WO1997049330A1 - Oxymetre resistant aux artefacts dus aux mouvements utilisant trois longueurs d'ondes - Google Patents

Oxymetre resistant aux artefacts dus aux mouvements utilisant trois longueurs d'ondes Download PDF

Info

Publication number
WO1997049330A1
WO1997049330A1 PCT/US1997/011263 US9711263W WO9749330A1 WO 1997049330 A1 WO1997049330 A1 WO 1997049330A1 US 9711263 W US9711263 W US 9711263W WO 9749330 A1 WO9749330 A1 WO 9749330A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical signals
individual
signal
optical
signals
Prior art date
Application number
PCT/US1997/011263
Other languages
English (en)
Inventor
David M. Shemwell
Andrew J. W. Brown
Marc A. Norsen
Original Assignee
Falcon Medical, Inc.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Falcon Medical, Inc. filed Critical Falcon Medical, Inc.
Priority to AU35832/97A priority Critical patent/AU3583297A/en
Publication of WO1997049330A1 publication Critical patent/WO1997049330A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6813—Specially adapted to be attached to a specific body part
    • A61B5/6825—Hand
    • A61B5/6826—Finger
    • 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
    • A61B5/14551—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 for measuring blood gases
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/683—Means for maintaining contact with the body
    • A61B5/6838—Clamps or clips
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
    • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
    • 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

Definitions

  • the present invention relates to pulse oximetry, and more particularly, to apparatus and methods for pulse oximetry measurements.
  • pulse oximeters which use a combination of two light emitting diodes (LEDs), one red and one infrared, are used to monitor the patient functional blood oxygen saturation (SaC ⁇ ) .
  • the probe portion of the pulse oximeter is designed to be disposable.
  • the design of current art reusable probe normally consists of a clamshell type plastic housing for enclosing one of the patient's fingers.
  • the LED emitters are usually situated in the part of the housing designed to cover the fingernail, and the detector (usually a photodiode) is situated in the portion of the housing designed to cover the pad of the fingertip.
  • the electrical cable which transmits the signals back to the pulse oximeter monitor usually emanates from the part of the housing on the dorsal side of the clamshell housing.
  • the emitter and detector components are usually embedded in a sandwich of plastic layers which contain the wires and LED detectors which are laminated to a layer of tape.
  • the disposable probe is wrapped around the fingertip and the tape is wrapped to adhere to both the finger and the outside of the probe.
  • the end of the patient's finger is nearly immobilized by the tape/probe structure. The purpose of this immobilization is to reduce fmger motion and thus reduce motion artifact. This system is not comfortable for the patient and is ineffective m reducing motion artifact.
  • the invention is an apparatus for performing blood oximetry measurements in the body of an individual.
  • the apparatus including a transmit signal circuit, an optical signal circuit, a probe, and a signal processing circuit.
  • the transmit signal circuit produces an electrical transmit signal.
  • the optical signal circuit receives the electrical transmit signal and produces at least first, second and third optical signals in response thereto.
  • the at least first, second and third optical signals include optical energy at distinct optical wavelengths.
  • the probe receives the at least first, second and third optical signals and transmits the at least first, second and third optical signals through a portion of the body of the individual.
  • the probe also receives the at least first, second and third optical signals after transmission through the portion of the body of the individual and produces at least first, second and third transmission signals m response to the transmitted at least first, second and third optical signals.
  • the signal processing circuit receives the at least first, second and third transmission signals and produces an indication of blood oximetry measurements in the body of the individual in response thereto, regardless of whether the at least first, second and third optical signals are produced when the probe moves relative to the portion of the body of the individual.
  • the invention is an apparatus for performing blood oximetry measurements m the body of an individual in the presence of ambient light conditions.
  • the apparatus includes a transmit signal circuit, an optical signal circuit, a probe, and a signal processing circuit.
  • the transmit signal circuit produces an electrical transmit signal.
  • the optical signal circuit receives the electrical transmit signal and produces at least first, second and third optical signals in response thereto. Each of the at least first, second and third optical signals includes optical energy at a distinct optical wavelength.
  • the probe receives the at least first, second and third optical signals and transmits the at least first, second and third optical signals through a portion of the body of the individual.
  • the probe also receives the at least first, second and third optical signals after transmission through the portion of the body of the individual and produces at least first, second and third transmission signals in response to the transmitted at least first, second and third optical signals.
  • the signal processing circuit receives the at least first, second and third transmission signals and produces therefrom a system of eguations representative of the relationships among the at least first, second and third transmission signals as a function of the SaO , the system or equations being solvable to produce an unambiguous measurement of the SaO .
  • the invention is an apparatus for performing blood oximetry measurements m the body of an individual m the presence of ambient light conditions.
  • the apparatus includes a transmit signal circuit, an optical signal circuit, d probe, and a signal processing circuit.
  • the transmit signal circuit produces an electrical transmit signal.
  • the optical signal circuit receives the electrical transmit signal and produces at least first, second and third optical signals in response thereto. Each of the at least first, second and third optical signals include optical energy at a distinct optical wavelength.
  • the probe receives the at least first, second and third optical signals and transmits the at least first, second and third optical signals through a portion of the body of the individual.
  • the probe also receives the at least first, second and third optical signals after transmission through the portion of the body of the individual, and produces at least one transmission signal in response to the transmitted at least first, second and third optical signals.
  • the presence of variable ambient light conditions affects all of the transmitted at least first, second and third optical signals equally and, hence, can easily be removed by signal processing techniques described herein.
  • the signal processing circuit receives the at least first, second and third transmission signals and produces an indication of blood oximetry measurements in the body of the individual, regardless of whether the at least first, second and third optical signals are produced when the probe moves relative to the portion of the body of the individual.
  • Figure 1 is a graph of the absorption coefficient of blood as a function of wavelength of light.
  • Figure 2 is a graph of the alternating current (AC) signal as a runction of time.
  • Figure 3 is a block diagram or a preferred embodiment of the invention.
  • the motion artifact reduction that is accomplished through this invention is independent of the probe design and instead relies on the process of using three independent wavelengths of light specifically to remove common mode signal variation-induced motion artifact. It is not unknown to use a variety of wavelengths of light in a pulse oximeter. However, in previous cases the introduction of the additional wavelength was done m order to examine blood gases other than oxygen. However, it is believed that the use of three wavelengths to provide a motion reference is unique to this invention.
  • the three sources of the wavelengths of light are lasers, which allow the source to be located remote from the finger via a fiber optic pathway, and allow for much more precise spectral separation of the sources.
  • the present invention specifically uses three independent wavelengths, together with conventional associated mathematical analysis, to eliminate or significantly reduce artifacts in the pulse oximetry measurement caused by common mode variations m the detected intensity of the investigating wavelengths.
  • This common mode variation is the major component of motion artifacts in current art pulse oximetry.
  • the measurement of this invention may be made with virtually any three wavelengths, but superior performance and enhanced practicality encourages certain wavelength choices.
  • Figure 1 is a graph of the absorption coefficient of blood as a function of wavelength of light, and shows a typical set of three laser wavelengths superimposed over the respective absorption curves 10 and 20 for oxygenated and deoxygenated hemoglobin.
  • Three laser diode wavelengths (635 nm, 670 nm, 780 nm) are indicated m Figure 1. These three wavelengths are flashed on for short periods of time in cyclic sequence m a manner similar to that of a current production pulse oximeter.
  • wavelengths 21, 22 are in the red portion of the spectrum and the third wavelength 23 is in the infrared portion of the spectrum.
  • a typical pulse format would turn on the source of wavelength 21 from 100 to 200 microseconds, wait a similar amount of time, then turn on the source of wavelength 22 similarly, then repeat the entire sequence for wavelength 23. When recorded over time it can be seen that the absorption of each wavelength is modulated by the pressure waves of the heartbeat.
  • the three wavelengths 21, 22, and 23 shown are common, but other wavelengths could be used as will be understood by those skilled in the art (indeed virtually any set of three independent wavelengths can be used, although some wavelengths are more optimal than others) .
  • the three independent lasers or light emitting diodes, LEDs
  • a detector which may be an optical fiber or a photodiode.
  • a typical absorption curve showing the AC component of absorption schematically is shown in Figure 2.
  • Figure 2 is a graph of the alternating current (AC) signal as a function of time.
  • the detector is moved rhythmically with a repetition rate similar to a human pulse rate it is very easy to provoke an erroneous reading in a present-day production pulse oximeter. This is the case because the movement due to the pressure pulse causes a rhythmic variation in the signal intensity, such as that shown in Figure 2.
  • Typical curves showing the heartbeat caused variations and the common mode motion variations are shown schematically in Figure 2.
  • the pulse oximeter monitor can misinterpret them as heartbeat variations and produce the wrong answer.
  • Sophisticated monitors can be controlled by software that allows the monitor to infer the existence of motion and thus ignore the bad data.
  • no current monitor is immune to common mode rhythmic motions of the detector and emitter complex.
  • FIG. 3 is a block diagram of a preferred embodiment of the invention.
  • the three light signals each show a time-varying amplitude modulation which is caused when the pressure waves of the heartbeat produce an expansion of the body at the measurement site.
  • the block diagram in Figure 3 shows the process by which three wavelengths are used to eliminate common mode motion artifact.
  • the data is gathered by the standard pulse oximetry technique, and then subjected to mathematical analysis to solve for the three unknowns (oxygenated- deoxygenated blood, scattering and absorption of all other sources, and common mode signal variations), m the presence of the three measured quantities.
  • the signals representing the data are processed to represent normalized values and then the resulting signals are ratioed m order to form a single index which determines SaO in the presence of common mode signal variations which affect the measurements at all three wavelengths, such as motion artifact.
  • the techniques of using measurements due to the three different wavelengths of light will recognize the techniques of using measurements due to the three different wavelengths of light as methods of inverting the measurement system's equation matrix. There are many specific methods which will allow such a solution. Even m the case where the equations are not linear, they can be solved by, for example, developing a linear approximation or by the use of calibration tables.
  • FIG. 3 shows a functional block diagram of the current invention.
  • the overall apparatus 100 includes signal production and analysis circuitry 102, signal conduits 104 and a pulse oximetry probe 106.
  • the signal production and analysis circuitry 102 can be included in a single enclosure 108 (as shown) or may be distributed as necessary and as will be appreciated by those skilled in the electronic circuitry arts.
  • the signal conduits 104 carry signals between the signal production and analysis circuitry 102 and the pulse oximetry probe 106.
  • the signal conduits 104 can carry electrical signals (in which case they will be electrical conductors, such as stranded copper wires) or they can carry optical signals (in which case they will be optical conductors, such as optical fibers) .
  • the signal production and analysis circuitry 102 can include a transmit signal circuit 110 that produces an electrical transmit signal.
  • the electrical transmit signal is received by an optical signal circuit 112 over a line 114.
  • the optical signal circuit 112 produces optical signals at three different wavelengths in response to the electrical transmit signal. Each of the three different wavelengths is produced by a separate source 116,, 116.>, and 116 * . And then directed onto a first conduit 118 (which may be an optical fiber bundle) that carries the optical signals at the three different wavelengths to the pulse oximetry probe 106.
  • the three wavelength sources 116,, 116v, and 116 are shown as laser diodes which, in the preferred embodiment, are located in the enclosure 108. It is also possible that the three separate wavelength sources could be located at the site of the pulse oximetry probe 106, where they would respond to electrical signals carried by the first conduit 118 to the pulse oximetry probe 106. In either case, the three wavelength sources 116,, 116-, and 116, could be LEDs rather than laser diodes.
  • the signal conduits 104 can be detachable from the pulse oximetry probe 106 at a connector 120. This enables the pulse oximetry probe 106 to be discarded or reprocessed for reuse, if desired. The detachable portion of the pulse oximetry probe 106 is usually connected to the patient's finger 122.
  • the three wavelength sources 116,, 116 , and 116 are pulsed sequentially by the transmit signal circuit 110, and the three wavelengths of light from the three wavelength sources transit the tip of the finger 122, after leaving an emitter 124.
  • This light is received at a detector site 124, which may be either a fiber optic or a photodetector such as a photodiode.
  • Signals, either optical or electronic, from the detector site 124 are transmitted through a return conduit 126 to the enclosure 108 for processing by a signal processing circuit 128.
  • the signal processing circuit 128 performs the mathematical equivalent of inverting the matrix of three equations in three signals to produce a common mode error-free pulse oximetry reading. As discussed above, one such mathematical method is via production of the super-ratio of signals.
  • the signals received through the return conduit 126 are amplified by an amplifier 130 and then portions of the signals are sent to first and second ratio circuits 132 and 134.
  • the first ratio circuit 132 produces the ratio of the magnitude of the first red wavelength signal to the magnitude of the infrared wavelength signal.
  • the second ratio circuit 134 produces the ratio of the magnitude of the second red wavelength signal to the magnitude of the infrared wavelength signal. Signals representing these two ratios are then conducted to a final signal processing circuit 136 over respective signal lines 138 and 140.
  • the final signal processing circuit 136 uses the signals carrying the two ratios and dedicated electronic circuitry (including a properly programmed microprocessor and calibration tables, as desired) to produce signals that indicate the current value of SaO / or the presence of a common mode artifact on the conventional display 138.
  • the super-ratio measurement method can be used as a noise reduction technique, or as a check on the accuracy of the direct three wavelength measurement.
  • the display 138 may choose the most optimal value, via additional processing in the final signal processing circuit 136 under any given circumstance.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Health & Medical Sciences (AREA)
  • Pathology (AREA)
  • Veterinary Medicine (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Biomedical Technology (AREA)
  • Public Health (AREA)
  • Biophysics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Signal Processing (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Physiology (AREA)
  • Psychiatry (AREA)
  • Toxicology (AREA)
  • Artificial Intelligence (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Optics & Photonics (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)

Abstract

L'invention concerne un procédé et un dispositif destiné à effectuer des mesures à l'aide d'un oxymètre résistant aux artéfacts dus aux mouvements, utilisant trois longueurs d'ondes lumineuses, et les procédés d'utilisation de ce dispositif. Des circuits de production d'énergie lumineuse (112) produisent des impulsions d'au moins trois longueurs d'ondes lumineuses distinctes, telles que celles produites entre des diodes laser. Les impulsions sont transmises de façon cyclique à travers une partie du corps d'un patient, telle un doigt (122), et les signaux représentant la quantité de lumière aux trois longueurs d'ondes distinctes sont transmises aux circuits de traitement des signaux (128). Les circuits de traitement des signaux produisent des signaux indiquant le taux de saturation du sang en oxygène du patient et la présence d'artéfacts dus aux mouvements.
PCT/US1997/011263 1996-06-27 1997-06-27 Oxymetre resistant aux artefacts dus aux mouvements utilisant trois longueurs d'ondes WO1997049330A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU35832/97A AU3583297A (en) 1996-06-27 1997-06-27 Motion artifact resistant oximeter using three wavelengths

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US67015596A 1996-06-27 1996-06-27
US08/670,155 1996-06-27

Publications (1)

Publication Number Publication Date
WO1997049330A1 true WO1997049330A1 (fr) 1997-12-31

Family

ID=24689213

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/011263 WO1997049330A1 (fr) 1996-06-27 1997-06-27 Oxymetre resistant aux artefacts dus aux mouvements utilisant trois longueurs d'ondes

Country Status (2)

Country Link
AU (1) AU3583297A (fr)
WO (1) WO1997049330A1 (fr)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1013218A3 (fr) * 1998-12-25 2001-06-06 Mitsui Mining & Smelting Co., Ltd. Méthode pour des mesures du taux de sucre sangin et appareil
DE10321338A1 (de) * 2003-05-13 2004-12-02 MCC Gesellschaft für Diagnosesysteme in Medizin und Technik mbH & Co. KG Verfahren und Vorrichtung zur Bestimmung von Blutkomponenten mittels der Methode der ratiometrischen absoluten Pulsspektroskopie
US7277741B2 (en) * 2004-03-09 2007-10-02 Nellcor Puritan Bennett Incorporated Pulse oximetry motion artifact rejection using near infrared absorption by water
WO2008042147A2 (fr) * 2006-09-29 2008-04-10 Nellcor Puritan Bennett Llc Réseau de diodes électroluminescentes symétrique pour l'oximétrie pulsée
US7684842B2 (en) 2006-09-29 2010-03-23 Nellcor Puritan Bennett Llc System and method for preventing sensor misuse
US8219170B2 (en) 2006-09-20 2012-07-10 Nellcor Puritan Bennett Llc System and method for practicing spectrophotometry using light emitting nanostructure devices
US8265724B2 (en) 2007-03-09 2012-09-11 Nellcor Puritan Bennett Llc Cancellation of light shunting
US8280469B2 (en) 2007-03-09 2012-10-02 Nellcor Puritan Bennett Llc Method for detection of aberrant tissue spectra
US8315685B2 (en) 2006-09-27 2012-11-20 Nellcor Puritan Bennett Llc Flexible medical sensor enclosure
US8600469B2 (en) 2005-09-29 2013-12-03 Covidien Lp Medical sensor and technique for using the same
US8862194B2 (en) 2008-06-30 2014-10-14 Covidien Lp Method for improved oxygen saturation estimation in the presence of noise
US8930145B2 (en) 2010-07-28 2015-01-06 Covidien Lp Light focusing continuous wave photoacoustic spectroscopy and its applications to patient monitoring
US8965473B2 (en) 2005-09-29 2015-02-24 Covidien Lp Medical sensor for reducing motion artifacts and technique for using the same
US9351674B2 (en) 2005-03-03 2016-05-31 Covidien Lp Method for enhancing pulse oximetry calculations in the presence of correlated artifacts
US9833146B2 (en) 2012-04-17 2017-12-05 Covidien Lp Surgical system and method of use of the same
US9895068B2 (en) 2008-06-30 2018-02-20 Covidien Lp Pulse oximeter with wait-time indication
US9924896B2 (en) 2014-06-23 2018-03-27 Koninklijke Philips N.V. Device, system and method for determining the concentration of a substance in the blood of a subject
US10022058B2 (en) 2006-09-28 2018-07-17 Covidien Lp System and method for pulse rate calculation using a scheme for alternate weighting
US10076276B2 (en) 2008-02-19 2018-09-18 Covidien Lp Methods and systems for alerting practitioners to physiological conditions

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4714341A (en) * 1984-02-23 1987-12-22 Minolta Camera Kabushiki Kaisha Multi-wavelength oximeter having a means for disregarding a poor signal
US5645060A (en) * 1995-06-14 1997-07-08 Nellcor Puritan Bennett Incorporated Method and apparatus for removing artifact and noise from pulse oximetry

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4714341A (en) * 1984-02-23 1987-12-22 Minolta Camera Kabushiki Kaisha Multi-wavelength oximeter having a means for disregarding a poor signal
US5645060A (en) * 1995-06-14 1997-07-08 Nellcor Puritan Bennett Incorporated Method and apparatus for removing artifact and noise from pulse oximetry

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1013218A3 (fr) * 1998-12-25 2001-06-06 Mitsui Mining & Smelting Co., Ltd. Méthode pour des mesures du taux de sucre sangin et appareil
DE10321338A1 (de) * 2003-05-13 2004-12-02 MCC Gesellschaft für Diagnosesysteme in Medizin und Technik mbH & Co. KG Verfahren und Vorrichtung zur Bestimmung von Blutkomponenten mittels der Methode der ratiometrischen absoluten Pulsspektroskopie
US7277741B2 (en) * 2004-03-09 2007-10-02 Nellcor Puritan Bennett Incorporated Pulse oximetry motion artifact rejection using near infrared absorption by water
US9351674B2 (en) 2005-03-03 2016-05-31 Covidien Lp Method for enhancing pulse oximetry calculations in the presence of correlated artifacts
US8965473B2 (en) 2005-09-29 2015-02-24 Covidien Lp Medical sensor for reducing motion artifacts and technique for using the same
US8600469B2 (en) 2005-09-29 2013-12-03 Covidien Lp Medical sensor and technique for 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
US8315685B2 (en) 2006-09-27 2012-11-20 Nellcor Puritan Bennett Llc Flexible medical sensor enclosure
US10022058B2 (en) 2006-09-28 2018-07-17 Covidien Lp System and method for pulse rate calculation using a scheme for alternate weighting
US7684842B2 (en) 2006-09-29 2010-03-23 Nellcor Puritan Bennett Llc System and method for preventing sensor misuse
WO2008042147A3 (fr) * 2006-09-29 2008-05-22 Nellcor Puritan Bennett Llc Réseau de diodes électroluminescentes symétrique pour l'oximétrie pulsée
WO2008042147A2 (fr) * 2006-09-29 2008-04-10 Nellcor Puritan Bennett Llc Réseau de diodes électroluminescentes symétrique pour l'oximétrie pulsée
US8280469B2 (en) 2007-03-09 2012-10-02 Nellcor Puritan Bennett Llc Method for detection of aberrant tissue spectra
US8265724B2 (en) 2007-03-09 2012-09-11 Nellcor Puritan Bennett Llc Cancellation of light shunting
US10076276B2 (en) 2008-02-19 2018-09-18 Covidien Lp Methods and systems for alerting practitioners to physiological conditions
US11298076B2 (en) 2008-02-19 2022-04-12 Covidien Lp Methods and systems for alerting practitioners to physiological conditions
US8862194B2 (en) 2008-06-30 2014-10-14 Covidien Lp Method for improved oxygen saturation estimation in the presence of noise
US9895068B2 (en) 2008-06-30 2018-02-20 Covidien Lp Pulse oximeter with wait-time indication
US8930145B2 (en) 2010-07-28 2015-01-06 Covidien Lp Light focusing continuous wave photoacoustic spectroscopy and its applications to patient monitoring
US9833146B2 (en) 2012-04-17 2017-12-05 Covidien Lp Surgical system and method of use of the same
US9924896B2 (en) 2014-06-23 2018-03-27 Koninklijke Philips N.V. Device, system and method for determining the concentration of a substance in the blood of a subject

Also Published As

Publication number Publication date
AU3583297A (en) 1998-01-14

Similar Documents

Publication Publication Date Title
WO1997049330A1 (fr) Oxymetre resistant aux artefacts dus aux mouvements utilisant trois longueurs d'ondes
EP0871396B1 (fr) Procede et dispositif pour faciliter la compatibilite entre sphygmo-oxymetres et sondes a capteur
US6397091B2 (en) Manual and automatic probe calibration
US6647279B2 (en) Hybrid optical delivery system for photoplethysmography
JP3789487B2 (ja) パルス酸素濃度測定における偽信号の検出方法
EP0619981B1 (fr) Capteur destiné à la surveillance de la circulation artérielle
US5279295A (en) Non-invasive oximeter arrangement
US6018674A (en) Fast-turnoff photodiodes with switched-gain preamplifiers in photoplethysmographic measurement instruments
KR100376649B1 (ko) 저포화도에대해최적화된산소포화도측정기및센서
US5058588A (en) Oximeter and medical sensor therefor
US8442609B2 (en) Oral health measurement clamping probe, system and method
WO1997022293A9 (fr) Procede et dispositif pour faciliter la compatibilite entre sphygmo-oxymetres et sondes a capteur
EP0341059A2 (fr) Mesure de pouls et de teneur en oxygène
WO1999029231A1 (fr) Appareil et procede de surveillance photoplethysmographique amelioree de plusieurs especes d'hemoglobines a l'aide d'emetteurs a longueur d'onde centrale optimisee
US20130158413A1 (en) Optical measurement of physiological blood parameters
WO2012166254A1 (fr) Détermination sur la base d'une onde de densité de photon de paramètres sanguins physiologiques
US20150018649A1 (en) Methods and systems for using a differential light drive in a physiological monitor
EP0555553A2 (fr) Système amélioré de surveillance du sang artériel
EP0329196B1 (fr) Dispositif de mesure d'oxygène avec sonde
RU2040912C1 (ru) Оптический способ определения оксигенации крови и устройство для его осуществления
CN115426948A (zh) 通过正向电压测量的传感器检验
EP3434182B1 (fr) Systeme de surveillance de l'approvisionnement en sang de l'organe transplante
US8712492B2 (en) Photon density wave based determination of physiological blood parameters
EP0756848A1 (fr) Appareil de mesure non-invasive dans un corps humain ou animal
JPH04166133A (ja) 光学式血液測定装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE HU IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN ZW AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH KE LS MW SD SZ UG ZW AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: CA

NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 98503577

Format of ref document f/p: F

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase