US008670819B2
`
`a2) United States Patent
`US 8,670,819 B2
`(0) Patent No.:
`Iwamiyaetal.
`Mar. 11, 2014
`(45) Date of Patent:
`
`(54) OPTICAL BIOLOGICAL INFORMATION
`DETECTING APPARATUS AND OPTICAL
`BIOLOGICAL INFORMATION DETECTING
`METHOD
`
`(75)
`
`Inventors: Hiroshi Iwamiya, Ome (JP); Shuji
`Nakajima, Kunitachi (JP)
`
`(73) Assignee: Casio Computer Co., Ltd, Tokyo (JP)
`
`(*) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 567 days.
`
`(21)
`
`Appl. No.: 12/825,601
`
`(22)
`
`Filed:
`
`Jun. 29, 2010
`
`(65)
`
`Prior Publication Data
`
`US 2011/0004106 Al
`
`Jan. 6, 2011
`
`(30)
`
`Foreign Application Priority Data
`
`Jul. 1, 2009
`Aug. 18, 2009
`Dec. 22, 2009
`Feb. 17, 2010
`
`(IP) eecsssssssseeseeseesseesesseeee 2009-156985
`(IP) eesssssssssesseeseesssesseseeee 2009-188987
`
`(JP) eecssssssssssseeseesseeseeseeee 2009-291174
`(IP) eesssssssssesseeseesssesseseeee 2010-032088
`
`(51)
`
`(52)
`
`(58)
`
`(2006.01)
`
`Int. Cl.
`A61B 6/00
`US. Cl.
`USPC woes cseseeteneneees 600/476; 606/9; 604/20
`Field of Classification Search
`CPC woe ceeeeeseneeeens A61B 1/227; A61B 5/1076
`USPC woes cseseeteneneees 600/476; 606/9; 604/20
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`7,733,224 B2*
`2005/0177140 AL*
`2009/0198173 Al*
`2010/0191125 Al*
`
`6/2010 Tran ween 340/540
`
`8/2005 Jaywc 606/9
`8/2009 Samuel etal.
`..
`w 604/20
`7/2010 Fogedetal. wu... 600/476
`
`FOREIGN PATENT DOCUMENTS
`
`JP
`JP
`JP
`JP
`
`4/2000
`2000-116611
`12/2001
`2001-353133
`12/2004
`2004-337605
`10/2008
`2008-237686
`OTHER PUBLICATIONS
`
`Japanese Office Action for Application No. 2010-032088 mailed on
`Nov.16, 2011.
`
`* cited by examiner
`
`Primary Examiner — Baisakhi Roy
`(74) Attorney, Agent, or Firm — Turocy & Watson, LLP
`
`ABSTRACT
`(57)
`An optical biological
`information detecting apparatus
`includesa light emitting unit which emits observation light of
`a specific wavelength band to optically observe a desired
`portion of a tissue of a skin of a humanbody, and an annular
`light guide unit which guidesthe observation light to a desired
`area of a surface of the skin corresponding to the desired
`portion of the tissue of the skin, and which annularlyirradi-
`ates the observation light onto the desired area of the surface
`of the skin. The apparatus further includes a light receiving
`unit whichis disposed at a position surroundedby the annular
`light guide unit, and which receives scattered light scattered
`by the desired portion of the tissue of the skin after the
`observation light is annularly irradiated onto the desired area
`of the surface of the skin by the annular light guide unit.
`
`9 Claims, 25 Drawing Sheets
`
`51
`
`55
`7ia 56
`61 4, 33b67te79 71C
`
`
`
`53a
`55b 55a
`71b
`71
`70b
`57
`33 43
`70
`} 53b \*"e0et
`71ao, 7
`71b
`55a
`55b
`
`
`
`
`
`
`
`6ic
`713
`33a 77/972 629361
`
`eve 67]/let6
`ape
`
`53 x 54
`
`
`
`
`
`
`53aP °
`
`67
`
`60
`
`APPLE 1004
`
`APPLE 1004
`
`1
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 1 of 25
`
`US 8,670,819 B2
`
`
`
`2
`
`

`

`
`
`
`
`3
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 3 of 25
`
`US 8,670,819 B2
`
`V——Z
`
`PutEdbEPu
`ASTORZEIGEOgTO
`RXR
`
`€5)ebbA?“pateons7SyyMeh
`grO¢L}GL\ZL/CCk/LL|CLL9OL
`PelSLa,\ct
`ILzpbol6SLLLOLE
`
`PEL
`
`
`
`4
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 4 of 25
`
`US 8,670,819 B2
`
`yaaaSSp>S4NSSaN
`
`
`
`5
`
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 5 of 25
`
`US 8,670,819 B2
`
`H
`
`LYMPHATI
`
`BLOOD
`VESSEL” CAPILLARY
`
`LAMINA
`
`PAPILLARY
`AYE
`
`SUBPAPILLARY
`AYE
`
`H2 EPIDERMIS
`ABOUT 0.1 mm
`O 0.2 mm)
`
`RETICULAR
`LAYER
`
`Hit DERMIS
`(ABOUT 2 mm)
`
`
`
`SUBCUTANEOUS
`TISSUE
`
`FIG.5
`
`6
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 6 of 25
`
`US 8,670,819 B2
`
`' NEAR INFRARED
`ULTRAVIOLET ‘
`LIGHT
`|_‘VISIBLELIGHT _ ‘
`LIGHT
`pi
`a
`
`|
`o>
`
`-
`z=
`Wi
`Oo
`br
`o
`3
`2
`ce
`Oo
`i
`x
`r
`
`2
`
`10
`
`10
`
`1
`
`9ul
`
`
`
` \ ee beseseeeeees RELATIVELIGHTEMISSIONSTRENGTH
`
`LIGHT ABSORBING COEFFICIENT OF MAIN LIGHT ABSORBING
`SUBSTANCE IN LIVING BODY AND SCATTERING COEFFICIENT OF SKIN
`e [mMme")
`o. [me]
`108
`
`us
`[mm"]
`
`be
`i
`oOis
`i
`oO
`2
`ocuu
`E
`4
`8
`
`400
`
`600 700
`
`1000
`
`3000
`
`FIG.
`
`
`RELATIVE LIGHT EMISSION STRENGTH OF LIGHT EMITTING UNIT
`
`each Oo
`
`F3
`
`0.5
`
`!
`
`--f
`
`°
`750
`
`800
`
`850
`
`900
`
`950
`
`1000
`
`1050
`
`WAVELENGTH4 (nm)
`
`
`FIG.7
`
`7
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 7 of 25
`
`US 8,670,819 B2
`
`SPECTRAL CHARACTERISTIC BY TRANSMITTANCE
`
`F OPTICAL FILTER
`
`(%)
`TRANSMITTANCE
`
`900
`™ “50Oo 600 staan 700.“300 é
`WAVELENGTH2 (nm)
`
`7 000
`
`
`
`SPECTRAL SENSITIVITY CHARACTERISTIC OF
`LIGHT RECEIVING UNIT
`
`100%}----------festeessesfeeeeeeeeeedfeoreneerecdeeeeeneece depgemmggfeces foveseenees
`
`80% fbccnbonnecee
`
`SENSITIVITY '
`RELATIVE
`
`yArr Joona nen cti nc en cc ece bec ee enn nebo Nees cceb eee ee cee
`‘
`‘
`fo’
`:
`:
`on
`|
`:
`! Z|
`!
`|
`PA
`40% fon ennnocb nnnonc en eden rence fececceret fesse cecfec een
`:
`:
`:
`'
`1
`'
`'
`f |:
`'
`:
`'
`:
`Yt
`1
`os
`1
`1
`'
`'
`1
`¥
`1
`g
`’
`1
`4
`'
`+
`'
`XY:
`ff
`1
`1
`t
`1
`t
`\
`y
`'
`t
`‘
`‘
`‘
`ly bomen hn nn ne rie ne ie ne de ene de eee chan n enn es eee
`£
`'
`'
`'
`‘
`1
`:
`gr’
`:
`,
`1
`,
`:
`‘
`1
`'
`'
`1
`'
`;
`700
`
`°
`
`o%E a
`400
`
`,
`
`500
`
`600
`
`800
`
`900
`
`1000
`
`1100
`
`1200
`
`WAVELENGTH(nm)
`
`
`
`8
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 8 of 25
`
`US 8,670,819 B2
`
`24
`
`23
`
`POWER SUPPLY
`UNIT
`
`DISPLAY UNIT
`
`
`
`25
`
`SWITCH
`UNIT
`
`
`
`|
`|
`
`|
`
`22
`TV CONVERTING|
`
`[LIGHTEMITTING ||) frape
`
`UNIT DRIVING) }-> LIGHTEMITTING |
`|
`_cincur
`|! LN J
`|
`as | OBSERVATION
`{LIGHT
`
`
`
`6
`
`7-4
`
`H—~|
`"|
`g—(|
`
`|
`
`17
`
`LGHT GUIDE UNIT
`
`_LIVING BODY
`INCLUDING SKIN
`SCATTERED LIGHT
`TAKING UNIT
`OPTICAL FILTER
`
`PORTION OF OBSERVATION
`
`LIGHTABSORBEDAND
`:
`1 SCATTEREDIN SKIN AND
`LIVING BODY
`1-9
`TLIGHT RECEIVING!
`
`|
`
`|
`
`9
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 9 of 25
`
`US 8,670,819 B2
`
`
`
`
`
`BaeeeapeeeeeeaeeeeeaeefeeT
`
`PEELEETIEeg
`
`ceF)Ze
`
`10
`
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 10 of 25
`
`US 8,670,819 B2
`
`
`
`11
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 11 of 25
`
`US 8,670,819 B2
`
`TENGNEY?ATTNEileNASVb
`9€epcrLEwieAbeyee5p/Seioneetabeeaee,gLopeVEgpPlELeo1
`
`
`Edible“SS
`at
`ZaSorrToTzdPT
`Ze8Lyly(9€bya,a|GhLEoe=LbOopece56
`
`etNir)
`
`ewaesXhoBos
`
`WEgic
`
`N=—
`
`12
`
`
`€
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 12 of 25
`
`US 8,670,819 B2
`
`7
`
`inESS
`RRRSNieeWY
`ZINUELN
`
`NGSSSSLESS
`
`\X
`
`Leelere
`
`ee
`
`9€)|PEEe
`€VaceSE
`
`ve
`
`
`
`aveegezelPlEiegy
`
`IVE
`
`FEZNULLAAWreLEOrnrrrrncSEUISON“K,
`
`GH
`
`SNOANVLNOENS
`
`SNSSLL
`
`i
`
`Ne
`
`/,eMYWSTIRS
`CTT ~“_=.~—_~aJfak
`
`no
`
`13
`
`13
`
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 13 of 25
`
`US 8,670,819 B2
`
`
`
`
`
`Beheeee
` ZIENON
`
`14
`
`14
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 14 of 25
`
`US 8,670,819 B2
`
`SNOANVLNOENS
`
` JNSSIL
`WERVIVESAWFelarder
`
`
`
`Lehnerealboekenook}oebonndinnh—hoahonekaharnhadSoapbeeoma
`
`
`
`
`
`eenaharnomemareahotorntoentl
`
`SP
`
`15
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`1
`
`it
`
`
`
`7,
`
`D>
`
`16
`
`16
`
`
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 16 of 25
`
`US 8,670,819 B2
`
`
`
`
`
`17
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 17 of 25
`
`US 8,670,819 B2
`
`SapaWhNK\KitexUpKe7feaWASWN<<WSVaA.WAACneAWKINSWINNRESRYSANRdsNX09~rie“wssau.|euAS“ageRes“8
`
`
`
`
`AAG:ANG
`aecleLATSWZ
`
`qeg°F9///29ag9
`
`eeg9929919)&4/8ZLene
`97922,,22®LOee69
`
`Lg
`
`GGggPLZ
`
`
`
`18
`
`18
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 18 of 25
`
`US 8,670,819 B2
`
`
`
`6ipn”'60 53a
`
`
`5sbeae 6lae
`
`51
`
`SA
`LDF Para 606 CAs
`537 ACARI 8262
`53
`
`3
`
`60b
`
`60b
`
`67 3c 63 66
`
`66 63 3c 67
`
`64
`
`FIG.21
`
`19
`
`19
`
`

`

`U.S. Patent
`
`US 8,670,819 B2
`
`Mar. 11, 2014
`
`Sheet 19 of 25
`
`
`
`52
`|
`52
`57
`55
`Zia 7Ob
`70b 7;
`55
`
`58a|\70|56 56 a
`
`55b
`55b
`
`) NOUNTie Fie NV
`_ Zp700_70c QZ _
`PS
`INt~71 ZL
`IN
`(55a
`IZMwhy ZZ
`
`
`QO =|(SL, 75 ZA
`
`{
`74'72 77(72\76
`
`3b3C 75
`73
`73
`3C 3b
`
`
`
`FIG.23
`
`20
`
`20
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 20 of 25
`
`US 8,670,819 B2
`
`
`
`ANSSIL\UtemayTO,\.\NaTAe+t.{>SNOANWLNIENS--~----Leon\Sh..,.‘.‘.x‘.‘‘pout.!a"\N\iy7i“7\\\\/TeeILeawTy..\NN~N..‘‘‘7oe|!_>Lepf.~Lge.5S~LH--
`IeoXSYsSTNSZSI=ito~~.
`
`FESeg/09/s¢/19/oz/2s]ev!se/ev|zsJoz/19!ass\o9\e598Sys
`“77i‘.‘.‘_N‘‘,an‘‘aN\ooweeeeeeeZeefoenme
`
`wL-leer9~7LtCEaee
`RRQVWISARRLARLYSSQWMVGARSRAN
`-—7Xx~~
`TAILLE
`eesaggeggLGLZ9SBESGEEIZ9GLSBGsggeEs
`_—ANSSNS.)SYé¥\.\~~.
`f7SeoRTTRLfoueeaco~€9“~xSOTee
`“7\Po
`Leard‘xXN\S‘NA*TTS
`_—Aan~oecoroAES—Maose\.vs
`
`INSSTeeLy;WAU
`WRKNAGWNN
` €
`A\W\\
`
`GH
`
`———H
`
`i
`
`21
`
`21
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 21 of 25
`
`US 8,670,819 B2
`
`LLL)RSs
`
`SY
`“
`SX
`
`Lh
`LZk
`
`NSTTSSTSSenasnoaNwunoansByeSpronBSPmLenNyee\|XN‘fo\‘‘t>aLH---~1--eeeSuNSW73~—ShapSfee'wTNINZAaALyFSSNINSagaRSaayaSPaesNisWieKOZINiNVRCESSLEZAZZZNNNIINY
`ansslAedse8S
`
`SGESec/09/s¢
`<NGa6RRA
`begaggecgIGIL9GBEEAEE
`UaeoTi\>\.\N\x.\~>~
`
`e9aiaabsoSSySTickededbetON,“9ys
`eT.COSTSAAC
`19/02;cS|vy|SE/Sp
`ANZAAW
`e251aeza
`SSAAN Ze
`129GLGBGGgg
`
`cS/0Z/19|4SS\09
`
`ER
`wyN
`bo2g
`BS
`SS]
`C2
`LD.
`Liz
`
`
`Se
`
`A Sa
`
`eSdeppbat
`
`beg
`
`/
`
`md
`
`22
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 22 of 25
`
`US 8,670,819 B2
`
`
`
`SNOANVLNONS-
`
`ANssiL
`
`fk
`
`96°
`
`xXSx1PNeeedeeeeTT
`
`PTTTTSeSe~~
`
`GH-
`|it4
`
`LH--
`
`|cz
`
`IAeAN
`
`
` Veeeee;YLLofalatoRr|VILLE207<<WSg¢/09/s¢/19/02/25/ey|ee]eb/ze/oz/19|as¢\o9\egIESzs
`
`ESTE.
`
`-J\eArreTwoosfonaUe-c7
` eeetteteefeeene!}~ee_-tf~oaTt;_ao!!--“7Iiooeeeeebeetpetfed
`
`oO}
`Begaqggegg1GIZ9GBESEEIZ9SISBGGggees
`eZeZZb9eaeg.€90S:i
`
`23
`
`
`
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 23 of 25
`
`US 8,670,819 B2
`
`
`
`
`
`|
`
`
`
`FIRST LIGHT EMITTING
`
`PORTION DRIVING CIRCUIT
`
`IN CONVERTING
`
`\55
`
`OPTICAL FILTER
`SECOND
`FIRST
`SECOND
`FIRST
`SCATTERED
`LIGHT GUIDE|LIGHT GUIDE
`LIGHT GUIDE|LIGHT GUIDE
`LIGHT TAKING
`MEMBER
`MEMBER
`MEMBER
`MEMBER
`UNIT
`
` ~~ 84
`
`
`
`
`
`FIG.27
`
`24
`
`24
`
`

`

`U.S. Patent
`
`Mar.11, 2014
`
`Sheet 24 of 25
`
`US 8,670,819 B2
`
`
`
`
`
`
`
`
`
`
`LIGHT EMISSION CONDITIONS OF INNER CIRCUMFERENTIAL SIDE
`LIGHT IRRADIATION PATH AND OUTER CIRCUMFERENTIAL SIDE
`LIGHT IRRADIATION PATH
`
`
`LIGHT RECEIVING LIGHT RECEPTION|LIGHT RECEPTION
`
`NIT
`CONDITION 1
`CONDITION2
`
`INNER CIRCUMFERENTIAL SIDE
`LIGHT IRRADIATION PATH
`
`
`
`O : LIGHT EMISSION
`< : LIGHT NON-EMISSION
`
`OUTER CIRCUMFERENTIALSIDE
`LIGHT IRRADIATION PATH
`
`
`
`
`
`PULSE SIGNAL
`COMPONENT
`
`LIGHTRECEPTIONAMOUNT
`
`
`LIGHTRECEPTIONAMOUNT
`
`-
`
`PULSE SIGNAL
`COMPONENT
`
`-——— -~ BODY MOTION
`NOISE
`
`
`
`
`
`
`
`FIG.29B
`
`= QB
`
`i
`us
`WO
`cs
`—_4
`aa
`
`PULSE SIGNAL
`COMPONENT
`
`oSsevell
`
`TIME
`
`FIG.29C
`
`25
`
`25
`
`

`

`U.S. Patent
`
`Mar. 11, 2014
`
`Sheet 25 of 25
`
`US 8,670,819 B2
`
`FIRST BIOLOGICAL INFORMATION
`DETECTING PROCESS
`
`S31
`
`CAUSE LIGHT EMITTING UNIT TO EMIT LIGHT
`
`$32
`ANNULARLY IRRADIATE OBSERVATION LIGHT ONTO SKIN
`BY LIGHT GUIDE MEMBE
`
`SEE}
`
`RECEIVE SCATTERED LIGHT BY LIGHT RECEIVING UNIT
`
`DETECT BIOLOGICAL INFORMATION BASED ON
`wn
`ATTERED LIG
`x=]
`
`$34
`
`END
`
`
`
`941
`
`9342
`
`a|
`
`SECOND BIOLOGICAL INFORMATION
`DETECTING PROCES
`
`DETECT FIRST BIOLOGICAL INFORMATION
`
`DETECT SECOND BIOLOGICAL INFORMATION
`
`S843
`CALCULATE BIOLOGICAL INFORMATION UNIQUE TO MEASURER
`
`END
`
`
`
`26
`
`26
`
`

`

`US 8,670,819 B2
`
`1
`OPTICAL BIOLOGICAL INFORMATION
`DETECTING APPARATUS AND OPTICAL
`BIOLOGICAL INFORMATION DETECTING
`METHOD
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is based upon and claims the benefit of
`priority from prior Japanese Patent Applications No. 2009-
`156985, filed Jul. 1, 2009; No. 2009-188987,filed Aug. 18,
`2009; No. 2009-291174, filed Dec. 22, 2009; and No. 2010-
`032088, filed Feb. 17, 2010,the entire contents of all ofwhich
`are incorporated herein by reference.
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The presentinventionrelates to an optical biological infor-
`mation detecting apparatus and an optical biological infor-
`mation detecting method that can optically detect biological
`information.
`2. Description of the Related Art
`Asdescribed in Japanese Patent Application KOKAI Pub-
`lication No. 2001-353133, an optical biological information
`detecting apparatus combined with a wristwatch has been
`known.
`An optical biological information detecting apparatus of a
`wristwatch type comprises a light emitting unit that emits
`observation light having a predetermined wavelength and a
`light receiving unit that receives scattered light of the obser-
`vation light emitted from the light emitting unit and scattered
`in a biological tissue, which are provided on a back cover of
`the wristwatch. The optical biological information detecting
`apparatus causes thelight emitting unit to intermittently emit
`light for a constant time with a constant period, causes the
`light receiving unit to receive the scattered light from the
`biological tissue according to pulsative light emission of the
`light emitting unit, performs photoelectric conversion, per-
`forms a frequency analysis on signals obtained by continuous
`observation for a predetermined time, and estimates biologi-
`cal information, such as a pulse wave.
`The outline of an operational principle of the biological
`information detecting apparatus is as described above. How-
`ever, according to the operational principle, absorbance
`where hemoglobin of blood absorbs light greatly changes at
`about 600 nanometers (hereinafter, simply referred to as nm),
`and the absorbanceis very high at a wavelength shorter than
`600 nm, as compared with a wavelength of 600 nm or more.
`For this reason,light having the wavelength shorter than 600
`nm is generally used as the observation light emitted from the
`light emitting unit.
`However, the biological information detecting apparatus
`according to the related art uses dermis including a blood
`capillary in a surface of a skin and epidermis containing
`melanine pigmentofthe surface side as an observation object
`of a pulse wave. However, if a large amount of melanine
`pigmentis contained in the epidermis, the observation light
`may be absorbed by the melanine pigment. As a result, bio-
`logical information, such as a pulse wave, cannot be accu-
`rately detected.
`That is, the melanine pigment has extraordinarily high
`absorbance in a wavelength band from ultraviolet light to
`visible light. When the large amount of melanine pigmentis
`contained in the epidermis (for example, in the case of a
`person of a dark skin color), even though observation light
`having a wavelength of 600 nm orlessis irradiated onto the
`
`15
`
`25
`
`40
`
`45
`
`50
`
`55
`
`2
`skin, the observation light that reaches the dermis including
`the blood capillary, repeats scattering and absorption in a
`dermis tissue, passes through the epidermis again, and arrives
`at the light receiving unit is weak light and cannotbe suffi-
`ciently received. Therefore, biological information, such as a
`pulse wave, cannotbe detected.
`The biological information detecting apparatus according
`to the related art is configured such that the light emitting unit
`and the light receiving unit are two-dimensionally disposed
`on an observation light taking plate, light emitted from the
`light emitting unit is irradiated onto the skin through the
`observation light taking plate facing the surface of the skin,
`scattered light thereof is taken by the observationlight taking
`plate, and the scatteredlight is received by the light receiving
`unit through the observation light taking plate. When the light
`emitted from the light emitting unit is incident in the skin
`from the observation light taking plate, a portion of the light
`maybe reflected on an inner surface of the observation light
`taking plate, and thelight reflected on the inner surface ofthe
`observation light taking plate may be received by the light
`receiving unit as light noise. As a result, only the scattered
`light from the skin cannot be accurately detected.
`
`BRIEF SUMMARY OF THE INVENTION
`
`it is an object of the present invention to
`Accordingly,
`provide anoptical biological information detecting apparatus
`and an optical biological information detecting method that
`can efficiently and stably receive scattered light returned from
`a skin among observation light irradiated onto the skin and
`accurately and easily detect biological information.
`In order to achieve the above described object, an optical
`biological information detecting apparatus according to one
`aspect of the present invention, comprises: a light emitting
`unit which emits observation light of a specific wavelength
`bandto optically observe a desired portion ofa tissue ofa skin
`of a human body; an annular light guide unit which guides the
`observation light to a desired area of a surface of the skin
`correspondingto the desired portion of the tissue of the skin,
`and which annularly irradiates the observation light onto the
`desired area of the surface of the skin; and a light receiving
`unit whichis disposed at a position surroundedby the annular
`light guide unit, and which receives scattered light scattered
`by the desired portion of the tissue of the skin after the
`observation light is annularly irradiated onto the desired area
`of the surface of the skin by the annular light guide unit.
`An optical biological
`information detecting method
`according to one aspect of the present invention in order to
`achieve the above described object,
`is used in an optical
`biological information detecting apparatus, the optical bio-
`logical information detecting apparatus comprising: a light
`emitting unit which emits observation light of a specific
`wavelength bandto optically observe a desired portion of a
`tissue of a skin of a human body; an annular light guide unit
`which guides the observation light to a desired area of a
`surface of the skin correspondingto the desired portion ofthe
`tissue of the skin, and which annularly irradiates the obser-
`vation light onto the desired area of the surface of the skin;
`and a light receiving unit which is disposed at a position
`surrounded by the annular light guide unit, and which
`receives scattered light scattered by the desired portion of the
`tissue of the skin after the observation light is annularly
`irradiated onto the desired area of the surface of the skin by
`the annular light guide unit.
`And,the optical biological information detecting method
`according to the one aspect of the present invention com-
`prises: causing the light emitting unit to emit observation
`
`27
`
`27
`
`

`

`US 8,670,819 B2
`
`3
`light; annularly irradiating the observation light emitted from
`the light emitting unit onto the desired area of the surface of
`the skin by the light guide unit; receiving the scattered light
`after the irradiated observation light
`is scattered by the
`desired portion of the skin tissue, by the light receiving unit
`through the scattered light taking unit; and detecting biologi-
`cal informationofthe desired portion ofthe skin tissue, based
`on the scattered light received by the light receiving unit.
`An optical biological
`information detecting method
`according to another aspect of the present invention in order
`to achieve the above described object, is used in an optical
`biological information detecting apparatus, the optical bio-
`logical information detecting apparatus comprising: first and
`second light emitting portions each ofwhich emit observation
`light of a specific wavelength band to optically observe a
`desired portion of a tissue of a skin of a human body;first and
`second light guiding ring portions which are mutually con-
`centrically disposed, which guidethe observationlights emit-
`ted from thefirst and secondlight emitting portionsto desired
`area of a surface of the skin corresponding to the desired
`portion ofthe tissue ofthe skin, and which annularlyirradiate
`the observation lights onto the desired area of the surface of
`the skin; a scattered light taking unit which is disposed at a
`position surroundedbythefirst and secondlight guiding ring
`portions, which contacts the desired area of the surface of the
`skin, and which takes scattered lights after the observation
`lights annularly irradiated onto the desired area of the surface
`of the skin bythe first and secondlight guiding ring portions
`are scattered by the desired portion ofthe tissue of the skin;
`and a light receiving unit which is positioned at a side of the
`scattered light taking unit which is opposite to the surface of
`the skin and which receives the scattered lights through the
`scattered light taking unit.
`And, the optical biological information detecting method
`comprises: causing the first and second light emitting por-
`tions to simultaneously emit the observation lights, guiding
`the observation lights emitted from the first and second light
`emitting portions to the desired area of the surface of the skin
`corresponding to the desired portion ofthe tissue of the skin
`by thefirst and secondlight guiding ring portions, annularly
`irradiating the observation lights onto the desired area of the
`surface of the skin, receiving the scattered lights after the
`irradiated observation lights are scattered by the desired por-
`tion ofthe tissue ofthe skin by the light receiving unit through
`the scattered light taking unit, and detecting first biological
`information ofthe desired portion ofthe skin tissue, based on
`the scattered lights received by the light receiving unit; caus-
`ing only thefirst light emitting portion to emit the observation
`light, guiding the observation light emitted from thefirst light
`emitting portion to the desired area ofthe surface of the skin
`corresponding to the desired portion ofthe tissue of the skin
`bythefirst light guiding ring portion, annularly irradiating the
`observation light onto the desired area of the surface of the
`skin, receiving the scattered light after the irradiated obser-
`vation light is scattered by the desired portionofthetissue of
`the skin by the light receiving unit through the scattered light
`taking unit, and detecting second biological information of
`the desired portion of the skin tissue, based on the scattered
`light received by the light receiving unit; and processing the
`first biological information and the second biological infor-
`mation and calculating biological information unique to the
`human body where the observation lights are irradiated.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWSOF THE DRAWING
`
`The accompanying drawings, which are incorporated in
`and constitute a part of the specification, illustrate embodi-
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`ments of the invention, and together with the general descrip-
`tion given above and the detailed description of the embodi-
`ments given below, serve to explain the principles of the
`invention.
`FIG.1 is a schematic longitudinal cross-sectional view ofa
`body case of a wristwatch where an optical biological infor-
`mation detecting apparatus according to a first embodiment
`of the present invention is combined;
`FIG. 21s a plan view ofa main portion ofa back cover ofthe
`wristwatch of FIG.1;
`FIG.3 is a cross-sectional view taken along a line II-IIJ in
`FIG.2;
`FIG. 4 is an enlarged cross-sectional view illustrating a
`state where biological information, such as a pulse wave, is
`detected while the back cover of the wristwatch illustrated in
`FIG. 1 contacts the skin of an arm;
`FIG. 5 is a schematic enlarged cross-sectional view of a
`tissue of the skin illustrated in FIG. 4;
`FIG.6 is a diagram illustrating a relationship between a
`scattering characteristic and a light absorbing characteristic
`of a main light absorbing substance of a biological tissue in
`the skin illustrated in FIG.5;
`FIG. 7 is a diagram illustrating a relative light emission
`strength characteristic in observation light ofan infrared band
`emitted by a light emitting unit illustrated in FIG. 4;
`FIG.8 is a diagram illustrating a spectral characteristic by
`transmittance of an opticalfilter illustrated in FIG. 4;
`FIG. 9 is a diagram illustrating a spectral sensitivity char-
`acteristic of a light receiving unit illustrated in FIG.4;
`FIG. 10 is a block diagram illustrating a configuration of a
`circuit of the optical biological information detecting appa-
`ratus according to the first embodimentof the present inven-
`tion;
`FIG. 11 is a schematic longitudinal cross-sectional view of
`a bodycase of a wristwatch where anoptical biological infor-
`mation detecting apparatus according to a second embodi-
`mentof the present invention is combined;
`FIG. 12 is an enlarged view of a main portion of a back
`cover of the wristwatch of FIG. 11;
`FIG.13 is a cross-sectional view taken along a line XIII-
`XIIin FIG. 12;
`FIG. 14 is a cross-sectional view illustrating a state where
`biological information, such as a pulse wave,
`is optically
`measured while the back cover ofthe wristwatch illustrated in
`FIG.13 contacts a skin of an arm;
`FIG. 15 is a schematic cross-sectional view of a body case
`of a wristwatch where an optical biological
`information
`detecting apparatus according to a third embodimentof the
`present invention is combined;
`FIG.16 is a cross-sectional view illustrating a state where
`biological information, such as a pulse wave,
`is optically
`measured while the back cover ofthe wristwatch illustrated in
`FIG. 15 contacts a skin of an arm;
`FIG. 17 is a schematic cross-sectional view of a body case
`of a wristwatch where an optical biological
`information
`detecting apparatus according to a fourth embodimentof the
`present invention is combined;
`FIG.18 is a plan view of a main portion of a back cover of
`the wristwatch of FIG. 17;
`FIG. 19 is a cross-sectional view taken along a line XIX-
`XIX in FIG. 18;
`FIG.20 is a schematic enlarged plan view of only an outer
`circumferential side light irradiating path of FIG. 18;
`FIG.21 is a cross-sectional view taken along a line XXI-
`XX] in FIG. 20;
`FIG. 22 is a schematic enlarged plan view of only an inner
`circumferential side light irradiating path of FIG. 18;
`
`28
`
`28
`
`

`

`US 8,670,819 B2
`
`5
`FIG.23 is a cross-sectional view taken along a line XXIII-
`XXIII in FIG. 22;
`FIG.24is a cross-sectional view illustrating an irradiation
`state (irradiation area E1) of observation light when bothfirst
`and second light emitting portions are made to simulta-
`neously emit light while the back cover of the wristwatch
`illustrated in FIG. 19 contacts a skin of an arm;
`FIG.25is a cross-sectional view illustrating an irradiation
`state (irradiation area E2) of observation light when only the
`first light emitting portion is made to emit light after the
`irradiation state (irradiation area E1) of the observation light
`illustrated in FIG. 24;
`FIG.26 is a cross-sectional view illustrating an estimated
`irradiation state (irradiation area E3) of observation light
`when biological information, such as a pulse wave, is opti-
`cally measuredafterthe irradiationstate (irradiation area E2)
`of the observation light illustrated in FIG. 25;
`FIG.27is a block diagram illustrating a configuration of a
`circuit of the optical biological information detecting appa-
`ratus according to the fourth embodiment of the present
`invention;
`FIG.28 is a table illustrating light emission conditions of
`an outer circumferential side light irradiation path and an
`inner circumferenceside light irradiation path in the optical
`biological information detecting apparatus of FIG. 27;
`FIG. 29A is a diagram illustrating a state where biological
`information, such as a pulse wave, is detected by the optical
`biological information detecting apparatus of FIG. 27, and
`illustrating a pulse wave signal when boththefirst and second
`light emitting portions are madeto simultaneously emitlight
`as shown in FIG.24;
`FIG.29Bis a diagram illustrating a state where biological
`information, such as a pulse wave, is detected by the optical
`biological information detecting apparatus of FIG. 27, and
`illustrating a pulse wave signal whenonlythefirst light emit-
`ting portion is made to emit light as shown in FIG.25;
`FIG. 29C is a diagram illustrating a state where biological
`information, such as a pulse wave, is measured bythe optical
`biological information detecting apparatus of FIG. 27, and
`illustrating an estimated pulse wave signal whenthe biologi-
`cal information, such as the pulse wave, is optically detected
`as shown in FIG.26;
`FIG. 30 is a flow chart illustrating an optical biological
`information detecting method according to a first embodi-
`mentof the present invention; and
`FIG. 31 is a flow chart illustrating an optical biological
`information detecting method according to a second embodi-
`mentof the present invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`First Embodiment
`
`Hereinafter, a first embodiment where the invention is
`applied to a wristwatch will be described with reference to
`FIGS. 1 to 10 and 30.
`
`55
`
`Asillustrated in FIG. 1, the wristwatch comprises a wrist-
`watch case 1. In an upper opening of the wristwatch case 1, a
`watch glass 2 is mounted through a packing 2a. Below the
`wristwatch case 1, a back cover 3 is mounted through a
`waterproof ring 3a. In the wristwatch case 1, a time piece
`module 4 that has various components needed for a watch
`function is disposed.
`In a central portion of the back cover 3 of the wristwatch
`case 1, a biological information detecting apparatus 5 is pro-
`vided, as illustrated in FIGS. 1 to 3. In this case, the back
`cover 3 is formed of a metal, such as stainless steel. As
`
`60
`
`65
`
`29
`
`6
`illustrated in FIGS. 3 and 4, a bottom surface ofthe back cover
`3 protrudes to the lower side while being moderately curved
`toward the central portion, and a mounting hole 35 used to
`mount the biological information detecting apparatus 5 is
`provided in the protruded central portion to penetrate the
`central portion up and down.
`Asillustrated in FIGS. 3 and 4, the biological information
`detecting apparatus 5 comprises light emitting units 6 that
`emit observation light of a specific wavelength bandto opti-
`cally observe a skin tissue of a human body, an annular light
`guide unit 7 that guides the observation light emitted from the
`light emitting units 6 and annularly diffuses andirradiates the
`observation light with respect to a skin H, a scattered light
`taking unit 8 that contacts the skin H positioned in a central
`portion of an annular irradiation area E wherethe observation
`light is irradiated by the annularlight guide unit 7, and a light
`receiving unit 9 that is disposed in a place positioned at the
`side opposite to the skin H inthe scattered light taking unit 8
`and receives scattered light of the observation light taken by
`the scattered light taking unit8.
`In this case, the light emitting unit 6 andthe light receiving
`unit 9 are provided on a bottom surface of a circuit board 10
`for measurement, as illustrated in FIGS. 1 to 4. The circuit
`board 10 is positioned on the light guide unit 7 and is disposed
`in the wristwatch case 1. The light guide unit 7 is mounted in
`the back case 3 in a state where its lower sideis fitted into the
`
`10
`
`15
`
`20
`
`25
`
`mounting hole 34 of the back cover 3 and its upper side is
`disposed on an inner surface (top surface in FIG. 1) of the
`back cover 3.
`
`30
`
`35
`
`40
`
`45
`
`50
`
`Meanwhile, the light emitting unit 6 is composed ofa light
`emitting diode (LED)and is configured to emit infrared light
`(Ap=940 nm) where absorbance of melanine pigment con-
`tained in the skin H is low asthe observation light. Asillus-
`trated in FIGS. 3 and 4, the light emitting units 6 are provided
`in two placesof the 3 o’clock side and the 9 o’clock side ina
`bottom surface of the circuit board 10 corresponding to the
`light guide unit 7, respectively.
`The light guide unit 7 comprises a light guiding ring por-
`tion 11 and a diffusion/irradiation ring portion 12, as illus-
`trated in FIGS. 3 and 4. The light guiding ring portion 11 is
`formed in almost a ring shape, using a material such astrans-
`parent glass or a transparent resin with a high light transmit-
`ting property. The light guiding ring portion 11 has the con-
`figuration wherea flat ring portion 11a andan inclined ring
`portion 114 that is inclined to the oblique lower side toward
`the central side of the ring portion 11a from an inner circum-
`ferential surface thereof are integrally formed. In the places of
`the 3 o’clock side and the 9 o’clock side of the top surface in
`the flat ring portion 11a, concave portions 11¢ wherethe light
`emitting units 6 are disposed are provided.
`Thereby, as illustrated in FIG. 4, the light guiding ring
`portion 11 is configured such that an inner surface of each
`concave portion 11c in theflat ring portion 11a 1s formed in an
`incident surface 11d, the observation light emitted from the
`incident surface 11d by thelight emitting unit 6 is taken in the
`flat ring portion 11a, and the taken observation light is emitted
`from an emission surface 11e formed in a lowerfront end of
`
`the inclined ring portion 114 while being annularly guided by
`the flat ring portion 11a.
`In this case, as illustrated in FIGS. 3 and 4, on an external
`surface of the light guiding ring portion 11, a first reflection
`layer 13 is provided by a metal vapor deposition method,
`exceptfor the incident surface 11d ofthe flat ring portion 11a
`and the emission surface 11e of the inclinedring portion 115.
`Thefirst reflection layer 13 prevents the observation light,
`
`29
`
`

`

`US 8,670,819 B2
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`8
`7
`light taking unit comes into contact with the protrusion por-
`whichis incident in the innerportion ofthe light guiding ring
`tion 12¢ provided in an inner circumferential surface in the
`portion 11, from leaking to the outside of the light guiding
`diffusion/irradiation ring portion 12 of the light guide unit 7
`ring portion 11