JPS63262144A - Ultrasonic vibrator driving apparatus - 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] [Industrial Application Field] The present invention is an ultrasonic device suitable for driving and controlling an ultrasonic transducer installed in, for example, an ultrasonic endoscope and provided so as to be able to rotate and scan. The present invention relates to a vibrator drive device.

[Conventional technology]

Ultrasonic diagnosis is performed by processing signals while controlling the rotation of an ultrasound transducer attached to the tip of an internally inserted part that is inserted into a body cavity such as a human body using a drive mechanism installed outside the body. Ultrasonic endoscopes using the same technology are known, for example, as disclosed in Japanese Unexamined Patent Publication No. 190552/1983.

FIG. 3 is a simplified view of an ultrasound endoscope of the same type as that disclosed in the above-mentioned known example.

A is an internally inserted part, and B is an externally installed part.

An ultrasonic transducer 1 is rotatably held at the distal end of the body insertion part A by a bearing 2. As shown in FIG. And this ultrasonic vibrator 1
The tip of the flexible shaft 3 is coupled to the .

The flexible shaft 3 is held in a flexible outer cylinder 5 via liquid paraffin 4, and its base end is led to an extracorporeal installation part B.

Inside the extracorporeal installation part B, there are a motor 6 as a drive source, a gear box 7 that reduces the rotation speed of this motor 6, a shaft body 8a that transmits the rotation reduced by this gear box 7 to the flexible shaft 3, and It includes an output shaft 8 made of a bearing 8b and a potentiometer 9 attached to the motor 6.

[Problem that the invention seeks to solve]

The conventional ultrasonic endoscope having the above configuration has the following problems. When a subject swallows the body insertion part A of an endoscope, it goes without saying that the thinner the body insertion part A is, the easier it is to swallow. However, if the flexible shaft 3 is made thinner in order to make the body insertion part A thinner, the flexible shaft 3 is likely to be twisted, and the rotation of the motor 6 will not be accurately transmitted to the ultrasonic transducer 1.

That is, when the above-mentioned twist occurs, the rotation of the ultrasonic transducer 1 is delayed by the amount of the twist, and when the twist reaches a certain amount,
This time, a problem arises in that the rotation speed is faster than the normal rotation speed. As a result, the "time-angle" characteristic representing the rotational scanning characteristic pulsates as shown by the solid line in FIG. Moreover, variations occur in the characteristics for each scanning period Tl, T2 and so on for each rotation. For this reason, as shown by the solid line M and the broken line N in FIG. 5, a distortion phenomenon occurs in which the obtained diagnostic image becomes smaller or larger, which hinders diagnosis. Also, as is clear from Figure 4, what should normally be a linear change as shown by the broken line becomes a pulsating change characteristic, and since this pulsation occurs irregularly, the starting position of the next rotational scan fluctuates. . As a result, the image position will be displaced. For example Δθ−20°
Some degree of displacement may occur. For this reason, there was a problem in that it was difficult to perform accurate diagnosis.

If the flexible shaft 3 is made thick (and hard) in order to prevent the occurrence of distortion or displacement of the diagnostic image, the following problems will occur. Since the shaft 3 is relatively common, torsional phenomena still occur.Thus, the rotational transmission of the motor 6 is somewhat stabilized, but the scanning characteristic of the ultrasonic transducer 1 is not linear but pulsating. .

Moreover, since the body insertion part A has a large diameter and lacks flexibility, it is not only thick and difficult to swallow, but also tends to have insufficient curvature within the subject's body cavity, making it difficult to operate. becomes bad.

On the other hand, since a DC motor is normally used as the motor 6 that is the drive source, so-called brush noise is generated in the ultrasonic transducer 1.
It will be on the signal line. As a result, the ultrasonic transducer 1
Due to the scanning operation, flickering, so-called "shimofuri phenomenon", occurs on the screen displayed on the cathode ray tube. Although it is possible to remove this phenomenon using a noise removal circuit such as a filter,
Since it is necessary to include a special noise removal circuit, there are problems in that the endoscope as a whole becomes large and complicated, and its reliability decreases.

The present invention has been made based on these circumstances, and its purpose is to create a small-diameter flexible structure between an ultrasonic transducer capable of rotational scanning and an apparatus main body equipped with a drive system and a signal control system. Of course, it is possible to connect with a connection cable that has the characteristics of
It is an object of the present invention to provide an ultrasonic transducer driving device which can obtain extremely good images without causing any distortion or displacement in the obtained diagnostic images, and which has a simple structure and high reliability.

[Means for solving problems]

In order to solve the above-mentioned problems and achieve the object, the present invention takes the following measures. That is, the rotor of the ultrasonic motor is coupled to the ultrasonic vibrator so as to apply a driving force to the ultrasonic vibrator provided so as to be able to rotate and scan, and drive energy can be supplied to the stator of the ultrasonic motor. The power supply path was arranged as follows.

[Effect]

By grooving the above means, the following effects are achieved.

Since the ultrasonic transducer capable of rotational scanning is directly rotationally driven by an ultrasonic motor installed near the ultrasonic transducer, there is no interference between the ultrasonic transducer and the main body of the device, which is equipped with a drive control system and a signal control system. can be connected using a small diameter and flexible connection cable containing only electric wires. Even if the connection cable is twisted, the rotation of the ultrasonic transducer is not affected at all, so that a predetermined driving force can be stably and accurately transmitted to the transducer. Furthermore, since the ultrasonic motor does not generate brush noise or the like, there is no risk of noise interference. As a result, there is no possibility that distortion or displacement will occur in the obtained image, making it possible to obtain an extremely good image. Furthermore, since the number of mechanical components such as a motor and a gear box is reduced, the structure becomes simpler and reliability is improved.

〔Example〕

FIG. 1 is a diagram showing the configuration of an embodiment in which the present invention is applied to a drive system for an ultrasonic transducer of an ultrasonic endoscope. In FIG. 1, reference numeral 10 denotes an ultrasonic transducer attached to the distal end portion of the body insertion section A. As shown in FIG. This ultrasonic transducer 10 is mainly composed of a diaphragm 11 and a damper member 12, and an acoustic medium 13 is filled around the diaphragm 11 and a damper member 12. The rotating shaft 14 attached to one end of the ultrasonic transducer 10 has a bearing portion 20.
It is rotatably supported.

The bearing section 20 is composed of a pair of bearings 21 and 22. A rotation detection piece 23 is attached to the rotating shaft 14 located between the bearings 21 and 22, and a rotation detection piece 23 is mounted on the outer peripheral surface of the rotation detection piece 23 so as to be opposed to it at a predetermined distance. , a rotation start pulse detection sensor 24 is installed.

- An ultrasonic motor 30 is disposed between the bearing section 20 and the ultrasonic vibrator 10.

The ultrasonic motor 30 includes a rotor 31 which is coupled and fixed to one side of the ultrasonic vibrator 10 with a center hole fitted into the rotation shaft 14, and a rotor 31 which is rotatably fitted into the center hole into the rotation shaft 14. The stator 32, which is coupled and fixed to one side of the bearing section 20 in the mated state, is placed in pressure contact with the stator 32, facing each other. The ultrasonic vibrator 1 is located at the center of the opposing surface of the rotor 31 and stator 32 of the ultrasonic motor 30.
Rotary transformer elements 33 and 34 for transmitting 0 transmission/reception signals in a non-contact manner are disposed close to each other and facing each other.

A pair of electrodes and a ground electrode of the stator 32 of the ultrasonic motor 30 are connected to one end of each of power supply paths 41, 42 and 43 wired inside the body insertion part A. Further, the coil of the primary element 34 of the rotary transformer element is connected to one end of a signal transmission path 44 which is also wired inside the body insertion part A. The power supply lines 41, 42 and 43, and the signal transmission line 44 are led to the extracorporeal installation part B.

The extracorporeal installation section B includes a drive control system and a signal control system for the ultrasound transducer 10. The drive control system includes an oscillator 50 that is a drive source, an amplifier 51 that amplifies the oscillation output from the oscillator 50 and sends it out via the power supply path 41, and amplifies the oscillation output from the oscillator 50 by, for example, π/2. A variable phase shifter 53 capable of shifting the phase, and this variable phase shifter 5
The output phase of the oscillator 50 is compared with the current rotational phase of the ultrasonic motor 30 obtained through the power supply path 43 and the amplifier 52 that amplifies the output of 3 and sends it out through the power supply path 42. , and a phase comparator 54 which supplies the difference as a feedback signal to the variable phase shifter 53. The signal control system also includes a transmitter 60 that is a signal source, a signal that sends an output signal of the transmitter 60 via a signal transmission path 44, and a signal that takes out a reflected signal that returns via the signal transmission path 44. a transmitting/receiving means 61 and a preamplifier 6 for amplifying the reflected signal extracted by the signal transmitting/receiving means 61;
2, and a signal output line 63 for sending this preamplifier 62 to a signal processing system.

Note that the bearings 21 and 22 of the bearing section 20 and the rotation detection piece 23
, the surroundings of the detection sensor 24, ultrasonic motor 30, etc.
Covered with liquid paraffin.

Since liquid paraffin has lubricating and insulating properties, no problem will occur even if a motor etc. is immersed in it.

However, the lead wires etc. are molded.

As described above, in this embodiment, the internal insertion part A of the endoscope is
The ultrasonic transducer 10, which is rotatably provided at the tip of the ultrasonic transducer 10, is directly driven by an ultrasonic motor 30 placed near the ultrasonic transducer 10. The flexible shaft 3 for driving becomes completely unnecessary.

Therefore, a connection cable containing only electric wires can be used as the cable for connecting the ultrasonic transducer 10 and the extracorporeal installation part B, which is the device main body, so the diameter of the internal insertion part A can be reduced. You can do this while remaining flexible. Therefore, it becomes easy for the victim to swallow, and it also becomes easier to manipulate inside the body cavity. Furthermore, since the rotational instability of the ultrasonic transducer 1o due to the twisting of the flexible shaft 3 does not occur as in the conventional case, the rotational scanning of the ultrasonic transducer 1o is accurate and stable as shown in FIG. Become. As a result, a stable image can be obtained without the risk of distortion or displacement occurring in the obtained diagnostic image. Further, no brush noise is added to the signal transmission path 44, and no "whitening phenomenon" occurs in the image. Furthermore, mechanical components such as the DC motor 6, gear box 7, and potentiometer 9, which were conventionally necessary, are no longer necessary, so the extracorporeal installation part B, which is the main body of the apparatus, can be downsized.

Note that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, a thin and flexible connection cable is used to connect an ultrasonic transducer capable of rotational scanning and an apparatus main body equipped with a drive control system and a signal control system. Not only can it be connected, but it can also stably and accurately transmit a predetermined driving force to the transducer, and there is no noise interference from the driving source, which causes distortion or displacement in the resulting diagnostic image. Accordingly, it is possible to provide an ultrasonic transducer driving device that can obtain extremely good images without causing problems, and has a simple structure and high reliability.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of one embodiment of the present invention, and FIG. 2 is a diagram showing the rotational scanning characteristics of the ultrasonic transducer of the same embodiment. FIG. 3 is a simplified diagram showing the configuration of a conventional example, FIG. 4 is a diagram showing the rotational scanning characteristics of the ultrasonic transducer of the same example, and FIG. 5 is a diagram showing the state of a diagnostic image in the same example. 10... Ultrasonic vibrator, 11... Vibration plate, 12...
- Damper member, 13... Acoustic medium, 14... Rotating shaft, 20... Bearing part, 21. 22... Bearing, 23.
... Rotation detection piece, 24 ... Rotation start pulse detection sensor, 30 ... Ultrasonic motor, 31 ... Rotor, 3
2... Stator, 33.34... Rotary transformer element, 41.42.43... Power supply line, 44... Signal transmission line, 50... Oscillator, 51.52... Amplifier, 53 ... variable phase shifter, 54 ... phase comparator, 60
. . . transmitter, 61 . . . transmitting and receiving means, 62 . . . preamplifier, 63 . . . signal output line. Applicant's agent Patent attorney Atsushi Tsuboi Figure 5

Claims (1)

[Claims] An ultrasonic transducer provided to be able to rotate and scan, an ultrasonic motor having a rotor coupled to the ultrasonic transducer so as to apply a driving force to the ultrasonic transducer, and a stator of the ultrasonic motor. An ultrasonic transducer driving device characterized by comprising a power supply path wired so as to be able to supply driving energy.