JP2005028123A - Method and apparatus for measuring blood vessel diameter using echo - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more easy and sure method and apparatus for measuring a blood vessel diameter, by which effect of variation of a blood vessel diameter by cardiac beat can be avoided by a simple construction to reduce a load on the subject by ischemia, to more stably and surely fix an echo probe on a measurement location, and to set a direction of an ultrasonic emitting face. <P>SOLUTION: Upon imaging an echo image of the upper arm artery of an examinee to measure a diameter of the upper arm artery based on the echo image, an echo image along a plane substantially orthogonally crossing the center line of the upper arm artery is imaged. The blood essel center on the echo image of the upper arm artery displayed on an x-y coordinates is calculated. Polar coordinate conversion is carried out making the blood vessel center the origin. A blood vessel edge is detected based on the echo image of the polar coordinate. An average diameter of the upper arm artery is calculated based on the detected data of the edge. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blood vessel diameter measuring method and apparatus using an echo, more specifically, a blood vessel diameter measurement in which an echo image of a predetermined blood vessel of a measurement subject is taken and the diameter of the blood vessel is measured based on the echo image. The present invention relates to a method and an apparatus for measuring such a blood vessel diameter.

Conventionally, as a method for noninvasively measuring and evaluating the suppleness of blood vessels, a method for measuring vascular wall hardness, vascular volume change, and the like, which are mechanical physical quantities of blood vessels, is known. It is widely used for diagnosis.
The former is based on the phenomenon that the speed at which the pulse wave propagates through the arterial tube becomes faster as the vessel wall becomes harder. The The latter is based on an event in which the blood vessel volume varies nonlinearly due to blood pressure fluctuation of the pulse wave, and an index obtained from an empirical rule is used as a parameter representing the amount of change in the blood vessel volume.

  However, each of these conventional methods basically observes the normal pulsation state of a blood vessel as it is, and a change related to the mechanical physical quantity of the blood vessel actually occurs in the living body, which is significant in physical quantity. It often takes a significant amount of time (eg, months or longer) before it can be perceived as a significant change, so it can only be detected after vascular arteriosclerosis has progressed significantly physically. There are many cases where this is not possible.

  By the way, in recent years, in the process of studying the mechanism of arteriosclerosis, it has been found that endothelial dysfunction of blood vessels is involved in arteriosclerosis in the early stage of arteriosclerosis. In other words, nitric oxide (NO), a physiologically active substance released from vascular endothelial cells, expands smooth muscle and suppresses arteriosclerosis such as suppression of platelet condensation and suppression of adhesion of blood monocytes to the endothelium. Has become an important indicator. And it was discovered that there is a correlation between the failure of the release function of nitric oxide and the occurrence of arteriosclerosis.

As described above, nitric oxide released from the endothelial cells of blood vessels has an action of expanding smooth muscle. Therefore, in order to evaluate the failure of the release function for releasing nitric oxide from the endothelial cells of blood vessels (hereinafter referred to as “endothelial dysfunction” of blood vessels as appropriate), the degree of dilation of the blood vessels should be measured. become.
Therefore, as a method for measuring blood vessel endothelial dysfunction in a non-invasive manner in a short time, a method for forcibly relaxing a blood vessel and measuring it has been considered. This method can be performed, for example, by the following procedure (a series of steps).

[A] First, the subject is kept calm for a predetermined period (for example, 15 minutes).
[B] After the rest period, the subject's heart rate is measured with an electrocardiograph, and the longitudinal direction of the ultrasound emitting part is the center line of the subject's brachial artery (hereinafter referred to as “long axis” as appropriate). An ultrasonic linear probe with a predetermined frequency (for example, 7.5 to 15 MHz) is set so as to coincide with a plane including, and an echo image is pulsated by synchronizing the end diastole of the blood vessel with the R wave of the heartbeat. Acquire for the period. By synchronizing with the heartbeat R wave in this way, an echo image that is not affected by fluctuations in the blood vessel diameter due to pulsation can be obtained. In this case, an echo image of the surface including the center line of the blood vessel (hereinafter referred to as “long-axis echo image” as appropriate) is obtained.
[C] The brachial artery diameter at rest is measured from this echo image, and an average value for a plurality of pulsation periods is obtained.

[D] Next, a cuff is wound around the forearm and held at a predetermined pressure (for example, 250-300 mmHg) for a predetermined time (for example, 5 minutes) to block the artery.
[E] After this ischemic period, the cuff pressure is released and the blood flow is rapidly released.
[F] In the hyperemic reaction process associated with the rapid release of blood flow, an echo image is acquired by the same method as in step [b] after a predetermined time (for example, 1 minute) has elapsed since the release. When the cuff pressure is released, the brachial artery gradually expands the blood vessel diameter in about 1 minute during the hyperemia phase, and takes a maximum value after about 45-60 seconds. The maximum blood vessel diameter can be measured.
[G] The blood vessel diameter (brachial artery diameter) after the hyperemic reaction is measured from this echo image, and an average value for a plurality of pulsation periods is obtained.

[H] Then, an increment and an increase rate of the average value (blood vessel diameter after hyperemia reaction) obtained in step [g] with respect to the average value (blood vessel diameter at rest) obtained in step [c] are calculated. The percentage of increase is displayed as a change amount of the blood vessel diameter as a percentage (%: percent).
This value is the so-called% FMD (Flow-Mediated Dilatation), and it can be used effectively in the diagnosis of blood vessel endothelial dysfunction, that is, the diagnosis of arteriosclerosis, etc. Can do.

The blood flow-dependent vasodilator response (FMD) measurement method described above utilizes the fact that the hyperemia reaction for compensating for the metabolic abnormality caused by ischemia in the living body will maximize the expansion of the blood vessel. As a method for non-invasively measuring the dysfunction of endothelial cells in a relatively simple and short time, it is becoming popular.
The conventional diagnostic methods for observing changes related to the mechanical physical quantity of blood vessels do not show arteriosclerosis, and even a seemingly healthy person is already in the early stages of arteriosclerosis progression if diagnosed from the viewpoint of endothelial dysfunction. It may be included.

As is clear from the above explanation,% FMD represents the degree of vascular endothelial function failure and is an index that sensitively reflects the increased adhesion of blood monocytes to the endothelium and the enhancement of platelet condensation. Early arteriosclerosis may also be suggested. That is, it is an important index for detecting arteriosclerosis at an extremely early stage and suppressing its progression.
In addition, by using the above-described% FMD, the influence of blood viscosity (slack / smoothness) over a certain period of time can be expressed as a degree of vascular roughness / smoothness. Therefore, it is possible to use this% FMD as a new index indicating the flexibility of blood vessels.

Furthermore,% FMD, as a basic principle, evaluates the failure of the function of releasing nitric oxide from vascular endothelial cells, and the kinetics of nitric oxide is indirectly observed. It is possible to determine the effect in a shorter period (for example, several hours or several days).
Therefore, its application range is wide, and it can be applied not only to the diagnosis of arteriosclerosis but also to a wide range of fields such as diets such as antioxidant supplements and health foods, or determination of drug effects such as hyperlipidemia and diabetes. ing.

  However, when measuring% FMD, the echo probe must be brought into contact with the subject's brachial artery along the long axis and perpendicular to the skin surface and measured after a 15-minute rest period (see above steps). There is a problem that it is difficult to make the contact portion of the echo probe coincide with each other in the measurement after the ischemia for 5 minutes (see step [f] described above). In addition, it has been demanded that the ischemic work by the cuff and the measurement of the blood vessel diameter from the echo image can be performed more simply and accurately.

In response to such problems, one of the applicants of the present application described in Patent Document 1 is to fix the echo probe to the upper arm of the subject with a magic band, and to perform ischemic work using a pump for intake and exhaust of the ischemic cuff. Proposed to automate, and further to transfer echo images to a personal computer and apply an image processing technique to measure blood vessel diameter.
JP 2003-180690 A

However, in the prior art proposed in the above-mentioned Patent Document 1, there are still various matters to be improved as described below.
That is, firstly, as described in the above step [b], the blood vessel diameter is measured only by taking an echo image on the long axis side of the blood vessel, that is, the longitudinal direction of the ultrasonic wave emitting unit is the blood vessel. Since the ultrasonic linear probe is set so as to match the surface including the center line and the echo image of the surface including the center line of the blood vessel is captured, the inspector is required to have a high degree of skill, and the inspection staff There was a problem that it was limited to use in abundant research facilities and large hospitals.

In the blood flow-dependent vasodilator response (FMD) measurement method described above, the vasodilator response caused by about 5 minutes of ischemia of the brachial artery and the subsequent hyperemia reaction is about 10% in terms of rate of change. When applied to a numerical value of diameter (generally about 4 mm), it is known that it is only a small value of about 0.4 mm.
Therefore, when measuring the blood vessel diameter by the FMD method, an echo image of the blood vessel diameter is obtained for an appropriate length substantially corresponding to the length of the echo probe by capturing an echo image of the long axis side of the blood vessel with the echo probe. By averaging the values of the blood vessel diameter calculated based on these echo images, the blood vessel diameter can be obtained with relatively high accuracy even when the rate of change due to the vasodilation reaction is small as described above. It is.

However, in order to obtain a clear echo image along the long axis of the blood vessel, it is necessary to search for a position where the echo signal matches the diameter of the blood vessel. In order to set the echo probe so that it passes along the diameter position of the blood vessel, considerable skill is required.
The direction of blood vessel travel and the depth from the skin surface vary to some extent depending on the subject's physique, etc., so a lot of experience is required to properly set the echo probe as described above. There is an aspect that must be relied on.
In particular, in the blood vessel hyperemia reaction process, it is necessary to complete the measurement within about 15 seconds of about 45-60 seconds after releasing the cuff pressure (see the above step [f]), so that the quick measurement work is accurate. In this respect, the inspector is required to have a high level of skill.

  Furthermore, in order to accurately measure the blood vessel diameter, it is important how to accurately recognize the blood vessel wall from the echo image obtained by imaging, but in the echo image obtained by the echo probe, Various noises are included due to the influence of multiple reflection and the like, and depending on the position of the blood vessel wall, there is a possibility that the blood vessel wall is likely to be misidentified in relation to the emission direction of the echo.

  Next, as a second problem, in the prior art proposed in Patent Document 1 above, in order to avoid the influence of the fluctuation of the blood vessel diameter due to pulsation, the measurement of the heart rate by the electrocardiograph is the measurement of the blood vessel diameter. Since it is necessary to carry out in parallel and synchronize between the two (see step [b] described above), the inspector is required to have a higher level of skill, and an expensive echo device is required. There was a problem that the measuring device would be large.

It is known that the expansion and contraction in the radial direction of the brachial artery due to pulsation generally reaches several percent of the blood vessel diameter, and% FMD is a measured value depending on at which timing of the pulsation the echo image acquired is used. Makes a big difference.
Therefore, conventionally, an electrocardiograph is used in combination with an end-diastolic stage of the subject's blood vessel by blood flow-dependent vasodilator response (FMD), and in the electrocardiogram, the blood vessel diameter is measured using only an echo image synchronized with the heartbeat R wave. By doing this, the influence of the fluctuation of the blood vessel diameter due to the heartbeat was eliminated as much as possible.

  However, in this case, since the electrocardiograph is used together, the apparatus has to be large, and an expensive echo device having a function of acquiring and storing an echo image in synchronization with the electrocardiograph is necessary. It becomes. When using an echo device that does not have such a function, for example, a device that synchronizes an echo image signal and an electrocardiograph signal is prepared separately as seen in a system of MIA (Medical Imaging Applications). After all, the entire apparatus must be expensive and large.

Further, as a third problem, in the conventional FMD measurement, the forearm portion is pressurized to 250-300 mmHg with a cuff to block the brachial artery of a subject (a person to be measured) (step [d] described above) reference). This set value of cuff pressure has been used as a value that can reliably block blood flow in the brachial artery, but the level of cuff pressure that can be used to block blood is determined for each individual subject. For example, it should be different depending on the blood pressure.
However, conventionally, since the blood is blocked for a long period of about 5 minutes with the uniformly high cuff pressure as described above, the subject is considerably painful and burdensome.

  Furthermore, there are some problems with the adhesion and fixing method of the echo probe to the upper arm of the subject. For example, a linear probe that has been conventionally used as an echo probe has a flat ultrasonic emission surface, so that it is difficult to sufficiently adhere to the surface shape of the arm in measurements during the resting period and the hyperemia period. There is a problem that it is actually difficult to maintain the set orientation stably and properly. In addition, regarding the method of fixing the echo probe to the upper arm of the subject, in order to obtain a more stable echo image in the measurement in the resting period and the hyperemic period across a long ischemic period of about 5 minutes, It is necessary to fix the echo probe more stably and reliably to the surface of the surface.

  The present invention has been made in view of the above technical problem, and enables measurement work to be performed more easily and accurately when measuring the diameter of a blood vessel, and the fluctuation of the blood vessel diameter due to heartbeat with a relatively simple configuration. In addition, the burden on the subject due to ischemia can be reduced, and furthermore, the echo probe can be fixed to the measurement site and the proper orientation of the ultrasonic emission surface can be set more stably and reliably. The basic purpose is to

  For this reason, the blood vessel diameter measuring method according to the first invention of the present application is the blood vessel diameter measuring method of taking an echo image of a predetermined blood vessel of the measurement subject and measuring the diameter of the blood vessel based on the echo image. An echo image is taken along a plane substantially perpendicular to the center line of the blood vessel.

  In this case, specifically, with respect to the obtained echo image, the blood vessel center on the echo image of the predetermined blood vessel displayed in the xy coordinate system is obtained and converted into a polar coordinate system with the blood vessel center as the origin. It is preferable to display the echo image, detect an edge of the blood vessel based on the echo image displayed in polar coordinates, and obtain an average diameter of the blood vessel based on detection data of the edge.

  In performing the coordinate conversion to the polar coordinate system, the blood vessel wall surface portion that is most proximal to the echo emission side is set to 0 degrees, and the blood vessel wall surface portion that is substantially farthest from the echo emission side is 180 degrees. It is preferable to perform coordinate conversion as degrees.

  Also, the polar coordinate display echo image obtained by the above coordinate conversion is subjected to high frequency noise removal processing using a moving average filter, and based on the luminance information of the image data of the echo image subjected to this high frequency noise removal processing. More preferably, a position where the deviation in luminance is larger than a predetermined value is recognized as a blood vessel edge, and a position where the deviation in position is larger than a certain value is excluded as a false recognition position for the blood vessel edge on the entire blood vessel wall surface.

  Further, the echo image of the polar coordinate display is inversely transformed into the xy coordinate system, and the echo image obtained by the inverse transformation is compared with the echo image of the original xy coordinate display. It is more preferable to correct the blood vessel edge detection data based on the above.

  When obtaining the blood vessel center on the echo image, a circular template substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system is prepared. A circular template may be approximately overlapped with the edge of the blood vessel, and the center of the overlapped circular template may be assumed as the blood vessel center.

  In addition, a circular template having a variable diameter substantially corresponding to the blood vessel edge on the echo image displayed in the xy coordinate system is prepared, and the template is the blood vessel edge on the echo image. The diameter of the blood vessel can be obtained by adjusting the diameter of the template so as to approximately overlap with the diameter of the blood vessel.

  In the above case, when estimating the maximum dilated vessel diameter, the vascular diameter is gradually increased based on the measured values of the dilated vessel diameters in the process of hyperemia and the measured value of the reference vessel diameter at rest. May be estimated by a linear regression method, and the estimated value of the expanded blood vessel diameter corresponding to the hyperemia reaction time of 60 seconds may be set as the maximum expanded blood vessel diameter.

  Furthermore, in the above case, at least one of the diastolic phase and the systolic phase of the blood vessel can be automatically detected based on the position information of the blood vessel edge obtained from the luminance information of the image data of the echo image.

  The blood vessel diameter measuring method according to the second invention of the present application is the blood vessel diameter measuring method in which an echo image of a predetermined blood vessel of a measurement subject is taken and the diameter of the blood vessel is measured based on the echo image. When the image is captured, image data of a predetermined number of frames immediately after the echo image is frozen is stored, and at least one of the diastolic phase and the systolic phase of the blood vessel is detected based on the image data of the predetermined number of frames It is characterized by that.

  In this case, specifically, a template having a size approximate to the diameter of the blood vessel on the echo image is prepared, and the image data of the predetermined number of frames is relatively compared with the template as a reference. It is possible to detect at least one of the diastole and the systole of the blood vessel.

Furthermore, in this case, it is preferable to automatically detect at least one of the diastolic phase and the systolic phase of the blood vessel based on the luminance information of each image data of the predetermined number of frames.
In the above case, it is more preferable that the predetermined number of frames corresponds to a time longer than the heartbeat cycle of the measurement subject.

  Furthermore, in the above case, the cuff pressure is applied to the first part of the arm of the measurement subject and the blood is blocked for a predetermined time, and then the cuff pressure is released, and a predetermined timing before the cuff pressure is applied and after the cuff pressure is released. Thus, it is possible to take an echo image of a predetermined blood vessel flowing through the second part in the arm portion of the measurement subject and measure the diameter of the blood vessel based on the echo image.

  The blood vessel diameter measuring method according to the third invention of the present application is the method of releasing cuff pressure after applying cuff pressure to the first part in the arm of the measurement subject and blocking the blood for a predetermined time, before applying the cuff pressure, In a blood vessel diameter measuring method for capturing an echo image of a predetermined blood vessel flowing through the second part in the arm portion of the measurement subject at a predetermined timing after pressure release, and measuring the diameter of the blood vessel based on the echo image, The ischemic cuff pressure is set based on the highest blood pressure of the measurement subject.

  The blood vessel diameter measuring method according to the fourth invention of the present application is a method in which the cuff pressure is applied to the first part in the arm portion of the measurement subject and is blocked for a predetermined time, then the cuff pressure is released, and before the cuff pressure is applied. In a blood vessel diameter measuring method for capturing an echo image of a predetermined blood vessel flowing through the second part in the arm portion of the measurement subject at a predetermined timing after pressure release, and measuring the diameter of the blood vessel based on the echo image, The blood pressure of the measurement subject is measured during the pressure control of the cuff pressure.

In these cases, it is possible to detect the subject's pulse pressure while increasing the cuff pressure, detect the cuff pressure when the pulse pressure disappears, and set the ischemic cuff pressure based on the detected value. it can.
In the above case, the first part may be the forearm and the second part may be the upper arm.

An apparatus for measuring a blood vessel diameter according to a fifth invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measurement subject, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. The blood vessel of the subject to be measured is set in such a manner that the echo probe of the imaging means and the echo probe of the imaging means are set so that the longitudinal direction of the ultrasonic wave emitting section is substantially perpendicular to the center line of the blood vessel. And a fixing means for fixing to a flowing portion.
In this specification, the “part where the blood vessel flows” of the measurement subject refers to the “part where the blood vessel is located (exists)” in the body of the measurement subject.

  In this case, specifically, display means for displaying the echo image obtained by the imaging means on the screen, and echo image of the predetermined blood vessel displayed in the xy coordinate system are represented by xy coordinates. Coordinate conversion display means capable of performing coordinate conversion display on a polar coordinate system with the blood vessel center on the displayed echo image as the origin, and the calculation means is configured to detect the blood vessel detected based on the polar coordinate display echo image. The average diameter of the blood vessel can be calculated based on the edge detection data.

  Further, in this case, a luminance deviation is predetermined based on the moving average filter that performs high-frequency noise removal processing on the echo image displayed in polar coordinates and the luminance information of the image data of the echo image that has been subjected to high-frequency noise removal processing. Edge recognition means for recognizing a position larger than the value as a blood vessel edge, and misrecognized position exclusion means for removing a position having a position deviation larger than a certain value as a false recognition position for the blood vessel edge of the entire blood vessel wall surface. Is preferred.

  Further, it is preferable that the coordinate conversion display means can reversely convert the echo image of the polar coordinate display into an xy coordinate system.

  In the above case, a circular template displaying a circle substantially corresponding to a blood vessel edge on the echo image displayed in the xy coordinate system and the center of the circle, and the circular template on the echo image It is more preferable to further include moving means for moving.

  A circular template displaying a circle substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system and the center of the circle, and a diameter variable means for changing the diameter of the circular template; A moving means for moving the circular template on the echo image may be further provided.

  An apparatus for measuring a blood vessel diameter according to a sixth invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measured person, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. And an image data storage unit that stores image data of a predetermined number of frames immediately after the echo image is frozen when the echo image is captured.

  In this case, it further comprises display means for displaying the echo image obtained by the imaging means on a screen, and a template having a size approximate to the diameter of the blood vessel on the echo image displayed on the display means. Is preferred.

In this case, it is more preferable to further include detection means for automatically detecting at least one of the diastolic phase and the systolic phase of the blood vessel based on the luminance information of each image data of the predetermined number of frames.
Further, in the above case, it is even more preferable that the predetermined number of frames corresponds to a time longer than the heartbeat cycle of the measurement subject.

  In the above-described case, the cuff pressure is applied to the first part in the arm portion of the measurement subject, and the cuff pressure is released after the cuff pressure is applied to the first part for a predetermined time. The cuff pressure control means for controlling the cuff pressure, the fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured, and the cuff pressure before applying the cuff pressure to the first part You may make it provide the imaging control means which controls the said imaging means so that the echo image of the predetermined blood vessel which flows through the said 2nd site | part may be imaged at the predetermined timing after release.

  An apparatus for measuring a blood vessel diameter according to a seventh invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measured person, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. Calculation means, an ischemic means that can apply a cuff pressure to the first part of the arm of the subject, and the cuff pressure is applied to the first part, and then the cuff pressure is released after the cuff pressure is applied for a predetermined time. The cuff pressure control means for controlling the cuff pressure, the fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured, and the cuff pressure before and after applying the cuff pressure to the first part. Imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing after the pressure is released, and the ischemic cuff pressure based on the maximum blood pressure of the subject. Set the ischemic cuff pressurization It is obtained by comprising: the means.

  An apparatus for measuring a blood vessel diameter according to an eighth aspect of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measured person, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. Calculation means, an ischemic means that can apply a cuff pressure to the first part of the arm of the subject, and the cuff pressure is applied to the first part, and then the cuff pressure is released after the cuff pressure is applied for a predetermined time. The cuff pressure control means for controlling the cuff pressure, the fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured, and the cuff pressure before and after applying the cuff pressure to the first part. An imaging control means for controlling the imaging means so as to take an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing after the pressure is released; and the blood pressure of the subject during the control of the cuff pressure Blood pressure measuring means for measuring In which it was characterized in that it was e.

  In these cases, pulse pressure detecting means for detecting the pulse pressure of the measurement subject when the cuff pressure increases is further provided, and the ischemic cuff is based on the cuff pressure at the time when the pulse pressure disappears. It is preferable to set the pressure.

An apparatus for measuring a blood vessel diameter according to a ninth invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measured person, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. Calculation means, an ischemic means that can apply a cuff pressure to the first part of the arm of the subject, and the cuff pressure is applied to the first part, and then the cuff pressure is released after the cuff pressure is applied for a predetermined time. The cuff pressure control means for controlling the cuff pressure, the fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured, and the cuff pressure before and after applying the cuff pressure to the first part. Imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing after the pressure is released, and the calculation means before the cuff pressure is applied After echo image and cuff pressure release Based on the echo image, the degree of expansion of the blood vessel diameter by the blood flow-dependent vasodilation reaction is calculated, and the calculation means is connected to the calculation means for displaying the degree of expansion of the blood vessel diameter in time series. It is characterized by that.
In the above case, the first part may be the forearm and the second part may be the upper arm.

An apparatus for measuring a blood vessel diameter according to a tenth invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measurement subject, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. Calculation means, fixing means for fixing the echo probe of the imaging means to the site where the blood vessel of the measurement subject flows, and adjusting the fixing state of the echo probe with respect to the flow direction of the blood vessel and the circumferential direction of the blood vessel And adjusting means that can be used.
In the present specification, the “direction in which the blood vessel flows” refers to the “direction in which blood in the blood vessel flows”, in other words, the direction along the center line of the blood vessel.

  An apparatus for measuring a blood vessel diameter according to an eleventh invention of the present application is an imaging unit that captures an echo image of a predetermined blood vessel of a measurement subject, and calculates the diameter of the blood vessel based on the echo image obtained by the imaging unit. Calculation means, fixing means for fixing the echo probe of the imaging means to the site where the blood vessel of the measurement subject flows, between the surface of the location of the measurement subject and the ultrasonic emission surface of the echo probe And a water bag interposed therebetween.

  According to the blood vessel diameter measurement method using the echo according to the first invention of the present application, an echo image (echo image on the short axis side) is taken along a surface substantially orthogonal to the center line of the blood vessel. Even if a slight error occurs in the direction setting (set) of the ultrasonic wave emitting portion of the echo probe, the obtained echo image always includes the diameter portion of the blood vessel. Therefore, unlike the conventional case where an echo image of the surface including the center line of the blood vessel (the echo image on the long axis side) has been imaged, a high level of skill is not required for the echo probe set (orientation setting). The blood vessel diameter can be easily measured.

  In this case, it is preferable that the echo image of the blood vessel displayed in the xy coordinate system is converted into a polar coordinate system with the blood vessel center on the image as the origin to display the normal (xy). In the case of a coordinate system, a substantially circular blood vessel edge can be displayed in a substantially straight line, and the blood vessel edge can be detected and the diameter of the blood vessel can be measured more easily and accurately. If the origin at the time of polar coordinate conversion deviates to some extent from the actual center of the blood vessel, or if the blood vessel edge on the echo image is distorted or deformed, it will appear as a linear distortion or deformation in the polar coordinate display However, by obtaining the average diameter of the blood vessel based on the blood vessel edge detection data detected on the echo image displayed in the polar coordinate display, distortion and deformation of the straight line are canceled out, so that a more accurate blood vessel diameter is easier. Can be requested.

  In performing the coordinate conversion to the polar coordinate system, the blood vessel wall surface portion that is most proximal to the echo emission side is set to 0 degrees, and the blood vessel wall surface portion that is substantially farthest from the echo emission side is 180 degrees. By performing coordinate conversion as a degree, the region of the blood vessel wall surface where the reflected echo is relatively easily obtained and the blood vessel edge can be detected relatively clearly (substantially the most proximal and distal to the echo emission side) Region) and regions that are relatively difficult to obtain reflected echoes and are prone to erroneous detection of blood vessel edges (both end regions in the direction orthogonal to the echo emission direction) can be easily recognized in advance in polar coordinate display to detect blood vessel edges. When performing, it can contribute to the improvement of the precision.

  Also, the polar coordinate display echo image obtained by the above coordinate conversion is subjected to high frequency noise removal processing using a moving average filter, and based on the luminance information of the image data of the echo image subjected to this high frequency noise removal processing. By recognizing the position where the luminance deviation is larger than the predetermined value as the blood vessel edge, the detection accuracy of the blood vessel edge can be further improved, and the position deviation of the blood vessel edge of the entire blood vessel wall surface is more than a certain value. By excluding a large position as a misidentification position, the blood vessel edge detection accuracy can be further enhanced.

  Further, the blood vessel edge is converted based on the result of inversely transforming the echo image of the polar coordinate display into the xy coordinate system and comparing the echo image obtained by the inverse transform with the echo image of the original xy coordinate display. By correcting the detected data, a more accurate blood vessel diameter can be obtained.

  In the above case, more preferably, a circular template substantially corresponding to the blood vessel edge on the echo image displayed in the xy coordinate system is used, and this circular template is used as the blood vessel edge on the echo image. The origin can be set more easily when polar coordinate conversion is performed by approximately overlapping and virtualizing the center of the circular template as the blood vessel center.

  Further, the diameter of a circular template substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system is variable, and the template is approximately overlapped with the edge of the blood vessel on the echo image. By adjusting the diameter of the template, the diameter of the blood vessel can be obtained more easily.

  In the above case, when estimating the maximum dilated vessel diameter, the vascular diameter is gradually increased based on the measured values of the dilated vessel diameters in the process of hyperemia and the measured value of the reference vessel diameter at rest. Is estimated by the linear regression method, and the estimated value of the expanded blood vessel diameter corresponding to the hyperemia reaction time of 60 seconds is set as the maximum expanded blood vessel diameter, whereby the maximum expanded blood vessel diameter can be estimated in a shorter time.

  Furthermore, in the above case, the blood vessel is automatically detected based on the position information of the blood vessel edge obtained from the luminance information of the image data of the echo image, thereby automatically detecting at least one of the diastolic phase and the systolic phase of the blood vessel. The diastolic phase and systolic phase can be detected more quickly, and the detection work can be saved.

  According to the blood vessel diameter measurement method using an echo according to the second invention of the present application, image data of a predetermined number of frames immediately after the echo image is frozen at the time of echo image capturing is stored, and the image data of the predetermined number of frames is stored. Based on the above, since at least one of the diastolic phase and systolic phase of the blood vessel is detected, there is no need to separately measure and synchronize the heartbeat of the person to be measured with an electrocardiograph. A diastole or a systole of a blood vessel can be detected without requiring a special device. In addition, since synchronous measurement with an electrocardiograph is unnecessary, a high level of skill is not required for measurement work.

  In this case, preferably, each of the predetermined number of frames of image data is relatively compared with a template having a size approximating the diameter of the blood vessel on the echo image as a reference, so that the diastolic and systolic phases of the blood vessel are compared. By detecting at least one of them, the diastole or systole of the blood vessel can be detected more easily.

  More preferably, the blood vessel diastole or systole is more quickly detected by automatically detecting at least one of the diastole and systole based on the luminance information of each image data of the predetermined number of frames. It can be detected, and the detection work can be saved.

  In the above case, more preferably, the predetermined number of frames corresponds to a time equal to or longer than the heartbeat cycle of the person being measured, so that the diastolic period of the blood vessel corresponding to at least one cycle of the heartbeat of the person being measured. In addition, the systole can be detected, and when measuring the maximum diameter or the minimum diameter of the blood vessel, the heart rate measurement of the measurement subject by the electrocardiograph can be made unnecessary.

  In all of the above cases, the cuff pressure is applied to the first part in the arm of the measurement subject and is blocked for a predetermined time, and then the cuff pressure is released. At a predetermined timing before the cuff pressure is applied and after the cuff pressure is released. Then, an echo image of a predetermined blood vessel flowing through the second part in the arm portion of the measurement subject is captured, and the diameter of the blood vessel is measured based on the echo image, so that the echo image and the cuff before the cuff pressure is applied Based on the echo image after the pressure release, the degree of expansion of the blood vessel diameter by the blood flow-dependent vasodilation reaction can be measured. In other words, when measuring the degree of expansion of the blood vessel diameter (so-called% FMD) by this blood flow-dependent vasodilation reaction, the above-described effects can be obtained.

  According to the blood vessel diameter measuring method using the echo according to the third invention of the present application, the ischemic cuff pressure for blocking the first portion in the arm portion of the subject based on the highest blood pressure of the subject. Since it is set, it is possible to surely block blood and to set a baffle cuff pressure as low as possible according to individual subjects. As a result, it is possible to effectively avoid excessive pain and burden on the measurement subject, as in the case of conventional ischemia by applying a uniform high cuff pressure.

  According to the blood vessel diameter measuring method using an echo according to the fourth invention of the present application, the blood pressure of the measurement subject is measured during the pressure control of the cuff pressure, so the blood vessel diameter measurement and the blood pressure measurement are performed together. Therefore, the convenience is improved as compared with the case where both are performed separately, and the latest blood pressure data of the measurement subject at the time of measuring the blood vessel diameter can be obtained.

  In these cases, the measurement subject's pulse pressure is detected while increasing the cuff pressure to the first part, and the cuff pressure at the time when the pulse pressure disappears is detected, so that the measurement subject's maximum pressure is detected. A cuff pressure corresponding to high blood pressure can be detected. That is, the highest blood pressure of the measurement subject can be measured in the step of applying the cuff pressure. Then, by setting the ischemic cuff pressure based on the detected value of the cuff pressure corresponding to the maximum blood pressure, the ischemic cuff pressure is set based on the maximum blood pressure of the measurement subject immediately before measuring the blood vessel diameter. be able to.

  In the above case, by setting the first part as the forearm part and the second part as the upper arm part, the blood vessel of the upper arm part (e.g. For the brachial artery, radial artery, etc.), the degree of vascular diameter expansion can be measured. In other words, when measuring the degree of expansion of the blood vessel diameter (so-called% FMD) by the blood flow-dependent vasodilatation reaction with respect to the blood vessel of the upper arm, the above-described effects can be obtained.

  According to the blood vessel diameter measuring apparatus using the echo according to the fifth invention of the present application, the echo probe of the imaging means is arranged along the direction in which the longitudinal direction of the ultrasonic wave emitting portion is substantially orthogonal to the center line of the blood vessel. In such a state, a fixing means for fixing the measurement subject's blood vessel flows is provided, so an echo image along a plane substantially perpendicular to the blood vessel center line (short axis side echo image) Even if a slight error occurs in the orientation setting (set) of the ultrasonic wave emitting portion of the echo probe, the obtained echo image always includes the diameter portion of the blood vessel. Therefore, unlike the conventional case where an echo image of the surface including the center line of the blood vessel (the echo image on the long axis side) has been imaged, a high level of skill is not required for the echo probe set (orientation setting). The blood vessel diameter can be easily measured.

  In this case, it is preferable that the apparatus further includes coordinate conversion display means that can convert and display the echo image of the blood vessel displayed in the xy coordinate system into a polar coordinate system with the blood vessel center on the image as the origin. Therefore, in a normal case (xy coordinate system), a substantially circular blood vessel edge can be displayed in a substantially straight line, and the blood vessel edge can be detected and the blood vessel diameter can be measured more easily and accurately. . If the origin at the time of polar coordinate conversion deviates to some extent from the actual center of the blood vessel, or if the blood vessel edge on the echo image is distorted or deformed, it will appear as a linear distortion or deformation in the polar coordinate display However, by calculating the average diameter of the blood vessel by the calculation means based on the detection data of the blood vessel edge detected on the echo image displayed in the polar coordinate display, the straight line distortion and deformation are canceled out, and the more accurate blood vessel The diameter can be determined more easily.

  Further, in this case, a luminance deviation is predetermined based on the moving average filter that performs high-frequency noise removal processing on the echo image displayed in polar coordinates and the luminance information of the image data of the echo image that has been subjected to high-frequency noise removal processing. By providing edge recognition means for recognizing a position larger than the value as a blood vessel edge, the accuracy of detecting the blood vessel edge can be further improved, and the position deviation of the blood vessel edge of the entire blood vessel wall surface is less than a certain value. By further including a misrecognized position exclusion unit that excludes a large position as a misrecognized position, the detection accuracy of the blood vessel edge can be further enhanced.

  In these cases, more preferably, the coordinate conversion display means can reversely convert the echo image of the polar coordinate display into the xy coordinate system, and therefore the echo image obtained by the reverse conversion is converted into the original x-. A more accurate blood vessel diameter can be obtained by correcting the blood vessel edge detection data based on the result of comparison with the echo image of the y coordinate display.

  In the above case, more preferably, a circular template displaying a circle substantially corresponding to an edge of a blood vessel on the echo image displayed in the xy coordinate system and the center of the circle, and the circular template By moving the circular template so as to approximately overlap the edge of the blood vessel on the echo image by moving the circular template on the echo image, the center of the circular template is assumed to be the blood vessel center. The origin can be set more easily when performing polar coordinate conversion.

  A circular template displaying a circle substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system and the center of the circle, and a diameter variable means for changing the diameter of the circular template; A moving means for moving the circular template on the echo image, and by adjusting the diameter of the template so that the template approximately overlaps the edge of the blood vessel on the echo image; The diameter of the blood vessel can be easily obtained.

  According to the blood vessel diameter measuring apparatus using an echo according to the sixth invention of the present application, when capturing an echo image, the image data storing means stores image data of a predetermined number of frames immediately after the echo image is frozen. Therefore, it is possible to detect at least one of the diastolic phase and the systolic phase of the blood vessel based on the image data of a predetermined number of frames immediately after the echo image freeze stored in the storage unit, Therefore, it is possible to detect the diastolic phase and the systolic phase of the blood vessel without the necessity of separately measuring and synchronizing the heartbeat of the blood vessel without requiring a large-scale and complicated device. In addition, since synchronous measurement with an electrocardiograph is unnecessary, a high level of skill is not required for measurement work.

  In this case, preferably, by further providing a template having a size approximate to the diameter of the blood vessel on the echo image, each of the predetermined number of frames of image data is relatively compared with the template as a reference, and the blood vessel is expanded. At least one of the systole and the systole can be detected, and the diastole or systole of the blood vessel can be detected more easily.

  More preferably, it comprises a detecting means for automatically detecting at least one of the diastolic phase and the systolic phase of the blood vessel based on the luminance information of each image data of the predetermined number of frames. The systole can be detected more quickly, and the detection work can be saved.

  In the above case, more preferably, the predetermined number of frames corresponds to a time equal to or longer than the heartbeat cycle of the person being measured, so that the diastolic period of the blood vessel corresponding to at least one cycle of the heartbeat of the person being measured. In addition, the systole can be detected, and when measuring the maximum diameter or the minimum diameter of the blood vessel, the heart rate measurement of the measurement subject by the electrocardiograph can be made unnecessary.

  In all of the above cases, the cuff pressure is applied to the first part in the arm of the measurement subject and is blocked for a predetermined time, and then the cuff pressure is released. At a predetermined timing before the cuff pressure is applied and after the cuff pressure is released. Then, an echo image of a predetermined blood vessel flowing through the second part in the arm portion of the measurement subject is captured, and the diameter of the blood vessel is measured based on the echo image, so that the echo image and the cuff before the cuff pressure is applied Based on the echo image after the pressure release, the degree of expansion of the blood vessel diameter by the blood flow-dependent vasodilation reaction can be measured. In other words, when measuring the degree of expansion of the blood vessel diameter (so-called% FMD) by this blood flow-dependent vasodilation reaction, the above-described effects can be obtained.

  According to the blood vessel diameter measuring apparatus using an echo according to the seventh invention of the present application, the device is provided with the ischemic cuff pressure setting means for setting the ischemic cuff pressure based on the highest blood pressure of the subject. The first site in the arm of the measurer can be reliably ischemic, and the ischemic cuff pressure as low as possible can be set according to the individual subject. As a result, it is possible to effectively avoid excessive pain and burden on the measurement subject, as in the case of conventional ischemia by applying a uniform high cuff pressure.

  According to the blood vessel diameter measuring apparatus using the echo according to the eighth invention of the present application, since the blood pressure measuring means for measuring the blood pressure of the measurement subject is provided during the control of the cuff pressure, the blood vessel diameter measurement and the blood pressure are measured. The measurement can be performed together, and convenience is improved as compared with the case where both are performed separately, and the latest blood pressure data of the measurement subject at the time of measuring the blood vessel diameter can be obtained.

  In these cases, it is preferable that a pulse pressure detection unit that detects the pulse pressure of the subject to be measured when the cuff pressure is increased to further increase the cuff pressure of the subject to be measured while increasing the cuff pressure to the first portion. The cuff pressure at the time when the pulse pressure disappears after detecting the pulse pressure can be detected, and the cuff pressure corresponding to the maximum blood pressure of the measurement subject can be detected. That is, the highest blood pressure of the measurement subject can be measured in the step of applying the cuff pressure. Then, by setting the ischemic cuff pressure based on the detected value of the cuff pressure corresponding to the maximum blood pressure, the ischemic cuff pressure is set based on the maximum blood pressure of the measurement subject immediately before measuring the blood vessel diameter. be able to.

  According to the blood vessel diameter measuring apparatus using the echo according to the ninth invention of the present application, the blood vessel by the blood flow-dependent vasodilation reaction based on the echo image before applying the cuff pressure and the echo image after releasing the cuff pressure. Display means capable of displaying the vascular diameter dilatation degree in time series is connected to the computing means capable of calculating the dilatation degree of diameter (so-called% FMD), so that% FMD measurement is performed periodically, for example. In the case of examining the change, improvement or deterioration of% FMD can be easily visually recognized as time series data.

  In the above case, by setting the first part as the forearm part and the second part as the upper arm part, a blood vessel diameter expansion phenomenon due to a blood flow-dependent vasodilation reaction is likely to appear remarkably (for example, , The degree of expansion of the blood vessel diameter can be measured for brachial artery, radial artery, and the like. In other words, when measuring the degree of expansion of the blood vessel diameter (so-called% FMD) by the blood flow-dependent vasodilatation reaction with respect to the blood vessel of the upper arm, the above-described effects can be obtained.

  According to the blood vessel diameter measuring apparatus using an echo according to the tenth invention of the present application, the fixing means for fixing the echo probe of the imaging means to the site where the blood vessel of the measurement subject flows, and the fixing state of the echo probe Since there is an adjusting means capable of adjusting the direction in which the blood vessel flows and the circumferential direction of the blood vessel, the echo probe can be used even when it is necessary to fix the echo probe to the measurement subject for a relatively long time. It is possible to adjust so as to keep the adhesion between the surface and the above-mentioned part constant, and more accurate measurement can be performed.

  According to the blood vessel diameter measuring apparatus using an echo according to the eleventh invention of the present application, a fixing means for fixing the echo probe of the imaging means to a site where the blood vessel of the measurement subject flows, and the measurement subject of the measurement subject Since there is a water bag interposed between the surface of the part and the ultrasonic emission surface of the echo probe, the surface shape of the part to be measured (for example, the arm part of the measurement person) and the ultrasonic emission surface Even if it is difficult to obtain good adhesion by direct contact, the orientation of the ultrasonic emission surface of the echo probe is set by interposing a water bag with shape flexibility between them. Can be easily maintained stably and properly, and a good set state can be easily obtained with respect to the set state of the echo probe and the measurement subject.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example the case where the embodiment is applied to measurement of blood vessel dilatation (% FMD) by blood flow-dependent vasodilatation (so-called FMD), for example. explain.
1 and 2 are an explanatory diagram and a block configuration diagram schematically showing a system configuration of the blood vessel diameter measuring apparatus Ms according to the present embodiment. The blood vessel diameter measuring device Ms captures an echo image of a predetermined blood vessel (typically brachial artery) of the measurement subject and measures the diameter of the blood vessel based on the echo image, thereby measuring the measurement subject. % FMD is measured, and the arm pressing mechanism 10, the probe fixing mechanism 20, the imaging mechanism 30, the control arithmetic mechanism 40, and the display mechanism 50 are provided as main parts.

  In particular, when measuring with the prediction of arteriosclerosis in mind, as the predetermined blood vessel of the subject to be measured, the blood vessel dilation phenomenon due to the blood flow-dependent vasodilation reaction is very remarkable. The brachial artery, which is easy to appear in, is representative. Alternatively, the degree of expansion (% FMD) of the radial diameter of the radial artery may be measured instead.

The arm pressurizing mechanism 10 is a mechanism whose basic purpose is to apply a cuff pressure to the first predetermined portion Af (first portion) in the arm portion of the person to be measured to block the first portion. And a cuff portion 11 made of an ischemic cuff and a cuff pressure control portion 12 for controlling the pressure in the cuff 11. Further, a base portion 14 on which the first part Af of the arm portion of the measurement subject is placed is provided below the cuff portion 11.
The first portion is typically the forearm portion Af of the measurement subject, and is not limited to this, but in this embodiment as well, the cuff pressure is applied to the forearm portion Af to prevent blood loss. did.

  Although not specifically shown, the cuff pressure control unit 12 controls the pressurizing mechanism that pressurizes the cuff 11, the depressurizing mechanism that depressurizes and depressurizes the cuff 11, and the pressurizing / depressurizing device. And a control mechanism. More specifically, the cuff pressure control unit 12, for example, a compression pump that supplies pressurized (compressed) air into the cuff 11 and a compressed air in the cuff 11 to depressurize and depressurize. An exhaust valve, and the operation of the compression pump and the exhaust valve is controlled by the controller of the cuff pressure control unit 12.

  The cuff part 11 has the same pressurization and decompression mechanism as that conventionally known, but in the present embodiment, the cuff part 11 is provided with a pulse pressure measurement part 13. The pulse pressure measuring unit 13 measures the pulse pressure of the measurement subject and detects the cuff pressure when the pulse pressure is generated and disappears, thereby measuring the minimum blood pressure and the maximum blood pressure of the measurement subject. it can. The case where the cuff pressure is increased will be described in detail by way of example. Starting from cuff pressure zero (0: zero), the cuff pressure at the time point when the pulse pressure measurement unit 13 detects the occurrence of the pulse pressure is measured to minimize the cuff pressure. The blood pressure can be known, then the cuff pressure is further increased, and the maximum blood pressure can be known by measuring the cuff pressure when the pulse pressure measurement unit 13 detects the disappearance of the pulse pressure.

  As described above, by providing the pulse pressure measurement unit 13 in the cuff unit 11, it is possible to perform both the measurement of% FMD and the blood pressure measurement, and the convenience is improved as compared with the case where both are performed separately. In addition, the latest blood pressure data of the person to be measured when measuring the blood vessel diameter can be obtained.

  In the present embodiment, the ischemic cuff pressure for blocking the forearm portion Af is set based on the highest blood pressure of the measurement subject measured by the pulse pressure measuring unit 13. That is, the ischemic cuff pressure is set to a pressure corresponding to a value higher than the maximum blood pressure by a predetermined value (specifically, 20-40 mmHg, more certainly 30-40 mmHg). By applying a cuff pressure corresponding to a value that is higher than the maximum blood pressure by the predetermined value, it is possible to reliably block the subject.

The setting of the ischemic cuff pressure is performed according to a control program of the control calculation mechanism 40 described later. Alternatively, a memory (storage device) storing a program for controlling the cuff pressure applied to the cuff pressure control unit 12 is attached, and the control program is used to control the cuff pressure and set the ischemic cuff pressure. May be.
In addition, when setting the ischemic cuff pressure based on the person's systolic blood pressure in this way, the person's memorized maximal blood pressure value from the past measurement experience is used without performing the actual measurement as described above. The ischemic cuff pressure may be set based on the reported value.

  In this way, by setting the ischemic cuff pressure based on the maximum blood pressure of each individual person to be measured, the forearm portion Af of the person to be measured can be reliably occluded and the ischemic cuff pressure as low as possible can be individually measured. It can be set according to. As a result, it is possible to effectively avoid excessive pain and burden on the measurement subject, as in the case of conventional ischemia by applying a uniformly high cuff pressure.

  In this case, the pulse pressure of the person to be measured is detected while increasing the cuff pressure of the forearm Af, and the cuff pressure at the time when the pulse pressure disappears is detected to correspond to the maximum blood pressure of the person to be measured. The detected cuff pressure can be detected. That is, the highest blood pressure of the measurement subject can be measured in the step of applying the cuff pressure. Then, by setting the ischemic cuff pressure based on the detected value of the cuff pressure corresponding to the maximum blood pressure, the ischemic cuff pressure is set based on the maximum blood pressure of the measurement subject immediately before measuring the blood vessel diameter. be able to.

  The probe fixing mechanism 20 is a mechanism for fixing the echo probe 31 to the second portion Au in the arm portion of the measurement subject, and the upper arm portion Au of the measurement subject is representative as the second portion. In other words, the brachial artery is a representative blood vessel for measuring arteriosclerosis by measuring% FMD, and is not limited to this, but also in the present embodiment, the brachial artery Au The echo probe 31 was fixed and the blood vessel diameter of the brachial artery was measured.

  In the present embodiment, the ultrasonic emission surface 31f (ultrasonic emission part) of the echo probe 31 is formed to have a substantially rectangular shape, and the probe fixing mechanism 20 has a longitudinal direction of the ultrasonic emission part 31f. It is configured so that the echo probe 31 can be fixed to the upper arm portion Au of the measurement subject in a state set along the direction substantially perpendicular to the center line of the brachial artery (that is, the thickness direction of the upper arm portion Au). ing.

  Specifically, as shown in FIG. 1, the probe fixing mechanism 20 includes, for example, a rod-like attachment 21 whose one end is supported on the base portion 14 of the arm pressing mechanism 10 and a terminal of the attachment 21. And a probe fixture 27 disposed on the side. The attachment 21 includes a horizontal portion 22 that extends horizontally from the base portion 14, an intermediate portion 23 that is bent at an angle of about 90 degrees, and a vertical portion 24 that extends in a direction substantially perpendicular to the horizontal portion 22. It has. The one end portion of the horizontal portion 22 is more preferably supported so as to be slidable in the extending direction with respect to the base portion 14.

The horizontal portion 22 and the intermediate portion 23 are connected so as to be relatively rotatable in a vertical plane via a first joint 25, and the intermediate portion 23 and the vertical portion 24 are in a horizontal plane via a second joint 26. And are connected so as to be relatively rotatable. The probe fixture 27 is fixed to the terminal side of the vertical portion 24.
Therefore, the position and orientation of the echo probe 31 fixed to the probe fixture 27 can be adjusted with respect to the direction of the brachial artery of the upper arm Au of the subject and the circumferential direction of the brachial artery.

  The probe fixture 27 is fixed at a predetermined angle with respect to the vertical portion 24 of the attachment 21, and the echo probe 31 is adjusted by adjusting the rotation angles of the first joint 25 and the second joint 26. The longitudinal direction of the ultrasonic wave emitting portion 31f can be easily set so as to be along a direction substantially orthogonal to the center line of the brachial artery (that is, the thickness direction of the brachial portion Au), and the position and orientation of the echo probe 31 can be set. In the state set in this way, it can be fixed to the upper arm Au of the measurement subject.

  Further, by providing the attachment 21 with the adjustment function as described above, even when the echo probe 31 needs to be fixed to the upper arm Au of the measurement subject for a relatively long time, the surface of the echo probe 31 and the upper arm It becomes possible to adjust so that the adhesiveness with Au is kept constant, and more accurate measurement can be performed.

  FIG. 4 schematically shows the relationship between the mounting orientation of the echo probe 31 with respect to the blood vessel Bv and the echo image to be captured. 4, the echo probe 31 is set (that is, the long axis) so that the longitudinal direction of the ultrasonic wave emitting portion 31f coincides with the plane including the center line Lb (long axis) of the blood vessel Bv. When the image is taken (on the side), an echo image of the blood vessel diameter D can be obtained for a length substantially corresponding to the length of the echo probe 31, and the value of the blood vessel diameter calculated based on these echo images is averaged Thus, even when the rate of change due to the vasodilation reaction is small as described above (about 10%), the blood vessel diameter can be obtained with relatively high accuracy. However, in order to obtain a clear echo image along the long axis of the blood vessel, it is necessary to search for a position where the echo signal coincides with the diameter D of the blood vessel Bv. In order to set the echo probe so that the echo passes along the diameter position of the blood vessel, considerable skill is required.

  On the other hand, as shown in the diagram on the left side in FIG. 4, the echo probe 31 is set so that the longitudinal direction of the ultrasonic wave emitting portion 31f is along the direction substantially orthogonal to the center line Lb of the blood vessel Bv. When the image is taken (that is, on the short axis side), even if a slight error occurs in the azimuth setting (set) of the ultrasound emitting unit 31f of the echo probe 31, the obtained echo image shows the blood vessel Bv. The diameter D portion is necessarily included. Therefore, a high skill level is required for the set (orientation setting) of the echo probes 31 as in the case where an echo image (long-axis side echo image) of a surface including the center line Lb of the blood vessel Bv has been conventionally captured. The blood vessel diameter D can be easily measured.

  In addition, since the ultrasonic emission surface 31f of the echo probe 31 is generally flat, it is difficult to set the probe 31 so as to be sufficiently in close contact with the surface shape of the curved arm, and an echo image of the blood vessel is captured. In some cases, it may be difficult to obtain a stable image. In such a case, for example, as schematically shown in FIG. 5, a bag body 28 (water bag) filled with water between the surface of the upper arm portion Au of the measurement subject and the launch surface 31 f of the echo probe 31. ). The water bag 28 is deformable, and when it is pressed against the surface of the arm, it easily adheres along the surface. Therefore, by using such a shape flexibility of the water bag 28, it is possible to relatively easily obtain a good set state with respect to the arm portion of the probe 31.

  On the other hand, the imaging mechanism 30 captures an echo image of a blood vessel to be measured (in this embodiment, the brachial artery flowing through the upper arm Au), and includes the echo probe 31 and the echo image processing device 32 described above. ing. The echo probe 31 emits an ultrasonic wave of a predetermined frequency (for example, 7.5-15 MHz) from the emitting surface 31f at the tip thereof, and receives the reflected wave as an echo signal. This echo signal is the image processing device 32. To obtain an echo image. As the imaging mechanism 30 (that is, the echo probe 31 and the image processing device 32) itself, for example, the same one as that conventionally known, such as the one disclosed in Patent Document 1 described above, can be used.

  The control calculation mechanism 40 controls the arm pressing mechanism 10 and the imaging mechanism 30 and calculates the diameter of the blood vessel (brachial artery) to be measured based on the echo image obtained by the imaging mechanism 30. For example, a microcomputer is the main part. More specifically, as shown in detail in FIG. 3, the control calculation mechanism 40 includes a cuff pressure setting unit 41, a pulse wave calculation unit 42, and a blood vessel diameter calculation as basic components for performing the operation. A unit 43, a determination unit 44, and a display processing unit 45 are provided.

  The cuff pressure setting unit 41 receives the measurement signal from the pulse pressure measurement unit 13 of the arm pressurizing mechanism 10 and detects the lowest blood pressure and the highest blood pressure of the measurement subject. Set the ischemic cuff pressure based on hypertension. As described above, more preferably, the cuff pressure can be set based on the systolic blood pressure reported by the measurement subject, and the cuff pressure setting unit 41 stores the maximum blood pressure value reported by the measurement subject. Manual input means (not shown) for inputting is connected so as to be able to send and receive signals. A setting signal from the cuff pressure setting unit 41 is input to the cuff pressure control unit 12 of the arm pressing mechanism 10.

  The pulse wave calculation unit 42 receives a measurement signal from the pulse pressure measurement unit 13 of the arm pressurizing mechanism 10, an image data signal from the image processing device 32 of the imaging mechanism 30, and preferably from the cuff pressure setting unit 41. An output signal is received, and based on these received signals, a pulse wave is detected and a pulse wave period is calculated, and a specific pulse wave such as an R wave of a heartbeat is detected. An output signal from the pulse wave calculation unit 42 is input to the blood vessel diameter calculation unit 43 and the determination unit 44.

  The blood vessel diameter calculation unit 43 calculates the average blood vessel diameter of the blood vessel to be measured based on the output signal from the pulse wave calculation unit 42 and the image data signal from the image processing device 32 of the imaging mechanism 30 and will be described later. Selection of a circular template, noise removal, identification of a blood vessel wall edge, and the like are also performed by the blood vessel diameter calculator 43. An output signal from the blood vessel diameter calculation unit 43 is input to the determination unit 44.

  The determination unit 44 discriminates the diastole and the systole of the blood vessel to be measured based on the output signals from the blood vessel diameter calculator 43 and the pulse wave calculator 42, calculates the average blood vessel diameter in each, and changes The rate (% FMD) is calculated. More preferably, the health condition of the measurement subject can also be determined based on the calculation result and the like.

  The display processing unit 45 outputs a display signal corresponding to the display operation based on a display operation signal from the display mechanism 50 (the monitor display unit 51 and the printer 52) described below. The determination signal from the determination unit 44 and the image data signal from the image processing device 32 are input. And according to the display operation signal from the display mechanism 50, a required display signal is combined or it outputs independently. For example, a specific pulse wave such as a pulse wave, a pulse wave period, and a heartbeat R wave detected by the pulse wave calculation unit 42 and blood vessel image data at a specific timing are displayed side by side on the same display screen. Or output as a hard copy.

  Although not specifically shown, the control calculation mechanism 40 includes a storage device storing a required program such as a control program, control data from the cuff pressure control unit 12, and measurement by the pulse pressure measurement unit 13. Various storage devices such as a storage device for storing data, blood vessel diameter calculation data, and the like are attached. The microcomputer of the control operation mechanism 40 is provided with various timer circuits for performing each measurement step in a time determined by the control program. Details of the overall operation and function of the control arithmetic mechanism 40 will be described later in more detail.

  A display mechanism 50 including a monitor display unit 51 and a printer 52 is connected to the control arithmetic mechanism 40 so as to be able to exchange signals. The monitor display unit 51 has, for example, a liquid crystal display screen, and can display various templates, which will be described later, on the screen in addition to an echo image picked up by the image pickup mechanism 30, and can display control templates on the screen. The measurement result obtained by calculation by the mechanism 40 can also be displayed. Further, such an image or measurement result displayed on the screen of the monitor display unit 51 can be launched as a hard copy by the printer 52. For example, a so-called mouse 51m is connected to the monitor display section 51 as an operation means for performing screen operation of the monitor screen.

Next, various specific examples of the blood vessel diameter measuring apparatus will be described with reference to FIGS. In these specific examples, the blood vessel diameter measuring device Ms described with reference to FIGS. 1 to 5 is embodied as a product, and the basic configuration and operation are the same as those of the blood vessel diameter measuring device Ms described above.
6 to 9 show a first specific example. As shown in these drawings, the blood vessel diameter measuring device M1 according to the first specific example includes a measurement calculation unit Um and a fixed holding unit UH1, and both Um and UH1 are integrated using, for example, a synthetic resin as a material. Is formed.

  The measurement calculation unit Um performs the functions of a part of the imaging mechanism 30 (image processing device 32), the control calculation mechanism 40, and the display mechanism 50. In the case 1, the measurement calculation unit Um includes a micro of the image processing device 32 and the control calculation mechanism 40. An electric / electronic circuit such as an integrated circuit and a control circuit constituting a computer and a memory chip constituting a storage device are accommodated.

  Further, on the front surface portion of the case 1 of the measurement calculation unit Um, a display display as the monitor display unit 51, a plurality of operation switches 2 such as a paper discharge port 52d of the printer 52 and a power switch located on the rear surface thereof, and its display A plurality of lamps 3 such as a lamp and an alarm lamp, and a plurality of external input / output terminals 4 are provided. Further, a speaker 5 connected to a pulse pressure detecting microphone described later is attached to the side surface of the case 1. The monitor display unit 51 is connected with a so-called mouse 51m as an operation means for performing screen operations and the like.

On the other hand, as will be described later, the fixed holding unit UH1 functions as a part of the arm pressing mechanism 10, the probe fixing mechanism 20, and the imaging mechanism 30 (echo probe 31).
The fixed holding unit UH1 includes a semi-circular forearm support portion 61 for placing and supporting the forearm portion Af of the measurement subject, and a semicircular upper cross-section for placing and supporting the upper arm portion Au of the measurement subject. The support part 62 is provided, and both 61 and 62 are integrally formed so as to form a predetermined angle in a side view.

The angle between the two 61 and 62 is an angle at which the subject can be stably maintained in a restrained state with relatively little burden even when the subject is restrained on the arm (the forearm Af and the upper arm Au) for a long time. For example, about 130 degrees is preferable. Moreover, as an inclination angle which the upper arm support part 62 makes with respect to a horizontal surface, for example, an angle of about 20-30 degrees (more preferably about 25 degrees) is preferable.
At the time of measurement, the arm of the person to be measured is passed from the rear end side of the upper arm support portion 62 until the forearm portion Af is positioned on the forearm support portion 61 and the upper arm portion Au is positioned on the upper arm support portion 62. Is inserted and set.

The front end side portion 61f of the forearm support portion 61 and the rear end portion 62r of the upper arm support portion 62 can adjust the lengths of the forearm support portion 61 and the upper arm support portion 62 according to the length of the arm of the subject. Each is formed to be slidable in the front-rear direction.
Further, the substantially central portion of the forearm support portion 61 is formed in a cylindrical shape, and this cylindrical portion constitutes the cuff portion 11. As shown in FIG. 8, the cuff portion 11 includes, in order from the inside, a substantially cylindrical elastic cushion portion 64 that wraps the forearm portion Af of the person to be measured, and an airbag portion 65 that pressurizes the cushion portion 64 by filling with compressed air. The cover portion 66 that covers the outer peripheral portion of the airbag portion 65 is provided. In the cuff part 11, a part (lower half) of the cover part 66 constitutes the forearm support part 61.

A plurality of (for example, two) microphones 67 are preferably attached to the outer peripheral portion of the cushion portion 64 so as to detect a pulsation sound of a blood vessel flowing in the forearm portion Af. The microphone 67 is connected to the speaker 5 disposed on the side surface of the case 1 of the measurement / calculation unit Um, so that the amplified pulsating sound of the blood vessel in the forearm Af can be heard outside. Thereby, it is possible to detect the disappearance of the pulse pressure. The two microphones 67 are preferably set in the mounting position and direction so that the direction in which they are directed is substantially perpendicular.
Note that the pulse pressure may be detected using a pressure sensor instead of the microphone 67.

As shown in detail in FIGS. 7 and 9, the upper arm support portion 62 is provided with a water bag 68 on its inner side, and preferably a plurality (for example, two) of outer peripheral portions of the water bag 68. An echo probe 31 is provided. These two echo probes 31 are preferably set in the position and direction of the launch surface 31f so that the ultrasonic emission directions are substantially perpendicular.
Since the inside of the water bag 68 is only filled with water, there is no adverse effect such as causing noise at the time of ultrasonic measurement. By interposing it between the 31 flat ultrasonic emission surfaces 31f, even when the surface shapes of both are different, more stable measurement can be performed.

So-called echo gel or grease is applied between the water bag 68 and the ultrasonic emission surface 31f of the echo probe 31 in order to easily pass ultrasonic waves and to reliably fill minute gaps. The ultrasonic waves from the ultrasonic emission surface 31 f are surely transmitted to the water bag 68.
By interposing such a water bag 68, the measurement target part (upper arm Au in the present embodiment) of the measurement subject and the echo probe 31 are not in direct contact with each other, so that the measurement subject changes each time. The echo probe 31 does not need to be cleaned and disinfected, which is convenient from the viewpoint of maintaining hygiene.

As described above, the echo probe 31 is set so that the longitudinal direction of the ultrasonic wave emitting portion 31f is along the direction substantially orthogonal to the center line Lb of the blood vessel Bv (that is, on the short axis side). Is done.
As shown by the area surrounded by the broken line in FIG. 7, the echo probe 31 can adjust the attachment position and the attachment orientation in the region 69 within a certain range around the reference position for attachment to the upper arm support portion 62. It is configured.

That is, the position of the echo probe 31 can be moved in the longitudinal direction and the circumferential direction of the upper arm support portion 62, and more preferably, even if the position is constant, the orientation can be freely adjusted within a certain range ( That is, it is configured to be able to swing. As such an adjusting mechanism, various conventionally known structures can be used. Further, the above-described adjustable region 69 is more preferably set as a more suitable range based on experience values obtained in advance from measurements on a wide variety of measurement subjects.
By making the mounting position and mounting orientation of the echo probe 31 adjustable as described above, the echo probe 31 can be set to an optimal position and orientation, and more accurate measurement can be performed more easily. become.

  Of the switches 2 and lamps 3 provided in the measurement arithmetic unit Um, the power switch and the power lamp are pressure sensors (not shown) when the arm of the person to be measured is fixed to the fixed holding unit UH1. This is detected, and the power switch is automatically turned on according to the detection signal of the pressure sensor, and the power lamp can be turned on. In order to protect the device M1, a protection mechanism may be provided so that the power is not turned on unless the detection signal of the pressure sensor is input. Of course, the power may be manually turned on / off.

  Moreover, when the measurement subject's arm is separated from the fixed holding unit UH1 after the measurement, this can be detected by the pressure sensor, the power switch can be automatically turned off, and the power lamp can be turned off. The device portion that directly contacts the person to be measured, for example, the inner portion of the forearm support portion 61 or the upper arm support portion 62 may be automatically or manually cleaned and disinfected by, for example, alcohol spraying.

  Furthermore, when it is detected that an abnormality has occurred in the pulse pressure, blood pressure, or pulsation rate of the subject during the measurement period, for example during the ischemic period, the cuff pressure is automatically released immediately. Preferably, it can be configured to notify the surroundings by an alarm lamp, an alarm buzzer, or a display display. In this case, it is desirable that the cuff pressure can be urgently released manually.

Furthermore, an external TV signal, a video / DVD signal, an audio signal, or the like can be input to an external input terminal provided in the measurement calculation unit Um. Or images of calm scenery or the like can be displayed on the display screen 51.
In this case, the display screen 51 may be switched to two screens, and measurement information such as measurement and remaining time of ischemia may be displayed on one screen.

When all the measurements are completed, the measurement result is displayed on the display screen 51. This measurement result can be printed out as a hard copy by the printer 52.
It is also possible to send the measurement result to an external personal computer, a memory device, or a player of a recording medium such as MD, CD, or DVD for recording.

  Further, based on the measurement data stored in the storage device of the control calculation mechanism 40, the degree of expansion (% FMD) of the blood vessel diameter of the blood vessel to be measured can be displayed on the display screen 51 in time series, The display screen can be printed out as a hard copy by the printer 52. An example of such time-series display measurement data is shown in FIG.

In this way, by providing the display means (display screen 51, printer 52) that can display the degree of expansion (% FMD) of the blood vessel diameter of the measurement object in time series, the% FMD measurement is performed periodically, for example, and the change is made. In such a case, improvement or deterioration of% FMD can be easily visually recognized as time series data.
In particular, for early arteriosclerosis, when it is desired to know the polyphenol effect of wine and the antioxidant action of vitamin C or vitamin E within a certain period of time, it is very convenient and effective.

Next, a second specific example of the blood vessel diameter measuring apparatus will be described with reference to FIGS. In the following description, components having the same configuration as in the first specific example and having the same function are denoted by the same reference numerals, and further description thereof is omitted.
The blood vessel diameter measuring device M2 according to the second specific example includes a measurement calculation unit Um similar to the device M1 in the first specific example, and the cuff portion 11 has a vertically divided structure in the fixed holding unit UH2. It is the same except for.

  That is, in the apparatus M2 according to the second specific example, the forearm support portion 71 of the fixed holding unit UH2 is formed in a semicircular shape as a whole, and the cuff portion 11 is configured by attaching the upper cover 72. Projections 72t extending in the longitudinal direction are integrally formed on the pair of assembly surfaces 72f of the upper cover 72. On the other hand, on the assembly surface 71f of the forearm support portion 71, a groove portion 71g for fitting the projection 72t so as to be slidable in the front-rear direction is formed.

In this second specific example, the forearm portion Af of the person to be measured is placed on and supported by the forearm support portion 71 with the upper cover 72 removed, and then the protrusion 72 t of the upper cover 72 is placed on the forearm support portion 71. The cuff part 11 is assembled by making it fit with respect to the groove part 71g. Although not specifically shown, the outer arm of the forearm support portion 71 and the upper cover 72 are provided with fixing latches having a well-known structure in order to fix them in an assembled state. The forearm support portion 71 and the upper cover 72 are locked so as not to be detached by the locking metal fitting.
According to the blood vessel diameter measuring device M2 according to the second specific example, the forearm portion Af of the measurement subject is fixed to the fixed support unit UH2 as compared with the device M1 of the specific example 1 in which the cuff portion 11 is integrated. Can be easily fixed.

  12 and 13 show a blood vessel diameter measuring apparatus M3 according to a third specific example. The device M3 according to the third specific example includes a measurement calculation unit Um similar to the device M1 in the first specific example, and the cuff portion 11 is also divided into two vertically and can be opened and closed with respect to the fixed holding unit UH3. It is the same except for the point.

  That is, in the device M3 according to the third specific example, the forearm support portion 76 of the fixed holding unit UH3 is formed in a semicircular shape in its entirety, and the cuff portion 11 is configured by attaching the upper cover 77. A pivot shaft 76s for pivotally supporting the upper cover 77 so as to be openable and closable is integrally provided on the outer side of the upper portion of the forearm support portion 76, and the assembly surface 76f on the opposite side (inner side) has an upper side. A groove portion 76g for locking the cover 77 in the closed state is formed. The pivot shaft 76 s is provided so as to extend along the longitudinal direction of the forearm support portion 76.

On the other hand, on the left and right sides of the upper cover 77, a cylindrical portion 77c having an insertion hole into which the pivot shaft 76s is fitted is integrally provided, and the groove portion is formed on the assembly surface 77f on the opposite side. A protrusion 77t that fits 76g is formed, and an operation knob 77w is provided on the side thereof. The cylindrical portion 77 c is provided so as to extend along the longitudinal direction of the upper cover 77.
The upper cover 77 is assembled to the forearm support portion 76 by inserting the pivot shaft 76s through the insertion hole of the cylindrical portion 77c, and is supported to be openable and closable around the pivot shaft 76s.

In this third specific example, the forearm portion Af of the measurement subject is placed on the forearm support portion 76 with the upper cover 77 removed from the forearm support portion 76 or with the attached upper cover 77 opened. After placing and supporting the cuff portion 11, the upper cover 77 is closed and the projection 77 t is fitted into the groove 76 g of the forearm support portion 76. Although not specifically shown in the drawings, the outer arm of the forearm support portion 76 and the upper cover 77 are provided with fixing metal fittings having a well-known structure in order to fix both in the assembled closed state. The forearm support portion 76 and the upper cover 77 are locked so as not to be opened and closed by the locking bracket.
According to the blood vessel diameter measuring device M3 according to the third specific example, the forearm portion Af of the measurement subject is fixed to the fixed support unit UH3 as compared with the device M1 of the specific example 1 in which the cuff portion 11 is integrated. Can be easily fixed.

  The blood vessel diameter measuring devices M1 to M3 according to the first to third specific examples are not specifically shown, but are the same as those in the blood vessel diameter measuring device Ms shown in FIGS. A so-called mouse 51m is connected as an operation means for operating the monitor screen 51.

An outline of the% FMD measurement procedure using the blood vessel diameter measuring apparatus Ms (or M1, M2, M3) having the above-described configuration will be described with reference to the time charts of FIGS. 15 and 16 and the flowchart of FIG. To do.
First, the forearm portion Af of the person to be measured is fixedly held on the cuff portion 11 of the arm portion pressurizing mechanism 10, and the apparatus is turned on (FIG. 17: steps # 1 and # 2). Alternatively, the power is automatically turned on. And it keeps still for a predetermined period (for example, about 15 minutes or more). At the beginning of this rest period, the echo probe 31 for the upper arm Au of the subject is set (step # 3). When setting the echo probe 31, more preferably, the position and / or mounting orientation of the echo probe 31 is adjusted (for example, adjusted within the adjustable region 69 shown in FIG. 7), and the blood vessel Bv. An optimum measurement position for measuring the diameter of the (brachial artery) is searched, and the final position and / or mounting orientation is set (set).

  At this time, as described above, the echo probe 31 is set so that the longitudinal direction of the ultrasonic wave emitting portion 31f is along the direction substantially orthogonal to the center line Lb of the blood vessel Bv. Thereafter, the imaging mechanism 30 is operated at the end of the rest period, and an echo image (short-axis side image) of the blood vessel Bv (brachial artery) at the rest is taken, and this is stored in the storage device of the control calculation mechanism 40. (Step # 4).

  After capturing the resting echo image, the arm pressurizing mechanism 10 is operated to pressurize the forearm Af of the measurement subject and start blood pressure measurement (step # 5). That is, the pulse pressure measurement unit 13 measures the pulse pressure, the minimum blood pressure, and the maximum blood pressure of the measurement subject while gradually increasing the applied pressure (step # 6). These measured values are stored in a storage device (not shown) of the control calculation mechanism 40. Then, after measuring the maximum blood pressure, the pressure value is set to the ischemic cuff pressure obtained by adding a predetermined pressure (for example, a pressure corresponding to a blood pressure of about 20 to 40 mmHg) to the cuff pressure corresponding to the maximum blood pressure value ( Step # 7). By applying this ischemic cuff pressure, the forearm portion Af of the measurement subject is ischemic.

When the cuff pressure is increased (step # 8) and the set ischemic cuff pressure is reached, the timer is activated and this ischemic cuff pressure is maintained for a certain time (for example, 4.5 to 5 minutes) (step #). 9). Thereby, ischemia is performed for a certain time.
When this ischemic period elapses, the pressurized air in the cuff part 11 is rapidly exhausted and rapid decompression is performed. As a result, blood rapidly flows into the blood vessel that has been ischemic, and hyperemia starts (initiation of hyperemia reaction: step # 10). After this hyperemia reaction period is started, when a predetermined time (for example, about 45 seconds) elapses and a vasodilation reaction occurs, the imaging mechanism 30 is operated to capture an echo image of the expanded blood vessel Bv at the time of hyperemia. Then, this is stored in the storage device of the control arithmetic mechanism 40 (step # 11). The imaging in this hyperemia phase is performed, for example, within a period of about 15 seconds.

  The measurement ends here. After completion of the measurement, the restraint of the forearm portion Af of the measurement subject by the cuff portion 11 is released (step # 12). After that, more preferably, the device part that is in direct contact with the person to be measured, such as the inner part of the forearm support part or the upper arm support part, is automatically cleaned and disinfected by, for example, alcohol spraying, and then the power is turned off ( Step # 13). Such washing and disinfection may be performed manually.

In the above measurement, the cuff pressure is automatically controlled by the cuff pressure control unit 12 in accordance with a control program stored in the storage device of the control calculation mechanism 40. More preferably, the cuff pressure control program includes a cuff pressure correction program for automatically correcting and maintaining the ischemic cuff pressure when a decrease in the cuff pressure occurs during the ischemic period. It is included.
Based on the echo image at rest and the echo image at the time of hyperemia obtained by the above measurement, the blood vessel diameter of the brachial artery Bv at the time of rest and hyperemia is calculated by the control calculation mechanism 40, and the calculation of these blood vessel diameters. From the value,% FMD is calculated. The calculated values of the blood vessel diameter and% FMD are all stored in the storage device of the control calculation mechanism 40.

  FIG. 16 is a time chart showing an example of a change state of the vascular diameter of the brachial artery during the above measurement. As shown in this figure, the rate of change of the blood vessel diameter is typically maximum at about 45 seconds after the start of the hyperemia reaction (after the start of rapid cuff evacuation), and then this maximum rate of change is maintained for about 15 seconds. The Therefore, the measurement of the blood vessel diameter at the time of hyperemia is performed in about 15 seconds.

  In the case where an echo image of the blood vessel Bv is captured in the above measurement, in this embodiment, it is possible to avoid a complicated and large-scale apparatus and to perform measurement without requiring a high level of skill. Therefore, the diastolic phase and systolic phase of the blood vessel can be detected without performing the operation of separately measuring the heartbeat of the measurement subject with an electrocardiograph and synchronizing them. Next, detection of the diastolic phase and systolic phase of the blood vessel, particularly detection of the diastolic phase will be described.

In this embodiment, instead of measuring the heartbeat of the person to be measured with an electrocardiograph and synchronizing it, image data of a predetermined number of frames immediately after the echo image is frozen when the echo image is captured. And the diastole or systole of the blood vessel is detected based on the predetermined number of frames of image data. Such frame image data is stored in the storage device of the control calculation mechanism 40 described above.
As a result, it is not necessary to separately measure the heartbeat of the measured person with an electrocardiograph and to synchronize them. Therefore, without requiring a large and complicated device, the diastolic or systolic phase of the blood vessel Bv is required. Can be detected, and high skill is not required for the measurement work.

  The number of frame images to be stored immediately after freezing is preferably at least 60 (for example, about 60-120). Usually, since an echo image is displayed in 30 frames per second, if it is at least 60 frames, it corresponds to 2 seconds or more. On the other hand, even if the heart rate is 40, one beat is less than 2 seconds, and image data of at least 60 frames (corresponding to 2 seconds) is stored to save the entire one beat cycle. It is possible to reliably record the state of change over time.

  In this way, the number of frame images in which image data should be stored corresponds to a time longer than the heartbeat cycle of the measured person, thereby corresponding to at least one period of the heartbeat of the measured person. The diastolic phase and the systolic phase of the blood vessel can be reliably detected, and when measuring the maximum diameter and the minimum diameter of the blood vessel Bv, the measurement of the heartbeat of the measurement subject by the electrocardiograph can be made unnecessary. .

A specific method for measuring the maximum diameter of the blood vessel Bv from the frame image stored as described above will be described.
In the present embodiment, a template having a size approximate to the diameter of the blood vessel Bv on the stored echo image (frame image) is prepared, and each of the image data of the predetermined number of frames (for example, 60 frames) is used as the template. Is used as a reference to detect the diastole or systole of the blood vessel Bv.

FIG. 18 shows a template TP1 used when manually detecting the diastole or systole of the blood vessel Bv. The template TP1 is used by being superimposed on the image frame F (F1, F2,..., Fn), and includes two pairs of parallel straight lines S1 and S2 (line segments). It is configured to include one vertical line S3 (line segment) orthogonal to the line segments S1 and S2.
The template TP1 can be moved and operated on the display screen 51 by using an operation means such as a mouse.

  The interval Ds between the parallel line segments S1 and S2 is set to a value that approximates the diameter of the image Eb of the blood vessel Bv, and the relative size of the diameter of the blood vessel image Eb for the n image frames F is compared. The template TP1 is moved so that one of the two line segments S1 and S2 overlaps the blood vessel edge (edge) of the blood vessel image Eb, and the interval Ds between the line segments S1 and S2 of the template TP1 is used as a reference. The diameter of the blood vessel image Eb is observed. Note that the vertical line S3 is positioned so as to pass through the center of the blood vessel image Eb in terms of the amount of division, thereby facilitating the position setting of the parallel line segments S1 and S2.

  Then, the frame F is sequentially advanced on the screen 51 by key operation, and the interval Ds between the line segments S1 and S2 of the template TP1 is set for all the frames F (F1, F2,..., Fn) by the same method as described above. The diameter of the blood vessel image Eb as a reference is examined. Then, the frame image that seems to have the largest diameter is employed as the diastolic blood vessel image Eb based on the heartbeat of the measurement subject.

  In this way, each frame image F (F1, F2,..., Fn) having a predetermined number of frames is relatively compared with the template TP1 having a size approximate to the diameter of the blood vessel image Eb on the echo image (frame image). Thus, by detecting the diastole or systole of the blood vessel Bv, the diastole or systole of the blood vessel Bv can be detected more easily.

  Then, the extraction of the diastolic blood vessel image Eb based on the heartbeat of the measurement subject is performed on both the resting echo image and the echo image at the time of hyperemia, and the two are compared. In addition, it is possible to calculate the degree of expansion (% FMD) of the blood vessel Bv by the blood flow-dependent vasodilation reaction that eliminates the influence of the heartbeat of the measurement subject without having to synchronize with this.

The above method is for manually detecting the diastole or systole of the blood vessel Bv due to the heartbeat of the measurement subject. However, when the echo image (frame image) is clear, such detection is performed. It is also possible to perform this automatically based on the luminance information of each image.
As shown in FIG. 19, the template TP2 used in this automatic detection method includes line segments similar to the three line segments S1, S2, S3 provided in the manual detection template TP1, and a pair of parallel segments. The rectangular templates T1 and T2 are attached to the straight line segments (horizontal lines) S1 and S2, respectively.

The rectangular templates T1 and T2 attached to the horizontal lines S1 and S2 are set to a size that allows the vascular wall outer membrane portion to fit inside the rectangle in common throughout the entire frame layer. For example, the template TP2 is matched with the blood vessel image Eb of the uppermost frame F1.
As shown in FIG. 20, in the image frame layer, the diastolic phase and the systolic phase of the blood vessel due to the heartbeat of the measurement subject are displayed as a series of frame images F (F1,..., Fm,..., Fn). It is only necessary to detect the maximum expansion period frame.

Since the ultrasonic wave is emitted from the upper arm epidermis toward the deep part, in the blood vessel image Eb that is an image on the short axis side, as shown in FIG. 21, in the direction along the diameter of the blood vessel image Eb (y in FIG. 21) Direction).
In the rectangular frames T1 and T2 attached to the horizontal lines S1 and S2, the ± dH direction represents the echo depth direction with respect to the horizontal lines S1 and S2, and the ± dL direction with respect to the vertical line S3 represents the arm width. It represents the direction.

  When the ultrasonic wave emission unit 31f of the echo probe 31 is positioned on the upper surface side of the upper arm Au of the measurement subject and the ultrasonic wave is emitted, the echo is normally located on the upper side located on the side closer to the ultrasonic wave emission unit 31f. It is known that a maximum value (maximum luminance) is shown in the outer membrane portion of the blood vessel wall and the outer membrane portion of the lower blood vessel wall located on the far side, and the rectangular template T1 attached to the horizontal lines S1 and S2 , T2 are set to a size that allows the vascular wall outer membrane portion to be accommodated inside the rectangle in common throughout the entire frame layer, so that the two maximum luminance portions are all rectangular as illustrated in FIG. It will fit within the templates T1 and T2.

In each image frame F, a position (maximum luminance position) indicating the maximum luminance within a range of ± dH is detected for each pixel in the dL direction within the area of the rectangular templates T1 and T2, and the maximum luminance position is detected. To obtain positions Y1 and Y2 from the y direction. The distance Lf between the vascular wall outer membranes of each frame F is represented by Lf = Y1-Y2.
Since this Lf value is obtained for all the frames F (F1,..., Fm,..., Fn) and the image frame having the maximum Lf value is automatically extracted, the frame in the maximum expansion period can be automatically detected. is there.

The above automatic detection is executed by an automatic detection program stored in the storage device of the control arithmetic mechanism 40.
As described above, by automatically detecting the diastole or systole of the blood vessel Bv based on the luminance information of each frame image F of a predetermined number (for example, 60 to 120 frames), the diastole or systole of the blood vessel can be detected more quickly. In addition, the detection work can be greatly saved.

  Normally, as described above, the echo shows the maximum value in the outer membrane portion of the upper blood vessel wall and the outer membrane portion of the lower blood vessel wall, and the maximum luminance portion appears in these portions. When the blood vessel Bv is calcified by plaque or the like, the maximum luminance portion may appear in the intima portion of the blood vessel wall. Therefore, when detecting the diastole or systole of the blood vessel Bv, it is desirable for the examiner to determine whether it should be performed automatically or manually, and to select any suitable method.

  As described above, blood flow-dependent blood vessels that eliminate the influence of the subject's heartbeat by extracting the images of the vasodilation due to the subject's heartbeat from the resting and hyperechoic echo images Although the degree of expansion (% FMD) of the blood vessel Bv due to the expansion reaction can be calculated, in the present embodiment, when an echo image of the blood vessel Bv is captured, as described above, the longitudinal direction of the ultrasonic wave emitting unit 31f The echo probe 31 is set so as to be along a direction substantially perpendicular to the center line Lb of the blood vessel Bv, and an echo image (short-axis side image) is taken.

  Thereby, compared with the conventional case where the echo image (the image on the long axis side) of the surface including the center line Lb of the blood vessel Bv is imaged, a high level of skill is not required for the set of echo probes 31, and the blood vessel Although the diameter can be easily measured, on the other hand, in the imaging of the echo image on the short axis side, since the portion where the echo passes through the diameter of the blood vessel Bv is very small, as in the case of the echo image on the long axis side. It is difficult to obtain the average of the measured values and maintain the measurement accuracy.

Therefore, in the present embodiment, the measurement value is obtained for the entire circular blood vessel image (the entire circumference) in the echo image on the short axis side, and the average is obtained to ensure the measurement accuracy.
Therefore, in this embodiment, the echo image of the blood vessel Bv displayed in the xy coordinate system is converted into the polar coordinate system and displayed, and the edge of the blood vessel Bv to be measured is detected based on the echo image of the polar coordinate display. By doing so, detection of the blood vessel edge and measurement of the blood vessel diameter can be performed more easily and accurately.

FIG. 23 is a known diagram for explaining the relationship between the xy coordinate system and the polar coordinate system. As shown in this figure, a point P displayed with coordinates (dx, dy) in the xy coordinate system is displayed with coordinates (r, θ) in the polar coordinate system.
When this polar coordinate display is used, for example, the curve C1 and the outer frame line G1 as shown in FIG. 24 in the xy coordinate system are converted into a polar coordinate system having the point P1 as the origin, thereby being shown in FIG. Such a curve C2 and a curve G2.

  When such coordinate conversion is applied to a circle, the circle J1 and the outer frame line K1 displayed in the xy coordinate system of FIG. 26A are converted into a polar coordinate system with the center P1 of the circle J1 as the origin. If it represents, it represents with the straight line J2 and the curve K2 as shown in FIG.26 (b). In this case, the radius R of the circle J1 in FIG. 26A is represented as the distance R between the straight line J2 and the reference line Lj in FIG. 26B, and the diameter can be obtained by doubling this.

Further, in the case where the point P2 slightly deviated from the center P1 of the circle is converted into the polar coordinate system and displayed, the curve J3 and the curve K3 are slightly distorted from the straight line as shown in FIG. Represented. In this case, the radius R of the circle J1 in FIG. 26 (a) is represented by the average value of the distance R between the curve J3 and the reference line Lj in FIG. 26 (c). can get.
Thus, even when the polar coordinate conversion is performed with the point P2 slightly deviated from the center P1 of the circle as the origin, by taking the average value of the distance R between the obtained curve J3 and the reference line Lj, it is deviated from the center P1 of the circle. The distortion of the straight line caused by setting the point P2 as the origin can be canceled out, and the decrease in accuracy can be compensated.

Therefore, an average diameter is measured for an approximately circular but accurate circle, such as a blood vessel image Eb imaged on the short axis side as shown in FIG. 27, with a shape whose center cannot be clearly specified. In such a case, as shown in FIG. 28, the center Pe of the circle is hypothesized and displayed after being converted into a polar coordinate system to display and recognize the edge (edge) of the blood vessel image Eb as a substantially straight line. It is possible to measure the average diameter relatively easily and accurately.
An example of such polar coordinate display is shown in FIG. In FIG. 29, the edge line of the blood vessel image Eb is displayed as a curve J formed by distorting a straight line, and the outer frame line of the image frame is displayed as a curve K.

Thus, by converting the echo image of the blood vessel Bv displayed in the xy coordinate system into a polar coordinate system with the blood vessel center on the image as the origin, and displaying it, the normal (xy coordinate system) Then, a substantially circular blood vessel edge can be displayed in a substantially straight line, and the detection of the blood vessel edge and the measurement of the diameter of the blood vessel can be performed more easily and accurately.
If the origin at the time of polar coordinate conversion deviates to some extent from the actual center of the blood vessel, or if the blood vessel edge on the echo image is distorted or deformed, it will appear as a linear distortion or deformation in the polar coordinate display However, by obtaining the average diameter of the blood vessel Bv based on the detection data of the blood vessel edge detected on the echo image displayed in the polar coordinate display, distortion and deformation of the straight line are offset, and a more accurate blood vessel diameter can be obtained. It can be easily obtained.

  In order to accurately measure the blood vessel diameter, it is important how to accurately recognize the blood vessel wall from the echo image obtained by imaging, but depending on the position of the blood vessel wall, In some cases, a misidentification of the blood vessel wall is likely to occur. That is, for example, in FIG. 27, if the emission direction of the echo is represented by an arrow Ah, the proximal and distal regions (particularly substantially the most proximal) of the blood vessel wall surface portion of the blood vessel image Eb with respect to the echo emission side. And for the most distal regions Eb1 and Eb2), reflected echoes are relatively easy to obtain and the blood vessel edges can be detected relatively clearly. On the other hand, in both the end regions Eb3 and Eb4 in the direction substantially orthogonal to the echo emission direction (arrow Ah direction) in the blood vessel wall surface portion of the blood vessel image Eb, it is relatively difficult to obtain reflected echoes. It is known that erroneous detection is likely to occur.

Therefore, in the present embodiment, more preferably, when performing coordinate conversion to the polar coordinate system, the blood vessel wall portion substantially closest to the echo emission side among the blood vessel wall portions of the blood vessel image Eb is set to 0 degrees. Then, coordinate conversion to the polar coordinate system is performed with the blood vessel wall portion substantially farthest from the echo emitting side as 180 degrees (see FIG. 29).
Thereby, in the blood vessel wall surface portion of the blood vessel image Eb, the region where the reflected echo is relatively easily obtained and the blood vessel edge can be detected relatively clearly (substantially the most proximal and distal regions Eb1 with respect to the echo emission side) And Eb2: Regions of 0 ° and 180 ° in polar coordinate display) and regions where reflected echoes are relatively difficult to be obtained and blood vessel edges are likely to be erroneously detected (both end regions Eb3, Eb4 in the direction orthogonal to the echo emission direction) In the polar coordinate display can be easily recognized in advance. Therefore, when detecting a blood vessel edge, it is possible to contribute to improvement in detection accuracy by paying special attention to the regions Eb3 and Eb4 that are likely to be erroneously detected.

  In the present embodiment, when virtualizing the center of the blood vessel image Eb, it substantially corresponds to the edge of the blood vessel image Eb on the echo image displayed in the xy coordinate system so that a virtual center can be set more easily and accurately. As a template to be prepared, a circular template TP3 displaying the center P3 as shown in FIG. 30 is prepared. As shown in FIG. 31, this circular template TP3 is superimposed on the blood vessel edge on the echo image, and this superposition is performed. The center P3 of the circular template TP3 is assumed to be the blood vessel center.

By virtualizing the blood vessel center using such a circular template TP3, the origin can be set more easily and accurately when the blood vessel image Eb displayed in the xy coordinate system is converted into polar coordinates.
In this case, in order to superimpose the edge of the blood vessel image Eb and the circular template TP3 with higher accuracy, the diameter of the circular template TP3 is preferably as close as possible to the diameter of the blood vessel image Eb to be measured. It is more preferable that the diameter is slightly larger than the diameter of the blood vessel image Eb.

FIG. 32 shows a circular template TP4 (center P4) having a variable diameter. In the case of this circular template TP4, the diameter can be changed (enlarged / reduced) in units of pixels, for example, by a mouse operation or the like.
As described above, when the diameter of the circular template TP4 substantially corresponding to the blood vessel edge on the echo image displayed in the xy coordinate system is variable, the template TP4 overlaps the blood vessel edge on the echo image with high accuracy. Thus, the diameter of the template TP4 can be adjusted, and the blood vessel center can be assumed more accurately.

  Instead of this, a plurality of circular templates whose diameters are invariable (not variable) are prepared, and the plurality of circular templates are sequentially replaced to overlap the edge of the blood vessel image Eb to be measured. The closest approximation to the diameter, more preferably the closest approximation and slightly larger than the diameter of the blood vessel image Eb, may be selected, and the blood vessel center may be assumed using this selected circular template. In this case, an exchange operation for sequentially exchanging a plurality of circular templates can be automatically performed by program control, which is preferable for promoting virtual automation of the blood vessel center.

By using the circular template TP3 or TP4 as described above, the blood vessel center in the blood vessel image Eb is virtualized, and conversion from the xy coordinate system to the polar coordinate is performed with this virtual center as the origin.
That is, as shown in FIG. 23, by detecting the luminance value along the r direction obtained by r = √ (dx · dx + dy · dy) and processing this for one rotation along the angle θ, for example, The blood vessel image Eb in the xy coordinate display as shown in FIG. 28 is converted into the polar coordinate display J as shown in FIG.

From the developed view (see FIG. 29) developed in polar coordinates in this way, the outer diameter edge of the blood vessel image Eb can be automatically recognized to calculate the blood vessel diameter.
FIG. 33 is a diagram for explaining automatic recognition of the epicardial edge of the blood vessel image Eb. In this figure, the vertical axis represents luminance, and the horizontal axis represents the distance from the origin Pe of polar coordinate conversion (virtual center of the blood vessel image in the xy coordinate display).

  When the epicardial edge of the blood vessel image Eb is automatically recognized from the polar coordinate development view, generally, the luminance peak appears not only in the epicardial edge portions NP and FP but also in the intimal edge portions Pi and Pi (see FIG. 33). In order to prevent the intima peak Pi from being erroneously detected, a smoothing process is performed on the polar coordinate development view. This smoothing process can be performed using a smoothing filter such as a moving average process. Thereby, small peaks such as the inner membrane peak Pi shown in FIG. 33 are removed, and only the remaining outer membrane peaks NP and FP can be detected.

  In the present embodiment, when performing the smoothing process on the polar coordinate development view, first, the high-frequency noise removal process is performed on the echo image of the polar coordinate display using the moving average filter, and the echo subjected to the high-frequency noise removal process Based on the luminance information of the image data of the image, a position where the luminance deviation is larger than a predetermined value is recognized as a blood vessel edge, and the position where the luminance deviation is not more than the predetermined value is not a point (pixel) representing the blood vessel edge. As to be excluded. In addition, with respect to the blood vessel edge of the entire blood vessel wall surface, a position where the position deviation is larger than a certain value is excluded as a misidentified position.

  In this way, based on the luminance information of the image data of the echo image subjected to the high frequency noise removal processing, the position where the luminance deviation is larger than the predetermined value is recognized as the blood vessel edge, thereby further improving the detection accuracy of the blood vessel edge. Further, with respect to the blood vessel edge of the entire blood vessel wall surface, the accuracy of detecting the blood vessel edge can be further enhanced by excluding the position where the position deviation is larger than a certain value as the misidentified position.

  In order to detect the epicardial edge line, the luminance change amount dz is compared with the minute change amount dr from the virtual center Pe of the blood vessel image Eb toward the blood vessel periphery along the radius r direction. At this time, a position where the luminance change amount dz is equal to or larger than a predetermined value is detected, and this is detected as an outer membrane edge position of the blood vessel (a so-called m-line located between the inner membrane and the outer membrane of the blood vessel Bv). To do. This entire m-line can be confirmed as a position showing the diameter of the blood vessel.

The radius of the blood vessel image Eb is obtained from the position information in the polar coordinate development view of the epicardial edge line thus detected, and the average value of the diameter of the blood vessel image Eb is obtained by doubling the average value of the radius. .
After obtaining the average value of the diameters in this way, more preferably, the polar coordinate development is inversely transformed into the original xy coordinate system, and the image obtained by the inverse transformation is converted into the blood vessel of the original xy coordinate display. Contrast with image.

  For example, when the original echo image is extremely unclear, automatic detection of the outer membrane edge line may not be performed properly. In such a case, the detected epicardial edge line can be obtained by comparing the blood vessel image of the xy coordinate display obtained by inverse conversion from the polar coordinate display with the blood vessel image of the original xy coordinate display. It is also possible to make corrections to remove some of the constituent points or add points to obtain an epicardial edge line that approximates the epicardial edge of the blood vessel image in the original xy coordinate display. is there. By adding such correction, a more accurate blood vessel diameter can be obtained.

  In addition, when it is judged from the state of the echo image that automatic detection of the outer membrane edge line as described above is impossible, or when simpler detection is required, the circular template TP4 having a variable diameter is used. The diameter of the blood vessel can be measured by superimposing the circular template PT4 on the outer membrane edge of the blood vessel image manually and visually while variably adjusting the diameter. Actually, it is most efficient to use such manual measurement in combination with the above-described automatic measurement function and a partial correction function thereof.

  FIG. 34 is a flowchart schematically showing the blood vessel diameter measurement routine as described above. When measurement is started, an arbitrary echo image is first extracted (step # 21), and an artery (blood vessel image) to be measured is extracted from luminance information of the image (step # 22). Next, a circular template that matches the extracted artery blood vessel image is selected (step # 23). As described above, the selection of the circular template is repeated until a template that is closest to the diameter of the virtual artery and larger than the diameter of the virtual artery is found by sequentially exchanging a plurality of circular templates and superimposing them on the blood vessel image (step). # 24). Then, the selected circular template is superimposed on the blood vessel image (virtual artery) to be measured, and the center of the circular template is recognized as the center of the virtual artery (step # 25).

  Next, polar coordinate conversion is performed with reference to the center of the virtual artery (step # 26), and a high-frequency noise removal process is performed on the polar coordinate display image using a moving average filter (step # 27). Then, a pixel exceeding a predetermined set luminance is recognized as a blood vessel edge (step # 28). That is, a position where the luminance deviation is larger than a predetermined value is recognized as a blood vessel edge, and a position where the luminance deviation is equal to or smaller than the predetermined value is excluded as a point (pixel) representing the blood vessel edge.

Further, the blood vessel edge in the polar coordinate display image is subjected to a moving average in the direction of 360 degrees, and the wall surface position where the position deviation is larger than a certain value is excluded as a false recognition position (miss detection position) (step # 29). ).
Based on the recognized blood vessel edge, the average value of the blood vessel diameter is calculated and recognized as the average blood vessel diameter at an arbitrary time (step # 30).
The measurement of the blood vessel diameter as described above is repeatedly performed at a predetermined timing and / or a predetermined time interval for each of the systole and the diastole of the blood vessel diameter.

As described above, based on the position information of the blood vessel edge obtained from the luminance information of the image data of the echo image (blood vessel image Eb) (that is, the average value of the diameter of the blood vessel image Eb), the diastole and the contraction of the blood vessel are described. At least one of the periods can be automatically detected. That is, by comparing the average diameters of a plurality of blood vessel images Eb obtained sequentially in time series, if the diameter of the subsequent image is larger, the blood vessel is in the diastole, while the diameter of the subsequent image If is smaller, it can be determined that the blood vessel is in systole.
Thereby, the diastole and the systole of the blood vessel can be detected more quickly, and the detection work can be saved.

Further, when estimating the diameter of the blood vessel at the maximum dilation, a gradual increase of the blood vessel diameter is linearly reverted based on a plurality of measured values of the expanded blood vessel diameter in the process of hyperemia and a measured value of the reference blood vessel diameter at rest. The maximum dilated vessel diameter can be estimated in a shorter time by estimating by the method and using the estimated value of the dilated vessel diameter corresponding to the hyperemia reaction time of 60 seconds as the maximum dilated vessel diameter.
Here, the estimated value of the dilated vessel diameter corresponding to the hyperemia reaction time of 60 seconds is used because the dilation of the blood vessel during the hyperemia reaction period usually saturates the dilation effect at least 60 seconds after the hyperemia reaction is started. Because.

  As described above, the blood vessel diameter is measured based on the echo image at rest and the echo image at the time of hyperemia, and the degree of vasodilatation (% display) is calculated based on the measured value. % FMD in the vasodilator response is obtained.

In the above embodiment, the case where% FMD is measured is taken as an example. However, the method and apparatus according to the present invention are not limited to such a case, and the blood vessel diameter is set for other purposes. The present invention can be effectively applied to various cases of measurement.
In the above embodiment, the diameter of the brachial artery was measured as an example. However, the method and apparatus according to the present invention are not limited to such a case. However, the present invention can be effectively applied to the case of measuring the diameter of other blood vessels such as the radial artery, and further to the case of measuring the diameter of blood vessels in other parts such as the legs instead of the arms.

  A blood vessel diameter measuring method and apparatus using an echo according to the present invention is an apparatus that takes an echo image of a predetermined blood vessel of a measurement subject and measures the diameter of the blood vessel based on the echo image. It can be used effectively in the measurement of so-called% FMD (Flow-Mediated Dilatation), which is an indicator of blood flow-dependent vasodilatory reaction that is said to be deeply related to function and arteriosclerosis.

  Thus, it goes without saying that the present invention is not limited to the above-described embodiments, and various changes and improvements can be added without departing from the scope of the invention.

It is explanatory drawing which shows roughly the system configuration | structure of the blood vessel diameter measuring apparatus which concerns on embodiment of this invention. It is a block block diagram which shows schematically the system configuration | structure of the said blood vessel diameter measuring apparatus. It is a block block diagram which shows roughly the structure of the control calculating mechanism of the said blood vessel diameter measuring apparatus. It is explanatory drawing which showed typically the relationship between the attachment direction with respect to the blood vessel of an echo probe, and the echo image imaged. It is explanatory drawing which shows the example which fixes an echo probe via a water bag. It is a perspective view which shows the whole structure of the blood vessel diameter measuring apparatus which concerns on the 1st specific example of the said embodiment. It is a perspective view which expands and shows the upper arm support part of the blood vessel diameter measuring apparatus which concerns on a 1st specific example. FIG. 7 is a cross-sectional explanatory view taken along line Y8-Y8 in FIG. 6. FIG. 7 is a cross-sectional explanatory view taken along line Y9-Y9 in FIG. It is a disassembled perspective view which shows the state by which one part of the blood vessel diameter measuring apparatus which concerns on the 2nd specific example of the said embodiment was decomposed | disassembled. It is an assembly perspective view which shows the assembly state of the blood vessel diameter measuring apparatus which concerns on a 2nd example. It is a disassembled perspective view which shows the state by which a part of blood-vessel diameter measuring apparatus which concerns on the 3rd specific example of the said embodiment was decomposed | disassembled. It is an assembly perspective view which shows the assembly state of the blood vessel diameter measuring apparatus which concerns on a 3rd example. It is a figure which shows an example of the graph which displayed the measurement result of the said blood vessel diameter measuring apparatus as time series data. It is a time chart which shows roughly an example of the measurement procedure of% FMD using the blood vessel diameter measuring apparatus which concerns on this embodiment. It is a time chart which shows roughly an example of the change state of the blood vessel diameter of the brachial artery during measurement. It is a flowchart for demonstrating an example of the said% FMD measurement procedure. It is explanatory drawing which shows typically the template used when detecting the diastole of the blood vessel manually. It is explanatory drawing which shows typically the template used when detecting the diastole of the blood vessel automatically. It is explanatory drawing which shows an image frame layer and the template for automatic detection typically. It is explanatory drawing which shows typically the blood vessel image in an image frame, and the template for automatic detection. It is a graph which shows an example of the luminance distribution in each frame in an image frame layer. It is a diagram for demonstrating the relationship between an xy coordinate system and a polar coordinate system. It is explanatory drawing which shows the curve and outer-frame line displayed by the xy coordinate system. It is explanatory drawing which shows the said curve and outer-frame line which converted and displayed on the polar coordinate system. (A) is explanatory drawing which shows the circle | round | yen and outer frame line displayed by the xy coordinate system, (b) is description which shows the said circle | round | yen and outer frame line converted and displayed on the polar coordinate system which made the center of the circle the origin. FIG. 4C is an explanatory diagram showing the circle and the outer frame line displayed after being converted into a polar coordinate system with the point deviating from the center of the circle as the origin. It is explanatory drawing which shows an example of a blood vessel image typically. It is explanatory drawing which shows the polar coordinate transformation of the said blood vessel image. It is explanatory drawing which shows the display which carried out the polar coordinate conversion of the said blood vessel image. It is explanatory drawing which shows the circular template used for the setting of the virtual center of the blood vessel image. It is explanatory drawing which shows the state which applied the said circular template to the blood vessel image. It is explanatory drawing which shows a circular template and blood vessel image with a variable diameter. It is a diagram for demonstrating automatic recognition of the adventitial edge of a blood vessel image. 3 is a flowchart schematically showing a blood vessel diameter measurement routine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Arm part pressurization mechanism 11 ... Cuff part 12 ... Cuff pressure control part 13 ... Pulse pressure measurement part 14 ... Base part 20 ... Probe fixing mechanism 21 ... Attachment 27 ... Probe fixing tool 28, 68 ... Water bag 30 ... Imaging mechanism DESCRIPTION OF SYMBOLS 31 ... Echo probe 31f ... Ultrasonic emission part 32 ... Echo image processing apparatus 40 ... Control calculating mechanism 41 ... Cuff pressure setting part 42 ... Pulse wave calculating part 43 ... Blood vessel diameter calculating part 44 ... Determination part 45 ... Display processing part 50 ... Display mechanism 51: Monitor display unit 52 ... Printer Af ... Upper arm Au ... Forearm Bv ... Blood vessel Eb ... Blood vessel image F, F1, F2, Fm, Fn ... Image frame Lb ... Blood vessel center line Ms, M1, M2, M3 ... vessel diameter measuring device TP1, TP2, TP3, TP4 ... template UH1, UH2, UH3 ... fixed holding unit Um ... measurement control unit

Claims (36)

In a blood vessel diameter measurement method for capturing an echo image of a predetermined blood vessel of a measurement subject and measuring the diameter of the blood vessel based on the echo image,
A blood vessel diameter measuring method using echoes, which captures an echo image along a plane substantially perpendicular to the center line of the blood vessel. The blood vessel diameter measuring method according to claim 1,
determining the blood vessel center on the echo image of the predetermined blood vessel displayed in the xy coordinate system;
The echo image is displayed after being transformed into a polar coordinate system with the blood vessel center as the origin,
Detecting the edge of the blood vessel based on the echo image of the polar coordinate display,
Obtaining an average diameter of the blood vessel based on the detection data of the edge;
A blood vessel diameter measuring method using an echo characterized by the above. The blood vessel diameter measuring method according to claim 2,
Coordinate conversion to a polar coordinate system is performed by setting the blood vessel wall portion substantially closest to the echo emitting side to 0 degrees and the blood vessel wall portion substantially farthest from the echo emitting side to 180 degrees. A blood vessel diameter measuring method using an echo. In the blood vessel diameter measuring method according to claim 2 or 3,
The echo image of the polar coordinate display is subjected to high frequency noise removal processing using a moving average filter,
Based on the luminance information of the image data of the echo image subjected to the high-frequency noise removal processing, the position where the luminance deviation is larger than a predetermined value is recognized as a blood vessel edge,
For the blood vessel edge of the entire blood vessel wall surface, a position where the position deviation is larger than a certain value is excluded as a misidentified position.
A blood vessel diameter measuring method using an echo characterized by the above. In the blood vessel diameter measuring method according to any one of claims 2 to 4,
The polar image echo image is converted back into the xy coordinate system,
The echo image obtained by the inverse transformation is compared with the echo image of the original xy coordinate display,
Based on the comparison result, the detection data of the blood vessel edge is corrected.
A blood vessel diameter measuring method using an echo characterized by the above. In the blood vessel diameter measuring method according to any one of claims 1 to 5,
Preparing a circular template substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system;
A circular template is approximately superimposed on the blood vessel edge on the echo image,
The center of this overlapped circular template is assumed to be the blood vessel center,
A blood vessel diameter measuring method using an echo characterized by the above. The blood vessel diameter measuring method according to claim 1,
A circular template that substantially corresponds to the blood vessel edge on the echo image displayed in the xy coordinate system and has a variable diameter is prepared.
Adjusting the diameter of the template so that the template approximately overlaps the edge of the blood vessel on the echo image to obtain the diameter of the blood vessel;
A blood vessel diameter measuring method using an echo characterized by the above. In the blood vessel diameter measuring method according to any one of claims 1 to 7,
When estimating the maximum dilated vessel diameter of the above-mentioned blood vessels, a gradual increase of the vessel diameter is estimated by a linear regression method based on the measured values of multiple dilated vessel diameters in the process of hyperemia and the measured value of the reference vessel diameter at rest. A method for measuring a blood vessel diameter using an echo, wherein an estimated value of a dilated blood vessel corresponding to a hyperemia reaction time of 60 seconds is set as a maximum dilated blood vessel. In the blood vessel diameter measuring method according to any one of claims 1 to 8,
Vessel diameter using echo characterized by automatically detecting at least one of diastole and systole of blood vessel based on position information of blood vessel edge obtained from luminance information of image data of echo image Measuring method. In a blood vessel diameter measurement method for capturing an echo image of a predetermined blood vessel of a measurement subject and measuring the diameter of the blood vessel based on the echo image,
When capturing the echo image, the image data of a predetermined number of frames immediately after the echo image is frozen is stored,
Detecting at least one of diastole and systole of the blood vessel based on the predetermined number of frames of image data;
A blood vessel diameter measuring method using an echo characterized by the above. The blood vessel diameter measuring method according to claim 10,
Prepare a template with a size approximating the diameter of the blood vessel on the echo image,
Detecting at least one of the diastolic phase and the systolic phase of the blood vessel by comparing each of the predetermined number of frames of image data with the template as a reference;
A blood vessel diameter measuring method using an echo characterized by the above. The blood vessel diameter measuring method according to claim 11,
A blood vessel diameter measuring method using an echo, wherein at least one of the diastolic phase and the systolic phase of the blood vessel is automatically detected based on luminance information of each image data of the predetermined number of frames. In the blood vessel diameter measuring method according to any one of claims 10 to 12,
The blood vessel diameter measuring method using echoes, wherein the predetermined number of frames corresponds to a time longer than a heartbeat cycle of the measurement subject. In the blood vessel diameter measuring method according to any one of claims 1 to 13,
The cuff pressure is applied to the first part of the arm of the measurement subject and the cuff pressure is released for a predetermined time, and then the cuff pressure is released. The cuff pressure is applied before and after the cuff pressure is released. A method for measuring a blood vessel diameter using an echo, wherein an echo image of a predetermined blood vessel flowing through a second part in the unit is captured and the diameter of the blood vessel is measured based on the echo image. The cuff pressure is applied to the first part of the arm of the measurement subject and the cuff pressure is released for a predetermined time, and then the cuff pressure is released. The cuff pressure is applied before and after the cuff pressure is released. In the blood vessel diameter measuring method for capturing an echo image of a predetermined blood vessel flowing through the second part in the unit and measuring the diameter of the blood vessel based on the echo image,
A blood vessel diameter measuring method using an echo, wherein the ischemic cuff pressure is set based on the highest blood pressure of the subject. The cuff pressure is applied to the first part of the arm of the measurement subject and the cuff pressure is released for a predetermined time, and then the cuff pressure is released. The cuff pressure is applied before and after the cuff pressure is released. In the blood vessel diameter measuring method for capturing an echo image of a predetermined blood vessel flowing through the second part in the unit and measuring the diameter of the blood vessel based on the echo image,
A blood vessel diameter measuring method using an echo, wherein the blood pressure of the measurement subject is measured during the pressure control of the cuff pressure. The blood vessel diameter measuring method according to claim 15 or 16,
The pulse pressure of the measurement subject is detected while increasing the cuff pressure, the cuff pressure at the time when the pulse pressure disappears is detected, and the ischemic cuff pressure is set based on the detected value. Blood vessel diameter measurement method using echo. In the blood vessel diameter measuring method according to any one of claims 14 to 17,
A blood vessel diameter measuring method using an echo, wherein the first part is a forearm and the second part is an upper arm. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Fixing the echo probe of the imaging means to be fixed to a part where the blood vessel of the measurement subject flows in a state where the longitudinal direction of the ultrasonic wave emitting unit is set along a direction substantially orthogonal to the center line of the blood vessel Means,
An apparatus for measuring a blood vessel diameter using an echo, comprising: The blood vessel diameter measuring device according to claim 19,
Display means for displaying the echo image obtained by the imaging means on a screen;
coordinate conversion display means capable of converting the echo image of the predetermined blood vessel displayed in the xy coordinate system into a polar coordinate system having the blood vessel center on the echo image of the xy coordinate display as an origin, and displaying the coordinate conversion display means; Further comprising
The calculation means calculates an average diameter of the blood vessel based on detection data of the blood vessel edge detected based on the echo image of the polar coordinate display.
A blood vessel diameter measuring apparatus using an echo characterized by the above. The blood vessel diameter measuring device according to claim 20,
A moving average filter that performs high-frequency noise removal processing on the echo image of the polar display,
Based on the luminance information of the image data of the echo image subjected to the high frequency noise removal processing, edge recognition means for recognizing a position where the luminance deviation is larger than a predetermined value as a blood vessel edge;
Regarding the blood vessel edge of the entire blood vessel wall surface, a misidentification position exclusion means for eliminating a position where the position deviation is larger than a certain value as a misidentification position;
An apparatus for measuring a blood vessel diameter using an echo, further comprising: The blood vessel diameter measuring device according to claim 20 or 21,
The blood vessel diameter measuring apparatus using echo, wherein the coordinate conversion display means can reversely convert the echo image of the polar coordinate display into an xy coordinate system. In the blood vessel diameter measuring device according to any one of claims 20 to 22,
A circular template displaying a circle substantially corresponding to a blood vessel edge on the echo image displayed in the xy coordinate system and the center of the circle;
Moving means for moving the circular template on the echo image;
An apparatus for measuring a blood vessel diameter using an echo, further comprising: The blood vessel diameter measuring device according to claim 19,
a circular template displaying a circle substantially corresponding to the edge of the blood vessel on the echo image displayed in the xy coordinate system and the center of the circle;
A diameter variable means for changing the diameter of the circular template;
Moving means for moving the circular template on the echo image;
An apparatus for measuring a blood vessel diameter using an echo, further comprising: An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Image data storage means for storing image data of a predetermined number of frames immediately after freezing the echo image when capturing the echo image;
An apparatus for measuring a blood vessel diameter using an echo, comprising: The blood vessel diameter measuring device according to claim 25,
Display means for displaying the echo image obtained by the imaging means on a screen;
A template having a size approximate to the diameter of the blood vessel on the echo image displayed on the display means;
An apparatus for measuring a blood vessel diameter using an echo, further comprising: The blood vessel diameter measuring device according to claim 26,
Vascular diameter measurement using echo, further comprising detection means for automatically detecting at least one of diastole and systole of the blood vessel based on luminance information of each image data of the predetermined number of frames apparatus. In the blood vessel diameter measuring device according to any one of claims 25 to 27,
The blood vessel diameter measuring apparatus using echoes, wherein the predetermined number of frames corresponds to a time longer than a heartbeat cycle of the measurement subject. In the blood vessel diameter measuring device according to any one of claims 19 to 28,
Ischemic means capable of ischeming by applying cuff pressure to the first part of the arm of the subject,
Cuff pressure control means for controlling the cuff pressure so as to release the cuff pressure after applying the cuff pressure to the first part and blocking the blood for a predetermined time;
Fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured;
An imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing before applying the cuff pressure to the first part and after releasing the cuff pressure;
An apparatus for measuring a blood vessel diameter using an echo. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
An ischemic means capable of applying a cuff pressure to the first part of the arm of the subject to be ischemic;
Cuff pressure control means for controlling the cuff pressure so as to release the cuff pressure after applying the cuff pressure to the first part and blocking the blood for a predetermined time;
Fixing means for fixing the echo probe of the imaging means to the second part in the arm of the person to be measured;
An imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing before applying the cuff pressure to the first part and after releasing the cuff pressure;
Ischemic cuff pressure setting means for setting the ischemic cuff pressure based on the highest blood pressure of the measurement subject,
An apparatus for measuring a blood vessel diameter using an echo. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Ischemic means capable of ischeming by applying cuff pressure to the first part of the arm of the subject,
Cuff pressure control means for controlling the cuff pressure so as to release the cuff pressure after applying the cuff pressure to the first part and blocking the blood for a predetermined time;
Fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured;
An imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing before applying the cuff pressure to the first part and after releasing the cuff pressure;
Blood pressure measuring means for measuring the blood pressure of the measurement subject during the control of the cuff pressure;
An apparatus for measuring a blood vessel diameter using an echo. The blood vessel diameter measuring device according to claim 30 or 31,
Further comprising a pulse pressure detecting means for detecting the pulse pressure of the measurement subject when the cuff pressure increases,
The ischemic cuff pressure is set based on the cuff pressure at the time when the pulse pressure disappearance occurs.
A blood vessel diameter measuring apparatus using an echo characterized by the above. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Ischemic means capable of ischeming by applying cuff pressure to the first part of the arm of the subject,
Cuff pressure control means for controlling the cuff pressure so as to release the cuff pressure after applying the cuff pressure to the first part and blocking the blood for a predetermined time;
Fixing means for fixing the echo probe of the imaging means to the second part of the arm of the person to be measured;
Imaging control means for controlling the imaging means so as to capture an echo image of a predetermined blood vessel flowing through the second part at a predetermined timing before applying the cuff pressure to the first part and after releasing the cuff pressure;
The calculation means calculates the degree of expansion of the blood vessel diameter by the blood flow-dependent vasodilation reaction based on the echo image before applying the cuff pressure and the echo image after releasing the cuff pressure,
The calculation means is connected to calculation result display means capable of displaying the expansion degree of the blood vessel diameter in time series.
A blood vessel diameter measuring apparatus using an echo characterized by the above. In the blood vessel diameter measuring device according to any one of claims 29 to 33,
The blood vessel diameter measuring apparatus using echo, wherein the first part is a forearm part and the second part is an upper arm part. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Fixing means for fixing the echo probe of the imaging means to the site where the blood vessel of the measurement subject flows;
Adjusting means capable of adjusting the fixed state of the echo probe in the direction in which the blood vessel flows and the circumferential direction of the blood vessel;
An apparatus for measuring a blood vessel diameter using an echo. An imaging means for imaging an echo image of a predetermined blood vessel of the measurement subject;
Calculation means capable of calculating the diameter of the blood vessel based on the echo image obtained by the imaging means;
Fixing means for fixing the echo probe of the imaging means to the site where the blood vessel of the measurement subject flows;
A water bag interposed between the surface of the part of the subject and the ultrasonic emission surface of the echo probe;
An apparatus for measuring a blood vessel diameter using an echo.

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