This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. JP2007-336392 filed on Dec. 27, 2007, the entire content of which is hereby incorporated by reference.
The present invention relates to a noninvasive living body measuring device and a noninvasive living body measuring method.
In the past, for example, a noninvasive living body measuring device disclosed in U.S. Pat. No. 7,280,860 has been known as a device for measuring components of a blood by imaging a living body with the use of image pick-up means and analyzing a blood vessel in a living body image. The noninvasive living body measuring device measures blood components from the image obtained by illuminating a wrist including a blood vessel (vein) with a light source and imaging the illuminated wrist.
The noninvasive living body measuring device includes a detection section which is mounted on an arm of a person and an analysis section which is connected to the detection section. The detection section includes a support base, a rotary base which is vertically inserted into a central opening of the support base so as to be rotatably supported, a housing which is mounted on a central opening of the rotary base, and a pair of holding pieces for fixing the support base to a wrist. The support base has a circular opening at the bottom thereof, and a light source section composed of 6 light emitting diodes disposed concentrically with the opening is provided around the opening. In the housing, an image pick-up section is housed to image an image pick-up area on a living body illuminated by the light source section.
When the noninvasive living body measuring device performs a measurement operation, the detection section is mounted on the wrist, and the housing is rotated to adjust a position of the image pick-up area while a monitor image of an output section provided in the analysis section is observed.
However, the device described in U.S. Pat. No. 7,280,860 is constituted so that the housing including the image pick-up section can be rotated but a position of the image pick-up section is determined by the position in which the detection section is fixed to the wrist. Consequently, once the detection section is fixed to the arm, the movement of only the image pick-up section cannot be performed. Accordingly, for example, when the image pick-up section is not disposed at a position in which a measurement target blood vessel can be imaged, it is required to move the image pick-up section together with a body of the device to change the position of the image pick-up section and the operation thereof is complicated.
A first aspect of the invention is a noninvasive living body measuring device comprising: an image pick-up section for imaging a living body; a device body comprising an analysis section for acquiring biological information by analyzing an image obtained by an image pick-up operation of the image pick-up section; a fixing section for fixing the device body to a living body; and an image pick-up section position adjusting section for adjusting a position of the image pick-up section on a living body in a state in which the device body is fixed to a living body.
A second aspect of the invention is a noninvasive living body measuring method comprising the steps of: fixing to an arm a device body including an image pick-up section for imaging a living body and an analysis section for acquiring biological information by analyzing an image obtained by the image pick-up operation of the image pick-up section; adjusting a position of the image pick-up section on palmar side of a wrist of the arm; imaging a site of the living body corresponding to the position adjusted in the adjusting step by the image pick-up section; and acquiring a biological information by analyzing with the analysis section an image obtained in the imaging step.
Hereinafter, embodiments of a sample analyzer of the invention will be described in detail with reference to the accompanying drawings.
Hereinafter, embodiments of a noninvasive living body measuring device according to the invention will be described in detail with reference to the accompanying drawings.
The device body 2 includes the control section 10 for analyzing a living body image picked up by the image pick-up section 6, the display section 8 for displaying the living body image picked up by the image pick-up section 6, an index indicating the position adjustment of the image pick-up section 6, a measurement result or the like, and the operation section 9 for operating the device 1.
Further, the device body 2 is provided with a first fixing member 25. The first fixing member 25 holds the arm of the user with a second fixing member 43 provided in the slide member 4 to fix the device body 2 to the arm. The receiving section 5 is connected to the first fixing member 25 via the image pick-up section position adjusting section 7 and the image pick-up section 6 is received in the receiving section 5. The receiving section 5 is provided with an image pick-up section rotating section 55 for rotating the image pick-up section 6.
The slide member 4 includes a frame 41 which is provided so as to surround a side of the device body 2, a connection section 42, and the second fixing member 43 which is connected to the frame 41 by the connection section 42, and is supported slidably in a Y1 direction and a Y2 direction by the device body 2. The second fixing member 43 is provided with the separation preventing member 11 for preventing the separation of the arm of the user when the device body 2 is fixed to the arm.
The device body 2 includes a liquid crystal cover 23, an upper housing 21, a battery cover 24, a lower housing 22, the display section 8, the operation section 9 including an operation key 91 and a switch substrate 92, the control section 10, and a battery 13.
The liquid crystal cover 23 includes a transparent member having a substantially square shape and is used to protect a display plane of the display section 8 received in the device body 2.
The upper housing 21 is a member which is attached to the lower housing 22 to constitute a housing of the device body 2. The upper surface of the upper housing 21 is provided with a depressed section 21a to which the liquid crystal cover 23 is fitted. At the center of the depressed section 21a, a first opening 21b corresponding to the display plane of the display section 8 attached to the lower side is provided. In addition, near the depressed section 21a, a second opening 21c to which the operation key 91 and the switch substrate 92 are fitted is provided.
The operation section 9 includes the operation key 91 and the switch substrate 92. The operation key 91 includes a “start/completion” key 91a and “measurement/record” key 91b and is electrically connected to the switch substrate 92 corresponding to the keys. The switch substrate 92 is further electrically connected to the control section 10 to be described later.
The display section 8 includes a liquid crystal panel and displays a blood vessel image or a measurement result on the basis of an image signal output from the control section 10. The display is switched in accordance with the state of the device 1. For example, screens corresponding to a standby state, a blood vessel position adjustment moment, and the completion of measurement are displayed on the display section 8.
The control section 10 is composed of an analog substrate and a digital substrate. A CPU 100a to be described later controls an operation of each section. The configuration of the control section 10 will be described in detail later.
The battery 13 includes a lithium ion secondary battery and a secondary battery including a nickel-cadmium rechargeable battery or the like and supplies electric power to the display section 8, the control section 10 and the image pick-up section 6.
The lower housing 22 includes a front chassis section 22a, a back chassis section 22b, side end sections 22c for connecting the front chassis section 22a and the back chassis section 22b, a box-shaped battery receiving section 220 connected to the lower sides of the side end sections 22c and a first fixing member 25 attached to the lower side of the front chassis section 22a.
Both ends of the back chassis section 22b are bent inwardly and provided with a spring supporter 22d horizontally extending in the Y1 direction. The spring supporter 22d is formed in a cylindrical shape, and as described later, a spring 15 is mounted on the spring supporter 22d. The box-shaped battery receiving section 220 receives the battery 13. The back side of the battery receiving section 220 is provided with an opening 240 and a battery cover 24 is attached after the battery 13 is received in the battery receiving section 220.
The first fixing member 25 has a framework 25a and a back wall section 25b connected to the bottom section of the battery receiving section 220. A cover member 26 is attached to the front surface of the first fixing member 25. The cover member 26 includes a plate-shaped member of which the lower side is round.
The slide member 4 includes a slide member body 40 and a back surface cover member 47. The slide member body 40 includes a frame member 41 having left and right side wall members 41a and 41b and a connecting wall section 41c for connecting the left and right side wall members 41a and 41b, connecting sections 42, each of which extends downwardly from the left or right side wall member 41a or 41b via a step section 45, and a plate-shaped second fixing member 43 connected to the frame member 41 by the connecting sections 42. The second fixing member 43 is a plate-shaped member suspended with respect to the connecting sections 42 and has a rectangular window section 430 at the center thereof. A thin wall is formed on the back side of the second fixing member 43 via the step sections, and a thickness when the back surface cover member 47 is attached is the same as the width of the connecting section 42.
The inside of the left and right side wall members 41a and 41b of the frame member 41 is provided with a suspending piece section 44a, a horizontal piece section 44b extending in the Y2 direction from the upper end of the suspending piece section 44a, and a spring supporter 44c extending parallel to the side wall in the Y2 direction from a side surface of the suspending piece section 44a.
The back surface cover member 47 is a member having a shape and a size to be attachable to the thin wall formed on the back surface of the second fixing member 43. On the inside of the back surface cover member, bearing sections 47a for holding a spindle 111 provided in the separation preventing member 11 and a pair of spring receiving sections 47b for holding one ends of springs 113 are provided.
The separation preventing member 11 has a size to be fitted to the window section 430 provided in the second fixing member 43. The front wall section of the separation preventing member forms an inclined surface from the upper end to the lower end thereof. A side surface of the separation preventing member 11 is provided with the rod-shaped spindle 111 and an engaging member 112.
The receiving section 5 is a member for receiving the image pick-up section 6 and includes an inner housing 51, a turret 52, an elastic member 53, an outer housing 54 and the image pick-up section rotating section 55.
The inner housing 51 is provided with a cylindrical section 511 in which the image pick-up section 6 is received, an extending section 512 extending forwardly from the cylindrical section 511, a circular opening 514 provided in the extending section 512 and a cylindrical fitting section 513 provided at the opening edge of the opening 514. The turret 52 includes a cylindrical framework and is provided with, at the center thereof, a window section 520 to which an image pick-up surface of the image pick-up section 6 is fitted. The outer housing 54 includes a cylindrical section 541 provided to correspond to the cylindrical section 511 of the inner housing 51 and an extending section 542. The image pick-up section rotating section 55 includes a cylindrical substrate 551, a fitting section 552 having a smaller diameter than the substrate 551 and fitted to an opening 540 of the outer housing 54, and a plurality of spring supporters 553 provided inside the substrate 551 to support a plurality of compression springs 63 attached to the image pick-up section 6.
The image pick-up section 6 received in the receiving section 5 includes a light source section 61 for illuminating a living body and a CCD image pick-up element 62 for imaging a site of the living body illuminated by the light source section 61.
The CCD image pick-up element 62 is disposed in back of the holding plate 61a so as to pick up an image of the image pick-up area CR. A lens (not shown) is provided between the opening 61b provided at the center of the holding plate 61a and the CCD image pick-up element 62, and the CCD image pick-up element 62 picks up a living body image formed via the lens and sends an image signal to the control section 10.
The image pick-up section position adjusting section 7 includes the cover member 26 attached to the first fixing member 25 of the device body 2, an elastic member 17 and the fitting section 513 provided in the extending section 512 of the inner housing 51.
Next, the configuration of the control section 10 will be described.
The CPU 100a can execute a computer program loaded to the main memory 100b. By executing the computer program to be described later with the CPU 100a, the device functions as a noninvasive living body measuring device.
The main memory 100b includes a SRAM, a DRAM or the like. The main memory 100b is used to read computer programs stored in a flash memory card 100j. When the computer programs are executed, the main memory is used as a work area of the CPU 100a.
The flash memory card reader 100c is used to read data stored in the flash memory card 100j. The flash memory card 100j has a flash memory (not shown), and can hold data even when electric power is not supplied from the outside. In the flash memory card 100j, a computer program to be executed by the CPU 100a and data to be used for the execution operation are stored.
In addition, for example, an operating system based on TRON specifications is installed on the flash memory card 100j. The operating system is not limited thereto and may be, for example, an operating system providing a graphical user interface environment such as Windows (registered trade name) made and distributed by Microsoft corporation, America. In the following description, the computer program according to this embodiment operates on the operating system.
The light source section input/output interface 100d includes an analog interface including a D/A converter and an A/D converter. The light source section input/output interface 100d is electrically connected to each of the 4 light emitting diodes R1, R2, L1 and L2 provided in the light source section 61 by an electric signal line to control operations of the light emitting diodes. On the basis of a computer program to be described later, the light source section input/output interface 100d controls currents which are applied to the light emitting diodes R1, R2, L1 and L2.
The frame memory 100e includes a SRAM, a DRAM or the like. The frame memory 100e is used to store data when the image input interface 100f to be described later performs image processing.
The image input interface 100f includes a video digitize circuit (not shown) including an A/D converter. The image input interface 100f is electrically connected to the CCD image pick-up element 62 by an electric signal line and an image signal is input from the CCD image pick-up element 62. The image signal input from the CCD image pick-up element 62 is A/D converted by the image input interface 100f. The image data subjected to digital conversion in this manner is stored in the frame memory 100e.
The input interface 100g includes an analog interface including an A/D converter. “Start/completion” key 91a and “measurement/record” key 91b are electrically connected to the input interface 100g. Thanks to this configuration, the user can select operation items of the device by using the “measurement/record” key 91b, and can turn on/off the device and execute the operation selected by the “measurement/record” key 91b by using the “start/completion key 91a”.
The communication interface 100h includes, for example, a serial interface such as USB, IEEE1394 or RS232C, or a parallel interface such as SCSI. The control section 10 uses a predetermined communication protocol by the communication interface 100h to transmit/receive data to/from an external access device such as a mobile computer or a cellular phone. In this manner, the control section 10 sends measurement result data to the external access device via the communication interface 100h.
The image output interface 100i is electrically connected to the display section 8 and outputs a video signal based on the image data applied from the CPU 100a to the display section 8.
The assembly of the device body 2 will be described with reference to
Next, the lower housing 22 is inserted into a hollow section 49 surrounded by the connecting sections 42 of the slide member 4 so that one ends of the springs 15 are each mounted on the spring supporter 22d provided in the lower housing 22 and the other ends are each mounted on the spring supporter 44c provided inside the left or right side wall member 41a or 41b of the slide member 4, as shown by the dotted lines of
The springs 15 supported by the lower housing 22 and the slide member 4 apply a pressing force to the lower housing 22 and the slide member 4. The lower housing 22 is pressed against the slide member 4 in the Y2 direction and the slide member 4 is pressed against the lower housing 22 in the Y1 direction. At this time, when ends 22e of the front chassis section 22a of the lower housing 22 are each brought into contact with the suspending piece section 44a of the slide member 4, the movement of the lower housing 22 pressed in the Y2 direction is stopped at a certain position. Further, the horizontal piece sections 44b provided inside the left and right side wall members 41a and 41b prevent the springs 15 attached to the spring supporters 44c from being upwardly separated. In addition, when the side end sections 22c of the lower housing 22 are disposed at the step sections 45 provided inside the left and right side wall members 41a and 41b, the separation of the lower housing 22 is prevented and the slide movement of the lower housing 22 in the Y1 and Y2 directions is guided.
In a state in which the lower housing 22 and the slide member 4 are connected to each other by the springs 15, the upper housing 21 to which the liquid crystal cover 23, the operation key 91, the switch substrate 92, the display section 8, and the control section 10 are attached is mounted and the upper housing 21 and the lower housing 22 are fixed by screws inserted from the lower side of the lower housing 22. The battery 13 is received in the battery receiving section 220 of the lower housing 22 via the opening 240 and the opening 240 is closed by the battery cover 24.
Next, the separation preventing member 11 and the back surface cover member 47 are attached to the slide member 4. First, one ends of the springs 113 are each held by a spring holding section provided in the back surface of the separation preventing member 11 and the other ends are each held by the spring receiving section 47b of the back surface cover member 47. The spindles 111 provided in the side surfaces of the separation preventing member 11 engage with the bearing sections 47a of the back surface cover member 47, respectively. In addition, the separation preventing member 11 is fitted to the window section 430 of the second fixing member 43 and the back surface cover member 47 is attached to the second fixing member 43. The back surface cover member 47 is attached to the thin wall provided on the back side of the second fixing member 43 and the second fixing member 43 and the back surface cover member 47 are fixed by screws. At this time, the lower side of the separating preventing member 11 is pressed toward the second fixing member 43 by a pair of the springs 113. However, since the engaging member 112 provided in the side wall of the separation preventing member 11 engages with the outer edge of the window section 430, the separation preventing member 11 is held in a state in which the lower end thereof protrudes from the window section 430. In addition, the separation preventing member 11 can be freely taken out and put in by an elastic force of the springs 113.
Next, the combination of the receiving section 5 will be described. First, the turret 52 is inserted into a cylindrical opening 510 of the inner housings 51 to fit the holding plate 61a of the image pick-up section 6 to the window section 520 of the turret 52. Next, the outer housing 54 is fixed to the inner housing 51 by screws and the image pick-up section rotating section 55 is inserted into the cylindrical opening of the outer housing 54. At this time, the plurality of spring supporters 553 provided in the image pick-up section rotating section 55 are mounted on the plurality of compression springs 63 provided in the image pick-up section 6, and the fitting section 552 of the image pick-up section rotating section 55, around which the elastic member 53 is wound, is inserted into the outer housing 54. During the rotation of the image pick-up section rotating section 55, the elastic member 53 applies a suitable amount of a frictional force to a surface between the fitting section 552 and the outer housing 54 and functions as coming-off preventing means for the image pick-up section rotating section 55. By connecting the image pick-up section rotating section 55 to the image pick-up section 6 via the compression springs 63, the image pick-up section rotating section 55 and the image pick-up section 6 can integrally rotate. Further, by an elastic force of the compression springs 63, the image pick-up surface of the image pick-up section 6 presses a surface of a living body by a proper amount of pressure when the image pick-up surface of the image pick-up section 6 is brought into contact with the living body.
Next, the connection of the device body 2 and the receiving section 5 will be described using
The device 1 having such a configuration is mounted on the wrist of the user as follows. First, when the connecting wall section 41c of the slide member 4 and the device body 2 are grasped by hand from the state shown in
The user inserts the arm between the first fixing member 25 and the second fixing member 43 while grasping the connecting wall section 41c of the slide member 4 and the back chassis section 22b of the device body 2 and then releases the grasped connecting wall section 41c and device body 2. When a grasping force disappears, the springs 15 connecting the device body 2 and the slide member 4 try to return to their original state by their own elastic force and thus the device body 2 is pushed in the Y1 direction and the slide member 4 is pushed in the Y2 direction. In this manner, the interval between the first fixing member 25 and the second fixing member 43 is narrowed, the arm inserted between the first fixing member 25 and the second fixing member 43 is elastically pressed and caught therebetween, and thus the device 1 is fixed to the arm.
As is obvious from
Consequently, the device 1 according to this embodiment can be mounted on the arm only by the operation of grasping the connecting wall section 41c and the device body 2 with one hand and separating them from each other and the mounting on the arm is very easy.
Further, the distance between the first fixing member 25 and the second fixing member 43 is adjustable and thus it is possible to deal with even arm thicknesses different from one user to the next. Generally, the difference in arm thickness (thickness between palmar side and back side of hand of arm) among individuals is smaller than the difference in arm width (length in direction perpendicular to arm thickness direction). Like the device 1 according to this embodiment, thanks to the configuration in which the arm is fixed by being caught in the thickness direction, it is possible to widely deal with the arm thicknesses different from one user to the next. In addition, thanks to the configuration in which the palmar side and the back side of the hand of the arm are caught, the contact area between the first and second fixing members 25 and 43 and the arm can be largely ensured and the device 1 becomes difficult to separate from the arm.
Since the arm of the user is pressed by a predetermined pressure with the use of the first fixing member 25 and the second fixing member 43, the blood flow in the vicinity of the wrist which is an image pick-up site is blocked and the blood vessel of the wrist expands. Accordingly, the device 1 functions as a pressure belt and thus a good blood vessel image can be picked up and hemoglobin concentration can be measured without the use of a pressure belt.
Next, the measurement operation of the device 1 will be described.
Then, in Step S3, the CPU 100a is in a standby state until the “start/completion” key 91a is pressed. When a standby state screen is displayed on the display section 8 and then the user presses the “start/completion” key 91a (Yes in Step S3), the process proceeds to Step S4.
After that, first, the CPU 100a lights the light emitting diodes R1, R2, L1 and L2 provided in the light source section 61 with a predetermined light intensity. The image pick-up area CR (see
Next, the CPU 100a determines whether the luminance of the area B is in an objective range or not (Step S6). When the luminance of the area B is beyond the objective range, the light source section input/output interface 100d is used to adjust the current amounts flowing to the light emitting diodes R1, R2, L1 and L2 and adjusts the light intensities of them (Step S7). The process returns to Step S4. When the luminance of the area B is in the objective range (Yes in Step S6), the CPU 100a sets a y coordinate value of a calculation target of a luminance profile to be described later to an initial value (40) (Step S8). In addition, a luminance of the pixel from an end to the other end of the x coordinate of the set y coordinate value (40) is obtained.
Then, the CPU 100a determines whether the blood vessel pattern 401 is positioned in the area 401c (see
When it is determined that the blood vessel pattern 401 is not positioned in the area 401c in the determination process of Step S115, the CPU 100a performs a process of acquiring a position relationship of the blood vessel pattern 401 and the area 401c in Step S161. Herein, the position relationship is information on, for example, whether the blood vessel pattern 401 is positioned in the left side or the right side of the area 401c, the blood vessel pattern 401 is partially positioned in the area 401c or not, the entire blood vessel pattern 401 is accommodated in the area 401c or not if the image pick-up section 6 is rotated, or the like.
Then, on the basis of the position relationship of the blood vessel pattern 401 and the area 401c acquired in Step S161, the CPU 100a determines the direction in which the image pick-up section 6 should be moved (Step S162) and performs a process of displaying the arrows 402a to 402d for indicating on the display section 8 the direction in which the image pick-up section 6 should be moved (Step S163). Steps S162 and S163 will be described with reference to
For example, when the blood vessel pattern 401 is positioned on the right side of the area 401c as shown in
Similarly, when the blood vessel pattern 401 is positioned on the left side of the area 401c as shown in
As described above, when the display for the indication for horizontally moving the image pick-up section 6 is displayed, the user moves the image pick-up section 6 by the image pick-up section position adjusting section 7 in accordance with the direction of the arrows 402a to 402d so as to accommodate the blood vessel pattern 401 in the area 401c and adjusts the position.
Meanwhile, for example, as shown in
In this manner, when the display for the indication for rotating the image pick-up section 6 is displayed, the user rotates the image pick-up section 6 in the clockwise direction or a counterclockwise direction by the image pick-up section rotating section 55 in accordance with the direction of the arrows 402a to 402d so as to accommodate the blood vessel pattern 401 in the area 401c and adjusts the image pick-up direction of the image pick-up section 6.
When the direction in which the image pick-up section 6 should be moved is displayed in Step S163, the CPU 100a allows the process to return to the main routine.
When Step S16 is ended, the CPU 100a allows the process to return to Step S4. The CPU 100a captures a picked-up image of the image pick-up area CR again and performs the processes of Steps S4 to S15. The process ranging from the capturing of the picked-up image of the image pick-up area CR in Step S4 to the determination in Step S15 is performed for 1/100 seconds and the display of the display section 8 is also updated for 1/100 seconds. These processes are repeatedly performed even as the user adjusts the position of the image pick-up section 6, and thus the user adjusts the position of the image pick-up section 6 while confirming the display of the display section 8 which is updated as needed. The position adjustment operation is performed by the user and the processes of Steps S4 to S16 are repeated until it is determined that the blood vessel pattern 401 is positioned in the area 401c in the determination process of Step S15.
When, as a result of the position adjustment operation performed by the user, it is determined that the blood vessel pattern 401 is positioned in the area 401c in Step S15 (Yes in Step S15), the CPU 100a activates the “start/completion” key 91a to continue the measurement (Step S17). At this time, the CPU 100a allows all the arrows 402a to 402d to flash as shown in
In Step S19, when it is determined that the “measurement/record” key 91b is pressed (Yes in Step S19), the CPU 100a measures hemoglobin concentration (Step S20). After the measurement, a measurement result display screen is displayed on the display section 8, as shown in
Herein, in this embodiment, the value of the luminance is a digital converted value (varying from 0 to 255) of an 8-bit A/D converter of the used image input interface 100f. This is because, since the luminance of the image has a proportional relationship with a size of the image signal input from a CCD camera 52c, the A/D converted value of the image signal (0-255) is set as the value of the luminance.
When the average luminance of the area B exceeds 100 (Yes in Step S103), the CPU 100a obtains a luminance profile PF1 and a concentration profile NP1 independent from an incident light intensity about the image obtained in Step S102 (Step S105). Further, the CPU 100a controls the light source section input/output interface 100d to illuminate with a proper light intensity the living body including a blood vessel by the light emitting diodes L1 and L2 (second light source section) which are the other light source among the light sources disposed on both sides with the blood vessel interposed therebetween (Step S106) and images the illuminated site by the CCD image pick-up element 62 (Step S107). Further, the CPU 100a determines whether the average luminance of the area B exceeds 100 or not (Step S108), and when the luminance does not exceed 100, the CPU uses the light source section input/output interface 100d to increase the current amounts flowing to the light emitting diodes L1 and L2 to thereby adjust the light intensity of them (Step S109) and the process returns to Step S107.
When the average luminance of the area B exceeds 100 (Yes in Step S108), the CPU 100a subjects the image obtained in Step S107 to the same process as Step S105 and obtains a luminance profile PF2 and a concentration profile NP2 independent from an incident light intensity (Step S110).
The CPU 100a calculates a peak height h1 and a center of gravity coordinate cg1 from the concentration profile NP1 obtained by Step S105 and calculates a peak height h2 and a center of gravity coordinate cg2 from the concentration profile NP2 obtained by Step S110, respectively. Using the calculated values, the CPU calculates a blood vessel depth index S by the following equation (1). The CPU 100a stores the calculation result in the frame memory 100e (Step S111).
S=(cg2−cg1)/{(h1+h2)/2} (1)
The CPU 100a also calculates the light intensity and the intensity ratio of the light sources (light emitting diodes R1 and R2 and light emitting diodes L1 and L2) on the right and left of the blood vessel on the basis of the luminance profile PF1 obtained by Step S105 and the luminance profile PF2 obtained by Step S110 (Step S112). Then, the CPU adjusts the light intensity of both the light sources on the basis of the obtained result (Step S113).
Subsequently, the CPU 100a controls the light source section input/output interface 100d to illuminate the image pick-up area CR (see
When the average luminance of the area B exceeds 150 (Yes in Step S115), the CPU 100a creates a luminance profile (distribution of luminance B at position X) PF showing a first luminance distribution (
D=h/w
n (2)
Where n is a constant indicating the nonlinear expanse of the half-value width caused by scattering. When there is no light scattering, n=1; and when there is light scattering, n>1.
Next, on the basis of a blood vessel surrounding tissue image in the living body image obtained in Step S101, the CPU 100a calculates a tissue blood amount index M indicating the amount of blood contained in the adjacent tissue. Specifically, a second luminance distribution distributed along the blood vessel image is extracted on the basis of the blood vessel surrounding tissue image in the living body image disposed at a predetermined distance (for example, 2.5 mm) from the blood vessel image in the living body image. Not only the target blood vessel but also the tissue surrounding the blood vessel is imaged in the living body image. Since the light attenuates in proportion to the amount of blood in the tissue, the amount of blood in the surrounding tissue can be estimated by calculating the light attenuation rate of the surrounding tissue. The CPU 100a stores the measurement result in the frame memory 100e (Step S119).
The CPU 100a calculates a correction coefficient fs on the basis of the blood vessel depth index S calculated in Step S111 and a correction coefficient fin on the basis of the tissue blood amount index M calculated in Step S120. Then, using the coefficients, a corrected hemoglobin concentration Do is calculated by the following equation (3) (Step S121).
Do=D×fs×fm (3)
The CPU 100a stores the calculation result in Step S121 in the frame memory 100e (Step S122) and the process returns to the main routine.
In this embodiment, the description has been made for the noninvasive living body measuring device for measuring the hemoglobin, but is not limited thereto. Various changes can be made if the device measures biological information on the basis of the image obtained by imaging a site of the wrist. For example, the device may measure a blood speed by continuously picking up living body images.
In addition, in this embodiment, the configuration has been employed in which the receiving section 5 is rotated by the image pick-up section position adjusting section 7, but is not limited thereto, and various configurations can be employed. For example, the receiving section 5 may be pivotally connected to the first fixing member 25. Otherwise, the receiving section 5 may include a female-type member and a male-type member which can be slidably inserted into the female-type member and may be configured so as to be stretchable.
Further, in this embodiment, the configuration has been employed in which the receiving section 5 is connected to the first fixing member 25 via the image pick-up section position adjusting section 7, but is not limited thereto. The receiving section 5 may be connected to the device body 2 via the image pick-up section position adjusting section 7.
Further, in this embodiment, the configuration has been employed in which only the second fixing member 43 is provided with the separation preventing member 1, but is not limited thereto. The first fixing member 25 may be provided with the separation preventing member 11 or both of the first and second fixing members 25 and 43 may be provided with the separation preventing member 11.
Further, in this embodiment, the configuration has been employed in which on the positioning screen of the image pick-up section 6 (see
Moreover, in this embodiment, the configuration has been employed in which the CPU 100a automatically repeats the processes of Steps S4 to S16 every predetermined period of time ( 1/100 second interval) until it is determined that the blood vessel pattern 401 is positioned in the area 401c in the determination process of Step S15 of
The user moves or rotates the image pick-up section 6 in accordance with the display of the arrows 402a to 402d displayed on the display section 8 in Step S16 to adjust the position of the image pick-up section 6 so as to position the blood vessel pattern 401 in the area 401c. When determining that the position adjustment operation is completed, the user presses the “start/completion” key 91a. When the user presses the “start/completion” key 91a (Yes in Step S22), the CPU 100a allows the process to return to Step S4 and performs the processes of Steps S4 to S15 again. In Step S15, it is determined whether the blood vessel pattern 401 is positioned in the area 401c or not, and when it is not determined that the blood vessel pattern 401 is positioned in the area 401c, the CPU 100a allows the process to proceed to Step S16 again and performs a process of instructing the direction in which the image pick-up section 6 is moved. The detailed process of Step S116 is performed in the same manner as that described with reference to
According to this configuration, after adjusting the position of the image pick-up section 6, the user can know whether the blood vessel pattern 401 is positioned in the area 401c or not at an arbitrary timing. In addition, the device 1 is not necessary to continuously capture and analyze the picked-up image and thus it is preferred in view of saving power consumption.
Number | Date | Country | Kind |
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2007-336392 | Dec 2007 | JP | national |