JP2009090074A - Ultrasonic examination unit or ultrasonic examination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve issues of conventionally proposed immersion type automatic ultrasonic examination apparatus for breast cancer that a special ultrasonic probe with wide view field width is used resulting in difficulty of the ultrasonic probe hardly to be close to the body surface to be brought in parallel with the body surface causing deterioration of image quality, and not only the ultrasonic probe but also the ultrasonic examination apparatus body requires larger scale and higher price. <P>SOLUTION: An ultrasonic probe with narrow view field width is used and shift and tilt functions are newly added to mechanical rotation and vertical movement of conventional probes. By performing feedback control using ultrasonic reflection data, it is enabled for the ultrasonic probe to be close to the body surface and brought in parallel with the body surface. By using a conventional ultrasonic probe with narrow width, costs of the ultrasonic probe and the apparatus body are suppressed to the minimum and the apparatus body is enabled to be used as a general purpose ultrasonic examination apparatus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water immersion ultrasonic inspection unit or an ultrasonic inspection apparatus particularly used for breast cancer screening and the like.

  Currently, in ultrasonic examination, an engineer holds an ultrasonic probe (hereinafter simply referred to as a probe) and collects image data while directly contacting the probe with the body surface. Since ultrasound hardly propagates in the air, a paste is applied to the body surface, and a cross-sectional image of the body is displayed in real time when the probe is applied to the body surface. When using ultrasonography for breast examination, the technician manually moves the probe, records the breast cross-sectional image, records the image data of the part that seems to be abnormal, examines the whole breast cross-section, and records it The doctor will interpret the image afterwards and make a diagnosis. However, in such a method, the test result greatly depends on the skill of the engineer, takes time, and the reproducibility of the data is poor, which is not suitable for the examination. Therefore, an automated apparatus that can automatically collect reproducible data in a short time is required for medical examination. So far, several automated devices for breast cancer screening have been proposed. In these proposals, in order to automatically collect data of the entire cross section of the breast, the direct contact method (for example, refer to Patent Document 1) in which the probe is mechanically rotated while the probe is applied to the body surface, and the probe and the body surface are disclosed. And a water immersion method (for example, refer to Patent Document 2) in which the probe is mechanically moved with warm water interposed therebetween.

  In the direct contact method, since the probe surface is in direct contact with the breast surface, the distance between the probe and the subject is short, and the ultrasonic beam enters the subject almost perpendicularly. As a feature of the ultrasonic device, in order to obtain good image quality, it is preferable to make the distance between the probe and the subject as close as possible and to make the ultrasonic beam enter the body surface as perpendicular as possible, so the direct contact method is excellent in this respect. Yes. However, since the breast is a soft tissue and deforms when the probe is brought into contact with it, the image obtained by simply moving the probe mechanically is not reproducible, and the shape and size of the breast vary greatly between individuals. A portion where the probe and the body surface cannot be contacted easily occurs, which is not sufficient as an automated screening apparatus.

On the other hand, in the water immersion method, since the probe is not brought into contact with the breast surface, the breast is not deformed and an image with good reproducibility is always obtained. However, the surface of the breast is not a flat surface but a curved surface, and the size and shape vary greatly from person to person. Therefore, a conventionally proposed method of moving the probe along a specific trajectory or a probe with a wide field of view It is difficult to make the distance between the probe and the breast surface always the shortest and to make the ultrasonic beam incident perpendicularly to the body surface by the method of rotating it automatically. Further, in order to obtain a good image quality with a probe having a wide field of view, the number of vibrating elements must be increased. For example, the number of vibrating elements of a probe currently used for breast examination by manual scanning is about 192, and the visual field width is about 55 mm. Assuming that the circumference of the breast is approximately circular, the radius is considered to be within 12 cm in the Japanese except for special cases, and a field width of 12 cm is required. In order to capture an image of this width without degrading the image quality, the number of elements must be about 2.2 times 420 elements. Such multi-element and long-axis probes are extremely difficult to manufacture, and the number of cables for transmission and reception and the number of channels in the main circuit must all be increased by 2.2 times. There is a disadvantage that compatibility with other ultrasonic diagnostic apparatuses is lost.
Japanese Patent Application No. 2002-118643 JP-B 62-4989

  As described above, the water immersion method is suitable as an automated screening device that can always collect highly reproducible data without deforming the breast, but for subjects with large individual differences in size and shape, It is difficult to always make the distance between the probe and the breast surface the shortest and make the ultrasound beam perpendicularly incident on the body surface, and when using a probe with a wide field of view, the cost is greatly increased and the general purpose There is a big problem that compatibility with the ultrasonic diagnostic apparatus is lost.

  The present invention is intended to solve such a conventional problem, and can always obtain a reproducible image without deforming the breast. An ultrasonic breast cancer screening device that can always minimize the distance of the laser beam and allow the ultrasonic beam to enter the body surface perpendicularly, minimizes costs, and is compatible with general-purpose ultrasonic diagnostic devices. The purpose is to provide.

  A first means for solving the above problems includes a probe in which transducers are arranged in an array, a rotation mechanism that rotates the probe in a horizontal direction, a vertical movement mechanism that moves the probe up and down, and a diameter of the probe. The apparatus is constituted by a shift mechanism that shifts in the direction, an angle adjustment mechanism that changes the angle of the probe, and a liquid container that stores the probe and the liquid.

  A second problem solving means is to provide a sensor for detecting a distance or an angle in the vertical movement mechanism and the angle adjustment mechanism, and to control the vertical position and angle of the probe.

  The third problem solving means uses ultrasonic reflection information to control the vertical position and angle of the probe so that the distance between the subject and the probe is as close as possible and the ultrasonic beam is incident on the subject as perpendicularly as possible. Is.

  A fourth problem solving means is that the shift positions in the radial direction by the shift mechanism are three or more.

Effects and effects of the invention

  The operation and effect of the first problem solving means is that the distance between the probe and the surface of the breast and the incident angle of the ultrasonic beam can be changed mechanically and freely without deforming the breast. In addition, since the shift mechanism does not require the use of a special probe having a wide field of view, it is possible to use a normal probe having a narrow field width, and thus the cost of the probe and the main body circuit is greatly reduced.

  The operation and effect of the second problem solving means is that the vertical position and angle of the probe can be freely controlled to predetermined values by providing a sensor for detecting the distance or angle in the vertical movement mechanism and the angle adjustment mechanism. And that information can be recorded.

  The action and effect of the third problem solving means is that the relationship between the distance between the body surface and the probe is obtained using the reflection information of the ultrasonic wave, and the distance between the body surface and the probe is always as close as possible and superb by feedback control. The sound beam is incident on the body surface perpendicularly, and a good image is always obtained.

  The action and effect of the fourth problem solving means is to use a probe having a narrow field of view equivalent to that normally used for breast examination by setting the radial shift position by the shift mechanism to three or more positions. It is possible to collect high-quality data of all breasts. By using a probe with a narrow field of view, it is easy to make the ultrasonic beam perpendicularly incident on the subject, even with a linear probe, with the distance between the subject and the probe approaching the curved surface shape of the body surface, Furthermore, it can greatly contribute to the cost reduction of the probe and the main body apparatus and can be compatible with a general-purpose ultrasonic apparatus.

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

FIG. 3 is a system configuration diagram showing the entire ultrasonic inspection apparatus of the present invention. The ultrasonic inspection unit 21 includes a liquid container, a probe, a probe driving mechanism, and the like, and is a unit that transmits and receives ultrasonic pulses to and from a subject, and will be described in detail later.
A portion B surrounded by an alternate long and short dash line in FIG. 3 is an ultrasonic transmission / reception circuit and image generation means for generating a cross-sectional image from the received signal. The pulse voltage generated by the transmission circuit 26 is transmitted to the probe in the ultrasonic inspection unit 21 to generate an ultrasonic pulse. The ultrasonic pulse enters the living body, and the reflected wave is detected by the same probe and supplied to the receiving circuit 22. The reception signal processing circuit 23 processes the signals of the plurality of vibration elements received by the reception circuit and writes them into a digital scan converter (hereinafter referred to as DSC) 24. The DSC 24 constitutes a two-dimensional cross-sectional image using the obtained received signal, and the cross-sectional image is displayed on the monitor 32 via the image synthesis unit 25.

  The mechanism control circuit 28 is a circuit for controlling the rotation and vertical position, probe angle, and shift position of the probe in the ultrasonic inspection unit 21, and the position and angle information detected by the sensor in the probe driving mechanism is the position. The mechanism control circuit 28 sends a control signal to the probe driving mechanism based on the information supplied to the angle detection unit 27. The information of the position / angle detection unit 27 is sent to the additional information unit 29, and the position / angle information of the probe is superimposed on the image by the image synthesis unit 25 and displayed on the monitor 32. The tomographic image and additional information are recorded in the memory and can be read out when necessary. These are all computer-controlled by a CPU (central control unit) 31. In FIG. 3, the signal flow is indicated by a solid line, and the control signal from the computer is indicated by a dotted line.

  A portion C surrounded by a one-dot chain line in FIG. 3 is a monitor 32 for displaying the generated cross-sectional image and an input means 33 for setting photographing conditions and display conditions.

  FIG. 4 shows an example of a cross-sectional view of an ultrasonic inspection unit 21 that is generally considered conventionally. The liquid container is composed of a non-stretchable frame 41, and a probe 44 is provided in the liquid container and filled with hot water 45. On the upper surface of the non-stretchable frame 41, there is a thin film 42 that is stretchable and transmits ultrasonic waves. The probe 44 is generally called a linear array probe, and has a large number of vibration elements 43 on the upper surface for transmitting and receiving ultrasonic waves. At the time of examination, the breast is inserted into the warm water 45 through the membrane 42, an ultrasonic pulse is transmitted from the vibration element 43 to the breast tissue through the membrane 42 and the warm water 45, and the reflected wave from the breast tissue again becomes the warm water 45. The vibration element 43 receives the signal via the film 42. Linear electronic scanning is performed by the large number of vibration elements 43, and a cross-sectional image is obtained in real time.

  On the other hand, the probe 44 is attached to a rotary shaft 47, and the rotary shaft 47 is rotated by a motor 49 to perform mechanical scanning and collect a cross-sectional image in a 360-degree direction. The rotating shaft is supported and sealed by bearings 48a and 48b. Further, there is a shaft 46 at a portion where the probe 44 is coupled to the rotating shaft 47, and the tilt angle of the probe 44 can be changed by a driving mechanism not shown in the drawing. Warm water at about 37 ° C. is supplied from the water supply pipe 50 into the liquid container and drained from the drain groove 51 through the drain pipe 52. There are a water supply valve 53 and a water discharge valve 54 for controlling water supply and drainage. The frame 41 of the liquid container is fixed to the pedestal 55.

  FIG. 1 is a view showing an ultrasonic inspection unit 21 of the present invention. The aquarium 10 is filled with warm water, and the probe 1 is in it. The breast is inserted into the warm water from above the aquarium 10 through a thin film not shown in the figure. The probe 1 is equivalent to the one currently used by an engineer for breast examination by manual scanning, for example, having a frequency of 8 MHz and about 192 vibration elements, and a cross-sectional image of the field of view 5 indicated by a square frame. It can be obtained in real time. The visual field width is about 55 mm, the visual field depth is 60 mm, and the visual field area is about 55 mm × 60 mm.

  The probe 1 is coupled to the arm 2 via the rotating shaft 3, and the arm 2 is fixed to the rotating shaft 8 at the fixed end 4 of the arm, and the probe can be rotated horizontally around the center AA of the rotating shaft 8. Further, by moving the rotary shaft 8 up and down, the probe 1 can be moved up and down while keeping the angle of the arm 2 constant. In order to make the explanation easy to understand, the arm 2 in the figure is drawn with a single thick straight line, but is actually made of a rigid body having a width. The rotation axis 8 for rotating the probe 1 in the horizontal direction and moving it up and down is called a horizontal rotation axis, and the rotation angle thereof is called a horizontal rotation angle. The probe 1 can reciprocate around the rotation shaft 3 to change the angle. Hereinafter, the rotation of the probe 1 around the rotation axis 3 is referred to as a tilt, the rotation axis 3 is referred to as a tilt axis, and the rotation angle is referred to as a tilt angle. The tilt shaft 3 can move along the arm 2 and is called a shift.

  The horizontal rotation shaft 8 and the tilt shaft 3 have a sensor (not shown) for detecting the rotation angle, and the horizontal rotation angle and tilt angle can be accurately controlled by a motor using the angle information of the sensor. The rotation control of the horizontal rotating shaft 8 may be performed by the conventional method shown in FIG. 4, and the tilt angle can be controlled by a motor attached directly to the arm 2 or outside the water tank via a thin wire. The tilt shaft 3 or the arm 2 has a position sensor for detecting the shift position of the probe 1, and the shift position along the arm 2 can be controlled by driving a motor via a wire while detecting the shift position information. is there. Usually, there are three shift positions and the shift interval is 30 to 50 mm. The horizontal rotation shaft 8 also has a sensor for detecting the vertical position, and the vertical position can be accurately controlled by driving the motor while detecting the vertical position information. What is used for general mechanism control, such as an encoder for detecting the horizontal rotation angle, tilt angle, and position, and a servo motor or stepping motor for rotation and movement, may be used.

  With the configuration described above, four pieces of information on the horizontal rotation angle, the vertical position, the shift position along the arm, that is, the rotation radius, and the tilt angle of the probe 1 are transmitted to the position / angle detection unit 27 in FIG. These can be accurately controlled by the circuit 28.

  Next, a method of collecting ultrasonic image data using such a probe rotation / movement mechanism will be described in detail. The position of the first probe when collecting ultrasound image data is the probe 1 drawn by a solid line in FIG. 1 by the shift mechanism, and is set at a position farthest from the horizontal rotation axis 16, that is, on the outer periphery of the breast. Is set so that the surface of the probe 1 is as parallel as possible to the breast surface (body surface), that is, the ultrasonic beam is incident on the body surface perpendicularly. Further, the probe 1 and the body surface are set as close as possible to, for example, 5 mm by moving the horizontal rotation shaft 8 up and down. A method for setting the tilt angle and the vertical position will be described in detail later.

  When data collection is started, the horizontal rotation shaft 8 rotates 360 degrees to the right when viewed from below, and image data of the cross section 5 of the outer peripheral portion of the breast is collected, and the shift position and horizontal rotation angle of the probe 1 are collected in the memory 30 of FIG. It is recorded together with information on the vertical position and tilt angle. While the probe 1 rotates horizontally, the vertical position and tilt angle are controlled from moment to moment so that the distance between the surface of the probe 1 and the body surface is as close as possible and parallel. FIG. 2 is a diagram showing a position rotated 180 degrees in the middle. The shift position and the tilt angle of the arm 2 are constant, but the cross-sectional shape of the breast is not symmetrical. In contrast, the surface of the probe 1 is controlled to be as close and parallel to the body surface as possible. For example, if the data collection time for one cross-sectional image is about 1/50 second, and if one image is collected every 0.5 degree rotation, the time required for one rotation is about 15 seconds, which is 720 sheets. Are collected and recorded in the memory 30.

  When the probe 1 rotates once by the rotation of the horizontal rotation shaft 8, the probe 1 is shifted to the central portion of the arm by the shift mechanism. This is the probe depicted by the dotted line with the shift position in FIG. In this case, the shift distance of the probe is about 40 mm. While shifting to the intermediate position, the probe 1 rotates 360 degrees horizontally in the opposite direction while changing the vertical position and tilt angle. The reason for rotating in the reverse direction is to avoid the cable connected to the probe from getting caught up. The state at the 180 degree horizontal rotation position at this time is shown in FIG. When the probe 1 makes one rotation at the intermediate position, the probe 1 is shifted to a position close to the horizontal rotation axis 8, that is, the nipple. The shift distance at this time is about 50 mm, and this state is a probe drawn by a dotted line with the shift position in FIG. The probe 1 is horizontally rotated again in the opposite direction to that in the intermediate position in the same manner as in the intermediate position. FIG. 2 shows a state at a horizontal rotation angle of 180 degrees at this shift position.

  In this way, by rotating the probe 1 three times (1.5 reciprocations) in the horizontal direction, the distance between the probe and the body surface is always close enough and the ultrasonic beam is incident perpendicularly to the body surface. Image data can be collected over the entire area of the outer peripheral part, the intermediate part, and the part close to the nipple. The shift distance is smaller than the visual field width, and as can be seen from FIG. 1 and FIG. The collected image data can be displayed and interpreted as it is, but using a recent digital camera software, the outer peripheral part, the middle part, and the part near the nipple of the same horizontal rotation angle are connected to form a single image. It is also easy to display as. In the description so far, data collection is started from the outer peripheral portion of the breast, but conversely, it may be started from a portion close to the nipple. Further, the shift position and the number of shifts may be changed according to the size of the breast.

  Next, a method for controlling the position and tilt angle of the probe so that the distance between the ultrasonic probe and the body surface is always sufficiently close and the ultrasonic beam is perpendicularly incident on the body surface will be described in detail.

ーブ１をできるだけ近づけかつ超音波ビームを体表９に垂直に入射させるためには、回帰直線Ｂ−Ｂとプローブ１の表面を平行にし、プローブ１と体表９の距離をプローブが体表

FIG. 5 shows the positional relationship between the probe 1 and the body surface 9 with the horizontal direction as the x-axis and the vertical direction passing through the horizontal rotation axis 8 as the y-axis. FIG. 5 shows a state before the tilt angle and vertical position of the probe 1 are optimized, and this state is indicated by a subscript i. The height of the fixed end 4 of the arm is y _i , the angle of the arm 2 is constant, θ ₀ , the tilt angle with respect to the arm 2 is θ _i , the table of the body surface 9 and the probe 1

In order to bring the probe 1 as close as possible and make the ultrasonic beam perpendicularly incident on the body surface 9, the regression line BB and the surface of the probe 1 are parallel to each other, and the distance between the probe 1 and the body surface 9 is determined by the probe.

ト角度をθ_ｉ＋１とすれば、図５から容易に分かるようにθ_ｉ＋１は以下のようになる、

Assuming that the angle is θ _{i + 1} , θ _{i + 1} is as follows, as can be easily seen from FIG.

Formula 1

ローブ１は右に回転することになる。

Lobe 1 will rotate to the right.

以下のようになる。

It becomes as follows.

Formula 2

したがって最適制御を行うには、現在のアームの固定端４の高さｙ_ｉとチルト角度θ_ｉをもと

と固定端４の高さをそれぞれθ_ｉ＋１、ｙ_ｉ＋１に設定すればよい。

Therefore, in order to perform optimum control, the height y _i of the fixed end 4 of the current arm and the tilt angle θ _i are used.

And the height of the fixed end 4 may be set to θ _{i + 1} and y _{i + 1} , respectively.

動する。この様子を図６に示す。図６では実線で描いたプローブ１はチルト回転前の位置を示し、チルト軸３を通りプローブ表面に平行な軸をＸ軸、垂直な方向（超音波ビーム方向）をＹ軸としている。この状態での体表上の点の座標はＰ（Ｘ，Ｙ）で表され、最短距離とな

で、チルト軸３を通り点線で描かれたプローブ表面に平行な軸をＸ_θ軸、垂直な軸をＹ_θ軸とする。この状態では体表の曲線上の点の座標はＱ（Ｘ_θ，Ｙ_θ）で表され、体表とプローブ表面

回転後の座標、Ｘ_θ、Ｙ_θは座標回転の公式から以下のようになる。

Move. This is shown in FIG. In FIG. 6, the probe 1 drawn with a solid line indicates the position before tilt rotation, and the axis passing through the tilt axis 3 and parallel to the probe surface is the X axis, and the perpendicular direction (ultrasound beam direction) is the Y axis. The coordinates of the point on the body surface in this state are represented by P (X, Y), which is the shortest distance.

The axis parallel to the probe surface drawn by the dotted line through the tilt axis 3 is defined as the _Xθ axis, and the vertical axis is defined as the _Yθ axis. In this state, the coordinates of the points on the body surface curve are represented by Q (X _θ , Y _θ ), and the body surface and the probe surface

Coordinates after the _rotation, X θ, Y θ is as follows from the formula of coordinate rotation.

Formula 3

Formula 4

この式で変換された新たな座標Ｑ（Ｘ_θ，Ｙ_θ）で最短距離の位置座標Ｑ（Ｘ_θｍ，Ｙ_θｍ）を求め、数式２

この値は数式２の値に等しくなる。

The position coordinate Q (X _θm , Y _θm ) of the shortest distance is obtained from the new coordinates Q (X _θ , Y _θ ) converted by this formula, and the formula 2

This value is equal to the value of Equation 2.

２、図５、図６では画像データを収集する視野５は四角な枠で示されているが、この枠内の断面像は多数の走査線によって形成されている。その様子を図７に示す。走査線以外は図６と共通である。プローブ１の左端で超音波の送受信が行われるとその反射波を検出して左端の１本の走査線が得られる。次に僅か右にずらして送受信を行うと次の走査線が得られ、これを右端まで繰り返して多数の走査線１１により断面像を形成する。各走査線の間隔は約０．３ｍｍであり、走査線の位置は図７のＸ座標に相当する。１本の走査線には反射波の強さとプローブ１から反射体までの距離すなわち図７のＹ座標の情報が含まれており、プローブ１に最も近い強い反射が体表９からの反射である。したがって、１枚の画像データが収集された時点で体表９の曲線の座標Ｐ（Ｘ，Ｙ）が得られ、これを用いて、プロー

In FIGS. 2, 5 and 6, the field of view 5 for collecting image data is shown as a rectangular frame, and a cross-sectional image in this frame is formed by a large number of scanning lines. This is shown in FIG. Except for the scanning line, it is the same as FIG. When ultrasonic waves are transmitted and received at the left end of the probe 1, the reflected wave is detected and one scanning line at the left end is obtained. Next, when transmission / reception is performed with a slight shift to the right, the next scanning line is obtained, and this is repeated to the right end to form a cross-sectional image with a large number of scanning lines 11. The interval between the scanning lines is about 0.3 mm, and the position of the scanning line corresponds to the X coordinate in FIG. One scanning line includes information on the intensity of the reflected wave and the distance from the probe 1 to the reflector, that is, the Y coordinate in FIG. 7, and the strong reflection closest to the probe 1 is the reflection from the body surface 9. . Therefore, when one piece of image data is collected, the coordinate P (X, Y) of the curve of the body surface 9 is obtained and used to

The coordinates P (X, Y) of the curve in the body surface 9 are not actually continuous, but the coordinates P (X _j , Y _j ) of 192 points. Can be sought. The slope of the regression line is α

枚の画像の走査が修了した時点のＹの値がそのままＹ_ｍとなる。また、回帰直線を求めるためには、回帰直線の公式から明らかなように各走査線ごとのＸ_ｊ、Ｙ_ｊの積あるいは２乗をもとめそれを加算してゆき、最後に割り算だけを行えばよいので、この場合も１枚の画像

は例えば１００μｓであり、走査線数を１９２本とすれば１９．２ｍｓで１枚の画像デー

The value of Y at the time when scanning of one image is completed becomes Y _m as it is. In order to obtain a regression line, as is apparent from the regression line formula, the product or square of X _j and Y _j for each scanning line is obtained and added, and finally only division is performed. It ’s good, so in this case too, one image

Is, for example, 100 μs. If the number of scanning lines is 192, one image data is obtained in 19.2 ms.

固定端４の上下移動およびチルト角度の制御により、プローブ１は体表９に平行かつ最短距離に設定される。その後、プローブ１は水平方向に回転を始める。プローブ１が回転す

固定端４の上下移動およびチルト角度を制御する。前述のように水平回転角度０．５度ごとに１／５０秒で１フレームの画像が得られるとし、制御の応答速度を例えば０．１秒とすれば、制御は５フレームすなわち２．５度あとの位置に対して実施されるが、体表９の形状の変化は緩やかなのでこの程度の応答速度でもあまり問題にならない。Before starting the examination, the probe 1 is in a park position sufficiently away from the body surface 9. When the inspection is started, the arm 2 is initially fixed at a position where the horizontal rotation angle is 0 degree and is set as a target.

The probe 1 is set parallel to the body surface 9 and at the shortest distance by the vertical movement of the fixed end 4 and the control of the tilt angle. Thereafter, the probe 1 starts to rotate in the horizontal direction. Probe 1 rotates

The vertical movement and tilt angle of the fixed end 4 are controlled. As described above, if an image of 1 frame is obtained in 1/50 seconds every horizontal rotation angle of 0.5 degrees, and the control response speed is 0.1 seconds, for example, the control is 5 frames, that is, 2.5 degrees. Although it is performed for a later position, the change in the shape of the body surface 9 is slow, so even a response speed of this level is not a problem.

  The control method described above is so-called feedback control in which the distance between the probe and the body surface and the angle of the probe is detected and the difference from the target value is zero, so that optimal and stable control is always possible.

  FIG. 8 shows another embodiment of the shape of the arm and the driving system. The arm 2 in FIG. 1 is linear, the tilt shaft 3 is shifted along the arm 2, and the fixed end 4 of the arm is fixed to the horizontal rotation shaft 8. On the other hand, the arm 12 in the embodiment of FIG. 8 is curved, and the tilt shaft 3 is coupled to one end thereof, and the position of the tilt shaft 3 with respect to the arm 12 is fixed. The other end of the arm 12 is inserted into a gear box 13 fixed to the upper part of the horizontal rotating shaft 8, and the arm 12 moves inside the gear box 13 by a gear not shown. The probe drawn by a dotted line at the position of the tilt axis 7 shows a state when the arm 12 moves in the gear box 13 and the probe 1 comes to a position close to the nipple. At this time, the horizontal rotation shaft 8 is slightly lowered and the tilt angle is also changed. The state in which the tilt axis is at the intermediate position is omitted in FIG. 8 for the sake of clarity. In this way, it is possible to reduce the vertical movement of the horizontal rotation shaft 8 and the change of the tilt angle.

  As described above in detail, according to the present invention, an image with high reproducibility is always obtained without deforming the breast by the water immersion method, the shift of the probe with a narrow field of view, and the up and down using the reflected signal of the ultrasonic wave. By moving and tilting feedback control, it is possible to obtain an excellent image by always minimizing the distance between the probe and the breast surface and making the ultrasonic beam perpendicularly incident on the body surface even for a subject having a large individual difference. In addition, since a probe equivalent to a commonly used probe can be used, the cost of the probe and the main unit is minimized, and an ultrasonic breast cancer screening device that is compatible with general-purpose ultrasonic diagnostic devices is also available. Can be provided.

Explanatory drawing of the ultrasonic probe control mechanism of the present invention Explanatory drawing of the positional relationship when the ultrasonic probe is rotated 180 degrees horizontally The figure which shows the whole system structure of this invention Explanatory drawing of conventional ultrasonic probe control mechanism Explanatory drawing showing the optimal control method of the ultrasonic probe Diagram showing control method when tilt angle is large Explanatory drawing of the method of calculating | requiring a movement distance and a tilt angle from ultrasonic reflected wave data. Other examples of the shape of the arm and the movement method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Arm which fixes ultrasonic probe 3 Tilt rotation axis of ultrasonic probe 4 Fixed end to horizontal rotation axis of arm 5 Field of view of ultrasonic image 8 Horizontal rotation axis which rotates ultrasonic probe horizontally 9 Breast surface (body surface)
10 Water tank 11 Scan line 12 Curved arm 13 Gearbox

Claims (4)

  An ultrasonic probe in which transducers are arranged in an array; a rotation mechanism that rotates the ultrasonic probe in a horizontal direction; a vertical movement mechanism that moves the ultrasonic probe up and down; and a shift mechanism that shifts the ultrasonic probe in the radial direction; An ultrasonic inspection unit or an ultrasonic inspection apparatus comprising an angle adjusting mechanism for changing the angle of the ultrasonic probe, and a liquid container for storing the ultrasonic probe and the liquid   2. The ultrasonic inspection unit or ultrasonic inspection apparatus according to claim 1, wherein a sensor for detecting a distance or an angle is provided in the vertical movement mechanism and the angle adjustment mechanism to control the vertical position and angle of the ultrasonic probe.   The vertical movement mechanism and the angle adjustment mechanism use the ultrasonic reflection information so that the distance between the subject and the ultrasound probe is as close as possible and the ultrasound beam is incident on the subject as vertically as possible. The ultrasonic inspection unit or the ultrasonic inspection apparatus according to claim 2, wherein the angle and the angle are controlled.   The ultrasonic inspection unit or ultrasonic inspection apparatus according to claim 1, wherein there are three or more radial shift positions by the shift mechanism.

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