JP2001059814A - Noninvasive organism analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the acquisition of accurate organism information by extracting a concentration profile standardizing an image density distribution distributing across the blood vessel of an analysis area, and judging the reliability of the organism information on the basis of the formation characteristics. SOLUTION: A finger 14 is illuminated with the first LED of a light source 11 to image an transmitted image such as the blood vessel image of a skin surface by an imaging part 12. A data processing part 2 sets an analysis area vertically traversing a blood vessel in the image, and the density profile in the vertical direction is prepared in the blood vessel in the analysis area by an imaging density profile extraction function. The base line of the density profile (a straight line showing the background intensity of a blood vessel) is obtained for standardization by a quantification function, a peak height and its half width are found from the standardized density profile, and stored as organism information. The distribution width for reliability judgement is found from the density profile to judge the reliability of the data. After judgement completion, the half width is displayed in a graph on an output part 10 in addition to a reliability judgement result together with the time series change as blood vessel width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-invasive living body analyzing apparatus which irradiates a living body with light, analyzes image information obtained from the living body, and obtains living body information such as the form of the living body and the concentration of a living body component.

[0002]

2. Description of the Related Art As an apparatus for measuring a biological component such as hemoglobin without collecting blood (invasively), there is an apparatus disclosed in International Publication WO 97/24066. In the case of the device, a finger is placed on the detection unit, a transmission image of the finger is obtained, an analysis region (a blood vessel region with good contrast) is set in the image, the analysis region is analyzed, and the blood vessel width, hemoglobin concentration, and the like are determined. It has been calculated.

[0003]

In such a non-invasive bioanalyzer, optical scattering of a living tissue occurs when a blood vessel to be measured exists deep under the skin or when the skin surface is rough. The strength increases and is affected by the measurement results. That is, even if the analysis region orthogonal to the blood vessel is analyzed to obtain the hemoglobin concentration, the extinction of the analysis site is reduced due to the influence of the scattered light of the living tissue, and the value is lower than the original value.

The present inventor has focused on a shape of a concentration profile obtained by analyzing an analysis region orthogonal to a blood vessel in order to solve the above problem, and has completed the present invention by obtaining the following knowledge. That is, since the cross-sectional shape of the blood vessel is substantially circular, the shape of the concentration profile is substantially similar depending on the amount of light absorbed by blood and the diameter of the blood vessel. In practice, light is scattered by the subcutaneous tissue from the blood vessels to the surface of the skin, and the observed image is degraded. For this reason, it was predicted that the observed density profile would be affected by the deterioration of the image and the shape would change. Thus, various experiments were conducted, and it was found that when the blood vessel is located deep from the skin surface, a specific change occurs in the shape of the observed concentration profile. The change is a phenomenon in which the upper part of the density profile becomes thinner and the tail spreads, and is detected as an increase in the ratio of a specific width in the density profile. The present invention
In consideration of such circumstances, a function for determining the reliability of the biological information obtained by the noninvasive biological analyzer is provided, and it is possible to determine whether the output biological information is reliable. It is an object to provide an invasive living body analysis device.

[0005]

A non-invasive living body analyzer according to the present invention includes a light source unit for illuminating a part of a living body, an imaging unit for imaging a part of the illuminated living body, and an imaging unit set in the captured image. A data processing unit that analyzes the analysis region obtained to obtain biological information, an output unit that outputs the obtained biological information, and an operation unit that performs various operations and the like. The image processing apparatus further includes a function of extracting a density profile in which an image density distribution distributed across the image is standardized, and a function of determining reliability of the output biological information based on the morphological characteristics of the profile.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the non-invasive living body analyzer of the present invention, a part of a living body is a living body (preferably a mammal).
It is not a tissue separated from the tissue but a part of the tissue as it is of the living body, and any portion suitable for measurement may be used. In the case of a human, a finger or an earlobe is an example. In the case of a rat or mouse, it may be the tail. The biological information is information on the form (shape, size, number, etc.) of the biological tissue, the concentration of the biological component, and the like. Specifically, it is the size of a blood vessel, the concentration of blood components (for example, hemoglobin, hematocrit, etc.), the concentration ratio of blood components (for example, oxygenation rate of blood, and the like).

[0007] From the viewpoint of convenience of operation and handling, the present apparatus includes a detecting unit (detecting unit, detecting device) for obtaining image information from a living body and an analyzing unit (analyzing unit, analyzing device) for analyzing the obtained image information. It is preferable to be configured separately. Both are connected by information transmission means such as a connector or a cable. The detection unit may include a light source unit and an imaging unit, and the analysis unit may include a data processing unit that analyzes biological information, an output unit, and an operation unit.

The light source section includes a semiconductor laser (LD) and an LE.
A light source such as D or a halogen lamp can be used, and the light from the light source is radiated to the living body directly or via an optical fiber. The wavelength of the light to be irradiated is preferably in the range of 600 to 950 nm, which is transmitted through the living tissue and does not absorb much water.

The image pickup unit includes an optical element such as a lens and a CCD.
And the like. Image information from a living body is generated by an image sensor.

[0010] In order to obtain more preferable image information, it is preferable that the detecting section is provided with a holding member for holding a part of the living body with respect to the optical system. When a part of a living body is, for example, a finger of a human hand, a member that holds the finger between the light source unit and the imaging unit so as to be detachable without pressing the finger can be used as the holding member. For example, it is possible to use a type in which a finger is pinched from both sides by a movable piece.

The analysis unit includes a CPU, a ROM, and a RAM.
And a microcomputer comprising an I / O port and a commercially available personal computer, a data processing unit for analyzing biological information from a captured image, an operating unit for inputting various data and performing various operations, and a biological unit. An output unit for outputting the analysis result of the image information may be provided. As the output unit, a display device such as a CRT or a liquid crystal display or a printing device such as a printer can be used, and as the operation unit, a keyboard, numeric keys, touch keys, or the like can be used.

The data processing unit has a function of extracting a density profile in which an image density distribution distributed across blood vessels in the analysis area is standardized, and based on the morphological characteristics of the profile, the reliability of the output biological information is determined. It has a function to determine gender. This makes it possible to determine that the reliability of the obtained biological information is low, for example, when the blood vessel to be measured exists deep under the skin or when the surface of the skin is rough. That is, by determining the reliability of the obtained biological information, the measurer can select incorrect biological information, and can obtain accurate biological information by re-measurement or the like.

The function of determining the reliability of the biological information is as follows:
It is practical to calculate a feature quantity representing a morphological feature of a standardized density profile and to compare the feature quantity with a reference feature quantity.

Further, the feature quantity representing the morphological feature is
The distribution width is preferably a standardized concentration profile.

[0015]

FIG. 1 is an external view of an embodiment of a non-invasive living body analyzing apparatus according to the present invention, in which a mouse-like detecting section 1 is mounted on a mounting section 4 of an analyzing section 3 of a notebook type personal computer. Is shown. FIG. 2 is an overall block diagram functionally representing the noninvasive living body analyzer of FIG.

The detection unit 1 mounted on the mounting unit 3 is electrically and mechanically connected to a connector 7 on the detection unit 1 side and a connector 8 on the analysis unit 3 side. In order to obtain a degree of freedom in measurement and handling, the detection unit 1 is detached from the mounting unit 4 of the analysis unit 3, and the detection unit 1 and the analysis unit 3 are connected with a connection cord with a connector.
It is also possible to connect and use.

The detecting unit 1 includes an arm 5 and a housing 6 that can rotate with respect to the arm 5. A light source unit 11 is built inside the arm 5, and an imaging unit 12 is installed inside the housing 6 facing the arm 5. Built-in. Holding a human finger 14 between the arm 5 and the housing 6,
Light is applied to the back of the finger at the joint, and a transmitted light image is taken from the abdomen of the finger. The finger is elastically clamped from both sides of the finger.

The light source unit 11 includes a plurality of LEDs having different wavelengths.
Comprising a light emitting element having L3989 (manufactured by Hamamatsu Photonics KK) having a center wavelength of 830 nm and a half-value width of 40 nm is used as the first LED, and L25656 (manufactured by Ibid.) Having a center wavelength of 890 nm and a half-value width of 50 nm is used as the second LED. . When measuring the blood vessel width, the first LE
Only D is turned on, and the first and second LEDs are turned on when measuring the blood component concentration.

The analysis unit 3 comprises a data processing unit 2, an output unit (liquid crystal monitor) 10, and an operation unit (a plurality of keys) 9.
The analysis unit 3 is provided with an insertion slot 13 for a floppy disk as an external storage medium, and can externally store measurement information and the like.

FIG. 2 is an overall block diagram of the non-invasive living body analyzer of this embodiment. The entity of the data processing unit 2 of the analysis unit 3 is a computer having a CPU and a memory, and calculates the density distribution of the blood vessel portion in the analysis area in the captured image of the finger 14 obtained by the imaging unit 12 of the detection unit 1. A density profile extraction function to extract as a profile, a function to create a standardized density profile from the extracted density profile, a function to determine the reliability of biological information output based on the morphological characteristics of the standardized density profile, It has a quantification function for quantifying the morphological features of the standardized concentration profile, and a calculation function for calculating biological information such as blood vessel size and blood component concentration based on the quantified features.

Referring to the flowcharts of FIGS.
The procedure for measuring the blood vessel width will be specifically described. FIG. 4 is a flowchart for calculating a distribution width for reliability determination from a standardized density profile and determining reliability. Here, the same person's finger is imaged a plurality of times over time using one wavelength, and the change over time in the blood vessel width at the same blood vessel site is measured.

First, the finger 14 is illuminated and imaged by the first LED (first wavelength), and a transmission image combining blood vessel (vein) images existing on the skin surface of the finger 14 is obtained (step S).
1). FIG. 5 schematically shows the obtained transmission image.
An analysis region set so that a region indicated by a rectangle vertically crosses a blood vessel is shown.

Next, the data processor 2 performs the following processing. An analysis area is set in the obtained captured image (step S2), and a density profile in a direction perpendicular to the blood vessel (FIG. 5) is created in the set analysis area by the imaging density profile extraction function (step S3).

The baseline of the density profile is obtained by the quantification function and standardized (step S4). Here, the baseline is a straight line obtained by the least square method from the concentration profile of the part other than the blood vessel,
The luminance of the background of the blood vessel portion is shown. Further, the density profile is normalized by dividing it by the baseline and further logarithmized, whereby a standardized density profile (FIG. 6) that does not depend on the amount of incident light or the gradient of the background luminance can be obtained.

The distribution width (half width) w1 at the peak heights h1 and (1/2) h1 as the morphological features is calculated from the standardized density profile (step S5), and the biological information is obtained and stored.

A distribution width for reliability determination is obtained from the standardized density profile to determine data reliability (step S6). As shown in FIG. 4, a parameter for determining reliability from a standardized density profile (20
%) Distribution width W20 at h1 and distribution width W71 at (71%) h1 are determined (step S11), and W20 / W
71 is calculated (step S12). And W20 /
If W71 ≧ 2.20, the output biological information is determined to be unreliable (steps S13 and S14), and W20 /
If W71 <2.20, the output biological information is determined to be reliable (steps S13 and S15). The judgment result is displayed together as a mark or a message when outputting the biological information. The widths W20 and W71 of the standardized density profile are shown by arrows in FIG.

Here, FIG. 9 shows a normal normalized profile, and FIG. 10 shows a normalized concentration profile obtained by measuring a deep blood vessel region. It can be seen that the normalized density profile of the deep blood vessel is thinner at the top of the profile, relatively wider at the skirt, and lower at the height of h1 than the normal normalized density profile. At this time, the normalized density profile W20 / W20 /
W71 = 1.98, there is no problem in reliability, and W20 / W71 = 2.25 in the standardized density profile of FIG.
It turns out that there is a problem in reliability.

When the reliability is determined, the half width w1 obtained from the standardized density profile is calculated as the blood vessel width (step S7).

When the measurement is completed, a graph or a table representing the time-series change is created from the calculated blood vessel width and displayed (steps S8 and S9). At this time, the output biological information is displayed with the reliability determination result appended thereto. For example, if there is no reliability, a low reliability mark or message is displayed. During or after the measurement, a message indicating that the measurement site is not appropriate (for example, measurement of a deep subcutaneous blood vessel) may be displayed, and a message may be displayed so that the measurement site is changed and the measurement is performed again.

Although an example of measuring the blood vessel width using one wavelength has been described above, the hemoglobin concentration can be measured using a plurality of wavelengths. That is, the hemoglobin concentration can be calculated from the form of the standardized concentration profile obtained for each wavelength. See International Publication WO
Reference can be made to Japanese Patent Application Laid-Open No. 97/24066 or the like, and a description thereof is omitted here.

FIG. 11 shows the output unit 10 (liquid crystal display).
5 is a display example. The display screen includes a graph display area 51, a measurement data display area 52, a measurement information area 53, a message area 54, a data display format switching area 55, and a command area 5.
6 is provided.

In the graph display area 51, the measured hemoglobin concentration HGB and blood vessel width, which are biological information, are displayed as a time-series graph.

The measurement data display area 52 displays measurement data at the time of measurement on the graph. In the measurement information area 53, measurement person information such as a measurement number, a measurement person name, a date of birth, and gender is displayed. The message area 54 displays a message indicating the state of the system and a message urging the measurer to operate.

In the data display format switching area 55, icons for switching the data display format (graph, data list, captured image) are displayed. When displaying the captured image, it is preferable to also indicate the analysis area.

In the command area 56, icons for executing various commands are displayed. By selecting an icon, measurement data recording to a PC card, file deletion setting, data transfer, printing, maintenance, and the like can be executed.

The graph shown in the graph area 51 of FIG. 11 shows the hemoglobin HGB, blood vessel width, and oxygenation rate VOI measured for the same subject before daily exercise.
7 is a time series graph of a time trial result (data is input for each measurement) separately input. In addition, the bar (indicated by a broken line) indicating the measurement point on the graph of the time-series data can be moved with the “cursor” key, and the corresponding measurement date,
The measurement time, the measurement result, and the comment can be displayed in the display area 52.

[0037]

According to the present invention, it is possible to extract a density profile standardizing an image density distribution distributed across blood vessels in a captured image, and determine the reliability of the output biological information based on the morphological characteristics of the profile. By determining whether or not the obtained biological information is reliable, the measurer can select incorrect biological information, and can obtain accurate biological information by re-measurement or the like.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment of the present invention.

FIG. 2 is a block diagram of an embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 5 is a schematic diagram of an image obtained by an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a density profile.

FIG. 7 is an explanatory diagram showing a standardized density profile.

FIG. 8 is an explanatory diagram showing a standardized density profile.

FIG. 9 is an explanatory diagram showing a standardized density profile.

FIG. 10 is an explanatory diagram showing a standardized density profile.

FIG. 11 is an explanatory diagram showing a display example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Detection part 2 Data processing part 3 Analysis part 9 Operation part 10 Output part 11 Light source part 12 Imaging part 14 Human finger

Claims (3)

[Claims] 1. A light source unit for illuminating a part of a living body, an imaging unit for imaging a part of the illuminated living body, and a data processing unit for analyzing an analysis region set in the captured image to obtain biological information. An output unit for outputting the obtained biological information, and an operation unit for performing various operations, etc., and the data processing unit performs a density profile standardizing an image density distribution distributed across blood vessels in the analysis region. A non-invasive bioanalytical apparatus having a function of extracting and a function of judging the reliability of the outputted biological information based on the morphological characteristics of the profile. 2. The function of determining the reliability of biological information includes a function of calculating a feature value representing a morphological feature of a standardized density profile, and comparing the feature value with a reference feature value. The non-invasive living body analyzer according to claim 1, wherein: 3. The non-invasive bioanalytical apparatus according to claim 2, wherein the feature quantity representing the morphological feature is a distribution width of a standardized concentration profile.