JP2005137581A - Dynamic image capturing apparatus for transverse section of somatic tissue using plurality of ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic image capturing apparatus which is not a large apparatus like an MRI or a CT, has portability, is used in fields, and realizes measurement of images of the transverse section of somatic tissues as a dynamic image. <P>SOLUTION: A plurality of ultrasonic probes are fixed on a fixing device comprising a link mechanism equipped with an angle sensor provided on each joint, and are disposed in the periphery of the somatic tissues or a subject for measurement. A space between each probe and the somatic tissue is filled with an acoustic coupling material. A probe switching part selects a probe among a plurality of probes for the measurement of the images, and image data measurement part measures images of the cross section of the somatic tissues from the selected probe. An image data synthesizing part synthesizes the images of the transverse section of the somatic tissues by joining the images of the fragments, and a dynamic image display part displays the dynamic image by displaying the synthesized image successively through repeating the synthesized image one by one. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention arranges a plurality of ultrasonic probes around the body tissue, captures images from them at high speed, and superimposes them on the positions determined by the means for measuring their positions. The present invention relates to a method, an apparatus, and a program for capturing a moving image of a cross-section of a body tissue using a plurality of ultrasonic probes that can be observed instantaneously and as a moving image.

  If you can visualize fat, muscle, bone, etc. in the cross section of body tissue and present it to the user, it will be very important from the viewpoint of health management for prevention of lifestyle-related diseases, exercise management of athletes, beauty etc. significant.

  Conventionally, there are only devices that enable such observations other than X-ray CT and MRI, but in this case, the device is very expensive and large-scale, so that ordinary people can easily measure it. It was impossible.

  An apparatus (Patent Document 1) for measuring a limb cross section using an ultrasonic diagnostic apparatus and a mechanism for rotating the probe around the limb has been proposed. It takes a long time to measure while moving the object, and the burden on the person to be measured is large, and it is impossible to display the measurement image as a continuous moving image. In addition, this apparatus has a disadvantage that the body to be measured must be immersed in a water tank and the person to be measured gets wet.

In addition, for the purpose of expanding the measurement range of the B-mode image of the ultrasonic diagnostic apparatus, a method of synthesizing a plurality of images taken while moving the probe (Patent Documents 2 and 3) has been devised. In the method, it is difficult to accurately capture the entire cross-section of the body tissue from the displacement at the time of probe movement, and it is impossible to observe as a moving image because of the time required for the probe movement over a wide range.
JP 2001-87267 A JP 2001-95804 A JP 2003-93382 A

  The present invention has been made in view of the above problems, and its purpose is not a large-scale device such as MRI or CT, but a cross-sectional image of body tissue, which is portable and can be used in a field, etc. And it is providing the method, apparatus, and program which implement | achieve measurement as a moving image.

  In order to achieve the above object, a moving image photographing method of a body tissue cross section using a plurality of ultrasound probes of the present invention includes a plurality of ultrasound probes capable of measuring an ultrasound B-mode image, The probe for performing image measurement is sequentially selected from the plurality of probes, and the body tissue fragment images from the selected probes are sequentially measured, and the sequential measurement is performed. A plurality of the fragment images thus formed are joined together to synthesize a body tissue cross-sectional image, and the synthesized image is repeatedly displayed continuously to display a moving image.

  Further, a moving image photographing apparatus for a body tissue cross section using a plurality of ultrasonic probes of the present invention includes a plurality of ultrasonic probes capable of measuring an ultrasonic B-mode image, a fixture for fixing them, a probe, An acoustic coupling material that fills a space between body tissues, a probe switching unit that selects which probe to perform image measurement from among a plurality of probes, and an image data measurement unit that measures an image of a fragment from the probe; The image data combining unit that combines the images of the fragments to combine the body tissue cross-sectional images and the moving image display unit that displays the moving images by continuously displaying the combined images.

  In addition, the moving image photographing program of a body tissue cross section using a plurality of ultrasonic probes of the present invention includes a plurality of ultrasonic probes capable of measuring an ultrasonic B-mode image, and an acoustic coupling material around the body tissue. And sequentially selecting a probe for performing image measurement from the plurality of probes, sequentially measuring fragment images of the body tissue from the selected probe, and sequentially measuring the plurality of fragment images. Are combined, a body tissue cross-sectional image is synthesized, and the synthesized image is repeatedly displayed one after another and each procedure for displaying a moving image is executed.

  In the moving image photographing method, apparatus, and program for cross-section of body tissue using a plurality of ultrasonic probes of the present invention, the body is obtained by synthesizing images obtained by a plurality of ultrasonic probes capable of transferring image data at high speed. The cross-sectional image of the tissue can be measured as a moving image, the burden on the person being measured is small, and measurement in the field is possible.

  In order to provide a method, apparatus, and program that can measure a cross-sectional image of body tissue as a moving image in a field, etc., and to disseminate them inexpensively, a general-purpose personal computer Alternatively, it is realized with the simplest possible configuration using an embedded microprocessor or the like.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an outline of the system of the present invention. As shown in this figure, a plurality of ultrasonic probes are fixed on a fixture composed of a link mechanism having an angle sensor at each joint, and are arranged around a body tissue to be measured. As shown in the figure, the space between each probe and the body tissue is filled with an acoustic coupling material.

  The probe switching unit selects which probe to perform image measurement from among a plurality of probes, and the image data measurement unit measures a body tissue fragment image from the selected probe. The image data synthesizing unit stitches the fragment images together to synthesize a body tissue cross-sectional image, and the moving image display unit repeats the synthesized images one after another to display them continuously.

  Here, the image data synthesis unit and the moving image display unit can be configured using, for example, a personal computer. In the case of a prototype system, the personal computer uses a digital I / O board for sending probe switching commands to the probe switching device, an encoder board for reading angle values from the angle sensor, and image data from the image data measurement unit at high speed. USB interface to read in. Processing relating to image data synthesis and moving image display is realized as software on a personal computer.

  If a personal computer is used, data management is easy and convenient, but if downsizing is desired, it can be configured using a board-type computer, PLD, FPGA, PIC, etc. according to the purpose. It is. Details of each part will be described below.

[Ultrasonic probe]
In order to synthesize the entire cross section of the body tissue, it is necessary to be able to measure at least the center of the body tissue when measuring the fragment image with the ultrasonic probe. Furthermore, since an acoustic coupling material is usually interposed between the probe and the limb, the measurement range must be at least 10 cm in the depth direction, and the focus position in the depth direction can be set arbitrarily. It is. In addition, as shown in the left side of FIG. 2 (a), a normal ultrasonic probe is designed to have a narrow effective measurement range with respect to the lateral width of its outer shape. In this case, considering combining the fragment images using a plurality of probes, a space that cannot be measured is created as shown on the right of FIG. 2 (a), so as shown in FIG. 2 (b), It is desirable to design the outer shape of the probe as close as possible to the effective width. This problem can be solved by taking out the ultrasonic vibration element array inside the housing case of a commercially available probe and placing it in a case having the same size as the width of the element array. This case can be made by processing a material such as acrylic or vinyl chloride and sealing it with silicone rubber for waterproofing from the outside. As a result, the lateral width of the measurable B-mode image can be made sufficiently wider than the lateral width of the probe outer shape.

  An ultrasonic B-mode image is obtained by generating a tomographic image in the scanning range by collecting a plurality of ultrasonic transducers in a line and collecting reflected signals while sequentially scanning the transducers. In clinical medical equipment, inspection using this image is generally performed, but the imaging range is limited to the width of the vibration element array.

〔Fixture〕
The fixture includes a link that fixes each probe and a joint that connects the links. Since the joint is detachable, the overall size (number of links) can be freely adjusted. Moreover, the geometric relative position of each probe can be measured by providing the joint with an angle sensor. Thus, the fixture is composed of a link mechanism provided with an angle sensor, and the resolution of the angle sensor needs to be sufficiently high so that the synthesis can be performed with high accuracy. The exemplary system uses an encoder with an accuracy of 0.25 degrees. When the size of the measurement target is known to some extent, the probe arrangement may be fixed as shown in FIG. In this case, an angle sensor is not necessary. Furthermore, it is possible to configure an annular probe as shown in FIG.

[Acoustic coupling material]
The acoustic coupling material has the same acoustic impedance as the human body, and the ultrasonic signal transmitted through it can reach the human body without being greatly attenuated and reflected, and can be flexibly deformed according to the shape of the body surface. It is. The acoustic coupling material (1) minimizes the change in acoustic impedance until the ultrasonic signal reaches the body surface from the ultrasonic probe, reduces signal loss due to reflection, and (2) is flexible. It is used for reasons such as to fit the shape of the body surface by the material and to reliably measure curved surfaces such as limbs. Since it has an acoustic impedance equivalent to that of the human body, soft tissue formed of a polymer gel or the like is suitable. In the exemplary system, Sonagel (manufactured by Takiron Co., Ltd.) was used in the form shown in FIG.

  Water is also suitable as a material having an acoustic impedance comparable to that of the human body. In this case, as shown in FIG. 4B, an inexpensive system can be configured by surrounding the body tissue immersed in the water tank with an ultrasonic probe. Also, considering the convenience during use, as shown in FIG. 4 (C), by pumping water into and out of a cuff used for blood pressure measurement etc., the size can be varied to some extent, It is also possible to configure a system that does not get wet with water.

(Probe switching part)
The probe switching unit performs switching between the vibration element in the ultrasonic probe and a voltage circuit that drives the vibration element. The exemplary system uses eight probes containing ultrasonic transducer elements and has one voltage circuit for driving them. These connections can be switched based on a command signal from a digital I / O board provided in the personal computer, and the first to eighth probes can be switched in order and arbitrarily. As a result, it is possible to measure images from a plurality of probes with a smaller number of image data measuring units.

[Image data measurement unit]
In the image data measuring unit, a signal from the probe selected by the probe switching device is captured as image data. In the case of commercially available ultrasonic diagnostic apparatuses, when outputting this image signal data to an external video, printer, personal computer or the like, it is generally taken out by down-converting it as a video signal or taking it out as still image data. However, this method is insufficient for performing high-speed image composition processing. This is because it takes about several seconds to capture video in a stable state while switching the images of the eight probes at the video signal refresh rate (30 Hz). In this exemplary system, image data in a state where no down-conversion is performed is transferred at high speed using a USB interface provided in the personal computer. Thus, the image data before down-conversion or the image data down-converted at a refresh rate faster than the normal video rate is output.

  When measuring an image of a body tissue, it is desirable that the change in density of the tissue image data to be noticed is visually easy to understand. An adjustment slider was prepared so that the brightness could be adjusted. The user can adjust these in real time while viewing the image data.

[Image data composition unit]
The image data synthesis unit can be configured by software on a personal computer, for example. In the exemplary system, the values of the angle sensors (encoders) on the fixture are acquired at the same time as the images of the fragments are acquired from a plurality of ultrasonic probes. An encoder board provided in a personal computer is used for capturing the angle. And the relative positional relationship of each image is calculated from the taken angle data, and the process which synthesize | combines them is implemented.

  During image synthesis, the user can select several synthesis methods via an interface on a personal computer. For example, when considering two images to overlap as shown in FIG. 5 (a), the overlapping part is calculated in advance as shown in (b), and the image is connected at the midpoint of the overlapping part. A method of comparing the pixels of the part, calculating the average value, and selecting the maximum / minimum value can be considered. These may be selected according to the properties of the image obtained from the tissue of interest.

  FIG. 6 is an example of image composition. This image is obtained by measuring the cross section of the thigh. The upper diagram shows a fragment image from each probe, and the lower diagram shows a composite image. It can be seen from this synthesis example that fat, muscle, fascia, bone, and the like can be observed.

[Moving image display section]
A series of processes consisting of probe switching, measurement of fragment images, and imaging of a tissue cross-sectional image by combining fragment images are repeated. The moving image display unit can repeatedly display the image data of the cross section synthesized by the image data synthesis unit, and present the obtained image to the user as a moving image. The moving image can also be recorded on a hard disk of a personal computer.

  The method, apparatus, and program for capturing a moving image of a cross-section of a body tissue using a plurality of ultrasonic probes according to the present invention do not require a large-scale apparatus such as MRI or CT, and are portable and used in a field. Therefore, the following industrial use can be expected because it can be measured as a moving image.

  Rehabilitation effect measurement, follow-up observation, etc. can be performed by measuring muscle cross-sectional areas in orthopedics, geriatric facilities, osteopaths, and warmers. By accumulating data at this time, it is possible to achieve age-based evaluation, physique-based evaluation, walking ability, and living limb strength evaluation.

  In professional, sports facilities, fitness clubs, sports medicine, etc., by observing muscle cross-sectional area, muscle quality, fat amount and balance of left and right, follow-up training, fatigue assessment, injury prediction, recovery assessment Etc. can be performed. Visual persuasion is also increased when providing educational guidance.

  In cosmetic surgery, esthetic salons, etc., by observing the cross-sectional area, muscle mass, the amount of fat and the balance between left and right, it is possible to determine diet effects, early detection and evaluation of rebound, prevention, etc. Can increase the persuasive effect of prescription.

System overview diagram Relationship diagram of probe outline and composite image Example of probe placement without fixture Example of acoustic coupling material Image composition method Example of composite image

Claims (30)

A plurality of ultrasonic probes capable of measuring ultrasonic B-mode images are fixed around the body tissue via an acoustic coupling material,
Select a probe for performing image measurement sequentially from the plurality of probes, sequentially measure a fragment image of the body tissue from the selected probe,
A plurality of sequentially measured fragment images are combined to synthesize a body tissue cross-sectional image,
A moving image photographing method for a cross-section of a body tissue using a plurality of ultrasonic probes for displaying a moving image by repeatedly displaying the synthesized images one after another. The ultrasonic probe has a measurable range in the depth direction of 10 cm or more, the focus position in the depth direction can be set arbitrarily, and the width of the measurable B-mode image is the width of the probe outer shape. The method for capturing a moving image of a cross-section of a body tissue using a plurality of ultrasonic probes according to claim 1, wherein the method is sufficiently wide. The ultrasonic probe is fixed by a link that fixes each probe and a joint that connects the links, and the joint can be attached and detached, and each joint is provided with an angle sensor. The method for measuring a moving image of a cross-section of a body tissue using a plurality of ultrasonic probes according to claim 1, wherein the geometrical relative position is measured. The acoustic coupling material has an acoustic impedance equivalent to that of the human body, and the ultrasonic signals transmitted through the acoustic coupling material can reach the human body without being greatly attenuated and reflected, and can be flexibly deformed according to the shape of the body surface. A method for capturing a moving image of a cross-section of a body tissue using a plurality of ultrasonic probes according to claim 1. The selection of the probe is performed by switching the connection between the probe and the image data measurement unit, and measuring images from a plurality of probes with a smaller number of image data measurement units. A method of capturing a moving image of a cross section of a body tissue using a plurality of ultrasonic probes. 2. The plurality of super images according to claim 1, wherein the measurement of the fragment images outputs image data before down-conversion or image data down-converted at a refresh rate faster than a normal video rate. A method for capturing a moving image of a cross-section of a body tissue using an acoustic probe. The moving image of a cross section of a body tissue using a plurality of ultrasonic probes according to claim 1, wherein the measurement of the fragment images is performed by adjusting contrast and brightness independently for each of the surface layer to the deep layer of the body tissue. Image shooting method. In the synthesis of the body tissue cross-sectional image, the measured fragment image is subjected to a process of superimposing based on the relative position information identified from the angle sensor, and at that time, for a portion where a plurality of images overlap, 2. The moving image photographing method of a body tissue cross section using a plurality of ultrasonic probes according to claim 1, wherein the whole image is synthesized by removing the portion in advance. The composition of the cross-sectional images of the body tissue is a value obtained by averaging the luminances of image pixels overlapping at the same position, or the maximum and minimum luminance values of the combined pixels when combining a plurality of images. A moving image photographing method of a body tissue cross section using a plurality of ultrasonic probes according to claim 1. The display of the moving image is characterized by repeating a series of processes consisting of probe selection, measurement of a fragment image, and imaging of a tissue cross-sectional image by combining fragment images, and displaying the obtained image as a moving image. A moving image photographing method of a cross-section of a body tissue using the plurality of ultrasonic probes according to 1. Multiple ultrasonic probes that can measure ultrasonic B-mode images, fixtures that fix them, acoustic coupling material that fills the space between the probe and body tissue, and any of the multiple probes A probe switching unit that selects whether to perform measurement, an image data measurement unit that measures a fragment image of a body tissue from a probe, an image data synthesis unit that combines a fragment image and synthesizes a body tissue cross-sectional image, A moving image photographing apparatus for cross-section of a body tissue using a plurality of ultrasonic probes composed of a moving image display unit that displays a moving image by continuously displaying synthesized images one after another. The ultrasonic probe has a measurable range in the depth direction of 10 cm or more, the focus position in the depth direction can be set arbitrarily, and the width of the measurable B-mode image is the width of the probe outer shape. The moving image photographing apparatus for cross-section of a body tissue using a plurality of ultrasonic probes according to claim 11, wherein the apparatus is sufficiently wide. The fixture comprises a link that fixes each probe and a joint connecting the links, and the joint is detachable, so that the entire size can be freely adjusted, and the joint is provided with an angle sensor, 12. The moving image photographing apparatus of a body tissue cross section using a plurality of ultrasonic probes according to claim 11, wherein a geometric relative position of each probe is measured. The acoustic coupling material has an acoustic impedance equivalent to that of the human body, and the ultrasonic signals transmitted through the acoustic coupling material can reach the human body without being greatly attenuated and reflected, and can be flexibly deformed according to the shape of the body surface. A moving image photographing apparatus for cross-section of a body tissue using a plurality of ultrasonic probes according to claim 11. The probe switching unit switches the connection between the probe and the image data measurement unit arbitrarily at high speed, and measures images from a plurality of probes with a smaller number of image data measurement units. A moving image photographing apparatus for cross-section of a body tissue using the plurality of ultrasonic probes according to 11. In the image data measurement unit, in order to observe images from a plurality of probes at a high speed, not the analog video signal after down-conversion but the image data before down-conversion or a refresh rate faster than the normal video rate. The moving image photographing apparatus for cross-section of a body tissue using a plurality of ultrasonic probes according to claim 11, further comprising an interface capable of outputting image data subjected to down-conversion. 12. The image data measurement unit according to claim 11, wherein contrast and brightness are adjusted independently for each of the surface layer to the deep layer of the body tissue in order to measure the body tissue of interest as a clear image. A moving image photographing apparatus for cross-section of body tissue using a plurality of ultrasonic probes. The image data synthesis unit performs a process of superimposing the fragment images measured by the image data measurement unit based on relative position information identified from an angle sensor provided in a fixture, and at that time, a plurality of images The moving image photographing apparatus for cross-section of a body tissue using a plurality of ultrasonic probes according to claim 11, wherein the portions where the images overlap are removed in advance and the whole image is synthesized. The image data synthesizing unit, regarding the synthesis when a plurality of images overlap, sets the averaged luminance of image pixels overlapping at the same position, or the maximum and minimum luminance values as the luminance of the pixel after synthesis. A moving image photographing apparatus for a body tissue cross section using a plurality of ultrasonic probes according to claim 11. The moving image display unit repeats a series of processing including probe switching, measurement of fragment images, and imaging of a tissue cross-sectional image by combining fragment images, and displays the obtained image as a moving image. Item 12. A moving image photographing device for a cross-section of a body tissue using the plurality of ultrasonic probes according to Item 11. A plurality of ultrasonic probes capable of measuring ultrasonic B-mode images are fixed around the body tissue via an acoustic coupling material,
Select a probe for performing image measurement sequentially from the plurality of probes, sequentially measure a fragment image of the body tissue from the selected probe,
A plurality of sequentially measured fragment images are combined to synthesize a body tissue cross-sectional image,
Display the video by repeating this synthesized image one by one and displaying it continuously.
A moving image photographing program of a body tissue cross section using a plurality of ultrasonic probes for executing each procedure. The ultrasonic probe has a measurable range in the depth direction of 10 cm or more, the focus position in the depth direction can be set arbitrarily, and the width of the measurable B-mode image is the width of the probe outer shape. The moving image photographing program for a body tissue cross section using a plurality of ultrasonic probes according to claim 21, wherein the moving image photographing program is sufficiently wide. The ultrasonic probe is fixed by a link for fixing each probe and a joint connecting the links, and the joint can be attached and detached, and each joint is provided with an angle sensor. 23. The moving image photographing program for a body tissue cross section using a plurality of ultrasonic probes according to claim 21, wherein the geometric relative position of the body is measured. The acoustic coupling material has an acoustic impedance equivalent to that of the human body, and the ultrasonic signals transmitted through the acoustic coupling material can reach the human body without being greatly attenuated and reflected, and can be flexibly deformed according to the shape of the body surface. A moving image photographing program of a body tissue cross section using a plurality of ultrasonic probes according to claim 21. The selection of the probe includes switching the connection between the probe and the image data measurement unit, and measuring images from a plurality of probes with a smaller number of image data measurement units. A moving image photographing program for a cross section of body tissue using a plurality of ultrasonic probes. The plurality of super images according to claim 21, wherein the measurement of the fragment images outputs image data before down-conversion or image data down-converted at a refresh rate faster than a normal video rate. A moving image photographing program of a body tissue cross section using an acoustic probe. The moving image of a cross section of a body tissue using a plurality of ultrasonic probes according to claim 21, wherein the measurement of the fragment images is performed by adjusting contrast and brightness independently for each of the surface layer to the deep layer of the body tissue. Image shooting program. In the synthesis of the body tissue cross-sectional image, the measured fragment image is subjected to a process of superimposing based on the relative position information identified from the angle sensor, and at that time, for a portion where a plurality of images overlap, The moving image photographing program for a body tissue cross section using a plurality of ultrasonic probes according to claim 21, wherein the whole image is synthesized by removing the portion in advance. The composition of the cross-sectional images of the body tissue is a value obtained by averaging the luminances of image pixels overlapping at the same position, or the maximum and minimum luminance values of the combined pixels when combining a plurality of images. The moving image photographing program of a body tissue cross section using a plurality of ultrasonic probes according to claim 21. The display of the moving image is characterized by repeating a series of processes consisting of probe selection, measurement of a fragment image, and imaging of a tissue cross-sectional image by combining fragment images, and displaying the obtained image as a moving image. A moving image photographing program of a body tissue cross section using the plurality of ultrasonic probes according to 21.

Images