JP2015223322A - Ultrasonic measuring device and ultrasonic measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a desired region of a tracking object can be different from an actually tracked region.SOLUTION: An ultrasonic transmitting/receiving part 102 transmits an ultrasonic wave to a blood vessel and receives a reflection wave. A first timing detection part 233 detects a first timing corresponding to a diastolic phase. A setting part 232 sets a signal range in which a signal portion for tracking the movement of a blood vessel wall of the blood vessel accompanying the beating of reception signals of the reflection wave acquired at the first timing, and a template of the signal waveform in the signal range. Hereafter, a detection part 239 detects a second timing at which the signal waveform of a signal portion corresponding to the signal range of the reception signals, and the template of the signal waveform satisfy a predetermined condition. Then, a tracking part 210 starts tracking from the second timing.

Description

  The present invention relates to an ultrasonic measurement apparatus and the like that measure by ultrasonic waves.

  As an example of measuring biological information with an ultrasonic measurement device, evaluation of vascular function and determination of vascular disease are performed. In any case, when a blood vessel is a measurement target, the change in the blood vessel diameter associated with the pulsation, that is, the position of the blood vessel wall is tracked and the temporal displacement of the blood vessel wall is often measured. The tracking technique of the displaced part is generally called “tracking”.

  As a tracking method, an echo tracking method based on an image obtained by ultrasonic transmission / reception (see, for example, Patent Document 1) or a phase difference tracking method based on phase information of an ultrasonic signal to be transmitted / received (for example, see Patent Document 2). Etc. are known.

JP 2007-68731 A Japanese Patent Laid-Open No. 10-5226

  Regardless of which tracking method is employed, it is necessary to designate a portion to be tracked before starting tracking. However, according to the conventional method, there may be a case where the desired tracking target portion and the actually tracked portion are different.

  This will be specifically described. For example, consider a case where a measurer designates an image portion of a blood vessel wall as a tracking target while viewing a cross-sectional image of a living body including a blood vessel obtained by ultrasonic transmission and reception, and inputs a tracking start instruction. In this case, the first problem is that it is difficult to specify the tracking target itself because the blood vessel wall is displaced with the pulsation. Next, even if the image portion of the blood vessel wall can be specified, there is a time difference until the tracking is actually started, so tracking may be performed for an image portion different from the specified image portion. . Such a problem is particularly a problem when a fine local part of the blood vessel wall is designated and it is desired to measure a highly accurate displacement of the local part.

  Note that a method of storing an image obtained by ultrasonic transmission / reception as a moving image and playing it back and tracking it by using a pause or the like can be considered, but naturally it cannot be used when tracking in real time.

  Further, in Patent Document 1, for a reference beam and a related beam among a plurality of ultrasonic beams, the position on the related beam corresponding to the tracking point set to the reference beam is determined from the correlation between the echo signals of each other. The technology of diverting and setting is disclosed. However, in the first place, it is clear that there is the above-mentioned problem in setting the tracking point on the reference beam.

  The blood vessel diameter expands and contracts with pulsation. For this reason, the above-described problem becomes more apparent when the tracking target designation timing corresponds to a large displacement time of the blood vessel wall.

  In view of such circumstances, the present invention has been devised for the purpose of solving the problem that a desired tracking target part and an actually tracked part may be different.

  A first invention for solving the above-described problems is a first transmitter / receiver that transmits an ultrasonic wave to a blood vessel and receives the reflected ultrasonic wave as a reflected wave, and the blood vessel corresponds to a diastole. And a setting unit for setting a signal waveform template of a signal related to the movement of the blood vessel wall of the blood vessel among the reflected wave reception signals obtained at the first timing. And a detection unit that detects, as a second timing, a timing at which the received signal of the reflected wave is obtained when a signal waveform of the signal included in the received signal of the reflected wave and the signal waveform template satisfy a predetermined condition And a tracking unit that starts tracking the blood vessel wall of the blood vessel from the second timing.

  As another invention, transmitting an ultrasonic wave to a blood vessel and receiving the reflected ultrasonic wave; detecting that the blood vessel has reached a first timing corresponding to a diastole; Setting a signal waveform template of a signal related to movement of a blood vessel wall of the blood vessel among the received signals of the reflected wave obtained at the first timing; and the signal included in the received signal of the reflected wave Detecting a timing at which the received signal of the reflected wave is obtained, in which a signal waveform and the signal waveform template satisfy a predetermined condition, as a second timing, and tracking of the blood vessel wall from the second timing It is good also as comprising comprising starting.

  According to the first aspect of the invention, a signal waveform template of a signal related to movement of the blood vessel wall of the blood vessel is set out of the reception signals of the reflected ultrasonic waves transmitted toward the blood vessel. This setting is performed based on the received signal obtained at the first timing. Therefore, since it can set based on the received signal of a certain moment like a still image, the desired tracking object can be set exactly.

  Then, after setting the tracking target, the second timing in which the signal waveform of the received signal and the set signal waveform template satisfy a predetermined condition is detected. Tracking is started at this second timing. In addition, the first timing is a diastole period in which there is little change in the position of the blood vessel wall. Therefore, the second timing is also in the diastole period. Therefore, there is no problem even if there is a time difference between the first timing and the second timing, and the possibility that the desired tracking target part and the actually tracked part are different is extremely low.

  A second invention is the ultrasonic measurement device according to the first invention, wherein the timing detection unit detects the first timing by pre-tracking the reception signal of the reflected wave.

  According to the second invention, the first timing can be detected by pre-tracking the reception signal of the reflected wave of the ultrasonic wave transmitted toward the blood vessel.

  According to a third invention, in the second invention, the timing detection unit detects, as the first timing, a timing at which a displacement of a peak waveform portion included in the received signal satisfies a predetermined condition. Device.

  According to the third aspect of the invention, for example, the timing when the displacement of the peak waveform portion included in the received signal is small can be detected as the first timing.

  In a fourth aspect based on the third aspect, the timing measurement unit detects the first timing based on the displacement of the peak waveform portion appearing at the position of the outer membrane portion of the blood vessel. It is.

  According to the fourth aspect of the invention, the first timing can be detected based on the displacement of the peak waveform portion appearing at the position of the outer membrane portion of the blood vessel.

  A fifth invention is the ultrasonic measurement device according to the second invention, wherein the timing detector detects the first timing by measuring a change in the diameter of the blood vessel by the pre-tracking.

  According to the fifth aspect of the invention, the first timing can be detected based on the change in blood vessel diameter.

  In a sixth aspect based on the first aspect, the transmission / reception unit performs the reception at a predetermined frame rate, and the timing detection unit correlates the received signal of the preceding and succeeding frames with a predetermined condition. This is an ultrasonic measurement device that detects the timing satisfying as the first timing.

  According to the sixth aspect of the invention, the first timing can be detected based on the correlation value of the received signal received in the preceding and succeeding frames.

  A seventh aspect of the invention is the ultrasonic measurement according to any one of the first to sixth aspects, wherein the timing detection unit detects a timing at the end of diastole in the diastole as the first timing. Device.

  According to the seventh aspect, the timing at the end of the diastole can be detected as the first timing.

  In addition, in an eighth invention according to any one of the first to seventh inventions, the setting section includes a signal range template for anterior wall and a signal waveform template for anterior wall related to a signal portion of the anterior wall of the blood vessel, A signal range for a rear wall and a signal waveform template for a rear wall relating to a signal portion of a wall are set, and the detection unit includes a signal waveform of the signal portion corresponding to the signal range for the front wall and the signal waveform template for the front wall. And the timing when the signal waveform of the signal portion corresponding to the signal range for the rear wall and the signal waveform template for the rear wall satisfy the condition is detected as the second timing. It is a sound wave measuring device.

  According to the eighth invention, the technique of any one of the first to seventh inventions is applied to each of the front wall and the rear wall of the blood vessel, the condition is satisfied for the front wall, and the condition for the rear wall is also satisfied. The satisfied timing is set as the second timing. The amount of displacement of the front wall and the amount of displacement of the rear wall due to pulsation may vary depending on the blood vessel to be subjected to ultrasonic measurement, its position, and the subject. However, even if the displacement amount of one of the front wall and the rear wall is small, the displacement amount of the other is large. Therefore, as in the eighth aspect of the invention, by applying the above-described technique of the invention to the front wall and the rear wall, the accuracy of matching between the desired tracking target part and the actually tracked part is improved. Can be made.

The figure which shows the system structural example of an ultrasonic measurement apparatus. The figure for demonstrating the principle of this embodiment. The figure for demonstrating the principle of this embodiment. The flowchart which shows an example of the flow of a process which detects 1st timing. The flowchart which shows an example of the flow of a process which detects 1st timing. The flowchart which shows an example of the flow of a process which detects 1st timing. The flowchart which shows an example of the flow of a process which detects 1st timing. The figure which shows the function structural example of an ultrasonic measurement apparatus. The figure which shows the specific example of the setting of a signal range and a signal waveform template. The figure which shows the structural example of a memory | storage part. The flowchart which shows the flow of a measurement process.

  Hereinafter, an example of an embodiment to which the present invention is applied will be described, but an embodiment to which the present invention can be applied is not limited to the following embodiment.

  FIG. 1 is a diagram illustrating a system configuration example of an ultrasonic measurement apparatus 10 according to the present embodiment. The ultrasonic measurement device 10 is a device that measures biological information of the subject (subject) 2 by measuring a reflected wave of ultrasonic waves. In this embodiment, vascular system function information such as blood pressure related to a blood vessel 4 which is an artery and IMT (Intima Media Thickness) is measured as one of biological information. In the illustrated example, the carotid artery is the blood vessel 4 to be measured, but other arteries such as the radial artery may be the blood vessel 4 to be measured.

  The ultrasonic measurement apparatus 10 includes a touch panel 12 that also serves as a means for displaying an image of measurement results and operation information and a means for operation input, a keyboard 14 for performing operation input, and an ultrasonic probe 16 (probe). ) And the processing device 30. A control board 31 is mounted on the processing apparatus 30 and is connected to various parts of the apparatus such as the touch panel 12, the keyboard 14, and the ultrasonic probe 16 so as to be able to send and receive signals.

  The control board 31 includes a CPU (Central Processing Unit) 32, an ASIC (Application Specific Integrated Circuit), various integrated circuits, a storage medium 33 such as an IC memory or a hard disk, and communication for realizing data communication with an external device. IC 34 is mounted. The processing device 30 executes a measurement program stored in the storage medium 33 by the CPU 32 or the like, thereby performing control to start tracking of the blood vessel wall of the blood vessel 4 related to ultrasonic measurement, and a blood vessel targeted for the blood vessel 4 Various functions according to the present embodiment such as measurement of system function information are realized.

  Specifically, under the control of the processing device 30, the ultrasonic measurement device 10 transmits and irradiates an ultrasonic beam from the ultrasonic probe 16 to the subject 2 and receives the reflected wave. Then, by performing signal processing on the received signal of the reflected wave (hereinafter simply referred to as “received signal”), it is possible to generate reflected wave data such as position information of the living body structure of the subject 2 and changes with time. The reflected wave data includes images of so-called A mode, B mode, M mode, and color Doppler modes. Measurement using ultrasonic waves is repeatedly executed at a predetermined cycle. The unit of measurement is called “frame”.

  In addition, the ultrasonic measurement apparatus 10 sets a tracking point (region of interest) as a reference received signal, thereby tracking the tracking point in time series between different frames to calculate displacement, so-called “tracking”. It can be carried out. In the present embodiment, the front wall and the rear wall of the blood vessel 4 are used as tracking points, but the ultrasonic measurement apparatus 10 has a feature in setting and starting control of the tracking points.

[Description of Principle]
The principle of tracking point setting and start control will be described.
FIG. 2 is a diagram showing an outline of reflected wave data obtained by signal processing of a received signal. (1) is a time axis, (2) is a schematic M-mode image related to the front wall, and (3) is a rear wall. (4) shows a schematic A mode image related to the front wall, and (5) shows a schematic A mode image related to the rear wall. Since the A-mode image can be said to be a received signal, the following description will be made synonymously with the received signal. In the ultrasonic measurement, reflected waves from the front wall and the rear wall of the blood vessel 4 are detected strongly. The signal portion of the received signal shown in FIGS. 2 (4) and 2 (5) is a signal portion having a certain depth range obtained by cutting out a peripheral portion including signal portions from the front wall and the rear wall.

  The front wall and the rear wall of the blood vessel 4 are displaced back and forth (in the depth direction) as viewed from the ultrasonic probe 16 along with the pulsation. For this reason, when attention is paid to the front wall portion and the rear wall portion of the reflected wave signal, they are displaced as shown in FIGS. Time t11 to t14 is one beat. However, the front wall and the rear wall are displaced, but return to the same position after one beat. For example, in FIG. 2 (5), the peak of the rear wall appears at substantially the same depth position in the signal waveform at time t11 and the signal waveform at time t14. Of course, a peak appears at substantially the same position (same depth position) not after one beat but also after an integer beat. In this embodiment, tracking start control is performed using this.

  First, a target to be tracked is designated / set from the received signal obtained at the first timing. In other words, since a tracking target can be set from the received signal obtained at the first timing as a still image, for example, the received signal can be set precisely by enlarging the received signal. FIG. 2 (5) shows an example in which the rear wall is a tracking target. Time t11 is the first timing. Of the received signal at time t11, a depth range including the signal portion of the rear wall is set as a signal range (depth range) desired as a tracking target. It is an area surrounded by a thick solid line. A signal waveform within this signal range is set as a template waveform.

  When the setting of the signal range is completed, the received signal acquired in real time is continuously monitored thereafter. Specifically, the correlation calculation between the signal waveform within the signal range of the received signal and the template waveform is repeatedly performed to detect the arrival of the second timing at which the correlation value satisfies the threshold condition. That is, the second timing in which the signal waveform within the signal range of the received signal satisfies the corresponding condition corresponding to the template waveform is continuously monitored. Tracking is started at this second timing.

  FIG. 2 (6) shows the change of the correlation value. The timing when the correlation value is equal to or greater than the threshold is detected as the second timing. Time t14 is the second timing. As shown in FIG. 2 (5), at the time t14, the rear wall is located at the same depth position as the time t11 which is the first timing. Therefore, the desired tracking target portion and the actually tracked portion do not differ. In addition, since tracking is started from the received signal acquired at the second timing (time t14), the tracking point (region of interest) is set from the received signals acquired at the second timing. Specifically, tracking is started using the signal portion of the signal range in the received signal acquired at the second timing as a tracking point (region of interest).

  The tracking target may be only one of the front wall and the rear wall, but in the present embodiment, both are designated and set. This is because the displacement amount of one of the front wall and the rear wall is large, but the displacement amount of the other may be small. This event occurs due to a vascular property, a tissue around the blood vessel, or the like, and may be caused by a blood vessel to be measured, a measurement position, or a subject. FIG. 3 shows an example in which one of the front wall and the rear wall has a large displacement and the other has a small displacement. FIG. 3 shows a case where the displacement amount of the front wall is small and the displacement amount of the rear wall is large. The way of viewing the figure is the same as in FIG.

  In FIG. 3, the depth position of the front wall is substantially the same regardless of the pulsation. Therefore, as shown in FIG. 3 (6), the correlation value related to the front wall is a substantially constant value, and the second timing that is equal to or greater than the threshold value TH can arrive before time t24. By specifying and setting both the front wall and the rear wall as tracking targets, the second timing can be detected more accurately.

Next, the timing of the first timing will be described.
Although the signal range and the template waveform may be set with the first timing as an arbitrary timing, the blood vessel wall is displaced with the pulsation. Therefore, the second timing can be detected more accurately by determining the time when the blood vessel wall is not displaced or when the displacement is small and determining the first timing.

The period when the displacement of the blood vessel wall is small is the diastole period, particularly the end diastole period. A method of determining this time and detecting it as the first timing will be described with reference to the drawings.
FIG. 4 is a diagram illustrating an example of a flow of processing for detecting the first timing, and is a diagram illustrating a first processing example. In the first processing example, first, the position of the blood vessel wall is detected from the received signal of the reflected wave (step A1). In other words, the position of the blood vessel wall is pre-tracked. The blood vessel wall to be detected may be either the front wall or the rear wall, or both. In order to improve accuracy, both are preferable. Next, the displacement amount of the blood vessel wall is calculated in successive frames (step A3). The timing at which the amount of displacement satisfies a predetermined small displacement condition, that is, the timing when the displacement is equal to or less than the threshold (step A5) is detected as the first timing (step A7). The diastole is a technique that utilizes the small amount of displacement of the blood vessel wall. It is also possible to detect the end of diastole period depending on the threshold value in step A5.

  FIG. 5 is a diagram illustrating a second processing example. In the second processing example, first, the position of the blood vessel is detected from the received signal of the reflected wave (step B1). In other words, the blood vessel position is pre-tracked. Next, correlation calculation is performed on the signal of the blood vessel portion in the received signal in successive frames (step B3). The timing at which the correlation value satisfies a predetermined high correlation condition, that is, the timing at which the correlation value is equal to or greater than the threshold (step B5) is detected as the first timing (step B7). The diastole is a technique that utilizes the fact that the correlation between the received signals of different frames is high because the displacement of the blood vessel is small. It is also possible to detect the end of diastole period depending on the threshold value in step B5.

  FIG. 6 is a diagram illustrating a third processing example. In the third processing example, the ultrasonic measurement apparatus 10 inputs an ECG (Electrocardiogram) signal (electrocardiogram signal) of the subject 2 from the outside (step C1), and detects the rise time Tr of the R wave appearing in the ECG signal. (Step C3). Then, a predetermined time (for example, several ms) from the detected time Tr is detected as the first timing (steps C5 and C7). This is a technique utilizing the fact that the diastole can be determined based on the R wave of the ECG signal. Depending on the setting of the determination period based on time Tr, it is also possible to detect the end of diastole.

  FIG. 7 is a diagram illustrating a fourth processing example. In the fourth processing example, first, the epicardial position is detected from the received signal of the reflected wave (step D1). In other words, the position of the adventitia is pre-tracked. Next, the standard deviation σ of the outer membrane detection position for the past M frames from the present is calculated (step D3). Then, the timing at which the standard deviation σ satisfies a predetermined small displacement condition, that is, the timing when the standard deviation σ is equal to or less than the threshold (step D5) is detected as the first timing (step D7). During diastole, this technique utilizes the fact that variations in the position of the adventitia remain within a certain level. It is also possible to detect the end of diastole depending on the threshold value in step D5.

[Description of functional configuration]
Next, a functional configuration for realizing the present embodiment will be described.
FIG. 8 is a block diagram illustrating a functional configuration example of the ultrasonic measurement apparatus 10 according to the present embodiment. The ultrasonic measurement apparatus 10 includes an operation input unit 100, an ultrasonic transmission / reception unit 102, a processing unit 200, a display unit 300, and a storage unit 500.

  The operation input unit 100 receives various operation inputs from the measurer and outputs an operation input signal corresponding to the operation input to the processing unit 200. The operation input unit 100 can be realized by a button switch, a lever switch, a dial switch, a track pad, a mouse, or the like. In the example of FIG. 1, the touch panel 12 and the keyboard 14 correspond to this.

  The ultrasonic transmission / reception unit 102 transmits ultrasonic waves with the pulse voltage output from the processing unit 200. Then, the transmitted reflected wave of the ultrasonic wave is received, converted into an electric signal, and output to the processing unit 200. The ultrasonic probe 16 in FIG. 1 corresponds to this.

  The processing unit 200 is realized by, for example, a microprocessor such as a CPU or a GPU (Graphic Processor Unit), or an electronic component such as an ASIC, an FPGA (Field-Programmable Gate Array), or an IC (Integrated Circuit) memory. The processing unit 200 performs input / output control of data with each functional unit, and based on a predetermined program and data, an operation input signal from the operation input unit 100, a signal from the ultrasonic transmission / reception unit 102, and the like. Various types of arithmetic processes are executed to calculate biological information of the subject (subject) 2. The processing apparatus 30 and the control board 31 in FIG.

  The processing unit 200 includes an ultrasonic control unit 202, a tracking unit 210, a tracking start control unit 230, a front and rear wall detection unit 244, a vascular system function measurement control unit 248, a measurement result record display control unit 250, an image A generating unit 260.

  The ultrasonic control unit 202 controls transmission of ultrasonic waves toward the blood vessels and reception of reflected waves. For example, it has a drive control unit 204, a transmission / reception control unit 206, and a reception signal synthesis unit 208, and controls ultrasonic measurement in an integrated manner. The ultrasonic control unit 202 can be realized by a known technique.

  The drive control unit 204 controls the transmission timing of the ultrasonic pulse from the ultrasonic probe 16 and outputs a transmission control signal to the transmission / reception control unit 206.

  The transmission / reception control unit 206 generates a pulse voltage according to the transmission control signal from the drive control unit 204 and outputs the pulse voltage to the ultrasonic transmission / reception unit 102. At that time, transmission delay processing can be performed to adjust the output timing of the pulse voltage to each ultrasonic transducer. In addition, amplification and filtering of the signal output from the ultrasonic transmission / reception unit 102 can be performed, and the result can be output to the reception signal synthesis unit 208.

  The reception signal synthesis unit 208 performs a delay process or the like as necessary to execute a process related to the focus of the reception signal and the like to generate reflected wave data 510 (see FIG. 10) including the reception signal data 516. The reflected wave data 510 is used by the tracking start control unit 230 and the tracking unit 210.

  The tracking start control unit 230 is a functional unit that performs the above-described tracking start control, and includes a setting unit 232, an extraction unit 237, a correlation calculation unit 238, and a detection unit 239. In the present embodiment, the processing unit 200 reads and executes the tracking start control program 502 (see FIG. 10) to implement the tracking start control unit 230 as software. However, the processing unit 200 implements hardware using an electronic circuit such as an FPGA. It may be realized as wear. The extraction unit 237, the correlation calculation unit 238, and the detection unit 239 may be configured by an electronic circuit such as an FPGA.

  The setting unit 232 is a functional unit that sets a tracking target, and in the depth direction of the received signal in accordance with the first timing detection unit 233 for detecting the first timing and the operation input of the operation input unit 100. A signal range setting unit 234 that sets the position range (signal range) of the signal, and a template setting unit 236 that sets a signal waveform within the signal range of the received signal as a signal waveform template. The first timing detection unit 233 is a functional unit that detects the first timing using any of the methods described with reference to FIGS. A threshold condition (such as a predetermined small displacement condition) for determining the first timing is stored as first determination condition data 518 in the storage unit 500.

  The signal range setting unit 234 sets a signal range for each of the front wall and the rear wall from the received signal at the first timing, and the signal range data for the front wall 521a and the signal range data for the rear wall 521b (inclusively) (Referred to as “signal range data 521”) is stored in the storage unit 500 (see FIG. 10). Similarly, the template setting unit 236 sets the signal waveform templates for the front wall and the rear wall, and the signal waveform template for the front wall 523a and the signal waveform template for the rear wall 523b (inclusively, “signal waveform template 523”). Is stored in the storage unit 500.

  The setting of the signal range and the signal waveform template will be described more specifically with reference to FIG. FIG. 9 shows an example of the reflected wave signal obtained at the first timing. For example, the setting unit 232 displays the received signal on the display unit 300, and in accordance with the setting instruction operation from the operation input unit 100, the front wall signal range FW (521a) and the rear wall signal range RW (521b). ) And set. Each of the signal ranges (front wall signal range FW and rear wall signal range RW) is data defining a range of depth positions. In setting the signal range, it is possible to set the range accurately, for example, by enlarging the received signal.

  When the setting of the signal range is completed, the setting unit 232 cuts out the signal portion in the front wall signal range FW and sets it as the front wall signal waveform template FT (523a), and the signal portion in the rear wall signal range RW. Are cut out and set as the front wall signal waveform template RT (523b).

Returning to FIG. The extraction unit 237, the correlation calculation unit 238, and the detection unit 239 function to detect the arrival of the second timing.
The extraction unit 237 extracts a signal part in the front wall signal range FW and a signal part in the rear wall signal range RW from the reception signals that are output as needed from the ultrasonic control unit 202, and a correlation calculation unit. Output to H.238.

  The correlation calculation unit 238 performs a correlation calculation between the signal waveform template and the signal portion extracted by the extraction unit 237 for each of the front wall and the rear wall, calculates a correlation value, and outputs the correlation value to the detection unit 239. For the correlation calculation, for example, normalized cross-correlation, zero average normalized cross-correlation, or the like can be used.

  The detection unit 239 detects the arrival of the second timing by detecting whether the correlation value satisfies a corresponding condition, that is, whether the correlation value is equal to or greater than a threshold value. When the arrival of the second timing is detected, a tracking start instruction signal is output to the tracking unit 210.

  The tracking unit 210 starts tracking in response to the tracking start instruction signal from the detection unit 239. The tracking point (region of interest) is set in the signal portion of a predetermined signal range in the received signal when the tracking start instruction signal is input. As a result, a site desired as a tracking target is surely set as a tracking point. A known technique can be applied to the subsequent tracking itself. For example, functions such as “echo tracking” and “phase difference tracking” are realized.

  The front and rear wall detection unit 244 detects blood vessel feature points from the received signal as a pre-stage of setting by the setting unit 232. Specifically, two peaks that are equal to or higher than a predetermined signal intensity and whose signal intensity between the peaks is equal to or lower than a predetermined low intensity indicating blood are detected as a front wall and a rear wall. Of course, the method of detecting the front wall and the rear wall is not limited to this method, and other methods may be adopted.

  The vascular system function measurement control unit 248 determines the displacement of the vascular diameter based on the positions of the front wall and the rear wall of the blood vessel 4 continuously measured by the tracking unit 210, and performs the given vascular system function measurement. Such control is performed. For example, arithmetic control is performed such as performing blood pressure estimation from a blood vessel diameter using a stiffness parameter to measure blood pressure.

  The measurement result recording / display control unit 250 stores the measurement result of the vascular system function in the storage unit 500 and performs control for displaying on the display unit 300.

  The image generation unit 260 generates images for displaying various operation screens and measurement results necessary for ultrasonic measurement and biological information measurement, and outputs them to the display unit 300.

  The display unit 300 displays image data input from the image generation unit 260. The touch panel 12 of FIG. 1 corresponds to this.

  The storage unit 500 is realized by a storage medium such as an IC memory, a hard disk, or an optical disk, and stores various types of data such as various programs and calculation process data of the processing unit 200. In FIG. 1, the storage medium 33 mounted on the control board 31 of the processing apparatus 30 corresponds to this. Note that the connection between the processing unit 200 and the storage unit 500 is not limited to the connection by an internal bus circuit in the apparatus, but may be realized by a communication line such as a LAN (Local Area Network) or the Internet. In that case, the storage unit 500 may be realized by an external storage device different from the ultrasonic measurement device 10.

  Then, as shown in FIG. 10, the storage unit 500 includes a measurement program 501, reflected wave data 510, first timing determination condition data 518, setting data 520, equivalent condition data 530, and vascular function measurement. Data 570 is stored. Of course, in addition to these, frame identification information, various flags, a counter value for timing, etc. can be stored as appropriate.

The processing unit 200 reads out and executes the measurement program 501, thereby performing the ultrasonic control unit 202, the tracking start control unit 230, the front and rear wall detection unit 244, the vascular system function measurement control unit 248, and the measurement result record display control unit 250. The functions of the image generation unit 260 and the like are realized. Further, the measurement program 501 includes a tracking start control program 502 for realizing the function of the tracking start control unit 230 as a subroutine program. Further, the tracking start control program 502 includes a first timing detection program 503 for realizing the function of the first timing detection unit 233 as a subroutine program.
When these functional units are realized by hardware such as an electronic circuit, a part of a program for realizing the functions can be omitted.

  The reflected wave data 510 is reflected wave data obtained by ultrasonic measurement, and is generated for each frame by the ultrasonic control unit 202. One reflected wave data 510 includes, for example, a scanning line ID 512, a measurement frame 514, and received signal data (depth-signal intensity data) 516. Of course, other data can be stored as appropriate.

  The first timing determination condition data 518 is data in which the first timing detection unit 233 determines a condition (such as the threshold described with reference to FIGS. 4 to 7) for determining the first timing.

  The setting data 520 stores signal range data 521 that is data of a signal range set by the setting unit 232 and a signal waveform template 523 based on the received signal at the first timing.

  The equivalent condition data 530 is data that defines the threshold value condition of the correlation value for the detection unit 239 to detect the arrival of the second timing. For example, the threshold value TH in FIGS.

  The vascular system function measurement data 570 includes data in which the positions of the front wall and the rear wall of the blood vessel 4 tracked by the tracking unit 210 are associated with the time information at which the corresponding reception signal is obtained, The blood vessel diameter data calculated from the position, the blood pressure data calculated based on the blood vessel diameter, and the like are stored.

[Description of process flow]
Next, the operation of the measurement process of the ultrasonic measurement apparatus 10 will be described.

FIG. 11 is a flowchart for explaining the flow of measurement processing in the ultrasonic measurement apparatus 10 according to the present embodiment.
In this processing, the processing unit 200 transmits an ultrasonic beam for each ultrasonic transducer (scanning line) of the ultrasonic transmission / reception unit 102, receives the reflected wave, and stores the reflected wave data 510 in the storage unit 500 as needed. It is assumed that the process for storing is started.

  First, based on reception signal data 516 obtained as needed by transmission and reception of ultrasonic waves, the front and rear wall detection unit 244 determines whether or not a feature point is included in the reception signal, thereby detecting the feature point. (Step S1: NO). In the present embodiment, the feature points are peaks indicating the front wall and the rear wall of the blood vessel 4. When the feature point is detected (step S1: YES), the tracking start control unit 230 performs a tracking start control process (steps S2 to S7).

  That is, first, the first timing detector 233 detects the first timing (step S2). As the first timing detection method, any method described with reference to FIGS. If the first timing can be detected (step S2: YES), the setting unit 232 sets the signal range and the signal waveform template using the received signal at the first timing (step S3). Next, the extraction unit 237 extracts signal portions within the signal range of the subsequent received signals as needed, and the correlation calculation unit 238 determines whether or not the signal portions correspond to the signal waveform template by using the corresponding condition data 530. Use to determine. Specifically, the correlation calculation unit 238 performs correlation calculation between the signal portion and the signal waveform template (step S5), and whether or not the correlation value satisfies the corresponding condition (threshold condition), that is, the second timing has arrived. Is determined (step S7). Until the corresponding condition is satisfied (step S7: NO), the processing of steps S5 to S7 is repeated to monitor the arrival of the second timing.

When the corresponding condition is satisfied (step S7: YES), the detection unit 239 outputs a tracking start instruction signal to the tracking unit 210 assuming that the second timing has arrived, and the tracking unit 210 starts tracking (step S9). . Then, the vascular system function measurement control unit 248 starts measuring the vascular system function (step S11).
Thereafter, when an operation for terminating the measurement process is performed (step S13: YES), the measurement process is terminated.

  As described above, according to the present embodiment, the signal portion for tracking the movement of the blood vessel wall of the blood vessel accompanying the pulsation is included in the received signal that has received the reflected wave of the ultrasonic wave transmitted toward the blood vessel 4. A signal range and a signal waveform template in the signal range are set. This setting is performed based on the received signal obtained at the first timing. Therefore, since it can set based on the received signal of a certain moment like a still image, the desired tracking object can be set exactly.

  After the tracking target is set, the arrival of the second timing in which the signal portion corresponding to the set signal range and the set signal waveform template satisfy the predetermined equivalent condition in the received signal is detected. Tracking is started at this second timing. In addition, the first timing is a diastole period in which there is little change in the position of the blood vessel wall. Therefore, the second timing is also in the diastole period. Therefore, although there is a time difference between the first timing and the second timing, the time difference does not matter and the possibility that the desired tracking target part and the actually tracked part are different is extremely low.

  In addition, the form of this invention is not restricted to the said embodiment, A component can be added, abbreviate | omitted, and changed suitably. For example, in the above-described embodiment, it has been described that both the front wall and the rear wall of the blood vessel are set as tracking targets, but it is needless to say that only one of the blood vessels may be set as a tracking target.

Although explained as performing a correlation operation, instead of a similarity such as a correlation value, a square error (Sum of Squared Difference: SSD) or an absolute error (Sum of Absolute Difference) is used.
: SAD) may be used. However, when SSD or SAD is used, the smaller the value, the more similar, and therefore the equivalent condition (threshold condition) is set to be equal to or less than the threshold.

  DESCRIPTION OF SYMBOLS 2 ... Subject, 4 ... Blood vessel, 10 ... Ultrasonic measurement apparatus, 16 ... Ultrasonic probe, 30 ... Processing apparatus, 33 ... Storage medium, 100 ... Operation input part, 102 ... Ultrasonic transmission / reception part, 200 ... Processing part, 202 ... Ultrasonic control unit, 210 ... Tracking unit, 230 ... Tracking start control unit, 233 ... First timing detection unit, 248 ... Vascular system function measurement control unit, 300 ... Display unit, 500 ... Storage unit

Claims (9)

A transmitting / receiving unit that transmits ultrasonic waves to a blood vessel and receives the reflected ultrasonic waves as reflected waves;
A timing detection unit for detecting that the blood vessel has reached a first timing corresponding to a diastole;
Of the received signal of the reflected wave obtained at the first timing, a setting unit for setting a signal waveform template of a signal related to movement of a blood vessel wall of the blood vessel;
A detection unit that detects, as a second timing, a timing at which the received signal of the reflected wave is obtained, wherein the signal waveform of the signal and the signal waveform template included in the received signal of the reflected wave satisfy a predetermined condition;
A tracking unit that starts tracking the blood vessel wall of the blood vessel from the second timing;
An ultrasonic measurement device. The timing detection unit detects the first timing by pre-tracking a reception signal of the reflected wave,
The ultrasonic measurement apparatus according to claim 1. The timing detection unit detects, as the first timing, a timing at which a displacement of a peak waveform portion included in the received signal satisfies a predetermined condition;
The ultrasonic measurement apparatus according to claim 2. The timing detection unit detects the first timing based on a displacement of the peak waveform portion appearing at a position of an outer membrane portion of the blood vessel;
The ultrasonic measurement apparatus according to claim 3. The timing detection unit detects the first timing by measuring a change in the diameter of the blood vessel by the pre-tracking;
The ultrasonic measurement apparatus according to claim 2. The transmission / reception unit performs the reception at a predetermined frame rate,
The timing detection unit detects, as the first timing, a timing at which a correlation value obtained by performing a correlation operation on the received signals of the preceding and succeeding frames satisfies a predetermined condition.
The ultrasonic measurement apparatus according to claim 1. The timing detection unit detects the timing of the end of diastole in the diastole as the first timing;
The ultrasonic measurement apparatus according to any one of claims 1 to 6. The setting unit includes a front wall signal range and a front wall signal waveform template related to the signal portion of the blood vessel front wall, and a rear wall signal range and a rear wall signal waveform template related to the rear wall signal portion. Set,
The detection unit includes a signal waveform of a signal portion corresponding to the signal range for the front wall and a signal waveform template for the front wall satisfying the condition, and a signal waveform of the signal portion corresponding to the signal range for the rear wall. And the timing at which the signal waveform template for the rear wall satisfies the condition is detected as the second timing.
The ultrasonic measurement apparatus according to claim 1. Transmitting ultrasound to the blood vessel and receiving the reflected ultrasound;
Detecting that the blood vessel has reached a first timing corresponding to diastole;
Of the received signals of the reflected wave obtained at the first timing, setting a signal waveform template of a signal related to movement of the blood vessel wall of the blood vessel;
Detecting, as a second timing, a timing at which the received signal of the reflected wave is obtained when a signal waveform of the signal included in the received signal of the reflected wave and the signal waveform template satisfy a predetermined condition;
Starting tracking of the vessel wall from the second timing;
An ultrasonic measurement method including:

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