JP4729706B2 - Correction device - Google Patents

Description

  The present invention relates to a correction apparatus that corrects measurement data of a medical ultrasonic apparatus using an ultrasonic diagnostic phantom.

  Currently, high-frequency (ultrasound) is transmitted to the human body that is the subject, and converted into an image based on the intensity, frequency, and time of the reflected wave (echo) that bounces off the internal organs of the human body. Medical ultrasonic measurement devices (hereinafter simply referred to as “ultrasonic devices”) for confirming the state of internal organs, tissues, fetuses, etc. are widely used.

  This ultrasonic apparatus has an ultrasonic image display main body (hereinafter referred to as a monitor) and an operation unit capable of selecting / adjusting ultrasonic waves having a frequency and a gain in a predetermined range, and a human body. And a probe for receiving an echo that has rebounded in a predetermined area inside the subject, and the echo received by the probe is converted into an image by the main body of the ultrasonic device. Displayed on the monitor. The measurer can observe and measure the internal state of the human body through the monitor while relatively moving the probe and the human body surface by placing the probe on the surface of the subject.

  In the ultrasonic device, the ultrasonic wave emitted from the probe has directivity, and the ultrasonic wave emitted from the probe according to the position of the organ in the human body (distance between the probe tip and the target object) to be confirmed. The frequency, gain, etc. must be adjusted as appropriate, and considerable experience is required in using the ultrasonic apparatus.

For this reason, the ultrasonic phantom is known as an ultrasonic human body model that exhibits the same response to ultrasonic waves as human body organs and tissues for training for beginners who use ultrasonic devices and for calibration of ultrasonic devices. (Patent Document 1).
JP 2005-118187 A

  The medical phantom described in Patent Document 1 can extract the shape and position of a human organ and the like with high accuracy and can be used effectively as training for ultrasonic measurement, but it simulates a general organ shape of a human body. For example, when there is an abnormality such as a tumor in an organ, the judgment of how large it is is left to the experience of the measurer.

  In particular, there is carotid ultrasound measurement as one of the measurements using ultrasound on the human body. This is because the carotid artery (consisting of a single common carotid artery, bifurcated internal carotid artery and external carotid artery) passing through the left and right sides of the human neck as shown in FIG. The inner and middle thicknesses, the size of plaque formed on the inner wall of the blood vessel, and the blood vessel diameter are measured by an ultrasonic device. This carotid ultrasound measurement enables screening for arteriosclerotic diseases, cerebrovascular diseases such as cerebral infarction, and cervical vascular diseases such as carotid artery stenosis. It is.

  However, it is not easy to measure the thickness and diameter of the vascular wall (inner media thickness) of the carotid artery. If the frequency or gain of the ultrasonic device is changed, the vascular wall (inner media thickness) displayed on the monitor ) And the blood vessel diameter are different, and it is difficult to perform accurate measurement. In addition, there are other types of ultrasonic devices used in medical institutions and the like, and the performance is not necessarily common, so it is necessary to consider so-called habits for each ultrasonic device.

  In view of the above problems, the present invention uses the shape data and the carotid artery phantom created from the data as an index, so that an error from the measurement data regardless of the measurement setting conditions such as the performance of the ultrasonic device and the gain ( An object of the present invention is to provide a correction device that calculates a correction value for correcting (difference).

  In order to solve the above-described problems, the invention of claim 1 stores a carotid artery phantom, which is an artificial carotid artery model having diseased sites with different medial thickness, plaque size, artery diameter, etc., and shape data of the carotid artery phantom Shape data storage means, measurement data acquisition means for acquiring measurement data obtained by measuring the carotid artery phantom as an image by a medical ultrasonic device, and carotid artery of a diseased part corresponding to the measurement data acquired by the measurement data acquisition means Shape data extraction means for extracting phantom shape data as partial shape data from the shape data storage means, and correction value calculation means for calculating a correction value for the measurement data based on the extracted partial shape data. The gist of the present invention is a correction device characterized by the above.

By using this correction device, a correction value for the measurement data of the ultrasonic device can be obtained based on the measurement data and shape data of the carotid artery phantom.
The invention according to claim 2 is characterized by comprising actual data correction means for correcting actual data of the carotid artery of the subject obtained by the ultrasonic measurement device based on the correction value. As a result, it is possible to correct the actual measurement data when the subject is measured by the ultrasonic apparatus based on the correction value, and to reduce the measurement error.

  According to a third aspect of the present invention, there is provided a moving device that relatively moves the carotid artery phantom and the probe of the ultrasonic device. This eliminates the need for the measurer to hold the probe and move it relative to the carotid artery phantom, thereby facilitating the calculation of the correction value.

  According to a fourth aspect of the present invention, the moving device moves the carotid artery phantom on the same trajectory as the movement trajectory of the neck accompanying relative rotation or relative movement of the subject relative to the carotid artery with the probe of the ultrasonic device fixed. It is characterized by being rotated or fed. As a result, the correction value can be calculated under the same environment as the actual ultrasonic carotid artery measurement.

  In the invention of claim 5, the carotid artery phantom is formed so that a reference point for associating the measurement data acquired by the measurement data acquisition means with the position of the carotid artery phantom can be read by an ultrasonic device. And This makes it possible to relate the shape or the like of the diseased part to the angle or length from the reference point, and the position can be easily identified.

  According to a sixth aspect of the present invention, a plaque phantom, which is a diseased part, is formed in the carotid artery phantom in the carotid phantom, and the plaque phantom has various shapes. This makes it possible to calculate plaque correction values for various shapes as well as the basic shape having a semicircular cross section.

  In the invention of claim 7, the plaque phantom has ultrasonic characteristics equivalent to the plaque of the subject in measurement by an ultrasonic device by distributing or mixing metal powder, rubber, polymer powder, or oily liquid inside. It is characterized by comprising. Thereby, it is possible to calculate plaque correction values relating to various properties such that the inside is calcified or bleeding.

  The invention according to claim 8 is characterized in that the plaque phantom is integrally formed with the carotid artery phantom with respect to the inner peripheral surface of the carotid artery phantom. Thereby, the plaque phantom can be simultaneously formed of the same material as the intima, and the manufacture of the carotid artery phantom is facilitated.

  In the invention of claim 9, the carotid artery phantom has a cylindrical shape, and disease sites having different medial thickness, plaque size, artery diameter, and the like are formed on the inner peripheral surface at equal intervals, and each disease site Is characterized in that the state of the disease changes along the axial direction of the carotid artery phantom. As a result, when acquiring the measurement data of the carotid artery phantom, after determining the angle of the carotid artery phantom, the carotid artery phantom can be fed and moved only in the axial direction to facilitate control.

  The invention of claim 10 is characterized in that the measurement data acquisition means acquires a plurality of patterns of measurement data with different operating frequencies and gains of the ultrasonic apparatus. Accordingly, even when measurement is performed by selecting a frequency or a gain when using the ultrasonic apparatus, a correction value corresponding to the selected frequency or gain can be obtained.

  According to the present invention, it is possible to calculate a correction value for correcting an error (difference) from measurement data regardless of measurement and measurement conditions such as the performance and gain of the ultrasonic apparatus, and the measurement is performed in the measurement of the carotid artery for the subject. The error can be corrected.

Hereinafter, an embodiment of a correction apparatus for an ultrasonic apparatus embodying the present invention will be described with reference to FIGS.
FIG. 1 is a conceptual diagram of a correction apparatus according to an embodiment of the present invention. The correction device 1 includes a computer 2 and a phantom unit 3 electrically connected to the computer 2 via a communication line. The correction device 1 is also electrically connected to the ultrasonic device 4 via a communication line. The phantom unit 3 includes a carotid phantom 5 and a rectangular body 6 for fixing the probe 41 of the ultrasonic device 4 and a carotid phantom, as shown in FIG. And a driving device 7 as a moving device for rotating 5 (meaning rotation in the circumferential direction of the neck) and feeding movement (meaning movement in the axial direction of the neck).

  The carotid artery phantom 5 is a carotid artery model for ultrasonic measurement in which a portion to be measured with ultrasonic waves is artificially formed in the carotid artery running on the left and right of the neck of the human body. As shown, the shape is simplified and the outer shape is formed as a cylindrical shape. The carotid artery phantom 5 is made of a material having ultrasonic characteristics that are the same as or similar to those of the human carotid artery with respect to ultrasonic waves. Specifically, it is made of agar, gelatin, natural rubber or other polymer gel. It is used as.

  It should be noted that the marker 8 is embedded in at least one end of the carotid artery phantom 5 by using a marker 8 made of a fine member that clearly differs in ultrasonic characteristics from the material used for the carotid artery phantom 5. The driving start position (reference point) at the time of rotation and feed movement can be obtained.

  That is, by setting a predetermined position that the marker 8 can capture with ultrasound as the driving start position of the carotid artery phantom 5, the state of the carotid artery phantom is associated with the rotation angle from the driving start position and the length of the feed movement. Can be calculated more accurately. Although not shown, a plurality of markers having different ultrasonic characteristics can be embedded in the carotid artery phantom so that any marker corresponding to the purpose of use can be set as the drive start position.

The carotid artery phantom 5 is formed as a three-layer structure of an outer membrane 51, a middle membrane 52, and an inner membrane 53 from the outside like the blood vessel wall in the carotid artery site, as shown in a sectional view in FIG. 4.
In the carotid artery phantom 5, a disease site to be measured in the ultrasonic device 4 is formed. Specifically, the diseased site is a site where an intima-media thickness (also referred to as IMT) 54 that is the thickness of the media and intima of the blood vessel is displaced (this portion is referred to as “inner-media thickness displacement site”). 55, a portion where various plaque phantoms P1 to P6 formed in the inner membrane are formed (this portion is referred to as “plaque phantom formation portion”) 56, a portion where the inner diameter between the vascular intima is displaced (this portion is referred to as “ This is referred to as a “stenosis displacement site”.

  The inner-medial thickness displacement portion 55 is formed along the longitudinal direction at a part of the circumferential direction of the cylindrical carotid artery phantom 5 (at 4 o'clock in FIG. 4), as shown in FIG. 5a. In addition, the inner-media thickness change portion 55 is formed so that the inner-media thickness is sequentially displaced along the longitudinal direction of the carotid artery phantom. In the measurement using the ultrasonic device 4, the three layers of the outer membrane 51, the inner membrane 52, and the inner membrane 53 can be grasped as images of relatively high luminance, low luminance, and high luminance from the outside, respectively. In creating the arterial phantom 5, it is necessary to select a material in consideration of the relative difference in the brightness of the three-layer structure of the outer membrane 51, the middle membrane 52 and the inner membrane 53.

  Next, the plaque phantom formation part 56 is a part of the carotid artery phantom 5 in the circumferential direction (the part where the angle is different from the inner-media thickness displacement part 55 in the circumferential direction. At the time position) along the longitudinal direction. As shown in FIG. 5 b, the plaque phantom formation site 56 has a plurality of plaque phantoms having different shapes and sizes on the inner peripheral surface (surface on the blood flow side) of the intima along the longitudinal direction of the carotid artery phantom 5. P1 to P6 are formed.

  In ultrasonic measurement, the height of a plaque (in the case of simply “plaque” means a plaque as an actual disease) is measured as a height including the inner-media thickness, and the height is 1.1 mm. The above is the standard for ultrasonic screening. For this reason, when the plaque phantom P1 and the like are formed, it is necessary to set the height including the inner and middle film thicknesses on the basis of 1.1 mm. Many plaques formed in the carotid artery are deformed. For this reason, in addition to the plaque phantoms P1 and P3 having the basic shape, the plaque phantom P2 whose inside is calcified, the plaque phantom P4 in which a depression is formed due to internal destruction, the plaque phantom P5 whose inside is bleeding, an arc shape, etc. Many types of plaques such as a plaque phantom P6 that rises and then changes its height linearly are formed.

  In addition, the plaque formed in the carotid artery is basically as bright as the intima, so the plaques phantoms P1 to P6 basically have the same luminance. Depending on the cause, the luminance rate is not necessarily the same as that of the inner membrane. For example, when there is internal bleeding inside the plaque, the brightness may be different if the plaque is calcified locally or entirely. In the corresponding plaque phantom (P2, P5), in the former, a polymer powder, oily liquid or liquid such as distilled water is encapsulated in the plaque phantom P2, and in the latter, a fine metal powder is contained in the plaque phantom P5. It is possible to obtain the ultrasonic characteristics similar to an actual plaque by adjusting the brightness by mixing locally or entirely.

  Further, the stenosis displacement portion 57 is a part of the carotid artery phantom 5 in the circumferential direction (a portion where the angle is further different from the inner-media thickness displacement portion 55 and the plaque phantom formation portion 56 in the circumferential direction, in FIG. At 8 o'clock) in the longitudinal direction. As shown in FIG. 5 c, the stenosis displacement portion 57 is formed by integrally thickening the inner surface of the blood vessel along the longitudinal direction of the carotid artery phantom 5, and a stenosis portion 59 having a narrow lumen is formed integrally with the intima 53. The stenosis means that cholesterol or the like adheres to the inner wall of the carotid artery and causes arteriosclerosis. However, the carotid artery phantom 5 of the present embodiment has ultrasonic characteristics equivalent to cholesterol on the intima 53. It is also possible to form the constricted portion 59 by pasting a material having the same.

  Since the carotid artery ultrasonic measurement on the subject is based on measuring the blood vessel wall portion farther from the probe 41 in the blood vessel wall, the same applies to the ultrasonic measurement using the carotid artery phantom 5. It is preferable to use a technique. In this case, the inner-medium-thickness displacement portion 55, the plaque phantom formation portion 56, and the stenosis displacement portion 57 formed along the axial direction at locations where the angles of the carotid artery phantom 5 are varied in the circumferential direction are 120 in the circumferential direction. By forming them at different degrees and angles, mutual interference can be minimized during ultrasonic measurement (FIG. 4).

  The carotid artery phantom 5 having the structure described above is immersed in a rectangular body 6 filled with water (distilled water) 61, and can be rotated and moved in the longitudinal direction by a driving device 7 (FIG. 2). The carotid artery phantom 5 is immersed in water 61 because the human carotid artery is present in a plurality of tissues such as cervical skin and muscle, and the measurement by the ultrasonic device 4 is performed by placing the probe 41 on the cervical skin surface. This is because it is necessary to form an environment equivalent to this because the measurement is applied. Here, since water is mentioned as a substance having ultrasonic characteristics similar to that of human internal tissue, water 61 is interposed between the probe 41 and the carotid artery phantom 5.

  In the rectangular body 6, the upper portion of the water 61 is covered with a skin phantom 62 made of a natural rubber sheet having a thickness of about 1 to 3 mm. The reason for using natural rubber as the skin phantom 62 on the surface is that the ultrasonic characteristics (sound speed) are equivalent to those of living soft tissues such as human skin. In particular, since the neck becomes thicker toward the head, it is preferable to form an inclination so that the direction of the skin phantom 62 located on the head (left side in FIG. 2) is slightly higher. A probe fixing means 63 for fixing the probe 41 at a position where ultrasonic waves are transmitted toward the carotid artery phantom 5 is provided on the upper portion of the rectangular body 6. The probe fixing means 63 means a structure that can be fixed with the tip of the probe 41 in contact with the skin phantom 62 so as to be substantially perpendicular.

  The relationship between the carotid artery phantom 5, the water 61 and the skin phantom 62 in the rectangular body 6 arranged in this way corresponds to the carotid artery, internal skin tissue and skin in the human body neck. Therefore, the distance from the probe 41 to the carotid artery phantom 5 needs to be set equal to the distance from the neck skin (position to which the probe 41 is applied) to the carotid artery in the human body. In addition, the carotid artery phantom 5 is configured to be able to rotate and feed within a rectangular body 6 by a driving device 7. This reproduces a technique for measuring a necessary portion of the carotid artery by applying the probe 41 to the human neck in the ultrasonic measurement and then relatively moving the probe 41 and the neck in the circumferential direction and the longitudinal direction. Accordingly, the probe 41 and the carotid artery phantom 5 can be moved relative to each other.

  The drive device 7 includes a first drive motor 71 and a second drive motor 72 that can be numerically controlled, and a transmission mechanism (not shown) that transmits the rotation of each drive motor to the carotid artery phantom 5 as a rotation or feed movement. . The first drive motor 71 can rotate the carotid artery phantom 5 in the circumferential direction, and the second drive motor 72 can feed and move the carotid artery phantom 5 along its longitudinal direction. The type and configuration of the transmission mechanism that transmits the rotation of each drive motor to the rotation or feed movement of the carotid artery phantom 5 is not limited, and the first drive motor 71 and the second drive motor 72 are driven simultaneously to drive the carotid artery phantom. It is also possible to perform 5 rotations and feed movements simultaneously. Each drive motor is a pulse motor that is numerically controlled by the computer 2.

  The computer 2 constituting the correction apparatus 1 includes a phantom drive control means 21, a shape data storage means 22, a measurement data acquisition means 23, a shape data extraction means 24, a correction value calculation means 25, and an actual data correction means 26. And.

  The phantom drive control means 21 is means for sending drive signals to the first drive motor 71 and the second drive motor 72 in order to rotate and feed the carotid artery phantom 5, and is a ROM (not shown) in which a predetermined drive program is stored. ) Is connected. The drive program moves the carotid phantom 5 to a predetermined drive start position as the correction apparatus 1 is activated. Further, the driving program sets the carotid artery phantom 5 so that the inner-media thickness displacement part 55, the plaque phantom formation part 56, and the stenosis displacement part 57 in the carotid artery phantom 5 can be measured in order by the ultrasonic device 4. The first drive motor 71 and the second drive motor 72 are set to be driven to rotate and feed.

  The shape data storage means 22 has a shape database 221. In the shape database 221, the medial thickness 54 of the medial thickness change part 55 in the carotid artery phantom 5, the size (height) of the plaque phantom P 1 formed in the plaque phantom formation part 56, etc. The shape data 222 that associates the diameter of the artery based on the longitudinal position of the carotid artery phantom 5 is stored (FIG. 7). The shape data 222 of the shape database 221 is data serving as a reference when correcting the measurement result by the ultrasonic device 4. Although the shape database 221 is blank in the drawing, a numerical value created based on CAD data serving as a design drawing when the carotid artery phantom 5 is manufactured may be stored.

  Moreover, it is preferable that the shape database 221 is recorded as continuous data regarding the respective parts of the carotid artery phantom 5. However, when the measurement location for the carotid artery phantom 5 is determined in advance, for example, when the measurement location is set to 5 locations in the inner-media thickness displacement portion 55, the measurement is performed in a spot manner. The shape data 222 for only the measurement site may be recorded in the shape database 221.

  The measurement data acquisition means 23 refers to the inner and middle film thicknesses 54, the size of the plaque phantom P1, etc. based on the image data obtained by measuring the carotid artery phantom 5 using the ultrasonic device 4 to be corrected, the stenosis site 59 is a means for obtaining each measurement data of the arterial diameter based on 59. The measurement data acquisition means 23 has a measurement data file 231 (FIG. 8). Measurement data 232 relating to the medial thickness 54 of the carotid artery phantom 5, the size of the plaque phantom P1, etc., and the artery diameter based on the stenotic site 59 are stored. It can be stored in association with the position of the carotid artery phantom 5. When a plurality of types with different frequencies and gains can be selected for measurement by the ultrasonic device 4, the number of measurement data files (231a, 231b, 231n) corresponding to the types is provided.

  In the correction device 1, measurement data 232 relating to the medial thickness 54 of the carotid artery phantom 5, the size of the plaque phantom P 1 and the like, and the diameter of the artery based on the stenotic site 59 are displayed on a monitor (illustrated). Image data (B-mode image) displayed on (not) is obtained via an external output of the ultrasonic apparatus 4. The image data can be obtained by automatic calculation by processing the image data in the computer 2 based on image processing software installed in the computer 2 in advance. The measurement data acquisition means 23 can also acquire the measurement data 232 continuously during the feeding movement of the carotid artery phantom 5, but the measurement location for the carotid artery phantom 5 is determined in advance as described above. The measurement data 232 at the predetermined position can also be obtained.

  The shape data extraction means 24 is obtained by the measurement data acquisition means 23 from the shape data 222 of inner media thickness, plaque phantom size, and arterial diameter stored in the shape database 221 of the shape data storage means 22. It is a means for extracting each data of inner media thickness, plaque size, and artery diameter at a position corresponding to each measurement data 232. The shape data extraction unit 24 specifies the part and position of the carotid artery phantom 5 measured by the probe 41 of the ultrasonic device 4 based on the control signal from the phantom drive control unit 21, and the shape data 222 is extracted from the shape data 222. Shape data at a specific part and position is extracted.

  The shape data extraction means 24 has an extraction data file 241 (FIG. 11). The extracted shape data relating to the inner media thickness, plaque phantom size, and artery diameter is associated with the position of the carotid artery phantom as partial shape data 242. The extracted data file 241 is stored.

  The correction value calculation means 25 compares the measurement data 232 of the specific part of the carotid artery phantom 5 acquired by the measurement data acquisition means 23 with the partial shape data 242 extracted by the shape data extraction means 24 for the corresponding part. Based on the partial shape data 242, a necessary correction value for the measurement data 232 is calculated.

  That is, since the measurement data 232 of the carotid artery phantom 5 acquired by the measurement data acquisition unit 23 and the partial shape data 242 extracted by the shape data extraction unit 24 are data of the same part and position in the carotid artery phantom 5, theoretically. Should match. However, there are many cases where the two data do not match depending on the overall performance including the processing capability and resolution of the ultrasonic apparatus and the type of frequency and gain selected. Therefore, the correction value calculation means 25 uses the partial shape data 242 extracted by the shape data extraction means 24 as a reference value, and the measurement data 232 of the specific part and position of the carotid phantom 5 acquired by the measurement data acquisition means 23 is the reference data. A correction value for matching the value is calculated.

  In the calculation of the correction value by the correction value calculation means 25, each of the inner-media thickness displacement portion 55, the plaque phantom formation portion 56, and the stenosis displacement portion 57, that is, the correction value of the inner-media thickness 54, the plaque phantom P1, etc. The correction value for the size of the artery and the correction value for the artery diameter based on the stenotic region 59 are calculated. The correction value may be a correction value that can be collectively applied to the inner / thickness displacement portion 55, for example, and if the error is large between a thin thickness and a thick thickness, The correction value may be set individually by dividing the film thickness into several thickness categories. The same applies to the size of the plaque phantom P1 and the like and the stenosis region 59. Further, the correction value may be an addition / subtraction value that is a difference between the measurement data 232 and the partial shape data 242, a coefficient value that is a ratio between the measurement data 232 and the partial shape data 242, or a predetermined arithmetic expression. Good.

  The correction value calculation means 25 has a correction value data file 251. After calculating the correction values of the inner media thickness, the plaque phantom size, and the arterial diameter, the correction value is associated with the position of the carotid artery phantom. The correction value data 252 is stored in the correction value data file 251. Further, when there are a plurality of types of measurement by the ultrasonic device 4 with different frequencies and gains, the number of correction value data files (251a, 251b, 251n) corresponding to the types is provided.

  The actual measurement data correction means 26 corrects the measurement results of the inner media thickness, plaque size, and arterial diameter of the subject with respect to the carotid artery based on the correction value calculated by the correction value calculation means 25. The actual measurement data correcting means 26 has an actual measurement data file 261 (FIG. 11). The actual measurement data correcting means 26 stores the data obtained by measuring the inner media thickness, the plaque size, and the artery diameter of the subject by the ultrasonic device 4 as the actual measurement data 262 in association with the frequency and the gain in the actual measurement data file 261. . Further, a correction value at a corresponding frequency and gain is extracted from the correction value data 252 of the correction value data file 251 and stored as a correction value 263 in the actual measurement data file 261. The actual measurement data correcting means 26 corrects the actual measurement data 262 based on the correction value 263, and stores the corrected data in the actual measurement data file 261 as the corrected actual measurement data 264.

  Hereinafter, a correction value calculation flow of the ultrasonic apparatus 4 using the correction apparatus 1 of the above embodiment will be described. This correction value calculation flow is roughly divided into a measurement step (S1) for measuring a carotid artery phantom, an extraction step (S2) for extracting shape data corresponding to the measurement result, and a calculation step (S3) for calculating a correction value. (FIG. 12a).

  The ultrasonic device 4 to be corrected has a general structure including an ultrasonic device main body provided with a monitor, and a probe 41 that transmits ultrasonic waves having a frequency and a gain in a predetermined range and receives the echoes. It shall be. The correction device 1 is electrically connected to the ultrasonic device 4 via a communication line, and can acquire image data converted by the ultrasonic device 4 based on the echo received by the probe 41. Hereinafter, a specific procedure for calculating a correction value using the carotid artery phantom 5 in the ultrasonic apparatus 4 will be described.

  First, as a previous step, the probe 41 of the ultrasonic device 4 is fixed to the probe fixing means 63 of the phantom unit 3, and the tip of the probe 41 is fixed so as to be applied to the skin phantom 62. At this time, an ultrasonic gel used for ultrasonic measurement on the human body is applied on the skin phantom 62 so that the ultrasonic wave transmitted from the probe 41 is reliably transmitted to the carotid artery phantom 5.

  In addition, the carotid artery phantom 5 is positioned at a predetermined driving start position by the driving device 7. The driving start position of the carotid artery phantom 5 may be any position, but preferably the carotid phantom 5 is set by setting the marker 8 embedded in the carotid artery phantom 5 as the driving start position. Whether it is in the initial position can be recognized via the ultrasonic device 4. The movement of the driving start position of the carotid artery phantom 5 is preferably automatically set by a driving program. Furthermore, a program may be set so that the carotid artery phantom 5 returns to the driving start position again after the series of driving operations of the carotid artery phantom 5 by the driving device 7 is completed.

  The correction value is calculated using the frequency and gain that are normally used by the ultrasonic apparatus 4 to be corrected. That is, if the frequency used in a certain ultrasonic apparatus 4 is 3 patterns of 5 MHz, 8 MHz, and 10 MHz and the gain is 2 patterns of large and small, the frequency pattern (3 patterns) × gain pattern (2 Measurement is performed with a total of six patterns. This is because, depending on the location of the carotid artery and the like, sufficient resolution cannot be obtained with a specific frequency and gain.

  The measurement step (S1) includes an inner / media thickness measurement step (S10) for measuring the inner / media thickness of the carotid artery phantom 5 and a plaque phantom measurement step (S11) for measuring the plaque phantom P1 and the like in the carotid artery phantom 5 The stenosis part measurement step (S12) is performed to measure the stenosis part 59 in the carotid artery phantom 5 (FIG. 12b).

  First, an inner / medium film thickness measurement step (S10) is performed. In this step, the phantom drive control means 21 is positioned so that the carotid artery phantom 5 is farthest from the predetermined drive start position with respect to the first drive motor 71 when the medial-medial thickness displacement portion 55 is farthest from the probe 41 side. The first drive motor 71 rotates the carotid artery phantom 5 in the circumferential direction based on the instruction (S101). When the rotation of the carotid phantom 5 by the first drive motor 71 is completed, the phantom drive control means 21 instructs the second drive motor 72 to send and move the carotid phantom 5, and the second drive motor 72 Based on this instruction, the feeding movement of the carotid artery phantom 5 is started (S102).

  Simultaneously with the start of the feed movement by the second drive motor 72, the measurement data acquisition means 23 starts measuring the inner-thickness film 54. The measurement data acquisition means 23 sequentially stores the measurement results in the measurement data file 231 while automatically measuring the inner-media thickness at predetermined intervals (time or feed length) (S103). When the other end of the phantom 5 is reached, the inner-medium film thickness measurement step ends (S104), and then the plaque phantom measurement step (S11) follows.

  In this plaque phantom measurement step (S11), the phantom drive control means 21 rotates the carotid artery phantom 5 with respect to the first drive motor 71 so that the plaque phantom formation site 56 is farthest from the probe 41 side. The first drive motor 71 rotates the carotid artery phantom 5 in the circumferential direction based on the instruction (S111).

  When the rotation of the carotid artery phantom 5 is completed, the phantom drive control means 21 instructs the second drive motor 72 to feed and move the carotid artery phantom 5, and the second drive motor 72 based on this instruction The feeding movement of the arterial phantom 5 is started (S112). Note that the direction of this feed movement may be the reverse of the feed movement in the inner-medium film thickness measurement step (S10), which is the previous step.

  Simultaneously with the start of the feed movement by the second drive motor 72, the measurement data acquisition means 23 starts measuring the plaque phantom P1 and the like. The measurement data acquisition means 23 sequentially stores the measurement results in the measurement data file 231 while automatically measuring the size of the plaque phantom P1 or the like (S113), and when the feed movement reaches one end of the carotid artery phantom 5, the plaque phantom The measurement step ends (S114), and then the stenosis site measurement step (S12). In this stenosis site measurement step (S 12), the phantom drive control means 21 makes the carotid artery phantom such that the stenosis displacement site 57 of the carotid artery phantom 5 is farthest from the probe 41 side with respect to the first drive motor 71. The first drive motor 71 rotates the carotid artery phantom 5 in the circumferential direction based on the instruction (S121).

  When the rotation of the carotid artery phantom 5 is completed, the phantom drive control means 21 instructs the second drive motor 72 to send and move the carotid artery phantom 5, and the second drive motor 72 performs the neck movement based on the instruction. The feeding movement of the arterial phantom 5 is started (S122). This feeding direction may be the direction opposite to the feeding direction of the plaque phantom measurement step (S11) which is the previous step (the inner and middle film thickness measurement step (S10) and the forward direction).

  Simultaneously with the start of the feed movement by the second drive motor 72, the measurement data acquisition means 23 starts measuring the stenosis site 59. The measurement data acquisition means 23 sequentially stores the measurement results in the measurement data file 231 while automatically measuring the inner diameter of the blood vessel at predetermined intervals (time or feed length) (S123). When the other end is reached, the stenosis site measurement step ends (S124), and the measurement step (S1) ends (END). As described above, when there are a plurality of frequencies and gains that are normally used by the ultrasonic apparatus to be corrected, the above steps are repeated for the number corresponding to the type.

  In the extraction step (S2), the shape data extraction means 24 uses the shape data 222 of the shape database 221 to determine the inner and middle film thicknesses, plaque phantoms, and stenosis sites corresponding to the site and position measured in the measurement step (S1). Data is extracted (S21). Subsequently, the extracted data is stored in the extracted data file 241 as partial shape data 242 (S22), and the extraction step (S2) is terminated (FIG. 2c).

  In the subsequent calculation step (S3), the correction value calculation means 25 performs each disease site and position on the basis of the partial shape data 242 stored in the extraction data file 241 and the measurement data 232 stored in the measurement data file 231. Then, the difference between the two is calculated, and a correction value is calculated as a value that offsets the difference (S31). The calculated correction value is stored as correction value data 252 in association with the position in the correction value data file 251 (S32), and the calculation step (S3) is terminated (FIG. 2d).

  By the above steps (S1, S2, S3), it is possible to obtain a correction value for correcting the measurement error of the measurement data regarding the diseased part when the carotid artery phantom 5 is measured by the ultrasonic device 4. Next, a measurement value correction flow when measuring the medial thickness of the subject's carotid artery using the correction value calculated above will be described. The flow includes an actual measurement step (S41), an approximate data selection step (S42), a correction value extraction step (S43), and a correction value calculation step (S44) (FIG. 2e). The measurer selects a predetermined frequency and gain using the ultrasonic device 4 that can use the correction value data 252, and then measures the medial thickness of the subject's carotid artery. The measurement result is stored as the actual measurement data 262 in the actual measurement data file 261 together with the used frequency and gain by the actual measurement data correcting means 26 (S41).

  Further, the actual measurement data correcting means 26 selects the measurement data file 231 relating to the inner and middle film thicknesses of the corresponding frequency and gain from the measurement data files 231a to 231n, and the measurement data 232 stored in the same file is selected from the measurement data 232 stored therein. Position data relating to the data of the inner and middle film thickness that approximates the value of the actual measurement data 262 is extracted (S42). Subsequently, the actual measurement data correction unit 26 selects the correction value data file 251 relating to the inner and middle film thicknesses of the corresponding frequency and gain from the correction value data files 251a to 251n. From the correction value data 252 stored in the selected file, the correction value data 252 relating to the inner / medium film thickness at the position corresponding to the extracted position data is read (S43), and the correction value data 252 is actually measured as the correction value 263. The data file 261 is stored. Then, the actual measurement value corrected by correcting the actual measurement data 262 based on the correction value 263 is calculated (S44). The corrected actual measurement value is stored in the actual measurement data file 261 as corrected actual measurement data 264 (S45), and the correction flow is terminated.

  The measurer can obtain the intima-media thickness of the carotid artery of the specimen in which the error on the image of the ultrasonic device 4 is corrected by referring to the corrected actual measurement data 264 stored in the actual measurement data file 261. .

According to the correction device 1 of the above embodiment, the following effects can be obtained.
(1) By using the correction device 1 of the above embodiment, a correction value for the measurement data of the ultrasonic device 4 can be obtained based on the measurement data and shape data of the carotid artery phantom 5, and the measurement of the ultrasonic device 4 can be obtained. The error can be reduced.

  (2) After the correction value is calculated by the correction device 1, the actual measurement data when the subject is measured by the ultrasonic device 4 can be corrected based on the correction value by the actual measurement data correction means 26. The measurement error of the ultrasonic device 4 can be reduced.

(3) Since the carotid artery phantom 5 is rotated and fed by the driving device 7, the correction value calculation work can be automated.
(4) An inner-medium-thickness displacement portion 55, a plaque phantom formation portion 56, and a stenosis displacement portion 57 formed along the axial direction are formed at different positions by 120 degrees in the circumferential direction of the carotid artery phantom 5 respectively. ing. Thereby, mutual interference can be minimized during ultrasonic measurement.

  (5) The plaque phantoms P1 to P6, which are disease sites, are formed in various shapes as well as a basic shape having a semicircular cross section. For this reason, it can respond to plaques of various shapes.

In addition, you may change the said embodiment as follows.
In the above correction device 1, when there are a plurality of frequencies and gains used in the ultrasonic device 4, the measurement data of the carotid artery phantom 5 is obtained in each pattern. However, the measurement data is obtained with only one frequency and gain. May be obtained. In this case, for other frequencies and gains, measurement data calculated by a predetermined arithmetic expression may be used.

  ○ In addition to making the frequency and gain different, if the dynamic range, time control sensitivity (STC), and echo Hans are made different, measurement data of the carotid artery phantom may be obtained under different conditions. .

  ○ In the measurement step S1, the carotid artery phantom 5 is fed and moved only in the axial direction to obtain two-dimensional measurement data. However, in addition to the feed movement, rotation may be added to obtain three-dimensional measurement data. . Further, the measurement data acquisition method of the carotid artery phantom 5 may be varied depending on the measurement target (intima or plaque).

  ○ The carotid artery phantom 5 is formed in a cylindrical shape, and each disease site of the medial-medial thickness displacement site 55, the plaque phantom formation site 56, and the stenosis displacement site 57 along the axial direction is a site where the circumferential angle is varied. However, the diseased sites may be formed along the circumferential direction at sites where the lengths in the axial direction are different. In addition, when each diseased part is formed in the circumferential direction, the diseased part is formed at a position facing the inner peripheral surface of the carotid artery phantom 5, and thus, for example, the diseased part is formed in a spiral shape. Interference can also be prevented.

  In the above embodiment, the carotid artery phantom 5 in which each of the diseased sites of the inner-media thickness displacement portion 55, the plaque phantom formation portion 56, and the stenosis displacement portion 57 is formed is used. A carotid artery phantom may be used for each diseased site, such as forming only the median thickness displacement site 55. Further, other types of disease sites may be formed in the carotid artery phantom 5.

Although the carotid artery phantom 5 is formed in a cylindrical shape, it is not limited to the same shape, and a branched portion may be formed in the same manner as in the actual carotid artery.
Although the plaque phantom P1 and the like are integrally formed with the carotid artery phantom 5, the plaque phantom P1 and the like may be attached to and detached from the carotid artery phantom 5. Accordingly, plaque phantoms having various shapes and ultrasonic characteristics can be attached to the carotid artery phantom as necessary, and the number of plaque phantom measurement objects can be increased.

  The driving of the carotid artery phantom 5 of the above embodiment is only rotation and feed movement, but further includes a third driving motor for adjusting the height of the carotid artery, and the relative distance between the carotid artery phantom 5 and the probe 41 is set. It may be arbitrarily adjustable. Further, in the measurement step (S1) of the carotid artery phantom 5, the measurement by the ultrasonic device 4 may be performed while rotating or feeding while changing the relative distance between the carotid artery phantom 5 and the probe 41.

  ○ Regarding the relative rotation and relative feed movement between the carotid artery phantom 5 and the probe 41, the carotid artery phantom 5 is rotated and fed, but the carotid artery phantom 5 is fixed and the probe 41 is rotated and fed. Good.

Conceptual diagram of correction apparatus and ultrasonic apparatus of this embodiment Schematic diagram of the phantom part Simple perspective view of the carotid artery phantom AA line sectional view of FIG. a is a sectional view taken along line BB in FIG. 4, b is a sectional view taken along line CC in FIG. 4, and c is a sectional view taken along line DD in FIG. Conceptual diagram of a computer constituting the correction device Simplified shape database Simplified measurement data file Simplified drawing of extracted data file Simplified correction value data file Simplified measurement data file a is a correction value calculation flowchart, b is a measurement flowchart, c is an extraction flowchart, d is a correction flowchart, and e is an actual measurement flowchart. Illustration of the carotid artery in the human body

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Correction apparatus, 2 ... Computer which comprises correction apparatus, 3 ... Phantom part which comprises correction apparatus, 4 ... Ultrasonic device, 5 ... Carotid artery phantom, 22 ... Shape data storage means, 23 ... Measurement data acquisition means, 24 ... shape data extracting means, 25 ... correction value calculating means, 26 ... actually measured data correcting means, 41 ... probe, 54 ... inner / thickness, 222 ... shape data, 232 ... measurement data, 242 ... partial shape data, 262 ... Actual measurement data, 263, correction values, P1 to P6, plaque phantom.

Claims (10)

A carotid artery phantom that is an artificial carotid artery model with diseased sites with different medial thickness, plaque size, arterial diameter, etc .;
Shape data storage means for storing carotid artery phantom shape data;
Measurement data acquisition means for acquiring measurement data obtained by measuring the carotid artery phantom as an image by a medical ultrasonic device;
Shape data extraction means for extracting the shape data of the carotid artery phantom of the diseased part corresponding to the measurement data acquired by the measurement data acquisition means as partial shape data from the shape data storage means;
Correction value calculation means for calculating a correction value for the measurement data based on the extracted partial shape data;
A correction device comprising: The correction apparatus according to claim 1, further comprising actual measurement data correction means for correcting actual measurement data of the subject's carotid artery obtained by an ultrasonic measurement apparatus based on the correction value. The correction apparatus according to claim 1, further comprising a moving device that relatively moves the carotid artery phantom and the probe of the ultrasonic device. The moving device rotates or feeds the carotid artery phantom on the same trajectory as the movement trajectory of the neck associated with relative rotation or relative feed movement of the subject with respect to the carotid artery with the probe of the ultrasonic device fixed. The correction apparatus according to claim 3, wherein the correction apparatus is provided. 5. The carotid artery phantom is formed so that a reference point for associating the measurement data acquired by the measurement data acquisition means with the position of the carotid artery phantom can be read by an ultrasonic device. The correction apparatus as described in any one of. In the carotid artery phantom, a plaque phantom that is a disease site is formed in the carotid artery site,
The correction device according to claim 1, wherein the plaque phantom has various shapes. The plaque phantom is made to have ultrasonic characteristics equivalent to the plaque of the subject in measurement by an ultrasonic device by distributing or mixing metal powder, rubber, polymer powder, or oil liquid inside. The correction device according to claim 6. The correction device according to claim 6 or 7, wherein the plaque phantom is integrally formed with the carotid artery phantom with respect to the inner peripheral surface of the carotid artery phantom. The carotid artery phantom has a cylindrical shape, and disease sites having different inner media thickness, plaque size, artery diameter, etc. are formed on the inner peripheral surface with equal intervals, and each disease site is in the axial direction of the carotid artery phantom. The correction apparatus according to any one of claims 1 to 8, wherein a disease state changes over a period of time. The correction device according to claim 1, wherein the measurement data acquisition unit acquires measurement data of a plurality of patterns with different operating frequencies and gains of the ultrasonic device. .

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