JP2014111209A - Blood vessel diameter measurement device and blood vessel diameter measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood vessel diameter measurement device capable of correctly measuring the diameter of a blood vessel.SOLUTION: The blood vessel diameter measurement device includes a control circuit for calculating the outer diameter and the inner diameter of a blood vessel on the basis of arrival times from the sending of ultrasonic waves from three ultrasonic arrays 11 to the arrival of the ultrasonic waves at the ultrasonic arrays 11 after reflection against a blood vessel. The control circuit includes: a signal delay circuit for controlling the sending angles of the ultrasonic waves so as to allow the ultrasonic waves to pass the center of the vessel; a reception measurement unit for measuring a first arrival time of a first reflection wave that is reflected against a blood vessel and arrives at the ultrasonic array 11 first and a second arrival time of a second reflection wave that arrives at the ultrasonic array 11 after a predetermined time elapse from the first arrival time; an outer diameter calculation unit for calculating the outer diameter R of a blood vessel on the basis of the first arrival times of the three first reflection waves; and an inner diameter calculation unit for calculating the inner diameter r of a blood vessel on the basis of the second arrival times of the three second reflection waves.

Description

  The present invention relates to a blood vessel diameter measuring device that measures the diameter of a blood vessel in a living body using ultrasonic waves.

2. Description of the Related Art Conventionally, a measuring apparatus that measures the diameter of a blood vessel in a living body using ultrasonic waves is known (see, for example, Patent Document 1).
The measurement apparatus of Patent Document 1 includes an ultrasonic probe in which a first array and a second array are provided in a direction that intersects the axial direction of a blood vessel. Each array has a plurality of ultrasonic elements. In each array, the plurality of ultrasonic elements transmit ultrasonic waves to the blood vessels so as to be parallel to each other, and receive ultrasonic waves reflected by the blood vessels. Thereby, the time from the transmission of the ultrasonic wave to the reception is measured, and the diameter of the blood vessel is calculated based on this time.

Japanese Patent No. 4444164

By the way, when the ultrasonic wave is transmitted from the ultrasonic element in a direction orthogonal to the wall surface of the blood vessel, the intensity of the ultrasonic wave reflected on the wall surface of the blood vessel does not decrease, and the ultrasonic element is reflected. Ultrasonic waves can be received accurately. However, in a measuring apparatus such as Patent Document 1, since ultrasonic waves are transmitted to the wall surface of the blood vessel so that they are parallel to each other, the ultrasonic waves passing through the center of the blood vessel are not orthogonal to the wall surface of the blood vessel. It will be sent. For this reason, the ultrasonic wave transmitted without being orthogonal to the wall surface of the blood vessel has a reduced intensity of the ultrasonic wave reflected by the wall surface of the blood vessel, and the ultrasonic element cannot receive the reflected ultrasonic wave accurately. Thereby, there is a possibility that an accurate blood vessel diameter cannot be measured.
In addition, when the vessel wall is thin or the vessel is contracted, it is impossible to determine whether the reflected ultrasound is reflected by the inner wall or the outer wall of the blood vessel. May not be calculated.

  An object of the present invention is to provide a blood vessel diameter measuring apparatus capable of measuring an accurate blood vessel diameter.

The blood vessel diameter measuring apparatus according to the present invention includes at least three ultrasonic arrays provided on a probe that contacts a living body, and the ultrasonic waves reflected from the blood vessels in the living body after ultrasonic waves are transmitted from the ultrasonic array. A control circuit that calculates an outer diameter and an inner diameter of the blood vessel based on an arrival time until it reaches the array, and the ultrasonic array includes a plurality of ultrasonic elements arranged in one direction along a scanning direction. The control circuit has a timing corresponding to each of the at least three ultrasonic arrays, the timing at which each of the plurality of ultrasonic elements emits an ultrasonic wave in the scanning direction. The transmission angle control unit for controlling the transmission angle of the ultrasonic wave with respect to the scanning direction so that the ultrasonic wave transmitted from the ultrasonic array passes through the center of the blood vessel. The first reflected wave measuring unit that measures the first arrival time of the first reflected wave that is reflected by the blood vessel and reaches the ultrasonic array earliest, and the first arrival time is set as a reference And a second reflected wave measuring unit that measures a second arrival time of the second reflected wave that has reached the ultrasonic array within a predetermined time range, and each of the at least three ultrasonic arrays. An outer diameter calculator that calculates an outer diameter of the blood vessel based on at least three first arrival times measured in correspondence, and at least three measured in correspondence with each of the at least three ultrasonic arrays. An inner diameter calculating unit that calculates an inner diameter of the blood vessel based on the second arrival time.

According to the present invention, since the transmission angle control unit that controls the transmission angle of the ultrasonic wave is provided so that the ultrasonic wave passes through the center of the blood vessel, the ultrasonic wave is reliably transmitted in a direction orthogonal to the wall surface of the blood vessel. Therefore, it is possible to prevent a decrease in the intensity of the reflected wave as in the prior art, and to receive the reflected wave reliably.
In addition, the first reflected wave measuring unit that measures the first arrival time of the first reflected wave that takes the shortest time to receive after the transmission of the ultrasonic wave, and the predetermined time set with reference to the first arrival time A second reflected wave measuring unit that measures the second arrival time of the second reflected wave that has reached the ultrasonic array within the range is provided. Here, the first reflected wave is an ultrasonic wave reflected by the outer wall of the blood vessel closest to the ultrasonic array. And, “the second reflected wave that has reached the ultrasonic array within a predetermined time range” means that after a time predicted to receive the reflected wave reflected on the inner wall of the blood vessel next to the first reflected wave, has elapsed. This is a reflected wave that reaches the ultrasonic array within a range up to a time predicted to receive a reflected wave reflected by the outer wall of the blood vessel farthest from the ultrasonic array.
According to this, for example, it is possible to exclude receiving a reflected wave reflected on the inner wall of the blood vessel next to the first reflected wave and a reflected wave reflected on the outer wall of the blood vessel farthest from the ultrasonic array. It is possible to reliably distinguish and receive the reflected wave and the second reflected wave that arrives after a predetermined time. Therefore, a desired reflection position in the ultrasonic blood vessel can be detected more accurately.
The outer diameter calculation unit can accurately calculate the outer diameter of the blood vessel based on the coordinates of at least three reflection positions detected from the first arrival time of the first reflected wave. The inner diameter calculation unit can accurately calculate the inner diameter of the blood vessel based on the coordinates of at least three reflection positions detected from the second arrival time of the second reflected wave.

  In the blood vessel diameter measuring device of the present invention, the control circuit changes the transmission angle by the transmission angle control unit corresponding to each of two of the at least three ultrasonic arrays. Among the plurality of ultrasonic waves transmitted from the ultrasonic array, obtain the transmission angle of the ultrasonic wave that is measured by the latest arrival reflected wave that is reflected by the blood vessel and reaches the ultrasonic array latest, and the 2 A central position estimating unit for estimating the central position of the blood vessel based on the transmission angle of the ultrasonic waves obtained by measuring the two latest arrival reflected waves obtained corresponding to each of the two ultrasonic arrays It is preferable.

  According to the present invention, the center position estimation unit detects ultrasonic waves when at least two latest arrival reflected waves at which the ultrasonic waves transmitted from the at least two ultrasonic arrays reach the ultrasonic array are measured at the latest. Since the central position of the blood vessel is estimated based on each transmission angle, the processing speed can be improved as compared with the case where the central position is estimated using three ultrasonic arrays.

  In the blood vessel diameter measuring device according to the present invention, the second reflected wave measuring unit determines whether or not there is at least one non-amplitude period of the reflected wave between the first reflected wave and the second reflected wave. It is preferable.

  According to the present invention, the second reflected wave measuring unit determines whether there is at least one non-amplitude period between the first reflected wave and the second reflected wave. A reflected wave that is continuous with two reflected waves can be detected. According to this, when the second reflected wave measuring unit detects that the reflected wave is continuous, the ultrasonic wave is transmitted and the reflected wave is measured until the non-amplitude period is detected. The reflection position of the first reflected wave and the reflection position of the second reflected wave can be clearly specified, and the diameter of the blood vessel can be accurately measured.

  In the blood vessel diameter measuring device according to the present invention, the outer diameter calculation unit may calculate the coordinates of the reflection positions in the blood vessel of the at least three first reflected waves calculated corresponding to each of the at least three ultrasonic arrays. The center coordinate of the blood vessel is calculated based on the coordinates, and the inner diameter calculation unit coordinates the reflection position in the blood vessel of the at least three second reflected waves calculated corresponding to each of the at least three ultrasonic arrays. And calculating the center coordinate of the blood vessel based on the difference between the center coordinate of the blood vessel calculated by the outer diameter calculation unit and the center coordinate of the blood vessel calculated by the inner diameter calculation unit. It is preferable to provide a warning output unit that determines whether or not the amount exceeds a predetermined threshold and outputs a warning when the amount exceeds the threshold.

By the way, if the blood vessel contracts or the probe is too close to the living body and the shape of the blood vessel is not circular, the center coordinates calculated by the outer diameter calculation unit and the center coordinates calculated by the inner diameter calculation unit May be different.
Therefore, according to the present invention, a warning output unit that compares the deviation amount of each center coordinate with a predetermined threshold value is provided, and this warning output unit outputs a warning when the deviation amount exceeds the threshold value. According to this, for example, after the user receives a warning, re-measurement after re-attaching the probe to the inspection target position, etc., until the deviation amount of each center coordinate becomes smaller than the threshold value, More accurate blood vessel center coordinates can be obtained, and the blood vessel diameter can be accurately measured.

  In the blood vessel diameter measuring device of the present invention, the control circuit changes the transmission angle by the transmission angle control unit corresponding to each of two of the at least three ultrasonic arrays. Among the plurality of ultrasonic waves transmitted from the ultrasonic array, obtain the transmission angle of the ultrasonic wave that is measured by the latest arrival reflected wave that is reflected by the blood vessel and reaches the ultrasonic array latest, and the 2 A center position estimating unit for estimating the center position of the blood vessel based on the transmission angle of the ultrasonic waves obtained by measuring the two latest arrival reflected waves obtained corresponding to each of the two ultrasonic arrays; A deviation amount between the center estimated position of the blood vessel estimated by the center position estimating unit, the center coordinates of the blood vessel calculated by the outer diameter calculating unit, and the center coordinates of the blood vessel calculated by the inner diameter calculating unit. Predetermined threshold Determines whether exceeds, when at least one of the displacement amount exceeds the threshold value, it is preferable and a warning output unit that outputs a warning.

  According to the present invention, the warning output unit compares a deviation amount between the estimated center position of the blood vessel and the center coordinates calculated by the outer diameter calculation unit and the inner diameter calculation unit, and the deviation amount exceeds the threshold value. If it is, a warning is output. In this case, as described above, by reattaching the probe and performing re-measurement, it is possible to obtain a more accurate blood vessel center coordinate and to accurately measure the blood vessel diameter.

The figure which shows the external appearance of the blood vessel diameter measuring apparatus of this embodiment which concerns on this invention. The top view which shows schematic structure of the probe of the said embodiment. The enlarged plan view which expanded the ultrasonic array of the said embodiment, and its sectional drawing. The figure which shows the transmission angle of the ultrasonic wave at the time of delaying the drive signal input into each ultrasonic element of the said embodiment by (DELTA) t in order, and inputting. The figure which shows the scan area of the ultrasonic array of the said embodiment. The block diagram which shows schematic structure of the blood vessel diameter measuring apparatus of the said embodiment. The figure which shows the reflected wave of the ultrasonic wave transmitted from the ultrasonic array of the said embodiment. The figure which shows typically the ultrasonic wave which passes along the center position of the blood vessel from each ultrasonic array of the said embodiment. The block diagram which shows schematic structure of the measurement control part of the said embodiment. The flowchart which shows the measurement process of the blood vessel diameter measuring apparatus of the said embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[1. Schematic configuration of blood vessel diameter measuring device]
FIG. 1 is a diagram showing an appearance of a blood vessel diameter measuring apparatus 1 according to this embodiment.
As shown in FIG. 1, the blood vessel diameter measuring device 1 includes a device main body 2 and a band 3 for attaching the device main body 2 to a living body such as a human body. The blood vessel diameter measuring device 1 is attached to the living body by tightening the band 3 in a state where the living body is in contact with the back surface of the apparatus main body 2, and measures the outer diameter and inner diameter of the blood vessel in the living body. .

[2. Configuration of main unit]
As shown in FIG. 1, the apparatus main body 2 includes a rectangular parallelepiped casing 21, and a sensor window 22 is formed on the back side of the apparatus main body 2. 23 is provided. In addition to the probe 23, the apparatus body 2 is provided with a control circuit 4 (see FIG. 6).
As described above, the probe 23 is in close contact with the living body when the blood vessel diameter measuring apparatus 1 measures the outer diameter and inner diameter of the blood vessel in the living body.
Further, although not shown in the drawings, an operation unit for operating the blood vessel diameter measuring device 1 and a display unit for displaying measurement results are provided on the surface side of the apparatus body 2.

[2-1. Probe Configuration]
FIG. 2 is a plan view showing a schematic configuration of the probe 23 of the present embodiment.
As shown in FIG. 2, the probe 23 includes a rectangular substrate 10 made of silicon (Si) or the like. Three ultrasonic arrays 11 (11A, 11B, and 11C) pass in the direction along the long side of the substrate 10 (the side on which the base end side of the band 3 is not attached) through the center position of the substrate 10. Is provided. The ultrasonic array 11 includes a plurality of ultrasonic elements 12 and has a linear array structure (one-dimensional array structure) in which the plurality of ultrasonic elements 12 are arranged in one direction along the scanning direction A. . When measuring the blood vessel diameter, the probe 23 is brought into close contact with the living body so that the arrangement direction of each ultrasonic element 12 is orthogonal to the axial direction of the blood vessel.

FIG. 3 is an enlarged plan view (FIG. 3A) and an enlarged sectional view (FIG. 3B) in which the ultrasonic array 11 is enlarged.
The ultrasonic element 12 constituting the ultrasonic array 11 includes a diaphragm 13 and a piezoelectric body 14 formed on the diaphragm 13. The configuration of the diaphragm 13 and the piezoelectric body 14 will be described later.
Here, a plurality of openings 101 having a circular shape in plan view are formed in the substrate 10 in a direction along the long side. In addition, a support film 15 is laminated on the substrate 10, and the opening 101 is closed by the support film 15.

The support film 15 is configured by a two-layer structure of, for example, a SiO ₂ film and a ZrO ₂ layer. Here, when the substrate 10 is a Si substrate, the SiO ₂ layer can be formed by thermally oxidizing the surface of the substrate. The ZrO ₂ layer is formed on the SiO ₂ layer by a technique such as sputtering.

  The diaphragm 13 is constituted by a region of the support film 15 that closes the opening 101. The diaphragm 13 is exposed from the opening 101 to the space in the ultrasonic output direction of the ultrasonic element 12 (the lower direction in FIG. 3B).

The piezoelectric body 14 includes a lower electrode 141 stacked on the upper layer of the support film 15, a piezoelectric film 142 formed on the lower electrode 141, and an upper electrode 143 formed on the piezoelectric film 142.
As shown in FIG. 3A, the lower electrode 141A is connected to the lower electrode 141A that extends along the direction orthogonal to the scanning direction A on the support film 15. The lower electrode line 141A is provided independently for each ultrasonic element 12.
An upper electrode line 143 </ b> A extending along the scanning direction A on the support film 15 is connected to the upper electrode 143. The upper electrode line 143A is a common electrode line in one ultrasonic array 11. That is, the upper electrode line 143A is connected to the upper electrode 143 of the adjacent ultrasonic element 12, as shown in FIG. 3, and is connected to, for example, GND at the end. As a result, the upper electrode 143 of each ultrasonic element 12 is grounded.

The piezoelectric film 142 is formed, for example, by forming PZT (lead zirconate titanate) into a film shape. In this embodiment, PZT is used as the piezoelectric film 142. However, any material can be used as long as it can be contracted in the in-plane direction by applying a voltage, for example, lead titanate. (PbTiO ₃ ), lead zirconate (PbZrO ₃ ), lead lanthanum titanate ((Pb, La) TiO ₃ ), or the like may be used.

In such an ultrasonic element 12, the piezoelectric film 142 expands and contracts in the in-plane direction by applying a voltage to the lower electrode 141 and the upper electrode 143. At this time, one surface of the piezoelectric film 142 is joined to the support film 15 via the lower electrode 141, but the upper electrode 143 is formed on the other surface, but the other surface is on the upper electrode 143. Therefore, the support film 15 side of the piezoelectric film 142 is not easily expanded and contracted, and the upper electrode 143 side is easily expanded and contracted. For this reason, when a voltage is applied to the piezoelectric film 142, a convex bend is generated on the opening 101 side, and the diaphragm 13 is bent. Therefore, when an AC voltage is applied to the piezoelectric film 142, the diaphragm 13 vibrates in the film thickness direction, and ultrasonic waves are transmitted by the vibration of the diaphragm 13.
When receiving ultrasonic waves with the ultrasonic element 12, when the ultrasonic waves are input to the diaphragm 13, the diaphragm 13 vibrates in the film thickness direction. In the ultrasonic element 12, the vibration of the diaphragm 13 causes a potential difference between the surface on the lower electrode 141 side and the surface on the upper electrode 143 side of the piezoelectric film 142, and the displacement of the piezoelectric film 142 from the upper electrode 143 and the lower electrode 141. A reception signal (current) corresponding to the amount is output.

FIG. 4 is a diagram illustrating the transmission direction (transmission angle) of ultrasonic waves when the drive signals input to the ultrasonic elements 12A to 12D are sequentially delayed by Δt and input.
In the ultrasonic array 11 in which a plurality of ultrasonic elements 12 are arranged along the scanning direction A in the present embodiment, the timing of transmitting ultrasonic waves from each ultrasonic element 12 is delayed and shifted so that the ultrasonic elements 12 are superposed in a desired direction. It becomes possible to transmit a plane wave of a sound wave.
When an ultrasonic wave is transmitted from each ultrasonic element 12, a synthetic wavefront W in which these ultrasonic waves strengthen each other is formed and propagated. Here, as shown in FIG. 4, when the drive signal input to each of the ultrasonic elements 12A to 12D whose arrangement interval is set to d is delayed by Δt, the ultrasonic element to which the drive signal has been input first is delayed. Since the phase of the wavefront of the ultrasonic wave transmitted from 12 and the wavefront transmitted from the ultrasonic element 12 to which the drive signal is input later are different, the composite wavefront W is propagated with an inclination with respect to the scanning direction A. The

  At this time, if the transmission angle between the propagation direction of the combined wavefront W and the direction orthogonal to the scanning direction A is θs and the sound speed is c, the relationship of the following equation (1) is established.

FIG. 5 is a diagram showing a scan area Sarea of one ultrasonic array 11.
As described above, the ultrasonic array 11 can change the transmission angle of the ultrasonic wave by delaying the timing of the drive signal input to each ultrasonic element 12. Here, since the ultrasonic array 11 has a linear array structure (one-dimensional array structure), the transmission angle of the ultrasonic wave passes through the scanning direction A as shown in FIG. Therefore, the transmission angle cannot be changed in a direction intersecting with the scan plane S. As a result, the scan area Sarea of the ultrasonic array 11 is formed in the scan plane S that passes through the scanning direction A and is orthogonal to the substrate 10. If the probe 23 is in close contact with the living body so that the blood vessel passes through the scan area Sarea, the ultrasonic wave is transmitted from the ultrasonic array 11 to the scan area Sarea and the ultrasonic wave reflected by the blood vessel is received. This makes it possible to detect the intersection between the blood vessel and the scan area Sarea.

[2-2. Configuration of control circuit]
FIG. 6 is a block diagram showing a schematic configuration of the blood vessel diameter measuring apparatus 1 of the present embodiment.
The control circuit 4 includes an ultrasonic array switching circuit 41, a transmission / reception switching circuit 42, an ultrasonic mode switching control unit 43, an ultrasonic signal transmission circuit 44, a signal delay circuit 45 (transmission angle control unit), and reception. A measurement unit 46 (first reflected wave measurement unit, second reflected wave measurement unit), a delay time calculation unit 47, a storage unit 48, and a measurement control unit 49 are provided.

The ultrasonic array switching circuit 41 is a switching circuit that switches the ultrasonic array 11 to be driven among the three ultrasonic arrays 11 provided in the probe 23.
In the blood vessel diameter measuring apparatus 1 of the present embodiment, while ultrasonic waves are being transmitted / received from one ultrasonic array 11, output of drive signals to other ultrasonic arrays 11 and other ultrasonic arrays 11 are performed. The reception signal from is not received. As a result, the ultrasonic array 11 to be driven receives the ultrasonic waves transmitted from the other ultrasonic arrays 11, and the inconvenience of detecting noise or reception from the ultrasonic array 11 other than the drive target. The inconvenience that a signal is detected can be avoided.
The ultrasonic array switching circuit 41 includes, for example, a terminal group connected to the lower electrode line 141A and the upper electrode line 143A of each ultrasonic array 11, and switches to select an array input from the measurement control unit 49. Based on the control signal, the terminal group corresponding to the ultrasonic array 11 based on the switching control signal and the transmission / reception switching circuit 42 are connected. The terminal group corresponding to the ultrasonic array 11 that is not driven may be configured not to be driven by connecting both the lower electrode line 141A and the upper electrode line 143A to GND, for example.

The transmission / reception switching circuit 42 is a switching circuit that switches a connection state based on a mode switching signal input from the ultrasonic mode switching control unit 43.
Specifically, when a control signal for switching to the ultrasonic transmission mode is input from the ultrasonic mode switching control unit 43, the reception / transmission switching circuit 42 converts the drive signal input from the signal delay circuit 45 into the ultrasonic wave. The connection is switched to a connection state that can be output to the array switching circuit 41. On the other hand, the reception / transmission switching circuit 42 receives the reception signal input from the ultrasonic array switching circuit 41 when the control signal for switching to the ultrasonic reception mode is input from the ultrasonic mode switching control unit 43. Switch to a connection state that can output.

The ultrasonic mode switching control unit 43 switches between an ultrasonic transmission mode in which ultrasonic waves are transmitted from the ultrasonic array 11 and an ultrasonic reception mode in which ultrasonic waves are received by the ultrasonic array 11.
Specifically, when a control signal for starting measurement of the diameter of the blood vessel is input from the measurement control unit 49, the ultrasonic mode switching control unit 43 first performs processing for switching to the ultrasonic wave transmission mode. In this process, the ultrasonic mode switching control unit 43 outputs a control signal for switching to the transmission mode to the transmission / reception switching circuit 42 and outputs a control signal for outputting a drive signal from the ultrasonic signal transmission circuit 44. To do.
The ultrasonic mode switching control unit 43 recognizes the time measured by a timer (not shown) and performs a process of switching from the ultrasonic transmission mode to the ultrasonic reception mode after a predetermined transmission time has elapsed. Here, the transmission time should just be set to about the time when the burst wave of 1-2 frequency is transmitted from the ultrasonic array 11, for example. In the reception mode, the ultrasonic mode switching control unit 43 outputs a control signal for switching to the reception / transmission switching circuit 42 to the reception mode, and the reception / transmission switching circuit 42 receives the reception signal input from the ultrasonic array 11. The reception measuring unit 46 is switched to a connectable state.
The ultrasonic mode switching control unit 43 performs the above process, for example, a preset number of times. This number of times is appropriately set according to the set number of ultrasonic transmission angles.For example, as shown in FIG. 5, when the ultrasonic transmission angle is switched to five stages to estimate the center position of the blood vessel, Repeat the above process 5 times.

  In the transmission mode, the ultrasonic signal transmission circuit 44 is driven to drive the ultrasonic elements 12 of the ultrasonic array 11 when a control signal for outputting a drive signal is input from the ultrasonic mode switching control unit 43. A signal (drive voltage) is output to the signal delay circuit 45.

When a drive signal for each ultrasonic element 12 is input from the ultrasonic signal transmission circuit 44 from the ultrasonic signal transmission circuit 44, the signal delay circuit 45 delays the drive signal and outputs it to the transmission / reception switching circuit 42.
Here, the signal delay circuit 45 receives the delayed drive signal obtained by delaying the drive signal for driving each ultrasonic element 12 by Δt based on the delay setting signal input from the delay time calculation unit 47. Output to the transmission switching circuit 42.

FIG. 7 is a diagram showing reflected waves of ultrasonic waves transmitted from the ultrasonic array 11.
FIG. 8 is a diagram schematically showing ultrasonic waves passing from the respective ultrasonic arrays 11 through the central position of the blood vessel.
The reception measuring unit 46 monitors the time measured by the time measuring unit and measures the time until the ultrasonic wave is received.
Specifically, the reception measurement unit 46 resets the timing at which the ultrasonic mode switching control unit 43 performs the process of switching to the transmission mode, that is, the time counted by the time measuring unit by the ultrasonic mode switching control unit 43 is reset. Monitor the time from. The reception measurement unit 46 performs a process in which the ultrasonic mode switching control unit 43 switches to the reception mode, and a reception signal corresponding to the reflected ultrasonic wave received by the ultrasonic array 11 is received and measured from the transmission / reception switching circuit 42. When input to the unit 46, the time at the input timing (TOF data: Time Of Flight data) is acquired, and the TOF data is input to the measurement control unit 49.

The reception measurement unit 46 finishes inputting the last of the reception signals of the reflected waves transmitted from the two ultrasonic arrays 11 at each transmission angle (for example, transmission angles θ1 to θ5 shown in FIG. 5) and reflected by the blood vessel. Two TOF data of the received signal is acquired. The reception signal for which the input to the reception measurement unit 46 is finished last is a reception signal of the reflected wave at the reflection position farthest from the ultrasonic array 11.
Further, as shown in FIG. 7, the reception measurement unit 46 receives a reception signal of the first reflected wave of the ultrasonic wave transmitted at the transmission angle in the received signal (the first reflected wave according to the present invention). Time point t1 (first arrival time according to the present invention) and time point t3 (second arrival time according to the present invention) when the received signal of the third reflected wave (second reflected wave according to the present invention) is input. The TOF data is acquired. In addition, the TOF data of the first wave and the third wave of the reflected wave of the ultrasonic wave transmitted based on the transmission angle θs from the remaining ultrasonic array 11 calculated by the center position estimation unit 491 described later is acquired. .

Here, the reception measuring unit 46 has patterns of waveform 1 to waveform 4 shown in FIG. In FIG. 7, for convenience of illustration, the blood vessel is shown in a circular shape.
For example, in the waveform 1, the reflected wave on the inner wall and the outer wall of the blood vessel can be ideally obtained, whereas in the waveform 2, the third wave is caused by the deformation of the blood vessel into an elliptical shape or the like due to contraction or the like. The wave and the fourth wave are continuous reflected waves. In the waveform 3, the first wave and the second wave are continuous, and the third wave and the fourth wave are continuous reflected waves due to the extremely thin portion of the blood vessel. The waveform 4 is a reflected wave in which the first wave to the fourth wave are continuous because the blood vessel is contracted considerably compared to the case of the waveform 2 and the waveform 3 and the thick part of the blood vessel is extremely thin. ing.
Therefore, it is necessary for the reception measurement unit 46 to receive the third-wave reception signal separately from the second-wave and fourth-wave reception signals, particularly in the waveform 1 and waveform 2 patterns. Therefore, if the time t3 when the received signal of the third reflected wave is input satisfies the condition within the range of the predetermined time T in the following equation (2), the received signals of the second and fourth waves are Only the third wave reception signal can be received without reception.

Here, R is the outer diameter of the blood vessel, and c is the speed of sound. L is the thickness dimension of the blood vessel, and it is obtained by L = (R−r) / 2 where r is the inner diameter of the blood vessel. Generally, since the inner diameter r is 1 (mm) and the outer diameter R is 3 (mm), the wall thickness L is 1 (mm). Since the speed of sound c is 1530 (m / s), if these are substituted into the above equation (2), 1300 (ns) <
The relationship of T <3920 (ns) is established.

The reception measurement unit 46 detects whether or not there is one non-amplitude period from the reception of the first wave reception signal shown in FIG. 7 to the reception of the third wave reception signal. That is, the reception measurement unit 46 detects the presence or absence of an unamplitude period between the reception of the first wave reception signal and the reception of the third wave reception signal, and if there is at least one unamplitude period Judge that there is no influence of noise. On the other hand, if there is no unamplitude period, the reception measurement unit 46 determines that there is an influence of noise or the like, inputs a remeasurement signal to the measurement control unit 49, and receives an ultrasonic mode switching control unit from the measurement control unit 49. The control signal is input to 43.
For example, in the waveform 1 pattern of FIG. 7, after receiving the first wave reception signal, the second wave passes through the non-amplitude period, the third wave passes through the non-amplitude period, and the fourth wave passes through the non-amplitude period. Therefore, there are three non-amplitude periods. In the waveform 2 pattern of FIG. 7, since the second wave is received through the non-amplitude period after receiving the first wave reception signal, and the third wave reception signal is received through the non-amplitude period. There are two periods. In the pattern of the waveform 3 in FIG. 7, since the received signal of the third wave is received through the non-amplitude period after receiving the received signal of the first wave, there is one unamplified period. However, in the pattern of the waveform 4 in FIG. 7, since the reflected wave is continuous after the reception signal of the first wave is received and the reception signal is continuously received, there is no non-amplitude period, and the influence of noise. It is judged that there is.

The delay time calculation unit 47 calculates the drive delay time of each ultrasonic element 12 based on the transmission angle data input from the measurement control unit 49.
Here, the transmission angle data is data stored in advance in the storage unit 48. For example, in the present embodiment, as shown in FIG. 5, five transmission angle data of θs = θ1 to θ5 are stored in advance. The structure which is made is illustrated. Note that six or more transmission angle data may be stored, and the transmission angle may be changed more finely.
Then, the delay time calculation unit 47 uses the input transmission angle data θs, the preset element pitch d of the ultrasonic element 12, and the sound velocity c based on the above equation (1). Time Δt is calculated and output to the signal delay circuit 45 as a delay setting signal.

The storage unit 48 includes a recording medium such as a memory or a hard disk, and stores various data and programs necessary for processing in the reception measurement unit 46, the delay time calculation unit 47, and the measurement control unit 49 so that they can be read out appropriately. To do.
Specifically, examples of the various data include position data of the ultrasonic array 11 in the probe 23, transmission angle data θs, and TOF data. As various programs, which will be described in detail later, a center position estimation program that is executed by the measurement control unit 49 and estimates the center position of the blood vessel based on the TOF data, and six points of the blood vessel reflection position based on the TOF data. Reflection position coordinate calculation program for calculating the coordinate position of the blood vessel, outer diameter calculation program for calculating the outer diameter of the blood vessel and the central coordinates of the blood vessel from the three coordinate positions of the reflection position, and the inner diameter of the blood vessel from the three coordinate positions of the reflection position And an inner diameter calculation program for calculating the center coordinates of the blood vessel, a warning output program for comparing the center coordinates of the two blood vessels, and informing a warning.

FIG. 9 is a block diagram illustrating a schematic configuration of the measurement control unit 49.
The measurement control unit 49 includes, for example, a CPU (Central Processing Unit) and the like, and executes a program stored in the storage unit 48. That is, the measurement control unit 49 realizes various functions by processing the program and data stored in the storage unit 48. Such a measurement control unit 49, when measuring the diameter of the blood vessel, processes the program to obtain a center position estimation unit 491, a reflection position coordinate calculation unit 492, an outer diameter, as shown in FIG. The calculation unit 493, the inner diameter calculation unit 494, and the warning output unit 495 are realized as functions.

The center position estimation unit 491 transmits the transmission angle data based on the two TOF data of the reflected wave at the reflection position farthest from the ultrasonic array 11 and the two TOF data of the reflected wave at the closest reflection position. With reference to θs, the center position of the blood vessel is estimated, and this is set as the center estimated position.
Then, the center position estimation unit 491 calculates a transmission angle θs so as to transmit ultrasonic waves from the remaining ultrasonic arrays 11 other than the already driven two ultrasonic arrays 11 to the center estimated position, The transmission angle data θs is input to the delay time calculation unit 47.

  The reflection position coordinate calculation unit 492 generates six reflection positions (A1, A2, B1, B2, C1, C2 in FIG. 8) from the ultrasonic array 11 based on the input first-wave and third-wave TOF data. ) Is calculated. Based on the transmission angle data stored in the storage unit 48, the position of the ultrasonic array 11B is set as the origin, the arrangement interval of the ultrasonic array 11 is set as P, and the coordinate positions of the six points are expressed by the following equation (3). It calculates using-(8).

  The outer diameter calculation unit 493 calculates the outer diameter R of the blood vessel using the following equation (9) based on the coordinate positions of A1, B1, and C1 among the six reflection positions, and the center coordinate O ( x, y) is calculated.

  The inner diameter calculation unit 494 calculates the inner diameter r of the blood vessel using the following equation (10) based on the coordinate positions of A2, B2, and C2 among the six reflection positions, and the center coordinates O (x, y) is calculated.

The warning output unit 495 compares the deviation amount of the two center coordinates calculated by the outer diameter calculation unit 493 and the inner diameter calculation unit 494 with a predetermined threshold value. The warning output unit 495 notifies the user of a warning to the effect that the probe 23 is to be attached again to the inspection target position on the display unit (not shown) of the apparatus main body 2 when the deviation amount exceeds the threshold value.
Further, the warning output unit 495 compares the amount of deviation between the two center coordinates calculated by the outer diameter calculation unit 493 and the inner diameter calculation unit 494 and the estimated center position of the blood vessel estimated by the center position estimation unit 491. When the deviation amount exceeds the threshold value, a warning to the user that the probe 23 is to be reattached to the inspection target position is notified to a display unit (not shown) of the apparatus main body 2.

[3. Measurement process of blood vessel diameter measuring device]
Next, the measurement process of the blood vessel diameter measuring apparatus 1 will be described with reference to the flowchart shown in FIG.
First, the probe 23 of the blood vessel diameter measuring apparatus 1 is brought into close contact with a test target position such as an arm of a living body, and the apparatus body 2 is fixed to the test target position by tightening the band.
Then, when an input signal is input by the user operating an operation unit (not shown), the blood vessel diameter measuring device 1 starts measuring the diameter of the blood vessel.

  Next, the measurement control unit 49 performs processing for switching the two ultrasonic arrays 11 to be drivable. Here, the measurement control unit 49 outputs a switching control signal for switching the two ultrasonic arrays 11 to be drivable to the ultrasonic array switching circuit 41.

And the measurement control part 49 implements the various processes in ultrasonic transmission mode (step S1).
In this ultrasonic transmission mode, the measurement control unit 49 reads the transmission angle data θs from the storage unit 48 and outputs it to the delay time calculation unit 47. Here, first, the transmission angle data θ <b> 1 is read and output to the delay time calculation unit 47. Thereby, the delay time calculation unit 47 calculates the delay time Δt based on the equation (1), and outputs it to the signal delay circuit 45 as a delay setting signal.

In addition, when the measurement control unit 49 inputs a control signal for switching to the ultrasonic transmission mode from the measurement control unit 49 to the ultrasonic mode switching control unit 43, the ultrasonic signal transmission circuit 44 causes the two ultrasonic arrays 11. A drive signal (drive pulse) to be output to each ultrasonic element 12 is output to the signal delay circuit 45. In the signal delay circuit 45, the delay setting signal is input from the delay time calculation unit 47 as described above. Therefore, each drive signal is output to the transmission / reception switching circuit 42 after being delayed by a delay time based on the delay setting signal.
The transmission / reception switching circuit 42 outputs the drive signal input from the signal delay circuit 45 to the ultrasonic array switching circuit 41.

In addition, the transmission / reception switching circuit 42 outputs the drive signal input from the signal delay circuit 45 to the ultrasonic array switching circuit 41 in accordance with the control signal input from the ultrasonic mode switching control unit 43 as described above. Has been switched to. Therefore, the delayed drive signal output from the signal delay circuit 45 is output to the ultrasonic elements 12 of the two ultrasonic arrays 11 via the ultrasonic array switching circuit 41.
As described above, ultrasonic waves are output from the two ultrasonic arrays 11 at a transmission angle corresponding to the transmission angle data θ1. By performing the above processing for the transmission angle data θ2 to θ5, ultrasonic waves are output from the two ultrasonic arrays 11 at transmission angles corresponding to the transmission angle data θ1 to θ5.

  In addition, the reception measurement unit 46 performs a process in which the ultrasonic mode switching control unit 43 switches to the reception mode, and a reception signal corresponding to the reflected ultrasonic wave received by the ultrasonic array 11 is received and measured from the transmission / reception switching circuit 42. When input to the unit 46, the time at the input timing is acquired. Then, the ultrasonic mode switching control unit 43 performs various processes in the ultrasonic reception mode, for example, after a time during which burst waves having one or two cycles are output (step S2).

In the ultrasonic reception mode in step S2, the ultrasonic mode switching control unit 43 outputs a control signal indicating that the reception signal input from the ultrasonic array switching circuit 41 is output to the reception / transmission switching circuit 42 to the reception measurement unit 46. To do.
As a result, when an ultrasonic wave is received by the ultrasonic array 11 and a reception signal is input from the ultrasonic array switching circuit 41 to the transmission / reception switching circuit 42, this reception signal is output to the reception measurement unit 46.
The reception measurement unit 46 monitors the time counted by the time measurement unit, acquires TOF data that is the time from the timing at which the ultrasonic wave is transmitted to the timing at which the reception signal is input, and outputs the TOF data to the measurement control unit 49. To do. And the measurement control part 49 memorize | stores the input TOF data in the memory | storage part 48 so that reading is possible suitably.
As described above, the TOF data stored in the storage unit 48 is transmitted from the two ultrasonic arrays 11 at each transmission angle (for example, transmission angles θ1 to θ5 shown in FIG. 5) and reflected by the blood vessel. Among the received signals of the reflected wave, there are two TOF data of the received signal that has been input last, and two TOF data of the received signal of the reflected wave that is reflected earliest.

Next, the center position estimation unit 491 of the measurement control unit 49 reads the TOF data and the like from the storage unit 48, estimates the center position of the blood vessel, and sets this as the center estimated position (step S3). Then, the center position estimation unit 491 calculates a transmission angle θs so as to transmit ultrasonic waves from the remaining ultrasonic arrays 11 other than the already driven two ultrasonic arrays 11 to the center estimated position, The transmission angle data θs is input to the delay time calculation unit 47.
Thereafter, the remaining ultrasonic array 11 transmits ultrasonic waves at the calculated transmission angle θs, and the reception measurement unit 46 acquires the first and third wave TOF data of the reflected waves of the ultrasonic waves. And input to the measurement control unit 49. And the measurement control part 49 memorize | stores the input TOF data in the memory | storage part 48 so that reading is possible suitably.

The reception measurement unit 46 detects whether or not there is a non-amplitude period between the reception of the first wave and the reception of the third wave among the reflected waves (step S4). If there is at least one unamplified period, it is determined that there is no influence of noise or the like, and the process of the next step S5 is executed.
On the other hand, if there is no non-amplitude period (such as when receiving a received signal), the reception measurement unit 46 determines that there is an influence of noise or the like, returns to step S1, and the measurement control unit 49 Various processes in the sound wave transmission mode are performed. If it is determined that there is no non-amplitude period even if the processes from step S1 to step S4 are performed a predetermined number of times, the measurement control unit 49 performs a process of outputting an error indicating that the probe 23 is reattached to the user.

Next, the reflection position coordinate calculation unit 492 of the measurement control unit 49 performs a process of calculating the coordinate position of the reflection position (step S5).
The reflection position coordinate calculation unit 492 reads the TOF data and the like from the storage unit 48, and determines the coordinate positions of the six reflection positions A1, A2, B1, B2, C1, and C2 shown in FIG. 8).

Then, the outer diameter calculation unit 493 uses the coordinate positions of the reflection positions A1, B1, C1 calculated in step S5 and the above equation (9), and the outer diameter R of the blood vessel and the central coordinate O (x, y) is calculated (step S6).
Furthermore, the inner diameter calculation unit 494 uses the coordinate positions of the reflection positions A2, B2, and C2 calculated in step S5 and the above equation (10), and the inner diameter r of the blood vessel and the central coordinate O (x, y) of the blood vessel. Is calculated (step S7).

Next, the warning output unit 495 compares the shift amount of each central coordinate O calculated in steps S6 and S7 with a predetermined threshold (step S8). If the deviation amount of each central coordinate O is larger than a predetermined threshold, the user is notified of a warning that the probe 23 is to be reattached to the inspection target position (step S9), and the process returns to step S1 and remeasured. To start.
On the other hand, when the deviation amount of each center coordinate O is smaller than a predetermined threshold value, the deviation amount between each center coordinate O and the estimated center position is compared with a predetermined threshold value (step S10). When the deviation amount is smaller than the threshold value, the blood vessel diameter measurement process is terminated. However, when the deviation amount is larger than the threshold value, the warning output unit 495 notifies the warning in step S9, returns to step S1, and starts remeasurement.

[4. Effects of this embodiment]
In this embodiment, since the signal delay circuit 45 that controls the transmission angle of the ultrasonic wave is provided so that the ultrasonic wave passes through the central coordinate O of the blood vessel, the ultrasonic wave is reliably transmitted in a direction orthogonal to the wall surface of the blood vessel. It is possible to transmit, prevent a decrease in the intensity of the reflected wave as in the conventional case, and receive the reflected wave reliably.
In addition, a reception measurement unit 46 that measures a reflected wave that has arrived within a predetermined time T of the above formula (2) as a third wave from the first wave that takes the shortest time to receive after transmitting the ultrasonic wave. Is provided. In other words, by providing the reception measurement unit 46, the second wave and the fourth wave reflected by the inner wall of the blood vessel next to the first wave can be excluded, and the first wave and the signal received within the predetermined time T range. It becomes possible to distinguish and receive the third wave. According to this, the TOF data of the received signal of the third wave can be obtained accurately, and the coordinates of the reflection positions A2, B2, and C2 on the ultrasonic blood vessel are expressed by the above equations (4), (6), and (8). It can be obtained accurately by using. Accordingly, the outer diameter calculation unit 493 and the inner diameter calculation unit 494 can calculate the outer diameter R, the inner diameter r, and the center coordinate O of the blood vessel more accurately using the above formulas (9) and (10).

Further, since the reception measurement unit 46 determines whether there is at least one non-amplitude period from the first wave to the third wave, for example, the first wave to the third wave are continuous. A reflected wave can be detected. Therefore, when the reflected wave is a continuous wave, the reflection position of the first wave and the reflection position of the third wave can be reliably identified by re-measurement, and the accurate diameter of the blood vessel can be determined. You can make measurements.
In addition, a warning output unit 495 that compares the deviation amount of each central coordinate O calculated by the outer diameter calculation unit 493 and the inner diameter calculation unit 494 with a predetermined threshold is provided, and the warning output unit 495 has a deviation amount exceeding the threshold. If it is, a warning that the probe 23 is to be reattached is output. According to this, after the user reattaches the probe 23 to the inspection target position, the measurement is performed again, and the deviation amount of each central coordinate O becomes smaller than the threshold value, so that the more accurate central coordinate O of the blood vessel can be obtained. Therefore, the blood vessel diameter can be accurately measured.
Further, the warning output unit 495 compares the deviation amount between the center estimated position of the blood vessel estimated by the center position estimating unit 491 and the center coordinates O calculated by the outer diameter calculating unit 493 and the inner diameter calculating unit 494, If the amount exceeds the threshold, a warning that the probe 23 will be reattached is output. By re-measuring, a more accurate blood vessel center coordinate can be obtained, and an accurate blood vessel diameter can be measured.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the embodiment, the center position of the blood vessel is estimated based on the two reflected waves of the ultrasonic waves transmitted from the two ultrasonic arrays 11, but the ultrasonic waves transmitted from the three ultrasonic arrays 11. The center position of the blood vessel may be estimated based on the three reflected waves. In this case, the accuracy of estimating the center position can be further improved as compared with the case where the center position of the blood vessel is estimated using the two ultrasonic arrays 11.

In the embodiment, the blood vessel diameter measuring apparatus 1 using the three ultrasonic arrays 11 is exemplified, but the present invention is not limited to this, and four or more ultrasonic arrays 11 may be used.
In the above embodiment, the opening 101 has a circular shape in plan view. However, the opening 101 is not limited to this. For example, the opening 101 has a rectangular shape according to the deflection balance of the diaphragm 13 or the vibration stability of the diaphragm 13 by the piezoelectric body 14. It may be formed in other shapes. That is, the shape of the ultrasonic element 12 can be freely designed in consideration of the stress balance during vibration of the diaphragm 13.

  In the embodiment, each ultrasonic array 11 performs both transmission and reception of ultrasonic waves by each ultrasonic element 12, and the ultrasonic mode switching control unit 43 controls the ultrasonic transmission mode, the ultrasonic reception mode, and so on. However, the present invention is not limited to this, and a configuration may be employed in which an ultrasonic element dedicated to reception and an ultrasonic element dedicated to transmission are arranged in parallel.

In the embodiment, an example in which the delay time calculation unit 47 is a device that calculates the delay time of the drive signal input to each ultrasonic element 12 by receiving the transmission angle data from the measurement control unit 49, that is, the delay time. Although the calculation part 47 showed the example comprised as hardware, it is not limited to this. For example, the delay time calculation program may be stored in the storage unit 48, and the delay time calculation program may be read and executed by the measurement control unit 49, so that the delay time is calculated for each drive signal.
In the embodiment, the measurement control unit 49 reads and executes various programs as the center position estimation unit 491, the reflection position coordinate calculation unit 492, the outer diameter calculation unit 493, the inner diameter calculation unit 494, and the warning output unit 495. For example, the center position estimation unit 491, the reflection position coordinate calculation unit 492, the outer diameter calculation unit 493, the inner diameter calculation unit 494, and the warning output unit 495 are formed by an integrated circuit such as an IC, for example. It may be configured as hardware.

  DESCRIPTION OF SYMBOLS 1 ... Blood vessel diameter measuring apparatus, 4 ... Control circuit, 11 ... Ultrasonic array, 12 ... Ultrasonic element, 23 ... Probe, 45 ... Signal delay circuit (transmission angle control part), 46 ... Reception measurement part (1st reflected wave) Measurement unit, second reflected wave measurement unit), 491 ... center position estimation unit, 493 ... outer diameter calculation unit, 494 ... inner diameter calculation unit, 495 ... warning output unit.

The present invention relates to a blood vessel diameter measuring apparatus that measures the diameter of a blood vessel in a living body using ultrasonic waves , and a blood vessel diameter measuring method .

An object of the present invention is to provide a blood vessel diameter measuring apparatus and a blood vessel diameter measuring method capable of measuring an accurate blood vessel diameter.

The blood vessel diameter measuring apparatus of the present invention includes an ultrasonic array provided on a probe that can contact a living body,
A control circuit that calculates an outer diameter and an inner diameter of the blood vessel based on an arrival time from when the ultrasonic wave is transmitted from the ultrasonic array to the blood vessel in the living body to reach the ultrasonic array. wherein the ultrasound array comprises an arrangement has been linear array structure a plurality of ultrasonic elements along the scan direction line on a substrate, wherein the control circuit is perpendicular to the scanning direction line as said substrate in the scan plane of said at least three ultrasound control to said at least three different three angles outgoing angle with respect to the scanning direction line of the ultrasonic wave to pass through the center of the blood vessel to be transmitted from the ultrasonic array outgoing angle and a control unit, wherein each originating on at least three ultrasonic waves are reflected by the blood vessel, the earliest the first arrival time of the first reflected wave reaches the ultrasonic array to Measured, before Symbol reception measurement unit for measuring a second reflected wave second arrival time of which has reached the ultrasound array within a predetermined time set the first arrival time as a reference, said at least three super an outer diameter calculation unit that calculates the outer diameter of the blood vessel based on at least three of said first arrival time is measured corresponding to each sound wave was measured corresponding to each of said at least three ultrasound An inner diameter calculating unit that calculates an inner diameter of the blood vessel based on at least three second arrival times.

According to the present invention, since the transmission angle control unit that controls the transmission angle of the ultrasonic wave is provided so that the ultrasonic wave passes through the center of the blood vessel, the ultrasonic wave is reliably transmitted in a direction orthogonal to the wall surface of the blood vessel. Therefore, it is possible to prevent a decrease in the intensity of the reflected wave as in the prior art, and to receive the reflected wave reliably.
Further, the first arrival time of the first reflected wave that takes the shortest time until the reception after the transmission of the ultrasonic wave is measured , and the ultrasonic wave is further within a predetermined time range set based on the first arrival time. A reception measurement unit that measures the second arrival time of the second reflected wave that has reached the array is provided. Here, the first reflected wave is an ultrasonic wave reflected by the outer wall of the blood vessel closest to the ultrasonic array. And, “the second reflected wave that has reached the ultrasonic array within a predetermined time range” means that after a time predicted to receive the reflected wave reflected on the inner wall of the blood vessel next to the first reflected wave, has elapsed. This is a reflected wave that reaches the ultrasonic array within a range up to a time predicted to receive a reflected wave reflected by the outer wall of the blood vessel farthest from the ultrasonic array.
According to this, for example, it is possible to exclude receiving a reflected wave reflected on the inner wall of the blood vessel next to the first reflected wave and a reflected wave reflected on the outer wall of the blood vessel farthest from the ultrasonic array. It is possible to reliably distinguish and receive the reflected wave and the second reflected wave that arrives after a predetermined time. Therefore, a desired reflection position in the ultrasonic blood vessel can be detected more accurately.
The outer diameter calculation unit can accurately calculate the outer diameter of the blood vessel based on the coordinates of at least three reflection positions detected from the first arrival time of the first reflected wave. The inner diameter calculation unit can accurately calculate the inner diameter of the blood vessel based on the coordinates of at least three reflection positions detected from the second arrival time of the second reflected wave.

In the blood vessel diameter measuring device of the present invention, the control circuit includes a plurality of ultrasonic waves transmitted from the ultrasonic array at a plurality of transmission angles set in advance by the transmission angle control unit on the scan surface . to give the outgoing angle of the ultrasonic wave slowest arriving reflected wave is measured to reach a slowest the ultrasound array is reflected by the blood vessel, before Symbol slowest arriving reflected wave the calling of the ultrasonic wave is measured It is preferable to include a center position estimation unit that estimates the center position of the blood vessel based on the angle.

According to the present invention, the center position estimation unit, among the plurality of ultrasonic wave transmitted by the plurality of outgoing angle set in advance, most late arrival reflected wave it reaches the slowest ultrasonic array is measured ultrasonic based on the outgoing angles of the sound waves to estimate the center position of the blood vessel. Thereby , processing speed can be improved compared with the case where the center position is estimated using all the ultrasonic arrays.

In the blood vessel diameter measuring device of the present invention, it is preferable that the reception measurement unit determines whether or not there is at least one non-amplitude period of the reflected wave from the first reflected wave to the second reflected wave. .

According to the present invention, since the reception measurement unit determines whether there is at least one non-amplitude period between the first reflected wave and the second reflected wave, for example, the first reflected wave and the second reflected wave. It is possible to detect a reflected wave that is continuous. According to this, when the reception measurement unit detects that the reflected wave is continuous, the ultrasonic wave is transmitted and the reflected wave is measured until the non-amplitude period is detected. The reflection position of the second reflection wave and the reflection position of the second reflected wave can be clearly specified, and the diameter of the blood vessel can be accurately measured.

In the blood vessel diameter measuring apparatus according to the present invention, the outer diameter calculation unit is based on the coordinates of the reflection positions of the at least three first reflected waves calculated corresponding to the at least three ultrasonic waves in the blood vessel. The center coordinate of the blood vessel is calculated, and the inner diameter calculation unit is based on the coordinates of the reflection positions in the blood vessel of the at least three second reflected waves calculated corresponding to each of the at least three ultrasonic waves. The control circuit calculates the center coordinate of the blood vessel, and the control circuit determines a deviation amount between the center coordinate of the blood vessel calculated by the outer diameter calculation unit and the center coordinate of the blood vessel calculated by the inner diameter calculation unit. It is preferable to provide a warning output unit that determines whether or not a predetermined threshold is exceeded and outputs a warning when the threshold is exceeded.

In the blood vessel diameter measuring device of the present invention, the control circuit includes a plurality of ultrasonic waves transmitted from the ultrasonic array at a plurality of transmission angles set in advance by the transmission angle control unit on the scan surface . to give the outgoing angle of the ultrasonic wave slowest arriving reflected wave is measured to reach a slowest the ultrasound array is reflected by the blood vessel, before Symbol slowest arriving reflected wave the calling of the ultrasonic wave is measured Based on the angle, a center position estimating unit that estimates the center position of the blood vessel, the center estimated position of the blood vessel estimated by the center position estimating unit, and the center coordinates of the blood vessel calculated by the outer diameter calculating unit And whether or not the deviation amount from the central coordinates of the blood vessel calculated by the inner diameter calculation unit exceeds a predetermined threshold value, and if at least one deviation amount exceeds the threshold value, a warning is issued. Warning output to be output It is preferably provided and.
According to the present invention, the warning output unit compares a deviation amount between the estimated center position of the blood vessel and the center coordinates calculated by the outer diameter calculation unit and the inner diameter calculation unit, and the deviation amount exceeds the threshold value. If it is, a warning is output. In this case, as described above, by reattaching the probe and performing re-measurement, it is possible to obtain a more accurate blood vessel center coordinate and to accurately measure the blood vessel diameter.

The blood vessel diameter measurement method of the present invention has an ultrasonic array provided on a probe that can contact a living body, and a line array structure in which a plurality of ultrasonic elements are arranged on a substrate along a straight line in the scanning direction. An ultrasonic array is provided, and a method of measuring a blood vessel diameter of a blood vessel in the living body using a probe that can come into contact with the living body, wherein the ultrasound is passed through the scanning direction straight line and orthogonal to the substrate. The transmission angles of the at least three ultrasonic waves with respect to the scanning direction straight line are controlled at three different angles so that at least three ultrasonic waves transmitted from the sound wave array pass through the center of the blood vessel, and the at least three super waves are controlled. A first arrival time of a first reflected wave that is transmitted by a sound wave, is reflected by the blood vessel for each of the transmitted at least three ultrasonic waves, and reaches the ultrasonic array earliest; A second arrival time of the second reflected wave that has reached the ultrasonic array within a predetermined time range set with respect to the first arrival time, and corresponds to each of the at least three ultrasonic waves. The outer diameter of the blood vessel is calculated based on the at least three first arrival times measured in the above, and based on the at least three second arrival times measured corresponding to each of the at least three ultrasonic waves. The inner diameter of the blood vessel is calculated.
In the present invention, similar to the above-described invention, for example, the reception of the reflected wave reflected on the inner wall of the blood vessel after the first reflected wave and the reflected wave reflected on the outer wall of the blood vessel farthest from the ultrasonic array is excluded. Thus, the first reflected wave and the second reflected wave that arrives after a predetermined time can be reliably distinguished and received. Therefore, a desired reflection position in the ultrasonic blood vessel can be detected more accurately. Thereby, the outer diameter of the blood vessel based on the reflection position coordinates detected from the first arrival time and the inner diameter of the blood vessel based on the reflection position coordinates detected from the second arrival time can be accurately calculated.
Further, in the blood vessel diameter measuring method of the present invention, a plurality of ultrasonic waves are transmitted from the ultrasonic array at a plurality of transmission angles set in advance by the transmission angle control unit within the scan plane, and transmitted. Among the plurality of ultrasonic waves, the transmission angle of the ultrasonic wave from which the latest reflected wave that is reflected at the blood vessel and reaches the ultrasonic array latest is measured, and the latest reflected wave is measured. It is preferable to estimate the center position of the blood vessel based on the transmission angle of the ultrasonic wave.
Thereby, the center position of the blood vessel can be estimated quickly as in the above-described invention.

Claims (5)

At least three ultrasonic arrays provided on a probe in contact with a living body;
A control circuit that calculates an outer diameter and an inner diameter of the blood vessel based on an arrival time from when the ultrasonic wave is transmitted from the ultrasonic array to the blood vessel in the living body to reach the ultrasonic array. Prepared,
The ultrasonic array has a line array structure in which a plurality of ultrasonic elements are arranged in one direction along a scanning direction,
The control circuit includes:
Corresponding to each of the at least three ultrasound arrays,
The ultrasonic waves are transmitted so that the ultrasonic waves transmitted from the ultrasonic array pass through the center of the blood vessel by sequentially delaying the timing at which the ultrasonic elements transmit ultrasonic waves with respect to the scanning direction. A transmission angle control unit for controlling a transmission angle with respect to the scanning direction;
A first reflected wave measuring unit that measures the first arrival time of the first reflected wave that is transmitted from the blood vessel and is first reflected by the blood vessel and reaches the ultrasonic array;
A second reflected wave measurement unit that measures a second arrival time of the second reflected wave that has reached the ultrasonic array within a predetermined time range set with respect to the first arrival time; and
An outer diameter calculator that calculates an outer diameter of the blood vessel based on at least three first arrival times measured corresponding to each of the at least three ultrasonic arrays;
A blood vessel diameter measuring apparatus comprising: an inner diameter calculating unit that calculates an inner diameter of the blood vessel based on at least three second arrival times measured corresponding to each of the at least three ultrasonic arrays. . In the blood vessel diameter measuring device according to claim 1,
The control circuit includes:
Corresponding to each of two of the at least three ultrasound arrays,
Among the plurality of ultrasonic waves transmitted from the ultrasonic array by changing the transmission angle by the transmission angle control unit, the latest arrival reflected wave that is reflected by the blood vessel and reaches the ultrasonic array latest is measured. Obtain the transmission angle of the ultrasonic wave,
A center position estimation unit that estimates the center position of the blood vessel based on the transmission angle of the ultrasonic waves obtained by measuring the two latest arrival reflected waves obtained corresponding to each of the two ultrasonic arrays A blood vessel diameter measuring apparatus comprising: In the blood vessel diameter measuring apparatus according to claim 1 or 2,
The second reflected wave measuring unit determines whether or not there is at least one non-amplitude period of a reflected wave between the first reflected wave and the second reflected wave. . In the blood vessel diameter measuring device according to any one of claims 1 to 3,
The outer diameter calculation unit calculates the central coordinates of the blood vessel based on the coordinates of the reflection positions of the at least three first reflected waves calculated for each of the at least three ultrasonic arrays in the blood vessel. And
The inner diameter calculation unit calculates the central coordinates of the blood vessel based on the coordinates of the reflection positions of the at least three second reflected waves in the blood vessel calculated corresponding to each of the at least three ultrasonic arrays. ,
The control circuit determines whether a deviation amount between the blood vessel center coordinates calculated by the outer diameter calculation unit and the blood vessel center coordinates calculated by the inner diameter calculation unit exceeds a predetermined threshold value. A blood vessel diameter measuring apparatus comprising: a warning output unit that determines and outputs a warning when the threshold value is exceeded. In the blood vessel diameter measuring device according to claim 4,
The control circuit includes:
Corresponding to each of two of the at least three ultrasound arrays,
Among the plurality of ultrasonic waves transmitted from the ultrasonic array by changing the transmission angle by the transmission angle control unit, the latest arrival reflected wave that is reflected by the blood vessel and reaches the ultrasonic array latest is measured. Obtain the transmission angle of the ultrasonic wave,
A center position estimation unit that estimates the center position of the blood vessel based on the transmission angle of the ultrasonic waves obtained by measuring the two latest arrival reflected waves obtained corresponding to each of the two ultrasonic arrays When,
A deviation amount between the center estimated position of the blood vessel estimated by the center position estimating unit, the center coordinates of the blood vessel calculated by the outer diameter calculating unit, and the center coordinates of the blood vessel calculated by the inner diameter calculating unit. A blood vessel diameter measuring apparatus comprising: a warning output unit that determines whether or not a predetermined threshold value is exceeded and outputs a warning when at least one deviation amount exceeds the threshold value.