WO2014045925A1 - Ultrasonic analysis device, ultrasonic analysis method, and program - Google Patents

Ultrasonic analysis device, ultrasonic analysis method, and program Download PDF

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Publication number
WO2014045925A1
WO2014045925A1 PCT/JP2013/074306 JP2013074306W WO2014045925A1 WO 2014045925 A1 WO2014045925 A1 WO 2014045925A1 JP 2013074306 W JP2013074306 W JP 2013074306W WO 2014045925 A1 WO2014045925 A1 WO 2014045925A1
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Prior art keywords
ultrasonic
cartilage
echo signal
analysis
intensity
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PCT/JP2013/074306
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French (fr)
Japanese (ja)
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WO2014045925A8 (en
Inventor
弥 喜屋武
竜雄 新井
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古野電気株式会社
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Priority to JP2014536760A priority Critical patent/JP6190375B2/en
Publication of WO2014045925A1 publication Critical patent/WO2014045925A1/en
Publication of WO2014045925A8 publication Critical patent/WO2014045925A8/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/08—Detecting organic movements or changes, e.g. tumours, cysts, swellings
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/45—For evaluating or diagnosing the musculoskeletal system or teeth
    • A61B5/4514—Cartilage
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/46—Ultrasonic, sonic or infrasonic diagnostic devices with special arrangements for interfacing with the operator or the patient
    • A61B8/467—Ultrasonic, sonic or infrasonic diagnostic devices with special arrangements for interfacing with the operator or the patient characterised by special input means
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/52—Devices using data or image processing specially adapted for diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/5207—Devices using data or image processing specially adapted for diagnosis using ultrasonic, sonic or infrasonic waves involving processing of raw data to produce diagnostic data, e.g. for generating an image

Definitions

  • the present invention relates to an ultrasonic analysis apparatus, an ultrasonic analysis method, and a program for quantitatively analyzing the state of cartilage.
  • an intra-articular optical probe having a prism portion at the tip of an optical probe is brought into direct contact with the articular cartilage or irradiated with infrared rays to remove cartilage components.
  • the “hardness”, “thickness”, and “surface roughness” of the cartilage are quantitatively evaluated.
  • Patent Document 1 places a heavy burden on the subject.
  • an object of the present invention is to provide an ultrasonic analysis apparatus, an ultrasonic analysis method, and a program for quantitatively analyzing cartilage properties from the feature amount of echo signals from the cartilage surface obtained by transcutaneous measurement. .
  • the ultrasonic analysis apparatus of the present invention includes a transmission / reception unit that transmits an ultrasonic signal and receives an echo signal reflected inside the living body, and an intensity detection unit that detects the intensity of the echo signal.
  • the ultrasonic analysis apparatus of the present invention the analysis unit for analyzing the surface state of the cartilage based on the distribution of the intensity of the echo signal with respect to the incident angle of the ultrasonic signal with respect to the surface of the cartilage existing inside the living body, Is provided.
  • the incident angle of the ultrasonic signal with respect to the surface of the cartilage is manually input with a keyboard, for example.
  • Cartilage is composed of collagen, proteoglycan, water and the like.
  • collagen fibers are densely arranged on the cartilage surface. It is known that when cartilage is denatured, the collagen fibers are broken and the surface becomes rough.
  • Ultrasonic signals are almost regularly reflected when irradiated on normal cartilage with a dense surface. Therefore, the intensity of the echo signal is strongest when the ultrasonic wave is incident on a normal cartilage surface at 90 degrees.
  • the intensity of the echo signal is such that the incident angle of the ultrasonic wave with respect to the normal cartilage surface is small (for example, 60 degrees), compared to the position where it is 90 degrees, because of the property of normal cartilage that regularly reflects the ultrasonic wave. become weak. That is, the intensity of the echo signal is strongly dependent on the incident angle in the case of normal cartilage.
  • the ultrasonic signal is irregularly reflected when it is irradiated on the denatured cartilage having a rough surface.
  • the intensity of the echo signal does not change much compared to the case of normal cartilage even when the incident angle of the ultrasonic wave on the surface of the cartilage changes. That is, the intensity of the echo signal is weakly dependent on the incident angle in the case of denatured cartilage.
  • the analysis unit of the ultrasonic analysis apparatus of the present invention quantitatively obtains the degree that the intensity of the echo signal depends on the incident angle of the ultrasonic wave with respect to the surface of the cartilage, and analyzes the surface state of the cartilage. Therefore, the measurer can cause the ultrasonic analysis apparatus of the present invention to quantitatively analyze the surface state of the cartilage by transcutaneous measurement.
  • the intensity detection unit of the ultrasonic analysis apparatus of the present invention compares echo signals obtained in a plurality of states in which the positional relationship between the soft tissue and the cartilage with respect to the transmission / reception unit is different, and the waveforms of the echo signals in the plurality of states are the most similar
  • the cartilage surface is detected from the change in the relative position of the region with respect to the transmission / reception unit, and the intensity of the echo signal reflected from the cartilage surface is detected among the echo signals.
  • the intensity detection unit detects the cartilage surface, identifies the echo signal from the cartilage surface, and detects the intensity of the echo signal.
  • the analysis unit of the ultrasonic analysis apparatus of the present invention includes a time difference detection unit.
  • the time difference detection unit detects a time difference from the transmission timing of the ultrasonic signals transmitted at different positions on the surface of the living body to the reception timing of the echo signal detected based on each ultrasonic signal, and detects the detected time difference. Is sent to the analysis department.
  • the time difference obtained by the time difference detector is the sum of the time for the ultrasonic signal to reach the cartilage surface from the transmitter / receiver and the time for the echo signal to reach the transmitter / receiver from the cartilage surface, that is, the cartilage from the transmitter / receiver element surface. It is the time to travel back and forth on the surface. Therefore, the distance obtained by dividing the time difference obtained by the time difference detection unit by 2 and multiplying by the sound speed of the medium is the distance from the transmission / reception unit to the cartilage surface.
  • the analysis unit can calculate the position of the measurement point on the cartilage surface. Then, the analysis unit obtains an approximate straight line (one-dimensional) or an approximate surface (two-dimensional) of the plurality of measurement points on the obtained cartilage surface.
  • the approximate straight line and the approximate surface are obtained by the least square method or the like.
  • the analysis unit obtains an angle at which the traveling direction of the ultrasonic signal with respect to the approximate surface is inclined from the normal direction of the approximate surface and the direction in which the ultrasonic wave travels, and determines the obtained angle as the incident angle of the ultrasonic signal.
  • the ultrasonic analysis apparatus of the present invention obtains the incident angle of the ultrasonic signal with respect to the cartilage surface by capturing the position and shape of the cartilage surface in three dimensions even if the position of the cartilage surface is not detected before the analysis. The surface condition of the cartilage can be analyzed.
  • the transmitter / receiver of the ultrasonic analyzer of the present invention sequentially scans the surface of the living body, transmits an ultrasonic signal at each of a plurality of positions on the surface of the living body, and receives an echo signal. Therefore, the measurer can cause the ultrasonic analyzer to continuously analyze the surface of the cartilage.
  • the ultrasonic analysis apparatus of the present invention has a plurality of transmission / reception units, and each transmission / reception unit transmits an ultrasonic signal and receives an echo signal at each of a plurality of positions on the surface of the living body. With this configuration, the ultrasonic analysis apparatus of the present invention analyzes the surface of the cartilage at a plurality of positions at the same time.
  • the analysis unit of the ultrasonic analysis apparatus of the present invention obtains a regression line of the echo signal intensity distribution with respect to the incident angle, and quantitatively analyzes the cartilage surface state based on the slope of the regression line.
  • the inclination of the regression line corresponds to the degree of dependence of the echo signal intensity on the incident angle of the ultrasonic signal. Therefore, the analysis unit can determine the slope of the regression line as a quantitative degree that the surface of the cartilage is denatured.
  • the analysis unit of the ultrasonic analysis apparatus of the present invention determines that the surface of the cartilage is denatured as the absolute value of the slope of the regression line is closer to zero. Accordingly, the measurer can cause the ultrasonic analyzer of the present invention to quantitatively determine whether or not the cartilage is degenerated.
  • the analysis unit of the ultrasonic analysis apparatus of the present invention determines that the surface of the cartilage is degenerated if the absolute value of the slope of the regression line is smaller than a predetermined threshold, other than quantitatively determining cartilage degeneration. . Therefore, the measurer can cause the ultrasonic analyzer of the present invention to determine whether the cartilage is degenerated.
  • the ultrasonic analysis system includes the ultrasonic analysis device according to the present invention and a display unit that displays the result of analysis by the analysis unit of the ultrasonic analysis device.
  • the measurer can know the result of visually analyzing the distribution of the intensity of the echo signal with respect to the incident angle of the ultrasonic signal (comparison with the distribution, the slope of the regression line, and a predetermined threshold). .
  • the present invention is not limited to an ultrasonic analysis apparatus, but may be a method of analyzing with ultrasonic waves or an ultrasonic analysis program executed by an information processing apparatus.
  • the distribution of the echo signal intensity with respect to the incident angle of the ultrasonic signal to the cartilage surface is analyzed from the feature quantity of the echo signal from the cartilage surface obtained by transcutaneous measurement, and the cartilage degeneration is quantified. Analysis.
  • FIG. 1 is a diagram showing the configuration of the ultrasonic analysis system of the present invention and the inside of a knee joint.
  • a transducer 2 is attached to the tip of the ultrasonic probe 1.
  • the ultrasonic probe 1 and the monitor 4 are connected to the computer 3.
  • the transducer 2 is used in contact with the knee of the subject.
  • the drive mechanism 6 drives the ultrasonic probe 1 in parallel along the axis of the drive mechanism 6 based on instructions from the computer 3.
  • the ultrasonic probe 1 controls the operation of the transducer 2.
  • the ultrasonic probe 1 receives an ultrasonic signal transmission instruction from the computer 3 and sends it to the transducer 2.
  • the transducer 2 irradiates the knee cartilage 5 with an ultrasonic signal based on the transmission instruction.
  • the transducer 2 receives an echo signal reflected from the surface of the knee cartilage 5 and sends a reception signal corresponding to the level of the echo signal to the ultrasonic probe 1.
  • the ultrasonic probe 1 sends the reception signal received from the transducer 2 to the computer 3.
  • the ultrasonic analysis system measures the knee cartilage 5 sequentially by the drive mechanism 6 driving the ultrasonic probe 1. Note that the transducer 2 is not an essential component of the present invention, and the ultrasonic probe 1 may transmit and receive ultrasonic waves according to instructions from the computer 3.
  • FIG. 2A is a block diagram of the computer 3.
  • the computer 3 includes a receiving unit 30, a transmitting unit 31, a signal processing unit 32, an image processing unit 33, and a control unit 34.
  • the control unit 34 controls operations of the reception unit 30, the transmission unit 31, the signal processing unit 32, the image processing unit 33, and the drive mechanism 6.
  • the receiving unit 30 receives a reception signal from the ultrasonic probe 1.
  • the receiving unit 30 performs A / D conversion on the received signal and sends it to the signal processing unit 32.
  • the transmission unit 31 sends a transmission instruction to the ultrasonic probe 1 in accordance with an instruction from the control unit 34.
  • the signal processing unit 32 includes an intensity detection unit 320, a time difference detection unit 321, and an analysis unit 322 as shown in FIG.
  • FIG. 3 is a diagram showing a received signal.
  • the horizontal axis represents time
  • the vertical axis represents voltage (amplitude).
  • the intensity detection unit 320 detects the intensity of the echo signal and the reception timing using the information on the reception signal obtained from the reception unit 30 (the voltage of the reception signal for each time). Specifically, the intensity detection unit 320 sets the value of the highest voltage within a predetermined time (for example, within 100 ⁇ s) as the intensity of the echo signal, and sets the timing when the voltage reaches the maximum as the reception timing. For example, the intensity of the echo signal in FIG. 3 is about 0.4 V, and the reception timing is when about 40 ⁇ s has elapsed.
  • the reception timing is not limited to the timing when the intensity of the echo signal reaches the maximum voltage, but the timing when the maximum voltage of the envelope of the intensity of the echo signal shown in FIG. 3 or the intensity of the echo signal shown in FIG. It is good also as the timing of the zero crossing point which is the closest time from the timing when the differential value of the intensity of the echo signal is equal to or greater than a predetermined threshold.
  • the intensity detecting unit 320 may detect the cartilage surface by the following method, and detect the echo signal intensity and the visit timing of the cartilage surface.
  • the following method can be considered.
  • the ultrasonic probe 1 is brought into contact with the knee surface to receive an echo signal. This is the echo signal in the first state.
  • the ultrasonic probe 1 is moved in contact with the knee surface, and an echo signal is received. This is the echo signal in the second state.
  • the cartilage does not move even if the ultrasonic probe 1 is moved while being in contact with the knee surface, the soft tissue existing between the cartilage surface and the knee surface moves following the movement of the ultrasonic probe 1. To do. Therefore, the relative position of the soft tissue in the first state and the second state does not change in the first state and the second state, but the relative position of the cartilage in the first state and the second state changes in the first state and the second state.
  • a region where the waveforms of the echo signal in the first state and the echo signal in the second state are similar is detected, and the relative positional relationship between the similar region and the ultrasonic probe 1 is the first state and the first state.
  • a boundary between a region that changes in two states and a region that does not change is detected. This boundary is detected as the knee cartilage surface.
  • the intensity detector 320 sends the detected intensity of the echo signal to the analyzer 322, and sends the intensity of the echo signal and the reception timing to the time difference detector 321.
  • the control unit 34 sends to the time difference detection unit 321 the timing when the transmission unit 31 gives a transmission instruction. Then, the time difference detection unit 321 calculates a time difference from the timing when the transmission instruction is given to the reception timing. Next, the time difference detection unit 321 sends the detected time difference to the analysis unit 322.
  • the time difference obtained by the time difference detection unit 321 corresponds to the distance from the transducer 2 (biological surface) to the surface of the knee cartilage 5.
  • the time difference sent from the time difference detection unit 321 is the time for the ultrasonic wave to reciprocate from the transducer 2 (biological surface) to the surface of the knee cartilage 5.
  • the analysis unit 322 multiplies the detected time difference at the point where the ultrasonic signal is radiated on the surface of the living body by the speed at which the ultrasonic wave travels inside the living body, and further divides the result by 2 from the transducer 2 (biological surface) to the knee. The distance to the surface of the cartilage 5 is obtained.
  • FIG. 4 (A) is a diagram showing the internal structure of the knee joint when the right knee joint is viewed from the inside to the outside.
  • the + Z side is the front side of the knee
  • the ⁇ Z side is the back side of the knee.
  • the + Y side is the trunk side
  • the -Y side is the toe side.
  • the range occupied by the dotted line in FIG. 4A is a range in which an ultrasonic signal is irradiated on the outer skin of the right knee.
  • the computer 3 controls the drive mechanism 6 so that the ultrasonic probe 1 scans along the line in FIG.
  • FIG. 4B is a diagram when the range occupied by the dotted line portion in FIG. 4A is viewed from the + Z side toward the ⁇ Z side.
  • the direction in which the value of X increases is the direction inside the right knee.
  • Each black dot is a position irradiated with an ultrasonic signal.
  • FIG. 4C is an enlarged view of a part of the diagram in FIG. 4B (the range of the solid line in the square).
  • the range irradiated with ultrasonic waves is divided into small areas and numbered (L1 to L4).
  • numbers (N1 to N9) are assigned to the points irradiated with the ultrasonic waves in the small region L1.
  • the ultrasonic signal and the echo signal are sequentially scanned at each point and transmitted / received by the transducer 2.
  • a plurality of ultrasonic probes 1 may be used for simultaneous scanning.
  • the analysis unit 322 obtains the distance from each point to the cartilage surface from the transducer 2 (biological surface) at each point N1 to N9 in the small region L1. Further, the analysis unit 322 obtains the position where the ultrasonic signal is reflected on the surface of the knee cartilage 5 from the direction vector of the ultrasonic signal and the distance to the cartilage surface.
  • FIG. 5A is a diagram showing the depth from the surface of the living body to the surface of the knee cartilage 5 at each position where the ultrasonic signal shown in FIGS. 4A and 4B is irradiated. The distance to the surface of the knee cartilage 5 obtained from the analysis unit 322 corresponds to the depth from the surface of the living body to the knee cartilage 5.
  • FIG. 5A is a diagram showing that the surface of the knee cartilage 5 is closer to the inside of the living body as the depth value is smaller.
  • the black dots shown in FIG. 5A are M1 to M9 obtained by the analysis unit 322.
  • FIG. 5B is a diagram showing the depth value of each point in one dimension (X direction).
  • M1 is a position where the ultrasonic signal irradiated from N1 is reflected on the surface of the knee cartilage 5.
  • the analysis unit 322 calculates M2 to M9 corresponding to N2 to N9, respectively, similarly to the calculation of the position of M1.
  • a small region K1 shown in FIG. 5B is a one-dimensional representation of a part of the surface composed of M1 to M9, and is a curved portion passing through M1 to M3.
  • the analysis unit 322 can obtain the partial shape of the surface of the knee cartilage 5 by obtaining the position (M1 to M9) of the surface of the knee cartilage 5.
  • the analysis unit 322 obtains an approximate straight line of the small region K1.
  • the approximate straight line is obtained by the method of least squares. That is, the analysis unit 322 obtains the square value of the residual from each point M1 to M3 to the approximate line, and obtains the normal vector of the approximate plane so that the sum of the square values obtained for each point is minimized.
  • the method of obtaining the approximate plane is not limited to the least square method. Note that the analysis unit 322 obtains an approximate plane of the small region when the small region is two-dimensional (a surface composed of the X axis and the Y axis).
  • the analysis unit 322 obtains the angle formed by the traveling direction vector of the ultrasonic signal irradiated to M2, which is the center of the small region K1, and the normal vector of the obtained approximate straight line, and the obtained angle is determined as the small region K1.
  • the analysis unit 322 associates the average value of the intensity of the echo signal detected by the intensity detection unit 320 in N1 to N3 with the incident angle of the ultrasonic signal in the small region K1.
  • the analysis unit 322 uses the normal vector of the approximate plane and the traveling direction vector of the ultrasonic signal irradiated to M5 which is the center of M1 to M9, to the knee cartilage surface. Find the incident angle. Further, in this case, the analysis unit 322 obtains the average value of the echo signal intensity from the intensity of the echo signal detected at N1 to N9.
  • the control unit 34 controls the drive mechanism 6 to cause the intensity detection unit 320 and the time difference detection unit 321 to detect the intensity and time difference of the echo signal even in a small region other than K1. Then, the control unit 34 causes the analysis unit 322 to associate the average value of the echo signal intensity in each small region with the incident angle of the ultrasonic signal in the small region.
  • FIG. 6 is a diagram showing an incident angle of the ultrasonic signal with respect to the surface of the knee cartilage 5 at each position irradiated with the ultrasonic signal shown in FIGS. 4 (A) and 4 (B).
  • FIG. 7 is a diagram showing the intensity of the echo signal at each position irradiated with the ultrasonic signal shown in FIGS. 4 (A) and 4 (B).
  • the analysis unit 322 creates the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal. Then, the analysis unit 322 performs statistical analysis on the created distribution.
  • the analysis unit 322 obtains a regression line of the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal, for example, by a least square method for statistical analysis.
  • the absolute value of the slope of the regression line is a degree that the intensity of the echo signal depends on the incident angle of the ultrasonic signal. Therefore, the analysis unit 322 can obtain the degree of dependence as a quantitative value.
  • the analysis unit 322 sends the analysis result to the image processing unit 33.
  • the analysis result shows that the distance to the surface of the knee cartilage 5 and the incident angle of the ultrasonic signal, the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal, and the distribution It is a regression line.
  • the image processing unit 33 generates an image for displaying the analysis result received from the analysis unit 322 as a two-dimensional graph, and sends the image to the monitor 4. Then, the control unit 34 causes the monitor 4 to display the image. Therefore, the measurer can visually recognize the analysis result.
  • the monitor 4 is not an essential component in the present invention, and may be an aspect in which an analysis result is printed by a printing unit.
  • FIG. 8 is a diagram showing an image displayed on the monitor 4. 8A and 8B, the horizontal axis represents the incident angle of the ultrasonic signal, the vertical axis represents the intensity of the echo signal, and a plurality of data including the average intensity of the echo signal and the incident angle of the ultrasonic signal. Is plotted (data and the like in the small region L1).
  • FIG. 8A is a diagram showing the analysis result of normal cartilage.
  • FIG. 8B is a diagram showing the analysis result of denatured cartilage.
  • the absolute value of the slope of the regression line is 0.9
  • the absolute value of the slope of the regression line is 0.1.
  • the intensity of the echo signal for normal cartilage is angle-dependent because the absolute value of the slope of the regression line is as large as 0.9 as shown in FIG.
  • the absolute value of the slope of the regression line is 0.1, which is smaller than the absolute value of the slope of the normal cartilage regression line, the intensity of the echo signal for the degenerated cartilage has no angle dependency.
  • the measurer can quantitatively know the degree of cartilage degeneration based on the absolute value of the slope of the regression line shown in FIG. 8A or 8B displayed on the monitor 4.
  • the analysis unit 322 has a smaller absolute value of the slope of the regression line of FIG. 8B than the absolute value of the slope of the regression line of FIG. 8A, so that as shown in FIG. Judge that the analyzed cartilage is more denatured.
  • the measurer can determine which knee cartilage is more denatured by causing the ultrasonic analysis system to analyze the left knee cartilage and the right knee cartilage.
  • the analysis unit 322 of the ultrasonic analysis system determines that the analyzed cartilage is degenerated when the absolute value of the slope of the regression line is smaller than a predetermined threshold value. For example, when the predetermined threshold value is 0.5, in the example shown in FIG. 8A, the analysis unit 322 determines that the slope of the approximate line is 0.9, which is larger than the threshold value, and is normal cartilage. On the other hand, in the example shown in FIG. 8B, the analysis unit 322 determines that the absolute value of the slope of the regression line is 0.1, which is smaller than the threshold, and is degenerated cartilage. The analysis unit 322 sends the determination result to the image processing unit 33, and the control unit 34 can display the image on the monitor 4.
  • a predetermined threshold value is 0.5
  • the analysis unit 322 determines that the slope of the approximate line is 0.9, which is larger than the threshold value, and is normal cartilage.
  • the analysis unit 322 determines that the absolute value of the slope of the regression line is 0.1, which is smaller than the
  • the predetermined threshold value is not limited to one and may be plural.
  • the analysis unit 322 can determine the degeneration of the cartilage in a stepwise manner, for example, one of normal, slightly denatured, considerably denatured, and immediate treatment required.
  • the analysis unit 322 can determine the degree of cartilage degeneration using the absolute value of the slope of the regression line as the normal degree (for example, the normality is 90% when the absolute value of the slope is 0.9).
  • the control unit 34 can cause the monitor 4 to display not only FIG. 8 but also FIGS. 5 to 7 as analysis results.
  • the present invention may be an embodiment in which the degree of modification is determined by the measurer himself from the displayed FIGS.
  • the ultrasonic analysis system of the present invention can quantitatively analyze the degree of degeneration of the knee cartilage 5 by calculating the absolute value of the slope of the regression line. Further, the measurer can recognize the quantitative analysis result by displaying the analysis result on the monitor 4.
  • the drive mechanism 6 in the above example is not an essential configuration of the present invention.
  • the ultrasonic irradiation position may be moved manually to measure at a plurality of positions.
  • strength detection part 320 of said example processes the digital data transmitted from the receiving part 30, it is not restricted to this aspect.
  • An aspect may be possible in which the intensity detection unit 320 receives an analog reception signal from the reception unit 30 and processes the reception signal.
  • the ultrasonic analysis system of the present invention may be an aspect in which the ultrasonic probe 1 and the monitor 4 are excellently portable and configured integrally with the computer 3.
  • the absolute value of the slope of the regression line is obtained, but the average intensity of the echo signal and the ultrasonic signal for the knee cartilage 5 are calculated.
  • the correlation coefficient of the incident angle may be obtained and analyzed.
  • the analysis unit 322 determines that the correlation coefficient is closer to ⁇ 1 (negative correlation) as normal cartilage, and the correlation coefficient is 0 (none). If the value is close to (correlation), it is determined that the cartilage is degenerated.
  • the time difference detected by the time difference detection unit 321 is multiplied by the ultrasonic traveling speed to obtain the distance to the surface of the knee cartilage 5.
  • the distance is only calculated because it can be recognized.
  • the present invention can analyze the surface state of the cartilage without obtaining the distance from the transducer 2 to the surface of the knee cartilage 5. That is, the analysis unit 322 obtains an approximate plane in the space composed of the X axis, the Y axis, and the time difference axis, and uses the inclination angle of the approximate plane as the incident angle of the ultrasonic signal, and the incident angle and the average intensity of the echo signal The correlation may be analyzed. Alternatively, the measurement person may manually input the incident angle through a keyboard connected to the computer 3 and give the incident angle to the analysis unit 322.
  • the approximate straight line is calculated from 3 points (the approximate plane is calculated using 9 points), but is not limited to 3 points.
  • the unit of the intensity of the echo signal of this embodiment is dB as shown in FIGS. 8A and 8B, but may be Volt which is a unit of voltage.
  • the absolute value of the voltage of the echo signal is small for a subject with a thick soft tissue from the surface of the living body to the surface of the knee cartilage 5, and the absolute value of the amount of change is also small. Significant differences in absolute values are less likely to appear.
  • the absolute value of the slope of the regression line is a significant difference because it is converted to a relative value even if the echo signal voltage is detected low.

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Abstract

[Problem] To provide an ultrasonic analysis device, ultrasonic analysis method, and program for quantitatively analyzing the surface condition of cartilage. [Solution] The present invention makes use of the property of ultrasonic waves being diffusely reflected at the surface of modified cartilage. An analysis unit uses sets of data comprising the intensity of echo signals detected by an intensity detection unit and the angle of incidence of ultrasonic signals on the surface of cartilage, to quantitatively analyze the surface condition of cartilage on the basis of the distribution of the sets of data. The angle of incidence of the ultrasonic signals on the surface of the cartilage is inputted with, for example, a keyboard.

Description

超音波解析装置、超音波解析方法及びプログラムUltrasonic analysis apparatus, ultrasonic analysis method and program
　本発明は、軟骨の状態を定量的に解析するための超音波解析装置、超音波解析方法及びプログラムに関する。 The present invention relates to an ultrasonic analysis apparatus, an ultrasonic analysis method, and a program for quantitatively analyzing the state of cartilage.
　従来、関節腔内の軟骨の状態を直感的且つ定量的に評価するために、軟骨に超音波を当て、その反射エコーに基づいて解析データを生成するシステムが各種考案されている。 Conventionally, in order to intuitively and quantitatively evaluate the state of the cartilage in the joint cavity, various systems have been devised that apply ultrasonic waves to the cartilage and generate analysis data based on the reflected echo.
　例えば、特許文献１に示す超音波解析システムでは、先端に光プローブの先端部にプリズム部を有した関節内光プローブを、関節軟骨に直接接触させ、または赤外線を照射して、軟骨の成分を測定することにより、軟骨の「硬さ」、「厚さ」、および「表面粗さ」を定量的に評価している。 For example, in the ultrasonic analysis system disclosed in Patent Document 1, an intra-articular optical probe having a prism portion at the tip of an optical probe is brought into direct contact with the articular cartilage or irradiated with infrared rays to remove cartilage components. By measuring, the “hardness”, “thickness”, and “surface roughness” of the cartilage are quantitatively evaluated.
特許第４６５４４３０号Patent No. 4654430
　しかしながら、特許文献１に示すような方法は、被験者に大きな負担を強いる。 However, the method shown in Patent Document 1 places a heavy burden on the subject.
　そこで、本発明の目的は、経皮測定で得られた軟骨表面からのエコー信号の特徴量から軟骨性状を定量的に解析する超音波解析装置、超音波解析方法及びプログラムを提供することにある。 Therefore, an object of the present invention is to provide an ultrasonic analysis apparatus, an ultrasonic analysis method, and a program for quantitatively analyzing cartilage properties from the feature amount of echo signals from the cartilage surface obtained by transcutaneous measurement. .
　本発明の超音波解析装置は、超音波信号を送信し、生体内部で反射したエコー信号を受信する送受信部と、前記エコー信号の強度を検出する強度検出部と、を備える。 The ultrasonic analysis apparatus of the present invention includes a transmission / reception unit that transmits an ultrasonic signal and receives an echo signal reflected inside the living body, and an intensity detection unit that detects the intensity of the echo signal.
　そして、本発明の超音波解析装置は、前記超音波信号の前記生体内部に存する軟骨の表面に対する入射角度に対する前記エコー信号の強度の分布、に基づいて前記軟骨の表面状態を解析する解析部、を備える。 And the ultrasonic analysis apparatus of the present invention, the analysis unit for analyzing the surface state of the cartilage based on the distribution of the intensity of the echo signal with respect to the incident angle of the ultrasonic signal with respect to the surface of the cartilage existing inside the living body, Is provided.
　軟骨の表面に対する超音波信号の入射角度は、例えば、キーボードで手入力される。 The incident angle of the ultrasonic signal with respect to the surface of the cartilage is manually input with a keyboard, for example.
　軟骨は、コラーゲン、プロテオグリカン、水等からなる。正常な軟骨は、コラーゲン繊維が軟骨表面で密に配置されている。軟骨は、変性すると、コラーゲン繊維が断裂し、表面が粗くなることが知られている。 Cartilage is composed of collagen, proteoglycan, water and the like. In normal cartilage, collagen fibers are densely arranged on the cartilage surface. It is known that when cartilage is denatured, the collagen fibers are broken and the surface becomes rough.
　超音波信号は、表面が密である正常な軟骨に照射されると、ほぼ正反射する。したがって、エコー信号の強度は、正常な軟骨表面に対し超音波が９０度で入射する場合、最も強い。エコー信号の強度は、正常な軟骨表面に対する超音波の入射角度が、小さくなる（例えば６０度となる）位置では、超音波を正反射させる正常軟骨の性質から、９０度となる位置に比べ、弱くなる。すなわち、エコー信号の強度は、正常な軟骨であれば、入射角度に強く依存する。一方、超音波信号は、表面が粗い変性軟骨に照射されると、乱反射する。したがって、エコー信号の強度は、軟骨の表面に対する超音波の入射角度が変化しても、正常な軟骨の場合と比べ、あまり変化しない。すなわち、エコー信号の強度は、変性した軟骨であれば、入射角度に依存する度合いが弱い。 ∙ Ultrasonic signals are almost regularly reflected when irradiated on normal cartilage with a dense surface. Therefore, the intensity of the echo signal is strongest when the ultrasonic wave is incident on a normal cartilage surface at 90 degrees. The intensity of the echo signal is such that the incident angle of the ultrasonic wave with respect to the normal cartilage surface is small (for example, 60 degrees), compared to the position where it is 90 degrees, because of the property of normal cartilage that regularly reflects the ultrasonic wave. become weak. That is, the intensity of the echo signal is strongly dependent on the incident angle in the case of normal cartilage. On the other hand, the ultrasonic signal is irregularly reflected when it is irradiated on the denatured cartilage having a rough surface. Therefore, the intensity of the echo signal does not change much compared to the case of normal cartilage even when the incident angle of the ultrasonic wave on the surface of the cartilage changes. That is, the intensity of the echo signal is weakly dependent on the incident angle in the case of denatured cartilage.
　本発明の超音波解析装置の解析部は、エコー信号の強度が軟骨の表面に対する超音波の入射角度に依存している度合いを定量的に求め、軟骨の表面状態を解析する。したがって、測定者は、本発明の超音波解析装置に、経皮測定で、軟骨の表面状態を定量的に解析させることができる。 The analysis unit of the ultrasonic analysis apparatus of the present invention quantitatively obtains the degree that the intensity of the echo signal depends on the incident angle of the ultrasonic wave with respect to the surface of the cartilage, and analyzes the surface state of the cartilage. Therefore, the measurer can cause the ultrasonic analysis apparatus of the present invention to quantitatively analyze the surface state of the cartilage by transcutaneous measurement.
　また、本発明の超音波解析装置の強度検出部は、送受信部に対する軟組織と軟骨の位置関係が異なる複数の状態で得たエコー信号を比較し、複数の状態のエコー信号の波形が最も類似する領域の送受信部に対する相対位置の変化から軟骨表面を検出し、エコー信号のうち軟骨表面で反射したエコー信号の強度を検出する。 Further, the intensity detection unit of the ultrasonic analysis apparatus of the present invention compares echo signals obtained in a plurality of states in which the positional relationship between the soft tissue and the cartilage with respect to the transmission / reception unit is different, and the waveforms of the echo signals in the plurality of states are the most similar The cartilage surface is detected from the change in the relative position of the region with respect to the transmission / reception unit, and the intensity of the echo signal reflected from the cartilage surface is detected among the echo signals.
　このようにして、強度検出部は、軟骨表面を検出して、当該軟骨表面からエコー信号を識別し、エコー信号の強度を検出する。 In this way, the intensity detection unit detects the cartilage surface, identifies the echo signal from the cartilage surface, and detects the intensity of the echo signal.
　また、本発明の超音波解析装置の解析部は、時間差検出部を備える。時間差検出部は、生体表面の互いに異なる位置でそれぞれ送信された超音波信号の送信タイミングから、各超音波信号に基づいてそれぞれ検出した前記エコー信号の受信タイミングまでの時間差を検出し、検出した時間差を解析部に送る。 Further, the analysis unit of the ultrasonic analysis apparatus of the present invention includes a time difference detection unit. The time difference detection unit detects a time difference from the transmission timing of the ultrasonic signals transmitted at different positions on the surface of the living body to the reception timing of the echo signal detected based on each ultrasonic signal, and detects the detected time difference. Is sent to the analysis department.
　時間差検出部によって求められる時間差は、超音波信号が送受信部から軟骨表面に到達する時間と、エコー信号が軟骨表面から送受信部に到達する時間と、を合計した時間、すなわち送受信部素子面から軟骨表面を往復伝搬する時間である。したがって，時間差検出部によって求められる時間差を２で割って媒質の音速を乗算した距離が送受信部から軟骨表面までの距離となる。 The time difference obtained by the time difference detector is the sum of the time for the ultrasonic signal to reach the cartilage surface from the transmitter / receiver and the time for the echo signal to reach the transmitter / receiver from the cartilage surface, that is, the cartilage from the transmitter / receiver element surface. It is the time to travel back and forth on the surface. Therefore, the distance obtained by dividing the time difference obtained by the time difference detection unit by 2 and multiplying by the sound speed of the medium is the distance from the transmission / reception unit to the cartilage surface.
　このようにして解析部は、軟骨表面の測定点の位置を算出することができる。そして、解析部は、求められた軟骨表面の複数の測定点の近似直線（一次元）または近似面（二次元）を求める。近似直線および近似面は、最小二乗法等によって求められる。 In this way, the analysis unit can calculate the position of the measurement point on the cartilage surface. Then, the analysis unit obtains an approximate straight line (one-dimensional) or an approximate surface (two-dimensional) of the plurality of measurement points on the obtained cartilage surface. The approximate straight line and the approximate surface are obtained by the least square method or the like.
　次に、解析部は、近似面の法線方向と超音波が進行する方向から、当該近似面に対する超音波信号の進行方向が傾斜する角度を求め、求めた角度を超音波信号の入射角度とする。したがって、本発明の超音波解析装置は、解析前に軟骨の表面の位置が検知されてなくても、軟骨表面の位置および形状を立体的にとらえ、軟骨表面に対する超音波信号の入射角度を求めることができ、軟骨の表面状態を解析することができる。 Next, the analysis unit obtains an angle at which the traveling direction of the ultrasonic signal with respect to the approximate surface is inclined from the normal direction of the approximate surface and the direction in which the ultrasonic wave travels, and determines the obtained angle as the incident angle of the ultrasonic signal. To do. Therefore, the ultrasonic analysis apparatus of the present invention obtains the incident angle of the ultrasonic signal with respect to the cartilage surface by capturing the position and shape of the cartilage surface in three dimensions even if the position of the cartilage surface is not detected before the analysis. The surface condition of the cartilage can be analyzed.
　本発明の超音波解析装置の送受信部は、生体表面を順次スキャンして、生体表面の複数の位置の各位置において、超音波信号を送信し、かつエコー信号を受信する。したがって、測定者は、超音波解析装置に、連続して軟骨の表面の解析をさせることができる。 The transmitter / receiver of the ultrasonic analyzer of the present invention sequentially scans the surface of the living body, transmits an ultrasonic signal at each of a plurality of positions on the surface of the living body, and receives an echo signal. Therefore, the measurer can cause the ultrasonic analyzer to continuously analyze the surface of the cartilage.
　また、本発明の超音波解析装置は、複数の送受信部を有し、各送受信部は、生体表面の複数の位置の各位置において、超音波信号を送信し、かつエコー信号を受信する。この構成により、本発明の超音波解析装置は、同時に複数の位置において、軟骨の表面を解析する。 Also, the ultrasonic analysis apparatus of the present invention has a plurality of transmission / reception units, and each transmission / reception unit transmits an ultrasonic signal and receives an echo signal at each of a plurality of positions on the surface of the living body. With this configuration, the ultrasonic analysis apparatus of the present invention analyzes the surface of the cartilage at a plurality of positions at the same time.
　また、本発明の超音波解析装置の解析部は、入射角度に対するエコー信号の強度の分布の回帰直線を求め、当該回帰直線の傾きに基づき、軟骨の表面状態を定量的に解析する。回帰直線の傾きは、超音波信号の入射角度に対するエコー信号の強度の依存の度合いに対応する。したがって、解析部は、軟骨の表面が変性している定量的な度合いとして、回帰直線の傾きを求めることができる。 Also, the analysis unit of the ultrasonic analysis apparatus of the present invention obtains a regression line of the echo signal intensity distribution with respect to the incident angle, and quantitatively analyzes the cartilage surface state based on the slope of the regression line. The inclination of the regression line corresponds to the degree of dependence of the echo signal intensity on the incident angle of the ultrasonic signal. Therefore, the analysis unit can determine the slope of the regression line as a quantitative degree that the surface of the cartilage is denatured.
　また、本発明の超音波解析装置の解析部は、回帰直線の傾きの絶対値が０に近いほど軟骨の表面が変性していると判断する。したがって、測定者は、本発明の超音波解析装置に、軟骨が変性しているか否かを定量的に判断させることができる。 In addition, the analysis unit of the ultrasonic analysis apparatus of the present invention determines that the surface of the cartilage is denatured as the absolute value of the slope of the regression line is closer to zero. Accordingly, the measurer can cause the ultrasonic analyzer of the present invention to quantitatively determine whether or not the cartilage is degenerated.
　本発明の超音波解析装置の解析部は、定量的に軟骨の変性を判断する以外でも、回帰直線の傾きの絶対値が所定の閾値より小さいと、軟骨の表面が変性していると判断する。したがって、測定者は、本発明の超音波解析装置に、軟骨が変性しているか否かのどちらかを、判断させることができる。 The analysis unit of the ultrasonic analysis apparatus of the present invention determines that the surface of the cartilage is degenerated if the absolute value of the slope of the regression line is smaller than a predetermined threshold, other than quantitatively determining cartilage degeneration. . Therefore, the measurer can cause the ultrasonic analyzer of the present invention to determine whether the cartilage is degenerated.
　本発明の超音波解析システムは、本発明の超音波解析装置と、当該超音波解析装置の解析部が解析した結果を表示する表示部と、を備える。この構成により、測定者は、視覚的に超音波信号の入射角度に対するエコー信号の強度の分布を解析した結果（当該分布、回帰直線の傾き、および所定の閾値との比較）を知ることができる。 The ultrasonic analysis system according to the present invention includes the ultrasonic analysis device according to the present invention and a display unit that displays the result of analysis by the analysis unit of the ultrasonic analysis device. With this configuration, the measurer can know the result of visually analyzing the distribution of the intensity of the echo signal with respect to the incident angle of the ultrasonic signal (comparison with the distribution, the slope of the regression line, and a predetermined threshold). .
　本発明は、超音波解析装置に限らず、超音波で解析する方法または情報処理装置に実行させる超音波解析プログラムであってもよい。 The present invention is not limited to an ultrasonic analysis apparatus, but may be a method of analyzing with ultrasonic waves or an ultrasonic analysis program executed by an information processing apparatus.
　本発明によれば、経皮測定で得られた軟骨表面からのエコー信号の特徴量から、軟骨表面に対する超音波信号の入射角度に対する、エコー信号の強度の分布を解析し、軟骨の変性を定量的に解析できる。 According to the present invention, the distribution of the echo signal intensity with respect to the incident angle of the ultrasonic signal to the cartilage surface is analyzed from the feature quantity of the echo signal from the cartilage surface obtained by transcutaneous measurement, and the cartilage degeneration is quantified. Analysis.
実施形態に係る超音波解析システムの構成及び膝関節内部を示す図である。It is a figure showing the composition of the ultrasonic analysis system concerning an embodiment, and the inside of a knee joint. 超音波解析装置のブロック図を示す図である。It is a figure which shows the block diagram of an ultrasonic analyzer. 軟骨表面から反射したエコー信号の強度および超音波の送信とエコー信号の受信の時間差を示す図である。It is a figure which shows the time difference of the intensity | strength of the echo signal reflected from the cartilage surface, and transmission of an ultrasonic wave, and reception of an echo signal. 膝関節の構造および測定箇所を示す図である。It is a figure which shows the structure and measurement location of a knee joint. 各測定位置における外皮から軟骨表面の距離を示す図である。It is a figure which shows the distance of the cartilage surface from the outer skin in each measurement position. 各測定位置における軟骨表面に対する超音波信号の入射角度を示す図である。It is a figure which shows the incident angle of the ultrasonic signal with respect to the cartilage surface in each measurement position. 各測定位置におけるエコー信号の強度を示す図である。It is a figure which shows the intensity | strength of the echo signal in each measurement position. 各測定位置における超音波の入射角度に対応するエコー信号の強度の分布を示す図である。It is a figure which shows distribution of the intensity | strength of the echo signal corresponding to the incident angle of the ultrasonic wave in each measurement position.
　図１は、本発明の超音波解析システムの構成および膝関節内部を示す図である。超音波プローブ１の先端にトランスデューサ２が取り付けられている。超音波プローブ１およびモニタ４は、コンピュータ３に接続される。トランスデューサ２は、被験者の膝に接触されて用いられる。駆動機構６は、超音波プローブ１を、コンピュータ３の指示に基づき、駆動機構６の軸に沿って平行に駆動する。 FIG. 1 is a diagram showing the configuration of the ultrasonic analysis system of the present invention and the inside of a knee joint. A transducer 2 is attached to the tip of the ultrasonic probe 1. The ultrasonic probe 1 and the monitor 4 are connected to the computer 3. The transducer 2 is used in contact with the knee of the subject. The drive mechanism 6 drives the ultrasonic probe 1 in parallel along the axis of the drive mechanism 6 based on instructions from the computer 3.
　超音波プローブ１は、トランスデューサ２の動作を制御する。超音波プローブ１は、コンピュータ３から超音波信号の送信指示を受け取り、トランスデューサ２に送る。トランスデューサ２は、送信指示に基づいて超音波信号を膝軟骨５に向けて照射する。また、トランスデューサ２は、膝軟骨５の表面で反射したエコー信号を受信し、当該エコー信号のレベルに応じた受信信号を超音波プローブ１に送る。超音波プローブ１は、トランスデューサ２から受け取った受信信号をコンピュータ３に送る。超音波解析システムは、駆動機構６が超音波プローブ１を駆動することにより、順次膝軟骨５を測定する。　なお、トランスデューサ２は、本発明の必須の構成ではなく、コンピュータ３からの指示で超音波プローブ１が超音波を送受信する態様であっても良い。 The ultrasonic probe 1 controls the operation of the transducer 2. The ultrasonic probe 1 receives an ultrasonic signal transmission instruction from the computer 3 and sends it to the transducer 2. The transducer 2 irradiates the knee cartilage 5 with an ultrasonic signal based on the transmission instruction. The transducer 2 receives an echo signal reflected from the surface of the knee cartilage 5 and sends a reception signal corresponding to the level of the echo signal to the ultrasonic probe 1. The ultrasonic probe 1 sends the reception signal received from the transducer 2 to the computer 3. The ultrasonic analysis system measures the knee cartilage 5 sequentially by the drive mechanism 6 driving the ultrasonic probe 1. Note that the transducer 2 is not an essential component of the present invention, and the ultrasonic probe 1 may transmit and receive ultrasonic waves according to instructions from the computer 3.
　図２（Ａ）は、コンピュータ３のブロック図である。コンピュータ３は、受信部３０、送信部３１、信号処理部３２、画像処理部３３、および制御部３４から構成される。制御部３４は、受信部３０、送信部３１、信号処理部３２、画像処理部３３、駆動機構６の動作を制御する。 FIG. 2A is a block diagram of the computer 3. The computer 3 includes a receiving unit 30, a transmitting unit 31, a signal processing unit 32, an image processing unit 33, and a control unit 34. The control unit 34 controls operations of the reception unit 30, the transmission unit 31, the signal processing unit 32, the image processing unit 33, and the drive mechanism 6.
　受信部３０は、超音波プローブ１から受信信号を受け取る。受信部３０は、受信信号をＡ／Ｄ変換し、信号処理部３２に送る。送信部３１は、制御部３４の指示に従って送信指示を超音波プローブ１に送る。 The receiving unit 30 receives a reception signal from the ultrasonic probe 1. The receiving unit 30 performs A / D conversion on the received signal and sends it to the signal processing unit 32. The transmission unit 31 sends a transmission instruction to the ultrasonic probe 1 in accordance with an instruction from the control unit 34.
　信号処理部３２は、図２（Ｂ）に示すように、強度検出部３２０、時間差検出部３２１、および解析部３２２から構成される。 The signal processing unit 32 includes an intensity detection unit 320, a time difference detection unit 321, and an analysis unit 322 as shown in FIG.
　図３は、受信信号を示す図である。図３において、横軸は、時間であり、縦軸は、電圧（振幅）である。強度検出部３２０は、受信部３０から得た受信信号の情報（時間ごとの受信信号の電圧）を用いてエコー信号の強度および受信タイミングを検出する。具体的には、強度検出部３２０は、所定の時間内（例えば１００μｓ内）における電圧が最も大きい値をエコー信号の強度とし、最大電圧となったタイミングを受信タイミングとする。例えば、図３におけるエコー信号の強度は、およそ０．４Ｖであり、受信タイミングは、およそ４０μｓ経過したときである。　なお、受信タイミングは、エコー信号の強度が最大電圧となったタイミングに限らず、図３に示すエコー信号の強度の包絡線の最大電圧となるタイミング、または図３に示すエコー信号の強度が所定の閾値以上かつエコー信号の強度の微分値が所定の閾値以上となるタイミングから最も時間が近いゼロクロス点のタイミングとしてもよい。 FIG. 3 is a diagram showing a received signal. In FIG. 3, the horizontal axis represents time, and the vertical axis represents voltage (amplitude). The intensity detection unit 320 detects the intensity of the echo signal and the reception timing using the information on the reception signal obtained from the reception unit 30 (the voltage of the reception signal for each time). Specifically, the intensity detection unit 320 sets the value of the highest voltage within a predetermined time (for example, within 100 μs) as the intensity of the echo signal, and sets the timing when the voltage reaches the maximum as the reception timing. For example, the intensity of the echo signal in FIG. 3 is about 0.4 V, and the reception timing is when about 40 μs has elapsed. Note that the reception timing is not limited to the timing when the intensity of the echo signal reaches the maximum voltage, but the timing when the maximum voltage of the envelope of the intensity of the echo signal shown in FIG. 3 or the intensity of the echo signal shown in FIG. It is good also as the timing of the zero crossing point which is the closest time from the timing when the differential value of the intensity of the echo signal is equal to or greater than a predetermined threshold.
　さらには、強度検出部３２０は、軟骨表面を次の方法で検出して、当該軟骨表面のエコー信号強度と受診タイミングを検出してもよい。 Furthermore, the intensity detecting unit 320 may detect the cartilage surface by the following method, and detect the echo signal intensity and the visit timing of the cartilage surface.
　軟骨表面の検出方法としては、例えば、次の方法が考えられる。膝の表面に超音波プローブ１を当接してエコー信号を受信する。これを第１状態のエコー信号とする。次に、超音波プローブ１を膝の表面に当接させたまま移動し、エコー信号を受信する。これを第２状態のエコー信号とする。 As a method for detecting the cartilage surface, for example, the following method can be considered. The ultrasonic probe 1 is brought into contact with the knee surface to receive an echo signal. This is the echo signal in the first state. Next, the ultrasonic probe 1 is moved in contact with the knee surface, and an echo signal is received. This is the echo signal in the second state.
　超音波プローブ１を膝の表面に当接させたまま移動させても軟骨は動かないが、軟骨表面と膝の表面との間に存在する軟組織は、超音波プローブ１の移動に追随して移動する。したがって、軟組織は第１状態と第２状態とで超音波プローブ１に対する相対位置は変化しないが、軟骨は第１状態と第２状態とで超音波プローブ１に対する相対位置は変化する。 Although the cartilage does not move even if the ultrasonic probe 1 is moved while being in contact with the knee surface, the soft tissue existing between the cartilage surface and the knee surface moves following the movement of the ultrasonic probe 1. To do. Therefore, the relative position of the soft tissue in the first state and the second state does not change in the first state and the second state, but the relative position of the cartilage in the first state and the second state changes in the first state and the second state.
　この原理を利用して、第１状態のエコー信号と第２状態のエコー信号における波形が類似する領域を検出し、当該類似領域と超音波プローブ１との相対的位置関係が第１状態と第２状態とで変化する領域と、変化しない領域との境界を検出する。この境界を、膝軟骨表面として検出する。 Using this principle, a region where the waveforms of the echo signal in the first state and the echo signal in the second state are similar is detected, and the relative positional relationship between the similar region and the ultrasonic probe 1 is the first state and the first state. A boundary between a region that changes in two states and a region that does not change is detected. This boundary is detected as the knee cartilage surface.
　そして、強度検出部３２０は、検出したエコー信号の強度を解析部３２２に、また、エコー信号の強度および受信タイミングを時間差検出部３２１に送る。 Then, the intensity detector 320 sends the detected intensity of the echo signal to the analyzer 322, and sends the intensity of the echo signal and the reception timing to the time difference detector 321.
　制御部３４は、時間差検出部３２１を動作させる際に、送信部３１が送信指示を行ったタイミングを、時間差検出部３２１に送る。そして、時間差検出部３２１は、送信指示を行ったタイミングから受信タイミングまでの時間差を算出する。次に、時間差検出部３２１は、検出した時間差を、解析部３２２に送る。時間差検出部３２１により求められた時間差は、トランスデューサ２（生体表面）から膝軟骨５の表面までの距離に対応する。 When the time difference detection unit 321 is operated, the control unit 34 sends to the time difference detection unit 321 the timing when the transmission unit 31 gives a transmission instruction. Then, the time difference detection unit 321 calculates a time difference from the timing when the transmission instruction is given to the reception timing. Next, the time difference detection unit 321 sends the detected time difference to the analysis unit 322. The time difference obtained by the time difference detection unit 321 corresponds to the distance from the transducer 2 (biological surface) to the surface of the knee cartilage 5.
　時間差検出部３２１から送られた時間差は、超音波がトランスデューサ２（生体表面）から膝軟骨５の表面までを往復する時間である。解析部３２２は、生体表面で超音波信号を照射した点において、検出された時間差に、超音波が生体内部で進行する速度を乗算し、さらに２で除算し、トランスデューサ２（生体表面）から膝軟骨５の表面までの距離を求める。 The time difference sent from the time difference detection unit 321 is the time for the ultrasonic wave to reciprocate from the transducer 2 (biological surface) to the surface of the knee cartilage 5. The analysis unit 322 multiplies the detected time difference at the point where the ultrasonic signal is radiated on the surface of the living body by the speed at which the ultrasonic wave travels inside the living body, and further divides the result by 2 from the transducer 2 (biological surface) to the knee. The distance to the surface of the cartilage 5 is obtained.
　解析部３２２による膝軟骨５の表面に対する超音波信号に入射角度の算出について、図４を用いて、以下、詳細に説明する。 The calculation of the incident angle of the ultrasonic signal to the surface of the knee cartilage 5 by the analysis unit 322 will be described in detail below with reference to FIG.
　図４（Ａ）は、右膝関節を内側から外側に見たときの、膝関節の内部構造を示す図である。図４（Ａ）において、＋Ｚ側は、膝の表側であり、－Ｚ側は、膝の裏側である。図４（Ａ）において、＋Ｙ側は、胴体側であり、－Ｙ側は、足先側である。図４（Ａ）における点線部で占める範囲は、右膝の外皮において、超音波信号を照射する範囲である。コンピュータ３は、超音波プローブ１が図４（Ａ）における線に沿ってスキャンするよう、駆動機構６を制御する。 FIG. 4 (A) is a diagram showing the internal structure of the knee joint when the right knee joint is viewed from the inside to the outside. In FIG. 4A, the + Z side is the front side of the knee, and the −Z side is the back side of the knee. In FIG. 4A, the + Y side is the trunk side, and the -Y side is the toe side. The range occupied by the dotted line in FIG. 4A is a range in which an ultrasonic signal is irradiated on the outer skin of the right knee. The computer 3 controls the drive mechanism 6 so that the ultrasonic probe 1 scans along the line in FIG.
　図４（Ｂ）は、図４（Ａ）の点線部で占める範囲を、＋Ｚ側から―Ｚ側に向けて見たときの図である。Ｘの値が大きくなる方向は、右膝の内側の方向である。各黒点は、超音波信号を照射した位置である。図４（Ｃ）は、図４（Ｂ）の図の一部（四角の実線の範囲）の拡大図である。本実施形態では、説明のために、超音波を照射した範囲を小領域に分けて、番号（Ｌ１乃至Ｌ４）を付している。また、本実施形態では、小領域Ｌ１内の超音波を照射した各点に、番号（Ｎ１乃至Ｎ９）を付している。超音波信号およびエコー信号は、各点で順次スキャンされ、トランスデューサ２によって送受信される。１つの超音波プローブ１で各点を順次スキャンする以外に、複数の超音波プローブ１を用いて、同時にスキャンする態様であっても構わない。 FIG. 4B is a diagram when the range occupied by the dotted line portion in FIG. 4A is viewed from the + Z side toward the −Z side. The direction in which the value of X increases is the direction inside the right knee. Each black dot is a position irradiated with an ultrasonic signal. FIG. 4C is an enlarged view of a part of the diagram in FIG. 4B (the range of the solid line in the square). In the present embodiment, for the sake of explanation, the range irradiated with ultrasonic waves is divided into small areas and numbered (L1 to L4). In the present embodiment, numbers (N1 to N9) are assigned to the points irradiated with the ultrasonic waves in the small region L1. The ultrasonic signal and the echo signal are sequentially scanned at each point and transmitted / received by the transducer 2. In addition to sequentially scanning each point with one ultrasonic probe 1, a plurality of ultrasonic probes 1 may be used for simultaneous scanning.
　まず、解析部３２２は、小領域Ｌ１内のＮ１乃至Ｎ９の各点において、それぞれの点からトランスデューサ２（生体表面）から軟骨表面までの距離を求める。さらに、解析部３２２は、超音波信号の方向ベクトルおよび軟骨表面までの距離から、膝軟骨５の表面における超音波信号が反射した位置を求める。図５（Ａ）は、図４（Ａ）および図４（Ｂ）に示す超音波信号を照射した各位置における、生体表面から膝軟骨５の表面までの深さを示す図である。解析部３２２より求められた膝軟骨５の表面までの距離は、生体表面から膝軟骨５までの深さに相当する。図５（Ａ）は、深さの値が小さいほど、膝軟骨５の表面が生体内部側にあることを示す図である。図５（Ａ）に示す各黒点は、解析部３２２により求められたＭ１乃至Ｍ９である。図５（Ｂ）は、１次元（Ｘ方向）で、各点の深さの値を示した図である。 First, the analysis unit 322 obtains the distance from each point to the cartilage surface from the transducer 2 (biological surface) at each point N1 to N9 in the small region L1. Further, the analysis unit 322 obtains the position where the ultrasonic signal is reflected on the surface of the knee cartilage 5 from the direction vector of the ultrasonic signal and the distance to the cartilage surface. FIG. 5A is a diagram showing the depth from the surface of the living body to the surface of the knee cartilage 5 at each position where the ultrasonic signal shown in FIGS. 4A and 4B is irradiated. The distance to the surface of the knee cartilage 5 obtained from the analysis unit 322 corresponds to the depth from the surface of the living body to the knee cartilage 5. FIG. 5A is a diagram showing that the surface of the knee cartilage 5 is closer to the inside of the living body as the depth value is smaller. The black dots shown in FIG. 5A are M1 to M9 obtained by the analysis unit 322. FIG. 5B is a diagram showing the depth value of each point in one dimension (X direction).
　Ｍ１は、膝軟骨５の表面のうちＮ１から照射された超音波信号が反射した位置である。解析部３２２は、Ｍ１の位置算出と同様に、Ｎ２乃至Ｎ９にそれぞれ対応したＭ２乃至Ｍ９を求める。また、図５（Ｂ）に示す小領域Ｋ１は、Ｍ１乃至Ｍ９からなる面の一部を一次元で表したものであり、Ｍ１乃至Ｍ３を通る曲線部である。 M1 is a position where the ultrasonic signal irradiated from N1 is reflected on the surface of the knee cartilage 5. The analysis unit 322 calculates M2 to M9 corresponding to N2 to N9, respectively, similarly to the calculation of the position of M1. A small region K1 shown in FIG. 5B is a one-dimensional representation of a part of the surface composed of M1 to M9, and is a curved portion passing through M1 to M3.
　解析部３２２は、膝軟骨５の表面の一部の位置（Ｍ１乃至Ｍ９）を求めることにより、膝軟骨５の表面の一部の形状を求めることができる。 The analysis unit 322 can obtain the partial shape of the surface of the knee cartilage 5 by obtaining the position (M1 to M9) of the surface of the knee cartilage 5.
　解析部３２２は、小領域Ｋ１の近似直線を求める。近似直線は、最小二乗法により求められる。すなわち、解析部３２２は、Ｍ１乃至Ｍ３の各点から近似直線までの残差の二乗値を求め、各点について求めた二乗値の総和が最小となるよう、近似平面の法線ベクトルを求める。近似平面の求め方は、最小二乗法に限らない。　なお、解析部３２２は、小領域が二次元（Ｘ軸およびＹ軸からなる面）の場合、小領域の近似平面を求める。 The analysis unit 322 obtains an approximate straight line of the small region K1. The approximate straight line is obtained by the method of least squares. That is, the analysis unit 322 obtains the square value of the residual from each point M1 to M3 to the approximate line, and obtains the normal vector of the approximate plane so that the sum of the square values obtained for each point is minimized. The method of obtaining the approximate plane is not limited to the least square method. Note that the analysis unit 322 obtains an approximate plane of the small region when the small region is two-dimensional (a surface composed of the X axis and the Y axis).
　そして、解析部３２２は、小領域Ｋ１の中央であるＭ２に照射された超音波信号の進行方向ベクトルと、求めた近似直線の法線ベクトルのなす角度を求め、求めた角度を、小領域Ｋ１における、超音波信号の膝軟骨５の表面への入射角度とする。次に、解析部３２２は、Ｎ１乃至Ｎ３において強度検出部３２０が検出したエコー信号の強度の平均値を、小領域Ｋ１における超音波信号の入射角度と対応付ける。 Then, the analysis unit 322 obtains the angle formed by the traveling direction vector of the ultrasonic signal irradiated to M2, which is the center of the small region K1, and the normal vector of the obtained approximate straight line, and the obtained angle is determined as the small region K1. The incidence angle of the ultrasonic signal on the surface of the knee cartilage 5 in FIG. Next, the analysis unit 322 associates the average value of the intensity of the echo signal detected by the intensity detection unit 320 in N1 to N3 with the incident angle of the ultrasonic signal in the small region K1.
　なお、解析部３２２は、小領域が二次元の場合、近似平面の法線ベクトルとＭ１乃至Ｍ９の中央であるＭ５に照射された超音波信号の進行方向ベクトルを用いて、膝軟骨表面への入射角度を求める。また、解析部３２２は、この場合、エコー信号の強度の平均値を、Ｎ１乃至Ｎ９において検出したエコー信号の強度から求める。 When the small region is two-dimensional, the analysis unit 322 uses the normal vector of the approximate plane and the traveling direction vector of the ultrasonic signal irradiated to M5 which is the center of M1 to M9, to the knee cartilage surface. Find the incident angle. Further, in this case, the analysis unit 322 obtains the average value of the echo signal intensity from the intensity of the echo signal detected at N1 to N9.
　制御部３４は、駆動機構６を制御し、Ｋ１以外の小領域においても、強度検出部３２０および時間差検出部３２１に、エコー信号の強度および時間差を、検出させる。そして、制御部３４は、解析部３２２に、各小領域におけるエコー信号の強度の平均値を、当該小領域における超音波信号の入射角度に、対応付けさせる。 The control unit 34 controls the drive mechanism 6 to cause the intensity detection unit 320 and the time difference detection unit 321 to detect the intensity and time difference of the echo signal even in a small region other than K1. Then, the control unit 34 causes the analysis unit 322 to associate the average value of the echo signal intensity in each small region with the incident angle of the ultrasonic signal in the small region.
　図６は、図４（Ａ）および図４（Ｂ）に示す超音波信号を照射した各位置における、超音波信号の膝軟骨５の表面に対する入射角度を示す図である。図７は、図４（Ａ）および図４（Ｂ）に示す超音波信号を照射した各位置における、エコー信号の強度を示す図である。 FIG. 6 is a diagram showing an incident angle of the ultrasonic signal with respect to the surface of the knee cartilage 5 at each position irradiated with the ultrasonic signal shown in FIGS. 4 (A) and 4 (B). FIG. 7 is a diagram showing the intensity of the echo signal at each position irradiated with the ultrasonic signal shown in FIGS. 4 (A) and 4 (B).
　以上のように、解析部３２２は、超音波信号の入射角度に対するエコー信号の平均強度の分布を作成する。そして、解析部３２２は、作成した当該分布に対して、統計的な解析をする。 As described above, the analysis unit 322 creates the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal. Then, the analysis unit 322 performs statistical analysis on the created distribution.
　解析部３２２は、統計的解析のため、超音波信号の入射角度に対するエコー信号の平均強度の分布の回帰直線を、例えば最小二乗法によって求める。回帰直線の傾きの絶対値は、エコー信号の強度が超音波信号の入射角度に依存する度合いである。したがって、解析部３２２は、当該依存する度合いを、定量的な値として、求めることができる。 The analysis unit 322 obtains a regression line of the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal, for example, by a least square method for statistical analysis. The absolute value of the slope of the regression line is a degree that the intensity of the echo signal depends on the incident angle of the ultrasonic signal. Therefore, the analysis unit 322 can obtain the degree of dependence as a quantitative value.
　最後に、解析部３２２は、解析結果を、画像処理部３３に送る。解析結果は、生体表面の複数の位置の各位置における、膝軟骨５の表面までの距離および超音波信号の入射角度、超音波信号の入射角度に対するエコー信号の平均強度の分布、および当該分布の回帰直線である。 Finally, the analysis unit 322 sends the analysis result to the image processing unit 33. The analysis result shows that the distance to the surface of the knee cartilage 5 and the incident angle of the ultrasonic signal, the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal, and the distribution It is a regression line.
　画像処理部３３は、解析部３２２から受け取った解析結果を、２次元グラフで表示する画像を生成し、モニタ４に送る。そして、制御部３４は、モニタ４に、当該画像を表示させる。したがって、測定者は、解析結果を視覚的に認識することができる。モニタ４は、本発明において、必須の構成ではなく、印刷手段によって解析結果が印刷される態様であっても構わない。 The image processing unit 33 generates an image for displaying the analysis result received from the analysis unit 322 as a two-dimensional graph, and sends the image to the monitor 4. Then, the control unit 34 causes the monitor 4 to display the image. Therefore, the measurer can visually recognize the analysis result. The monitor 4 is not an essential component in the present invention, and may be an aspect in which an analysis result is printed by a printing unit.
　図８は、モニタ４に表示される画像を示す図である。図８（Ａ）および図８（Ｂ）は、横軸を超音波信号の入射角度とし、縦軸がエコー信号の強度とし、エコー信号の平均強度および超音波信号の入射角度からなる複数のデータをプロット（小領域Ｌ１におけるデータ等）した図である。図８（Ａ）は、正常な軟骨の解析結果を示す図である。図８（Ｂ）は、変性した軟骨の解析結果を示す図である。図８（Ａ）では、回帰直線の傾きの絶対値が０．９であり、図８（Ｂ）では、回帰直線の傾きの絶対値０．１である。すなわち、正常な軟骨に対するエコー信号の強度は、図８（Ａ）に示すように、回帰直線の傾きの絶対値が０．９と大きいため、角度依存性がある。一方、変性した軟骨に対するエコー信号の強度は、回帰直線の傾きの絶対値が０．１と、正常な軟骨の回帰直線の傾きの絶対値より小さいため、角度依存性がない。 FIG. 8 is a diagram showing an image displayed on the monitor 4. 8A and 8B, the horizontal axis represents the incident angle of the ultrasonic signal, the vertical axis represents the intensity of the echo signal, and a plurality of data including the average intensity of the echo signal and the incident angle of the ultrasonic signal. Is plotted (data and the like in the small region L1). FIG. 8A is a diagram showing the analysis result of normal cartilage. FIG. 8B is a diagram showing the analysis result of denatured cartilage. In FIG. 8A, the absolute value of the slope of the regression line is 0.9, and in FIG. 8B, the absolute value of the slope of the regression line is 0.1. That is, the intensity of the echo signal for normal cartilage is angle-dependent because the absolute value of the slope of the regression line is as large as 0.9 as shown in FIG. On the other hand, since the absolute value of the slope of the regression line is 0.1, which is smaller than the absolute value of the slope of the normal cartilage regression line, the intensity of the echo signal for the degenerated cartilage has no angle dependency.
　測定者は、モニタ４に表示される図８（Ａ）または図８（Ｂ）の回帰直線の傾きの絶対値により、軟骨の変性している度合いを定量的に知ることができる。 The measurer can quantitatively know the degree of cartilage degeneration based on the absolute value of the slope of the regression line shown in FIG. 8A or 8B displayed on the monitor 4.
　また、解析部３２２は、図８（Ａ）の回帰直線の傾きの絶対値と比べ、図８（Ｂ）の回帰直線の傾きの絶対値が小さいことから、図８（Ｂ）に示すように解析された軟骨の方がより変性していると判断する。このように、測定者は、超音波解析システムに、左膝軟骨と右膝軟骨を解析させることにより、どちらの膝軟骨がより変性しているか判断することができる。 Further, the analysis unit 322 has a smaller absolute value of the slope of the regression line of FIG. 8B than the absolute value of the slope of the regression line of FIG. 8A, so that as shown in FIG. Judge that the analyzed cartilage is more denatured. Thus, the measurer can determine which knee cartilage is more denatured by causing the ultrasonic analysis system to analyze the left knee cartilage and the right knee cartilage.
　また、超音波解析システムの解析部３２２は、回帰直線の傾きの絶対値が所定の閾値より小さい場合、解析した軟骨が変性していると判断する。例えば、所定の閾値を０．５とした場合、解析部３２２は、図８（Ａ）に示す例では、近似直線の傾きが０．９と閾値より大きく、正常な軟骨と判断する。一方、解析部３２２は、図８（Ｂ）に示す例では、回帰直線の傾きの絶対値が０．１と閾値より小さく、変性した軟骨と判断する。また、解析部３２２は、この判断結果を、画像処理部３３に送り、そして、制御部３４は、モニタ４に、その画像を表示させることができる。また、所定の閾値は、１つに限らず、複数あっても良い。解析部３２２は、複数の所定の閾値を用いる場合、軟骨の変性を、段階的に、例えば、正常、やや変性、かなり変性、即治療要のうちいずれかの段階と、判断することができる。他にも、解析部３２２は、回帰直線の傾きの絶対値を正常度合い（例えば傾きの絶対値が０．９であれば正常度９０％）として、軟骨の変性度合を判断することができる。 Also, the analysis unit 322 of the ultrasonic analysis system determines that the analyzed cartilage is degenerated when the absolute value of the slope of the regression line is smaller than a predetermined threshold value. For example, when the predetermined threshold value is 0.5, in the example shown in FIG. 8A, the analysis unit 322 determines that the slope of the approximate line is 0.9, which is larger than the threshold value, and is normal cartilage. On the other hand, in the example shown in FIG. 8B, the analysis unit 322 determines that the absolute value of the slope of the regression line is 0.1, which is smaller than the threshold, and is degenerated cartilage. The analysis unit 322 sends the determination result to the image processing unit 33, and the control unit 34 can display the image on the monitor 4. Further, the predetermined threshold value is not limited to one and may be plural. When a plurality of predetermined threshold values are used, the analysis unit 322 can determine the degeneration of the cartilage in a stepwise manner, for example, one of normal, slightly denatured, considerably denatured, and immediate treatment required. In addition, the analysis unit 322 can determine the degree of cartilage degeneration using the absolute value of the slope of the regression line as the normal degree (for example, the normality is 90% when the absolute value of the slope is 0.9).
　制御部３４は、モニタ４に、図８だけでなく、図５乃至図７も解析結果として表示させることができる。本発明は、表示された図５乃至図８から、変性度を測定者自身で判断する態様であっても良い。 The control unit 34 can cause the monitor 4 to display not only FIG. 8 but also FIGS. 5 to 7 as analysis results. The present invention may be an embodiment in which the degree of modification is determined by the measurer himself from the displayed FIGS.
　以上のように、本発明の超音波解析システムは、膝軟骨５が変性している度合いを、回帰直線の傾きの絶対値を算出することにより、定量的に解析することができる。また、測定者は、解析結果がモニタ４で表示されることにより、定量的な解析結果を認識することができる。 As described above, the ultrasonic analysis system of the present invention can quantitatively analyze the degree of degeneration of the knee cartilage 5 by calculating the absolute value of the slope of the regression line. Further, the measurer can recognize the quantitative analysis result by displaying the analysis result on the monitor 4.
　なお、上記の例の駆動機構６は、本発明の必須の構成ではない。手作業により、超音波照射位置を移動させ、複数の位置において測定する態様であっても構わない。 The drive mechanism 6 in the above example is not an essential configuration of the present invention. The ultrasonic irradiation position may be moved manually to measure at a plurality of positions.
　なお、上記の例の強度検出部３２０は、受信部３０から送信されたデジタルデータを処理しているが、この態様に限らない。受信部３０からアナログの受信信号を強度検出部３２０が受け取り、当該受信信号を処理する態様であっても良い。 In addition, although the intensity | strength detection part 320 of said example processes the digital data transmitted from the receiving part 30, it is not restricted to this aspect. An aspect may be possible in which the intensity detection unit 320 receives an analog reception signal from the reception unit 30 and processes the reception signal.
　また、本発明の超音波解析システムは、可搬性に優れる、超音波プローブ１及びモニタ４がコンピュータ３に一体に構成される態様であっても構わない。 Further, the ultrasonic analysis system of the present invention may be an aspect in which the ultrasonic probe 1 and the monitor 4 are excellently portable and configured integrally with the computer 3.
　上記の例では、超音波信号の入射角度に対するエコー信号の平均強度の分布の解析として、回帰直線の傾きの絶対値を求めているが、エコー信号の平均強度および膝軟骨５に対する超音波信号の入射角度の相関係数を求めて解析しても良い。解析部３２２は、軟骨の変性度合の解析のために相関係数を算出場合、相関係数が―１（負相関）に近い値ほど、正常な軟骨と判断し、相関係数が０（無相関）に近い値であれば、軟骨が変性していると判断する。 In the above example, as an analysis of the distribution of the average intensity of the echo signal with respect to the incident angle of the ultrasonic signal, the absolute value of the slope of the regression line is obtained, but the average intensity of the echo signal and the ultrasonic signal for the knee cartilage 5 are calculated. The correlation coefficient of the incident angle may be obtained and analyzed. When calculating the correlation coefficient for analyzing the degree of cartilage degeneration, the analysis unit 322 determines that the correlation coefficient is closer to −1 (negative correlation) as normal cartilage, and the correlation coefficient is 0 (none). If the value is close to (correlation), it is determined that the cartilage is degenerated.
　なお、上記の例では、時間差検出部３２１が検出した時間差に超音波の進行速度を乗算し、膝軟骨５の表面までの距離を求めているが、図５に示すように、測定者が視覚的に認識できるために距離を求めているにすぎない。本発明は、トランスデューサ２から膝軟骨５の表面までの距離を求めなくても軟骨の表面状態を解析できる。すなわち、解析部３２２は、Ｘ軸、Ｙ軸、および時間差軸からなる空間における近似平面を求め、その近似平面の傾斜角度を超音波信号の入射角度として、当該入射角度とエコー信号の平均強度との相関関係を解析しても良い。また、コンピュータ３に接続されるキーボードを通じて、測定者が入射角度を手入力し、解析部３２２に与える態様であっても良い。 In the above example, the time difference detected by the time difference detection unit 321 is multiplied by the ultrasonic traveling speed to obtain the distance to the surface of the knee cartilage 5. However, as shown in FIG. The distance is only calculated because it can be recognized. The present invention can analyze the surface state of the cartilage without obtaining the distance from the transducer 2 to the surface of the knee cartilage 5. That is, the analysis unit 322 obtains an approximate plane in the space composed of the X axis, the Y axis, and the time difference axis, and uses the inclination angle of the approximate plane as the incident angle of the ultrasonic signal, and the incident angle and the average intensity of the echo signal The correlation may be analyzed. Alternatively, the measurement person may manually input the incident angle through a keyboard connected to the computer 3 and give the incident angle to the analysis unit 322.
　また、上記の例では３点から近似直線を算出したが（近似平面は９点を用いて算出）、３点に限らない。 In the above example, the approximate straight line is calculated from 3 points (the approximate plane is calculated using 9 points), but is not limited to 3 points.
　本実施例のエコー信号の強度の単位は、図８（Ａ）および図８（Ｂ）に示すように、ｄＢを用いているが、電圧の単位であるＶｏｌｔでもよい。しかし、エコー信号の電圧の絶対値は、生体表面から膝軟骨５の表面までの軟部組織が厚い被験者の場合、小さく、その変化量の絶対値も小さいため、解析しても回帰直線の傾きの絶対値に有意な差が表れにくくなる。一方、回帰直線の傾きの絶対値は、エコー信号の強度の単位をｄＢにすると、エコー信号の電圧が低く検出されても、相対的な値に変換されるため、有意な差となる。 The unit of the intensity of the echo signal of this embodiment is dB as shown in FIGS. 8A and 8B, but may be Volt which is a unit of voltage. However, the absolute value of the voltage of the echo signal is small for a subject with a thick soft tissue from the surface of the living body to the surface of the knee cartilage 5, and the absolute value of the amount of change is also small. Significant differences in absolute values are less likely to appear. On the other hand, when the unit of the intensity of the echo signal is dB, the absolute value of the slope of the regression line is a significant difference because it is converted to a relative value even if the echo signal voltage is detected low.
１…超音波プローブ
２…トランスデューサ
３…コンピュータ
４…モニタ
５…膝軟骨
６…駆動機構
３０…受信部
３１…送信部
３２…信号処理部
３３…画像処理部
３４…制御部
３２０…強度検出部
３２１…時間差検出部
３２２…解析部 DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe 2 ... Transducer 3 ... Computer 4 ... Monitor 5 ... Knee cartilage 6 ... Drive mechanism 30 ... Reception part 31 ... Transmission part 32 ... Signal processing part 33 ... Image processing part 34 ... Control part 320 ... Intensity detection part 321 ... Time difference detector 322 ... Analyzer

Claims (15)

  1. 　超音波信号を送信し、生体内部で反射したエコー信号を受信する送受信部と、
    　前記エコー信号の強度を検出する強度検出部と、を備えた、超音波解析装置であって、
    　前記超音波信号の前記生体内部に存する軟骨の表面に対する入射角度に対する前記エコー信号の強度の分布、に基づいて前記軟骨の表面状態を解析する解析部、
    　を備えたことを特徴とする超音波解析装置。     A transmission / reception unit for transmitting an ultrasonic signal and receiving an echo signal reflected inside the living body;
    An ultrasonic analysis device comprising an intensity detection unit that detects the intensity of the echo signal,
    An analysis unit for analyzing a surface state of the cartilage based on an intensity distribution of the echo signal with respect to an incident angle with respect to a surface of the cartilage existing inside the living body of the ultrasonic signal;
    An ultrasonic analysis apparatus comprising:
  2. 　前記強度検出部は、
    　前記送受信部に対する軟組織と軟骨の位置関係が異なる複数の状態で得たエコー信号を比較し、前記複数の状態のエコー信号の波形が最も類似する領域の前記送受信部に対する相対位置の変化から軟骨表面を検出し、前記エコー信号のうち前記軟骨表面で反射したエコー信号の強度を検出することを特徴とする請求項１に記載の超音波解析装置。     The intensity detector
    Compares echo signals obtained in a plurality of states in which the positional relationship between soft tissue and cartilage is different with respect to the transmission / reception unit, and determines the cartilage surface from a change in relative position with respect to the transmission / reception unit in a region where the waveforms of the echo signals in the plurality of states are most similar The ultrasonic analysis apparatus according to claim 1, wherein the intensity of an echo signal reflected from the cartilage surface of the echo signal is detected.
  3. 　請求項１または請求項２に記載の超音波解析装置であって、さらに、
    　生体表面の互いに異なる位置でそれぞれ送信された超音波信号の送信タイミングから、各超音波信号に基づいてそれぞれ検出した前記エコー信号の受信タイミングまでの時間差を検出する時間差検出部を備え、
    　前記送受信部は、前記互いに異なる位置において、前記超音波信号を送信し、前記エコー信号を受信し、
    　前記解析部は、前記互いに異なる位置における時間差検出結果に基づいて前記入射角度を算出することを特徴とする超音波解析装置。     The ultrasonic analysis apparatus according to claim 1 or 2, further comprising:
    A time difference detection unit for detecting a time difference from the transmission timing of ultrasonic signals transmitted at different positions on the surface of the living body to the reception timing of the echo signal detected based on each ultrasonic signal;
    The transmitting / receiving unit transmits the ultrasonic signal at the different positions, receives the echo signal,
    The ultrasonic analysis apparatus, wherein the analysis unit calculates the incident angle based on time difference detection results at the different positions.
  4. 　請求項３に記載の超音波解析装置であって、
    　前記解析部は、前記互いに異なる位置における各位置の前記時間差に基づいて前記軟骨の表面の近似面を求め、前記入射角度を算出する、
    　ことを特徴とする超音波解析装置。     The ultrasonic analysis apparatus according to claim 3,
    The analysis unit obtains an approximate surface of the surface of the cartilage based on the time difference between the positions at the different positions, and calculates the incident angle;
    An ultrasonic analyzer characterized by that.
  5. 　請求項１または請求項２に記載の超音波解析装置であって、
    　前記時間差検出部の検出結果に基づいて前記生体表面から前記軟骨表面までの各距離を算出する距離検出部を備え、
    　前記解析部は、前記互いに異なる位置における前記各距離に基づいて前記入射角度を算出する、ことを特徴とする超音波解析装置。     The ultrasonic analysis apparatus according to claim 1 or 2, wherein
    A distance detection unit that calculates each distance from the living body surface to the cartilage surface based on the detection result of the time difference detection unit;
    The ultrasonic analysis apparatus, wherein the analysis unit calculates the incident angle based on the distances at the different positions.
  6. 　請求項１乃至請求項５のいずれかの請求項に記載の超音波解析装置であって、
    　前記送受信部は、前記生体表面を順次スキャンして、生体表面の互いに異なる位置の各位置において、超音波信号を送信し、エコー信号を受信する、超音波解析装置。     The ultrasonic analyzer according to any one of claims 1 to 5, wherein
    The transmitting / receiving unit sequentially scans the surface of the living body, transmits an ultrasonic signal at each of different positions on the surface of the living body, and receives an echo signal.
  7. 　請求項１乃至請求項５のいずれかに記載の超音波解析装置であって、
    　前記送受信部は複数設けられ、
    　各送受信部は、生体表面の互いに異なる位置の各位置において、超音波信号を送信し、エコー信号を受信する、超音波解析装置。     An ultrasonic analyzer according to any one of claims 1 to 5,
    A plurality of the transmission / reception units are provided,
    Each transmitting / receiving unit transmits an ultrasonic signal and receives an echo signal at each of different positions on the surface of a living body.
  8. 　請求項１乃至請求項７のいずれかに記載の超音波解析装置であって、
    　前記解析部は、前記入射角度に対する前記強度の分布の回帰直線の傾きに基づき前記軟骨の表面の変性を解析することを特徴とする、超音波解析装置。     An ultrasonic analyzer according to any one of claims 1 to 7,
    The ultrasonic analysis apparatus, wherein the analysis unit analyzes the degeneration of the surface of the cartilage based on a slope of a regression line of the intensity distribution with respect to the incident angle.
  9. 　請求項８に記載の超音波解析装置であって、
    　前記解析部は、前記回帰直線の傾きの絶対値が小さいほど前記軟骨の表面が変性していると判断することを特徴とする、超音波解析装置。     The ultrasonic analyzer according to claim 8,
    The ultrasonic analysis apparatus, wherein the analysis unit determines that the surface of the cartilage is denatured as the absolute value of the slope of the regression line is smaller.
  10. 　請求項８に記載の超音波解析装置であって、
    　前記解析部は、前記入射角度に対する前記回帰直線の傾きの絶対値が所定の閾値より小さいと、前記軟骨の表面が変性していると判断することを特徴とする、超音波解析装置。     The ultrasonic analyzer according to claim 8,
    The ultrasonic analysis apparatus, wherein the analysis unit determines that the surface of the cartilage is denatured when an absolute value of an inclination of the regression line with respect to the incident angle is smaller than a predetermined threshold value.
  11. 　請求項１乃至請求項１０のいずれかの請求項に記載の超音波解析装置と、
    　前記解析部の解析結果を表示する表示部と、を備えた超音波解析システム。     The ultrasonic analyzer according to any one of claims 1 to 10,
    An ultrasonic analysis system comprising: a display unit that displays an analysis result of the analysis unit.
  12. 　超音波信号を送信し、かつ生体内部で反射したエコー信号を受信する送受信ステップと、
    　前記送受信ステップで受信したエコー信号の強度を検出する強度検出ステップと、
    　を実行する超音波解析方法であって、さらに、
    　前記超音波信号の前記生体内部に存する軟骨の表面に対する入射角度に対する前記エコー信号の強度の分布、に基づいて前記軟骨の表面状態を解析する解析ステップ、
    　を実行することを特徴とする超音波解析方法。     A transmission / reception step of transmitting an ultrasonic signal and receiving an echo signal reflected inside the living body;
    An intensity detection step for detecting the intensity of the echo signal received in the transmission / reception step;
    An ultrasonic analysis method for performing
    An analysis step of analyzing a surface state of the cartilage based on an intensity distribution of the echo signal with respect to an incident angle with respect to a surface of the cartilage existing inside the living body of the ultrasonic signal;
    The ultrasonic analysis method characterized by performing.
  13. 　前記強度検出ステップは、
    　前記送受信部に対する軟組織と軟骨と位置関係が異なる複数の状態で得たエコー信号を比較し、前記複数の状態のエコー信号の波形が最も類似する領域の前記送受信部に対する相対位置の変化から軟骨表面を検出し、前記エコー信号のうち前記軟骨表面で反射したエコー信号の強度を検出することを特徴とする請求項１２に記載の超音波解析方法。     The intensity detection step includes
    Compares echo signals obtained in a plurality of states with different positional relationships between soft tissue and cartilage with respect to the transmitting / receiving unit, and changes the relative position with respect to the transmitting / receiving unit in regions where the waveforms of the echo signals in the plurality of states are most similar to each other. The ultrasonic analysis method according to claim 12, wherein the intensity of an echo signal reflected from the cartilage surface of the echo signal is detected.
  14. 　請求項１２または請求項１３に記載の超音波解析方法であって、
    　前記送受信ステップは、生体表面の互いに異なる位置において、前記超音波信号を送信し、かつ前記エコー信号を受信するステップを含み、
    　生体表面の互いに異なる位置でそれぞれ送信された超音波信号の送信タイミングから、各超音波信号に基づいてそれぞれ検出した前記エコー信号の受信タイミングまでの時間差を検出する時間差検出ステップと、
    　前記互いに異なる位置における時間差検出結果に基づいて前記入射角度を算出する入射角度算出ステップと、を実行することを特徴とする超音波解析方法。     The ultrasonic analysis method according to claim 12 or 13, wherein:
    The transmitting / receiving step includes the steps of transmitting the ultrasonic signal and receiving the echo signal at different positions on the living body surface,
    A time difference detection step for detecting a time difference from the transmission timing of the ultrasonic signals respectively transmitted at different positions on the surface of the living body to the reception timing of the echo signal detected based on each ultrasonic signal;
    An ultrasonic angle analysis method comprising: performing an incident angle calculation step of calculating the incident angle based on the time difference detection results at the different positions.
  15. 　超音波信号を送信し、かつ生体内部で反射したエコー信号を受信する送受信ステップと、
    　前記送受信ステップで受信したエコー信号の強度を検出する強度検出ステップと、
    　を情報処理装置に実行させるプログラムであって、
    　前記送受信ステップは、生体表面の互いに異なる位置において、前記超音波信号を送信し、かつ前記エコー信号を受信するステップを含み、
    　前記互いに異なる位置でそれぞれ送信された超音波信号の送信タイミングから、各超音波信号に基づいてそれぞれ検出した前記エコー信号の受信タイミングまでの時間差を検出する時間差検出ステップと、
    　前記互いに異なる位置における時間差検出結果に基づいて前記入射角度を算出し、前記入射角度に対する前記強度検出ステップで検出した前記エコー信号の強度の分布、に基づいて軟骨の表面状態を解析する解析ステップと、
    　を情報処理装置に実行させることを特徴とするプログラム。     A transmission / reception step of transmitting an ultrasonic signal and receiving an echo signal reflected inside the living body;
    An intensity detection step for detecting the intensity of the echo signal received in the transmission / reception step;
    Is a program that causes an information processing apparatus to execute
    The transmitting / receiving step includes the steps of transmitting the ultrasonic signal and receiving the echo signal at different positions on the living body surface,
    A time difference detection step of detecting a time difference from the transmission timing of the ultrasonic signals transmitted at different positions to the reception timing of the echo signal detected based on each ultrasonic signal;
    An analysis step of calculating the incident angle based on the time difference detection results at the different positions, and analyzing the surface state of the cartilage based on the intensity distribution of the echo signal detected in the intensity detection step with respect to the incident angle; ,
    A program characterized by causing an information processing apparatus to execute.
PCT/JP2013/074306 2012-09-19 2013-09-10 Ultrasonic analysis device, ultrasonic analysis method, and program WO2014045925A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014136133A (en) * 2013-01-18 2014-07-28 Yamaguchi Univ Ultrasonic diagnostic apparatus
WO2017094397A1 (en) * 2015-12-04 2017-06-08 古野電気株式会社 Ultrasonic wave analyzing device, ultrasonic wave analyzing method, and ultrasonic wave analyzing program
JP2018051040A (en) * 2016-09-29 2018-04-05 コニカミノルタ株式会社 Ultrasound diagnostic apparatus and image synthesis method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011050555A (en) * 2009-09-01 2011-03-17 Furuno Electric Co Ltd Ultrasonic bone analyzing device
JP2012105838A (en) * 2010-11-18 2012-06-07 Furuno Electric Co Ltd Device, method and program for analyzing cartilage by using ultrasonic wave

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008050333A2 (en) * 2006-10-24 2008-05-02 Mindelis, Gesel 3d quantitative ultrasonic method for bone inspection and device for its implementation
WO2008108054A1 (en) * 2007-03-05 2008-09-12 Yamaguchi University Ultrasonograph

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011050555A (en) * 2009-09-01 2011-03-17 Furuno Electric Co Ltd Ultrasonic bone analyzing device
JP2012105838A (en) * 2010-11-18 2012-06-07 Furuno Electric Co Ltd Device, method and program for analyzing cartilage by using ultrasonic wave

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014136133A (en) * 2013-01-18 2014-07-28 Yamaguchi Univ Ultrasonic diagnostic apparatus
WO2017094397A1 (en) * 2015-12-04 2017-06-08 古野電気株式会社 Ultrasonic wave analyzing device, ultrasonic wave analyzing method, and ultrasonic wave analyzing program
JPWO2017094397A1 (en) * 2015-12-04 2018-09-20 古野電気株式会社 Ultrasonic analysis apparatus, ultrasonic analysis method, and ultrasonic analysis program
CN108601584A (en) * 2015-12-04 2018-09-28 古野电气株式会社 Ultrasonic wave resolver, ultrasonic wave analytic method and ultrasonic wave analysis program
CN108601584B (en) * 2015-12-04 2021-05-28 古野电气株式会社 Ultrasonic analysis device, ultrasonic analysis method, and storage medium
JP2018051040A (en) * 2016-09-29 2018-04-05 コニカミノルタ株式会社 Ultrasound diagnostic apparatus and image synthesis method

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