JP2007185416A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe which can realize the rocking origin return of an ultrasonic vibrator assembly at a high speed and at a low price. <P>SOLUTION: In the ultrasonic probe having the ultrasonic vibrator assembly in which two or more ultrasonic vibrators transmitting and receiving an ultrasound are arranged, a driver which makes the ultrasonic vibrator assembly rock, an encoder which detects the rocking relative angle of the ultrasonic vibrator assembly, an origin detection means which detects the rocking origin of the ultrasonic vibrator assembly, and the rocking origin return means of the ultrasonic vibrator, the rocking relative angle signal of the encoder is a different signal train with using the rocking origin as the border. This signal train can form a small slit 22 and a large slit 23 in the slit plate 21 of the encoder with using the rocking origin as the border and can be composed as the signal train in which an output level differs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasound probe, for example, an ultrasound probe used in an ultrasound diagnostic apparatus that obtains an image in a subject using ultrasound.

  Medical ultrasound capable of constructing an arbitrary tomographic image or stereoscopic image by electronic scanning in the arrangement direction of the ultrasonic transducers and mechanical scanning that moves or swings in a direction orthogonal to the electronic scanning direction A probe is known.

In such an ultrasonic probe, the position of the mechanical scanning is accurately detected by using the origin detecting means and the encoder that operates in synchronization with the mechanical scanning difference. FIG. 8 shows a detailed internal view of a conventional encoder. A slit plate 31 that rotates around the encoder rotation shaft 30 is formed with a plurality of slits 32 concentrically with the encoder rotation shaft 30 at equal intervals in the circumferential direction. The pair of light emitters 33 and light receivers 34 are arranged on both sides of the slit plate on substantially the same radius as the slits 32, detect the slits 32, and generate an oscillation relative angle signal that is a regular pulse train. In this way, the position of mechanical scanning can be accurately detected by the encoder (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 3-184532 (page 3, right column, lines 40-49, FIG. 3)

  However, in such a conventional ultrasonic probe, a dedicated detection means is provided to detect the side where the ultrasonic transducer is located with respect to the oscillation origin when the power is turned on or when the mechanical scanning is stepped out. There was a need. For this purpose, a dedicated part is required, and a space for arranging the part must be secured. Therefore, there are problems that the part cost and the man-hour are increased, and it is difficult to downsize the apparatus.

  The present invention has been made to solve such a problem, and has a configuration that is inexpensive and can be downsized without increasing the number of parts. An object of the present invention is to provide an ultrasonic probe capable of returning to the oscillation origin.

  The ultrasonic probe according to the present invention includes an ultrasonic transducer assembly in which a plurality of ultrasonic transducers that transmit and receive ultrasonic waves are arranged, a driver that swings the ultrasonic transducer assembly, and the ultrasonic vibrations. An encoder that detects a swing relative angle of the child assembly, an origin detection means that detects a swing origin of the ultrasonic transducer assembly, and a swing origin return means of the ultrasonic vibrator, The signal train generated when the swing relative angle is detected is configured to be a different signal train with the swing origin as a boundary.

  With this configuration, it is possible to reduce the cost and reduce the size without increasing the number of parts, and to detect the side where the ultrasonic transducer is located with respect to the oscillation origin and return to the oscillation origin at high speed.

  Further, the ultrasonic probe of the present invention is configured such that the output level of the swing relative angle signal of the encoder is a different signal sequence from the swing origin.

  With this configuration, it is possible to detect the side where the ultrasonic assembly is located with respect to the oscillation origin with a simple configuration that only compares the output levels.

  The ultrasonic probe according to the present invention is configured such that the signal interval of the swing relative angle signal of the encoder is different from the swing origin.

  With this configuration, the output of the light emitter and the sensitivity of the light receiver can be easily managed, and therefore the selectivity of the parts is wide, and therefore, the side where the ultrasonic assembly is located with respect to the oscillation origin can be detected with an inexpensive part.

  In addition, the ultrasonic probe of the present invention is configured to use a signal sequence generated when the oscillation origin of the ultrasonic transducer assembly detects the oscillation relative angle of the encoder.

  With this configuration, it is not necessary to provide the origin detection means independently, and hence the swing origin detection can be realized at a low cost with a small number of parts.

  As described above, according to the present invention, the signal train generated when detecting the swing relative angle of the encoder is configured to be a different signal train with the swing origin as a boundary, so without increasing the number of parts. It is possible to provide an ultrasonic probe capable of detecting the side where the ultrasonic transducer is located with respect to the oscillation origin and capable of returning to the oscillation origin at a high speed with a configuration that can be reduced in size at low cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
1 to 4 are views showing a first embodiment of an ultrasonic probe according to the present invention.

  First, the configuration will be described. In FIG. 1, an ultrasonic probe 11 includes an ultrasonic transducer assembly 12 in which a plurality of ultrasonic transducers (not shown) are arranged, and the ultrasonic transducer assembly 12 includes an ultrasonic transducer assembly 12. A lens that mechanically determines the focal point, a back cushioning material that suppresses transmission of ultrasonic waves to the back side in the direction in which ultrasonic waves are transmitted and received, a matching layer that matches acoustic impedance, and an ultrasonic transducer that transmits and receives electrical signals The connection part for this is built in, and these members are integrally assembled with the ultrasonic transducer | vibrator (all are not shown).

  The oscillating shaft 13 is integrally coupled to inner peripheral portions at both ends in the longitudinal direction of the curved surface corresponding to the strings of the ultrasonic transducer assembly 12 having a convex shape, and the oscillating shaft 13 is oscillated by a support (not shown). It is supported freely. A first pulley 14 is fixed to the swing shaft 13.

  A driving body 15 is provided below the first pulley 14. A second pulley 16 is fixed to an output shaft 15 a of the driving body 15, and the first pulley 14 and the second pulley 16 are connected to each other. A flexible belt 17 as a transmission member is stretched over, and the belt 17 is in sliding contact with the first pulley 14 and the second pulley 16 with appropriate tension. The transmission member is not limited to the belt 17 and may be a wire or the like. Reference numeral 18 denotes an origin detection means. The magnet 18a is fixed to the ultrasonic transducer assembly 12 and swings integrally with the ultrasonic assembly 12. The Hall element 18b is fixed to a housing (not shown) and the magnet 18a comes close to it. The position at the time can be detected. The encoder 19 is configured integrally with the drive body 15 and rotates in synchronization with the rotation of the drive body 15 to generate a swing relative angle signal.

  The ultrasonic probe 11 having such a configuration moves the driving body 15 forward and backward while referring to the swing relative angle signal generated by the encoder 19 based on the swing origin detected by the swing origin detection means 18. As a result, the power is transmitted in the order of the second pulley 16, the belt 17 and the first pulley 14, and the ultrasonic transducer assembly 12 swings around the swing shaft 13.

  Therefore, the electronic scanning using the plurality of ultrasonic transducers constituting the ultrasonic transducer assembly 12 and the mechanical scanning by the oscillation of the ultrasonic transducer assembly 12 around the oscillation shaft 13 are performed. Any tomographic image or stereoscopic image can be constructed.

  FIG. 2 is an internal detail view of the encoder 19 shown in FIG. The encoder rotation shaft 20 is connected to a drive body output shaft 15a (shown in FIG. 1), and the slit plate 21 is fixed to the encoder coater shaft 20. In the slit plate 21, a small slit 22 having a small opening and a large slit 23 having a large opening are formed on the substantially same radius centered on the encoder coater shaft 21 at equal intervals, and a pair of light emitters 24 and light receivers 25 are slit. The small slit 22 and the large slit 23 are disposed on substantially the same radius with the plate 21 interposed therebetween.

  When the drive body 15 shown in FIG. 1 rotates, the encoder rotating shaft 20 and the slit plate 21 rotate, and the small slit 22 and the large slit 23 pass between the light emitter 24 and the light receiver 25. Here, the opening areas of the small slit 22 and the large slit 23 are set so that the amount of light received by the photoreceptor 25 is different.

  FIG. 3 shows the relationship between the swing relative angle signal (middle stage) and the slit (lower stage) generated by the encoder 19 (shown in FIG. 1) when the driving body 15 (shown in FIG. 1) is rotating. Here, the upper stage is the swing origin signal generated from the origin detection means 18 of FIG. 1, and the relative position with respect to the swing relative angle signal is between the ultrasonic transducer assembly 12 and the drive body swing shaft 15a shown in FIG. Adjust the position. For example, the relative position of the swing origin signal and the swing relative angle signal can be adjusted by adjusting and fixing the position between the first pulley 14 and the swing shaft 13 shown in FIG.

  In the present embodiment, the swing origin detecting means 18 is adjusted so as to generate the swing origin signal when the boundary O between the small slit 22 row and the large slit 23 row is interposed between the light emitter 24 and the light receiver 25. (State shown in FIG. 3b). When the slit plate 21 rotates from this state and the position of + A where the small slit 22 of the slit plate 21 is formed as shown in FIG. 3A is located between the light emitter 24 and the light receiver 25, the amount of received light is small. Oscillating relative angle signal with a low output level is generated.

  On the other hand, as shown in FIG. 3c, when the position of -A where the large slit 23 of the slit plate 21 is formed is located between the light emitter 24 and the light receiver 25, the amount of received light is increased compared to the case of the small slit 22. The output level of the swing relative angle signal increases. Here, since both the large slit 23 and the small slit 22 are formed at equal intervals, the signal period is uniform. In this way, it is possible to generate an oscillation relative angle signal sequence having different output levels and having a uniform cycle with the oscillation origin signal as a boundary.

  FIG. 4 is a block diagram relating to the swing origin return means, and the swing origin return means will be described with reference to FIG. First, the drive control circuit starts monitoring the level of the swing relative angle signal, and then generates a small angle rotation signal to rotate the driver by a small angle. Here, the minute angle to be rotated may be an angle corresponding to that the encoder can output one pulse of the swing relative angle signal. For example, if the encoder is rotated in a required time of 10 ms to rotate one pulse, it can be completed in a required time of 10 ms to 20 ms to obtain an output of 1 to 2 pulses.

  The drive circuit checks the level of the swing relative angle signal generated by the encoder and determines the side on which the ultrasonic transducer assembly is located with respect to the swing origin. Here, when a plurality of pulse trains are generated, the level of the last generated pulse may be inspected. Based on this result, the drive control circuit determines the rotation direction and generates a rotation signal for the driver. The driving body rotates based on the rotation signal, the ultrasonic transducer assembly 12 shown in FIG. 1 also rotates in synchronization with the driving body 15, and the swing origin detecting means 18 generates a swing origin signal at the swing origin position. The drive control circuit stops the drive body after detecting the swing origin signal. In this way, the swing origin return is completed.

  In this example, a transmission type photo sensor and slit plate are used to generate the swing relative angle signal of the encoder. However, a reflection type photo sensor or a magnetic field such as MR or Hall element is used. A detection sensor may be used.

  In the present embodiment, an encoder having one phase has been described, but an encoder having a plurality of phases may be used. For example, in a two-phase encoder, the same effect can be obtained even if the output level of the A phase or the B phase is different from the origin.

  As described above, according to the first embodiment of the present invention, the swing relative angle signal generated when detecting the swing relative angle of the encoder is configured to generate different signal sequences with the swing origin as a boundary. Therefore, the side where the ultrasonic transducer assembly is located with respect to the oscillation origin can be detected only by the oscillation relative angle signal, and therefore it is possible to reduce the size and size without increasing the number of parts. The side where the ultrasonic transducer is located with respect to the oscillation origin can be detected and the oscillation origin can be returned at high speed.

  In addition, by configuring the swing relative angle signal so that the output level is different from the swing origin, it is possible to detect the side where the ultrasonic assembly is located with respect to the swing origin with a simple configuration that only compares the output levels. Can do.

(Second Embodiment)
Next, a second embodiment will be described. FIG. 5 shows the relationship between the swing relative angle signal (middle stage) and the slit (lower stage) in the second embodiment. Further, the upper stage is a swing origin signal, which is configured to be adjusted in the same manner as in the first embodiment. In this embodiment, adjustment is made so that the oscillation origin signal is generated in the state of FIG. In FIG. 5b, slits are formed on the left side of the slit plate 21 at θ / 2 intervals, and slits are formed on the right side so that the slit intervals repeat α · θ and (1-α) · θ. (Α <1, α ≠ 0.5). FIG. 5a and FIG. 5c show the state rotated from FIG. 5b in the direction of the arrow. Corresponding to each state, the oscillation relative angle signal generates a pulse having a T / 2 interval in the state of FIG. 5a, and a pulse repeating α · T and (1-α) · T intervals in the state of FIG. 5c. (See middle row).

  The time T used for the pulse interval here corresponds to the angle θ used for the slit forming interval. Since the oscillation relative angle signal generated in this way has different signal intervals with the oscillation origin as a boundary, the side where the ultrasonic transducer assembly is located can be determined by monitoring the pulse interval.

  Next, FIG. 6 shows the relationship between the swing relative angle signal (upper stage) and the slit (lower stage) when a two-phase encoder is used in the second embodiment. Here, the slit is drawn so that the circumferential direction is a horizontal straight line. The slit A phase is formed at intervals of d, and the slit B phase is offset by d / 4 on the right side of the origin and β · d offset on the left side (β <1, β ≠ 1/4). The edges of the output waveforms (middle stage) of the encoder A phase and B phase generated from the slits formed in this way are used as swing relative angle signals (upper stage). The signal relative to the oscillation relative angle signal generated in this way is different in the interval between the oscillation origins. Therefore, the position where the ultrasonic transducer assembly is located can be determined by monitoring the pulse interval.

  As described above, according to the second embodiment, the encoder swing relative angle signal is configured to be different from each other with the swing origin as a boundary. It is easy to manage the output of the light emitter and the sensitivity of the photoreceptor without being involved in the detection of the side where the assembly is located. Therefore, the selectivity of the parts is wide, and the ultrasonic vibrator assembly is positioned with respect to the oscillation origin with inexpensive parts. The side can be detected.

  Note that the origin detection means and the origin return means of the second embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

(Third embodiment)
Next, a third embodiment will be described. In this embodiment, the swing origin is defined based on the signal sequence generated when detecting the swing relative angle of the encoder. Here, the case where the output level of the signal sequence differs from the swing origin is the boundary. explain.

  FIG. 7 shows an example in which the edge of the pulse having the higher signal level is set as the oscillation origin at the boundary between the signal trains having different output levels. The origin return means when the swing origin is determined in this way will be described below. Sequence 1 shown in the upper part of FIG. 7 is a case where the swing relative angle signal is a low output level at the start of the swing origin return, and sequence 2 shown in the lower stage has a high swing relative angle signal at the start of the swing origin return. In this case, the slit plate is fixed and the light emitter and the light receiver are relatively moved in the direction indicated by the arrows.

  In sequence 1, an edge that rotates in one direction from left to right in the figure and switches from a low output level to a high output level is detected. In sequence 2, the rotation direction is changed after switching from the high output level to the low output level pulse once past the oscillation origin. After that, as in the sequence 1, an edge that rotates in one direction and switches from a low output level to a high output level is detected.

  In this manner, the edge of the pulse with the higher signal level can be set as the oscillation origin at the boundary portion of the signal sequence where the output level of the oscillation relative angle signal is different. Here, it is also possible to set the edge of the low output pulse as the oscillation origin, or to set the output pattern difference switching portion as the oscillation origin with an oscillation relative angle signal with a different output pattern.

  As described above, according to the third embodiment of the present invention, the oscillating origin of the ultrasonic transducer assembly is defined from the signal sequence generated when detecting the oscillating relative angle of the encoder. Therefore, it is not necessary to provide the swing origin detecting means alone, and hence the swing origin detection can be realized at a low cost with a small number of parts.

  As described above, the ultrasonic probe according to the present invention has an effect that the oscillation origin position of the ultrasonic transducer assembly can be easily detected and the oscillation origin can be returned at high speed with an inexpensive configuration. It is useful as an ultrasonic probe used in an ultrasonic diagnostic apparatus for obtaining an image in a subject using

1 is an external perspective view of an ultrasonic probe according to the first embodiment of the present invention. Detailed view of the inside of the encoder in the first embodiment of the present invention The figure which shows the relationship between the rocking | fluctuation relative angle signal and slit in the 1st Embodiment of this invention. The block diagram in connection with the rocking | fluctuation origin return means in the 1st Embodiment of this invention The figure which shows the relationship between the rocking | fluctuation relative angle signal and slit in the 2nd Embodiment of this invention. The figure which shows the relationship between the rocking | fluctuation relative angle signal and slit of a two-phase encoder in the 2nd Embodiment of this invention. The figure explaining the rocking | fluctuation origin of the ultrasonic probe in the 3rd Embodiment of this invention Detailed view of conventional ultrasonic probe encoder

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Ultrasonic probe 12 Ultrasonic transducer assembly 13 Oscillation shaft 14 1st pulley 15 Drive body 15a Drive body output shaft 16 2nd pulley 17 Belt (power transmission member)
18 Oscillation origin detection means 18a Magnet 18b Hall element 19 Encoder 20 Encoder rotation shaft 21 Slit plate 22 Small slit 23 Large slit 24 Light emitter 25 Light receiver 30 Encoder rotary shaft 31 Slit plate 32 Slit 33 Light emitter 34 Light receiver

Claims (4)

An ultrasonic transducer assembly in which a plurality of ultrasonic transducers for transmitting and receiving ultrasonic waves are arranged;
A driver for swinging the ultrasonic transducer assembly;
An encoder for detecting a swing relative angle of the ultrasonic transducer assembly;
Origin detection means for detecting the oscillation origin of the ultrasonic transducer assembly;
In the ultrasonic probe having the swing origin return means of the ultrasonic vibrator,
2. The ultrasonic probe according to claim 1, wherein a signal sequence generated when the encoder detects the swing relative angle is a different signal sequence with the swing origin as a boundary. The ultrasonic probe according to claim 1, wherein an output level in a signal sequence generated when detecting a swing relative angle of the encoder is different from the swing origin. 2. The ultrasonic probe according to claim 1, wherein a signal interval generated when detecting a swing relative angle of the encoder is different with respect to the swing origin. 2. The ultrasonic probe according to claim 1, wherein the oscillation origin of the ultrasonic transducer assembly uses a signal sequence generated when detecting the oscillation relative angle of the encoder.

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