides with the center of the cover 7a. Then, the piezoelectric element group 1 rotates and swings left and right from the reference position to transmit and receive ultrasonic waves to the detected body by the rotation mechanism unit 3 interlocked with the drive motor 10 and the rotation shaft 9 shown in FIG. Then, a three-dimensional (3D) image of the subject can be obtained from the relationship between the preset number of positive and negative pulses and the rotation angle. For example, the piezoelectric element group 1 rotates in the right direction when the pulse is positive, and in the left direction when the pulse is negative.

  That is, according to such a configuration, the optical rotating plate 21a rotates and swings while being limited to within 90 degrees in directions opposite to each other with the boundary region P as a reference. Therefore, when the optical detector 20b detects a shielding signal or transmission signal depending on the rotation position of the optical rotating plate 21a, and the optical rotating plate 21a rotates clockwise or counterclockwise as set in advance, the rotation is performed. Only the boundary region P on one end side exists in the corner. Therefore, the boundary region P can be reliably detected, and the reference position of the piezoelectric element group 1 can be easily set by a simple mechanism.

  Therefore, the reference position of the piezoelectric element group 1 is accurately set, and biological information from the accurate position of the subject can be obtained.

DESCRIPTION OF SYMBOLS 1 Piezoelectric element group 2 Rotation mechanism part 3 Bevel gear part 4 Base 5 Flexible board 6 Holding plate 7 Case 7a Cover 7b Frame member 8a First bevel gear (made of synthetic resin)
8b Second bevel gear (made of metal)
9 Rotating shaft 10 Drive motor (stepping motor)
12 Slit 14a, 14b Seal ring 16 Timing belt 17a, 17b Pulley 20 Reference position detection sensor 20a Optical rotating plate 20b Optical detector 20c Frame 21a Light shielding part 21b Light transmission part P Boundary area L Ultrasonic propagation medium (for example, oil)

Claims (1)

A plurality of strip-shaped piezoelectric elements arranged in the major axis direction, a piezoelectric element group housed in a case, and a rotation mechanism that swings the piezoelectric element group from side to side in the minor axis direction around the major axis direction A first bevel gear having a circular arc shape in plan view, a second bevel gear that meshes with the first bevel gear and rotates in the horizontal direction, and rotates the second bevel gear. In an ultrasonic probe comprising: a drive motor that rotates through a shaft; and a reference position detection sensor that detects a reference position in the short axis direction of the piezoelectric element group, the rotation shaft of the second bevel gear and the The rotation shaft of the drive motor is coupled with a pulley using a timing belt, the first bevel gear is made of synthetic resin, and the second bevel gear is made of metal, and the light shielding portion and light are formed on the rotation shaft. Has a boundary area with the transmission part Serial reference position viewed semicircular were optical rotation plate detecting sensor is coupled to the semi-circular portion of the light shielding portion is the semi-circular optical rotating plate, also said the light transmitting portions of the semi-circular optical rotating plate A portion other than a semicircular portion is continuously formed 180 degrees from the center of the optical rotating plate in opposite directions with respect to the boundary region, and the optical rotating plate is less than 180 degrees with respect to the boundary region. And the boundary region is detected by a light detector having a U-shaped cross section cooperating with the optical rotating plate, so that the transmission or shielding of light by the light shielding part and the light transmitting part is detected. reference position is set to the subject of the piezoelectric element group on the basis of the boundary region Rutotomoni, attaching the bottom frame portion to the rear surface of the case, the rotary mechanism provided in the frame portion, further a bottom rear surface of the frame portion Ultrasound probe, characterized the rotating motor directly and the light detector of the U-shaped section provided frame in the bottom rear surface of the frame portion is provided to each of the frame body, it.

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