JPH04322642A - Mechanical scan type ultrasonic probe - Google Patents

Abstract

PURPOSE:To eliminate a long cycle of image oscillation on a display screen by setting the number of teeth on the drive and driven sides of a transmission mechanism to an integer ratio. CONSTITUTION:A toothed pulley 3B and a toothed belt 3C are used as mechanism for transmitting a driving force of a motor 1 with an encoder to an ultrasonic vibrator 2. When a number of tooth ratio between the toothed pulley 3B and the toothed belt 3C is set at 1:N(N=integer), the toothed pulley 3B is meshed with the original teeth at a rotation of N and proportionally, one cycle of oscillation of a display image corresponds to the N rotation of the ultrasonic vibrator. As the oscillation cycle of the display image is shorter, the oscillation can not be checked sensorsally and thus, the number of teeth ratio N is preferably smaller.

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 used in medical ultrasonic diagnostic equipment and the like.

0002

2. Description of the Related Art Generally, the power transmission mechanism of a mechanical scanning ultrasonic probe uses a toothed mechanism because it is necessary to reliably transmit the driving force of the driving means. Hereinafter, a conventional mechanical scanning type ultrasound probe will be explained using FIG. 4.

In FIG. 4, 1 is a motor with an encoder fixed to a frame 5, 2 is an ultrasonic transducer for transmitting and receiving ultrasonic waves, and a housing 4 is surrounded by an ultrasonic propagation medium 9 such as butanediol. and is rotatably attached to the frame 5. 13A and 13B are a drive side gear and a driven side gear respectively, 13C and 13D are a toothed pulley and a toothed belt respectively, and by combining these, the driving force of the encoder-equipped motor is transmitted and the ultrasonic vibrator is rotated. . Also, 6 is an oil seal, 8
is a cable that sends and receives various signals to and from the encoder-equipped motor 1 and the ultrasonic probe 2.

In the conventional example mentioned above, the drive side gear 13
The number of teeth between A and driven gear 13B is set to 1:2, and the number of teeth of toothed pulley 13C and toothed belt 13D are 36 and 78, respectively. At this time, if we pay attention to one set of teeth of the toothed pulley 13C and the toothed belt 13D, we can see that the teeth are 36 and 78.
Since the greatest common divisor of is 468, the original teeth will mesh with each other if the toothed pulley 13C rotates 13 times and the toothed belt 13D rotates 6 times.

[0005]

However, in the conventional mechanical scanning type ultrasonic probe described above, if the toothed pulley 13C and the toothed belt 13D have the same tooth profile, no error in transmission of the rotation angle occurs; With pulley 13C and toothed belt 13
Due to the machining accuracy of D and the eccentricity of the rotation center and tooth surface of the toothed pulley 13C, in FIG. This results in long-period shaking that can be visually confirmed during ultrasound diagnosis.

The present invention solves the above-mentioned problems, and provides an excellent mechanical scanning type ultrasound probe that is free from long-period image fluctuations on ultrasound diagnostic images caused by the influence of the power transmission mechanism. The purpose is to

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a system in which the number of teeth of a power transmission mechanism (for example, a gear or a toothed belt) between a rotary drive machine and an ultrasonic vibrator is set at a driving side and a driven side. so that it becomes an integer ratio.

[0008]

[Operation] With the above-described structure, the present invention eliminates long-period image fluctuations on ultrasonic diagnostic images that occur due to the influence of the power transmission mechanism in a mechanical scanning ultrasonic probe.

[0009]

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

FIG. 1 is a sectional view of a mechanical scanning type ultrasonic probe using a toothed belt transmission mechanism showing a first embodiment of the present invention. Components that are the same as those in the conventional example are given the same numbers. In FIG. 1, a toothed pulley 3C and a toothed belt 3D are used as a mechanism for reliably transmitting the power of the encoder-equipped motor 1 to the ultrasonic transducer 2. At this time, the ratio of the number of teeth between the toothed pulley 3C and the toothed belt 3D is set to 1:N (N=integer). When the toothed pulley 3C rotates N times, the toothed belt 3D rotates once and the original teeth mesh with each other. Then,
In proportion to this, one period of vibration of the displayed image is
This corresponds to N rotations of . The smaller the period of vibration of the display image caused by the transmission mechanism, the smaller the vibration is, which cannot be detected visually due to the followability of the monitor or visual sense.

FIG. 2 is a sectional view of a mechanical scanning type ultrasonic probe using a gear transmission mechanism showing a second embodiment of the present invention. In FIG. 2, when the ratio of the number of teeth between the driving gear 3A and the driven gear 3B is set to 1:N (N=integer), as explained using FIG. N rotations constitutes one period, and the smaller the tooth number ratio N, the less it can be visually confirmed. Furthermore, when the ratio of the number of teeth is 1:1, it is easy to establish a correlation between the driving gear 3A and the driven gear 3B. By meshing the maximum part of the driven gear 3B with the driven gear 3B, the vibration of the ultrasonic transducer 2 caused by the eccentricity between the driving gear 3A and the driven gear 3B is also reduced.
Shaking on the displayed image becomes even smaller.

FIG. 3 is a sectional view of a mechanical scanning type ultrasonic probe using a transmission mechanism using gears and a toothed belt, showing a third embodiment of the present invention. In FIG. 3, the ratio of the number of teeth between the drive side gear 3A and the driven side gear 3B, between the toothed pulley 3C and the toothed belt 3D is set to 1:N (N=integer). In this case, the fluctuation of the displayed image corresponds to the periodicity of the rotational position error of the ultrasonic transducer 2, which is the product of the ratio N of the number of teeth of the driven gear 3B and the ratio N of the number of teeth of the toothed belt 3D.

[0013]

Effects of the Invention As explained above, the present invention provides a mechanical scanning ultrasonic probe in which, when the transmission mechanism of the rotary drive machine and the ultrasonic transducer is toothed, the ratio of the number of teeth of a pair is set to an integer. By adjusting the ratio, it is possible to eliminate long-period image fluctuations on ultrasonic diagnostic images that occur due to component precision and assembly precision of power transmission mechanisms such as gears, toothed pulleys, and toothed belts.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of a mechanical scanning ultrasound probe in a first embodiment of the present invention.

FIG. 2 (a) is a front sectional view of a mechanical scanning ultrasound probe according to a second embodiment of the present invention; FIG. 2 (b) is a side sectional view of the same;

FIG. 3 is a front sectional view of a mechanical scanning ultrasound probe according to a third embodiment of the present invention.

[Figure 4] Front sectional view of a conventional mechanical scanning ultrasound probe

[Explanation of symbols]

1 Motor with encoder 2 Ultrasonic transducer 4 Housing 5 Frame 6 Oil seal 7 Case 8 Cable

Claims (5)

[Claims] 1. A rotary drive means, an ultrasonic transducer for transmitting and receiving ultrasonic waves, and a transmission means for transmitting the driving force of the rotation drive means to the ultrasonic transducer, the transmission means having a reduction ratio. A mechanical scanning ultrasonic probe characterized by being an integer. 2. The mechanical scanning ultrasonic probe according to claim 1, wherein the transmission means comprises a toothed pulley and a toothed belt. Claim 3: Claim 1 wherein the transmission means comprises a plurality of gears.
Mechanical scanning ultrasonic probe as described. 4. The mechanical scanning ultrasonic probe according to claim 1, wherein the transmission means comprises a plurality of gears, a toothed pulley, and a toothed belt. 5. The mechanical scanning ultrasonic probe according to claim 1, wherein the rotational drive means is a motor with an encoder.