JPH05139A - Ultrasonic probe apparatus - Google Patents

Abstract

PURPOSE:To prevent any image running which may occur in an ultrasonic tomographic image. CONSTITUTION:The thickness of a sheath 22 is made less in a range Lb to be subjected to a constant speed scanning out of the range L where a scanning is made with an ultrasonic vibrator 7 as compared with those of both end parts La thereof. An inversion area is judged from a difference in pattern of a multiple echo received with the ultrasonic vibrator 7. Thus, an image signal alone detected in the range Lb scanned at a constant speed with the ultrasonic vibrator 7 is shown on a TV monitor 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe device which detects multiple echoes from a sheath and displays only an image of a constant velocity scanning region of an ultrasonic beam.

[0002]

2. Description of the Related Art In recent years, an ultrafine ultrasonic probe has been developed in the medical field. This is the outer diameter φ1 ~ 3mm
Incorporate an ultrasonic transducer inside the tip of the front and rear flexible probe, insert this into a target site in the human body, transmit and receive ultrasonic beams from the vicinity of this target site,
It is intended to obtain an ultrasonic tomographic image of this region and use it for diagnosis.

This kind of ultrasonic probe is technically characterized in that it has an extremely fine outer diameter, is flexible, and has a high ultrasonic frequency.

Further, since the ultrasonic probe of this type has a small outer diameter and flexibility, it can be used in a deep part of the body where ultrasonic waves could not reach with a conventional external ultrasonic probe. Even in an organ, the probe can be inserted through the lumen up to the vicinity of this organ to transmit and receive ultrasonic waves to visualize an image. In addition, since ultrasonic waves are transmitted and received from the vicinity of the target site, it is possible to use even high-frequency ultrasonic waves with a low degree of progress, and therefore an ultrasonic tomographic image with extremely high resolution can be obtained. Examples of sites suitable for diagnosis with this ultrasonic probe include the biliary organs, the pancreas, and blood vessels.

The scanning method of the ultrasonic probe includes an electronic scanning method and a mechanical scanning method, and the scanning method of the ultrasonic beam can be classified into a digital method and a linear method.

FIG. 17A shows a radial type ultrasonic probe A, and FIG. 17B shows a linear type ultrasonic probe. In the figure, reference numeral 7 is an ultrasonic transducer, and 6 is a sheath.

An ultrasonic probe of mechanical linear scan type is disclosed in, for example, Japanese Patent Laid-Open No. 63-302836.

The structure of a conventional mechanical linear scan type ultrasonic probe apparatus will be described with reference to FIG.

This ultrasonic probe device includes an ultrasonic probe 2 inserted into a human body 1, a drive unit 3 for causing the ultrasonic probe 2 to scan an ultrasonic beam, and an ultrasonic wave for constructing an image signal from a received signal. The observation means 4 and the television monitor 5 for displaying an image.

In the ultrasonic probe 2, 6 is a flexible long sheath, and an ultrasonic transducer 7 is reciprocally housed inside the sheath 6 near the tip thereof. The flexible shaft 8 in the sheath 6 is the drive unit 3
The reciprocating motion generated in (1) is transmitted to the ultrasonic vibrator 7, and the ultrasonic vibrator 7 is reciprocated to linearly scan the ultrasonic beam.

In the drive unit 3, the rotary motion of the motor 9 is converted into reciprocating motion by the conversion mechanism 10, and this is transmitted to the flexible shaft 8. The encoder 11 detects the rotational angular displacement of the motor 9, and based on the detection result, the rotation direction reversal control, the motor rotation control, and the correction of the disturbance of the image 5a caused by the rotation unevenness of the motor 9 are performed. To do.

At the time of diagnosis, the ultrasonic probe 2 is inserted into the target site 12 (for example, the common bile duct) in the human body 1. Then, when the ultrasonic oscillator 7 is reciprocated by the drive unit 3, the ultrasonic beam transmitted and received by the ultrasonic oscillator 7 is linearly scanned, and a reception signal is obtained. This received signal is transmitted to the ultrasonic observation means 4 and converted into an image signal.

Then, this image signal is sent to the television monitor 8 and, as shown in FIG. 20 (a), an ultrasonic tomographic image of the portion scanned with the ultrasonic beam is drawn.

[0014]

FIG. 19 shows the reciprocating motion generated by the drive unit 3 and the reciprocating motion of the ultrasonic transducer 7 reciprocating via the flexible shaft 8 in time series. It is a thing.

The flexible shaft 8 inevitably expands and contracts, and contracts in the steps (a) to (c) in which the driving unit 3 pushes the ultrasonic vibrator 7, and the ultrasonic vibrator 7 is compressed.
It extends during the steps (e) to (g) of pulling.

Therefore, in the strokes (d) and (h) in which the pushing / pulling is reversed, the ultrasonic transducer 7 is momentarily stopped despite the movement of the driving section 3.

However, since the ultrasonic observation means 4 constructs an image signal in synchronization with the rotational displacement of the motor 9 of the drive unit 3 by the signal of the encoder 11, the ultrasonic tomographic image displayed on the monitor 5 is displayed. Is a portion where the ultrasonic transducer 7 stops, that is, as shown in FIG.
Image deletion occurs at both ends of a.

As described above, the conventional ultrasonic probe apparatus has a problem in that a faithful ultrasonic tomographic image cannot be obtained, which seriously hinders diagnosis.

As a countermeasure against this, the displacement of the ultrasonic transducer 7 can be detected directly at the tip of the ultrasonic probe 2, but an encoder can be mounted inside the ultrasonic probe 2 having a small diameter. To make it small enough,
Technically impossible.

Further, when sending the image signal from the ultrasonic observing means 4 to the television monitor 5, a means of cutting and sending the signals at both ends of the image 5a may be considered, but the position of the image content in the forward and backward scan paths. 21 (a),
As shown in (b), there is a problem that the image 5a appears to sway left and right as the ultrasonic transducer 7 reciprocates.

As described above, the conventional technique has a problem that the image deletion at both ends of the image 5a cannot be effectively removed, and the inconvenience in diagnosis cannot be solved.

The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic probe apparatus in which image deletion is eliminated by a simple and effective method.

[0023]

The present invention is directed to an ultrasonic transducer for transmitting and receiving an ultrasonic beam for scanning, an ultrasonic probe having a sheath for movably accommodating the ultrasonic transducer, and the above ultrasonic wave. In an ultrasonic probe device including an ultrasonic wave observation means for converting a received wave of a transducer into an image signal and an image projection means for displaying an ultrasonic tomographic image based on the image signal, the ultrasonic beam of the sheath is scanned. The range in which scanning is performed at a constant speed out of the range described above has a configuration in which the form of multiple echo is different from that of the other portions.

[0024]

In the above construction, the range of constant velocity scanning of the ultrasonic beam scanning range of the sheath is different from that of the other portions in the form of multiple echo. By detecting, it is possible to remove the flow at both ends of the image that occurs when the ultrasonic transducer reverses forward / backward.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of the present invention,
1 is an overall schematic view of an ultrasonic probe apparatus, FIG. 2 is a vertical cross-sectional view of the tip of the ultrasonic probe, FIG. 3 is a vertical cross-sectional view showing the operation of the ultrasonic probe in time series, and FIG. It is a diagram which shows the change of the multiple echo detected by the observation means.

In the figure, a mechanical linear scan type ultrasonic probe apparatus is shown.

(Structure) Reference numeral 21 in the drawing is an ultrasonic probe, which constitutes the ultrasonic probe 21 and in which the proximal end of a flexible elongated sheath 22 is connected to the drive unit 3.
In addition, a housing 7a for fixedly mounting the ultrasonic transducer 7 is housed at the distal end of the sheath 22 so as to be reciprocally movable along the sheath, and the housing 7a is provided with the reciprocating mechanism ( For example, as shown in FIG. 18, it is connected to a motor 9 and a conversion mechanism 10 that converts the rotational movement of the motor 9 into a reciprocating movement.
The ultrasonic transducer 7 reciprocates at the tip of the sheath 22 and scans the ultrasonic beam in a region of the range L. Both ends of the scanning range L of the inner surface 22a of the sheath 22 are scanned. The inner surface 22b of the range (constant speed scanning range) Lb excluding La is set to a position away from the ultrasonic transducer 7 (in the figure, only the constant speed scanning range Lb is separated by reducing the wall thickness). Has been done. The outer surface 22c of the sheath 22 has the same diameter.

Further, reference numeral 23 is a multiple echo detecting means,
The echo received by the ultrasonic transducer 7 is detected.

Reference numeral 24 denotes a multi-echo judging means, which measures the interval between the echoes detected by the multi-echo detecting means 23 and judges whether the scanning direction of the ultrasonic transducer 7 is in the forward / backward inversion region.

Reference numeral 25 is a control means, when the multi-echo determination means 24 determines that the ultrasonic transducer 7 is scanning a region other than the forward / backward inversion region, that is, the constant speed scanning range Lb. Only, the received signal is sent to the ultrasonic observation means 4.

Reference numeral 5 is a television monitor which is an example of a projection means.

(Operation) Next, the operation of the embodiment having the above construction will be described.

When the ultrasonic transducer 7 is in a region near the end of the scanning range L in which the scanning direction is reversed as shown in FIG. 3D, the ultrasonic transducer 7 of the ultrasonic transducer 7 as shown in FIG. After a lapse of time t1 from the output pulse α1, the inner surface 22 of the sheath 22 is
The echo α2 from the a is received, and after the elapsed time t2, the echo α3 from the outer surface 22c of the sheath 22 is received. Therefore, the time difference between the echoes α2 and α3 is t3.

On the other hand, the ultrasonic transducer 7 is shown in FIG.
When scanning at a constant speed as shown in (a) and (f),
As shown in FIG. 4 (b), the echo α2 from the inner surface 22b of the sheath 22 is received after the elapsed time t1 ', and the outer surface 22C is received.
It is assumed that the echo .alpha.3 from .alpha. Is received after the elapsed time t2 '.

Constant speed scanning range Lb in the sheath 22
The inner surface 22b of the echoes is located farther from the ultrasonic transducer 7 than the inner surfaces 22a at both ends thereof, that is, the inner surface 22b is closer to the outer surface 22c. It is shorter than the time difference t3 during inversion (t3 '<t3).

Therefore, the time difference between the echoes α2 and α3 detected by the multiple echo detecting means 23 is determined by the multiple echo determining means 24.
When the time difference is t3 ', the constant speed scanning range Lb is determined, and the signal received by the ultrasonic transducer 7 from the control means 25 is transmitted to the ultrasonic observation means 4.

As a result, the image 5a of only the range Lb in which the ultrasonic transducer 7 scans at a constant speed is displayed on the television monitor 5, and the image flow at the time of reversal is cut.

Further, since the position of the ultrasonic transducer 1 is substantially directly detected by the tip portion of the ultrasonic probe 21, the image 5a does not move left and right as it reciprocates.

In this embodiment, the received signal input to the ultrasonic observing means 4 is intermittent, but the entire wiring is not limited to this, and for example, the output signal of the ultrasonic observing means 4 is used. You may make it intermittent.

(Second Embodiment) FIGS. 5 and 6 show a second embodiment of the present invention. FIG. 5 is a sectional view corresponding to FIG. 2, and FIG. 6 is a diagram corresponding to FIG. 4 (b). is there.

In this embodiment, the inner surface 22a of the sheath 22 is
Are set to have the same diameter, and a portion 22d of the outer surface 22c corresponding to the constant velocity scanning range Lb is set to a position (the wall thickness is made thin in the figure) close to the inner surface 22a, as shown in FIG. , The time difference t3 ″ between the echo α2 from the inner surface 22a of the sheath 22 and the echo α3 from the outer surface 22d.
, The echo α2 s from the inner surface 22a detected at both ends La
Time difference t3 from the echo α3 from the outer surface 22c (Fig. 4)
(See (a)). Therefore, the image signal may be transmitted when the time difference t3 ″ is detected.

According to this embodiment, the inner surface 22a of the sheath is
Have the same diameter, the eccentricity of the ultrasonic transducer 7 during scanning becomes extremely small, and the outer surface 22d may be processed, so that molding is facilitated.

In the constant speed scanning range Lb, the echoes α 2,
It is desirable to set the ratio of the inner diameter to the outer diameter of the sheath 22 to a value close to 1: 1 so that other high-order multiple echoes do not intervene between α3.

The shape of the constant velocity scanning range Lb of the sheath 22 is not limited to the above-mentioned embodiments, but the sheath 2
The shape of the echo from 2 may be different from that of the other portions.

(Third Embodiment) FIG. 7 is a longitudinal sectional view corresponding to FIG. 2 according to a third embodiment of the present invention.

In this embodiment, the filling material 31 is applied to the outer surface 22d of the constant velocity scanning range Lb of the sheath 22 of the second embodiment described above.
And the outer surface of the sheath 22 is flattened, which facilitates insertion of the ultrasonic probe 21.

Since the filling material 31 is made of a material having an acoustic impedance different from that of the sheath 22, the echo α3 on the outer surface 22d of the sheath 22 can be detected in the same manner as in the second embodiment.

(Fourth Embodiment) FIGS. 8 to 11 show a fourth embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the tip of an ultrasonic probe, and FIG. 9 is a control block diagram of the ultrasonic probe apparatus. 10 is a waveform diagram of multiple echoes, and FIG. 11 is a waveform diagram of each output in the control block.

(Structure) Mechanical Scanning Ultrasonic Probe 31
A housing 7a in which the ultrasonic transducer 7 is installed is housed inside the distal end side of a hollow elastic sheath 32 (for example, a Teflon tube) inserted into the body cavity.

The housing 7a is connected to a drive unit 3 (see FIG. 9) including a linear drive source (not shown) by a flexible shaft 8 composed of multiple coils wound in at least two different directions.

A signal cable (not shown) for transmitting and receiving a signal to and from the ultrasonic transducer 7 is also connected from the inside of the housing 7a to the drive section 3 through the flexible shaft 8.

The hollow elastic sheath 32 is positioned at two points on its tip end using an ultrasonic impedance strong reflector (for example, aluminum) whose acoustic impedance is remarkably different from that of the sheath material, water, or the ultrasonic medium 33. Ring 34
a and 34b are attached. The flexible shaft 8 is a motor 9 which is a linear drive source in the drive unit 3, and the position of the motor 9 (that is, the ultrasonic transducer 7).
Position) is connected to the encoder 11 for detection,
The motor 9 and the encoder 11 are connected to the drive control circuit 35.

The ultrasonic transducer 7 is connected to the transmission / reception changeover switch 36 by a signal cable (not shown), and the transmission / reception changeover switch 36 is
It is connected to the transmission circuit 37 and the reception signal amplification circuit 38. The transmission circuit 37 and the reception signal amplification circuit 38 are connected to a gate circuit 39, and the gate circuit 39 is connected to the encoder 11 and the drive control circuit 35.

The gate circuit 39 is connected to a DSC (digital scan converter) 4 which is an ultrasonic wave observation means, and the DSC 4 is connected to a monitor 5.

(Operation) Next, the operation of the fourth embodiment having the above construction will be described.

The housing 7a including the ultrasonic transducer 7 is
When the power from the motor 9 is received via the flexible shaft 8, at least this flexible shaft 9
It moves back and forth in the same direction as the extension direction of.

When the housing 7a starts scanning and reaches one of the positioning rings 34a and 34b, the ultrasonic waves emitted from the ultrasonic transducer 7 are almost totally reflected, and the sound pressure level of the received signal is rapidly increased.

FIG. 10 shows the sound pressure level of the received signal at each position inside the sheath 32 of the ultrasonic transducer 7.

When the ultrasonic transducer 7 is located at the position a in FIG. 8, a reflection signal from the sheath 32 and the outside of the sheath 32 is obtained as shown in a of FIG.

When the ultrasonic transducer 7 is located at the position b in FIG. 8, the ultrasonic waves are totally reflected by the positioning ring 34a, and the sound pressure level becomes high as shown in FIG. 10b.

When the ultrasonic transducer 7 is located at the position c in FIG. 8, it becomes a reflection echo from the outside.

When the ultrasonic transducer 7 is located at the position d in FIG. 8, the ultrasonic wave is totally reflected by the positioning ring 34b, and the ultrasonic wave shown in FIG.
The sound pressure level becomes high as indicated by 0 d.

When the ultrasonic transducer 7 is located at the position e in FIG. 8, the reflected signal is the reflected signal from the sheath 32 and the outside of the sheath 32 as in the case at the position a.

In order to display an image of the signal between the positioning rings 34a and 34b from the received signal as described above, FIG.
Each signal is gated as shown in.

As shown in FIG. 11A, the received signal is compared with the reference signal Vth by the comparator in the gate circuit 39 in order to extract only the interval t1 between the positioning rings 34a and 34b. ) Is obtained.

Further, in the gate circuit 39, a logical product of the obtained gate signal and the A-phase signal of the encoder 11 is obtained, and the signal shown in FIG. 11 (d), that is, the trigger signal between the positioning rings 34a and 34b is obtained. obtain. This trigger signal is input as a timing signal for image display of the DSC 4, and as shown in FIG. 11 (e), the positioning ring 34a,
Only the received signal between 34b is displayed as an image.

Further, the gate signals obtained by the positioning rings 34a and 34b are input to the drive control circuit 35 and used as a signal for switching the ultrasonic transducer 7 in the advancing / retreating direction.

The ultrasonic transducer drive pulse is supplied from the transmission circuit 37 to the ultrasonic transducer 7 when the phase A of the encoder 11 rises and falls.

In this embodiment, the reversal of the forward / backward scanning and the reception signal reception are simultaneously controlled by the position detection of the housing 7a which moves in the distal end of the sheath 32, so that the ultrasonic image on the monitor 5 is displaced. Absent. Further, the advance / retreat control of the ultrasonic transducer 37 can be configured by a simple circuit. Furthermore, when used endoscopically, the scanning width can be visually confirmed, so orientation can be easily applied. Moreover, since the scanning width can be visually confirmed even under fluoroscopy, a more accurate inspection is possible. ..

The present invention is not limited to the mechanical linear scan type ultrasonic probe apparatus, but may be applied to a spiral scanning type ultrasonic probe apparatus for obtaining a three-dimensional image as shown in FIG. The image at the time of inversion of the components can be easily processed. In addition,
Reference numeral 41 is a motor for driving the ultrasonic transducer 7 in the radial direction.

Further, when the ultrasonic probe device of the mechanical sector type as shown in FIG. 13 is adopted, the image at the time of reversal in the swing motion can be easily processed. Reference numeral 51 is a gum to be diagnosed.

The ultrasonic probe device according to the present invention may be applied as shown in FIG. That is,
When the lesioned portion 62 of the lumen 61 is to be cauterized and removed by the laser probe 64 using the endoscope 63, while observing the cross-sectional shape of the affected portion with the ultrasonic probe 21 of the ultrasonic probe apparatus according to the present invention. If cauterization proceeds, the lumen 61
Perforation can be prevented.

Further, as shown in FIG. 15, a white coating film 65 is formed on the surface 22c of the sheath 22 of the ultrasonic probe 21.
If reflective coating such as is applied, damage to the ultrasonic probe 21 due to scattered light of the laser can be prevented. Alternatively, since the portion that may be damaged by the laser is only the ultrasonic oscillator 7, the surface of the ultrasonic oscillator 7 may be provided with a reflective coating such as a metal thin film.

Further, when the ultrasonic probe device according to the present invention is applied to a blood vessel, the ultrasonic probe 21 needs to be strictly sterilized. Normally, the equipment used for the circulatory system is sealed in a disposable pack and sterilized and used only once. However, if a long object such as the ultrasonic probe 21 is stored in the disposable pack as it is, Inconvenient to handle. Therefore, as shown in FIG. 16, it is advisable to store the ultrasonic probe 21 in the disposable pack 71 with a tape measure and to pull it out from the disposable pack 71 at the time of use.

In the figure, reference numeral 71 is an external connection connector.

[0077]

As described above, according to the present invention,
The range where the ultrasonic beam of the sheath of the ultrasonic probe is scanned at a constant speed is configured so that the multi-echo mode is different from that of the other parts. Since the image signal is displayed only when the forward / backward reversal is completed and scanning is performed at a constant speed, the image deletion can be avoided.

Further, since it is equivalent to directly detecting the displacement of the ultrasonic transducer by the ultrasonic probe, the problem that the image of the projection means moves left and right does not occur, and the medical usefulness is impaired. The effect is that

[Brief description of drawings]

1 to 4 show a first embodiment of the present invention, and FIG. 1 is an overall schematic view of an ultrasonic probe device.

FIG. 2 is a vertical sectional view of the tip of the ultrasonic probe.

FIG. 3 is a longitudinal sectional view showing the operation of the ultrasonic probe in time series.

FIG. 4 is a diagram showing changes in multiple echoes detected by ultrasonic observation means.

5 and 6 show a second embodiment of the present invention, and FIG.
Is a vertical sectional view corresponding to FIG.

FIG. 6 is a diagram corresponding to FIG. 4 (b).

FIG. 7 is a vertical sectional view corresponding to FIG. 2 according to a third embodiment of the present invention.

8 to 11 show a fourth embodiment of the present invention, and FIG. 8 is a longitudinal sectional view of the tip of the ultrasonic probe.

FIG. 9 is a control block diagram of the ultrasonic probe device.

FIG. 10: Waveform diagram of multiple echo

FIG. 11 is an output waveform diagram in the control block.

FIG. 12 is a schematic view of a main part of an ultrasonic probe apparatus according to another embodiment.

FIG. 13 is a schematic view of a main part of an ultrasonic probe apparatus according to another aspect.

FIG. 14 is a schematic view of an embodiment in which the ultrasonic probe according to the present invention is used in combination with a laser probe for cauterization.

15 is a vertical cross-sectional view of the tip portion of the ultrasonic probe in FIG.

FIG. 16 is a perspective view of an essential part of an ultrasonic probe device according to another embodiment.

FIG. 17 and subsequent drawings show a conventional example, and FIG. 17 is an explanatory diagram showing divisions by the scanning method of the ultrasonic probe.

FIG. 18 is an overall schematic view of an ultrasonic probe device.

FIG. 19 is an explanatory diagram showing the operation of the ultrasonic probe in time series.

20A is an explanatory diagram showing an ideal ultrasonic tomographic image, and FIG. 20B is an explanatory diagram showing an ultrasonic tomographic image in which image deletion occurs.

FIG. 21 is an explanatory diagram showing a state in which an ultrasonic tomographic image moves left and right.

[Explanation of symbols]

 4 ... Ultrasonic observation means 5 ... Projection means 7 ... Ultrasonic transducer 21 ... Ultrasonic probe 22 ... Sheath L ... Scan range Lb ... Constant velocity scan range

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Ishimura 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. An ultrasonic transducer that transmits and receives an ultrasonic beam for scanning, an ultrasonic probe having a sheath that movably accommodates the ultrasonic transducer, and the ultrasonic vibration. In an ultrasonic probe device including an ultrasonic wave observation means for converting a received wave of a child into an image signal and an image projection means for displaying an ultrasonic tomographic image based on the image signal, the ultrasonic beam of the sheath is scanned. An ultrasonic probe device characterized in that a constant-speed scanning range of the range is different from that of the other part in the form of multiple echo.