CA2062270A1 - Photoplethysmographics using phase-division multiplexing - Google Patents
Photoplethysmographics using phase-division multiplexingInfo
- Publication number
- CA2062270A1 CA2062270A1 CA002062270A CA2062270A CA2062270A1 CA 2062270 A1 CA2062270 A1 CA 2062270A1 CA 002062270 A CA002062270 A CA 002062270A CA 2062270 A CA2062270 A CA 2062270A CA 2062270 A1 CA2062270 A1 CA 2062270A1
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- signal
- signals
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- detector
- modulating
- Prior art date
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/41—Detecting, measuring or recording for evaluating the immune or lymphatic systems
- A61B5/414—Evaluating particular organs or parts of the immune or lymphatic systems
- A61B5/417—Evaluating particular organs or parts of the immune or lymphatic systems the bone marrow
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/314—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths
- G01N21/3151—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths using two sources of radiation of different wavelengths
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
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- Spectroscopy & Molecular Physics (AREA)
- General Health & Medical Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- Veterinary Medicine (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
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- Immunology (AREA)
- Vascular Medicine (AREA)
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- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
Abstract
Photoplethysmographics Using Phase-Division Multiplexing Abstract First and second carrier signals, distinguishable by phase, are respectively applied to infrared and red energy emitters. A detector receives the sum of the energy after modulation at the infrared and red wavelengths. The sig-nal received by the detector is then demultiplexed into its original first and second components, thereby allowing determining of both the infrared and red modulation compo-nents. The first and second carrier signals may comprise time-varying periodic signals with identical frequency and frequency spectra, such as a pair of sine waves which are indistinguishable except by phase and amplitude. A 90°
phase difference is preferred, but any phase other than 0 or an integer multiple of 180° is workable. A carrier frequency which avoids excessive interference from ambient light is preferred.
phase difference is preferred, but any phase other than 0 or an integer multiple of 180° is workable. A carrier frequency which avoids excessive interference from ambient light is preferred.
Description
MAR, ~ "~2 19:0~ 2~227~) P. ~/36 Q~Q~I
e~
This invelltlon r~ o pho~opl~3~hy~mc~L~aphio~.
More ~p~lfi;::~lly, thi~ invontlon r~la~ o ph~sQ-division mul~ipl~xing and d~mu:l~lploxlng o~ ~ign~ or 5 in~r~r~d and red ~b~or~ion o~ ~looa .
e~
This invelltlon r~ o pho~opl~3~hy~mc~L~aphio~.
More ~p~lfi;::~lly, thi~ invontlon r~la~ o ph~sQ-division mul~ipl~xing and d~mu:l~lploxlng o~ ~ign~ or 5 in~r~r~d and red ~b~or~ion o~ ~looa .
2. ~
It iE~ w~ll known in thl3 art ~o ~oll~ot pho~o-plethysmographic data 6~imultanllao~ y ~t e~ ural-ity of en~rgy ~avel~n~h~. For ~axampls, blood oxygon conc~n-o tration may ba m~asur~d by do~e~mining ab~orption by apa~ien~ ~ ~ ti~u~ on in~rarsd and r~d ll~h~: ~ t21e degr~
o~ absorpti4n i~ ~ypl~ally ~ ront ~or th~0e two wav~-lengtho. In~rar~ And rsd llç~t ~r~ ~mitt~ lnto thæ
patiant ' ~ ti~aue~ (~ . g ~, by infri~r~ and r~ EDs) and ~ho 15 total energy rec~ived to b~ d~t~ d by a ~in~le d~tector (e . g., a p~otod~odo~ . How~v~r, on~ pro~l~m i~ th~t t~
signal produaad by th~ ~e~ctor mu~c b~ prs~ ed to separa~ ~he infrar2d and re~ por~ions ~rom each othe~.
on~ m~thod o~ th~ prior ~r~ ;h~wn ir~ ~. S . P~tent 20 No. 4, 407, 290. Tima-divi~ion multiplexing i~ u~d to al~ornat~ly 3witch on the ini~ar~d and r~d ~mitt3r~, ak a fr~quency great~r than the pati~nt~ pulo~ ~te. Tha dete¢tor ~ign~ then s~parat~d into lll~r~red and ræd portion~ by ~ampling in ~ynchr~ny with th~ on/o~f ~w~ t~h-2g ing of th~ in~rar~ and r~d emittera.
Whil~ t~is3 m~khod ~ucce~sPu~ ly ~parat~ th~ in~rar~dand red portion~, it q~n~r~lly r~aquire~ that slamplinçl th~
d~te~tor ~i~nal mu~t b~ ~ynchros~ 3d wlth the on~o~
~awitching of ~e in~rar~d and r~d ~mittero. It i~ al60 30 di~fi~ult ~hile u~ing this m~thod ~o ~omp&nsa ~ for nois3 :
:
MAR 3 ~ î 09 ~ 3~7 i3 p ~/36 ~ources ~uah a~ an~içnt liç~h~ and ~l~ctrom~n~tia int~r~r~nco ~
A ~3cond m~thod o ~ prior ar~ hown in u. 5 .
Pakant No. 4, ~oo, 885. Thc~ in~rar~d ~nd red amitt~r~ ar~
5 ~riv~n at two di~f~3rent ~r~quonc~ s . Th~ d~t~ctor . ign~l i5 then sep~a~ed into tn~rar~d an~ r~ portiono by tet~ing a~ thos~ two dl~or~nt ~equ~n~
While ~hi~ me~h~d E;uc~e~u.lly ~pa~at~ th~ in~rare~
and red portions, the m~thod d~sc:rlb0d in ~h~ patent lo requir~ demultiploxin~ nals whiah are phaæ~-synchronized with the Inultipl~x:Lng freqll~noi i3~, An~ pro-duces a high~r pow~r output t-ha~ th~ ~im~-divi~ion mulki-plexing ~nethod. Al~o, whll~3 th:i& ml3thod m~ avold noi~
sou~ce~ at pr~d~t~rmin~d and X:nown ~r~quRalci~a, it i~
15 di~ioult to ~omp~n at~ ~or noi~ sourc~ whic~h wor~ not kno~n be~ore ~h~ multiplexing ~r~uencis~ w~r4 ~o~an, particularly b~scaus~ two sepa~ate ~r~qu~ncie~ which ar~a fre~ of i~t~3r~r6~n4e mus~ ~ ho~n.
Su~ ~y Q~, ~o The invQnkion provi~f~s a m~hod o~ pho~opl~khysmo~
graphiç:~ by phas~ division multiplexing (as d~s~in~d herein) arld d~mul~iplexing o~ ~ign~l s Sor in~rar~d and red a~sorpl:ion o~ bloo~. Flrst and s~aond ~arri6~r ~iqnalç, dis~.ing~ a)~le by ~ha~a, ~r~ re~p~a~iv~ly appli~d to 25 ~ n~rared and r~3d on~rgy ~mittor~ o~ rec~lv~ th3 sum of the ~nar~y a~t~r mo~ul~tio.n at th~ in~rar~d a~d re~d w~valengkh~. Th~ ~ignal rec~iv0d by tl~ d~l:æctor 1~ th~r damultipl~xe~d lnt~ i'C5 original ~lr~t ~nd ~cond comp3~
n~nts, th~r~by allowin9 ~t~rmin:in~ o bo~h ~h~ in~rarod 30 and rad modulatlon component~.
In A p~err~d ~mbodim~n'c, ~h~ ~irst and ~econd car-rler signals may ~ompri$6t tim~ axyins~ p~ariodio signal~
wi~h identical ~xequenoy and ~r~uency ~i;p~tra, ~Lueh a~ a palr of ~ine wav~s ~Ynich ar~ in~l~.stingui~habl~ xcspt by 35 pha~e ~nd ampli~ud~. ~ 90~ ph~e ~ rence i~ prsferr~d, but any phase oth~r th~n o or an :int~g~ar multlpl~ of 180U
i .
MAR; ~ 2 0 ~ 7 ,1~ P 7/30 i~ workabl~. Al~o, a aarri~r ~r~qu~ncy which ~void~
exce~ive int0rforenae ~rom ambi~nt light i~ pxæ~red, such a~ 3 0 H2 .
5Figure 1 show~ a blocX di~ am oP a p~lo~opl~thysmo-graphic system c:ompri3ing an o~n~odim~nt or th~ inv~ntion.
Figure 2 ehow~; a blook ~liagr~lm Or 'ch~ pha~-divi~ion znultipl6~xer and d~mul~ipl~x~r ~ an #~mbodiment. Or the ~nvention .
10 ~
~ n em~odim~nt o~ ~hl~ in-r~n~ion m~y be u~ed to~e~r with inv~ntions whioh ar~ ~is~103~d in ~ ~:op~nding appli-c~tion titlsd "P~OTOPLETHYSMO~ PHICS tJgING EIIE~GY-REDUCINC; WAVEF~RM S~APINGI~, application S~rial No.
15 Lyon & ~yorl ~oa~et No. 191~23~, Pil~d th~ ~uq~ ~Ay in th~
nam~ o~ tho 8t~ nY~nltors, her~ y in~ rpora . ~d by r~r-ence a~ if ~ully a~t ~orth h~r~in.
Figure 1 ohows a bloo~ diagram o~ ~ p~o~opl~thysmo-graphic sys em aomprising an sm~odimen~ o~ t~e inv~ntion.
~oA plurality of ena~0y ~mitte~ 101 m~y ~ach bs t~n~d to a separate w~ ngth. In ~ p~`err~d ~bodim~nt ~or maasuring hlood oxyq~n, on~ o~ th~ ~mit~or~ 101 may co~0 pris~ an inX~r~d light emi~r and m~y op~r~t~ at a wav~-length o~ about 880 nan~m~ter~ nother on~ o~ the ~mit-~5 ters 101 may compriæ~ a r~d li~ht emit~er ~nd m~y o~rat~
at rl wa~elengt~ o~ abou~ 6~6 n~nom~t~r~ s u~ad he~in, "light" refers to el~atromagn~tic ~nergy of any w~v~-length, wh~thqr vi~ or not.) ~owev~r, it may ocour that o~h~ w~v~l~nyths m~y ~o u~ ul, ~uch ~ ~or maa~ur ing blood ~arbon dioxid~, blood car~on monoxld~, oth~r blood ya~ conc~ntrations, ~lood ~luco~, or moro gan~
ally, ot~er ch~miaal and/~r phy~ l Qono~tration~.
In a pr~ferred ~m~odim~nt, ~,ach o~ th~ emit~rh 101 may oo~pxl~ an LE~ ~uch aa p~rt n~mb~r 0~-8803 mada by Marktech Int~rnational ¢orp. ~or ~h~ infrar~d LED and part ,:
~ ~ ~ 2 2 I ~ P 8/3~
MAR; ~ '~ 19: lu number M~1500-PUR ~nadq by Mark~q~c~l Int~srn~lonal ~orp. Por the rqd LED), a~ ~ ~ w~ll 3cnown 1n ~ho art, ~nd may bo coupl~d by m~an~ o~ an ~ED drl~lror 102, ~3 ia well known in the art, ~o a carrisr ou~put 103 oi~ a muxf~mux alroui~
S 104 (~Qa ~igur~ 2~.
~ n~r~y :erom ~ omit~r~ 10 'I ls ~ppl 1 ~d ~o ~ t i91;~U~a saction 105 Or a pationt . In ~ pr~ærr~d. 02Rb4d.im~nt 20r mea~urin~ bloc~d oxyg~n, th~ t~e~lu~ a~ion lOS i~ pre~
~ bly cho~erl ~uc~h ~ha~ ~nfargy from tho ~mlt~,lDrs~ 101 pa~3~
lO through the patieht~ blood v~s~ , sauch a~ an ~nd o~ ths patient~ ~inger, ~he patier~ arlob~, or ~or n~onat~a) the pa~ nt ' g hahd ot ~oot ~ Th~ U~ tion lOS may modul~te the ~n~3rgy r~rom the ahli~t~3r~; lol, ~g i~
known in the art , ~ . g ., by abso~king ~om~ o~ th~ qnQrgy at 15 ~ach wavolength~ Typi~ally, ~n~3r~y ntay be modulate~i by tran~mi~ion throug~ ~h~ tisou~ ~ec~ion 105, but it may occur that enar~y may ~ ~nodula od by r~ otion o~ by othar Inaans~ . ...
A d~tootox 106 rec~iv~3 ~nergy a~t~r modulAt~ on by 20 the ti~su~ ~3cti on 105 and genl~rat~ n output ~l~n~l whicll in~icat~as th~a ~otal ~n~y r~c~iv~d. In & pr~rr~d embodiment, th~ ~etector 10~ ma!f comprisa a phot~diode ch aB par~ num~er OSI-1140 madl~ by opto S~nsor~, In~. ) as i~ w~311 lcnown ln ` ~-h~ a~ . A-~ ou~put o th~ d~tector 25 106 iB ampli~i~d by an ~mplifi~r :L07 and c:ouplq~ y m6lan~
of a filter 108 to a ~te~or input lns of the mux~d~mux c:lrcuit 104.
l'h~ muxjd~mux circult 104 gen~ra~eæ a ~ata ou~put eign~l 110 at a data. output 111, for oac~h anergy wa~
30 longt}l, whlch indiaat~s th~ modulation whlr!h th~ ti~uo se~tion 105 ~pplied to ~h~t ~n~:rgy w~ ngth. In a pr~Pferr~3d ernbodlm~n~ ~or me~uring blood oxyg~n, in~eo~
mation ~uch a~ blood oxyg~n oon~n~ration may b~ ~al~u~
lated from tllo output aign~l, as i~ woll known in th~ ~rt.
MAR;3 ' ~'~ 13~ P. 9/3 Pha~ li~s~
P~ase-divi~;ion multipl~xi~g~ as u~d h~r~
d~fin~d a3 follow~. In ~ a~ .lviE~ion ~ultipl~xing, ~
pl-~ral ity Or ~arrier ~i~fnals ~1ria :son~truct~d, ~ch or which may compris~ a mixt~r~ oi~ ~arrl~ ompon~nt0, and which ~re di~tin~uis~2~ablo by pha~ In a~ re~ i3rred ~m}:odlment, ~h~ carri~r sl~nal~ ~re i~en~ l ex~e,~t ~or p~se.~ h carrier ~gnal may ~:~ s~par~t~ly modula~d, an~ the r~sultants ~um~d. ~'h~r~d~t~r, th~ ~p~rat~
modulations may be ret::over~d fr~Dm th~ Sum, a~ di~lo~d herein .
In A pr~rr~d ~mbodiment, ~ f ir~ carrl~r ~ may comprise a slne wav~, e.g., ~o~ (2~ , and a o~cond ca~ri~r ,~ may oompri~ ~ sin~ wa~ w~ioh i~ pha~e-ahi~
~ith r~pect t~ th~ ~ir~t carrier, ~ in ~ 2~r ~l t) .
Alt~rnativ~ly, th~ ~irst oarri~r ~ may ~om~ri~ um o~
two ox mora ~arri6~r c:omponant6, ~.~., co~ (2~ fl t) ~ eos ( 27r f 2 ~), an~ tne second ~arri~ ~1 may as~mpri~e ~ 63urn, of two or mo~e c~arrier oompona~nt~ which is dl~tinguish~
from 'che ~iræk o~rri~3r by ph~ -, co~ ~2~ ~l t ~
+ co~ t2~T ~2 t ~ ~). Po~ibly, iE~ may c:ompris~ a h~r-monlc of ~l, but thi~ is not r~quir~.
The following ~elakion~ de~cribç~ s~epa:r~te modulation of each c~rri~r ~ignal, with a 90~ p~a~ dl~3r~nc~:
~ ~ co~ ~w t) (1~2) in (w t~ 1ll3) o - ml ~ + m2 ,~ (114) where w i ~ a c~rri~r freslu~ncy~ ml i~ ~ f`irst modu-lating ~f~c~ ~a. ~., at An in~ r~d wav*langth); m2 i~ a second m4dulating ~ff~c~ ~.5t" at a r~d w~va l~ns7th) ~ ~nd ~ doteate~d ~um o~ hs~ mo~lllat~sd çarri~r ~ign,s.l~
The d~toct~d ~u~n ~ is separat~ly multipli~cl by twic~
the f irst carrl~r ~ an~ ~y t~ia~ the ~econd c~rier ~:
~ ct o ~ ml ~ ml ~o~ ~ w ~) ~ m2 ~in t2 w ~) (115) 2 ~ n2 - m2 ao~ (~ w t) ~ ml ~in (2 ~ 116) P, 10/3 MA~, .3 `'`~ 19 1 1 Thos~ p~oduc~ a an~ a ~o ~iltere~d ~o ro~ov~r ml ancl ~
T~e following r~latlons dQ~rib~ ~opara'ce modLlla~ion o~ eaa~ c~rri~r signal, with ~ p~la~ dii~f~ nce oth~r th~n 5 90~:
C~ 3 C08 (W 't) 1117) ,~ ~ oos (w ~ i- ml ~ ~ m2 ,~
whera ~ h~ carrier ~requ~3ncy ~ mî i~ th~ t mod~ ting ~ t (~ t an in~rar~d wqvllalongth~ 7 m2 is ~e s~c:ond ~nodulatillg ~:efq-c~t ~ t ~ ~ed w~velength): and o i~ tha d~t~t~ um o~ ~he modu-lated c~rri~ar ~i~nal~ ~, a The det~cted ~um o i~ Popara~t~ly multlpli~d .by twlce 15 the rirst aarri~3r ~ and by twic6~ ths socond ca~rier ~:
2 ~x ~ = ml ~ ml cc1O ( 2 w t~ ~ m2 coaa (~) ~
m2 CoB (~ w t ~ ~p) (120) o = m2 ~ 3n2 ~o~; ( 2 w t ~ ml co~
ml ~ w t + ~ (121) ~o Theo~ pro~ucts 2 a and 2 ~ ,B 8~ llt~t~d t raoovar ml* and m2*.
ml* ~ ml ~ m2 oo~) (122) m2* ~ rnl 005(~) + m2 (123) or [ ] [ ] ~ ~ ] (124) co~ 1 n12 m2 or li; M ~ 1 * (7 25) whe~r~ X i a phaS~e-dep~n~n~ rnatrix ~ ~howns ~ i~ a vector o~ ~odulation e~f6~c~s ml, m~; and N~ i~ a v~o-tor oP mo~ulated oarri~r ~ompon~3nt partA ml~ 2~
Separate ~ompon~nt~ ml, m2 may b~ demultipl~X~d by multip~ ying by ~h~ left multlplic;a~ive inversæ of tho 35 pha~e-dep~nq~n~ ~n~tri~ ISt M ~ b ( 1 2 6 3 ~r ~5 = X 1 X ~5 ( 127 MAR, 3 ~ 12 20$~ P, 11/36 ~i Figure 2 ~3hs:w~ a ~loq~ dl~r~m s~ ~h~ phaEI~-dlvioion mul~ipl~x~r an~l do~hul~lpl~xBr 0~ e~r~ e3m~0di2n~n'c o~ th~
in~ention .
Th~3 di~3clo~ure hi3rein ~howsl ~ CA~i3e3 who~ b~th th~
f irst oarri~r and th~ ~cond ~;~rri~r ~ach comprl~ pur~
~ine waV1~9 W2~iC~ dl~r ill p~as6~ by ~x~tly ~0~. ~owq~ver, applying this ~i ~lo~ure t~ ca.3~ r~ ~lth~r ~h~ ~ir~
or tha se~ond carrler i~ n~t a Elure sin~ wav~, or ~h~re a 10 componen~ o~ ~ho ~irst and ~ ond carrier~ ef~r in pha~:o ~y oth~r than Qxac~ly 90~ would b~a c~ear to one o~
ordinary 5Xill in ~e art, af~3r peru~3al Or thQ sp~ci~ica-tion, drawings and cl i;n~ ~e~in.
A o~arrier generatc)r 201 qenera~l3 a plurality o~ car-15 rier ~ignals 202. ~n a pref~rrad ~mbodim~nt, taa~h carri~rsign~l 202 i~ alloc~t~ ko one ~mitk~r wavel~rtgth. Thu~, ther~ st carrier si~nal .202 alloaat~d to ini~r~r~d and a ~cond ca~ri~r si~n~l 202 alloa~d to r~d. ~l~o, ln a pr~rre~ odimsn~, each oarri~r sign~l 20~ may 20 oo~prise ~ sine w~v~ with ~re~oncy fl, a~ di~c103~d herein, and th~ two car~ier ~it~nal~ ~0~ y di~r in pha ~e by exactly ~ o ~ .
In a p~err~ad embodim~nt, ~ cho~an such that intarfar~nGa ~ro~n noise ~ourc~ uoh a~ ~mbi~nt light and eleo~romagne~l~ int~r~ll3r~n~e, i~ minimi~OEd. In ~ pr~-ferred embo~imant, Pl i~ al~o ~ho~en ~uch ~hat ~ b~ndwidth o~ ahout 4 H~ ~or the modulatin~ 3~fec~ o~ th~ tis~
section 105 i~ ~llow~d. Fr~uenol~ in t~e r~ng~ o~ a~o~t ~0-40 H&, suGh a~ 31.5 Hz, are pr~f~rr~d, but it would alaar to on~ o~ ordlnary skill irl the art, A~t~r p~ru~l of th~ ~p~ ic~ti~n, drawing~ ~In~ clalm~ h~rain, th~t other fr~qu~ncle~i wo~ld be work~bl~, and are within th~
~cop~ and ~pirit o~ the inv~rltion.
I~ w~uld aleo be cl~ar ko on~ o~ ordinarY ~kill in ~5 the ar~, a~ter paru~al ~E the ~ai~i~a~ion, drawing~ and clai~ns ller~in, that there i~ no rq~quirom~3nt ~hat the aom pon~nt~ o ~.h~ c:~rri~r sign~l ~02 mu~t b~ ~ine wav~o.
:
, ~ :
. ~ ~
.
MA~, ~'h' 19:13 2~2Yi~ P,12/36 Other ~yp~ of aarri~r oom~on~nt~ ;uoh a~ ~qu~re wav~ or oth~r wav~orms, would ~ wor:k~bl~, ~nd ~r~ withln the ~aope and . pirit of th~ inv~ntion~
It would 1:~13 oloax to on0 4~ o~llnary ~klll in th~
5 art, af~r E~eru~al o~ th~ s~c~ ~iaation, d~wing~ ~nd claim~ her~in, thAt there is no r~auir~ment th~t ths ~ir~3t aarriQr and th~ ~cond c~ r~i~r ~n~u~ di~r in ph~3l3 ~Dy ~xactly 9o'. CJth~r phaE~s~ di~33r~ oth~r thar3 0 or an inte~r mul~iple of l~O~ would be worka~l~, and ar~ w~ in lO ~he 8aOp~ and ~pirit P4 th~ invQntion.
It would al~o ba ol~aar to on~ o~ ordinary ~Xill in the art, a~ter peru~al o~ the e~ai~ic:A~ion~ drawing~ ~nd claims h~r~in, t}la~ th~ ~nv~an~ n m~y b~ ~d~p~d to measurement of oth~r oon3tltuo:nt~, s;u~h a~ blood ~:Arbon 15 dloxid~, bls~od o~rbon monoxid~, oth~r bloc~d g~ ao2~c~n-trationE~, blood gluqosQ, or mor~, ~9nlarally, oth~r ah~mic:~l and/or phy~ical 40ncan~r~tion~.
Eaah carri~r signal 202 :L~ ooupl~ad ~y ml3an$ 4f bri~htnc ~ amplifi~sr 203, ~or adju~ttn~ tho ~rightn~ o~
20 a corr~6pondin~ ~mitt~r lOl, ~ th~ ~orr~pond~ng o~rri~r output 103 oP ~he mux~d~mux cir3uit 104.
~ h~ d~tacto~ input lO~ ooupl~d, by m~an~ o~
first ~ilter 20~, for r~moving sompon~ntæ at ~r~ enc:is~
oth~r thar. the c~rri~r ~r~aquenGy, t~ ~a plurAlity o~ d~mul-25 tiplexor 21~:m~nt8 205 for d2m~l~ipls~xin~ ~ha modulatadfirst c~rrier s:ignal 20a ~rom th~ m~dulat~d ~saond carri~r signal ~ 02 . A oeo~nd input o~ C~ oi~ ~h~ d~multi~l~x~r ~l~ments 205 ill ooupl~d to on~ o~ th~ ~arrl~r oiçln~l~ 20~.
Th~3 carrier ai~nals 202 ar~ mul~ipliq~, and th~ pxo~uctæ
30 ar~ coup~sd, by m~an~ o~ ~ ~e3cond ~llt~r ~û~, fo~ r~movin~
compone,ntæ o~h~r ~han ba~band"~hlo~ ~how~ ths modulating ef ~ec~ o~ th~ ti~u~ tion 105, ~o producl3 thla data ou~pu~ nal ~ l l O .
The data oll~pUt ~ nal~ llO ~ach indi;:at~ ~h~3 mo~ula-35 tion ~ ct ~or the cor~pondlng carri~r ~ignal 202, a~multiplied by ~ oorr~ ion by l~h~ corr~Gponding b~igh~nes3 amplifier ~03. ~aah da~a outpu~ ~ignal llO i~ ~oupl~d ~o 4R; 3'g~ 19 13 2t~2~J P I~/30 th~ corr~sponding da~A ou~u~ l~.l o~ ~h~ mux/d~mux clrcult 104 .
In a pr~f~rr~d ~m:bo~imont, ~ n~l g~nar~tion and ~iy-n~l manipula~lon as d~cribad h~re1in ~r~ ~r~ bly ~r-5 for~tned by a digital mi~ro~rocs~or ( ~uoh a~; part numb~rDSP56001 mad~ by Motorola) ~ rating under ~o~tw~re oon-trol . It woul~ b~ cl~ar to one- oi~ c: rd~ nary ~clll in th~
art, after por~;al o~ th~ sp~ laa~ion, ~rawin~s and claim:3 her~in, th~ pro~rammin~ andard digital ~icro-10 proces~or tel p~ar~orm signal g~n,~ration ~n~ nal manlpu-lation a~ de~rib~d her~in woul~ b~ a strai~htforward te~k and would not requir~ undue axp~rim~nta'cion.
I~ would be clear ~o one o~ o:~dinary ~kill in the ar~, a~t~r perusal o th~ ~pe~i~ic~tlon, clr~wirl~s and 15 claims her~in, that the in-~nt:ion m~y bs ciombinod wl~h known methoda o~ aomputing ~lood oxy~erl con~ riation i~nd other blood ~a~ valu~6 from ths d ta ou~E~u~ nale 110 which ar~3 produa~d. Providing a sy~m which aom~in~s ~he inventlon with ~ut~h }cnown me'cho~ ould b~ ~ ~tralght;for-~0 wiard task, ~or peru~al o~ ~ho ~3pe~ d~0n, drawin~;and ~laims h-rein, and woul :I not ro~uir~ undu~
~xper im~n~at 1on .
In a pr~erred ~ml3odiment, the ~ir~t :eilter 204 and ~he s~cond fil~r 2~6 ~hould ~i~Ch 3xhibit 2. lcnown phas~
S response . Otherwi~ pna~ error~ mlght intro~uc E3 oros~-ta1k b2twe~n ~ho in~ar~d and r~d data ou~pu~ ~ignal~ llO.
Whil~ ~r~ rr~d ~mbodimont~ ~red di~olo~cl harl3in, many VariRtiOn~ ar~3 pos~ibl~ wh~ h romair, with ~ n tne oon-30 c~p~ and 300pll~ 0~ thQ inv~nti~7n~ 8ndl ~h~ variation~woul~ b~a~ome cl~ar to on~ o~ or~linary ~klll in th~ ar~
a~ter perusal ~ the ~p~ci:ei¢~ion, drawing~ and Gl~im~
h~r~in .
It iE~ w~ll known in thl3 art ~o ~oll~ot pho~o-plethysmographic data 6~imultanllao~ y ~t e~ ural-ity of en~rgy ~avel~n~h~. For ~axampls, blood oxygon conc~n-o tration may ba m~asur~d by do~e~mining ab~orption by apa~ien~ ~ ~ ti~u~ on in~rarsd and r~d ll~h~: ~ t21e degr~
o~ absorpti4n i~ ~ypl~ally ~ ront ~or th~0e two wav~-lengtho. In~rar~ And rsd llç~t ~r~ ~mitt~ lnto thæ
patiant ' ~ ti~aue~ (~ . g ~, by infri~r~ and r~ EDs) and ~ho 15 total energy rec~ived to b~ d~t~ d by a ~in~le d~tector (e . g., a p~otod~odo~ . How~v~r, on~ pro~l~m i~ th~t t~
signal produaad by th~ ~e~ctor mu~c b~ prs~ ed to separa~ ~he infrar2d and re~ por~ions ~rom each othe~.
on~ m~thod o~ th~ prior ~r~ ;h~wn ir~ ~. S . P~tent 20 No. 4, 407, 290. Tima-divi~ion multiplexing i~ u~d to al~ornat~ly 3witch on the ini~ar~d and r~d ~mitt3r~, ak a fr~quency great~r than the pati~nt~ pulo~ ~te. Tha dete¢tor ~ign~ then s~parat~d into lll~r~red and ræd portion~ by ~ampling in ~ynchr~ny with th~ on/o~f ~w~ t~h-2g ing of th~ in~rar~ and r~d emittera.
Whil~ t~is3 m~khod ~ucce~sPu~ ly ~parat~ th~ in~rar~dand red portion~, it q~n~r~lly r~aquire~ that slamplinçl th~
d~te~tor ~i~nal mu~t b~ ~ynchros~ 3d wlth the on~o~
~awitching of ~e in~rar~d and r~d ~mittero. It i~ al60 30 di~fi~ult ~hile u~ing this m~thod ~o ~omp&nsa ~ for nois3 :
:
MAR 3 ~ î 09 ~ 3~7 i3 p ~/36 ~ources ~uah a~ an~içnt liç~h~ and ~l~ctrom~n~tia int~r~r~nco ~
A ~3cond m~thod o ~ prior ar~ hown in u. 5 .
Pakant No. 4, ~oo, 885. Thc~ in~rar~d ~nd red amitt~r~ ar~
5 ~riv~n at two di~f~3rent ~r~quonc~ s . Th~ d~t~ctor . ign~l i5 then sep~a~ed into tn~rar~d an~ r~ portiono by tet~ing a~ thos~ two dl~or~nt ~equ~n~
While ~hi~ me~h~d E;uc~e~u.lly ~pa~at~ th~ in~rare~
and red portions, the m~thod d~sc:rlb0d in ~h~ patent lo requir~ demultiploxin~ nals whiah are phaæ~-synchronized with the Inultipl~x:Lng freqll~noi i3~, An~ pro-duces a high~r pow~r output t-ha~ th~ ~im~-divi~ion mulki-plexing ~nethod. Al~o, whll~3 th:i& ml3thod m~ avold noi~
sou~ce~ at pr~d~t~rmin~d and X:nown ~r~quRalci~a, it i~
15 di~ioult to ~omp~n at~ ~or noi~ sourc~ whic~h wor~ not kno~n be~ore ~h~ multiplexing ~r~uencis~ w~r4 ~o~an, particularly b~scaus~ two sepa~ate ~r~qu~ncie~ which ar~a fre~ of i~t~3r~r6~n4e mus~ ~ ho~n.
Su~ ~y Q~, ~o The invQnkion provi~f~s a m~hod o~ pho~opl~khysmo~
graphiç:~ by phas~ division multiplexing (as d~s~in~d herein) arld d~mul~iplexing o~ ~ign~l s Sor in~rar~d and red a~sorpl:ion o~ bloo~. Flrst and s~aond ~arri6~r ~iqnalç, dis~.ing~ a)~le by ~ha~a, ~r~ re~p~a~iv~ly appli~d to 25 ~ n~rared and r~3d on~rgy ~mittor~ o~ rec~lv~ th3 sum of the ~nar~y a~t~r mo~ul~tio.n at th~ in~rar~d a~d re~d w~valengkh~. Th~ ~ignal rec~iv0d by tl~ d~l:æctor 1~ th~r damultipl~xe~d lnt~ i'C5 original ~lr~t ~nd ~cond comp3~
n~nts, th~r~by allowin9 ~t~rmin:in~ o bo~h ~h~ in~rarod 30 and rad modulatlon component~.
In A p~err~d ~mbodim~n'c, ~h~ ~irst and ~econd car-rler signals may ~ompri$6t tim~ axyins~ p~ariodio signal~
wi~h identical ~xequenoy and ~r~uency ~i;p~tra, ~Lueh a~ a palr of ~ine wav~s ~Ynich ar~ in~l~.stingui~habl~ xcspt by 35 pha~e ~nd ampli~ud~. ~ 90~ ph~e ~ rence i~ prsferr~d, but any phase oth~r th~n o or an :int~g~ar multlpl~ of 180U
i .
MAR; ~ 2 0 ~ 7 ,1~ P 7/30 i~ workabl~. Al~o, a aarri~r ~r~qu~ncy which ~void~
exce~ive int0rforenae ~rom ambi~nt light i~ pxæ~red, such a~ 3 0 H2 .
5Figure 1 show~ a blocX di~ am oP a p~lo~opl~thysmo-graphic system c:ompri3ing an o~n~odim~nt or th~ inv~ntion.
Figure 2 ehow~; a blook ~liagr~lm Or 'ch~ pha~-divi~ion znultipl6~xer and d~mul~ipl~x~r ~ an #~mbodiment. Or the ~nvention .
10 ~
~ n em~odim~nt o~ ~hl~ in-r~n~ion m~y be u~ed to~e~r with inv~ntions whioh ar~ ~is~103~d in ~ ~:op~nding appli-c~tion titlsd "P~OTOPLETHYSMO~ PHICS tJgING EIIE~GY-REDUCINC; WAVEF~RM S~APINGI~, application S~rial No.
15 Lyon & ~yorl ~oa~et No. 191~23~, Pil~d th~ ~uq~ ~Ay in th~
nam~ o~ tho 8t~ nY~nltors, her~ y in~ rpora . ~d by r~r-ence a~ if ~ully a~t ~orth h~r~in.
Figure 1 ohows a bloo~ diagram o~ ~ p~o~opl~thysmo-graphic sys em aomprising an sm~odimen~ o~ t~e inv~ntion.
~oA plurality of ena~0y ~mitte~ 101 m~y ~ach bs t~n~d to a separate w~ ngth. In ~ p~`err~d ~bodim~nt ~or maasuring hlood oxyq~n, on~ o~ th~ ~mit~or~ 101 may co~0 pris~ an inX~r~d light emi~r and m~y op~r~t~ at a wav~-length o~ about 880 nan~m~ter~ nother on~ o~ the ~mit-~5 ters 101 may compriæ~ a r~d li~ht emit~er ~nd m~y o~rat~
at rl wa~elengt~ o~ abou~ 6~6 n~nom~t~r~ s u~ad he~in, "light" refers to el~atromagn~tic ~nergy of any w~v~-length, wh~thqr vi~ or not.) ~owev~r, it may ocour that o~h~ w~v~l~nyths m~y ~o u~ ul, ~uch ~ ~or maa~ur ing blood ~arbon dioxid~, blood car~on monoxld~, oth~r blood ya~ conc~ntrations, ~lood ~luco~, or moro gan~
ally, ot~er ch~miaal and/~r phy~ l Qono~tration~.
In a pr~ferred ~m~odim~nt, ~,ach o~ th~ emit~rh 101 may oo~pxl~ an LE~ ~uch aa p~rt n~mb~r 0~-8803 mada by Marktech Int~rnational ¢orp. ~or ~h~ infrar~d LED and part ,:
~ ~ ~ 2 2 I ~ P 8/3~
MAR; ~ '~ 19: lu number M~1500-PUR ~nadq by Mark~q~c~l Int~srn~lonal ~orp. Por the rqd LED), a~ ~ ~ w~ll 3cnown 1n ~ho art, ~nd may bo coupl~d by m~an~ o~ an ~ED drl~lror 102, ~3 ia well known in the art, ~o a carrisr ou~put 103 oi~ a muxf~mux alroui~
S 104 (~Qa ~igur~ 2~.
~ n~r~y :erom ~ omit~r~ 10 'I ls ~ppl 1 ~d ~o ~ t i91;~U~a saction 105 Or a pationt . In ~ pr~ærr~d. 02Rb4d.im~nt 20r mea~urin~ bloc~d oxyg~n, th~ t~e~lu~ a~ion lOS i~ pre~
~ bly cho~erl ~uc~h ~ha~ ~nfargy from tho ~mlt~,lDrs~ 101 pa~3~
lO through the patieht~ blood v~s~ , sauch a~ an ~nd o~ ths patient~ ~inger, ~he patier~ arlob~, or ~or n~onat~a) the pa~ nt ' g hahd ot ~oot ~ Th~ U~ tion lOS may modul~te the ~n~3rgy r~rom the ahli~t~3r~; lol, ~g i~
known in the art , ~ . g ., by abso~king ~om~ o~ th~ qnQrgy at 15 ~ach wavolength~ Typi~ally, ~n~3r~y ntay be modulate~i by tran~mi~ion throug~ ~h~ tisou~ ~ec~ion 105, but it may occur that enar~y may ~ ~nodula od by r~ otion o~ by othar Inaans~ . ...
A d~tootox 106 rec~iv~3 ~nergy a~t~r modulAt~ on by 20 the ti~su~ ~3cti on 105 and genl~rat~ n output ~l~n~l whicll in~icat~as th~a ~otal ~n~y r~c~iv~d. In & pr~rr~d embodiment, th~ ~etector 10~ ma!f comprisa a phot~diode ch aB par~ num~er OSI-1140 madl~ by opto S~nsor~, In~. ) as i~ w~311 lcnown ln ` ~-h~ a~ . A-~ ou~put o th~ d~tector 25 106 iB ampli~i~d by an ~mplifi~r :L07 and c:ouplq~ y m6lan~
of a filter 108 to a ~te~or input lns of the mux~d~mux c:lrcuit 104.
l'h~ muxjd~mux circult 104 gen~ra~eæ a ~ata ou~put eign~l 110 at a data. output 111, for oac~h anergy wa~
30 longt}l, whlch indiaat~s th~ modulation whlr!h th~ ti~uo se~tion 105 ~pplied to ~h~t ~n~:rgy w~ ngth. In a pr~Pferr~3d ernbodlm~n~ ~or me~uring blood oxyg~n, in~eo~
mation ~uch a~ blood oxyg~n oon~n~ration may b~ ~al~u~
lated from tllo output aign~l, as i~ woll known in th~ ~rt.
MAR;3 ' ~'~ 13~ P. 9/3 Pha~ li~s~
P~ase-divi~;ion multipl~xi~g~ as u~d h~r~
d~fin~d a3 follow~. In ~ a~ .lviE~ion ~ultipl~xing, ~
pl-~ral ity Or ~arrier ~i~fnals ~1ria :son~truct~d, ~ch or which may compris~ a mixt~r~ oi~ ~arrl~ ompon~nt0, and which ~re di~tin~uis~2~ablo by pha~ In a~ re~ i3rred ~m}:odlment, ~h~ carri~r sl~nal~ ~re i~en~ l ex~e,~t ~or p~se.~ h carrier ~gnal may ~:~ s~par~t~ly modula~d, an~ the r~sultants ~um~d. ~'h~r~d~t~r, th~ ~p~rat~
modulations may be ret::over~d fr~Dm th~ Sum, a~ di~lo~d herein .
In A pr~rr~d ~mbodiment, ~ f ir~ carrl~r ~ may comprise a slne wav~, e.g., ~o~ (2~ , and a o~cond ca~ri~r ,~ may oompri~ ~ sin~ wa~ w~ioh i~ pha~e-ahi~
~ith r~pect t~ th~ ~ir~t carrier, ~ in ~ 2~r ~l t) .
Alt~rnativ~ly, th~ ~irst oarri~r ~ may ~om~ri~ um o~
two ox mora ~arri6~r c:omponant6, ~.~., co~ (2~ fl t) ~ eos ( 27r f 2 ~), an~ tne second ~arri~ ~1 may as~mpri~e ~ 63urn, of two or mo~e c~arrier oompona~nt~ which is dl~tinguish~
from 'che ~iræk o~rri~3r by ph~ -, co~ ~2~ ~l t ~
+ co~ t2~T ~2 t ~ ~). Po~ibly, iE~ may c:ompris~ a h~r-monlc of ~l, but thi~ is not r~quir~.
The following ~elakion~ de~cribç~ s~epa:r~te modulation of each c~rri~r ~ignal, with a 90~ p~a~ dl~3r~nc~:
~ ~ co~ ~w t) (1~2) in (w t~ 1ll3) o - ml ~ + m2 ,~ (114) where w i ~ a c~rri~r freslu~ncy~ ml i~ ~ f`irst modu-lating ~f~c~ ~a. ~., at An in~ r~d wav*langth); m2 i~ a second m4dulating ~ff~c~ ~.5t" at a r~d w~va l~ns7th) ~ ~nd ~ doteate~d ~um o~ hs~ mo~lllat~sd çarri~r ~ign,s.l~
The d~toct~d ~u~n ~ is separat~ly multipli~cl by twic~
the f irst carrl~r ~ an~ ~y t~ia~ the ~econd c~rier ~:
~ ct o ~ ml ~ ml ~o~ ~ w ~) ~ m2 ~in t2 w ~) (115) 2 ~ n2 - m2 ao~ (~ w t) ~ ml ~in (2 ~ 116) P, 10/3 MA~, .3 `'`~ 19 1 1 Thos~ p~oduc~ a an~ a ~o ~iltere~d ~o ro~ov~r ml ancl ~
T~e following r~latlons dQ~rib~ ~opara'ce modLlla~ion o~ eaa~ c~rri~r signal, with ~ p~la~ dii~f~ nce oth~r th~n 5 90~:
C~ 3 C08 (W 't) 1117) ,~ ~ oos (w ~ i- ml ~ ~ m2 ,~
whera ~ h~ carrier ~requ~3ncy ~ mî i~ th~ t mod~ ting ~ t (~ t an in~rar~d wqvllalongth~ 7 m2 is ~e s~c:ond ~nodulatillg ~:efq-c~t ~ t ~ ~ed w~velength): and o i~ tha d~t~t~ um o~ ~he modu-lated c~rri~ar ~i~nal~ ~, a The det~cted ~um o i~ Popara~t~ly multlpli~d .by twlce 15 the rirst aarri~3r ~ and by twic6~ ths socond ca~rier ~:
2 ~x ~ = ml ~ ml cc1O ( 2 w t~ ~ m2 coaa (~) ~
m2 CoB (~ w t ~ ~p) (120) o = m2 ~ 3n2 ~o~; ( 2 w t ~ ml co~
ml ~ w t + ~ (121) ~o Theo~ pro~ucts 2 a and 2 ~ ,B 8~ llt~t~d t raoovar ml* and m2*.
ml* ~ ml ~ m2 oo~) (122) m2* ~ rnl 005(~) + m2 (123) or [ ] [ ] ~ ~ ] (124) co~ 1 n12 m2 or li; M ~ 1 * (7 25) whe~r~ X i a phaS~e-dep~n~n~ rnatrix ~ ~howns ~ i~ a vector o~ ~odulation e~f6~c~s ml, m~; and N~ i~ a v~o-tor oP mo~ulated oarri~r ~ompon~3nt partA ml~ 2~
Separate ~ompon~nt~ ml, m2 may b~ demultipl~X~d by multip~ ying by ~h~ left multlplic;a~ive inversæ of tho 35 pha~e-dep~nq~n~ ~n~tri~ ISt M ~ b ( 1 2 6 3 ~r ~5 = X 1 X ~5 ( 127 MAR, 3 ~ 12 20$~ P, 11/36 ~i Figure 2 ~3hs:w~ a ~loq~ dl~r~m s~ ~h~ phaEI~-dlvioion mul~ipl~x~r an~l do~hul~lpl~xBr 0~ e~r~ e3m~0di2n~n'c o~ th~
in~ention .
Th~3 di~3clo~ure hi3rein ~howsl ~ CA~i3e3 who~ b~th th~
f irst oarri~r and th~ ~cond ~;~rri~r ~ach comprl~ pur~
~ine waV1~9 W2~iC~ dl~r ill p~as6~ by ~x~tly ~0~. ~owq~ver, applying this ~i ~lo~ure t~ ca.3~ r~ ~lth~r ~h~ ~ir~
or tha se~ond carrler i~ n~t a Elure sin~ wav~, or ~h~re a 10 componen~ o~ ~ho ~irst and ~ ond carrier~ ef~r in pha~:o ~y oth~r than Qxac~ly 90~ would b~a c~ear to one o~
ordinary 5Xill in ~e art, af~3r peru~3al Or thQ sp~ci~ica-tion, drawings and cl i;n~ ~e~in.
A o~arrier generatc)r 201 qenera~l3 a plurality o~ car-15 rier ~ignals 202. ~n a pref~rrad ~mbodim~nt, taa~h carri~rsign~l 202 i~ alloc~t~ ko one ~mitk~r wavel~rtgth. Thu~, ther~ st carrier si~nal .202 alloaat~d to ini~r~r~d and a ~cond ca~ri~r si~n~l 202 alloa~d to r~d. ~l~o, ln a pr~rre~ odimsn~, each oarri~r sign~l 20~ may 20 oo~prise ~ sine w~v~ with ~re~oncy fl, a~ di~c103~d herein, and th~ two car~ier ~it~nal~ ~0~ y di~r in pha ~e by exactly ~ o ~ .
In a p~err~ad embodim~nt, ~ cho~an such that intarfar~nGa ~ro~n noise ~ourc~ uoh a~ ~mbi~nt light and eleo~romagne~l~ int~r~ll3r~n~e, i~ minimi~OEd. In ~ pr~-ferred embo~imant, Pl i~ al~o ~ho~en ~uch ~hat ~ b~ndwidth o~ ahout 4 H~ ~or the modulatin~ 3~fec~ o~ th~ tis~
section 105 i~ ~llow~d. Fr~uenol~ in t~e r~ng~ o~ a~o~t ~0-40 H&, suGh a~ 31.5 Hz, are pr~f~rr~d, but it would alaar to on~ o~ ordlnary skill irl the art, A~t~r p~ru~l of th~ ~p~ ic~ti~n, drawing~ ~In~ clalm~ h~rain, th~t other fr~qu~ncle~i wo~ld be work~bl~, and are within th~
~cop~ and ~pirit o~ the inv~rltion.
I~ w~uld aleo be cl~ar ko on~ o~ ordinarY ~kill in ~5 the ar~, a~ter paru~al ~E the ~ai~i~a~ion, drawing~ and clai~ns ller~in, that there i~ no rq~quirom~3nt ~hat the aom pon~nt~ o ~.h~ c:~rri~r sign~l ~02 mu~t b~ ~ine wav~o.
:
, ~ :
. ~ ~
.
MA~, ~'h' 19:13 2~2Yi~ P,12/36 Other ~yp~ of aarri~r oom~on~nt~ ;uoh a~ ~qu~re wav~ or oth~r wav~orms, would ~ wor:k~bl~, ~nd ~r~ withln the ~aope and . pirit of th~ inv~ntion~
It would 1:~13 oloax to on0 4~ o~llnary ~klll in th~
5 art, af~r E~eru~al o~ th~ s~c~ ~iaation, d~wing~ ~nd claim~ her~in, thAt there is no r~auir~ment th~t ths ~ir~3t aarriQr and th~ ~cond c~ r~i~r ~n~u~ di~r in ph~3l3 ~Dy ~xactly 9o'. CJth~r phaE~s~ di~33r~ oth~r thar3 0 or an inte~r mul~iple of l~O~ would be worka~l~, and ar~ w~ in lO ~he 8aOp~ and ~pirit P4 th~ invQntion.
It would al~o ba ol~aar to on~ o~ ordinary ~Xill in the art, a~ter peru~al o~ the e~ai~ic:A~ion~ drawing~ ~nd claims h~r~in, t}la~ th~ ~nv~an~ n m~y b~ ~d~p~d to measurement of oth~r oon3tltuo:nt~, s;u~h a~ blood ~:Arbon 15 dloxid~, bls~od o~rbon monoxid~, oth~r bloc~d g~ ao2~c~n-trationE~, blood gluqosQ, or mor~, ~9nlarally, oth~r ah~mic:~l and/or phy~ical 40ncan~r~tion~.
Eaah carri~r signal 202 :L~ ooupl~ad ~y ml3an$ 4f bri~htnc ~ amplifi~sr 203, ~or adju~ttn~ tho ~rightn~ o~
20 a corr~6pondin~ ~mitt~r lOl, ~ th~ ~orr~pond~ng o~rri~r output 103 oP ~he mux~d~mux cir3uit 104.
~ h~ d~tacto~ input lO~ ooupl~d, by m~an~ o~
first ~ilter 20~, for r~moving sompon~ntæ at ~r~ enc:is~
oth~r thar. the c~rri~r ~r~aquenGy, t~ ~a plurAlity o~ d~mul-25 tiplexor 21~:m~nt8 205 for d2m~l~ipls~xin~ ~ha modulatadfirst c~rrier s:ignal 20a ~rom th~ m~dulat~d ~saond carri~r signal ~ 02 . A oeo~nd input o~ C~ oi~ ~h~ d~multi~l~x~r ~l~ments 205 ill ooupl~d to on~ o~ th~ ~arrl~r oiçln~l~ 20~.
Th~3 carrier ai~nals 202 ar~ mul~ipliq~, and th~ pxo~uctæ
30 ar~ coup~sd, by m~an~ o~ ~ ~e3cond ~llt~r ~û~, fo~ r~movin~
compone,ntæ o~h~r ~han ba~band"~hlo~ ~how~ ths modulating ef ~ec~ o~ th~ ti~u~ tion 105, ~o producl3 thla data ou~pu~ nal ~ l l O .
The data oll~pUt ~ nal~ llO ~ach indi;:at~ ~h~3 mo~ula-35 tion ~ ct ~or the cor~pondlng carri~r ~ignal 202, a~multiplied by ~ oorr~ ion by l~h~ corr~Gponding b~igh~nes3 amplifier ~03. ~aah da~a outpu~ ~ignal llO i~ ~oupl~d ~o 4R; 3'g~ 19 13 2t~2~J P I~/30 th~ corr~sponding da~A ou~u~ l~.l o~ ~h~ mux/d~mux clrcult 104 .
In a pr~f~rr~d ~m:bo~imont, ~ n~l g~nar~tion and ~iy-n~l manipula~lon as d~cribad h~re1in ~r~ ~r~ bly ~r-5 for~tned by a digital mi~ro~rocs~or ( ~uoh a~; part numb~rDSP56001 mad~ by Motorola) ~ rating under ~o~tw~re oon-trol . It woul~ b~ cl~ar to one- oi~ c: rd~ nary ~clll in th~
art, after por~;al o~ th~ sp~ laa~ion, ~rawin~s and claim:3 her~in, th~ pro~rammin~ andard digital ~icro-10 proces~or tel p~ar~orm signal g~n,~ration ~n~ nal manlpu-lation a~ de~rib~d her~in woul~ b~ a strai~htforward te~k and would not requir~ undue axp~rim~nta'cion.
I~ would be clear ~o one o~ o:~dinary ~kill in the ar~, a~t~r perusal o th~ ~pe~i~ic~tlon, clr~wirl~s and 15 claims her~in, that the in-~nt:ion m~y bs ciombinod wl~h known methoda o~ aomputing ~lood oxy~erl con~ riation i~nd other blood ~a~ valu~6 from ths d ta ou~E~u~ nale 110 which ar~3 produa~d. Providing a sy~m which aom~in~s ~he inventlon with ~ut~h }cnown me'cho~ ould b~ ~ ~tralght;for-~0 wiard task, ~or peru~al o~ ~ho ~3pe~ d~0n, drawin~;and ~laims h-rein, and woul :I not ro~uir~ undu~
~xper im~n~at 1on .
In a pr~erred ~ml3odiment, the ~ir~t :eilter 204 and ~he s~cond fil~r 2~6 ~hould ~i~Ch 3xhibit 2. lcnown phas~
S response . Otherwi~ pna~ error~ mlght intro~uc E3 oros~-ta1k b2twe~n ~ho in~ar~d and r~d data ou~pu~ ~ignal~ llO.
Whil~ ~r~ rr~d ~mbodimont~ ~red di~olo~cl harl3in, many VariRtiOn~ ar~3 pos~ibl~ wh~ h romair, with ~ n tne oon-30 c~p~ and 300pll~ 0~ thQ inv~nti~7n~ 8ndl ~h~ variation~woul~ b~a~ome cl~ar to on~ o~ or~linary ~klll in th~ ar~
a~ter perusal ~ the ~p~ci:ei¢~ion, drawing~ and Gl~im~
h~r~in .
Claims (52)
1. An instrument for evaluating the concentration of a constituent in an object by measuring the transmis-sion of light of two wavelengths therethrough, comprising;
(a) first and second light emitters which emit lights at respective, first and second different wave-lengths;
(b) a modulator/driver to drive the light emitters with respective first and second carriers which vary as a function of time, the carriers being of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) a detector to receive light from the first and second light emitters after it has passed through the object, and generate a resulting detector signal carrying information relating to transmission of the object at both wavelengths;
(d) a demodulator which generates from the detector signal, in a first channel, a first demodulated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more carrier modulated components, and, in a second chan-nel, a second demodulated signal which is a sum of a com-ponent proportional to the object's transmission at the second wavelength and one or more carrier modulated com-ponents; and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
(a) first and second light emitters which emit lights at respective, first and second different wave-lengths;
(b) a modulator/driver to drive the light emitters with respective first and second carriers which vary as a function of time, the carriers being of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) a detector to receive light from the first and second light emitters after it has passed through the object, and generate a resulting detector signal carrying information relating to transmission of the object at both wavelengths;
(d) a demodulator which generates from the detector signal, in a first channel, a first demodulated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more carrier modulated components, and, in a second chan-nel, a second demodulated signal which is a sum of a com-ponent proportional to the object's transmission at the second wavelength and one or more carrier modulated com-ponents; and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
2. An instrument for evaluating the concentration of a constituent in an object by measuring the transmis-sion of light of two wavelengths therethrough, comprising;
(a) first and second light emitters to emit light at respective, first and second different wave-lengths;
(b) a modulator/driver to drive the light emit-ters with respective First and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than O and other than an integer multiple Of l80°;
(c) a detector for receiving light from the first and second light emitters after it has passed through the object and generating a resulting detectors signal carrying information relating to transmission of the object at both wavelength;
d) a demodulator which, in a first channel, multiplies the detector signal with a sinusiodal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more carrier modulated components, and which, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generates second demodulated signal which is a sum of a component proportional to the objet's transmission a the second wavelength and one or more carrier modulated compo-nents; and (e) a demodulated signal filter which for out carrier modulated components of the signals from the first and second channels.
(a) first and second light emitters to emit light at respective, first and second different wave-lengths;
(b) a modulator/driver to drive the light emit-ters with respective First and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than O and other than an integer multiple Of l80°;
(c) a detector for receiving light from the first and second light emitters after it has passed through the object and generating a resulting detectors signal carrying information relating to transmission of the object at both wavelength;
d) a demodulator which, in a first channel, multiplies the detector signal with a sinusiodal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more carrier modulated components, and which, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generates second demodulated signal which is a sum of a component proportional to the objet's transmission a the second wavelength and one or more carrier modulated compo-nents; and (e) a demodulated signal filter which for out carrier modulated components of the signals from the first and second channels.
3. An instrument for evaluating the concentration of a constituent in a body structure by measuring the transmission of light of two wavelengths therethrough, comprising;
( a ) first and second light emitters to emit light at respective first and second different wave-lengths;
(b) a modulator/driver to drive the light emit-ters with respective first and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) detector for receiving light from the first and second light emitters after it has passed through the structure, and generating a resulting detector signal carrying information relating to transmission of the structure at both wavelengths;
(d) a demodulator which, in a first channel, multiples the detector signal with a sinusoidal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the structure's transmission at the first wavelength and one or more carrier modulated components, and, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generate a second demodulated signal which is a sum of a component proportional to the structure's transmission at the second wavelength and one or more carrier modulated components;
and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
( a ) first and second light emitters to emit light at respective first and second different wave-lengths;
(b) a modulator/driver to drive the light emit-ters with respective first and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) detector for receiving light from the first and second light emitters after it has passed through the structure, and generating a resulting detector signal carrying information relating to transmission of the structure at both wavelengths;
(d) a demodulator which, in a first channel, multiples the detector signal with a sinusoidal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the structure's transmission at the first wavelength and one or more carrier modulated components, and, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generate a second demodulated signal which is a sum of a component proportional to the structure's transmission at the second wavelength and one or more carrier modulated components;
and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
4. An instrument as defined in claim 1 or 2 or 3, additionally comprising a detector filter to filter fre-quencies other than around the carrier frequency from the detector signal prior to it being processed by the demodulator.
5. An instrument as defined in claim 3 wherein the carrier frequency is greater than the bandwidth of the object's transmission signal.
6. A pulse oximeter for evaluating the concentra-tion of oxygen in a body structure by measuring the trans-mission of light of two wavelengths therethrough, comprising;
5. An (a) first and second light emitters to emit light at a respective, first and second different wave-lengths;
(b) a modulator/driver to drive the emit-ters with respective first and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) a detector for receiving light from the first and second light emitters after it has passed through the structure, and generating a resulting detector signal carrying information relating to transmission of the structure at both wavelengths;
(d) a demodulator which, in a first channel, multiplies the detector signal with a sinusoidal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the structure's transmission at the first wavelength and one or more carrier modulated components, and, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generate a second demodulated signal which is a sum of a component proportional to the structure's transmission at the second wavelength and one or more carrier modulated components;
and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
5. An (a) first and second light emitters to emit light at a respective, first and second different wave-lengths;
(b) a modulator/driver to drive the emit-ters with respective first and second sinusoidal carriers which are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(c) a detector for receiving light from the first and second light emitters after it has passed through the structure, and generating a resulting detector signal carrying information relating to transmission of the structure at both wavelengths;
(d) a demodulator which, in a first channel, multiplies the detector signal with a sinusoidal signal in phase with the first carrier to generate a first demodu-lated signal which is a sum of a component proportional to the structure's transmission at the first wavelength and one or more carrier modulated components, and, in a second channel, multiplies the detector signal with a sinusoidal signal in phase with the second carrier to generate a second demodulated signal which is a sum of a component proportional to the structure's transmission at the second wavelength and one or more carrier modulated components;
and (e) a demodulated signal filter which filters out carrier modulated components of the signals from the first and second channels.
7. An instrument as defined in claim 6 additionally comprising a detector filter to filter frequencies other than around the carrier frequency from the detector signal prior to it being processed by the demodulator.
8. An instrument as defined in claim 6 wherein the carrier frequency is greater than the bandwidth of the object's transmission signal.
9. An instrument as defined in claim 6 or 7 or 8 wherein the demodulated signal filter is a low pass filter which filters signals above the bandwidth of the object's transmission signal.
10. An instrument as defined in claim 6 or 7 or 8 which additionally comprises an interpreter which evalu-ates the concentration of oxygen from the demodulated signal filter output,
11. A method for evaluating the concentration of a constituent in a object, comprising;
(a) driving a first and a second light emitter, which emit light at different wavelengths, with respective first and second carriers which vary as a function of time and are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(b) directing the light from the emitters through the object;
(c) receiving the light from the emitters at a detector after it has passed through the object, which detector generates a detector signal carrying information relating to transmission of the object at both wave-lengths;
(d) demodulating the detector signal to gener-ate, in a first channel, a first demodulated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more car-rier modulated components, and, in a second channel, a second demodulated signal which is a sum of a component proportional to the object's transmission at the second wavelength and one or more carrier modulated components;
and (e) filtering out carrier modulated components of the first and second demodulated signals
(a) driving a first and a second light emitter, which emit light at different wavelengths, with respective first and second carriers which vary as a function of time and are of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(b) directing the light from the emitters through the object;
(c) receiving the light from the emitters at a detector after it has passed through the object, which detector generates a detector signal carrying information relating to transmission of the object at both wave-lengths;
(d) demodulating the detector signal to gener-ate, in a first channel, a first demodulated signal which is a sum of a component proportional to the object's transmission at the first wavelength and one or more car-rier modulated components, and, in a second channel, a second demodulated signal which is a sum of a component proportional to the object's transmission at the second wavelength and one or more carrier modulated components;
and (e) filtering out carrier modulated components of the first and second demodulated signals
12. A method for evaluating the oxygen concentration in a body structure of an animal, comprising;
(a) driving a first and a second light emitter, which emit light in the red and infra-red regions, respec-tively, with respective first and second sinusoidal car-riers of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(b) directing the light from the emitters through the body structure;
(c) receiving the light from the emitters at a detector after it has passed through the body structure, which detector generates a detector signal carrying infor-mation relating to transmission of the body structure at both wavelengths;
(d) demodulating the detector signal to gener-ate, in a first channel, a first demodulated signal which is a sum of a component proportional to the body struc-ture's transmission of red light, and one or more carrier modulated components, and, in a second channel, a second demodulated signal which is a sum of a component propor-tional and one or more carrier modulated components; and (e) filtering out carrier modulated components of the first and second demodulated signals.
(a) driving a first and a second light emitter, which emit light in the red and infra-red regions, respec-tively, with respective first and second sinusoidal car-riers of the same carrier frequency and having a phase difference other than 0 and other than an integer multiple of 180°;
(b) directing the light from the emitters through the body structure;
(c) receiving the light from the emitters at a detector after it has passed through the body structure, which detector generates a detector signal carrying infor-mation relating to transmission of the body structure at both wavelengths;
(d) demodulating the detector signal to gener-ate, in a first channel, a first demodulated signal which is a sum of a component proportional to the body struc-ture's transmission of red light, and one or more carrier modulated components, and, in a second channel, a second demodulated signal which is a sum of a component propor-tional and one or more carrier modulated components; and (e) filtering out carrier modulated components of the first and second demodulated signals.
13. A method as defined in claim 11 or 12 wherein the first and second light emitters are driven with car-riers of a frequency greater than the bandwidth of the object's transmission signal.
14. A method as defined in claim 11 or 12 which additionally comprises evaluating the concentration of oxygen from the demodulated and filtered signals.
15. A device for collecting photoplethysmographic data, comprising means for generating a first and a second sig-nal, said first and second signals being distinguishable by phase;
means for applying said first and second signals to a modulating medium;
means for detecting a composite signal at an output of said modulating medium, said modulating medium having a first and a second modulating effect; and means for generating a first and a second output signal responsive to said composite signal, said first output signal indicating said first modulating effect and said second output signal indicating said second modulat-ing effect.
means for applying said first and second signals to a modulating medium;
means for detecting a composite signal at an output of said modulating medium, said modulating medium having a first and a second modulating effect; and means for generating a first and a second output signal responsive to said composite signal, said first output signal indicating said first modulating effect and said second output signal indicating said second modulat-ing effect.
16. A device as in claim 15, wherein said first and second signals are periodic time-varying signals with identical periods.
17. A device as in claim 15, wherein first and second signals have identical frequency components.
18. A device as in claim 15, wherein said means for detecting comprises a photodiode.
19. A device as in claim 15, wherein said composite signal comprises a sum of said first modulating effect applied to said first signal and said second modulating effect applied to said second signal.
20. A device as in claim 15, wherein said photo-plethysmographic data comprises blood gas data.
21. A device as in claim 15, wherein said photo-plethysmographic data comprises at least one of the group:
blood oxygen, blood carbon dioxide, blood carbon monoxide.
blood oxygen, blood carbon dioxide, blood carbon monoxide.
22. A device as in claim 15, wherein at least one of said first and second signals comprises a plurality of component signals.
23. A device as in claim 22, wherein at least one of said component signals comprises a sum of at least one of the group: a side wave, a square wave.
24. A device as in claim 15, wherein said means for applying comprises a plurality of light-emitters.
25. A device as in claim 15, wherein said means for applying comprises a plurality of light-emitters tuned to a plurality of wavelengths.
26. A device as in claim 15, wherein said modulating medium comprises animal tissue.
27. A device as in claim 15, wherein said modulating medium comprises at least one of the group: blood, blood vessels, bone marrow, ligament, muscle, skin.
28. A device as in claim 15, wherein at least one of said modulating effects comprises amplitude modulation.
29. A device as in claim 15, wherein said modulating effects comprise an amplitude modulation effect which varies with energy wavelength.
30. A device as in claim 15, wherein at least one of said modulating effects comprises a time-varying component.
31. A device as in claim 15, wherein at least one of said modulating effects comprises a time-varying component which is correlated with a biological process.
32. A device as in claim 15, wherein at least one of said modulating effects comprises at least one transmis-sion response of a modulating medium.
33. A device for collecting photolethysmographic data, comprising means for phase-division multiplexing a plural-ity of modulating signals; and means for phase-division demultiplexing said plurality of signals.
34. A device as in claim 33, wherein said plurality of modulating signals comprises an infrared wavelength modulating signal and a red wavelength modulating signal.
35. A device as in claim 33, wherein said means for phase-division multiplexing and said means for phase-division demultiplexing collectively comprise a plurality of carrier signals.;
36. A method of collecting photoletysmographic data, comprising the steps of generating a first and a second signal, said first and second signals being distinguishable by phase;
applying said first and second signals to a modulating medium;
detecting a composite signal at an output of said modulating medium, said modulating medium having a first and a second modulating effect; and generating a first and a second output signal responsive to said composite signal, said first output signal indicating said first modulating effect and said second output signal indicating said second modulating effect.
applying said first and second signals to a modulating medium;
detecting a composite signal at an output of said modulating medium, said modulating medium having a first and a second modulating effect; and generating a first and a second output signal responsive to said composite signal, said first output signal indicating said first modulating effect and said second output signal indicating said second modulating effect.
37. A method as in claim 36, wherein said first and second signals are periodic time-varying signals with identical periods.
38. A method as in claim 36, wherein said first and second signals have identical frequency components.
39. A method as in claim 36, wherein said modulating medium comprises animal tissue.
40. A method as in claim 36, wherein said modulating medium comprises at least one of the group: blood, blood vessels, bone marrow, ligament, muscle, skin.
41. A method as in claim 36, wherein said composite signal comprises a sum of said first modulating effect applied to said first signal and said second modulating effect applied to said second signal.
42. A method as in claim 36, wherein said photo-plethysmographic data comprises blood gas data.
43. A method as in claim 36, wherein said photo-plethysmographic data, comprises at least one of the group:
blood oxygen, blood carbon dioxide, blood carbon monoxide.
blood oxygen, blood carbon dioxide, blood carbon monoxide.
44. A method as in claim 36, wherein at least one of said first and second signals comprises a plurality of component signals.
45. A method as in claim 44, wherein at least one of said component signals comprises a sum of at least one of the group: a side wave, a square wave.
46. A method as in claim 36, wherein at least one of said modulating effects comprises amplitude modulation.
~o
~o
47. A m;3~hod a~ in cl~im 16, wn~r~ln said modul~ln ef~ct~ compri3~ an ~mplitud~ ~nodulation ~ ct whia~
varie~ wi~h ~n~rgy waval~n~th.
varie~ wi~h ~n~rgy waval~n~th.
4a. A mQthod a~ in al~im 3~, wh~r~in t l~a~t ~ o~
sai~ modul~ing eff~ct~ com~r~ time-v~rying compon~nt .
sai~ modul~ing eff~ct~ com~r~ time-v~rying compon~nt .
4~. A ma~hod as in alaim 3~, wher~in at 13-a~3t on~ o~
said n~odulating ~f~cts aompri~3~,3 a t~m~-varylng compon~nt whiah i~ corr~la~d wi~h a blolo~iaal pro~
said n~odulating ~f~cts aompri~3~,3 a t~m~-varylng compon~nt whiah i~ corr~la~d wi~h a blolo~iaal pro~
50. A m~tllod a~ in ~laim 3~ h~r~in ak l~t onæ o~
s~id modula~ing ef ~ot~ Qompri3es elk l~a~t on~ tran~mi~-3ion r~6pDnl~l~ 0~ a modulatinc~ madiun).
s~id modula~ing ef ~ot~ Qompri3es elk l~a~t on~ tran~mi~-3ion r~6pDnl~l~ 0~ a modulatinc~ madiun).
51. A me~hod o oc~ll2¢tin~ photo2~ thYsmOgralphio ~a~a, co~nprisi ng ~he s~p~ o~
pha~ ivl~lon mul i~l~3xlng a plur~ y oP mo~u-la~ing signal~ ~ an~
pha~o-divi~ion ~multiplexing ~aLid plurallty of ~iqnals .
pha~ ivl~lon mul i~l~3xlng a plur~ y oP mo~u-la~ing signal~ ~ an~
pha~o-divi~ion ~multiplexing ~aLid plurallty of ~iqnals .
52, ~ mq~tho~ ao in claim ~1, w~r~in ~41d ~lurallty of modulatln~ nal$ aompri~ an inrr~r~d wavel~ngtn modulatlny si~nal an~ a r~d wav~lon~h modulatin~ Di~nal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/665,594 | 1991-03-05 | ||
| US07/665,594 US5349952A (en) | 1991-03-05 | 1991-03-05 | Photoplethysmographics using phase-division multiplexing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2062270A1 true CA2062270A1 (en) | 1992-09-06 |
Family
ID=24670738
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002062270A Abandoned CA2062270A1 (en) | 1991-03-05 | 1992-03-04 | Photoplethysmographics using phase-division multiplexing |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5349952A (en) |
| EP (1) | EP0502717B1 (en) |
| CA (1) | CA2062270A1 (en) |
| DE (1) | DE69220520D1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4653498A (en) * | 1982-09-13 | 1987-03-31 | Nellcor Incorporated | Pulse oximeter monitor |
| JPS6365845A (en) * | 1986-09-05 | 1988-03-24 | ミノルタ株式会社 | Oximeter apparatus |
| BR8707578A (en) * | 1986-12-12 | 1988-12-06 | Mark Yelderman | APPARATUS AND PROCESS FOR NON-INVASIVELY MEASURING THE CONCENTRATION OF A BLOOD CONSTITUENT |
| US4907876A (en) * | 1987-05-08 | 1990-03-13 | Hamamatsu Photonics Kabushiki Kaisha | Examination apparatus for measuring oxygenation in body organs |
| US4807630A (en) * | 1987-10-09 | 1989-02-28 | Advanced Medical Systems, Inc. | Apparatus and method for use in pulse oximeters |
| US4800885A (en) * | 1987-12-02 | 1989-01-31 | The Boc Group, Inc. | Blood constituent monitoring apparatus and methods with frequency division multiplexing |
| US4972331A (en) * | 1989-02-06 | 1990-11-20 | Nim, Inc. | Phase modulated spectrophotometry |
-
1991
- 1991-03-05 US US07/665,594 patent/US5349952A/en not_active Expired - Lifetime
-
1992
- 1992-03-04 CA CA002062270A patent/CA2062270A1/en not_active Abandoned
- 1992-03-04 EP EP92301867A patent/EP0502717B1/en not_active Expired - Lifetime
- 1992-03-04 DE DE69220520T patent/DE69220520D1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0502717A1 (en) | 1992-09-09 |
| US5349952A (en) | 1994-09-27 |
| DE69220520D1 (en) | 1997-07-31 |
| EP0502717B1 (en) | 1997-06-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |