JP2007037564A - Ultrasonograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonograph which constructs accurate three-dimensional ultrasonogram data. <P>SOLUTION: The ultrasonograph 1 which comprises an insertion portion 3 and an ultrasonic transducer 22 disposed at a distal end part 4 of the insertion portion, and acquires ultrasonic tomograms by inserting the insertion portion 3 inside the body of a subject and by scanning the inside of the body of the subject through mechanically rotating the ultrasonic transducer 22, wherein the ultrasonograph is equipped with a transmission coil 24 which is a position detecting means to detect the position and the orientation of the ultrasonic tomogram and an encoder 23 which is a rotary angle detecting means to detect a rotary angle of the ultrasonic transducer 22 at the distal end part 4 of the insertion portion 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

 The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to an ultrasonic diagnostic apparatus that generates an ultrasonic tomographic image of a subject from an ultrasonic signal obtained by transmitting and receiving ultrasonic waves to and from the subject.

 In order to diagnose the internal state of the subject or the like, the ultrasonic diagnostic apparatus transmits an ultrasonic wave to the inside of the subject or the like, and reflects the reflected ultrasonic wave reflected at the changing portion of the internal acoustic impedance of the subject or the like. By receiving, the internal state of the subject or the like is drawn as a cross-sectional view.

 Since an ultrasonic image obtained by an ultrasonic diagnostic apparatus can draw the inside of a subject or the like in real time, it is widely used for various diagnoses in the medical field. For example, in the medical field, an ultrasonic diagnostic apparatus inserts an ultrasonic probe having an ultrasonic transducer for transmitting and receiving ultrasonic waves into a body cavity, and draws the state of the subject in the body, thereby It is used for diagnosis in the body.

 As an example of an ultrasonic probe that is inserted into a body cavity of a subject, an ultrasonic endoscope that includes an ultrasonic transducer at a distal end portion of an insertion portion of an endoscope is known. As an example of this ultrasonic endoscope, ultrasonic waves are transmitted and received in a radial direction, that is, in a radial direction, in a plane orthogonal to the axial direction of the insertion portion in the portion where the ultrasonic transducer of the ultrasonic endoscope is provided. Thus, an ultrasonic endoscope called a radial scan type that obtains an ultrasonic tomographic image on a plane orthogonal to the axial direction is known.

 In recent years, it has been possible to draw and diagnose a state of an organ or the like in the body of the subject with a three-dimensional image for the purpose of grasping the shape of a tumor or the like generated in the body of the subject and measuring the volume. There is a growing need for possible ultrasound diagnostic devices. As an example of an ultrasonic diagnostic apparatus that draws a state of an internal organ or the like of a subject with a three-dimensional image, an ultrasonic diagnostic apparatus disclosed in Japanese Patent Laid-Open No. 10-248852 or Japanese Patent Laid-Open No. 2004-230193 is disclosed. And an ultrasonic diagnostic apparatus disclosed in Japanese Patent Publication No. Gazette.

 An ultrasonic diagnostic imaging apparatus disclosed in Japanese Patent Application Laid-Open No. 10-248852 includes an ultrasonic endoscope having an insertion portion, a position detection catheter having a position detection means at a distal end portion, and a position detection catheter. The apparatus includes a processing unit that acquires a position signal from the detection unit and a plurality of ultrasonic tomographic images obtained by the ultrasonic endoscope in synchronization and constructs three-dimensional data.

In addition, an ultrasonic diagnostic apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-230193 detects an ultrasonic probe inserted into a body cavity and a position and orientation of a scanning plane on which the ultrasonic probe performs ultrasonic scanning. And three-dimensional image processing means for creating an ultrasonic three-dimensional image based on ultrasonic tomographic image data obtained by scanning with an ultrasonic probe.
JP-A-10-248852 JP 2004-230193 A

 In the ultrasonic diagnostic imaging apparatus disclosed in Japanese Patent Application Laid-Open No. 10-248852, an ultrasonic endoscope that performs a radial scan by rotating an ultrasonic transducer with a DC motor is used. This ultrasonic endoscope has an insertion portion that is inserted into a body cavity and an operation portion that is provided at the proximal end of the insertion portion. A DC motor and a flexible shaft having one end connected to the rotating shaft of the DC motor are disposed inside the operation unit. On the other hand, an ultrasonic transducer is disposed at the distal end of the distal end hard portion of the insertion portion. The other end of the flexible shaft is connected to the ultrasonic transducer. The ultrasonic transducer is rotationally driven through a flexible shaft by rotating a DC motor.

 In the ultrasonic diagnostic imaging apparatus having the above-described configuration, the ultrasonic vibrator is rotationally driven through the flexible shaft. Therefore, when the flexible shaft is twisted, the rotation angle of the DC motor and the actual ultrasonic vibrator are A deviation occurs between the rotation angle and the rotation angle. Further, the amount of deviation between the rotation angle of the DC motor and the rotation angle of the ultrasonic vibrator is not constant because it is affected by the shape of the flexible shaft being bent. For this reason, a deviation occurs between the actual angle of the ultrasonic tomographic image and the angle of the ultrasonic tomographic image detected by the position detecting means. Therefore, a distortion occurs in a three-dimensional image constructed from a plurality of ultrasonic tomographic images obtained by an ultrasonic endoscope and position and angle information acquired in synchronization with the ultrasonic tomographic image, and the subject There was a problem that the inside of the drawing was not drawn accurately.

 Moreover, in the ultrasonic diagnostic apparatus disclosed in Japanese Patent Application Laid-Open No. 2004-230193, an ultrasonic probe to be inserted into a body cavity is on a plane around a predetermined position of the insertion axis and perpendicular to the insertion axis. An electronic radial scanning ultrasonic endoscope is used in which a plurality of ultrasonic transducers are arranged and a radial scan is performed by transmitting and receiving ultrasonic waves using the ultrasonic transducers.

 In the above electronic radial scanning ultrasonic endoscope, the ultrasonic transducer is driven to rotate in order to rotate the transmission / reception direction of the ultrasonic wave by the annular ultrasonic transducer array having a plurality of ultrasonic transducers at the tip. Therefore, a flexible shaft is not required. Therefore, there is no deviation between the angle of the ultrasonic tomographic image and the angle of the ultrasonic tomographic image detected by the position detection means, and no distortion occurs in the three-dimensional image constructed by the ultrasonic diagnostic apparatus.

 However, the ultrasonic transducer array is composed of approximately 100 to 200 ultrasonic transducers, and it is necessary to wire each of the plurality of ultrasonic transducers one by one. That is, 100 to 200 signal lines are inserted through the insertion portion of the electronic radial scanning ultrasonic endoscope. Further, a signal line for position detection means is also inserted through the insertion portion. For this reason, there has been a problem that the outer diameter of the insertion portion of the electronic radial scanning ultrasonic endoscope is increased, and the burden on the patient to be diagnosed is increased.

 The present invention has been made to solve the above-described problem, and an ultrasonic diagnostic apparatus capable of constructing accurate three-dimensional ultrasonic image data in an ultrasonic diagnostic apparatus for diagnosing the inside of a subject or the like. The purpose is to provide.

 In order to solve the above problems, an ultrasonic diagnostic apparatus of the present invention includes an insertion portion and an ultrasonic transducer disposed at a distal end portion of the insertion portion, and inserts the insertion portion into the body of a subject. Position detection for detecting the position and orientation of the ultrasonic tomographic image in an ultrasonic diagnostic apparatus that obtains an ultrasonic tomographic image by mechanically rotating the ultrasonic transducer and scanning the inside of the subject. And a rotation angle detection means for detecting the rotation angle of the ultrasonic transducer are provided at the distal end of the insertion portion.

 According to the present invention, an ultrasonic diagnostic apparatus capable of constructing accurate three-dimensional ultrasonic image data in an ultrasonic diagnostic apparatus for diagnosing the inside of a subject can be realized.

(First embodiment)
The first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an ultrasonic endoscope according to the first embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing the internal configuration of the distal end portion of the ultrasonic endoscope according to the first embodiment of the present invention. FIG. 3 is a configuration diagram of the ultrasonic diagnostic apparatus according to the embodiment of the present invention. FIG. 4 is a schematic diagram showing an example of a plurality of continuous ultrasonic tomographic images obtained by the ultrasonic diagnostic apparatus according to the embodiment of the present invention.

 FIG. 1 shows the overall configuration of the ultrasonic endoscope 2 according to the first embodiment of the present invention. The ultrasonic endoscope 2 includes an insertion portion 3 to be inserted into a body cavity of a subject, and an operation portion 5 provided at the proximal end of the insertion portion 3 for an operator to grasp and operate the ultrasonic endoscope 2. And a sub operation unit 6 incorporating a motor (not shown), which is a rotational driving means for rotationally driving an ultrasonic transducer 22 to be described later. A position detection connector 7 for connecting to a position detection device 11 which is an external device to be described later is provided on the operation unit 5. A scope connector 9 for connecting to an optical observation device 13 which is an external device described later is provided on the operation unit 5 via a cable. In addition, an ultrasonic connector 8 for connecting to an ultrasonic diagnostic apparatus 12 which is an external apparatus to be described later is provided in the sub operation unit 6 via a cable. In the ultrasonic endoscope 2 shown in FIG. 1, the position detection connector 7 is provided in the operation unit 5. However, the position detection connector 7 is provided in the ultrasonic connector 8. It is good also as a structure provided in the location different from the location shown in figure.

 FIG. 2 is a partial cross-sectional view for explaining the configuration of the distal end portion 4 of the insertion portion 3 of the ultrasonic endoscope 2 according to the first embodiment of the present invention. A hard portion 21 made of a hard material is disposed at the distal end portion 4. A vibrator housing member 41 that is hollow and has a substantially cylindrical shape is fitted to the distal end side of the hard portion 21 with its central axis oriented parallel to the insertion axis of the distal end portion 4. The tip of the vibrator housing member 41 is sealed with a sealing member 41a. The vibrator housing member 41 is a member having a substantially cylindrical space inside.

 A through hole 46 is formed in the hard portion 21 coaxially with the center axis of the vibrator housing member 41 fitted to the distal end side of the hard portion 21, that is, parallel to the insertion axis of the distal end portion 4. The space inside the transducer housing member 41 and the space inside the insertion portion 3 communicate with each other through the through hole 46. A bearing 43 having water-tightness is fitted to the inner peripheral surface on the distal end side of the through hole 46.

 In a space inside the transducer housing member 41, a transducer holder 42 for supporting an ultrasonic transducer 22 described later is disposed. On the base end surface of the vibrator holder 42, a rotation shaft portion 42a protrudes in the base end direction. The vibrator holder 42 is rotatably supported by a bearing 43 with the central axis of the rotating shaft portion 42 a and the central axis of the through hole 46 being coaxial. That is, the vibrator holder 42 is supported so as to be rotatable around the insertion axis of the distal end portion 4.

 The ultrasonic transducer 22 is supported by the transducer holder 42 in the space inside the transducer housing member 41 with the surface for transmitting and receiving ultrasonic waves directed in a direction orthogonal to the central axis of the rotation shaft portion 42a. . That is, the direction in which the ultrasonic transducer 22 transmits and receives waves is a direction orthogonal to the insertion axis of the distal end portion 4. The space inside the transducer housing member 41 is filled with an ultrasonic transmission medium 44.

 An encoder 23, which is a rotation angle detecting means having a function of detecting a rotation angle, is disposed in a through hole 46 formed in the hard portion 21. The encoder 23 has a rotatable shaft portion and outputs an electrical signal in accordance with the rotation angle of the shaft portion. The encoder 23 is disposed on the base end side of the bearing 43 with the rotation axis of the shaft portion being coaxial with the central axis of the through hole 46. The distal end side of the shaft portion of the encoder 23 is mechanically connected to a rotating shaft portion 42 a formed to protrude in the proximal direction of the transducer holder 42 that supports the ultrasonic transducer 22. That is, the ultrasonic transducer 22 and the shaft portion of the encoder 23 rotate integrally. The rotation angle of the ultrasonic transducer 22 is detected by the encoder 23.

 The distal end of the flexible shaft 25 is mechanically connected to the proximal end side of the shaft portion of the encoder 23. On the other hand, the base end of the flexible shaft 25 is inserted into the insertion portion 3 and mechanically connected to a rotation shaft of a motor which is a rotation driving means (not shown) provided in the sub operation portion 6. That is, the rotation shaft of the motor provided in the operation unit 6 is mechanically connected to the flexible shaft 25, the shaft unit of the encoder 23, and the vibrator holder 42 in the ultrasonic endoscope 2. These rotate together. Therefore, the ultrasonic transducer 22 supported by the transducer holder 42 is driven to rotate by driving a motor provided in the sub operation unit 6.

 In addition, a transmission coil 24 for generating a magnetic field as a position detecting means is disposed inside the hard portion 21. The transmission coil 24 is connected to a coil drive circuit 34 to be described later via a coil cable 45 inserted into the insertion portion 3.

 Here, since the ultrasonic transducer 22 and the encoder 23 are provided close to each other, and the encoder 23 and the transmission coil 24 are respectively disposed in the hard portion 21 that is a hard member, the relative positions thereof are set. Will not change.

 In the ultrasonic endoscope 2 according to the embodiment of the present invention shown in FIG. 2, one transmission coil 24 is arranged inside the hard portion 21, but transmission is performed inside the distal end portion 4. A plurality of coils 24 may be arranged. In the case where a plurality of transmission coils 24 are arranged inside the distal end portion 4, at least one transmission coil 24 is arranged inside the hard portion 21.

 Although not shown in FIG. 2, the hard portion 21 is provided with an imaging device having a CCD, an illumination device, and the like for optically observing the inside of the body cavity.

 FIG. 3 shows a configuration diagram of the ultrasonic diagnostic apparatus 1 according to the embodiment of the present invention. In FIG. 3, solid and broken arrows indicate the electrical connection between the parts in the ultrasonic diagnostic apparatus 1 and the direction of transmission and reception of signals and data. The ultrasonic diagnostic apparatus 1 includes an ultrasonic endoscope 2, an optical observation apparatus 13, an ultrasonic tomographic image processing apparatus 12, an image processing apparatus 14, and a position detection apparatus 11. An ultrasonic connector 8 and a scope connector 9 provided in the ultrasonic endoscope 2 are connected to an ultrasonic tomographic image processing apparatus 12 and an optical observation apparatus 13, respectively. In addition, the ultrasonic endoscope 2 is electrically connected to the position detection device 11 via a cable connected to the position detection connector 7.

 The position detection device 11 includes a coil drive circuit 34 for exciting the transmission coil 24 disposed in the hard portion 21 of the ultrasonic endoscope 2 and a plurality of magnetic fields generated by the transmission coil 24. A reception antenna 31 having a reception coil 32 and a position calculation circuit 33 for calculating the position and orientation of the transmission coil 24 from a signal output from the reception antenna 31 are configured.

 The image processing device 14 is connected to the ultrasonic tomographic image processing device 12 and the position detection device 13.

 The operation of the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention having the above-described configuration will be described below. In the following description of the action, it is assumed that a plurality of transmission coils 24 are disposed at the distal end portion 4 of the ultrasonic endoscope 2.

 By operating the ultrasonic tomographic image processing apparatus 12, a motor provided in the sub operation unit 6 of the ultrasonic endoscope 2 is driven. The rotational force of the rotation shaft of the motor is transmitted to the shaft portion of the encoder 23 and the transducer holder 42 that supports the ultrasonic transducer 22 by the flexible shaft 25 inserted into the insertion portion 3. The ultrasonic transducer 22 supported by the transducer holder 42 is orthogonal to the insertion axis of the distal end portion 4 of the ultrasonic endoscope 2 by repeatedly transmitting and receiving ultrasonic waves while rotating in the body cavity of the subject. Scan radially in the plane. In general, this scanning method is known as radial scanning.

 The ultrasonic transducer 22 converts reflected ultrasonic waves received by radial scanning into echo signals that are electrical signals, and outputs the echo signals to the ultrasonic tomographic image processing apparatus 12. The ultrasonic tomographic image processing device 12 performs processing such as envelope detection, logarithmic amplification, A / D conversion, and coordinate conversion from a polar coordinate system to an orthogonal coordinate system on the input echo signal, and Generate an ultrasonic tomogram of the body. The ultrasonic tomographic image processing apparatus 12 generates one piece of ultrasonic tomographic image data for one radial scan in which the ultrasonic transducer 22 rotates once. The ultrasonic tomographic image data generated by the ultrasonic tomographic image processing device 12 is output to the image processing device 14.

 The encoder 23 detects the rotation of the shaft portion of the encoder 23 by the sensor portion, and generates and outputs a pulse signal according to the rotation of the shaft portion. By counting the pulse signals output from the encoder 23, the rotation angle of the ultrasonic transducer 22 mechanically connected to the shaft portion of the encoder 23 can be calculated. More specifically, the encoder 23 generates, for example, a signal of 1 pulse per rotation (hereinafter referred to as a Z-phase signal), a signal of 255 pulses per rotation (hereinafter referred to as an A-phase signal), and the like. In this case, the angle of rotation of the ultrasonic transducer 22 is calculated by counting the number of pulses of the A phase signal using the Z phase signal as a reference for the rotational position. When 255 pulses of the A phase signal are generated per rotation by the encoder 23, the ultrasonic transducer 22 is rotated about 1.4 degrees per pulse.

 On the other hand, the coil drive circuit 34 incorporated in the position detection device 11 supplies magnetic field generation currents having different frequencies to the plurality of transmission coils 24 disposed at the distal end portion 4 of the ultrasonic endoscope 2. It is supplied via the position detection connector 7 and the coil cable 45. The plurality of transmission coils 24 supplied with different magnetic field generation currents generate magnetic fields of different frequencies toward the surrounding space. Here, the coil driving circuit 34 supplies a different frequency to each transmission coil 24 because the position calculation circuit 33 described later uses a magnetic field having a specific frequency generated by each transmission coil 24. This is to identify each transmission coil 24.

 The magnetic field generated by the transmission coil 24 is detected by the reception antenna 31. The receiving antenna 31 converts the detected magnetic field into an electric current and outputs it as an electric signal to the position calculating circuit 33.

 The position calculation circuit 33 performs A / D conversion on the electrical signal output from the reception antenna 31, identifies a frequency, and calculates a position vector representing the position of each transmission coil 24. Here, the origin at the time of calculating the position vector is assumed as a specific position of the receiving antenna 31. The position calculation circuit 33 outputs the position vector of each transmission coil 24 to the image processing apparatus 14 as position information data.

 The image processing device 14 performs image processing from the position information data output from the position detection device 11 and the ultrasonic tomographic image data output from the ultrasonic tomographic image processing device 12.

 As an example of image processing by the image processing apparatus 14, the construction of a three-dimensional ultrasonic image will be described below.

 The image processing device 14 stores the ultrasonic tomographic image data output from the ultrasonic tomographic image processing device 12 and the position information data output from the position detecting device 11 in an image memory. A two-dimensional ultrasonic tomographic image data group is obtained by processing the ultrasonic tomogram data group and the positional information data of each transmission coil acquired in synchronization with each ultrasonic tomographic image by the image processing device 14. Are arranged in a three-dimensional space with a position and a direction, for example, as shown in the schematic diagram of FIG. That is, each pixel having luminance that constitutes two-dimensional ultrasonic tomographic image data is arranged in a three-dimensional space. Here, the luminance of each pixel represents the intensity of the echo signal received by the ultrasonic transducer 22. The image processing apparatus 14 converts each ultrasonic tomographic image data based on a plurality of ultrasonic tomographic image data and position information data obtained by continuing radial scanning while moving the distal end portion 4 in the body of the subject. Each pixel to be configured is arranged in a three-dimensional space. The image processing device 14 acquires the intensity distribution of the echo signal at each position in the three-dimensional space. Further, the image processing apparatus 14 complements data between adjacent ultrasonic tomographic images, thereby constructing a three-dimensional ultrasonic image in the body of the subject and outputting it to a monitor (not shown). Details of the technique for constructing the three-dimensional ultrasonic image as described above are disclosed in Japanese Patent Application Laid-Open No. 10-248852.

 As described above, in the first embodiment of the present invention, in the ultrasonic endoscope 2, the transmission coil 24 for detecting the position, the ultrasonic transducer 22, and the rotation angle of the ultrasonic transducer 22 are used. And an encoder 23 for detecting the above is disposed on the hard portion 21 of the distal end portion 4. Thereby, when the encoder 23 detects the rotation angle of the ultrasonic transducer 22, it is not affected by the twist of the flexible shaft 25 that rotationally drives the ultrasonic transducer 22. That is, the position information data of the ultrasonic endoscope detected by the position detection device 11 and the rotational angle of the ultrasonic transducer 22 detected by the encoder 23, that is, the direction of the rotational direction of the ultrasonic tomographic image in this case are shifted. Will not occur. Therefore, according to the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention, it is possible to construct accurate three-dimensional ultrasonic image data.

 Further, according to the first embodiment of the present invention, it is necessary to insert a large number of signal lines into the insertion portion 3 as compared with an electronic radial scanning ultrasonic diagnostic apparatus using an annular ultrasonic transducer array. Therefore, the outer diameter of the insertion portion 3 can be reduced. If the diameter of the insertion portion 3 is reduced, the insertability of the insertion portion 3 into the body cavity is improved, and the burden on the subject associated with the examination can be reduced.

 For this reason, according to the first embodiment of the present invention, it is possible to construct an ultrasound diagnostic apparatus that can construct accurate three-dimensional ultrasound image data and has less burden on the subject.

 The use of the three-dimensional ultrasonic image data constructed by the ultrasonic diagnostic apparatus 1 according to the first embodiment of the present invention described above directly uses the three-dimensional image to directly analyze the internal organs of the subject. The present invention is not limited to the use of diagnosing the condition, but can be used in the following other uses. For example, at the time of diagnosis in the body of the subject by the ultrasonic endoscope, the current ultrasonic scanning plane obtained by the position detecting means is displayed on the three-dimensional ultrasonic image in the body of the subject that has been constructed in advance. An ultrasonic diagnostic apparatus that superimposes and displays the position and orientation state is conceivable. According to this ultrasonic diagnostic apparatus, it is possible for the operator to easily understand which part of the body of the subject is ultrasonically scanned and in what direction. Such a technique for facilitating diagnosis by an ultrasonic endoscope using a three-dimensional image in the body of a subject is disclosed in Japanese Patent Application Laid-Open Nos. 2004-230193 and 2004-113629. Yes.

 In the first embodiment, the position of the insertion portion 3 is detected by detecting a magnetic field by a coil. However, an acceleration sensor or the like is provided in another position detection unit, for example, the hard portion 21 of the insertion portion 3. It is good also as a structure which detects the position of the insertion part 3 by arrange | positioning.

(Second Embodiment)
FIG. 5 is a configuration diagram of an ultrasonic endoscope according to the second embodiment of the present invention. FIG. 6 is a partial cross-sectional view showing the internal configuration of the distal end portion of the ultrasonic endoscope according to the second embodiment of the present invention.

  In the above-described first embodiment of the present invention, the motor for rotating the ultrasonic transducer 22 is disposed in the sub operation unit 6, but the motor is disposed at the tip of the ultrasonic endoscope. It is also possible to adopt a configuration in which the part is disposed. An example of the configuration will be described with reference to FIGS. 5 and 6 as a second embodiment of the present invention. In the following description, the same components as those in the first embodiment are assigned the same reference numerals and description thereof is omitted.

 FIG. 5 shows an overall configuration of an ultrasonic endoscope 51 according to the second embodiment of the present invention. The ultrasonic endoscope 51 includes an insertion portion 52 that is inserted into the body cavity of the subject, and an operation portion 5 that is provided at the proximal end of the insertion portion 52 and grips and operates the ultrasonic endoscope 51. Configured. A position detection connector 7 for connecting to the position detection device 11 which is an external device is provided in the operation unit 5. A scope connector 9 for connecting to the optical observation device 13 which is an external device is provided on the operation unit 5 via a cable. In addition, an ultrasonic connector 8 for connecting to an ultrasonic diagnostic apparatus 12 that is an external apparatus is provided on the operation unit 5 via a cable. In the ultrasonic endoscope 51 shown in FIG. 5, the position detection connector 7 is provided in the operation unit 5, but the position detection connector 7 is provided in the ultrasonic connector 8, etc. It is good also as a structure provided in the location different from the location shown in figure.

 FIG. 6 is a cross-sectional view for explaining the configuration of the distal end portion 53 of the insertion portion 52 of the ultrasonic endoscope 51. The distal end portion 53 of the ultrasonic endoscope 51 according to the second embodiment shown in FIG. 6 is different from the configuration of the distal end portion 4 of the ultrasonic endoscope 2 shown in the first embodiment. In other words, a motor 62 that is a rotation driving means for rotating the ultrasonic transducer 22 is disposed inside the hard portion 61. The motor 62 is disposed on the proximal end side of the encoder 23. The shaft portion of the encoder 23 and the rotating shaft of the motor 62 are mechanically connected. That is, the rotating shaft of the motor 62 is mechanically connected to the shaft portion of the encoder 23 and the vibrator holder 42, and these are rotated integrally. By driving the motor 62, the ultrasonic transducer 22 supported by the transducer holder 42 is rotationally driven.

 Since the ultrasonic transducer 22 and the encoder 23 are provided close to each other, and the encoder 23, the motor 62, and the transmission coil 24 are respectively disposed in the hard portion 61 that is a hard member, the relative positions of each other. Will not change.

 The operation of the ultrasonic diagnostic apparatus 1 according to the second embodiment of the present invention will be described below.

 By operating the ultrasonic tomographic image processing apparatus 12, a motor 62 built in the distal end portion 53 of the ultrasonic endoscope 51 is driven. As the rotation shaft of the motor 62 rotates, the encoder 23 and the vibrator holder 42 that supports the ultrasonic vibrator 22 are rotationally driven. The ultrasonic transducer 22 supported by the transducer holder 42 performs radial scanning by repeatedly transmitting and receiving ultrasonic waves while rotating in the body cavity of the subject.

 In addition, the other operations in the second embodiment are the same as those in the first embodiment.

 In the above-described second embodiment of the present invention, in the ultrasonic endoscope 51, the transmission coil 24 for detecting the position, the ultrasonic transducer 22, and the rotation angle of the ultrasonic transducer 22 are detected. The encoder 23 and the motor 62 for rotationally driving the ultrasonic transducer 22 are disposed on the hard portion 61 of the distal end portion 53. According to this configuration, in the first embodiment, the flexible shaft 25 provided for transmitting the rotational force of the motor built in the sub operation unit 6 to the ultrasonic transducer 22 is not necessary. For this reason, the structure inside the insertion part 52 can be decreased, and the outer diameter of the insertion part 52 can be made small. By reducing the outer diameter of the insertion portion 52, the insertability of the insertion portion 52 into the body cavity is improved, and the burden on the subject associated with the examination can be reduced.

 Other effects in the second embodiment are the same as those in the first embodiment.

(Third embodiment)
FIG. 7 is a configuration diagram of an ultrasonic diagnostic apparatus according to the third embodiment of the present invention. FIG. 8 is a partial cross-sectional view showing the internal configuration of the distal end portion of the ultrasonic endoscope according to the third embodiment of the present invention.

  In the first embodiment and the second embodiment described above, the transmission coil 24 for generating a magnetic field is disposed at the insertion portion of the ultrasonic endoscope, and is disposed outside the subject. Although the configuration is such that the magnetic field is detected by the receiving antenna 31, a configuration in which the transmission / reception of the magnetic field is reversed is also possible. An example of the configuration will be described as a third embodiment of the present invention with reference to FIGS. In the following description, the same components as those in the first embodiment and the second embodiment are denoted by the same reference numerals and description thereof is omitted.

 As shown in FIG. 8, the ultrasonic endoscope 51a of the ultrasonic diagnostic apparatus 101 according to the third embodiment is similar to the ultrasonic endoscope 51 in the second embodiment of the insertion portion 52a. The front end portion 53 a includes a motor 62 and an encoder 23. Around the motor 62, a magnetic shield member 63 made of a magnetic material, such as iron, for shielding a magnetic field generated by the motor 62 is disposed. The magnetic shield member 63 is composed of one or a plurality of members, and is disposed so as to cover the periphery of the motor 62. Further, unlike the second embodiment, the distal end portion 53a of the ultrasonic endoscope 51a is provided with a receiving coil 31a inside the hard portion 21.

 On the other hand, as shown in FIG. 7, in the ultrasonic diagnostic apparatus 101 according to the third embodiment, the position detection apparatus 11a includes a transmission coil 24a for generating a magnetic field and a transmission having a plurality of transmission coils 24a. The antenna 24b and a coil drive circuit 34 for exciting the plurality of transmission coils 24a are configured. The position detection device 11a includes a position calculation circuit 33a that is electrically connected to the reception coil 31a disposed in the insertion portion 52a of the ultrasonic endoscope 51a. The position calculation circuit 33a includes a filter 35 that is a filter circuit having a function of removing a noise component mixed in the electric signal from the reception coil 31a. Here, the noise component is a noise component generated by unnecessary magnetism and mixed in an electric signal, and may be simply referred to as magnetic noise.

 The operation of the ultrasonic diagnostic apparatus 101 according to the third embodiment of the present invention will be described below. As in the second embodiment, by operating the ultrasonic tomogram processing apparatus 12, the motor 62 built in the distal end portion 53a of the ultrasonic endoscope 51a is driven. As the ultrasonic transducer 22 is rotationally driven by the motor 62, the ultrasonic endoscope 51a performs radial scanning. During this radial scanning, the coil drive circuit 34 built in the position detection device 11 supplies magnetic field generation currents having different frequencies to the plurality of transmission coils 24a disposed in the transmission antenna 24b. The plurality of transmission coils 24a supplied with different magnetic field generation currents generate magnetic fields of different frequencies toward the surrounding space.

 The magnetic field generated by the transmission coil 24a is detected by the reception coil 31a disposed at the distal end portion 53a of the ultrasonic endoscope 51a. The receiving coil 31a converts the detected magnetic field into an electric current and outputs it as an electric signal to the position calculating circuit 33a of the position detecting device 11a.

 The position calculation circuit 33a separates the electrical signal output from the reception coil 31a into a signal component and a noise component by the filter 35, and determines the positional relationship between each transmission coil 24a and the reception coil 31a from the signal component of the electrical signal. calculate. The position detection device 11a outputs the positional relationship between each transmission coil 24a and the reception coil 31a to the image processing device 14 as position information data.

 Other operations in the third embodiment are the same as those in the first embodiment and the second embodiment.

In the above-described third embodiment of the present invention, the magnetic shield member 63 is disposed around the motor 62 for rotationally driving the ultrasonic transducer 22. Further, a filter 35, which is a filter circuit having a function of removing a noise component mixed in an electric signal from the receiving coil 31a, is disposed in the position calculation circuit 33a. According to this configuration, the magnetic field generated by the motor 62, which is generally the source of magnetic noise, is shielded, and magnetic noise is prevented from being mixed into the electrical signal output from the receiving coil 31a to the position calculating circuit 33a. can do. In addition, since the motor 62 and the receiving coil 31a are close to each other, the position detection can be performed even when an electrical signal output from the receiving coil 31a to the position calculating circuit 33a is mixed with magnetic noise generated from the motor 62. Magnetic noise can be removed by the filter 35 provided in the circuit 33a. Therefore, according to the third embodiment, since accurate position information data can be obtained without being affected by the magnetic noise caused by the motor 62, accurate three-dimensional ultrasound image data is constructed. It becomes possible to do.
Other effects in the third embodiment are the same as those in the first embodiment and the second embodiment.

 In the third embodiment, a transmission antenna 24b that generates a magnetic field is disposed outside the subject, and the magnetic field is detected by the reception coil 31a disposed in the insertion portion 52a of the ultrasonic endoscope 51a. However, it is also possible to adopt a configuration in which the transmission / reception of the magnetic field is reversed. Since the influence of the magnetic noise caused by the motor 62 is not limited to the receiving coil 31a, a transmitting coil corresponding to the transmitting antenna 24b is provided in the insertion portion 52a, and the coil provided outside the subject is used. A configuration that receives a magnetic field is also effective.

 In the third embodiment, the magnetic shield member 63 is disposed around the motor 62 as an example of the magnetic noise generation source. However, there are other magnetic noise generation sources in the ultrasonic diagnostic apparatus 101. In this case, it goes without saying that another magnetic shield member is provided around the magnetic noise generation source.

 In the third embodiment, the magnetic shield member 63 and the filter 35 are provided together in order to reduce the influence of magnetic noise on the electrical signal output from the receiving coil 31a to the position calculating circuit 33a. Although it was set as the structure, the structure which comprises either one may be sufficient.

1 is a configuration diagram of an ultrasonic endoscope according to a first embodiment. FIG. It is a fragmentary sectional view which shows the internal structure of the front-end | tip part of the ultrasonic endoscope which concerns on 1st Embodiment. 1 is a configuration diagram of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. It is a schematic diagram which shows an example of a several continuous ultrasonic tomogram. It is a block diagram of the ultrasonic endoscope which concerns on 2nd Embodiment. It is a fragmentary sectional view which shows the internal structure of the front-end | tip part of the ultrasonic endoscope which concerns on 2nd Embodiment. It is a block diagram of the ultrasound diagnosing device which concerns on 3rd Embodiment. It is a fragmentary sectional view which shows the internal structure of the front-end | tip part of the ultrasonic endoscope which concerns on 3rd Embodiment.

Explanation of symbols

 4 tip portion, 21 hard portion, 22 ultrasonic transducer, 23 encoder, 24 transmission coil, 25 flexible shaft, 41 transducer housing member, 41a sealing member 42 transducer holder, 42a rotating shaft portion, 43 bearing, 44 super Sonic transmission medium, 45 coil cable

Claims (4)

A subject having an insertion portion and an ultrasonic transducer disposed at a distal end of the insertion portion, inserting the insertion portion into a subject or the like and mechanically rotating the ultrasonic transducer; In an ultrasonic diagnostic apparatus that obtains an ultrasonic tomographic image by ultrasonically scanning the inside of
Position detecting means for detecting the position and orientation of the ultrasonic tomographic image;
An ultrasonic diagnostic apparatus characterized in that a rotation angle detecting means for detecting a rotation angle of the ultrasonic transducer is provided at a distal end portion of the insertion portion.  The ultrasonic diagnostic apparatus according to claim 1, wherein a rotation driving means for rotating the ultrasonic transducer is provided at a distal end portion of the insertion portion. The ultrasonic diagnostic apparatus according to claim 2, wherein a magnetic shield member made of a magnetic material is disposed around the rotation driving unit. The position detecting means includes one or a plurality of first coils disposed in the insertion portion and one or a plurality of second coils disposed at a predetermined predetermined position outside the subject. And calculating a relative position between the first coil and the second coil by transmitting and receiving a magnetic field between the first coil and the second coil. 2. A filter circuit for separating a magnetic noise component mixed in the electric signal with respect to an electric signal output from the first coil or the second coil in accordance with the magnetic field. 2. The ultrasonic diagnostic apparatus according to 2 or 3.

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