KR20110022132A - Pulse wave measuring apparatus using laser speckle image and pulse wave measuring method using this apparatus - Google Patents

Abstract

PURPOSE: A device and a method for measuring a pulse wave are provided to obtain the minimum blood pressure, the maximum blood pressure, an average blood pressure, and a pulse wave form of a subject by obtaining a laser speckle image in real time. CONSTITUTION: A pressing unit(200) fixes a wrist of a subject and presses a part of the wrist. A speckle image obtaining unit(100) obtains speckle image information by emitting one or more laser beams to the fixed wrist of a subject through a laser speckle interferometry. A central process unit obtains and reveals pulse wave form by receiving the speckle image information obtained by the speckle image obtaining unit in real time.

Description

Pulse wave measuring apparatus using laser speckle image and Pulse wave measuring method using this apparatus

The present invention relates to a device for measuring the pulse wave and a method for measuring the pulse wave using the same, and more particularly, through the use of an optical device to finely vary the partial coherent light of the measurement site while fixing and pressing the wrist region of the measurement target The present invention relates to a pulse wave measuring device using laser sparkle imaging and a pulse wave measuring method using the laser sparkle imaging, which can measure blood pressure in real time by using laser sparkle imaging to measure peak blood pressure, minimum blood pressure, average blood pressure, and pulse wave waveform.

In general, there are invasive and non-invasive methods of measuring blood pressure of a subject, and a catheter for measuring blood pressure is inserted into a peripheral artery to directly measure blood pressure. This method is a representative example, but this method is a risk of arterial bleeding and should be invaded, there is a problem that can not be used frequently and conveniently for the measurement of the state of health.

On the other hand, non-invasive methods include auscultation, oscillometry and tonometry.

The auscultation method and the oscilloscope method use an inflatable brachial cuff that presses the peripheral artery of the subject. You will be able to know your heart relaxation pressure. In addition, the oscillometric method can measure the average pressure of the subject's blood pressure by measuring the actual pressure change in the cuff as the cuff contracts.

However, these two methods have a disadvantage in that the cuff needs to be inflated and contracted alternately, and thus the pressure value is intermittently measured and the actual blood pressure waveform of the subject cannot be continuously monitored.

Arterial tonometry eliminates the effects of vascular wall tension by compressing the artery to the extent that a flat surface is formed in a superficial artery with a bone support such as the radial artery. Sensors can detect changes in arterial pressure.

The arterial tonometry method locates the sensor on the artery and pressurizes the artery while the sensor detects the change in the arterial pressure, and it is difficult to find the exact location of the artery. Has the inconvenience of resetting it.

An object of the present invention is to provide a pulse wave measuring apparatus and a pulse wave measuring method capable of accurately and conveniently measuring a health state without a user feeling uncomfortable.

In addition, it is to solve the problem that it is difficult to determine the exact location of the arteries of the measurement object in the tonometry method, and to solve the inconvenience of repositioning the sensor according to the variation of the measurement site.

Furthermore, to provide pulse wave measuring device and pulse wave measuring method that can measure pulse wave of subject in real time and provide various information such as minimum blood pressure, maximum blood pressure, average blood pressure, pulse wave waveform, and augmented index (AI) do.

The present invention to achieve the above technical problem, the pressing means for pressing a predetermined portion of the wrist while fixing the wrist of the measurement target; Spackle image acquisition means for emitting at least one laser light to the fixed wrist of the subject to obtain the speckle image information using laser speckle interferometry; And a central processing means for receiving pulse wave image information obtained from the speckle image obtaining means in real time and obtaining and displaying the pulse wave waveform data.

Preferably, the speckle image acquisition means, the laser generation unit for emitting a laser light to the wrist of the measurement target fixed to the pressing means; And an irradiation unit configured to receive a reflected light from the wrist of the measurement target to obtain image information.

The speckle imaging means further includes a beam combiner for synchronizing the spatially coaxially and spatially synchronizing the laser light emitted from the laser generator with the reflected light from the wrist of the subject, The irradiation unit may obtain light information coupled through the beam combiner.

Preferably, the pressing means, the cradle for positioning the wrist of the measurement target; A compression band mounted on the cradle to wrap and fix the wrist of the measurement target and at least a portion thereof is transparent; A pneumatic tube for applying pressure to a predetermined portion of the compression band by using the pressure of the injected air; And it may include a pump motor for controlling the pressure of the air of the pneumatic tube.

More preferably, the central processing means comprises: a storage unit for storing the speed change of the blood flow from the speckle image information and the speckle image information obtained from the speckle image acquisition means; A processing unit for calculating a speed of blood flow from the speckle image information and calculating maximum blood pressure, minimum blood pressure, average blood pressure, and pulse wave waveform data based on a change in the speed of blood flow; A display unit configured to display the speckle image information, the highest blood pressure, the lowest blood pressure, the average blood pressure, the pulse wave waveform data, and the blood vessel thickness; And it may include a control unit for controlling the pressing means and the speckle image acquisition means.

Furthermore, the spackle image acquisition means is located at a distance spaced above the pressing means, and may further include a height adjusting means for adjusting the height of the spackle image acquisition means is located from the pressing means.

In another aspect, the present invention provides a method for measuring the pulse wave with a pulse wave measuring apparatus using laser sparkle imaging, comprising the steps of: a) fixing the wrist of the subject to be measured, and determining the measurement site of the wrist; b) emitting laser light while applying pressure to the wrist, and irradiating a speckle pattern according to scattering and interference of the laser light on the wrist to obtain a laser sparkle image; And c) acquiring pulse wave data based on the obtained laser sparkle image. The pulse wave is measured by a pulse wave measuring apparatus using laser sparkle imaging.

Preferably, the step a) comprises: holding the wrist of the subject to be measured and applying pressure to a portion of the wrist in the absence of flow of the wrist; Emitting laser light to the wrist and irradiating a speckle pattern according to scattering and interference of the laser light to obtain a laser sparkle image; Extracting a blood vessel region based on the obtained laser sparkle image; And determining a measurement site among the blood vessel regions.

In the determining of the measurement site, a point where the blood flow is fastest in the blood vessel region on the obtained laser sparkle image may be selected as the measurement site.

Preferably the step b) comprises the steps of: emitting a laser beam at the measurement site while varying the pressure applied to the wrist; Obtaining a laser sparkle image by irradiating a scatterle pattern according to scattering and interference of the laser light in the wrist; And storing the obtained laser sparkle image.

In addition, the step c), by measuring the speed of the blood flow based on the laser sparkle image recording the speed change of the blood flow; And calculating the highest blood pressure, the lowest blood pressure, the average blood pressure, and the pulse wave waveform data based on the recorded speed change of the blood flow.

Furthermore, step c) may further include calculating an AI index based on the pulse wave waveform data.

According to the present invention, in order to solve the difficulty of accurately estimating the position of the blood vessel by measuring the pulse wave using the tonometry method, it is possible to find the exact blood vessel using the laser spackle image.

In addition, it is possible to acquire a variety of information, such as the minimum blood pressure, the highest blood pressure, the average blood pressure, the pulse wave waveform and the thickness of blood vessels of the subject to be measured based on the laser spackle image in real time. You can also calculate the index.

In order to explain the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, the following describes exemplary embodiments of the present invention and looks at it with reference.

The present invention provides a pulse wave measuring apparatus using a laser spackle image, which is an image of a power intensity distribution generated by interference of partially coherent light, which fluctuates in time and space, and a pulse wave measuring method using the apparatus.

Laser speckle interferometry is a technique that can be used for deformation, stress analysis, non-destructive inspection or vibration analysis of objects through non-contact high resolution with only the change of optical interferometer using laser.

When the coherent light such as laser light is irradiated onto the surface of the object, the laser scatters and interferes with the roughness of the surface of the object to form a spot-like pattern, which is called a sparkle pattern. The speckle pattern includes surface deformation information of the object, and the surface deformation information of the object can be obtained by recording and processing the speckle pattern.

In other words, when the laser is irradiated to the object before deformation of the object, a sparkle pattern is formed, and the sparkle pattern having the surface shape information of the object is recorded by the image processing apparatus. The cleat pattern changes with the surface deformation of the object, and the speckle pattern after the deformation of the object is recorded in the image processing apparatus. A fringe pattern can be obtained by subtracting the recorded sparkle pattern before and after the two deformations in real time, and the stripe spacing of the fringe pattern is related to the deformation of the object. In other words, by properly processing the gaps of the stripes, deformation information before and after deformation of the object can be obtained.

The pulse wave measuring apparatus according to the present invention measures the pulse wave by using such a laser spackle pattern, Figure 1 shows a schematic cross-sectional view of an embodiment of the pulse wave measuring apparatus according to the present invention.

The pulse wave measuring apparatus according to the present invention is schematically composed of a speckle image acquisition means 100, a pressing means 200, a central processing means 300, and the like.

The pressing means 200 pressurizes a predetermined portion of the wrist while fixing the wrist of the measurement target, and wraps and fixes the wrist of the measurement target with the compression band 230 and uses the pressure of air injected into the pneumatic tube 250. By pressing a predetermined portion of the compression band 230 to press a predetermined portion of the wrist of the subject.

In this case, the compression band 230 may form a portion where the laser light is incident and the reflected light is emitted in order to obtain a speckle pattern, or may form the entire transparent portion to transmit the laser light and the reflected light.

Compression means 200 includes a pump motor 270 for injecting or bleeding air into the pneumatic tube 250, the pump motor 270 by pneumatic by measuring the pneumatic pressure of the pneumatic tube 250 through a pressure gauge 280 The pressure of the air of the tube 250 may be adjusted.

The speckle image obtaining means 100 emits at least one laser light to the fixed wrist of the subject to obtain the speckle image information by using laser speckle interferometry.

The central processing unit 300 receives the sparkle image information obtained from the sparkle image acquisition means 100 to acquire and display the pulse wave waveform data, and furthermore, the compression means 200 and the sparkle image acquisition means 100 are provided. Although not shown in FIG. 1, the central processing unit 300 may include a storage unit, a processing unit, a display unit, a controller, and the like.

Here, the storage unit stores the speed change of the blood flow from the speckle image information and the speckle image information obtained from the speckle image acquisition means, the processing unit calculates the speed of the blood flow from the speckle image information and the speed of the blood flow The maximum blood pressure, the lowest blood pressure, the average blood pressure, and the pulse wave waveform data are calculated based on the change, and the display unit displays the speckle image information, the maximum blood pressure, the minimum blood pressure, the average blood pressure, the pulse wave waveform data, and the like, and the control unit is a compression means. 200 and the speckle image acquisition means 100 and the like.

Furthermore, the spackle image acquisition means 100 is located at a distance away from the top of the compression means 200, and the height adjustment means for adjusting the height at which the spackle image acquisition means 100 is located from the compression means 200. 400 may be provided.

In obtaining the sparkle image as described above, since a lot of noise is generated even in the minute movement of the wrist of the measurement subject, the present invention adjusts the pressure applied to the wrist in a state where the wrist of the measurement subject is fixed to block the generation of noise. 2 shows an embodiment of the pressing means for fixing the wrist of the measurement subject according to the invention and Figure 3 shows an embodiment in which the wrist of the measurement subject is fixed.

2 and 3, in order to block the movement of the wrist of the subject to be measured, the pressing means 200 is provided with a cradle 210 for fixing while positioning the wrist of the subject to be measured and pressed against the cradle 210. Band 230 is mounted. As such, while placing the wrist of the subject to be measured on the holder 210, the wrist band of the subject is surrounded by the compression band 230 to block minute movements of the wrist of the subject.

4 shows the operation of the pulse wave measuring apparatus according to the present invention.

In the present invention, by using the tonometry method while compressing the artery of the wrist portion of the subject to be measured by the compression means 200 to obtain a laser spackle image through the sparkle image acquisition means 100 to the blood flow according to the change in the arterial pressure The change in speed is measured. In particular, in order to accurately estimate the center of blood vessels, it is important to measure minute pulse waves. For this purpose, the laser spackle image is used in the present invention.

The speckle image acquisition means 100 generates a laser light and emits the laser light to the wrist of the measurement target fixed to the compression means 200, and the irradiation unit 130 receives the reflected light from the wrist of the measurement target. In this case, the irradiation unit 130 includes a CCD detector (CCD detector) composed of a CCD (Charge-Coupled Device) for obtaining image information from the reflected light, and also the laser light emitted from the laser generating unit 110 and the subject Is provided with a beam combiner 150 for temporally synchronizing and spatially matching the reflected light from the wrist of the wrist, and the irradiator 130 combines the optical information coupled through the beam combiner 150. An image can be obtained.

As shown in FIG. 4, the wrist of the measurement subject is placed on the compression band 230 of the compression means 200, and the wrist is pressed on the wrist of the measurement subject while pressing the wrist through the pneumatic tube 250. The blood flow velocity of the artery A is measured, and the laser generator 110 emits laser light from the wrist of the subject to be measured, and the irradiation unit 130 receives the reflected light from the wrist, and the irradiation unit 130 uses a CCD detector. Show the sparkle image as a dimensional image.

Hereinafter, a method of measuring pulse waves using a pulse wave measuring apparatus using laser spackle imaging according to the present invention will be described.

5 shows a schematic flowchart of a method for measuring a pulse wave according to the present invention.

In order to use the tonometry method, the wrist of the subject to be measured is fixed by the compression means 200 and the wrist is compressed to have no flow on the wrist (S110). Since it occurs a lot, first of all to fix the movement of the wrist.

In addition, the laser light is emitted to a predetermined portion of the wrist fixed through the sparkle imaging means 100, and the laser light is received from the scattering and interference of the laser light on the wrist to obtain a laser spackle image (S120). Shows an embodiment of the laser spackle image thus obtained.

A plurality of blood vessels are present on the laser spackle image obtained as described above. In order to find blood vessels in the obtained laser spackle image, blood vessel regions are extracted from the laser spackle image as shown in the embodiment of FIG. 7 (S130). In step S140, a measurement site is determined by selecting a point where blood flow is fastest among the extracted blood vessel regions. In this case, the user may arbitrarily select a blood vessel region and a measurement site, but it is preferable to automatically extract the blood vessel through the central processing unit 300 to estimate the exact highest peak point. 8 shows an embodiment in which a measurement site is selected on the obtained laser spackle image.

When the measurement site is determined as described above, while the pressure applied to the wrist by the compression means 200 emits the laser light through the speckle image acquisition means 100 (S210) to irradiate the speckle pattern in real time, and the laser spackle image It is obtained (S220).

In addition, the central processing unit 300 stores the obtained laser sparkle image in order to prepare for the change before and after the change (S230) and measures the blood flow rate based on the change of the laser sparkle image (S310) to measure the change in the measured blood flow rate. Record (S320).

The lowest blood pressure, the highest blood pressure, the average blood pressure, etc. of the subject to be measured may be calculated based on the change in the blood flow rate obtained as described above, and the pulse wave waveform data is calculated based on the calculated data (S330). The graph of the pulse wave waveform computed by the method of measuring the pulse wave by the following is shown.

Furthermore, the pulse wave amplification coefficient (AI index) can be calculated based on the measured pulse wave waveform data, and the pulse wave amplification coefficient is calculated as a ratio of the frequency (a) and the reflected wave (b) in the pulse wave of the radial artery measured in the graph of FIG. 9. (AI index) can be obtained from Equation 1 below.

[식 1]

[Equation 1]

As shown in FIG. 10, the pulse wave amplification coefficient (AI index) of the subject may be calculated, and the thickness of the blood vessel may also be measured based on the blood vessel region on the obtained laser spackle image.

As described above, in the present invention, the pulse wave is measured using the tonometry method. In order to solve the difficulty of accurately estimating the position of the blood vessel, the center portion of the blood vessel can be found using the laser spackle image.

In addition, the present invention can obtain a variety of information, such as the lowest blood pressure, the highest blood pressure, the average blood pressure, the pulse wave waveform and the thickness of the blood vessel of the subject to be measured based on the laser spackle image in real time, and further measured by the various information obtained The subject's pulse wave amplification coefficient (AI index) can also be calculated.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the technical idea of the present invention but to explain, and the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 shows a schematic cross-sectional view of an embodiment of a pulse wave measuring apparatus according to the present invention,

Figure 2 shows an embodiment of the pressing means for fixing the wrist of the measurement subject according to the present invention,

3 illustrates an embodiment in which a wrist of a measurement subject is fixed;

4 is a cross-sectional view showing the operation of the pulse wave measuring apparatus according to the present invention,

5 shows a schematic flowchart of a method for measuring a pulse wave according to the present invention,

6 shows an embodiment of a laser spackle image obtained by the present invention,

7 illustrates an embodiment in which a blood vessel region is extracted from a laser spackle image obtained by the present invention.

8 shows an embodiment in which a measurement site is selected on a laser spackle image obtained in the present invention.

9 shows a graph of the pulse wave waveform calculated by the method for measuring the pulse wave according to the present invention,

10 shows the AI index of the measurement subject calculated by the present invention.

<Description of Major Symbols in Drawing>

100: means for acquiring a speckle image, 110: laser generating unit,

130: irradiation unit, 150: beam combiner,

200: pressing means, 210: holder,

230: compression band, 250: pneumatic tube,

270: pump motor, 280: pressure gauge,

300: central processing means, 400: height adjusting means.

Claims (12)

Compression means for pressing a predetermined portion of the wrist while fixing the wrist of the measurement target; Spackle image acquisition means for emitting at least one laser light to the fixed wrist of the subject to obtain the speckle image information using laser speckle interferometry; And And a central processing means for receiving pulse wave image information obtained from the speckle image obtaining means in real time to acquire and display pulse wave waveform data. The method of claim 1, The speckle image acquisition means, A laser generator for emitting laser light to a wrist of a measurement subject fixed to the pressing means; And And a radiation unit configured to receive a reflected light from the wrist of the subject to obtain image information. The method of claim 2, The speckle image means, A beam combiner for synchronizing the laser light emitted from the laser generation unit with the reflected light from the wrist of the measurement target in time and matching spatially and coaxially, The irradiator, pulse wave measuring apparatus characterized in that for obtaining the optical information coupled through the beam combiner. The method of claim 1, The pressing means, A cradle for positioning the wrist of the subject; A compression band mounted on the cradle to wrap and fix the wrist of the measurement target and at least a portion thereof is transparent; A pneumatic tube for applying pressure to a predetermined portion of the compression band by using the pressure of the injected air; And Pulse wave measuring device comprising a pump motor for controlling the pressure of the air of the pneumatic tube. The method of claim 1, The central processing means, A storage unit storing the speed change of the blood flow from the speckle image information acquired from the speckle image obtaining means and the speckle image information; A processing unit for calculating a velocity of blood flow from the speckle image information and calculating a maximum blood pressure, a minimum blood pressure, an average blood pressure, pulse wave waveform data, and a blood vessel thickness based on a change in the speed of blood flow; A display unit configured to display the speckle image information, the highest blood pressure, the lowest blood pressure, the average blood pressure, and the pulse wave waveform data; And And a control unit for controlling the compression means and the speckle image acquisition means. The method of claim 1, The spackle image acquisition means is located at a distance spaced above the compression means, And a height adjusting means for adjusting a height at which the spackle image obtaining means is located from the pressing means. In the pulse wave measuring method using a pulse wave measuring apparatus using laser sparkle imaging, a) fixing a wrist of the subject to be measured and determining a measurement site of the wrist; b) emitting laser light while applying pressure to the wrist, and obtaining a laser sparkle image by irradiating a speckle pattern according to scattering and interference of the laser light in the wrist; And and c) acquiring data of a pulse wave waveform based on the obtained laser sparkle image. The method of claim 7, wherein Step a) is Fixing a wrist of a subject to be measured and applying pressure to a portion of the wrist in a state where there is no flow of the wrist; Emitting laser light to the wrist and irradiating a speckle pattern according to scattering and interference of the laser light to obtain a laser sparkle image; Extracting a blood vessel region based on the obtained laser sparkle image; And Method for measuring the pulse wave with the pulse wave measuring apparatus using laser spackle imaging, characterized in that it comprises the step of determining the measurement site in the blood vessel region. The method of claim 8, In the determining of the measurement site, a pulse wave measurement method using a pulse wave measuring apparatus using laser spackle imaging, wherein a point where blood flow is fastest in a blood vessel region on the obtained laser sparkle image is selected as a measurement site. . The method of claim 7, wherein B), Emitting laser light to the measurement site while varying the pressure applied to the wrist; Irradiating a speckle pattern according to scattering and interference of the laser light in the wrist to obtain a laser speckle image; And And storing a pulse wave image obtained by the pulse wave measuring apparatus. The method of claim 7, wherein C), Measuring the speed of blood flow based on the laser sparkle image to record a speed change of blood flow; And And calculating the peak blood pressure, the lowest blood pressure, the average blood pressure, and the pulse wave waveform data based on the recorded change in the velocity of the blood flow. The method of claim 11, And calculating a pulse wave amplification coefficient (AI index) based on the pulse wave waveform data.

Images