JP5867010B2 - Ultrasonic measuring device and control method of ultrasonic measuring device - Google Patents

Description

  The present invention relates to an apparatus for calculating the diameter of a blood vessel to be measured by a subject using ultrasound.

  Conventionally, devices for measuring blood flow, blood vessel diameter and blood pressure using ultrasonic waves, and devices for measuring the elasticity of blood vessels have been devised. These devices are characterized in that measurement can be performed without causing pain or discomfort to the subject.

  For example, Patent Document 1 discloses a technique for calculating blood pressure using a blood vessel diameter or a blood vessel cross-sectional area. Further, in Patent Document 2, a peak of an amplitude value reflecting the internal structure of a blood vessel wall is detected for a reflected wave of an ultrasonic beam that passes through a living body, and a blood vessel displacement, a blood vessel diameter is detected using the detection result. A technique for measuring the thickness of a blood vessel wall is disclosed.

JP 2004-41382 A JP 2000-271117 A

  When measuring the blood vessel diameter of the measurement target blood vessel, it is ideal to perform the measurement by irradiating the ultrasonic beam perpendicularly to the long axis of the measurement target blood vessel and detecting the reflected wave. However, for example, when the subject is under free action, the relative positional relationship and orientation between the ultrasonic beam and the blood vessel to be measured may change due to the motion of the subject. That is, it is not guaranteed that the ultrasonic beam is always irradiated perpendicularly to the long axis of the measurement target blood vessel, and there is a possibility that the ultrasonic beam is irradiated obliquely with respect to the long axis of the measurement target blood vessel. In this case, if the blood vessel diameter is measured based on the reflected wave of the ultrasonic wave, there is a possibility that the measurement is made larger than the true blood vessel diameter.

  The present invention has been made in view of the above-described problems, and an object thereof is to propose a new method for correctly measuring the blood vessel diameter of a blood vessel to be measured.

  A first form for solving the above-described problem is that an ultrasonic transmission / reception unit having a plurality of ultrasonic transducers and a measurement result from a lumen-intima boundary of a blood vessel to be measured based on the reception result of the ultrasonic wave. Based on a detection unit that detects a reflected wave, a control unit that controls the transmission / reception unit so that the detection unit can detect a reflected wave from the lumen-intima boundary, and a reception result of the ultrasonic wave A blood vessel diameter calculating unit that calculates a blood vessel diameter of the measurement target blood vessel.

  According to another aspect, there is provided a method for controlling an ultrasonic measurement device including an ultrasonic wave transmission / reception unit having a plurality of ultrasonic transducers, wherein the lumen of a blood vessel to be measured is based on a reception result of the ultrasonic wave Based on detecting the reflected wave from the intima boundary, controlling the transmission / reception unit to enable detection of the reflected wave from the lumen intima boundary, and the reception result of the ultrasonic wave, A control method including calculating a blood vessel diameter of the measurement target blood vessel may be configured.

  According to the first embodiment and the like, the reflected wave from the lumen-intima boundary of the blood vessel to be measured is detected based on the reception result of the ultrasonic wave by the ultrasonic wave transmitting / receiving unit having a plurality of ultrasonic transducers. If the relative positional relationship and orientation between the transmitter / receiver and the measurement target blood vessel are appropriate, it is possible to detect the reflected wave from the lumen-intima boundary, and based on the detection result, the blood vessel diameter of the measurement target blood vessel is determined. Can be calculated.

  However, if the relative positional relationship and direction between the transmission / reception unit and the blood vessel to be measured are inappropriate, the reflected wave from the lumen-intima boundary may not be detected. Therefore, the transmission / reception unit is controlled so that the reflected wave from the lumen intima boundary can be detected. As a result, the relative positional relationship and orientation between the transmitting / receiving unit and the measurement target blood vessel can be maintained in an appropriate state, and the blood vessel diameter of the measurement target blood vessel can be correctly measured.

  Further, as a second mode, in the ultrasonic measurement apparatus according to the first mode, the detection unit detects a reflected wave from a lumen intima boundary on each of the front wall side and the rear wall side as viewed from the transmission / reception unit. The control unit is capable of depending on a combination of the presence / absence of detection of a reflected wave from the lumen-intima boundary on the front wall side and the presence / absence of detection of a reflected wave from the lumen-intima boundary on the rear wall side. Then, an ultrasonic measurement device that changes the control content of the transmission / reception unit may be configured.

  Even if the reflected wave from the lumen intima boundary on the front wall side as seen from the transmitting / receiving unit can be detected, the reflected wave from the lumen intima boundary on the rear wall side from the transmitting / receiving unit may not be detected. The reverse is also possible. Therefore, as in the second embodiment, according to the combination of the presence / absence of detection of the reflected wave from the lumen-intima boundary on the front wall side and the presence / absence of detection of the reflected wave from the lumen-intima boundary on the rear wall side The control content of the transmission / reception unit is changed. Thereby, it becomes possible to control a transmission / reception part appropriately.

  Further, as a third mode, in the ultrasonic measurement apparatus according to the first or second mode, the control unit controls any of a transmission position, a focus, and a transmission direction of the ultrasonic beam by the transmission / reception unit. It is good also as comprising an ultrasonic measuring device.

  According to the third embodiment, it is possible to detect a reflected wave from the lumen-intima boundary by controlling any one of the transmission position, focus, and transmission direction of the ultrasonic beam by the transmission / reception unit. It is possible to control the transmission / reception unit.

  Further, as a fourth mode, in the ultrasonic measurement device according to any one of the first to third modes, a wall thickness measurement unit that measures the wall thickness of the blood vessel to be measured based on the reception result of the ultrasonic wave is further provided And the control unit is configured to detect ultrasonic waves from the transmission / reception unit when the detection by the detection unit is impossible and when the wall thickness measured by the wall thickness measurement unit is changed before and after the detection becomes impossible. It is good also as comprising an ultrasonic measuring device which has a wall thickness change time control part which controls the transmission direction of a beam.

  One of the factors that makes it impossible to detect a reflected wave from the lumen intima boundary is a change in the irradiation angle of the ultrasonic beam with respect to the blood vessel to be measured. When the irradiation angle of the ultrasonic beam changes, the measurement result of the wall thickness of the blood vessel to be measured also changes. Therefore, as in the fourth embodiment, the wall thickness of the blood vessel to be measured is measured based on the reception result of the ultrasonic waves. When the reflected wave from the lumen-intima boundary cannot be detected, and the wall thickness measured before and after it becomes impossible, the transmission direction of the ultrasonic beam by the transmitter / receiver is controlled. To do.

  Further, as a fifth mode, in the ultrasonic measurement device according to the fourth mode, when the wall thickness change, the control unit of the ultrasonic beam for canceling the increase when the wall thickness increases It is good also as comprising the ultrasonic measurement apparatus which calculates and controls the transmission direction of the said ultrasonic beam.

  When the ultrasonic beam is irradiated obliquely onto the measurement target blood vessel, the wall thickness of the measurement target blood vessel is measured to be larger than the actual thickness. Therefore, as in the fifth embodiment, when the wall thickness of the blood vessel to be measured increases, the transmission direction of the ultrasonic beam for canceling the increase is calculated to control the transmission direction of the ultrasonic beam. Thereby, it is possible to control to irradiate the measurement target blood vessel with an ultrasonic beam at an appropriate angle.

  Further, as a sixth form, in the ultrasonic measurement apparatus of the fourth or fifth form, the control unit detects a reflected wave from a lumen-intima boundary on the front wall side when viewed from the transmission / reception unit, In addition, when the reflected wave from the lumen-intima boundary on the rear wall side is not detected, an ultrasonic measurement device that causes the wall thickness change control unit to function may be configured.

  In particular, when a reflected wave from the lumen-intima boundary on the rear wall side as viewed from the transmission / reception unit is not detected, there is a possibility that the ultrasonic wave is irradiated obliquely to the measurement target blood vessel. Therefore, as in the sixth embodiment, a reflected wave from the lumen-intima boundary on the front wall side as viewed from the transmitter / receiver is detected, and a reflected wave from the lumen-intima boundary on the rear wall side is detected. If not, make the wall thickness change control function.

  Further, as a seventh aspect, in the ultrasonic measurement apparatus according to any one of the first to sixth aspects, the control unit is configured to transmit an ultrasonic beam from the transmission / reception unit when detection by the detection unit is impossible. An ultrasonic measurement device that preferentially controls the transmission direction may be configured.

  According to the seventh aspect, when the reflected wave from the lumen-intima boundary cannot be detected, the transmission direction of the ultrasonic beam by the transmission / reception unit is preferentially controlled. Accordingly, it is possible to perform other control of the ultrasonic beam (for example, control of the transmission position and focus) while optimizing the transmission direction of the ultrasonic beam.

(1) Schematic configuration diagram of an ultrasonic measurement device. (2) Configuration diagram of each ultrasonic transducer array. The figure which shows the positional relationship of a probe and a measurement object blood vessel. The figure which shows the result of having converted the intensity | strength of the reflected wave of an ultrasonic wave into the brightness | luminance. Explanatory drawing of a detection pattern. Explanatory drawing of the factor according to a detection pattern, and the processing content. Explanatory drawing of the correction method of a relative angle. Explanatory drawing of the correction method of a relative angle. The figure which shows an example of the correlation with a relative angle and wall thickness increase rate. Explanatory drawing of the change method of an irradiation position. The block diagram which shows an example of a function structure of an ultrasonic measuring device. The flowchart which shows the flow of a main process. The flowchart which shows the flow of a process at the time of abnormality. The block diagram of the modification of a probe.

  As an embodiment to which the present invention is applied, an ultrasonic measurement apparatus that measures the diameter of the carotid artery using the subject's neck as the measurement target site and the carotid artery as the measurement target blood vessel will be described. However, it is needless to say that embodiments to which the present invention is applicable are not limited to the embodiments described below.

1. Device Configuration FIG. 1A is a schematic configuration diagram of an ultrasonic measurement device 1 in the present embodiment. The ultrasonic measurement device 1 includes a probe 10 and a main body device 20. The probe 10 is provided with a stretchable annular band 15, and the subject uses the band 15 to attach the probe 10 to the neck that is the measurement target site.

  The probe 10 includes a probe 110. The probe 110 includes a plurality of ultrasonic transducer arrays 11-1 to 11-N arranged in parallel. As shown in FIG. 1B, each ultrasonic transducer array 11-1 to 11-N includes a plurality of ultrasonic transducers (11-1a, 11-1b,. ) Arranged in a row. Therefore, it can be said that the probe 10 includes ultrasonic transducers in a matrix in the vertical and horizontal directions.

  The proper posture when the probe 10 is attached to the neck (hereinafter referred to as “appropriate attachment posture”) is that the normal direction of the measurement surface 10X of the probe 10 and the major axis direction of the blood vessel to be measured are orthogonal to each other. In addition, the orientation of the ultrasonic transducer arrays 11-1 to 11-N is a posture along the long axis direction of the blood vessel to be measured.

  The probe 10 can switch an ultrasonic transducer array (or an ultrasonic transducer) that transmits an ultrasonic beam, change a transmission direction of the ultrasonic beam to be transmitted, or change a so-called focus position. It is configured. Since these control items are publicly known, detailed description is omitted.

  The main unit 20 is the main unit of the ultrasonic measurement apparatus 1 and is connected to the probe 10 via a cable. A neck strap 23 is attached to a predetermined position of the main unit 20 so that the subject can use the main unit 20 while hanging from the neck.

  An operation button 24, a liquid crystal display 25, and a speaker 26 are provided on the front surface of the main body device 20. Although not shown, a control board for integrated control of the ultrasonic measurement device 1 is built in the main body device 20. On the control board, a microprocessor, a memory, a circuit for transmitting and receiving ultrasonic waves, an internal battery, and the like are mounted.

2. Principle FIG. 2 is a cross-sectional view of the neck schematically showing the positional relationship between the probe 10 and the blood vessel to be measured. The probe 10 is mounted in an appropriate mounting posture. The length of each of the ultrasonic transducer arrays 11-1 to 11-N (the arrangement length of the ultrasonic transducers constituting the array) is configured to be larger than the diameter of the blood vessel to be measured. On the other hand, the blood vessel has a lumen, an intima, a media, and an outer membrane, but the illustration of the media is omitted for simplicity.

  Among the ultrasonic transducer arrays 11-1 to 11-N constituting the probe 10, one ultrasonic transducer array to be driven is selected, and the ultrasonic transducers constituting the one ultrasonic transducer array are superseded. A sound beam is transmitted. In FIG. 2, the first ultrasonic transducer array 11-1 is a driving target. The ultrasonic beam has a property of reflecting at a portion where there is a difference in acoustic impedance. The ultrasonic beam that has passed through the outer membrane travels from the inner membrane to the inner membrane and is reflected at the boundary between the inner membrane and the lumen (hereinafter referred to as the “luminal intima boundary”). In FIG. 2, for the sake of simplicity, only one of the ultrasonic beams transmitted from each ultrasonic transducer is reflected.

  At the lumen-intima boundary, there are lumen-intima boundaries on the front wall side and the rear wall side as seen from the probe 10. In the present embodiment, the lumen intima boundary on the front wall side is referred to as “front wall lumen intima boundary”, and the lumen intima boundary on the rear wall side is referred to as “rear wall lumen intima boundary”. Called. The ultrasonic beam is reflected at the front wall lumen intima boundary and the rear wall lumen intima boundary, respectively, and the reflected wave is received (detected) by the ultrasonic transducer. For example, when observed with a so-called B-mode image, the front wall lumen intima boundary and the rear wall lumen intima boundary are each observed as a semicircular arc.

  FIG. 3 is a diagram illustrating a result of converting the intensity of the reflected wave detected in the proper mounting posture with respect to the distance (horizontal axis) from the probe 10 into luminance. From the graph of FIG. 3, it can be seen that the peak group “P0” appears in a distance region shorter than the distance “d1”. These peak groups “P0” are peak groups corresponding to the outer membrane to the inner membrane on the front wall side of the blood vessel to be measured. At the distance “d1”, a peak “P1” lower than the peak group “P0” appears. This peak “P1” corresponds to the front wall lumen intima boundary.

  Ultrasonic reflection hardly occurs in the lumen of the measurement target blood vessel. For this reason, a relatively small luminance value is maintained between the distance “d1” and the distance “d2”. The luminance increases at the distance “d2”, and the medium height peak “P2” appears again. This peak “P2” is a peak corresponding to the intima boundary of the rear wall lumen.

  As described above, when the intensity of the reflected wave of the ultrasonic wave is expressed by brightness, a medium height peak is observed at the front wall lumen intima boundary and the rear wall lumen intima boundary. By detecting these peaks, it is possible to detect reflected waves from the front wall lumen intima boundary and the rear wall lumen intima boundary.

  This peak detection can be realized, for example, by performing a peak search within a predetermined luminance threshold range. As can be seen from FIG. 3, a high luminance value is maintained at the position of the outer membrane to the inner membrane, but the luminance value decreases to a medium level at the lumen-intima boundary. The thickness of the outer membrane to the inner membrane is about 0.3 [mm], and the change in luminance corresponding to this thickness is roughly determined. Therefore, it is possible to assume a luminance range in which peaks of the front wall lumen intima boundary and the rear wall lumen intima boundary are observed, and the peak search may be performed using this range as a threshold range.

  In addition to the above method, a peak detection method can be selected as appropriate. For example, since the composition is different between the blood vessel wall and the external tissue, a strong reflected signal (ultrasonic echo) is obtained at the boundary. Utilizing this phenomenon, for example, by applying the technique disclosed in Japanese Patent Application Laid-Open No. 11-318896 and Japanese Patent Application Laid-Open No. 2009-39277, the front wall lumen intima boundary and the rear wall lumen intima Boundary peaks can be detected.

  FIG. 4 is an explanatory diagram of detection patterns of the front wall lumen intima boundary and the rear wall lumen intima boundary. The combination of detection / non-detection of the rear wall lumen intima boundary in the vertical column and detection / non-detection of the front wall lumen intima boundary in the horizontal column is shown.

  The probe 10 is attached to the neck of the subject. However, since the subject is under free action, a deviation may occur in the attachment position of the probe 10 due to the body movement of the subject. As a result, the relative positional relationship and orientation of the probe 10 with respect to the blood vessel to be measured changes, and a posture that is not an appropriate mounting posture (hereinafter, referred to as “inappropriate mounting posture”) can be obtained. In an improper wearing posture, it may be impossible to detect a reflected wave from the lumen-intima boundary of the blood vessel to be measured.

  If the reflected waves from the front wall lumen intima boundary and the back wall lumen intima boundary are both detected, the relative positional relationship and orientation between the probe 10 and the blood vessel to be measured are appropriate. (Hereinafter referred to as “measurement permissible state”) (OK). However, if one or both of the reflected waves from the front wall lumen intima boundary and the rear wall lumen intima cannot be detected (hereinafter referred to as “measurement non-permitted state”). It can be said that the relative positional relationship and orientation between the probe 10 and the blood vessel to be measured are inappropriate (NG).

  Note that the proper mounting posture and the improper mounting posture, and the measurement allowable state and the measurement non-permissible state are not necessarily in a correspondence relationship. This is because it is one of the features of the present embodiment that the measurement is permitted even in an improper mounting posture.

  In the present embodiment, a detection pattern in which a reflected wave from the front wall lumen intima boundary can be detected and a reflected wave from the rear wall lumen intima boundary is not detected is defined as “pattern A”. A pattern in which a reflected wave from the rear wall lumen intima boundary can be detected and a reflected wave from the front wall lumen intima boundary is not detected is defined as “pattern B”. A detection pattern in which both reflected waves from the front wall lumen intima boundary and the back wall lumen intima boundary are not detected is defined as “pattern C”.

  FIG. 5 is a diagram showing the factor that becomes the detection pattern and the processing content for the detection pattern for each detection pattern. Hiragana characters written in parentheses in the factor column correspond to katakana characters written in parentheses in the processing content column.

  Factors of pattern A are (i) change in relative angle between the ultrasonic beam and the blood vessel to be measured, (b) the position where the rear wall lacks flatness is the irradiated position, (ha) probe and measurement object Changes in the distance between blood vessels are defined. In addition, (a) relative angle correction, (b) irradiation position change, and (c) recognizable range adjustment are defined as processing contents for these factors.

  As a factor of the pattern B, (ii) a change in the distance between the probe and the measurement target blood vessel, in which the position where the flatness of the front wall is absent becomes the irradiated position, is defined. As processing contents for these factors, (2) irradiation position change and (c) recognizable range adjustment are defined.

  As a factor of the pattern C, (e) a large change in the relative angle between the ultrasonic beam and the blood vessel to be measured is determined. Further, (e) ultrasonic beam angle adjustment is defined as the processing content for this factor.

  In the present embodiment, the pattern of whether or not the reflected wave can be detected from the lumen-intima boundary on the front wall side and the rear wall side as viewed from the probe 10 (transmission / reception unit) is determined. And the process according to the process content defined in association with the determined detection pattern is performed. This is based on the combination of the presence / absence of detection of the reflected wave from the lumen-intima boundary on the front wall side and the presence / absence of detection of the reflected wave from the lumen-intima boundary on the rear wall side. It corresponds to changing. Hereinafter, each detection pattern will be described in detail.

(1) When the detection pattern is the pattern A As a first factor that the detection pattern becomes the pattern A, (ii) a change in the relative angle between the ultrasonic beam and the blood vessel to be measured can be considered.

  6 and 7 are diagrams schematically showing the positional relationship between the probe 10 and the blood vessel to be measured, and the ultrasonic beam transmitted from the ultrasonic transducer of the fourth ultrasonic transducer array 11-4. It is the figure which looked at a mode that a measurement object blood vessel is irradiated from the side. FIG. 6 shows the case of the proper mounting posture, and the ultrasonic beam transmitted from the ultrasonic transducer is irradiated perpendicularly to the long axis direction of the blood vessel to be measured. Here, on the basis of the case where the ultrasonic beam is irradiated perpendicularly to the major axis direction of the blood vessel to be measured, the deflection angle of the ultrasonic beam from there is defined as “relative angle”. In the state of FIG. 6, “relative angle θ = 0 degree”.

  On the other hand, in FIG. 7, as a result of the slightly inclined inclination of the probe 10, the ultrasonic beam transmitted from the ultrasonic transducer is irradiated obliquely by a predetermined angle with respect to the major axis direction of the blood vessel to be measured. ing. In the state of FIG. 7, “relative angle θ ≠ 0 degrees”.

  The ultrasonic beam is reflected and transmitted repeatedly and reaches the rear wall lumen intima, so that it is attenuated more than when emitted. In addition, the rear wall lumen intima boundary is farther away from the ultrasound transmission source than the front wall lumen intima boundary. Therefore, when the relative angle θ is not “0 degree” as shown in FIG. 7, it is more difficult for the rear wall to receive the refracted reflected wave than the front wall, and the detection may not be performed. Therefore, in the present embodiment, when the reflected wave from the front wall lumen intima boundary is detected and the reflected wave from the rear wall lumen intima boundary is not detected, Correct the relative angle.

  FIG. 8 is a graph showing the correlation between the relative angle and the wall thickness increase rate. The wall thickness increase rate refers to the ratio of the wall thickness to the reference wall thickness based on the wall thickness in the case of “θ = 0 degrees”. As shown in FIG. 8, the wall thickness increase rate tends to increase exponentially as the relative angle increases.

  In this embodiment, the reference wall thickness is measured based on the reception result of the reflected wave as an initial setting. During the subsequent measurement, processing for measuring the wall thickness of the blood vessel to be measured is performed as needed based on the reception result of the reflected wave. And when it corresponds to the pattern A as a detection pattern, and when the measured value of the wall thickness of the blood vessel to be measured has changed, the wall thickness increase rate is calculated. Then, by determining the relative angle θ corresponding to the calculated wall thickness increase rate based on the correlation between the relative angle and the wall thickness increase rate shown in FIG. The correction amount of the angle necessary for vertical irradiation is obtained. Then, the relative angle is corrected using the obtained correction amount.

  In the present embodiment, the relative angle is corrected by controlling the transmission direction of the ultrasonic beam. That is, when the wall thickness increases, the transmission direction of the ultrasonic beam for canceling the increase is calculated to control the transmission direction of the ultrasonic beam.

  The second factor that causes the detection pattern to be pattern A is that (ro) the lack of flatness of the rear wall of the blood vessel becomes the irradiated position. The outer and inner surfaces of the blood vessel are not necessarily smooth and flat. The case where the position lacking flatness is the position irradiated with the ultrasonic beam corresponds to this (b).

  More specifically, when the mounting posture of the probe 10 changes, the position where the flatness of the rear wall of the blood vessel to be measured becomes the irradiation position of the ultrasonic beam corresponds to this (b). . As a result of irradiating the non-flat portion of the rear wall of the blood vessel to be measured with the ultrasonic beam, the reflected wave from the intima boundary of the rear wall cannot be detected. In this case, as the processing content (b), the irradiation position of the ultrasonic beam is changed by controlling the transmission position of the ultrasonic beam.

  FIG. 9 is a diagram for explaining control of the transmission position of the ultrasonic beam. The transmission position of the ultrasonic beam is controlled by changing the array to be driven and controlled among the ultrasonic transducer arrays 11-1 to 11-N. For example, the control for sequentially switching the array to be driven is performed until the rear wall lumen intima boundary can be detected.

  A third factor that causes the detection pattern to be pattern A is (ha) a change in the distance between the probe 10 and the blood vessel to be measured. For example, the focus is changed by the contact pressure of the probe 10 with respect to the measurement target region (neck) due to the contraction of the muscle fibers of the neck (measurement target region) due to the subject's movement or the belt-like portion 15 having elasticity. This is a case where the position changes and the distance range in which the reflected wave of the ultrasonic wave can be recognized changes. In this case, the recognizable range is adjusted as the processing content (c). In this embodiment, the recognizable range is adjusted by controlling the focus of the ultrasonic beam.

  Specific focus control can be realized by, for example, an electronic focus method. More specifically, the focus position is shifted by adjusting the timing for driving the ultrasonic transducer, thereby adjusting the recognizable range. In the present embodiment, the recognizable range is adjusted based on the distance from the ultrasonic transducer to the outer membrane position of the anterior wall of the blood vessel to be measured (hereinafter referred to as “outer membrane position distance”).

  For example, as an initial setting, the epicardial position distance is calculated based on the reception result of the ultrasonic wave with the probe 10 mounted in the proper mounting posture, and the value is stored in the storage unit as the reference epicardial position distance. . After the measurement is started, the outer membrane position distance is calculated as needed based on the reception result of the ultrasonic wave, and is compared with the reference outer membrane position distance stored in the storage unit.

  If the outer membrane position distance is shorter than the reference outer membrane position distance, it is assumed that the distance between the probe 10 and the blood vessel to be measured is shorter. Therefore, in this case, the drive control of the ultrasonic transducer is adjusted so as to shift the focus position to the back side.

  On the other hand, if the outer membrane position distance is longer than the reference outer membrane position distance, it is assumed that the distance between the probe 10 and the blood vessel to be measured is longer. Therefore, in this case, the drive control of the ultrasonic transducer is adjusted so as to shift the focus position to the near side.

(2) When the detection pattern becomes the pattern B As a first factor that the detection pattern becomes the pattern B, (i) the lack of flatness of the front wall becomes the irradiated position. This is a case where the reflected wave from the intima boundary of the front wall cannot be detected as a result of irradiating the non-flat portion of the front wall of the blood vessel to be measured. In this case, similarly to the pattern A, the irradiation position of the ultrasonic beam is changed by controlling the transmission position of the ultrasonic beam. Specifically, the irradiation position of the ultrasonic beam on the anterior wall of the blood vessel is changed by sequentially switching the array to be driven.

  The second factor that causes the detection pattern to be the pattern B is (ha) a change in the distance between the probe 10 and the blood vessel to be measured. This is a case where the recognizable range changes as the distance between the probe 10 and the measurement target blood vessel with respect to the measurement target region of the subject changes. Also in this case, similarly to the pattern A, the recognizable range is adjusted by changing the focus position by the electronic focus method, for example.

  Note that, as a factor that causes the detection pattern to be the pattern B, as in the case of the pattern A, a change in the relative angle between the ultrasonic beam and the blood vessel to be measured can also be considered. However, even if the ultrasonic beam is irradiated to the blood vessel to be measured somewhat obliquely, the front wall has a physical distance closer to the ultrasonic beam emission source than the rear wall. A situation in which a reflected wave from the boundary cannot be detected hardly occurs. Therefore, in the present embodiment, when the detection pattern is the pattern B, the relative angle is not corrected.

(3) When the detection pattern is the pattern C As a factor that the detection pattern becomes the pattern C, (e) a large change in the relative angle between the ultrasonic beam and the blood vessel to be measured can be cited. This is a case where the reflected wave from the front wall lumen intima boundary and the back wall lumen intima boundary is not detected because the relative angle between the ultrasonic beam and the blood vessel to be measured changes greatly.

  In this case, the beam angle of the ultrasonic beam is changed (swinged) with respect to the major axis direction of the blood vessel to be measured, and the reflected wave from the front wall lumen intima boundary and the reflected wave from the rear wall lumen intima boundary Control for searching for a direction in which at least one of them can be detected is performed. The beam angle of the ultrasonic beam can be changed by shifting the timing at which the ultrasonic wave is transmitted from each ultrasonic transducer (so-called phase shift).

  If a reflected wave from any lumen intima boundary is detected, either detection pattern A or pattern B is obtained. Therefore, after that, the process may be performed according to the processing content associated with the detection pattern. This processing procedure is equivalent to preferentially controlling the transmission direction of the ultrasonic beam by the transmission / reception unit when detection of the reflected wave from the lumen-intima boundary is impossible.

3. Functional Configuration FIG. 10 is a block diagram illustrating an example of a functional configuration of the ultrasonic measurement apparatus 1. The ultrasonic measurement device 1 includes a probe 10 and a main body device 20.

  The probe 10 is a small contact mounted on a measurement target site of a subject, and includes a probe 110 and a transmission / reception circuit unit 120. The probe 10 corresponds to an ultrasonic transmission / reception unit having a plurality of ultrasonic transducers.

  The probe 110 includes a plurality of ultrasonic transducer arrays 11-1 to 11 -N, and switches ultrasonic transducer arrays according to drive signals from the transmission / reception circuit unit 120 to transmit / receive ultrasonic waves. Do.

  The transmission / reception circuit unit 120 is a transmission / reception circuit that switches between the transmission mode and the reception mode in a time division manner in accordance with a trigger signal output from the transmission / reception control unit 320. The transmission / reception circuit unit 120 includes an ultrasonic oscillation circuit that generates a pulse signal of a predetermined frequency, a transmission delay circuit that delays the generated pulse signal, and the like as a configuration for transmission. The reception configuration includes a reception delay circuit that delays the reception signal, a filter that extracts a predetermined frequency component from the reception signal, an amplifier that amplifies the reception signal, and the like.

  While receiving the trigger signal from the transmission / reception control unit 320, the transmission / reception circuit unit 120 generates a pulse signal at a timing synchronized with the trigger signal, and delays the pulse signal according to a predetermined delay time setting value. Output to the probe 110. Thereby, the transmission wave is delayed as needed with respect to the ultrasonic transducers arranged in an array, and a phase shift for changing the angle of the ultrasonic beam is realized. On the other hand, while the trigger signal is not received from the transmission / reception control unit 320, the ultrasonic reception signal output from the probe 110 is received, and the reception signal is delayed in accordance with a predetermined delay time setting value. Are attenuated and then output to the detector 220.

  In addition, although the transmission / reception circuit unit 120 is illustrated as a configuration provided in the probe 10, the configuration provided in the main body device 20 may be used.

  The main device 20 includes, for example, a detection unit 220, a signal processing unit 240, a processing unit 300, an operation unit 400, a display unit 500, a sound output unit 600, a communication unit 700, a clock unit 800, and a storage. Unit 900.

  The detection unit 220 detects the reception signal (RF signal) of the ultrasonic echo output from the transmission / reception circuit unit 120. The detection unit 220 includes a logarithmic detection circuit that performs logarithmic compression and amplitude envelope detection on the reflected wave of the ultrasonic wave.

  The signal processing unit 240 performs signal processing necessary for the processing unit 300 to calculate a blood vessel diameter, detect a lumen-intima boundary, and the like on the signal detected by the detection unit 220. The signal processing unit 240 includes, for example, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), and the like. For example, the signal processing unit 240 performs processing for calculating the phase and amplitude of the reception signal of the ultrasonic echo, and also executes processing for converting the strength of the reception signal of the ultrasonic echo into luminance.

  The processing unit 300 is a control device and an arithmetic device that comprehensively control each unit of the ultrasonic measurement apparatus 1 and includes, for example, a processor such as a CPU (Central Processing Unit). The processing unit 300 includes a lumen intima boundary detection unit 310, a transmission / reception control unit 320, a wall thickness measurement unit 330, and a blood vessel diameter calculation unit 340 as main functional units. However, these functional units are only described as one embodiment, and all the functional units are not necessarily required as essential components.

  The lumen-intima boundary detection unit 310 detects a reflected wave from the lumen-intima boundary (front wall lumen-intima boundary and rear wall lumen-intima boundary) based on the processing result of the signal processing unit 240. .

  The transmission / reception control unit 320 controls transmission / reception of ultrasonic waves by the probe 10. In particular, in the present embodiment, the transmission / reception control unit 320 controls the transmission / reception circuit unit 120 so that a reflected wave from the lumen-intima boundary can be detected by the lumen-intima boundary detection unit 310. More specifically, the control content of the probe 10 is changed according to the combination of the presence / absence of detection of a reflected wave from the front wall lumen intima boundary and the presence / absence of detection of a reflected wave from the rear wall lumen intima boundary. To do. The transmission / reception control unit 320 includes a wall thickness change control unit 321 as a functional unit.

  The wall thickness change control unit 321 cannot detect the lumen-intima boundary detection unit 310, and the wall thickness of the measurement target blood vessel measured by the wall thickness measurement unit 330 before and after the change becomes impossible. If there is, the transmission direction of the ultrasonic beam by the probe 10 is controlled.

  The wall thickness measurement unit 330 measures the wall thickness of the blood vessel to be measured based on the reception result of the ultrasonic waves. The blood vessel diameter calculation unit 340 calculates the blood vessel diameter of the measurement target blood vessel based on the reception result of the ultrasonic waves.

  The operation unit 400 is an input device that includes a button switch and the like, and outputs a signal of a pressed button to the processing unit 300. By operating the operation unit 400, various instructions such as a blood vessel diameter measurement start instruction are input. The operation unit 400 corresponds to the operation button 24 in FIG.

  The display unit 500 is a display device that includes an LCD (Liquid Crystal Display) or the like and performs various displays based on display signals input from the processing unit 300. The display unit 500 displays the blood vessel diameter and the like calculated by the blood vessel diameter calculation unit 340. The display unit 500 corresponds to the liquid crystal display 25 of FIG.

  The sound output unit 600 includes a speaker or the like, and is a sound output device that outputs various sounds based on a sound output signal input from the processing unit 300. The sound output unit 600 corresponds to the speaker 26 of FIG.

  The communication unit 700 is a communication device for transmitting / receiving information used inside the device to / from an external information processing device such as a personal computer (PC) under the control of the processing unit 300. As a communication method of the communication unit 700, a form of wired connection via a cable compliant with a predetermined communication standard, a form of connection via an intermediate device also used as a charger called a cradle, or short-range wireless communication is used. Various systems such as a wireless connection type can be applied.

  The clock unit 800 is configured to include a crystal oscillator including a crystal resonator and an oscillation circuit, and is a time measuring device that measures time. The time measured by the clock unit 800 is output to the processing unit 300 as needed.

  The storage unit 900 includes a storage device such as a ROM (Read Only Memory), a flash ROM, or a RAM (Random Access Memory). The storage unit 900 stores various programs, data, and the like for realizing various functions such as a system program of the ultrasonic measurement apparatus 1, a transmission / reception control function, and a blood vessel diameter calculation function. In addition, it has a work area for temporarily storing data being processed and results of various processes.

  The storage unit 900 stores, as a program, for example, a main program 910 that is read by the processing unit 300 and executed as a main process (see FIG. 11). The main program 910 includes an abnormal time processing program 911 executed as an abnormal time processing (see FIG. 12) as a subroutine. These processes will be described later in detail using a flowchart.

  Further, the storage unit 900 stores pattern definition data 920, relative angle determination data 930, initial calibration data 940, wall thickness data 950, and blood vessel diameter data 960 as data.

  The pattern definition data 920 is data in which a detection pattern of a reflected wave from the lumen-intima boundary is defined, and includes, for example, data of a table as shown in FIG.

  The relative angle determination data 930 is data used to determine the relative angle between the ultrasonic beam and the measurement target blood vessel. For example, as shown in FIG. 8, this includes a table that defines the correlation between the relative angle and the wall thickness increase rate, and data of a correlation formula that formulates the correlation.

  The initial calibration data 940 is data calculated in the initial calibration process, and includes data such as a reference wall thickness and a reference outer membrane position distance.

  The wall thickness data 950 is data on the wall thickness of the blood vessel to be measured measured by the wall thickness measuring unit 330. For example, the measured wall thickness is stored in time series.

  The blood vessel diameter data 960 is data of the blood vessel diameter calculated by the blood vessel diameter calculating unit 340, and for example, the calculated blood vessel diameter is stored in time series.

4). Processing Flow FIG. 11 is a flowchart showing a flow of main processing executed by the processing unit 300 according to the main program 910 stored in the storage unit 900.

  First, the processing unit 300 performs measurement position alignment (step A1). Specifically, the subject is instructed to mount the probe 10 in an appropriate mounting posture. The subject wears the probe 10 on the measurement target site in an appropriate wearing posture in accordance with an instruction from the apparatus.

  Next, the processing unit 300 starts ultrasonic transmission / reception control by the probe 10 (step A3). Then, the lumen-intima boundary detection unit 310 starts a lumen-intima boundary detection process for detecting a reflected wave from the lumen-intima boundary based on the processing result of the signal processing unit 240 (step A5). A combination of the presence / absence of detection of the reflected wave from the front wall lumen intima boundary and the rear wall lumen intima boundary detected by the lumen-intima boundary detection processing is a detection pattern.

  Next, the processing unit 300 performs an initial calibration process (step A7). Specifically, the processing unit 300 measures the wall thickness of the blood vessel to be measured based on the reception result of the reflected ultrasonic wave, and stores the measured value in the initial calibration data 940 as the reference wall thickness. Also, the focus position is initially set by the electronic focus method. Then, the processing unit 300 measures the distance from the ultrasonic transducer to the outer membrane position of the anterior wall of the blood vessel to be measured, and stores the measured value in the initial calibration data 940 as the reference outer membrane position distance.

  When the initial calibration process is completed, the wall thickness measuring unit 330 starts measuring the wall thickness of the blood vessel to be measured based on the reception result of the ultrasonic wave, and stores the measured value in the wall thickness data 950 as needed (step A9). .

  Next, the processing unit 300 determines a detection result by the lumen-intima boundary detection unit 310 (step A11). When the detection result is “OK” (step A11; OK), the blood vessel diameter calculation unit 340 calculates the blood vessel diameter of the measurement target blood vessel based on the reception result of the ultrasonic wave (step A13).

  Specifically, the distance from the front wall lumen intima boundary to the rear wall lumen intima boundary is calculated based on the result of converting the intensity of the reflected wave of the ultrasonic wave into luminance by the signal processing unit 240. Then, the blood vessel diameter of the blood vessel to be measured is calculated. Then, the calculated blood vessel diameter is stored in the blood vessel diameter data 960 of the storage unit 900. Then, the processing unit 300 controls display of the calculated blood vessel diameter on the display unit 500 (step A15).

  On the other hand, when the detection result by the lumen-intima boundary detection unit 310 is “NG” in step A11 (step A11; NG), the processing unit 300 follows the abnormality processing program 911 stored in the storage unit 900. Processing at the time of abnormality is performed (step A17).

FIG. 12 is a flowchart showing a flow of processing at the time of abnormality.
First, the processing unit 300 determines a detection pattern (step B1). When the detection pattern is “pattern A” (step B1; pattern A), the wall thickness measurement unit 330 determines whether or not the measurement value of the wall thickness of the blood vessel to be measured has changed (step B3). . When it is determined that there is no change in the measured value of the wall thickness (Step B3; No), the processing unit 300 shifts the processing to Step B15.

  On the other hand, when it is determined that the measured value of the wall thickness has changed (step B3; Yes), the processing unit 300 stores the reference wall thickness stored in the initial calibration data 940 and the wall thickness data 950. The wall thickness change rate is calculated using the latest measured value of the wall thickness (step B5). The processing unit 300 determines whether or not the wall thickness has increased based on the calculated wall thickness change rate (step B7). If it is determined that the wall thickness has not increased (step B7; No), the processing unit 300 proceeds to step B15. And migrate the process.

  On the other hand, when it is determined that the wall thickness has increased (step B7; Yes), the processing unit 300 uses the relative angle determination data 930 stored in the storage unit 900 to cope with the wall thickness increase rate. The relative angle to be determined is determined (step B9). Then, the processing unit 300 performs relative angle correction processing based on the determined relative angle (step B11).

  The relative angle correction process is performed by the wall thickness change time control unit 321 controlling the transmission direction of the ultrasonic beam. This is because when the reflected wave from the lumen-intima boundary on the front wall side as detected from the transmitter / receiver is detected and the reflected wave from the lumen-intima boundary on the rear wall side is not detected, the wall thickness This corresponds to causing the control unit 321 at change to function.

  Next, the processing unit 300 determines whether or not the reflected wave from the rear wall lumen intima boundary has been detected (step B13). If it is determined that the reflected wave has been detected (step B13; Yes), the abnormal time process is performed. finish. In addition, when it is determined that it could not be detected (step B13; No), the processing unit 300 shifts the processing to step B15.

  On the other hand, when it is determined in step B1 that the detection pattern is “pattern B” (step B1; pattern B), the processing unit 300 performs irradiation position change processing (step B15). The irradiation position changing process is performed by the transmission / reception control unit 320 controlling the transmission position of the ultrasonic beam by changing the array to be driven and controlled.

  The processing unit 300 determines whether or not a reflected wave from the front wall lumen intima boundary has been detected (step B17), and if it has been detected (step B17; Yes), the abnormal time process ends. . In addition, when it is determined that it has not been detected (step B17; No), the processing unit 300 determines whether or not all the arrays are driven and controlled (step B19), and when there is an undriven array ( Step B19; No), returning to Step B15.

  On the other hand, when it is determined that all the arrays have been drive-controlled (Step B19; Yes), the processing unit 300 performs a recognizable range adjustment process (Step B21). The recognizable range adjustment process is performed by the transmission / reception control unit 320 controlling the focus of the ultrasonic beam. That is, when the outer membrane position distance is shorter than the reference outer membrane position distance stored in the initial calibration data 940, control for shifting the focus position to the back side is performed. Conversely, when the outer membrane position distance is longer than the reference outer membrane position distance, control is performed to shift the focus position to the near side.

  On the other hand, when it is determined in step B1 that the detection pattern is “pattern C” (step B1; pattern C), the processing unit 300 performs an ultrasonic beam angle adjustment process (step B23). Specifically, the transmission / reception control unit 320 controls to change the beam angle of the ultrasonic beam by a predetermined angle.

  The processing unit 300 determines whether or not the reflected wave from the lumen-intima boundary of either the front wall or the rear wall has been detected (step B25), and when it is determined that neither has been detected (step B25) ; No), it returns to step B23. If it is determined that any of them has been detected (step B25; Yes), the processing unit 300 determines the detection pattern of the reflected wave from the lumen-intima boundary (step B27).

  When it is determined that the detection pattern is “pattern A” (step B27; pattern A), the processing unit 300 shifts the processing to step B3. If it is determined that the detection pattern is “pattern B” (step B27; pattern B), the processing unit 300 shifts the processing to step B15.

  Returning to the main process in FIG. 11, after step A15 or A17, the processing unit 300 determines whether or not to end the measurement (step A19). If it is determined that the measurement is not yet finished (step A19; No), the process returns to step A11. When it is determined that the measurement is to be ended (step A19; Yes), the processing unit 300 ends the main process.

5. Operational Effects Ultrasonic waves are transmitted and received from the probe 10 which is an ultrasonic wave transmission / reception unit having a plurality of ultrasonic transducers. The lumen-intima boundary detection unit 310 detects a reflected wave from the lumen-intima boundary of the measurement target blood vessel based on the reception result of the ultrasonic wave. The transmission / reception control unit 320 controls the probe 10 so that the reflected wave from the lumen-intima boundary can be detected by the lumen-intima boundary detection unit 310. The blood vessel diameter calculation unit 340 calculates the blood vessel diameter of the blood vessel to be measured based on the reception result of the ultrasonic waves.

  Depending on the relative positional relationship and orientation between the probe 10 and the blood vessel to be measured, it may be impossible for the lumen-intima boundary detection unit 310 to detect a reflected wave from the lumen-intima boundary. Therefore, the transmission / reception control unit 320 controls the probe 10 so that the reflected wave from the lumen-intima boundary can be detected. Thereby, it is possible to always capture the reflected wave from the lumen intima boundary, and the blood vessel diameter calculation unit 340 can accurately measure the blood vessel diameter of the blood vessel to be measured based on the position of the lumen intima boundary. It becomes possible.

  Even if a reflected wave from the front wall lumen intima boundary is detected, a reflected wave from the rear wall lumen intima boundary may not be detected. The reverse is also possible. Therefore, in this embodiment, according to the detection pattern that is a combination of the presence / absence of detection of the reflected wave from the front wall lumen intima boundary and the detection presence / absence of the reflected wave from the rear wall lumen intima boundary, Change the control details. As a result, the probe can be controlled accurately.

  When the reflected wave from the front wall lumen intima boundary is detected but the reflected wave from the rear wall lumen intima boundary is not detected (pattern A), the main factors are the ultrasonic beam and the blood vessel to be measured. The change of the relative angle with can be considered. Therefore, in this case, when there is a change in the wall thickness measured by the wall thickness measuring unit 330 before and after detection of the reflected wave from the intima boundary of the rear wall lumen becomes impossible, transmission of the ultrasonic beam is performed. The relative angle is corrected by controlling the direction. Thereby, it can control so that an ultrasonic beam is irradiated perpendicularly | vertically with respect to the major axis direction of the blood vessel to be measured.

  When the reflected wave from the posterior wall lumen intima boundary is detected but the reflected wave from the anterior wall lumen intima boundary is not detected (pattern B), the main factor is the flatness of the anterior wall of the blood vessel. It is conceivable that the missing position became the irradiation position of the ultrasonic beam. Therefore, in this case, the irradiation position of the ultrasonic beam is changed by controlling the transmission position of the ultrasonic beam. Thereby, it can control so that an ultrasonic beam is irradiated to the flat position of the blood vessel to be measured.

  In addition, when neither the reflected wave from the front wall lumen intima boundary nor the rear wall lumen intima boundary is detected (pattern C), the main factor is the relative angle between the ultrasonic beam and the blood vessel to be measured. Major changes are possible. Therefore, in this case, the beam angle of the ultrasonic beam is adjusted by preferentially controlling the transmission direction of the ultrasonic beam. Thereby, it is possible to control so that a reflected wave from at least one of the front wall lumen intima boundary and the rear wall lumen intima boundary is detected.

6). Modifications Embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit of the present invention. Hereinafter, modified examples will be described.

6-1. Application Example The ultrasonic measurement device 1 according to the above-described embodiment can be used by being incorporated in, for example, a blood pressure measurement device that measures the blood pressure of a subject. It is known that there is a certain non-linear correlation between blood vessel diameter and blood pressure. Therefore, data (for example, a correlation table or correlation formula) that defines the correlation between the blood vessel diameter and the blood pressure is stored in the storage unit 900 in advance, so that the ultrasonic measurement apparatus 1 of the above embodiment is used. The blood pressure of the subject can be calculated from the measured blood vessel diameter. The calculated blood pressure (the calculated value of the blood pressure) is notified to the subject, for example, by being displayed on the display unit 500.

6-2. In the above-described embodiment, the main body device 20 of the ultrasonic measurement device 1 used by hanging from the subject's neck has been described as an example, but this is only an example. For example, it may be configured to be used by being wrapped around the upper arm portion of the subject, or may be configured to be used by being worn on the wrist of the subject. In addition, the probe 10 and the main body device 20 are not necessarily separate from each other, and the probe 10 and the main body device 20 may be provided in the same housing.

  Further, in the above-described embodiment, an ultrasonic measurement apparatus is intended for a subject under free action to measure a blood vessel diameter by an individual. The device is not limited to this. For example, the present invention can be applied to an ultrasonic measurement apparatus in which a technician performs ultrasonic diagnosis on a subject in a lying state using the probe 10 as a medical ultrasonic measurement apparatus.

6-3. Probe In the above-described embodiment, the probe used by being wound around the measurement target site of the subject using the stretchable annular strip 15 has been described as an example. However, the configuration of the probe is not limited thereto. Absent. For example, the probe may be coated with an adhesive solid gel or the like, and the subject may use the probe by attaching the probe to the measurement target site. In addition, it is good also as a structure affixed using an adhesive tape.

  Further, the configuration of the ultrasonic transducer constituting the probe may be a linear configuration that performs linear electronic scanning or a sector configuration that performs sector electronic scanning. Further, it may be a convex type configuration that performs convex electronic scanning.

  In the above embodiment, the probe 110 and the transmission / reception circuit unit 120 are described as being provided in the probe 10. However, the probe 110 and the transmission / reception circuit unit 120 may be separated. is there. Specifically, the probe 10 may be provided with the probe 110 and the main body device 20 may be provided with the transmission / reception circuit unit 120.

  In the above embodiment, the change of the array for driving and controlling the change of the transmission position of the ultrasonic beam with respect to the blood vessel to be measured is realized, but the method of changing the transmission position of the ultrasonic beam is not limited to this. . For example, it is possible to adopt a configuration in which the subject manually changes the transmission position of the ultrasonic beam.

  FIG. 13 is a diagram illustrating a configuration of the probe 30 in the modification, and is a plan view of the probe 30. The probe 30 is mainly composed of a frame body 31 and a sensor section 33, and the sensor section 33 is movable in the left-right direction in a slide groove 35 formed in an opposing portion of the upper frame and the lower frame of the frame body 31. It is inserted.

  In the configuration of the probe 30, the subject manually slides the sensor unit 33 to change the relative position of the ultrasonic transducer with respect to the blood vessel to be measured. For example, when the detection pattern is pattern B, the processing unit 300 instructs the subject to slide the sensor unit 33 in the left-right direction. As an instruction method, a message instructing to slide the sensor unit 33 may be displayed on the display unit 500, or voice guidance may be output from the sound output unit 600. In accordance with instructions from the apparatus, the subject changes the transmission position of the ultrasonic beam by manually sliding the sensor unit 33.

6-4. Control of transmission direction of ultrasonic beam In the above embodiment, when a reflected wave from the front wall lumen intima boundary is detected and a reflected wave from the rear wall lumen intima boundary is not detected (pattern) In the case of A), it has been described that the control unit 321 at the time of changing the wall thickness functions to control the transmission direction of the ultrasonic beam. However, this control is merely an example and can be changed as appropriate.

  For example, when a reflected wave from the rear wall lumen intima boundary is detected and a reflected wave from the front wall lumen intima boundary is not detected (in the case of pattern B), the wall thickness change time control unit It is good also as making 321 function. Further, when the reflected wave from the front wall lumen intima boundary and the rear wall lumen intima boundary is not detected (in the case of pattern C), the wall thickness change control unit 321 may be caused to function. Good.

6-5. Relative angle correction In the above embodiment, it has been described that the data for correcting the relative angle (relative angle correction data) is stored in the storage unit in advance. However, the relative angle correction data is generated in the initial calibration process. It is good to do.

  In this case, in the initial calibration process, the change in the wall thickness of the measurement target blood vessel is measured while changing the beam angle of the ultrasonic beam from the state in which the measurement target blood vessel is vertically irradiated with the ultrasonic beam. At this time, since the wall thickness of the blood vessel to be measured also changes due to pulsation, it is preferable to measure several wall thicknesses at the time of dilatation blood pressure (when the diameter fluctuation becomes the minimum value). At this time, it is effective to measure the wall thickness in a relatively short time in consideration of the change in blood pressure over time.

  DESCRIPTION OF SYMBOLS 1 Ultrasonic measuring device, 10 probe, 15 strip | belt-shaped part, 20 main body apparatus, 23 neck strap, 24 operation button, 25 liquid crystal display, 26 speaker, 110 probe, 120 transmission / reception circuit part, 220 detection part, 240 signal processing Unit, 300 processing unit, 400 operation unit, 500 display unit, 600 sound output unit, 700 communication unit, 800 clock unit, 900 storage unit

Claims (5)

An ultrasonic transmission / reception unit having a plurality of ultrasonic transducers arranged in an array ; and
Based on the reception result of the ultrasonic wave, a detection unit that detects a reflected wave from a lumen-intima boundary of a blood vessel to be measured;
A control unit for changing the transmission direction of the ultrasonic beam by controlling the driving timing of each said ultrasonic transducer before Symbol transceiver,
A wall thickness measuring unit that measures the wall thickness of the blood vessel to be measured based on the reception result of the ultrasonic wave;
A blood vessel diameter calculating unit that calculates a blood vessel diameter of the measurement target blood vessel based on the reception result of the ultrasonic wave ,
When the wall thickness measured by the wall thickness measuring unit is changed before and after the detection becomes impossible, the control unit detects the ultrasonic beam by the transmission / reception unit. An ultrasonic measurement apparatus that repeatedly changes the transmission direction by a predetermined angle until detection of the transmission direction becomes possible . The control unit controls any of a transmission position, a focus, and a transmission direction of the ultrasonic beam by the transmission / reception unit,
The ultrasonic measurement apparatus according to claim 1. Before SL control section, when the wall thickness is increased, and calculates the angle of the transmission direction of the ultrasonic beam to counteract the increased changing the transmission direction of the ultrasonic beam in said angle,
The ultrasonic measurement apparatus according to claim 1 or 2 . When the control unit detects a reflected wave from the lumen-intima boundary on the front wall side when viewed from the transmission / reception unit, and does not detect a reflected wave from the lumen-intima boundary on the rear wall side The transmission direction of the ultrasonic beam is repeatedly changed by the predetermined angle until a reflected wave from the lumen-intima boundary on the rear wall side is detected.
The ultrasonic measurement apparatus according to any one of claims 1 to 3 . A method for controlling an ultrasonic measurement apparatus including an ultrasonic transmission / reception unit having a plurality of ultrasonic transducers arranged in an array ,
Detecting a reflected wave from the lumen-intima boundary of the blood vessel to be measured based on the reception result of the ultrasonic wave;
And changing the transmission direction of the ultrasonic beam by controlling the driving timing of each said ultrasonic transducer before Symbol transceiver,
Measuring the wall thickness of the blood vessel to be measured based on the reception result of the ultrasonic wave;
Calculating a blood vessel diameter of the measurement target blood vessel based on the reception result of the ultrasonic wave;
If the wall thickness measured before and after the detection becomes impossible and the measurement becomes impossible, the transmission direction of the ultrasonic beam is repeated by a predetermined angle until the detection becomes possible. Changing it,
Control method.

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