CA1239225A - Multiple wavelength light photometer for non-invasive monitoring - Google Patents

Multiple wavelength light photometer for non-invasive monitoring

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Publication number
CA1239225A
CA1239225A CA000488142A CA488142A CA1239225A CA 1239225 A CA1239225 A CA 1239225A CA 000488142 A CA000488142 A CA 000488142A CA 488142 A CA488142 A CA 488142A CA 1239225 A CA1239225 A CA 1239225A
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CA
Canada
Prior art keywords
pulsed light
light
organ
spectrophotometer
light spectrophotometer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000488142A
Other languages
French (fr)
Inventor
Ivo Giannini
Marco Ferrari
Amilcare Carpi De Resmini
Paolo Fasella
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sclavo SpA
Consiglio Nazionale delle Richerche CNR
Istituto Superiore di Sanita ISS
Original Assignee
Sclavo SpA
Consiglio Nazionale delle Richerche CNR
Istituto Superiore di Sanita ISS
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Application granted granted Critical
Publication of CA1239225A publication Critical patent/CA1239225A/en
Expired legal-status Critical Current

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Classifications

    • 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
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
    • G01J1/16—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors
    • G01J1/18—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors using comparison with a reference electric value
    • G01J2001/182—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors using comparison with a reference electric value with SH sample and hold circuits
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/44—Electric circuits
    • G01J2001/4446—Type of detector
    • G01J2001/4453—PMT
    • 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
    • G01N2021/3129—Determining multicomponents by multiwavelength light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00—Features of devices classified in G01N21/00
    • G01N2201/06—Illumination; Optics
    • G01N2201/069—Supply of sources
    • G01N2201/0696—Pulsed
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00—Features of devices classified in G01N21/00
    • G01N2201/08—Optical fibres; light guides
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00—Features of devices classified in G01N21/00
    • G01N2201/12—Circuits of general importance; Signal processing
    • G01N2201/126—Microprocessor processing

Abstract

ABSTRACT OF THE DISCLOSURE

A multiple wavelength pulsed light spectro-photometer for non-invasive monitoring and its use in measuring blood circulatory and local metabolism parameters in living organs.

Description

2~

DESCRIPTION
Sigrlificant developments in medical diagn~stics have been brought about in recent years by the introduction of non-invasive methodlcs9 Among these, near-infrared (I.R~) spectro~oopy and instruments have been utilized to characterize biological tissues in vivo.
I~Ro spectrophotometry rests upon the relative ; transpærency of biological materials to photon~ in t~e near I.R. ~700-900 nm). In situ photon transmis~ion through organs is sufficient to permit monitoring of absorptive changes in the tissues. In this ~pectral region, only some chromophores of great . function~l significance absorb light: the heme of : 15 he~oglobin whereby changes in local hematic volume : and equilibrium between oxyhemoglobin (HbO2) and hemoglobin (Hb) can be assessed, a~d ~he visible : copper of cytochromeo~idase (cyt a,a3), i.e. the terminal enzyme in the mitochondrial respiratory chain which cataly3es 95cjo cf the cell oxygen (2) ; input.
Since the mit'ochondrial respiratory chaln is the main gateway to utilizing the free energy obtai~ed in the variou~ metabolisms 9 in vivo 25 : e~aluation of the redox state of cyt a7a3 ~ay be ~; of great assistance in assessing t~e functional sta~e of cells in various physiopathological ituatio~s ~E~Dora, J. Neurochem. 42, 101-108t 1984;
rscin~a, D.YIilson, J. Memb. Biolvgy 70 9 1-14 7 ~ 1982; ~.F.Jobsi~, Adv~ Neurol. 26,299, 1979~.

~'2~:

Fairly aCcurate me~hod~ are known of measuring the le~el of oxygenation in the hemoglobin circulati~g through the vascular ~y3tem of surface tissues (Ta~atani et alD ~ ~n. Biomed. Eng. $,1, 1980). In general, however, such prior methods fail to provide quantitative result~ with internal organs owing to the difficulty encountered in evaluating the effects of light diffu~ionO
Jobsis, of Duke University, recently proposed to u~e this type of ~pectroscopy to characterize cell metabolism in vivo (~S Patent No. 4,218,645), and in particular, to a~ess the oxygenation level of cerebral tissues by measuring the I.R. absorption of cytochrome-c-oxida~e (F.F~Jobsis, Science, 198,1264, 1977)~
The spectrophotometer propo~ed by Jobsis comprises:
(A) some light sources which emit sequentially radiation within the range of 700 to 1,300 nm; (B) a fiber optic which tran~mits the light to an org~n to be monitored; (C)an optical fiberWhiCh picks.up the emerging radia~ion from the mo N tored organ; and ~D) a system for converting the radiatio~ to a readily analyzed ~ignal.
However, the ~pectrophotometer proposed by Job~i~
~: . 25 provide~ unacceptable quantitative results b~ca~e it ~-; take~ into ~o ac50unt the effect~ of light di~fusion, which are quite ~ignificant and may ~ary over time;
..
further, a~d more specific~1ly, light diffusion makes the optical path no~-rectllinear and Beer-~a~bert law does not apply.
:

Thus, the instrument i5 unable to correc-t the observed data due to scattering effects.
Now, we have developed a spectrophotometer, formi.ng the subject matter of this patent application, which can provide a quantitative and simultaneous assessment of the absorption due to cytochrome-c-oxidase and the two forms (oxygenated and non-oxygenated) of hemoglobin which are present in tissues in vivo, while taking into account the effects of light diffusion and of any variations thereof 1~ over time.
According to the present invention, there is provided a multiple wavelength pulsed light spectrophoto-meter for non-invasive monitoring, comprising:
(a) a light source emitting a light beam lncluding radiation in the near I.R. and consisting of a lamp powered by ~C-ti.med pulses;
(b) a means of conducting said light beam to an organ to be monitored (c) a means of conducting light from the monitored organ : (d) a detector for receiving said light and detecting at least four radiations at signiEicant wavelengths corresponding to physiological parameters to be measured, from all those which have been supplied from -the source and propagated through the organ;
(e) an amplifi.er for converting signals generated by said detector to readily analyzed continuous signals and correcting for variations due to fluctuations of -the source;
and (f) an acquisition system including a microprocessor adapted to permit instantaneous computation of the values of the detected physiological parameters taking into account the light diffusion effects.
According to the present invention, there is also l ~5 - 3a -provided a spectrophotometric method for measuring circula-tory and local metabolism parameters in living organs by non-invasive monitoring, comprising steps of:
(a) emitting a light beam including radiation in the near I.R. and consisting of a lamp powered by AC-timed pulses;
(b) conducting said light beam to an organ to be monitored;
(c) conducting light from the monitored organ;
~d) receiving said light and detecting at least four radiations at significant wavelengths corresponding to physiological parameters to be measured, from all those which have been supplied from the source and propagated through the organ;
(e) converting signals generated by said detector to readily analyzed continuous signals and correcting for variations due to fluctuations of the source; and (f) computing instantaneously the values of the detected physiological parameters taking into account the ~ 20 light diffusion effects.
:
DESCRIPTION OF THE DRAWIN~S
A better understanding of the invention may be had by reference to the detailed description which follows, taken in conjunction with the accompanying drawings, in which:
- Fig. 1 is a block diagram representing the fundamental parts of the apparatus object of the present invention - 30 - Fig. 2 is a detailed circuit diagram o~ the powering of the ~lash light source;
- Fig. 3 is showing the positions of -the light detectors;
- 3~ -- FigO 4 is a detailed circuit diagram of the amplifier system and of the sampling system of the signals for the computer;
- Fig. 5 is a block diagram of the computer system used to collect the signals and oE its interface with the light detectors through an analogic/digital converter;
: - Fig. 6 and 7 are showing some typical cuxves of /

oxygen saturation of hemoglobin, oxydation of the cytochrome-c-oxydase and of blood volume measured by rneans of the invention's apparatus in the encephalic region at different respiratory activities in comparison with oxygen level measured by a skin electrode;
- Fig. 8 is a pictorial view of the optical fibers disposition for a simultaneous monitoring of different regions of a same body section.
The most important applications of this type of instrumentation may regard the monitoring of the circulatory and metabolic conditions of the encephala of immature babies, patients who have undergone ne~lrosurgery interventions, interventions of vascular surgery to the carotids, and in general patients un~.er total anesthesia or being subjected to intensive therapy; further applications may involve monitoring of the peripheral vascular system and cases of chronic or acute respiratory insufficiency.
Accordingly, a first object of this patent ap?lication concerns a multiple wavelength pulsed light spectrophotometer for non-invasive monitoring, as illustra-ted by ~igure 1 herein, which comprises the following parts:
1. a light source emitting radiation in the near I.~., consisting of a lamp powered by A.C.~timed pulses;
2. a means of conducting the light to an organ ~' : ' to be monitored;
3. a mea~ of co~ducti~g the light from the monitored organ~
4. a detector of at least four radiations ~ith significant wavelengths for the parameter~ to be measured9 from all those w~;ch have been ~upplied from the ~ource and propagated through the organ;
5. an amplifier for con~erting the radiation pulse signal to a readily a~alyzed continuous signal and correcting for variation~ due to fluctuations of the source; and
6. an acqui,qition sgstem including a micro-proces~or adapted to pe~it instanta~eous computation of the values of the detected physiological parameters taking into account the light diffusion effects~
: A particular embodiment of t~is invention will : be now deseribed by way of no~-limitative example.
~: ~
A circuit diagram is shown in Figure 2 of the circuitry for energizing a xenon flash lamp (Type EGeGFx200 or the like), Power for the' light flash is supplied by a capacitor CO charged to a voltage level V0. The capacitor is discharged through the lamp o~ recei~ing 2 5 a trigger pul~e .
.~".~ The triggering pulse is pro~ided by a control~.ed diode D ~ia a tranæformer ~ (Model FY604 ~ EGeG) driYen by a cloc~ C~ in synchro~iæation ~i~h the . mai~æ~ Each time ~hat a pulse reac~es the lamp~ the shaper F ~ill block the ~ucce~ive clock pul~e~ ~or ' ~ ~3~
~, a set time period which may be ~aried at will.
During the te~ts carried out thu~ ~ar9 thi~
time period was 125 ms and/vr 250 msO
The reference character M denotes a photodiode for mo~itoring the light from the lamp~ and P denotes the output preamplifier. The light from the lamp i~
directed to a fiber optic F0 by a glass len~ sy~tem 1,.
A viable variation of the foregoing scheme utili~es instead a high brilliance lamp which is DC powered through a conventional power supply (the lamp being a 75-200W xenon lamp of the Qsram XB0 Type); a chopper is placed in front of the fiber optic v~hich is rotated synchronously with the main~.
Of course, this choice of a light sourc~
involves a modified implementation of the electronic amplifying circuitry3 the duration of the light pulses being here longer than that of a light fla~h.

The light is conducted to the organ to be monitored by a flexible optical fiber of transparent glass and/or plastic material having a diameter in ; the 2 to 10 mm range. The light emerging from the ti~ue~ i~ picked up by another optical fiber generally of the same size. The optical fibers are ~-~. brought to rest on the tissue of the organ to be monitored BUC~ as to en~ure a good contact, ~ generally at a di~tan~e of a fe~ centimeter~ from eaoh other.
To thi~ aim, fvr monitoring an organ of an ; ::

i~dividu~l, the device di~closed in ~S Patents No~s 4,321~930 and 4~380,240 may be used to advantage~
Due to the high diffusion effect prevailing;
it is immaterial whether the two fibers are aligned or form an angle therebetween which may be o~ as much as 180~
Det Figure 3 illustrates the detector arrangeme~t.
The incoming light from the region being monitored and flo~ing through the ~tic~l fiber FO first branches out in two 9 and then illuminates the photocathodes of four photomultipliers PM1/~2,~3,~4 after goi~g through interference filters F1,~2,~3,F4 the front faces ~Yhereof also form an excellent mirror.
Lenses L1,L2,~3,~4 focus the light onto the ~- photocathode. The light path is indicated in dash lines.
The photomultipliers {R928 or R936 by Hammatsu), w~ich are particularl~ responsi~e in the region of the near ~ are supplied ~ith a ~oltage HV which may be ~aried or programmed in the 500 to 17100Y range through separate dividers.
~rom the p~otomultiplier anodes a signal is pic~ed up o~ resistors of relati~e low ~alue (C 3K Q) to maintain a good passband (> 1 ~lHz), and the 3ignal is amplified by pre~mpli~iers PA1rPA2lPA3,PA4 powered r~ by rechargeable batterie~ or bg a ~eparate power supply having a high immunity to noiset in order to _---~ a~oid eleGtromagnetic inductions from ~oltage dischargeG and comi~g o~er the mains. ~he batterie~
are recharged automatically. A different 9 simpler mou~t for the optic~ ia to be obtai~ed by using a four-le~ged fiber optic to illuminate the four photo~ul-tipliers separately. r~he interference filters employed have a mid-amplitude bandwidth rasging from 4 to 25 ~m (preferakl~ of 10 ~m) centered in between 700 and 950 nm and pre-ferably on 7~0,~00,8S0 and 900 ~m, respectively, (alternatively7 on 750~820,850 and 900 ~m, for example).
It would be poasible to increase the number of the channels up to five or six, or e~en above, to thereby e~hance the quantitative assessment of the scattering effects.

Sho~n in Figure 4 is an embodiment of the ~mpli~ier system and sampling eircuitry for acquisition to the computer.
The aignal~ from each of the channels, i.e~ t~at from the photodiode M of the light source and those from t~e preamplifiers PA1,PA2,PA3,PA4, are ampli~ied by a system of fast amplifier~ formed o~ two inverters H, the first of which also functions as a shaper to determi~e a fixed upgoing time (~ 2 ~s) by means of the integrating capacitor pro~rided o~ the feedback.
The two inverters are followed by a alower atage L and a sample-and-hold sampler SH~ The control signal to the sampli~ oircuit i9 ~uppl ied by a shaper F1 ~hich, in turn, ge~erates a trigger signal TR to _. co~trol the computer acquisition ~equence.
The individual channels are compared with the mo~itor in the differential stage D, ~o as to _ 9 _ ~limina~e signal fluctuations due to the souxoe oscillatio~s. T~e ~ignals Cl~C2,C3,C4 thu~ ob-tained and the trigger signal TR are supplied to the acquisition system.
Acq~isition S~stem Shown diagramatically in Figure 5 is a viable embodiment of the acquisition system for the instrument. A microprocessor A, 6502 from Apple II
is employed v~th a commercial ISAAC I/O syst~m I from Cyborg Co. capable of converting many analog signals sequentially and then passing them to the micro-processor.
The ISAAC sy~tem al~o allows analog signals to ~e passed to an external plotter PL -to provide plot B ' of the data obtained.
~he microprocessor is connected to two disk dri~ers D1 and D2, a printer S~, and to the display TY. The storage capacity of the microprocessor employed is of 48 kilobyte~. Al~o used is an additional 128 ~bytes high-speed storage card ~hich operate3 as a Yirtual disk. ~he same function~ m~y be performed, of course? practically by any other microprocessor : having comparable operating capabilitie~. The signal T~ ~rom the moni~or (indicated at ~ in Figure~ 2 and ; 25 4) initiate~ the acquisition ~equence. Once the data ~ are tran~ferred to the computer memorie~ it become~
,~. . .~
po ssible to di~play, either on line or ~ome time _ afterwardst the plots by calculati~g the value~ of ; th~ record~d p~y~iologic~l parameters~ such as the hematie volume, hemoglobin oxygen saturation, and ~23~

redox le~el of cytochrome-c-oxida~e9 through a~
algorithm which utilizes the insta~taneous value of the ~ignal at the four wavelengths.
The parameters o~ this calculation are obtained by an cpti~ization process of the ~alues calculated according to the theoretical model (D.V.Luebbers;
Advances in Exp. ~edicine and Biology, ~, 45-54, 1973) and the experimental data.
In addition to the signals from the channels C1-C4, se~eral other magnitudes from other instruments (~) are acquired.
It will be appreciated that various data processing programs may be utilized with the micro-proce~sor which allow some of the noise to be filtered out, spikes caused by instantaneous shift~ in the plots due to changes in the fiber optics-to-tissue contact to be detected and corrected, ~nd so forth, The in~trument just described affords the following adYantage~:
1~ pulse operation ma~es the ambient light background ~irtually negligible;
2. the monitor enables correction for any fluctuations in the source intensity;
3. the light measurement transmitted on at least four waYelengths enables computation of the hemoglobin ~,~, content of the tissue~ being ob6erved~ o~ its o~ygenation level, and of ~he oxyreduction state of ~ cytochrome-c oxida~e;
:~ 4. real time prvces~ing become~ ea~ible through a calculation proce~s which enable6 correction at :

any time instant of the ab~orption values for the ef~ect due to light diffu~ion;
5. the measurement stability is enhanced by t~e u~e of a ~eparate power supply for the preamplifiers a~d by synchronization o~ the source with the main~;
6~ the micropocessor pernLits the detection and correction of an~ instantaneous shifts in the plot~
due to variations in the contact between the fiber optics and tissue; and
7. it becomes possible to correlate the measure-me~ts taken by absoprtion in the near I.~. with those derived ~rom other instruments.
By way of exarnple Figures 6 a~d 7 are sho\, in,~;
the recorded plots ~or the aforesaid parameters as measured in the encephalon together with a measurement ; of the oxygen pressure at skin level taken with a transcutaneous electrode ~radiometer, ~odel TC~ 2).
Figure 6 shows a typical plot~obtained during change~ in the respiratory activity (hyperventilation-apnea). On the ab~cissa is the time in minutes On the ordinate, an mmHg scale relating to curve 1 is reproduced on the left.
Section A of the Figure corresponds to a condition of normal breathing, section B to a condition of hyperven~ilation, section G to a ` condition of apnea~ and section D again to a .~... .~
` condîtion of norm~l breathing.
The curve 2 is a measure of the hemoglobin sa*uration level9 ~he curYe 3 is a mea~ure o~ the cytochrome-c~oxidase o~ydation state, and the curYe `, ' ~:

2%~i 4 i~ a measure of the hematic ~olume.
The oxygen level in the arterial blood o the a~m ha~ been recorded for reference by means of a tran~cutaneous electrode ~Curve 1).
During the apnea, the hemoglobin ~aturatio~
level at arterial level drops from 95% down to abou-t 55~9 the oxireductive state of cytochrome-c-oxidase drops by about 155Jo from an estimated level of about 80p9 and the hematic volume increases to 12Cp from 10~.
It should be noted that the value of this parameter depends to sorne extent on the model asswned and the assumed values for the cerebral hematocri~, generally lower than the peripheral one (~l.E.Phelps et al., J. Appl. Physical 35, 275-280, 1983).
~i~ure 7 shows instead. a typical plot obtained duri~g in~alation of different gas mixtures ~air, pure ~-~ oxygen, hypoxic mixture~.
On the ab3cissa is the time in minute~.
On the ordinate, there is reproduced an mmHg scale relating to the curve 1~
In section A of the Figure, the condition is that of air breathing, in section B of breathing a hypoxic : ~ 25 mix~ure (2 10Cj~" N2 90Ck~ ~ ~d in section C ~he condition is that of breathing pure 2 The curve 2 i~ a measure o~ the oxidati~e ~tate of cytoohrom~-c--oxida~e ,~ the curve 3 is a measure OI
the ~emogloki~ saturàtion level~ and ~he ourve 4 i~
a measure of the hematic ~olume.

~3~

Here too, the level o 2 i~ the arterial blood o f th2 arm has been recorded for reference by mean~
of a transcutaneous electrode (Curve 1) b ~'~ile breathing the hypoxic mixture, the oxidatiYe state of cytochrome-c-oxidase does not vary appreciably, the saturatio~ level of hemoglobin decrea~e~ from 90~0 to about 650~9 and the hematic Yolume change~ from 10C~o to about 11~.
Based on the general ~cheme outlined above 9 a more complex instrumen~ation may be pro~ided to simultaneou~ly monitor different region~ of one and the ~ame organ.
The arrangement of theoptic~l fiber ~0 for such an instrument is shown in Figure 8 by way of e~ample.
Shown schematically at F~ i5 the ~ource of light, Ç
which may be embodied as in the preceding example~
ultiple leg fibera are used, and i~ each region ~he tr~n~mitted light is measured at at least four na~elengths.
The several detectors may be replaced ad~ntage-ously with a picture intensifier I (e.g. Thomso~-CSF
9403) coupled with a cluster of solid state siliGon detectors A.
The filter s~tem ~ ma~ be rep~aced with a si~gle fi1ter ~arying in the 750 to 900 nm.
he electric aig~als from the detector~ E ahould t~en be proce~ed b~ a ~y~tem of &mplifier~ ~imilar to the one diacussed hereinabove ~
more comple~ ins~rume~t like the one disclo~ed herein woula enable mapping of ~he metaboli~m and , ~

- 14 _ va~cular ~tate of cerebral cortex in keeping ~ith the most up-to date imaging methodics~
Also provided by this invent:ion is a spectrophotometric method for measuring circulatory and local meta~olism parameters in living organs by non-inYaSiVe monitoring, which utilizes the spectrophotometer described in the foregoing.

,6.. "
.

~'

Claims (21)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A multiple wavelength pulsed light spectro-photometer for non-invasive monitoring, comprising:
(a) a light source emitting a light beam in-cluding radiation in the near I.R. and consisting of a lamp powered by AC-timed pulses;
(b) a means of conducting said light beam to an organ to be monitored;
(c) a means of conducting light from the monitored organ;
(d) a detector for receiving said light and detecting at least four radiations at significant wavelengths corresponding to physiological parameters to be measured, from all those which have been supplied from the source and propagated through the organ;
(e) an amplifier for converting signals generated by said detector to readily analyzed continuous signals and correcting for variations due to fluctuations of the source;
and (f) an acquisition system including a micropro-cessor adapted to permit instantaneous computation of the value of the detected physiological parameters taking into account the light diffusion effects.
2. A pulsed light spectrophotometer as in claim 1, wherein the source as recited under (a) comprises a xenon flash lamp.
3. A pulsed light spectrophotometer as in claim 1, wherein the conducting means as recited under (b) and (c) comprises a flexible optical fiber.
4. A pulsed light spectrophotometer according to claim 3, wherein said flexible optical fiber is made of transparent glass.
5. A pulsed light spectrophotometer according to claim 3, wherein said flexible optical fiber is made of plastics.
6. A pulsed light spectrophotometer according to claim 3, wherein said flexible optical fiber is made of transparent glass and plastics.
7. A pulsed light spectrophotometer as in claim 1, wherein said conducting means as recited under (b) and (c) comprises a multiple leg flexible optical fiber.
8. A pulsed light spectrophotometer as in claim 3, wherein said flexible optical fiber has a diameter in the 2 to 10 mm range.
9. A pulsed light spectrophotometer as in claim 1, wherein the light from the organ being monitored, after going through interference filters, illuminates the photoca-thode of at least four photomultipliers.
10. A pulsed light spectrophotometer as in claim 1, wherein the light from the organ being monitored illuminates the photocathode of a picture intensifier coupled with a cluster of solid state detectors.
11. A pulsed light spectrophotometer as in claim 9, wherein said photomultipliers are responsive in the near I.R. region.
12. A pulsed light spectrophotometer as in claim 9, wherein said interference filters have a mid-height bandwidth within the range of 4 to 25 nm centered in the 700 to 950 nm range.
13. A pulsed light spectrophotometer as in claim 9, wherein said interference filters have a mid-height bandwidth within the range of 4 to 25 nm centered at 750,800,850 and 900 nm, respectively.
14. A pulsed light spectrophotometer as in claim 9, wherein said interference filters have a mid-height bandwidth within the range of 4 to 25 nm centered at 750,820,850 and 900 nm, respectively.
15. A pulsed light spectrophotometer as in claim 9, wherein a single filter variable within the range of 750 to 900 nm is used.
16. A pulsed light spectrophotometer as in claim 9, wherein the signal from the photodiode and those from the preamplifiers are amplified through a system of high-speed amplifiers.
17. A pulsed light spectrophotometer as in claim 16, wherein said high-speed amplifier system comprises two inverters the first of which also functions as a shaper.
18. A pulsed light spectrophotometer as in claim 17, wherein said two . are followed by a slower stage and a sample-and-hold sampler.
19. A pulsed light spectrophotometer as in claim 1, wherein each signal converted by said amplifier is compared to a monitor in a differential stage.
20. A spectrophotometric method for measuring circulatory and local metabolism in living organs by non-invasive monitoring, comprising steps of:
(a) emitting a light beam including radiation in the near I.R. and consisting of a lamp powered by AC-timed pulses;
(b) conducting said light beam to an organ to be monitored;
(c) conducting light from the monitored organ;
(d) receiving said light and detecting at least four radiations at significant wavelengths corresponding to physiological parameters to be measured, from all those which have been supplied from the source and propagated through the organ;
(e) converting signals generated by said detector to readily analyzed continuous signals and correcting for variations due to fluctuations of the source; and (f) computing instantaneously the values of the detected physiological parameters taking into account the light diffusion effects.
21. A spectrophotometric method according to claim 20, wherein several regions of one organ are simul-tanously monitor.
CA000488142A 1984-08-07 1985-08-06 Multiple wavelength light photometer for non-invasive monitoring Expired CA1239225A (en)

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IT8422247A IT1206462B (en) 1984-08-07 1984-08-07 MULTI-WAVE LENGTH PULSED LIGHT PHOTOMETER FOR NON-INVASIVE MONITORING.

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Families Citing this family (242)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2196424A (en) * 1986-10-24 1988-04-27 Boc Group Plc Detecting swelling beneath the skin
JPS63277038A (en) * 1987-05-08 1988-11-15 Hamamatsu Photonics Kk Diagnostic apparatus
US4805623A (en) * 1987-09-04 1989-02-21 Vander Corporation Spectrophotometric method for quantitatively determining the concentration of a dilute component in a light- or other radiation-scattering environment
DE3734588A1 (en) * 1987-10-13 1989-04-27 Schmidt Werner Dr Rer Nat Habi Recording photometer of high adaptability
IT1213864B (en) * 1987-12-23 1990-01-05 Consiglio Nazionale Ricerche METHOD OF DETECTION OF ENTEROGASTRIC REFLUX AND EQUIPMENT FOR THE IMPLEMENTATION OF THAT METHOD
US5036853A (en) * 1988-08-26 1991-08-06 Polartechnics Ltd. Physiological probe
AU614660B2 (en) * 1988-08-26 1991-09-05 Polartechnics Limited Physiological probe
EP0358809A1 (en) * 1988-09-15 1990-03-21 Hellige GmbH Spectrophotometer for monitoring a living organism
US5873821A (en) * 1992-05-18 1999-02-23 Non-Invasive Technology, Inc. Lateralization spectrophotometer
US5119815A (en) * 1988-12-21 1992-06-09 Nim, Incorporated Apparatus for determining the concentration of a tissue pigment of known absorbance, in vivo, using the decay characteristics of scintered electromagnetic radiation
US5353799A (en) 1991-01-22 1994-10-11 Non Invasive Technology, Inc. Examination of subjects using photon migration with high directionality techniques
CN1012557B (en) * 1990-03-17 1991-05-08 北京海淀龙兴医疗设备科技开发公司 Detection imaging method of soft tissue and its apparatus
US5441053A (en) * 1991-05-03 1995-08-15 University Of Kentucky Research Foundation Apparatus and method for multiple wavelength of tissue
US6549795B1 (en) 1991-05-16 2003-04-15 Non-Invasive Technology, Inc. Spectrophotometer for tissue examination
US5282466A (en) * 1991-10-03 1994-02-01 Medtronic, Inc. System for disabling oximeter in presence of ambient light
US5309912A (en) * 1991-11-08 1994-05-10 The United States Of America As Represented By The Secretary Of The Department Of Health And Human Services Multidimensional imaging using a single point detector for a phase encoded modulated optical carrier
JP3142079B2 (en) * 1992-03-19 2001-03-07 株式会社日立製作所 Optical CT device
US5954053A (en) * 1995-06-06 1999-09-21 Non-Invasive Technology, Inc. Detection of brain hematoma
US5853370A (en) * 1996-09-13 1998-12-29 Non-Invasive Technology, Inc. Optical system and method for non-invasive imaging of biological tissue
US6397099B1 (en) 1992-05-18 2002-05-28 Non-Invasive Technology, Inc. Non-invasive imaging of biological tissue
US6785568B2 (en) * 1992-05-18 2004-08-31 Non-Invasive Technology Inc. Transcranial examination of the brain
US5772597A (en) * 1992-09-14 1998-06-30 Sextant Medical Corporation Surgical tool end effector
US5746210A (en) * 1993-02-26 1998-05-05 David A. Benaron Device and method for detection, localization, and characterization of inhomogeneities in turbid media
US5762609A (en) * 1992-09-14 1998-06-09 Sextant Medical Corporation Device and method for analysis of surgical tissue interventions
US5447159A (en) * 1993-02-03 1995-09-05 Massachusetts Institute Of Technology Optical imaging for specimens having dispersive properties
JPH06245938A (en) * 1993-02-23 1994-09-06 Hitachi Ltd Optical measuring instrument
US5987346A (en) 1993-02-26 1999-11-16 Benaron; David A. Device and method for classification of tissue
US5588428A (en) * 1993-04-28 1996-12-31 The University Of Akron Method and apparatus for non-invasive volume and texture analysis
US5339810A (en) * 1993-05-03 1994-08-23 Marquette Electronics, Inc. Pulse oximetry sensor
US6058324A (en) * 1993-06-17 2000-05-02 Non-Invasive Technology, Inc. Examination and imaging of biological tissue
US5673701A (en) * 1994-10-07 1997-10-07 Non Invasive Technology, Inc. Optical techniques for examination of biological tissue
US5820558A (en) * 1994-12-02 1998-10-13 Non-Invasive Technology, Inc. Optical techniques for examination of biological tissue
US5435309A (en) * 1993-08-10 1995-07-25 Thomas; Edward V. Systematic wavelength selection for improved multivariate spectral analysis
US5782770A (en) * 1994-05-12 1998-07-21 Science Applications International Corporation Hyperspectral imaging methods and apparatus for non-invasive diagnosis of tissue for cancer
US5803909A (en) 1994-10-06 1998-09-08 Hitachi, Ltd. Optical system for measuring metabolism in a body and imaging method
US6542772B1 (en) * 1994-12-02 2003-04-01 Non-Invasive Technology, Inc. Examination and imaging of biological tissue
DE69627477T2 (en) * 1995-01-03 2004-03-18 Non-Invasive Technology, Inc. OPTICAL COUPLING DEVICE FOR IN-VIVO EXAMINATION OF BIOLOGICAL TISSUES
US6618614B1 (en) 1995-01-03 2003-09-09 Non-Invasive Technology, Inc. Optical examination device, system and method
US20050043596A1 (en) * 1996-07-12 2005-02-24 Non-Invasive Technology, Inc., A Delaware Corporation Optical examination device, system and method
US6240309B1 (en) * 1995-10-06 2001-05-29 Hitachi, Ltd. Optical measurement instrument for living body
US20060184047A1 (en) * 1995-11-17 2006-08-17 Yuichi Yamashita Optical measurement instrument for living body
US20040064052A1 (en) * 1996-01-02 2004-04-01 Britton Chance Non-invasive imaging of biological tissue
JP4090502B2 (en) * 1996-04-02 2008-05-28 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Localization of objects in turbid media using different wavelengths of radiation
US6018673A (en) 1996-10-10 2000-01-25 Nellcor Puritan Bennett Incorporated Motion compatible sensor for non-invasive optical blood analysis
US6023637A (en) * 1997-03-31 2000-02-08 Liu; Zhong Qi Method and apparatus for thermal radiation imaging
US6271920B1 (en) 1997-12-19 2001-08-07 Chromatics Color Sciences International, Inc. Methods and apparatus for color calibration and verification
DE69937602T2 (en) * 1998-02-11 2008-10-23 Non-Invasive Technology, Inc. PICTURE GENERATION AND IDENTIFICATION OF BRAIN TISSUE
DE69934482T2 (en) * 1998-02-11 2007-09-27 Non-Invasive Technology, Inc. PROOF, PICTURE AND IDENTIFICATION OF BREAST ENVELOPES
US20070167704A1 (en) * 1998-02-13 2007-07-19 Britton Chance Transabdominal examination, monitoring and imaging of tissue
JP2002502654A (en) * 1998-02-13 2002-01-29 ノン−インヴェイシヴ テクノロジイ，インク． Cross-abdominal examination, monitoring and imaging of tissue
US6009340A (en) * 1998-03-16 1999-12-28 Northrop Grumman Corporation Multimode, multispectral imaging system
US6090050A (en) * 1998-07-16 2000-07-18 Salix Medical, Inc. Thermometric apparatus and method
WO2000019889A1 (en) 1998-10-08 2000-04-13 University Of Kentucky Research Foundation Methods and apparatus for in vivo identification and characterization of vulnerable atherosclerotic plaques
USRE45607E1 (en) * 1998-10-13 2015-07-14 Covidien Lp Multi-channel non-invasive tissue oximeter
US7047054B2 (en) * 1999-03-12 2006-05-16 Cas Medical Systems, Inc. Laser diode optical transducer assembly for non-invasive spectrophotometric blood oxygenation monitoring
US6675031B1 (en) * 1999-04-14 2004-01-06 Mallinckrodt Inc. Method and circuit for indicating quality and accuracy of physiological measurements
US7840257B2 (en) * 2003-01-04 2010-11-23 Non Invasive Technology, Inc. Examination of biological tissue using non-contact optical probes
US7904139B2 (en) * 1999-08-26 2011-03-08 Non-Invasive Technology Inc. Optical examination of biological tissue using non-contact irradiation and detection
JP3962256B2 (en) * 2000-01-18 2007-08-22 ラジオメーター・メディカル・アー・ペー・エス Apparatus, sample cuvette, and optical measurement method
WO2001074251A2 (en) 2000-03-31 2001-10-11 Rita Medical Systems Inc. Tissue biopsy and treatment apparatus and method
EP2322085B1 (en) 2000-04-17 2014-03-12 Covidien LP Pulse oximeter sensor with piece-wise function
US8224412B2 (en) 2000-04-17 2012-07-17 Nellcor Puritan Bennett Llc Pulse oximeter sensor with piece-wise function
US6748254B2 (en) * 2001-10-12 2004-06-08 Nellcor Puritan Bennett Incorporated Stacked adhesive optical sensor
CA2494030C (en) 2002-07-26 2009-06-09 Cas Medical Systems, Inc. Method for spectrophotometric blood oxygenation monitoring
US7486985B2 (en) * 2002-08-05 2009-02-03 Infraredx, Inc. Near-infrared spectroscopic analysis of blood vessel walls
US7376456B2 (en) * 2002-08-05 2008-05-20 Infraredx, Inc. Near-infrared spectroscopic analysis of blood vessel walls
US7190986B1 (en) 2002-10-18 2007-03-13 Nellcor Puritan Bennett Inc. Non-adhesive oximeter sensor for sensitive skin
US6943881B2 (en) * 2003-06-04 2005-09-13 Tomophase Corporation Measurements of optical inhomogeneity and other properties in substances using propagation modes of light
US7676194B2 (en) * 2003-08-22 2010-03-09 Rappaport Theodore S Broadband repeater with security for ultrawideband technologies
US7162288B2 (en) * 2004-02-25 2007-01-09 Nellcor Purtain Bennett Incorporated Techniques for detecting heart pulses and reducing power consumption in sensors
US8498681B2 (en) * 2004-10-05 2013-07-30 Tomophase Corporation Cross-sectional mapping of spectral absorbance features
US7970458B2 (en) * 2004-10-12 2011-06-28 Tomophase Corporation Integrated disease diagnosis and treatment system
US20060173436A1 (en) * 2005-01-14 2006-08-03 Kimberly-Clark Worldwide, Inc. Disposable absorbent article having a waist opening with a scalloped edge
US8055321B2 (en) 2005-03-14 2011-11-08 Peter Bernreuter Tissue oximetry apparatus and method
US7865223B1 (en) 2005-03-14 2011-01-04 Peter Bernreuter In vivo blood spectrometry
US7657295B2 (en) * 2005-08-08 2010-02-02 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US7590439B2 (en) * 2005-08-08 2009-09-15 Nellcor Puritan Bennett Llc Bi-stable medical sensor and technique for using the same
US7657294B2 (en) * 2005-08-08 2010-02-02 Nellcor Puritan Bennett Llc Compliant diaphragm medical sensor and technique for using the same
US7355688B2 (en) * 2005-09-08 2008-04-08 Vioptix, Inc. Optical probe for optical imaging system
US7736382B2 (en) * 2005-09-09 2010-06-15 Lockheed Martin Corporation Apparatus for optical stimulation of nerves and other animal tissue
US20070060808A1 (en) * 2005-09-12 2007-03-15 Carine Hoarau Medical sensor for reducing motion artifacts and technique for using the same
US7618306B2 (en) * 2005-09-22 2009-11-17 3M Innovative Properties Company Conformable abrasive articles and methods of making and using the same
US7869850B2 (en) 2005-09-29 2011-01-11 Nellcor Puritan Bennett Llc Medical sensor for reducing motion artifacts and technique for using the same
US8092379B2 (en) * 2005-09-29 2012-01-10 Nellcor Puritan Bennett Llc Method and system for determining when to reposition a physiological sensor
US7899510B2 (en) * 2005-09-29 2011-03-01 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US7904130B2 (en) * 2005-09-29 2011-03-08 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US7881762B2 (en) * 2005-09-30 2011-02-01 Nellcor Puritan Bennett Llc Clip-style medical sensor and technique for using the same
US7555327B2 (en) * 2005-09-30 2009-06-30 Nellcor Puritan Bennett Llc Folding medical sensor and technique for using the same
US8233954B2 (en) * 2005-09-30 2012-07-31 Nellcor Puritan Bennett Llc Mucosal sensor for the assessment of tissue and blood constituents and technique for using the same
US7486979B2 (en) * 2005-09-30 2009-02-03 Nellcor Puritan Bennett Llc Optically aligned pulse oximetry sensor and technique for using the same
US8062221B2 (en) * 2005-09-30 2011-11-22 Nellcor Puritan Bennett Llc Sensor for tissue gas detection and technique for using the same
US7483731B2 (en) 2005-09-30 2009-01-27 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US7831298B1 (en) 2005-10-04 2010-11-09 Tomophase Corporation Mapping physiological functions of tissues in lungs and other organs
US20080077200A1 (en) * 2006-09-21 2008-03-27 Aculight Corporation Apparatus and method for stimulation of nerves and automated control of surgical instruments
US8956396B1 (en) 2005-10-24 2015-02-17 Lockheed Martin Corporation Eye-tracking visual prosthetic and method
US8792978B2 (en) 2010-05-28 2014-07-29 Lockheed Martin Corporation Laser-based nerve stimulators for, E.G., hearing restoration in cochlear prostheses and method
US8475506B1 (en) 2007-08-13 2013-07-02 Lockheed Martin Corporation VCSEL array stimulator apparatus and method for light stimulation of bodily tissues
US8012189B1 (en) 2007-01-11 2011-09-06 Lockheed Martin Corporation Method and vestibular implant using optical stimulation of nerves
US8709078B1 (en) 2011-08-03 2014-04-29 Lockheed Martin Corporation Ocular implant with substantially constant retinal spacing for transmission of nerve-stimulation light
US8945197B1 (en) 2005-10-24 2015-02-03 Lockheed Martin Corporation Sight-restoring visual prosthetic and method using infrared nerve-stimulation light
US8929973B1 (en) 2005-10-24 2015-01-06 Lockheed Martin Corporation Apparatus and method for characterizing optical sources used with human and animal tissues
US8744570B2 (en) 2009-01-23 2014-06-03 Lockheed Martin Corporation Optical stimulation of the brainstem and/or midbrain, including auditory areas
US8478386B2 (en) 2006-01-10 2013-07-02 Accuvein Inc. Practitioner-mounted micro vein enhancer
US9492117B2 (en) 2006-01-10 2016-11-15 Accuvein, Inc. Practitioner-mounted micro vein enhancer
US8838210B2 (en) 2006-06-29 2014-09-16 AccuView, Inc. Scanned laser vein contrast enhancer using a single laser
US8489178B2 (en) 2006-06-29 2013-07-16 Accuvein Inc. Enhanced laser vein contrast enhancer with projection of analyzed vein data
US9854977B2 (en) 2006-01-10 2018-01-02 Accuvein, Inc. Scanned laser vein contrast enhancer using a single laser, and modulation circuitry
US11278240B2 (en) 2006-01-10 2022-03-22 Accuvein, Inc. Trigger-actuated laser vein contrast enhancer
US10813588B2 (en) 2006-01-10 2020-10-27 Accuvein, Inc. Micro vein enhancer
US11253198B2 (en) 2006-01-10 2022-02-22 Accuvein, Inc. Stand-mounted scanned laser vein contrast enhancer
US7522948B2 (en) * 2006-05-02 2009-04-21 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US8073518B2 (en) 2006-05-02 2011-12-06 Nellcor Puritan Bennett Llc Clip-style medical sensor and technique for using the same
US7477924B2 (en) 2006-05-02 2009-01-13 Nellcor Puritan Bennett Llc Medical sensor and technique for using the same
US20080200780A1 (en) * 2006-05-11 2008-08-21 Schenkman Kenneth A Optical measurement of cellular energetics
US20070265513A1 (en) * 2006-05-11 2007-11-15 Schenkman Kenneth A Optical measurement of mitochondrial function in blood perfused tissue
US20070282181A1 (en) * 2006-06-01 2007-12-06 Carol Findlay Visual medical sensor indicator
US8594770B2 (en) 2006-06-29 2013-11-26 Accuvein, Inc. Multispectral detection and presentation of an object's characteristics
US8730321B2 (en) 2007-06-28 2014-05-20 Accuvein, Inc. Automatic alignment of a contrast enhancement system
US10238294B2 (en) 2006-06-29 2019-03-26 Accuvein, Inc. Scanned laser vein contrast enhancer using one laser
US8463364B2 (en) 2009-07-22 2013-06-11 Accuvein Inc. Vein scanner
US8126527B2 (en) * 2006-08-03 2012-02-28 University Of Washington Through Its Center For Commercialization Method and system for determining the contribution of hemoglobin and myoglobin to in vivo optical spectra
US8145288B2 (en) 2006-08-22 2012-03-27 Nellcor Puritan Bennett Llc Medical sensor for reducing signal artifacts and technique for using the same
US20080064940A1 (en) * 2006-09-12 2008-03-13 Raridan William B Sensor cable design for use with spectrophotometric sensors and method of using the same
US8219170B2 (en) * 2006-09-20 2012-07-10 Nellcor Puritan Bennett Llc System and method for practicing spectrophotometry using light emitting nanostructure devices
US8175671B2 (en) * 2006-09-22 2012-05-08 Nellcor Puritan Bennett Llc Medical sensor for reducing signal artifacts and technique for using the same
US8396527B2 (en) 2006-09-22 2013-03-12 Covidien Lp Medical sensor for reducing signal artifacts and technique for using the same
US8195264B2 (en) * 2006-09-22 2012-06-05 Nellcor Puritan Bennett Llc Medical sensor for reducing signal artifacts and technique for using the same
US7869849B2 (en) * 2006-09-26 2011-01-11 Nellcor Puritan Bennett Llc Opaque, electrically nonconductive region on a medical sensor
US7574245B2 (en) * 2006-09-27 2009-08-11 Nellcor Puritan Bennett Llc Flexible medical sensor enclosure
US7796403B2 (en) * 2006-09-28 2010-09-14 Nellcor Puritan Bennett Llc Means for mechanical registration and mechanical-electrical coupling of a faraday shield to a photodetector and an electrical circuit
US8996131B1 (en) 2006-09-28 2015-03-31 Lockheed Martin Corporation Apparatus and method for managing chronic pain with infrared light sources and heat
US8498699B2 (en) * 2008-10-03 2013-07-30 Lockheed Martin Company Method and nerve stimulator using simultaneous electrical and optical signals
US7890153B2 (en) * 2006-09-28 2011-02-15 Nellcor Puritan Bennett Llc System and method for mitigating interference in pulse oximetry
US7680522B2 (en) * 2006-09-29 2010-03-16 Nellcor Puritan Bennett Llc Method and apparatus for detecting misapplied sensors
US7476131B2 (en) 2006-09-29 2009-01-13 Nellcor Puritan Bennett Llc Device for reducing crosstalk
US8175667B2 (en) 2006-09-29 2012-05-08 Nellcor Puritan Bennett Llc Symmetric LED array for pulse oximetry
US7684842B2 (en) 2006-09-29 2010-03-23 Nellcor Puritan Bennett Llc System and method for preventing sensor misuse
US8068891B2 (en) 2006-09-29 2011-11-29 Nellcor Puritan Bennett Llc Symmetric LED array for pulse oximetry
US7883536B1 (en) 2007-01-19 2011-02-08 Lockheed Martin Corporation Hybrid optical-electrical probes
US8280469B2 (en) * 2007-03-09 2012-10-02 Nellcor Puritan Bennett Llc Method for detection of aberrant tissue spectra
US7894869B2 (en) 2007-03-09 2011-02-22 Nellcor Puritan Bennett Llc Multiple configuration medical sensor and technique for using the same
US8265724B2 (en) * 2007-03-09 2012-09-11 Nellcor Puritan Bennett Llc Cancellation of light shunting
US9380967B2 (en) 2007-04-11 2016-07-05 The Board Of Regents Of The University Of Texas System Systems and methods for measuring fetal cerebral oxygenation
US10226206B2 (en) 2007-04-11 2019-03-12 The Board Of Regents Of The University Of Texas System Systems and methods for measuring neonatal cerebral oxygenation
US7706646B2 (en) * 2007-04-24 2010-04-27 Tomophase Corporation Delivering light via optical waveguide and multi-view optical probe head
ES2385432T5 (en) * 2007-04-27 2022-09-06 Sentec Ag Device and method for the transcutaneous determination of blood gases
US9011508B2 (en) 2007-11-30 2015-04-21 Lockheed Martin Corporation Broad wavelength profile to homogenize the absorption profile in optical stimulation of nerves
US8352004B2 (en) 2007-12-21 2013-01-08 Covidien Lp Medical sensor and technique for using the same
US8346328B2 (en) 2007-12-21 2013-01-01 Covidien Lp Medical sensor and technique for using the same
US8366613B2 (en) * 2007-12-26 2013-02-05 Covidien Lp LED drive circuit for pulse oximetry and method for using same
US8577434B2 (en) 2007-12-27 2013-11-05 Covidien Lp Coaxial LED light sources
US20090168050A1 (en) * 2007-12-27 2009-07-02 Nellcor Puritan Bennett Llc Optical Sensor System And Method
US8452364B2 (en) 2007-12-28 2013-05-28 Covidien LLP System and method for attaching a sensor to a patient's skin
US20090171176A1 (en) * 2007-12-28 2009-07-02 Nellcor Puritan Bennett Llc Snapshot Sensor
US8442608B2 (en) * 2007-12-28 2013-05-14 Covidien Lp System and method for estimating physiological parameters by deconvolving artifacts
US8897850B2 (en) * 2007-12-31 2014-11-25 Covidien Lp Sensor with integrated living hinge and spring
US20090171171A1 (en) * 2007-12-31 2009-07-02 Nellcor Puritan Bennett Llc Oximetry sensor overmolding location features
US20090171166A1 (en) * 2007-12-31 2009-07-02 Nellcor Puritan Bennett Llc Oximeter with location awareness
US8092993B2 (en) 2007-12-31 2012-01-10 Nellcor Puritan Bennett Llc Hydrogel thin film for use as a biosensor
US8070508B2 (en) * 2007-12-31 2011-12-06 Nellcor Puritan Bennett Llc Method and apparatus for aligning and securing a cable strain relief
US8199007B2 (en) * 2007-12-31 2012-06-12 Nellcor Puritan Bennett Llc Flex circuit snap track for a biometric sensor
WO2009108950A2 (en) * 2008-02-29 2009-09-03 Tomophase Corporation Temperature profile mapping and guided thermotherapy
US20090247854A1 (en) * 2008-03-27 2009-10-01 Nellcor Puritan Bennett Llc Retractable Sensor Cable For A Pulse Oximeter
US8437822B2 (en) * 2008-03-28 2013-05-07 Covidien Lp System and method for estimating blood analyte concentration
US8112375B2 (en) * 2008-03-31 2012-02-07 Nellcor Puritan Bennett Llc Wavelength selection and outlier detection in reduced rank linear models
US7880884B2 (en) * 2008-06-30 2011-02-01 Nellcor Puritan Bennett Llc System and method for coating and shielding electronic sensor components
US8071935B2 (en) * 2008-06-30 2011-12-06 Nellcor Puritan Bennett Llc Optical detector with an overmolded faraday shield
US7887345B2 (en) * 2008-06-30 2011-02-15 Nellcor Puritan Bennett Llc Single use connector for pulse oximetry sensors
US20090326347A1 (en) * 2008-06-30 2009-12-31 Bennett Scharf Synchronous Light Detection Utilizing CMOS/CCD Sensors For Oximetry Sensing
US20100016732A1 (en) * 2008-07-17 2010-01-21 Lockheed Martin Corporation Apparatus and method for neural-signal capture to drive neuroprostheses or control bodily function
US8798700B1 (en) 2008-07-23 2014-08-05 Vioptix, Inc. Oximeter with marking feature
US20100076276A1 (en) * 2008-09-25 2010-03-25 Nellcor Puritan Bennett Llc Medical Sensor, Display, and Technique For Using The Same
US20100076319A1 (en) * 2008-09-25 2010-03-25 Nellcor Puritan Bennett Llc Pathlength-Corrected Medical Spectroscopy
US8364220B2 (en) * 2008-09-25 2013-01-29 Covidien Lp Medical sensor and technique for using the same
US8417309B2 (en) * 2008-09-30 2013-04-09 Covidien Lp Medical sensor
US8433382B2 (en) * 2008-09-30 2013-04-30 Covidien Lp Transmission mode photon density wave system and method
US8386000B2 (en) * 2008-09-30 2013-02-26 Covidien Lp System and method for photon density wave pulse oximetry and pulse hemometry
US8423112B2 (en) * 2008-09-30 2013-04-16 Covidien Lp Medical sensor and technique for using the same
US20100081912A1 (en) * 2008-09-30 2010-04-01 Nellcor Puritan Bennett Llc Ultrasound-Optical Doppler Hemometer and Technique for Using the Same
US8914088B2 (en) * 2008-09-30 2014-12-16 Covidien Lp Medical sensor and technique for using the same
WO2010040142A1 (en) 2008-10-03 2010-04-08 Lockheed Martin Corporation Nerve stimulator and method using simultaneous electrical and optical signals
US8725226B2 (en) 2008-11-14 2014-05-13 Nonin Medical, Inc. Optical sensor path selection
US8938279B1 (en) 2009-01-26 2015-01-20 VioOptix, Inc. Multidepth tissue oximeter
US8688186B1 (en) 2009-02-04 2014-04-01 Vioptix, Inc. Retractor device with oximeter sensor and force sensor
US9486196B1 (en) 2009-02-04 2016-11-08 Vioptix, Inc. Retractor systems with sensors
US9636096B1 (en) 2009-02-04 2017-05-02 Vioptix, Inc. Retractor systems with closed loop control
US8452366B2 (en) * 2009-03-16 2013-05-28 Covidien Lp Medical monitoring device with flexible circuitry
US8221319B2 (en) 2009-03-25 2012-07-17 Nellcor Puritan Bennett Llc Medical device for assessing intravascular blood volume and technique for using the same
US20100249550A1 (en) * 2009-03-25 2010-09-30 Neilcor Puritan Bennett LLC Method And Apparatus For Optical Filtering Of A Broadband Emitter In A Medical Sensor
US8467858B2 (en) * 2009-04-29 2013-06-18 Tomophase Corporation Image-guided thermotherapy based on selective tissue thermal treatment
US8509869B2 (en) * 2009-05-15 2013-08-13 Covidien Lp Method and apparatus for detecting and analyzing variations in a physiologic parameter
US8634891B2 (en) * 2009-05-20 2014-01-21 Covidien Lp Method and system for self regulation of sensor component contact pressure
US20100331640A1 (en) * 2009-06-26 2010-12-30 Nellcor Puritan Bennett Llc Use of photodetector array to improve efficiency and accuracy of an optical medical sensor
US8311601B2 (en) * 2009-06-30 2012-11-13 Nellcor Puritan Bennett Llc Reflectance and/or transmissive pulse oximeter
US9010634B2 (en) * 2009-06-30 2015-04-21 Covidien Lp System and method for linking patient data to a patient and providing sensor quality assurance
US20100331631A1 (en) * 2009-06-30 2010-12-30 Nellcor Puritan Bennett Llc Oxygen saturation ear sensor design that optimizes both attachment method and signal quality
US8505821B2 (en) * 2009-06-30 2013-08-13 Covidien Lp System and method for providing sensor quality assurance
US8391941B2 (en) * 2009-07-17 2013-03-05 Covidien Lp System and method for memory switching for multiple configuration medical sensor
US9061109B2 (en) 2009-07-22 2015-06-23 Accuvein, Inc. Vein scanner with user interface
US8417310B2 (en) * 2009-08-10 2013-04-09 Covidien Lp Digital switching in multi-site sensor
US8428675B2 (en) * 2009-08-19 2013-04-23 Covidien Lp Nanofiber adhesives used in medical devices
EP2470886A4 (en) 2009-08-26 2016-11-02 Tomophase Inc Optical tissue imaging based on optical frequency domain imaging
US8788001B2 (en) * 2009-09-21 2014-07-22 Covidien Lp Time-division multiplexing in a multi-wavelength photon density wave system
US8494604B2 (en) * 2009-09-21 2013-07-23 Covidien Lp Wavelength-division multiplexing in a multi-wavelength photon density wave system
US20110112382A1 (en) * 2009-11-12 2011-05-12 Nellcor Puritan Bennett Llc Systems and methods for combined physiological sensors
US8290558B1 (en) 2009-11-23 2012-10-16 Vioptix, Inc. Tissue oximeter intraoperative sensor
US20110237910A1 (en) * 2010-03-23 2011-09-29 Cas Medical Systems, Inc. Stabilized multi-wavelength laser system for non-invasive spectrophotometric monitoring
US8553223B2 (en) 2010-03-31 2013-10-08 Covidien Lp Biodegradable fibers for sensing
US8391943B2 (en) 2010-03-31 2013-03-05 Covidien Lp Multi-wavelength photon density wave system using an optical switch
US8649838B2 (en) 2010-09-22 2014-02-11 Covidien Lp Wavelength switching for pulse oximetry
CN103429153A (en) 2010-11-03 2013-12-04 华盛顿大学商业中心 Determination of tissue oxygenation in vivo
US8805465B2 (en) 2010-11-30 2014-08-12 Covidien Lp Multiple sensor assemblies and cables in a single sensor body
US8818473B2 (en) 2010-11-30 2014-08-26 Covidien Lp Organic light emitting diodes and photodetectors
WO2013154208A1 (en) * 2012-04-10 2013-10-17 国立大学法人岐阜大学 Method for identifying and quantifying types of animal hair
US9833146B2 (en) 2012-04-17 2017-12-05 Covidien Lp Surgical system and method of use of the same
CN104411241B (en) 2012-05-03 2017-09-08 维奥普蒂克斯公司 The probe geometry based on the tissue oxygenation of robust calibration and self-correcting
US9072426B2 (en) 2012-08-02 2015-07-07 AccuVein, Inc Device for detecting and illuminating vasculature using an FPGA
US10517483B2 (en) 2012-12-05 2019-12-31 Accuvein, Inc. System for detecting fluorescence and projecting a representative image
CN203289635U (en) 2013-05-10 2013-11-13 瑞声声学科技(深圳)有限公司 Spring plate and multifunctional sounder applying spring plate
EP3166494A4 (en) 2014-07-08 2018-03-21 The Board of Regents of The University of Texas System Systems and methods for measuring fetal cerebral oxygenation
AU2016233575A1 (en) 2015-03-14 2017-07-13 The Board Of Regents Of The University Of Texas System Systems and methods for measuring neonatal cerebral oxygenation
US10340408B1 (en) 2018-05-17 2019-07-02 Hi Llc Non-invasive wearable brain interface systems including a headgear and a plurality of self-contained photodetector units configured to removably attach to the headgear
US10420498B1 (en) 2018-06-20 2019-09-24 Hi Llc Spatial and temporal-based diffusive correlation spectroscopy systems and methods
CA3106626A1 (en) 2018-07-16 2020-01-23 Bbi Medical Innovations, Llc Perfusion and oxygenation measurement
US11213206B2 (en) 2018-07-17 2022-01-04 Hi Llc Non-invasive measurement systems with single-photon counting camera
AU2020268718A1 (en) 2019-05-06 2021-11-25 Hi Llc Photodetector architectures for time-correlated single photon counting
US10868207B1 (en) 2019-06-06 2020-12-15 Hi Llc Photodetector systems with low-power time-to-digital converter architectures to determine an arrival time of photon at a photodetector based on event detection time window
US11950879B2 (en) 2020-02-21 2024-04-09 Hi Llc Estimation of source-detector separation in an optical measurement system
US11771362B2 (en) 2020-02-21 2023-10-03 Hi Llc Integrated detector assemblies for a wearable module of an optical measurement system
WO2021167877A1 (en) 2020-02-21 2021-08-26 Hi Llc Multimodal wearable measurement systems and methods
US11515014B2 (en) 2020-02-21 2022-11-29 Hi Llc Methods and systems for initiating and conducting a customized computer-enabled brain research study
US11630310B2 (en) 2020-02-21 2023-04-18 Hi Llc Wearable devices and wearable assemblies with adjustable positioning for use in an optical measurement system
WO2021167890A1 (en) 2020-02-21 2021-08-26 Hi Llc Wearable module assemblies for an optical measurement system
WO2021188485A1 (en) 2020-03-20 2021-09-23 Hi Llc Maintaining consistent photodetector sensitivity in an optical measurement system
US11903676B2 (en) 2020-03-20 2024-02-20 Hi Llc Photodetector calibration of an optical measurement system
US11245404B2 (en) 2020-03-20 2022-02-08 Hi Llc Phase lock loop circuit based signal generation in an optical measurement system
WO2021188487A1 (en) 2020-03-20 2021-09-23 Hi Llc Temporal resolution control for temporal point spread function generation in an optical measurement system
US11187575B2 (en) * 2020-03-20 2021-11-30 Hi Llc High density optical measurement systems with minimal number of light sources
US11877825B2 (en) 2020-03-20 2024-01-23 Hi Llc Device enumeration in an optical measurement system
US11864867B2 (en) 2020-03-20 2024-01-09 Hi Llc Control circuit for a light source in an optical measurement system by applying voltage with a first polarity to start an emission of a light pulse and applying voltage with a second polarity to stop the emission of the light pulse
US11645483B2 (en) 2020-03-20 2023-05-09 Hi Llc Phase lock loop circuit based adjustment of a measurement time window in an optical measurement system
US11857348B2 (en) 2020-03-20 2024-01-02 Hi Llc Techniques for determining a timing uncertainty of a component of an optical measurement system

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US446871A (en) * 1891-02-24 Charles a
US3638640A (en) * 1967-11-01 1972-02-01 Robert F Shaw Oximeter and method for in vivo determination of oxygen saturation in blood using three or more different wavelengths
CA1037285A (en) * 1975-04-30 1978-08-29 Glenfield Warner Ear oximetry process and apparatus
JPS51134172A (en) * 1975-05-16 1976-11-20 Hitachi Ltd Multi-wavelength filter photometer
FR2364437A1 (en) * 1976-09-13 1978-04-07 Kollmorgen Tech Corp SPECTROPHOTOMETER WITH PARALLEL SIGNAL COLLECTION
US4295470A (en) * 1976-10-18 1981-10-20 Oximetrix, Inc. Optical catheters and method for making same
US4281645A (en) * 1977-06-28 1981-08-04 Duke University, Inc. Method and apparatus for monitoring metabolism in body organs
US4222389A (en) * 1977-10-18 1980-09-16 Institute Of Applied Biology Special Cancer Research Project Objective determination of the rate of oxygen utilization in peripheral tissue
DE2815074C2 (en) * 1978-04-07 1983-03-03 Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V., 3400 Göttingen Spectrophotometers for medical purposes
JPS5524004A (en) * 1978-06-22 1980-02-20 Minolta Camera Kk Oxymeter
GB2043880A (en) * 1979-03-05 1980-10-08 Pye Electronic Prod Ltd Noise reduction in dual beam ratio recording spectrophotometers
JPS55118738A (en) * 1979-03-07 1980-09-11 Sumitomo Electric Industries Measuring device for breathing function of internal organ and tissue of living body
DE2934190A1 (en) * 1979-08-23 1981-03-19 Müller, Gerhard, Prof. Dr.-Ing., 7080 Aalen METHOD AND DEVICE FOR MOLECULAR SPECTROSCOPY, ESPECIALLY FOR DETERMINING METABOLISM PRODUCTS
JPS56104646A (en) * 1980-01-25 1981-08-20 Minolta Camera Kk Optical analyzer for forming ratio of element contained in organism
FR2521727A2 (en) * 1981-03-25 1983-08-19 Cilas DEVICE FOR MEASURING THE STATE OF OXYDO-REDUCTION OF A LIVING ORGAN IN SITU
US4407290A (en) * 1981-04-01 1983-10-04 Biox Technology, Inc. Blood constituent measuring device and method
AU1687983A (en) * 1982-07-19 1984-01-26 Spectrascan Inc. Diaphanoscopy method and apparatus

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US5088493A (en) 1992-02-18
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