JPWO2013124946A1 - Biological blood vessel diameter continuous measurement device - Google Patents

Abstract

A biological blood vessel diameter continuous measuring device capable of continuously measuring a blood vessel diameter even when body motion occurs. Displacement of the feature point region R around the plurality of feature points P between the short-axis images repeatedly generated based on the ultrasonic reflection signal is sequentially obtained by pattern matching, and the blood vessel 12 is obtained from the displacement of the plurality of feature point regions R. The diameter change amount of the blood vessel is sequentially calculated, and the time-series change of the blood vessel diameter is measured based on the diameter change amount of the blood vessel 12, so that the living body can be detected from the short-axis image that is not easily affected by the displacement of the ultrasonic sensor due to body movement or the like. A time-series change in the diameter of the blood vessel is obtained.

Description

  The present invention relates to a living body blood vessel diameter continuous measuring apparatus that continuously measures the blood vessel diameter of a blood vessel located in a living body by bringing an ultrasonic sensor into contact with the living body.

  An ultrasonic sensor is brought into contact with a living body, an ultrasonic radiation signal is transmitted from the ultrasonic sensor, and blood vessel diameters such as a blood vessel diameter and a lumen diameter in the living body are continuously measured. The measurement of the diameter of the blood vessel is a time difference process between ultrasonic reflected signals reflected from the boundary due to a difference in propagation speed between the blood vessel and other tissues, or a distance measurement on an ultrasonic image synthesized from the reflected signal, etc. It is executed by.

  In order to accurately measure the diameter of the blood vessel located in the living body, it is necessary to prevent relative movement of the blood vessel with respect to the ultrasonic sensor brought into contact with the living body, for example, the skin. A mounting table or an upper limb holding device that can fix the upper limb in a predetermined posture is used. For example, the upper limb holding device shown in Patent Document 1 is the vascular endothelial function testing device.

JP 2007-61182 A

  By the way, in the continuous measurement of the blood vessel diameter as described above, in general, the peak value of the ultrasonic reflection signal from the blood vessel after detection obtained using an ultrasonic array positioned along the longitudinal direction of the blood vessel is used. A B-mode image representing an A-mode waveform or an ultrasonic reflection signal, which is an envelope signal to be connected, is used as light and dark, and the peak value of the A-mode waveform or the rising position or the edge position of the blood vessel in the B-mode image The blood vessel diameter is sequentially measured based on the time difference and the sound speed. Measurements with a long-axis cross-section where the ultrasound reflection point of the blood vessel is linear are more measurable compared to measurements with a short-axis cross-section where the ultrasound reflection point of the blood vessel is dotted. is there. However, even if a device that fixes a part of the living body such as the upper limb holding device that can maintain a stable measurement state is used, if the body movement of the measurement subject occurs, the ultrasonic sensor and the blood vessel There is a shift in the relative position, and at least a section in which continuous measurement of the blood vessel diameter is impossible occurs. Even if the position of the ultrasonic sensor is automatically controlled with respect to the blood vessel, measurement cannot be performed from the time when the body motion occurs to the return to the normal position.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a biological blood vessel diameter continuous measuring apparatus capable of continuously measuring a blood vessel diameter even when an ultrasonic sensor is displaced with respect to the blood vessel. It is to provide.

  The present inventors have made various studies on the background of the above circumstances, and as a result, even when the relative position between the ultrasonic sensor and the blood vessel is shifted and a long-axis image cannot be obtained, the blood vessel short-axis image obtained in the cross-sectional image is obtained. If the feature points in the image are tracked by pattern matching using optical flow analysis, the amount of movement of the feature points can be measured for each beat, and the change amount of the blood vessel diameter is sequentially obtained from the amount of movement of the feature points. I found that I could do it. The present invention has been made based on this finding.

  In other words, the living body blood vessel diameter continuous measuring apparatus according to the first aspect of the invention for achieving the above object comprises: (a) continuously measuring the blood vessel diameter of a blood vessel in the living body by bringing the ultrasonic sensor into contact with the living body; (B) a short-axis image generating unit that repeatedly generates a short-axis image of the blood vessel based on an ultrasonic reflection signal detected by the ultrasonic sensor; Displacement calculation unit for sequentially calculating displacement of a plurality of feature point areas between short axis images repeatedly generated by the short axis image generation unit using pattern matching for detecting an area that matches the pattern of the feature point area And (d) a blood vessel diameter displacement amount calculation unit that calculates a displacement amount of the blood vessel from a displacement of a blood vessel radial direction component of the feature point region calculated by the displacement calculation unit, and (e) the blood vessel diameter displacement amount The diameter change of the blood vessel calculated by the calculation unit The vascular diameter measuring unit for measuring time-series change of blood vessel diameter on the basis of the amount, characterized in that it comprises.

  According to the biological blood vessel diameter continuous measurement apparatus of the present invention, displacements of a plurality of feature point regions between short-axis images repeatedly generated based on an ultrasonic reflection signal are sequentially obtained by pattern matching, and the plurality of feature points The blood vessel diameter displacement amount is sequentially calculated from the displacement of the blood vessel radial direction component of the region, and the time-series change of the blood vessel diameter is measured based on the blood vessel radial displacement amount. For this reason, a time-series change in the diameter of the blood vessel of the living body can be obtained from a short-axis image that is not easily affected by the displacement of the ultrasonic sensor due to body movement or the like.

  Here, preferably, it includes an end-diastolic timing signal generator that generates an end-diastolic heartbeat synchronization signal that periodically indicates the end diastole by differentiating the radial displacement amount of the blood vessel that exhibits pulsation by being sequentially obtained. . Therefore, for example, the blood vessel diameter displacement amount calculation unit calculates the diameter displacement of the blood vessel from the displacement of the blood vessel radial direction component synchronized with the end-diastolic heartbeat synchronization signal among the displacement of the feature point region calculated by the displacement calculation unit. The blood vessel diameter measuring unit determines a diameter change amount for each beat in synchronization with the end-diastolic heartbeat synchronization signal, and determines the blood vessel diameter in time series from the diameter change amount for each beat. To do. Therefore, there is an advantage that it is not necessary to use an electrocardiographic signal detection device that detects an ECG signal as the end diastole timing signal.

  Preferably, the ultrasonic sensor is a short-axis ultrasonic array probe arranged so as to be orthogonal to the blood vessel, and a long-axis ultrasonic array probe arranged in a direction parallel to the blood vessel. And a long-axis blood vessel diameter calculating unit that sequentially calculates a blood vessel diameter on the long axis based on an ultrasonic reflection signal from the ultrasonic array probe for long axes, and the short-axis image generating unit includes: The short-axis image of the blood vessel is repeatedly generated based on the ultrasonic reflection signal detected by the short-axis ultrasonic array probe, and the blood vessel diameter measuring unit is calculated by the long-axis blood vessel diameter calculating unit When the measured time-series change of the blood vessel diameter is used as the blood vessel diameter measurement value, and there is a blank section in which the time-series change of the blood vessel diameter cannot be obtained or when all are blank sections, the blood vessel diameter displacement amount Displacement of blood vessel radial direction component of feature point region in short axis image by calculation unit Since the time-series change of the blood vessel diameter in the blank section is generated using the calculated diameter displacement amount of the blood vessel, the blood vessel is lost due to the displacement of the long-axis ultrasonic array probe due to body movement or the like. Even in this case, it is possible to measure the diameter change amount of the blood vessel continuously in time series.

  Preferably, an A mode waveform that is an envelope signal connecting the peak values of the detection waveform of the ultrasonic reflection signal is generated based on the ultrasonic reflection signal from the long axis ultrasonic array probe. Including a mode waveform generation unit, wherein the long axis blood vessel diameter calculation unit sequentially calculates the blood vessel diameter in the long axis from the time difference between the peak waveforms indicated by the A mode waveform generated from the A mode waveform generation unit. . In this way, since the minimum measurement unit is not one pixel as compared with the case where the blood vessel diameter is measured from the long-axis image, the measurement accuracy of the blood vessel diameter on the long axis is improved.

  Preferably, the long-axis blood vessel diameter calculating unit is configured to detect an end-diastolic heart rate from the end-diastolic timing signal generating unit out of a time difference between peak waveforms indicated by the A-mode waveform generated from the A-mode waveform generating unit. The blood vessel diameter on the long axis is sequentially calculated from the time difference synchronized with the synchronization signal. This has the advantage that it is not necessary to use an electrocardiographic induction signal detection device that detects an ECG signal as the end-diastolic timing signal in order to calculate the blood vessel diameter along the long axis.

  Preferably, the blood vessel diameter displacement amount calculation unit uses optical flow analysis to calculate displacements of a plurality of feature point regions between the short axis images repeatedly generated by the short axis image generation unit. Each is calculated sequentially by detecting an area that matches the pattern of the area. In this way, since optical flow analysis is used, a velocity vector can be obtained with high accuracy, and the accuracy of displacement between the obtained feature points can be improved.

It is a figure explaining the whole structure of the biological blood vessel diameter continuous measuring apparatus which is one Example of this invention. It is a figure explaining the control function of the ultrasonic probe of the biological blood vessel diameter continuous measurement apparatus of FIG. 1, and a control apparatus. FIG. 2 is a diagram showing a relationship between an ultrasonic probe positioned by a positioning device and a blood vessel in the continuous blood vessel diameter measuring apparatus of the living body of FIG. The ultrasonic probe is generated from the ultrasonic reflected signals detected by the ultrasonic array probe for the first short axis, the ultrasonic array probe for the long axis, and the ultrasonic array probe for the second short axis of the ultrasonic probe. FIG. 3 is a diagram showing an example in which an ultrasonic image is displayed on the image display device of FIG. 2 and there is no deviation in the ultrasonic probe. It is a figure which shows the graph which shows the continuous measurement value of the blood vessel diameter measured by the electronic control apparatus of FIG. 2, and displayed on an image display apparatus. FIG. 5 is an example of an ultrasonic image displayed on the image display device of FIG. 2, similarly to FIG. 4, illustrating a case where the ultrasonic probe is displaced due to body movement. FIG. 7 is a graph showing a continuous measurement value of a blood vessel diameter that is sequentially measured by the electronic control device of FIG. 2 and displayed on an image display device, and shows a blank period corresponding to a shift period in the ultrasonic probe shown in FIG. 6. is there. It is a figure explaining the example which set the feature point and feature point area | region for calculating a blood vessel displacement in the short-axis image. It is a figure which shows the variation | change_quantity of the blood vessel diameter calculated | required from the displacement of the feature point area | region of FIG. 8, Comprising: It is a figure which illustrates the information for complementing the blank area of FIG. FIG. 10 is a diagram showing a change waveform corresponding to the differentiation of the change amount of the blood vessel diameter shown in FIG. It is a flowchart explaining the principal part of the control action of the electronic controller of FIG. It is a functional block diagram explaining the principal part of the control function of the electronic control apparatus of the other Example of this invention, Comprising: It is a figure equivalent to FIG. It is a flowchart explaining the principal part of the control action of the electronic controller of FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a diagram showing an entire living body blood vessel diameter continuous measuring apparatus 10 according to an embodiment of the present invention. FIG. 2 is a diagram for mainly explaining the overall configuration of the blood vessel diameter continuous measurement apparatus 10 of FIG. 1, that is, the control functions of the sensor holder 22, the hybrid probe unit 24 held by the sensor holder 22, and the electronic control unit 38. . This blood vessel diameter continuous measuring apparatus 10 arranges a hybrid probe unit 24 that functions as an ultrasonic sensor on the skin on the upper limb 11 to continuously measure the blood vessel diameter and inner thickness of a blood vessel 12 such as an artery under the skin. The upper limb 11 protruding to the side of the measurement subject (living body) 16 lying on the bed 14 is placed and placed on the measurement table 20, and also functions as a vascular endothelial function testing device. The blood vessel diameter continuous measurement apparatus 10 uses the hybrid probe unit 24 held by the sensor holder 22 to cross-sectional images (short-axis images) of the blood vessels 12 located directly above the skin 26 from the skin 26 of the upper limb 11. Alternatively, a longitudinal section image (long axis image) is measured.

  The hybrid probe unit 24 functions as an ultrasonic sensor for detecting biological information related to the blood vessel 12, that is, a blood vessel parameter. As shown in FIG. The ultrasonic array probe A and the second short-axis ultrasonic array probe B and the long-axis ultrasonic array probe C connecting the central portions in the longitudinal direction are arranged on one plane, that is, a flat probe surface. And an H-type ultrasonic probe 32 and a multi-axis drive device (positioning device) 34 for positioning the ultrasonic probe 32. FIG. 3 is a diagram showing the relationship between the ultrasonic probe 32 and the blood vessel 12. The first short-axis ultrasonic array probe A, the second short-axis ultrasonic array probe B, and the long-axis ultrasonic array probe C are, for example, a large number of piezoelectric ceramics. Ultrasonic transducers (ultrasound oscillators) are each formed in a longitudinal shape by being linearly arranged.

  A blood vessel diameter continuous measuring apparatus 10 shown in FIG. 2 includes an electronic control device 38 configured by a so-called microcomputer, an image display device 40, and probes A, B, and C of an H-type ultrasonic probe 32. Are provided with an ultrasonic reception / transmission circuit 42 for supplying a drive signal and outputting an ultrasonic reflection signal detected by the ultrasonic probe 32, and a drive motor control circuit 44. When a drive signal is supplied from the ultrasonic reception / transmission circuit 42 by the electronic control unit 38, ultrasonic waves are emitted from the probes A, B, and C of the ultrasonic probe 32 of the hybrid probe unit 24. Next, the ultrasonic reflection signals detected by the probes A, B, and C are received and the ultrasonic reflection signals are processed, so that an ultrasonic image under the skin 26 is generated, and the image display device. 40 is displayed as shown in FIG. 4, and the change in the blood vessel diameter continuously measured is displayed as shown in FIG. When evaluating FMD (blood flow-dependent vasodilatation reaction), the diameter of the intima of the blood vessel 12 (inner diameter) is used as the blood vessel diameter.

  As shown in FIG. 4, the image display device 40 includes a first short-axis image display region S1 for displaying an ultrasonic image by the first short-axis ultrasonic array probe A, and a second short-axis ultrasonic array. A second short-axis image display area S2 for displaying an ultrasonic image by the probe B and a long-axis image display area S3 for displaying an ultrasonic image by the long-axis ultrasonic array probe C are provided. . The first short-axis image display area S1, the second short-axis image display area S2, and the long-axis image display area S3 are provided with a common vertical axis indicating the depth from the skin 26. When the ultrasound image of the blood vessel 12 is generated, the ultrasonic probe 32 is supplied with a drive signal from the drive motor control circuit 44 by the electronic control device 38 so as to be in a predetermined position with respect to the blood vessel 12. 34 is positioned by driving. The predetermined position is a position where the first short-axis ultrasonic array probe A and the second short-axis ultrasonic array probe B are orthogonal to the blood vessel 12 as shown in FIG. This is a position where the axial ultrasonic array probe C is parallel to and directly above the blood vessel 12.

  The sensor holder 22 (FIG. 2) makes a light contact so as not to deform the blood vessel 12 located directly below the skin 26 from the skin 26 of the upper arm 36 of the living body 16 at a desired position in the three-dimensional space, that is, a predetermined position. In this state, the hybrid probe unit 24 is held in a desired posture. The ultrasonic probe 32 is generally well-known between the end face of the ultrasonic probe 32 of the hybrid probe unit 24 and the skin 26 in order to clarify an ultrasonic image by suppressing attenuation of ultrasonic waves and reflection and scattering at the boundary surface. A coupling agent such as jelly (ultrasonic jelly) is interposed. This jelly is a gel-like water-absorbing polymer containing water at a high rate, for example, agar, etc., and has a sufficiently higher specific impedance (= sound speed × density) than air to suppress attenuation of ultrasonic transmission / reception signals. Is. Further, instead of the jelly, a water bag in which water is confined in a resin bag, olive oil, glycerin, or the like can be used.

The sensor holder 22 includes, for example, a magnet base 48 that is fixed to a desk, a pedestal, etc. by magnetic attraction, a unit fixture 50 to which the hybrid probe unit 24 is fixed, a magnet base 48 and the unit fixture 50. Connecting members 54 and 56 each having a tip 52 that is fixed at one end and formed in a spherical shape, and the magnet base 48 and the unit fixture 50 are connected and supported through the connecting members 54 and 56 so as to be relatively movable. And a free arm 58 for performing the above operation. The universal arm 58 includes two links 60 and 62 that are pivotably connected to each other, and a distal end portion 52 of which a predetermined resistance is urged to each distal end portion 52 at one end of the links 60 and 62. And the other ends of the links 60 and 62 are connected to each other so that they can rotate relative to each other. And a rotating joint 72 that is made relatively unrotatable by a fastening force obtained by tightening a male threaded fixing knob 70 screwed into a screw hole penetrating through the connecting portion.

When measuring blood vessel parameters, in FIG. 2, the ultrasonic drive control unit 80 is arranged in accordance with a command from the electronic control unit 38, for example, a plurality of arrays arranged in a line constituting the first short-axis ultrasonic array probe A, for example. Among the ultrasonic transducers, the ultrasonic transducer a ₁ at the end and the like are simultaneously driven at a frequency of about 10 MHz while giving a predetermined phase difference to a certain number of ultrasonic transducer groups, for example, every 15 units. By performing beam forming drive, a convergent ultrasonic beam is sequentially emitted toward the blood vessel 12 in the arrangement direction of the ultrasonic transducers, and the ultrasonic beams are scanned while being shifted one by one. The reflected wave for each radiation is received and input to the electronic control unit 38. An acoustic lens (not shown) for converging the ultrasonic beam in a direction orthogonal to the arrangement direction of the ultrasonic transducers is provided on the radiation surface of the first short-axis ultrasonic array probe A. Yes. In the ultrasonic beam made convergent by the beam forming drive and the acoustic lens as described above, a longitudinal convergence cross section is formed in a direction orthogonal to the arrangement direction of the ultrasonic transducers. The longitudinal direction of the convergent section is a direction orthogonal to the arrangement direction of the ultrasonic transducers and the radiation direction of the beam in plan view. The electronic control unit 38 synthesizes an image based on the reflected wave, generates a transverse cross-sectional image (short axis image) or a vertical cross-sectional image (long axis image) of the blood vessel 12 under the skin 26, and displays the image display device. 40.

  The electronic control unit 38 includes an ultrasonic control unit 80 that repeatedly outputs a drive command to the ultrasonic reception / transmission circuit 42 at a constant period, and a detection processing unit that detects an ultrasonic reflection signal from the ultrasonic reception / transmission circuit 42. 82, an A mode signal processing unit 84 for generating an A mode waveform that is an envelope signal connecting the peak values of the detection waveform of the ultrasonic reflection signal from the long axis ultrasonic array probe C, and A mode signal processing A long-axis blood vessel diameter calculating unit 86 that calculates a long-axis blood vessel diameter from a time difference between peak waveforms appearing in the A-mode waveform generated by the unit 84 corresponding to the blood vessel wall position, and a B-mode signal processing unit. A feature including a short axis image generation unit 88 that repeatedly generates a short axis image of the blood vessel 12 based on a sound wave reflection signal, and a plurality of feature points P between the short axis images repeatedly generated by the short axis image generation unit 88 A displacement calculation unit 90 based on an optical flow of a short-axis image blood vessel cross section that sequentially calculates the displacement of the region P using pattern matching that detects a region that matches the pattern of the feature point region R using optical flow analysis; Among the displacements of the feature point region R calculated by the displacement calculation unit 90, a blood vessel diameter displacement amount calculation unit 92 that calculates the amount of radial displacement of the blood vessel 12 from the displacement of the blood vessel radial direction component, and the blood vessel diameter displacement amount calculation unit Based on the diameter displacement amount of the blood vessel 12 calculated by 92 and the long-axis blood vessel diameter calculated by the long-axis blood vessel diameter calculation unit 86, the complementary blood vessel diameter derived from the short-axis image that is the blood vessel diameter complementary information is calculated. The blood vessel diameter supplementing information processing unit 94 and the time-series change of the long axis blood vessel diameter calculated by the long axis blood vessel diameter calculating unit 86 are normally used as the blood vessel diameter measurement value as shown in FIG. When the ultrasonic sensor is moved by body movement, the blood vessel 12 is lost and the follow-up becomes impossible, and when a blank section is formed in which the long-axis blood vessel diameter cannot be changed as shown in FIG. A blood vessel diameter measuring unit 96 that generates (measures) and records a time-series change in blood vessel diameter using the complementary blood vessel diameter generated by the information processing unit 94 as the blood vessel diameter of the blank section, and the blood vessel diameter measuring unit The display control unit 98 for displaying the time-series change of the blood vessel diameter (absolute value) measured by the display 96 as shown in FIG. 5, the first short-axis ultrasonic array probe A, and the first For example, the display control unit 98 displays so that the short-axis ultrasonic array probe B is orthogonal to the blood vessel 12 and the long-axis ultrasonic array probe C is parallel to and directly above the blood vessel 12. Control based on the short axis image and long axis image shown in FIG. That a drive motor control unit 100 includes functional.

  In the optical flow analysis for deriving the displacement between the feature point regions R between the short axis images in the displacement calculating unit 90, the component in the center direction of the blood vessel cross section of each velocity vector indicates the movement of the blood vessel wall due to pulsation, enlargement, reduction or reduction. Yes. Of these, the difference in the vector components facing each other (for example, proximal or distal to the blood vessel wall) is the amount of change in the blood vessel diameter. When this amount of change is added to the blood vessel diameter at a certain point in time, it is measured as a change over time of the blood vessel diameter to which changes due to pulsation, changes due to enlargement, and reduction in reduction are added. The solid line in FIG. 9 indicates the amount of change in blood vessel diameter that pulsates in synchronization with the pulse, and the broken line indicates the amount of change in diameter specified at the end diastole timing. This broken line is used as the change amount of the blood vessel diameter in the blank section.

  The end-diastolic timing generation unit 102 included in the function of the electronic control unit 38 differentiates the amount of change in the blood vessel diameter indicated by the solid line in FIG. The signal M is generated as a diastole heartbeat synchronization signal. FIG. 10 shows a differential waveform of the change amount of the blood vessel diameter shown by the solid line in FIG. Since this end diastole timing signal M appears clearly like the R wave of the ECG signal, it is reliable and can be used easily.

  This end-diastolic timing signal M is a periodical pulsation time difference between the peak waveforms of the A-mode waveform generated by the A-mode signal processing unit 84, which is the basis of the long-axis blood vessel diameter calculation in the long-axis blood vessel diameter calculation unit 86. Of these, it is used as an end diastole timing signal for extracting the time difference of the end diastole, and the major axis blood vessel diameter is calculated from the extracted time difference. The blood vessel diameter displacement amount calculation unit 92 calculates the diameter change amount of the blood vessel 12 from the displacement synchronized with the end diastole timing signal M among the displacements of the feature point region R calculated by the displacement calculation unit 90. In the diameter measuring unit 96, the diameter change amount for each beat is determined in synchronization with the heartbeat synchronization signal, and the blood vessel diameter is determined and stored in time series from the diameter change amount for each beat. For this reason, it is not necessary to use an electrocardiographic signal detection device that detects an ECG signal as the end diastole timing signal.

  In the electronic control unit 38, for example, in order to evaluate the vascular endothelial function from the blood vessel diameter continuous measurement value obtained as described above, ischemic ischemic reactive hyperemia using a compression band (not shown) wound around the arm. Rate of change in blood vessel diameter (%) [= 100 × (dmax−d) / d] representing subsequent FMD (blood flow-dependent vasodilatation reaction) (where d is the blood vessel diameter at rest and dmax is after release of ischemia) The maximum blood vessel diameter).

FIG. 11 is a flowchart for explaining a main part of the control operation of the electronic control unit 38. In step S1 of FIG. 11 (hereinafter, step is omitted), an ultrasonic reflection signal in a section from before the ischemia by the compression band to after a lapse of a certain time after the ischemia is read. Next, in S2 corresponding to the A-mode signal processing unit 84, an A-mode waveform that is an envelope signal that connects the peak values of the detection waveform of the ultrasonic reflection signal from the long-axis ultrasonic array probe C is generated. . In S3 corresponding to the long-axis blood vessel diameter calculation unit 86, the long-axis blood vessel diameter is calculated from the time difference between peak waveforms appearing in the A-mode waveform generated in S2 corresponding to the blood vessel wall position. Next, in S4 corresponding to the short-axis image generation unit 88,
B-mode signal processing is executed, and a short-axis image of the blood vessel is repeatedly generated based on the ultrasonic reflection signal from the short-axis ultrasonic array probe A or B. In S5 corresponding to the displacement calculation unit 90, a pattern for detecting a region in which the displacement of the plurality of feature point regions R between the plurality of short-axis images repeatedly generated in S4 matches the pattern of the feature point region R. Each is calculated sequentially using matching. Next, in S6 corresponding to the blood vessel diameter displacement amount calculation unit 92, the diameter displacement amount of the blood vessel 12 is calculated from the displacement of the blood vessel radial direction component in the displacement of the feature point region R calculated in S5. In S7 corresponding to the blood vessel diameter complement information processing unit 94, the short axis which is the blood vessel diameter complementation information is calculated based on the diameter displacement amount of the blood vessel 12 calculated in S6 and the long axis blood vessel diameter calculated in S3. A complementary blood vessel diameter derived from the image is calculated. In S8 corresponding to the blood vessel diameter measuring unit 96, the time-series change in the long-axis blood vessel diameter calculated in S3 is always used as the blood vessel diameter measurement value. However, as shown in FIG. When a blank section is formed in which a blood vessel is lost due to the movement of the sensor and tracking is impossible, and a time-series change in the long axis blood vessel diameter cannot be obtained as shown in FIG. 7, the complementary blood vessel diameter generated in S7 is formed. Is used as the blood vessel diameter of the blank section to generate (measure) and record a time-series change in the blood vessel diameter.

  As described above, according to the living body blood vessel diameter continuous measurement apparatus 10 of the present embodiment, the feature point regions R around the plurality of feature points P between the short-axis images repeatedly generated based on the ultrasonic reflection signal are recorded. The displacement is sequentially obtained by pattern matching, the diameter change amount of the blood vessel 12 is sequentially calculated from the displacements of the plurality of feature point regions R, and the time-series change of the blood vessel diameter is measured based on the diameter change amount of the blood vessel 12. Therefore, a time-series change in the diameter of the blood vessel of the living body can be obtained from a short-axis image that is not easily affected by the displacement of the ultrasonic sensor due to body movement or the like.

  Further, according to the living body blood vessel diameter continuous measuring apparatus 10 of the present embodiment, a spike shape is obtained by differentiating the amount of change of the feature point P of the blood vessel radial direction component of the solid line in FIG. Since the end-diastolic timing generation unit 102 that generates the end-diastolic timing signal M obtained as the heartbeat synchronization signal is provided, for example, the vascular diameter displacement amount calculation unit 92 is calculated by the displacement calculation unit 90. Of the displacement of the feature point region R, the diameter change amount of the blood vessel 12 is calculated from the displacement of the blood vessel radial direction component synchronized with the heartbeat synchronization signal, and the blood vessel diameter measuring unit 96 generates one beat in synchronization with the end diastole timing signal M A diameter change amount for each beat is determined, and the blood vessel diameter is determined in time series from the diameter change amount for each beat. Therefore, there is an advantage that it is not necessary to use an electrocardiographic signal detection device that detects an ECG signal as the end diastole timing signal.

  Moreover, according to the living body blood vessel diameter continuous measuring apparatus 10 of the present embodiment, the hybrid probe unit 24 (ultrasound sensor) is arranged to be orthogonal to the blood vessel 12 and the first short axis ultrasonic array probe. A long-axis ultrasonic array probe C and a long-axis ultrasonic array probe C arranged in a direction parallel to the transducer A and the second short-axis ultrasonic array probe B and the blood vessel 12. A long-axis blood vessel diameter calculating unit 86 that sequentially calculates the blood vessel diameter along the long axis based on the ultrasonic reflection signal from the child C is included. The short-axis image generation unit 88 uses the ultrasonic reflection signal detected by the first short-axis ultrasonic array probe A or the second short-axis ultrasonic array probe B to detect the short axis of the blood vessel 12. An axis image is repeatedly generated. The blood vessel diameter measurement unit 96 uses the time-series change in the blood vessel diameter calculated by the long-axis blood vessel diameter calculation unit 86 as the blood vessel diameter measurement value, but there is a blank section in which the time-series change in the blood vessel diameter cannot be obtained. In this case, the blood vessel diameter change amount calculation unit 92 uses the diameter change amount of the blood vessel 12 calculated from the displacement of the radial component of the displacement of the feature point region R in the short-axis image, and the blood vessels in the blank section. Generate time-series changes in diameter. For this reason, even when the blood vessel 12 is lost due to the displacement of the long-axis ultrasonic array probe C due to body movement or the like, the diameter variation of the blood vessel 12 continuous in time series can be measured.

  Further, according to the living body blood vessel diameter continuous measuring apparatus 10 of the present embodiment, the peak value of the detection waveform of the ultrasonic reflection signal is connected based on the ultrasonic reflection signal from the long axis ultrasonic array probe C. An A-mode signal processing unit 84 that generates an A-mode waveform that is an envelope signal is included, and the long-axis blood vessel diameter calculation unit 86 includes a time difference between peak waveforms indicated by the A-mode waveform generated from the A-mode signal processing unit 84. The blood vessel diameter on the long axis is sequentially calculated from the above. For this reason, since the minimum measurement unit is not one pixel as compared with the case where the blood vessel diameter is measured from the long-axis image, the measurement accuracy of the blood vessel diameter on the long axis is improved.

  In addition, according to the living body blood vessel diameter continuous measuring apparatus 10 of the present embodiment, the long axis blood vessel diameter calculating unit 86 includes the time difference between the peak waveforms indicated by the A mode waveform generated from the A mode signal processing unit 84. The blood vessel diameter on the long axis is sequentially calculated from the time difference synchronized with the end diastole timing signal M (heartbeat synchronization vibration) from the end diastole timing signal generator 102. For this reason, there is an advantage that it is not necessary to use an electrocardiographic induction signal detection device that detects an ECG signal as the end-diastolic timing signal in order to calculate the blood vessel diameter along the long axis.

  In addition, according to the living body blood vessel diameter continuous measurement apparatus 10 of the present embodiment, the blood vessel diameter displacement amount calculation unit 92 uses the optical flow analysis between the short axis images repeatedly generated by the short axis image generation unit 88. Since displacements of a plurality of feature point regions R are sequentially calculated by detecting regions that match the pattern of the feature point regions, flow estimation and velocity vectors can be obtained with high accuracy. The accuracy of displacement between P is increased.

  Next, another embodiment of the present invention will be described. In the following description, portions that are the same as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 12 is a functional block diagram for explaining the main part of the control function of the electronic control unit 38 ′ according to another embodiment of the present invention. FIG. 13 shows the main part of the control operation of the electronic control unit 38 ′. It is a flowchart to do.

  Compared with the electronic control device 38 described above, the electronic control device 38 ′ of the present embodiment has an A-mode signal processing unit 84, a long-axis blood vessel diameter calculation unit 86 based on the A-mode waveform peak position, and a blood vessel diameter complementary information processing unit. The difference is that 94 is removed and a blood vessel diameter initial value calculation unit 84 ′ is newly added. Below, it demonstrates centering around difference.

  In FIG. 12, the blood vessel diameter displacement amount calculation unit 92 sequentially calculates the relative displacement of the blood vessel diameter, but cannot calculate the absolute value of the blood vessel diameter. Therefore, the blood vessel diameter initial value calculation unit 84 ′ is generated based on the time difference between the A mode waveform peak positions or from the A mode signal, like the long axis blood vessel diameter calculation unit 86 based on the A mode waveform peak position described above. For example, the absolute value of the blood vessel diameter of the blood vessel 12 before compression by the compression band is calculated based on the interval between the blood vessel walls appearing on the long-axis image. The blood vessel diameter change measuring unit 96 is based on the blood vessel diameter (absolute value) obtained by the blood vessel diameter initial value calculating unit 84 ′ and the relative displacement amount of the blood vessel diameter obtained by the blood vessel diameter displacement calculating unit 92. Then, the change with time of the blood vessel diameter is measured and stored, and the blood vessel diameter continuous measurement value as shown in FIG.

  In FIG. 13, in step S11, an ultrasonic reflection signal is read in the same manner as in S1 described above. Next, in S12 corresponding to the blood vessel diameter initial value calculation unit 84 ′, based on the time difference between the A mode waveform peak positions as in the long axis blood vessel diameter calculation unit 86 based on the A mode waveform peak position, or the A mode signal. For example, the initial value (absolute value) of the blood vessel diameter of the blood vessel 12 before compression by the compression band is calculated on the basis of the interval between the blood vessel walls appearing on the long-axis image generated from. Next, in S13 corresponding to the short-axis image generation unit 88, short-axis images are repeatedly generated as in S4 described above. Subsequently, in S14 corresponding to the displacement calculation unit 90, the displacement of the feature point P is calculated as in S5 described above, and in S15 corresponding to the blood vessel diameter displacement amount calculation unit 92, the blood vessel diameter is determined as in S6 described above. The amount of displacement is calculated. Next, in S16 corresponding to the blood vessel diameter measuring unit 96, the blood vessel diameter is calculated based on the initial value (absolute value) of the blood vessel diameter of the blood vessel 12 obtained in S12 and the displacement amount of the blood vessel diameter obtained in S15. Continuous measurements are determined. In S17 corresponding to the display control unit 98, the continuous measurement value of the blood vessel diameter is displayed on the image display device 40 as in S9 described above.

  According to the present embodiment, the displacement between the feature point regions R in the short-axis image is obtained from the short-axis image almost free from the influence of the displacement due to the body motion by the angular flow analysis using pattern matching. Since the vascular system displacement amount of the vascular diameter direction component is obtained from the displacement between the point regions R, and the vascular diameter continuous measurement value of the blood vessel 12 is obtained from the vascular diameter displacement amount and the vascular diameter initial value (absolute value), The same effect as the above-described embodiment can be obtained.

  As mentioned above, although one Example of this invention was described in detail with reference to drawings, this invention is not limited to this Example, It can implement in another aspect.

  For example, in the above-described embodiment, the displacement detection of the feature point region R between repeatedly generated short-axis images is realized by performing optical flow analysis, but it is not always necessary to use optical flow analysis. What is necessary is just to obtain | require the displacement of the feature point area | region R between images by pattern matching.

  In the above-described embodiment, the displacement of the feature point region R between repeatedly generated short-axis images is obtained by using optical flow analysis. However, clustering of intersection groups of constrained straight lines or the method of least squares is used. The displacement of the feature point region R between the short axis images may be obtained by performing flow estimation.

  Further, in the above-described embodiment, calculation processing is performed after the ultrasonic reflection signal from before compression until a predetermined time has elapsed after the compression is released by the compression band, and the continuous measurement value of the blood vessel 12 is calculated. The patch processing may be real-time processing in which arithmetic processing is executed every time an ultrasonic reflection signal is input.

  Further, in the above-described embodiment, the blood vessel 12 whose blood vessel diameter is to be measured is located directly under the skin. However, by inserting the hybrid probe unit 24 into the body cavity, the blood vessel 12 is located in the organ within the body cavity. May be.

  It should be noted that the above description is merely an embodiment, and other examples are not illustrated. However, the present invention is implemented in variously modified and improved modes based on the knowledge of those skilled in the art without departing from the gist of the present invention. Can do.

10: Continuous blood vessel diameter measuring device 11: Upper limb (living body)
12: Blood vessel 24: Hybrid probe unit (ultrasonic sensor)
84: A-mode signal processing unit 86: Long axis blood vessel diameter calculating unit 88: Short axis image generating unit 90: Displacement calculating unit 92: Blood vessel diameter displacement amount calculating unit 96: Blood vessel diameter measuring unit 102: End diastolic timing generating unit A: First short axis ultrasonic array probe B: second short axis ultrasonic array probe C: long axis ultrasonic array probe

Claims (6)

A biological blood vessel diameter continuous measuring device for continuously measuring the blood vessel diameter of a blood vessel in the living body by bringing an ultrasonic sensor into contact with the living body,
A short-axis image generation unit that repeatedly generates a short-axis image of the blood vessel based on an ultrasonic reflection signal detected by the ultrasonic sensor;
Displacement calculation unit for sequentially calculating displacement of a plurality of feature point areas between short axis images repeatedly generated by the short axis image generation unit using pattern matching for detecting an area that matches the pattern of the feature point area When,
A blood vessel diameter displacement amount calculation unit that calculates a diameter displacement amount of the blood vessel from a displacement of a blood vessel radial direction component of the feature point region calculated by the displacement calculation unit;
A blood vessel diameter continuous measuring device, comprising: a blood vessel diameter measuring unit that measures a time-series change in blood vessel diameter based on the blood vessel diameter displacement calculated by the blood vessel diameter displacement calculating unit.   An end-diastolic timing signal generation unit that generates an end-diastolic heartbeat synchronization signal that periodically indicates the end diastole by differentiating the radial displacement amount of the blood vessel that exhibits pulsation by being sequentially obtained. 1. A blood vessel diameter continuous measurement apparatus. The ultrasonic sensor includes a short-axis ultrasonic array probe arranged so as to be orthogonal to the blood vessel, a long-axis ultrasonic array probe arranged in a direction parallel to the blood vessel, and the long-axis ultrasonic probe. A long-axis blood vessel diameter calculating unit that sequentially calculates a blood vessel diameter in the long axis based on an ultrasonic reflection signal from the ultrasonic array probe;
The short-axis image generation unit repeatedly generates a short-axis image of the blood vessel based on an ultrasonic reflection signal detected by the short-axis ultrasonic array probe,
The blood vessel diameter measurement unit uses a time-series change in the blood vessel diameter calculated by the long-axis blood vessel diameter calculation unit as a blood vessel diameter measurement value, but there is a blank section in which the time-series change in the blood vessel diameter cannot be obtained. In this case, or in the case where all are blank sections, the blank diameter displacement amount calculation unit calculates the blank using the radial displacement amount of the blood vessel calculated from the displacement of the blood vessel radial direction component of the feature point region in the short-axis image. The blood vessel diameter continuous measurement apparatus according to claim 1 or 2, wherein a time-series change of the blood vessel diameter in the section is generated. An A-mode waveform generation unit that generates an A-mode waveform that is an envelope signal that connects the peak values of the detection waveform of the ultrasonic reflection signal based on the ultrasonic reflection signal from the long-axis ultrasonic array probe ,
The long axis blood vessel diameter calculating unit sequentially calculates a blood vessel diameter on a long axis from a time difference between peak waveforms indicated by the A mode waveform generated from the A mode waveform generating unit. The blood vessel diameter continuous measurement device according to any one of 1 to 3. The long-axis blood vessel diameter calculating unit is a time difference synchronized with an end-diastolic heartbeat synchronization signal from the end-diastolic timing signal generating unit among time differences between peak waveforms indicated by the A-mode waveform generated from the A-mode waveform generating unit. The blood vessel diameter continuous measuring apparatus according to claim 3 or 4, wherein the blood vessel diameter on the long axis is sequentially calculated from the above. The blood vessel diameter displacement amount calculation unit uses optical flow analysis to match the displacement of a plurality of feature point regions between the short axis images repeatedly generated by the short axis image generation unit with the pattern of the feature point regions. The blood vessel diameter continuous measurement device according to any one of claims 1 to 5, wherein the blood vessel diameter is continuously calculated by detecting each region.

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