US3628525A - Blood oxygenation and pulse rate monitoring apparatus - Google Patents

Blood oxygenation and pulse rate monitoring apparatus Download PDF

Info

Publication number
US3628525A
US3628525A US834735A US3628525DA US3628525A US 3628525 A US3628525 A US 3628525A US 834735 A US834735 A US 834735A US 3628525D A US3628525D A US 3628525DA US 3628525 A US3628525 A US 3628525A
Authority
US
United States
Prior art keywords
light
tissue
oximeter device
bundle
adjacent
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 - Lifetime
Application number
US834735A
Inventor
Michael L Polanyi
David S Ostrowski
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.)
Warner Lambert Technologies Inc
Original Assignee
American Optical Corp
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 American Optical Corp filed Critical American Optical Corp
Application granted granted Critical
Publication of US3628525A publication Critical patent/US3628525A/en
Assigned to WARNER LAMBERT TECHNOLOGIES, INC., A CORP OF TX. reassignment WARNER LAMBERT TECHNOLOGIES, INC., A CORP OF TX. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WARNER LAMBERT COMPANY
Assigned to WARNER LAMBERT COMPANY, A CORP. OF DEL. reassignment WARNER LAMBERT COMPANY, A CORP. OF DEL. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: AMERICAN OPTICAL CORPORATION,
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • A61B5/14552—Details of sensors specially adapted therefor
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/02416—Detecting, measuring or recording pulse rate or heart rate using photoplethysmograph signals, e.g. generated by infrared radiation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/02416—Detecting, measuring or recording pulse rate or heart rate using photoplethysmograph signals, e.g. generated by infrared radiation
    • A61B5/02427—Details of sensor
    • 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
    • A61B5/1491—Heated applicators
    • 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
    • A61B5/6814—Head
    • A61B5/6815—Ear
    • A61B5/6816—Ear lobe

Definitions

  • the determination of oxygen saturation of the circulating blood without extracting a sample of the blood can be accomplished by transilluminating the pinna of the ear, or another suitable portion of the body, and measuring the light transmitted at a wavelength of about 650 p. against a reference wavelength of about 805 mg.
  • the ear oximeter in general, is a well-known instrument and, is described in U.S. Pat. No. 2,706,927.
  • a small incandescent lamp has been used both for illumination and for heating of the skin.
  • heat from a lamp is quickly dissipated and the skin may not become sufficiently heated for arterialization.
  • circulation is poor and little or no dissipation of heat occurs, serious discomfort or harm to the patient may result from excessive heating by the lamp.
  • cold light as used herein is intended to include any light which is rendered substantially unaccompanied by appreciable amounts of heat such as light emitted from fiber optic conductors, or light-emitting diodes which, when directed upon tissue under observation will produce minimal heating of the tissue.
  • the present invention features a system having a fixed path length of light into which portions of the body (e.g. the ear) may be positioned for transillumination whereby measurements of blood oxygen saturation obtained by such means are substantially independent of thickness of the body under test. Furthermore, greater precision in the measurement of blood oxygen saturation is accomplished by directing light into the transilluminated portion of the body specimen from points equally radially spaced a few millimeters from the axis along which light from the specimen is received for analysis. Also, an arrangement for receiving light from the transilluminated specimen at points equally radially spaced from the axis of a bundle of light rays directed into the specimen will produce similar results.
  • FIG. 1 is a diagrammatic illustration of a system and apparatus for performing oximetry and pulse rate monitoring ac cording to principles of this invention.
  • FIG. 2 is an enlarged crosssectional view of the apparatus shown in FIG. 1 wherein portions thereof pertinent to the present inventive concept are shown :in greater detail and modifications thereof are shown with dot-dash outline; and
  • FIG. 3 is a view taken along line 33 of FIG. 2 looking in the direction of the arrows.
  • FIG. I of the drawing there is illustrated an oxygen saturation and pulse rate monitoring system 10 incorporating an ear oximeter I2 functioning as a transducer in the system. Amounts of oxygen in blood flowing through an ear 14 and/or changing amounts of blood present in the ear are converted by oximeter 12 into corresponding variations in intensity of particular wavelengths of light caused to pass through the pinna of the ear.
  • System 10 further includes a remote light source 16, at least one elongated fiber optical light pipe 18 for receiving and conducting light from source 16 to car 14 and a number of bandpass filters 20 adapted to be selectively interposed between light source 16 and end 22 of light pipe 18 for filtering all but selected wavelengths of light caused to enter light pipe 18.
  • Filters 20 are conventionally so preselected as to have one transmissive to substantially only light of a wavelength of 650 mu, another transmissive to substantially only light of a wavelength of 805 p. and a third transmissive to substantially only light of a wavelength of 910 mg; the latter wavelength being used for dye dilution testing wherein 910 mp light is readily absorbed by dyes commonly used in dye dilution testing.
  • a measurement of the amount of such light transmitted through the ear is made by directing the light into a measuring and indication photoelectric system represented by block 24 in FIG. I.
  • Fiber optic light pipe 26, FIGS. 1 and 2 receives light transmitted through ear I4 and conducts the: same to the measuring and indicating means 24.
  • the measuring and indicating means 24 is calibrated to measure oxygen saturation independently to tissue pigmentation by rendering "the portion of ear 14 under observation temporarily bloodless.
  • An inflatable diaphragm 18, FIGS. 1 and 2 is provided for this purpose.
  • Compressed air directed through conduit 30 inflates diaphragm 28 whereby the adjacent portion of ear I4 is squeezed against a fixed platen 32 stopping the circulation of blood in the area between diaphragm 28 and platen 32.
  • Those interested in further details of blood monitoring systems such as that thus far described may refer to U.S. Pat. Nos. 3,068,739; 2,706,927 and 3,412,729.
  • Diaphragm 28 is transparent to light emitted from light pipe 18 and, accordingly, would be similarly transmissive to light emitted by diodes 19a. It is also pointed out that photoelectric detectors having the same general appearance as diodes 190 may be positioned adjacent to platen 32 (e.g. in the vicinity of the light-receiving end 27 of light pipe 26) in which case light pipe 26 would be replaced by electrical connections extending from such photoelectric detectors to the measuring and indicating means 24.
  • either the light-emitting end 19 or the lightreceiving end 27 of light pipes 18 and 26 respectively are formed with corresponding ends of fibers of the particular bundle thereof arranged annularly about the axis A-A(FlG. 1) of the light path through ear 14 as illustrated in H0. 3.
  • This arrangement of fibers has been found to produce greater precision in the measurement of blood oxygen saturation.
  • either one or the other of the light-emitting and light-receiving ends 19 and 27 respectively may have corresponding ends of their fibers similarly spaced from each other in two or more groups respectively disposed at approximately equal distances from each other (e.g. 4 millimeters) from the axis A-A of the light path through ear 14.
  • ear 14 With the light transmitted through ear 14 being of a temperature substantially below that of incandescence, ear 14 is heated to arterialize the portion thereof under observation by heating coil 34 (FIG. 2) which heats platen 32, keeping car 14 to within a narrow range of optimum temperature for arterialization of about 41 C.
  • heating coil 34 FIG. 2
  • Heating coil 34 is operated by proportional temperature controller 36 (FIG. 1) which includes thermistor 38 located in platen 32 adjacent the surface thereof contacted by the portion of ear 14 under observation. Electrical leads 40 connect heating coil 34 and thermistor 38 to controller 36 which, in turn, is connected to a suitable source of current SC.
  • proportional temperature controller 36 FIG. 1
  • thermistor 38 located in platen 32 adjacent the surface thereof contacted by the portion of ear 14 under observation.
  • Electrical leads 40 connect heating coil 34 and thermistor 38 to controller 36 which, in turn, is connected to a suitable source of current SC.
  • Jaw 42 is slidable toward and away from jaw 44 along a supporting hollow post 46 to which jaw 44 is fixed by clamp nut 48. Jaw 42, accordingly, may be moved away from jaw 44 sufficiently to permit insertion of ear 44 between platen 32 and diaphragm 28. Release of jaw 42 will automatically nonsubjectively clamp ear 14 in oximeter 12 with an optimum holding force normally permitting free circulation of blood through the ear.
  • Spring 50 provides the nonsubjective holding force.
  • Clam nut 52 when tightened, prevents accidental displacement of oximeter 12during use and prevents displacement of jaw 42 when diaphragm 28 is inflated to render the portion of ear 14 under observation bloodless.
  • Jaw 42 in its movement toward and away from jaw 44, is guided by pin 54 fixed in support 56 which, in turn, is fixed to post 46. Pin 54 thus maintains platen 32 and diaphragm 28 in aligned relationship with each other at all times.
  • Light pipe 26 having its end 27 fixed in support 56 at a given distance from the light-emitting end or ends 19 of one or more light-emitting light pipes 18, established the above-mentioned fixed optical path length of light into which portions of body tissue of varying thickness may be placed by adjustment of jaw 42 relative to jaw 44 independently of support 56.
  • system 10 measures variations in amounts of transmitted light resulting from changing amounts of blood perfusing ear 14 due to pulsatile characteristics of the blood flow.
  • the controlled heating of ear 14 to the optimum temperature of about 41 C. increases the normal pulsatile flow by a factor of approximately three with a corresponding increase in intensity of light transmitted through the car.
  • the monitoring of pulsatile characteristics in the ear with the aforesaid increase in light intensities provides an accurate indication of actual pulse rate, even in cases of poor peripheral circulation.
  • An oximeter device comprising:
  • a main supporting member a pair of parallel clamping jaws extending laterally from said member, said jaws being movable at least one toward the other along said member for clamping a section of body tissue between their corresponding terminal ends; light-emitting means in a first of said jaws of said pair adjacent its terminal end and a light-receiving platen adjacent the terminal of the second of said jaws between which said section of body tissue is adapted to be received for said clamping thereof and is adapted to be transilluminated by light emitted from said emitting means;
  • thermocontrol means in electrical circuit with said heating element and thermistor, said control means being responsive to variations in electrical resistance of said thermistor for maintaining the temperature of said platen and said section of tissue substantially constant during said transillumination of the tissue;
  • light intensity measuring means operatively associated with said light-receiving means for measuring the intensity of light received thereby.
  • An oximeter device according to claim 1 wherein said light-emitting means comprises one end of an elongated bundle of light-conducting fibers having a source of light adjacent its opposite end.
  • An oximeter device according to claim 1 wherein said light-emitting means comprises at least one light-emitting diode.
  • An oximeter device according to claim 1 wherein said thermistor in said platen is positioned adjacent the surface thereof against which said tissue is adapted to be clamped.
  • An oximeter device according to claim 1 wherein said movable jaw is biased toward the other jaw of said pair thereof by spring means whereby said tissue may be clamped nonsubjectively.
  • An oximeter device including means for releasably fixing said jaws against separation from a clamped relationship with said section of body tissue.
  • An oximeter device further including an inflatable transparent membrane extending over said light-emitting means and means through which an inflating medium may be directed into said membrane to distend same.
  • said light-receiving means comprises one end of an elongated bundle of light-conducting fibers and said light-intensity measuring means includes a photoelectric transducer system.
  • An oximeter device comprises at least one photoelectric detector for converting light received thereby into electrical energy and said light-intensity measuring means includes electrical energy measuring and intensity indicating means electrically connected to said detector.
  • An oximeter device wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
  • An oximeter device according to claim 10 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.
  • An oximeter device wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
  • An oximeter device according to claim 13 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.

Abstract

An ear oximeter functioning as a transducer for monitoring blood oxygen saturation and pulse rate comprising an ear clamp having a pair of opposed jaws between which body tissue may be clamped for transillumination by light emitted from one jaw into the clamped tissue. Thermostatically controlled heating means arterializes the transilluminated tissue and light emitter from the tissue is monitored by a photoelectric light-intensity meter for indication of percent oxygen in blood within the arterialized tissue.

Description

O United States Patent 1111 3,623,525
[72] Inventors Michael L. Polanyi [56] References Cited Webster; UNITED STATES PATENTS 21 A l N 251's;- 2,706,927 4/1955 WOOd 356/41 22 J 19 1969 2,790,438 4/1957 Taplin et al 128/2 L gf f? *1971 3,068,739 12 1962 Hicks,.lr.etal. 128/2 L n [73] Assignee American OpticalCorl rltion g souhbridge Mass. o anyi Primary ExaminerWilliam E. Kamm Attorneys-William C. Nealon, Noble S. Williams and Robert [54] BLOOD OXYGENATION AND PULSE RATE J Bird MONITORING APPARATUS 13 Claims, 3 Drawing Figs. U 8 Cl 128/2 R ABSTRACT: An ear oximeter functioning as a transducer for P 356/4, monitoring blood Oxygan saturation and pulse rate comprising Int Cl A6lb5/00 an ear clamp having a pair of opposed jaws between which Fieid 128/2R 2 body tissue may be clamped for transillumination by light R 2 05 emitted from one jaw into the clamped tissue. Thermostati- 5 5 cally controlled heating means arterializes the transilluminated tissue and light emitter from the tissue is monitored by a photoelectric light-intensity meter for indication of percent oxygen in blood within the arteriallized tissue.
PHOTOELECTRIC LIGHT INTENSITY METER PROPORTIONAL TEMPERATUR E CONTROLLER IN VENTOR.
Y W N MR Mm ow b A LS. Rm AV A m0 MY BLOOD OXYGENATION AND PULSE RATE MONITORING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention Tissue oximeters with particular reference to improvements in means for arterializing relevant portions of body tissue under observation.
2. Description Of The Prior Art The determination of oxygen saturation of the circulating blood without extracting a sample of the blood can be accomplished by transilluminating the pinna of the ear, or another suitable portion of the body, and measuring the light transmitted at a wavelength of about 650 p. against a reference wavelength of about 805 mg. The ear oximeter, in general, is a well-known instrument and, is described in U.S. Pat. No. 2,706,927.
In this manner of measuring oxygen saturation, it is common to heat the skin in the area under observation so as to dilate arterioles with the intent of increasing the blood flow to the point where very little deoxygenation occurs in the capillaries so that the measurement becomes essentially that of arterial oxygen saturation which in most instances is of greater clinical value than a measurement of oxygen saturation in venus blood.
Heretofore, a small incandescent lamp has been used both for illumination and for heating of the skin. However, when the blood circulation is abundant, heat from a lamp is quickly dissipated and the skin may not become sufficiently heated for arterialization. On the other hand, when circulation is poor and little or no dissipation of heat occurs, serious discomfort or harm to the patient may result from excessive heating by the lamp.
It has also been determined that in cases where the optical path length of light in an ear oximeter is varied according to the thickness of ear tissue being transilluminated, difficulty in obtaining absolute measurements of blood oxygen saturation is encountered.
The aforesaid drawbacks in prior art ear oximetry and others which may become apparent hereinafter are overcome by the present invention which is directed more particularly to a system wherein a fixed optical path length of light is used to transilluminate portions of bodies under test and heating is kept within a narrow range of a temperature which is comfortable and harmless to the patient, yet optimum in effecting arterialization.
SUMMARY OF THE INVENTION The optimum in arterialization without discomfort or harm to the patient and the corollary of greater accuracy and dependability of oxygen saturation measurements performed according to principles of this invention are accomplished by directing cold light to the portion of tissue under observation and heating that portion with a heating pad kept within a narrow range of temperature (e.g. 41 C.) which is optimum for arterialization of the skin.
The term cold light" as used herein is intended to include any light which is rendered substantially unaccompanied by appreciable amounts of heat such as light emitted from fiber optic conductors, or light-emitting diodes which, when directed upon tissue under observation will produce minimal heating of the tissue.
The present invention features a system having a fixed path length of light into which portions of the body (e.g. the ear) may be positioned for transillumination whereby measurements of blood oxygen saturation obtained by such means are substantially independent of thickness of the body under test. Furthermore, greater precision in the measurement of blood oxygen saturation is accomplished by directing light into the transilluminated portion of the body specimen from points equally radially spaced a few millimeters from the axis along which light from the specimen is received for analysis. Also, an arrangement for receiving light from the transilluminated specimen at points equally radially spaced from the axis of a bundle of light rays directed into the specimen will produce similar results.
Details of this invention will become more fully understood by reference to the following description and the accompanying drawing.
DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic illustration of a system and apparatus for performing oximetry and pulse rate monitoring ac cording to principles of this invention; and
FIG. 2 is an enlarged crosssectional view of the apparatus shown in FIG. 1 wherein portions thereof pertinent to the present inventive concept are shown :in greater detail and modifications thereof are shown with dot-dash outline; and
FIG. 3 is a view taken along line 33 of FIG. 2 looking in the direction of the arrows.
DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. I of the drawing there is illustrated an oxygen saturation and pulse rate monitoring system 10 incorporating an ear oximeter I2 functioning as a transducer in the system. Amounts of oxygen in blood flowing through an ear 14 and/or changing amounts of blood present in the ear are converted by oximeter 12 into corresponding variations in intensity of particular wavelengths of light caused to pass through the pinna of the ear.
System 10 further includes a remote light source 16, at least one elongated fiber optical light pipe 18 for receiving and conducting light from source 16 to car 14 and a number of bandpass filters 20 adapted to be selectively interposed between light source 16 and end 22 of light pipe 18 for filtering all but selected wavelengths of light caused to enter light pipe 18. Filters 20 are conventionally so preselected as to have one transmissive to substantially only light of a wavelength of 650 mu, another transmissive to substantially only light of a wavelength of 805 p. and a third transmissive to substantially only light of a wavelength of 910 mg; the latter wavelength being used for dye dilution testing wherein 910 mp light is readily absorbed by dyes commonly used in dye dilution testing.
With light of a preselected wavelength (e.g. 650 my.) directed into ear 14, a measurement of the amount of such light transmitted through the ear, which is a function of oxygen saturation, is made by directing the light into a measuring and indication photoelectric system represented by block 24 in FIG. I.
Fiber optic light pipe 26, FIGS. 1 and 2, receives light transmitted through ear I4 and conducts the: same to the measuring and indicating means 24. The measuring and indicating means 24 is calibrated to measure oxygen saturation independently to tissue pigmentation by rendering "the portion of ear 14 under observation temporarily bloodless. An inflatable diaphragm 18, FIGS. 1 and 2, is provided for this purpose. Compressed air directed through conduit 30 inflates diaphragm 28 whereby the adjacent portion of ear I4 is squeezed against a fixed platen 32 stopping the circulation of blood in the area between diaphragm 28 and platen 32. Those interested in further details of blood monitoring systems such as that thus far described may refer to U.S. Pat. Nos. 3,068,739; 2,706,927 and 3,412,729.
In connection with the matter of supplying cold light to body tissue (e.g. ear 14) under observation, it should be understood that the arrangement of lamp 16, filters 20 and light pipe 18 may be replaced by light-emitting diodes having peak emission wavelengths corresponding to the wavelengths of light transmitted by band-pass filters 20. Such diodes, also referred to as visible diodes" are well known to the artisan and readily commercially available. In this instance, lightemitting diodes 19a, shown in dot-dash outline (FIG. 2) would be located behind diaphragm 28 at a position corresponding to or near the location of the emitting end 19 of the full line of illustration of light pipe 18. In this latter case, light pipe 18 would be omitted. Diaphragm 28 is transparent to light emitted from light pipe 18 and, accordingly, would be similarly transmissive to light emitted by diodes 19a. It is also pointed out that photoelectric detectors having the same general appearance as diodes 190 may be positioned adjacent to platen 32 (e.g. in the vicinity of the light-receiving end 27 of light pipe 26) in which case light pipe 26 would be replaced by electrical connections extending from such photoelectric detectors to the measuring and indicating means 24.
Preferably, either the light-emitting end 19 or the lightreceiving end 27 of light pipes 18 and 26 respectively are formed with corresponding ends of fibers of the particular bundle thereof arranged annularly about the axis A-A(FlG. 1) of the light path through ear 14 as illustrated in H0. 3. This arrangement of fibers has been found to produce greater precision in the measurement of blood oxygen saturation. Alternatively, either one or the other of the light-emitting and light- receiving ends 19 and 27 respectively may have corresponding ends of their fibers similarly spaced from each other in two or more groups respectively disposed at approximately equal distances from each other (e.g. 4 millimeters) from the axis A-A of the light path through ear 14.
With the light transmitted through ear 14 being of a temperature substantially below that of incandescence, ear 14 is heated to arterialize the portion thereof under observation by heating coil 34 (FIG. 2) which heats platen 32, keeping car 14 to within a narrow range of optimum temperature for arterialization of about 41 C.
Heating coil 34 is operated by proportional temperature controller 36 (FIG. 1) which includes thermistor 38 located in platen 32 adjacent the surface thereof contacted by the portion of ear 14 under observation. Electrical leads 40 connect heating coil 34 and thermistor 38 to controller 36 which, in turn, is connected to a suitable source of current SC.
Platen 32 and diaphragm 28 are supported by jaws 42 and 44 respectively of oximeter 12. Jaw 42 is slidable toward and away from jaw 44 along a supporting hollow post 46 to which jaw 44 is fixed by clamp nut 48. Jaw 42, accordingly, may be moved away from jaw 44 sufficiently to permit insertion of ear 44 between platen 32 and diaphragm 28. Release of jaw 42 will automatically nonsubjectively clamp ear 14 in oximeter 12 with an optimum holding force normally permitting free circulation of blood through the ear. Spring 50 provides the nonsubjective holding force. Clam nut 52, when tightened, prevents accidental displacement of oximeter 12during use and prevents displacement of jaw 42 when diaphragm 28 is inflated to render the portion of ear 14 under observation bloodless.
Jaw 42, in its movement toward and away from jaw 44, is guided by pin 54 fixed in support 56 which, in turn, is fixed to post 46. Pin 54 thus maintains platen 32 and diaphragm 28 in aligned relationship with each other at all times. Light pipe 26 having its end 27 fixed in support 56 at a given distance from the light-emitting end or ends 19 of one or more light-emitting light pipes 18, established the above-mentioned fixed optical path length of light into which portions of body tissue of varying thickness may be placed by adjustment of jaw 42 relative to jaw 44 independently of support 56.
in its application as a pulse monitor, system 10 measures variations in amounts of transmitted light resulting from changing amounts of blood perfusing ear 14 due to pulsatile characteristics of the blood flow. The controlled heating of ear 14 to the optimum temperature of about 41 C. increases the normal pulsatile flow by a factor of approximately three with a corresponding increase in intensity of light transmitted through the car.
With the ear being held continuously within a narrow range of optimum temperature the monitoring of pulsatile characteristics in the ear with the aforesaid increase in light intensities provides an accurate indication of actual pulse rate, even in cases of poor peripheral circulation.
We claim:
1. An oximeter device comprising:
a main supporting member; a pair of parallel clamping jaws extending laterally from said member, said jaws being movable at least one toward the other along said member for clamping a section of body tissue between their corresponding terminal ends; light-emitting means in a first of said jaws of said pair adjacent its terminal end and a light-receiving platen adjacent the terminal of the second of said jaws between which said section of body tissue is adapted to be received for said clamping thereof and is adapted to be transilluminated by light emitted from said emitting means;
an electrical heating element adjacent said platen for heat:
ing same;
a thermistor in said platen;
temperature control means in electrical circuit with said heating element and thermistor, said control means being responsive to variations in electrical resistance of said thermistor for maintaining the temperature of said platen and said section of tissue substantially constant during said transillumination of the tissue;
means adjacent said terminal end of said jaw for receiving light transmitted through said tissue and;
light intensity measuring means operatively associated with said light-receiving means for measuring the intensity of light received thereby.
2. An oximeter device according to claim 1 wherein said light-emitting means comprises one end of an elongated bundle of light-conducting fibers having a source of light adjacent its opposite end.
3. An oximeter device according to claim 1 wherein said light-emitting means comprises at least one light-emitting diode.
4. An oximeter device according to claim 1 wherein said thermistor in said platen is positioned adjacent the surface thereof against which said tissue is adapted to be clamped.
5. An oximeter device according to claim 1 wherein said movable jaw is biased toward the other jaw of said pair thereof by spring means whereby said tissue may be clamped nonsubjectively.
6. An oximeter device according to claim 5 including means for releasably fixing said jaws against separation from a clamped relationship with said section of body tissue.
7. An oximeter device according to claim 6 further including an inflatable transparent membrane extending over said light-emitting means and means through which an inflating medium may be directed into said membrane to distend same.
8. An oximeter device according to claim 1 wherein said light-receiving means comprises one end of an elongated bundle of light-conducting fibers and said light-intensity measuring means includes a photoelectric transducer system.
9. An oximeter device according to claim 1 wherein said light-receiving means comprises at least one photoelectric detector for converting light received thereby into electrical energy and said light-intensity measuring means includes electrical energy measuring and intensity indicating means electrically connected to said detector.
10. An oximeter device according to claim 2 wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
11. An oximeter device according to claim 10 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.
12. An oximeter device according to claim 8 wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
13. An oximeter device according to claim 13 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.
i 4 i i i

Claims (13)

1. An oximeter device comprising: a main supporting member; a pair of parallel clamping jaws extending laterally from said member, said jaws being movable at least one toward the other along said member for clamping a section of body tissue between their corresponding terminal ends; light-emitting means in a first of said jaws of said pair adjacent its terminal end and a light-receiving platen adjacent the terminal of the second of said jaws between which said section of body tissue is adapted to be received for said clamping thereof and is adapted to be transilluminated by light emitted from said emitting means; an electrical heating element adjacent said platen for heating same; a thermistor in said platen; temperature control means in electrical circuit with said heating element and thermistor, said control means being responsive to variations in electrical resistance of said thermistor for maintaining the temperature of said platen and said section of tissue substantially constant during said transillumination of the tissue; means adjacent said terminal end of said jaw for receiving light transmitted through said tissue and; light intensity measuring means operatively associated with said light-receiving means for measuring the intensity of light received thereby.
2. An oximeter device according to claim 1 wherein said light-emitting means comprises one end of an elongated bundle of light-conducting fibers having a source of light adjacent its opposite end.
3. An oximeter device according to claim 1 wherein said light-emitting means comprises at least one light-emitting diode.
4. An oximeter device according to claim 1 wherein said thermistor in said platen is positioned adjacent the surface thereof against which said tissue is adapted to be clamped.
5. An oximeter device according to claim 1 wherein said movable jaw is biased toward the other jaw of said pair thereof by spring means whereby said tissue may be clamped nonsubjectively.
6. An oximeter device according to claim 5 including means for releasably fixing said jaws against separation from a clamped relationship with said section of body tissue.
7. An oximeter device according to claim 6 further including an inflatable transparent membrane extending over said light-emitting means and means through which an inflating medium may be directed into said membrane to distend same.
8. An oximeter device according to claim 1 wherein said light-receiving means comprises one end of an elongated bundle of light-conducting fibers and said light-intensity measuring means includes a photoelectric transducer system.
9. An oximeter device according to claim 1 wherein said light-receiving means comprises at least one photoelectric detectoR for converting light received thereby into electrical energy and said light-intensity measuring means includes electrical energy measuring and intensity indicating means electrically connected to said detector.
10. An oximeter device according to claim 2 wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
11. An oximeter device according to claim 10 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.
12. An oximeter device according to claim 8 wherein portions of said light-conducting fibers adjacent said one end of said bundle are spaced a preselected radial distance away from the principal axis of the bundle.
13. An oximeter device according to claim 13 wherein said portions of said light-conducting fibers are disposed annularly about said principal axis of said bundle.
US834735A 1969-06-19 1969-06-19 Blood oxygenation and pulse rate monitoring apparatus Expired - Lifetime US3628525A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US83473569A 1969-06-19 1969-06-19

Publications (1)

Publication Number Publication Date
US3628525A true US3628525A (en) 1971-12-21

Family

ID=25267661

Family Applications (1)

Application Number Title Priority Date Filing Date
US834735A Expired - Lifetime US3628525A (en) 1969-06-19 1969-06-19 Blood oxygenation and pulse rate monitoring apparatus

Country Status (9)

Country Link
US (1) US3628525A (en)
JP (1) JPS4917477B1 (en)
DE (1) DE2027530A1 (en)
DK (1) DK128700B (en)
FR (1) FR2052617A5 (en)
GB (1) GB1318552A (en)
IL (1) IL34454A (en)
NL (1) NL7008178A (en)
SE (1) SE365940B (en)

Cited By (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3769974A (en) * 1971-06-29 1973-11-06 Martin Marietta Corp Blood pulse measuring employing reflected red light
US3810460A (en) * 1971-10-23 1974-05-14 Philips Corp Detector for physiological quantities
US3881481A (en) * 1973-02-08 1975-05-06 Audronics Inc Left ventricular ejection meter
US3980075A (en) * 1973-02-08 1976-09-14 Audronics, Inc. Photoelectric physiological measuring apparatus
US3993047A (en) * 1974-07-10 1976-11-23 Peek Sanford C Instrumentation for monitoring blood circulation
US3998550A (en) * 1974-10-14 1976-12-21 Minolta Camera Corporation Photoelectric oximeter
US4010749A (en) * 1975-05-09 1977-03-08 Shaw Robert F Method of detecting infiltration of infused liquid by comparing altered skin temperature with skin temperature in area of infiltrated liquid
US4030485A (en) * 1974-11-12 1977-06-21 Glenfield Warner Method and apparatus for continuously monitoring systolic blood pressure
US4077399A (en) * 1976-08-03 1978-03-07 New Research And Development Laboratories, Inc. Cranial transillumination device
US4109643A (en) * 1976-06-17 1978-08-29 Hewlett-Packard Company Perfusion meter
US4183360A (en) * 1978-07-26 1980-01-15 The United States Of America As Represented By The Department Of Health, Education And Welfare Multifinger photocell plethysmography system
US4265227A (en) * 1979-10-03 1981-05-05 The Hospital And Welfare Board Of Hillsborough County Infant extremity positioner and illuminator
US4380240A (en) * 1977-06-28 1983-04-19 Duke University, Inc. Apparatus for monitoring metabolism in body organs
US4570638A (en) * 1983-10-14 1986-02-18 Somanetics Corporation Method and apparatus for spectral transmissibility examination and analysis
US4685464A (en) * 1985-07-05 1987-08-11 Nellcor Incorporated Durable sensor for detecting optical pulses
US4817623A (en) 1983-10-14 1989-04-04 Somanetics Corporation Method and apparatus for interpreting optical response data
US4840179A (en) * 1986-11-17 1989-06-20 Hellige Gmbh Combined sensor for the transcutaneous measurement of oxygen and carbon dioxide in the blood
US4877034A (en) * 1987-06-18 1989-10-31 Smith & Nephew, Inc. Method and device for detection of tissue infiltration
US4915116A (en) * 1988-07-06 1990-04-10 Misawa Homes Institute Of Research & Development Fingertip pulse wave sensor
US5140989A (en) * 1983-10-14 1992-08-25 Somanetics Corporation Examination instrument for optical-response diagnostic apparatus
DE4114357A1 (en) * 1991-05-02 1992-11-05 Mueller & Sebastiani Elek Gmbh Apnoea automatic diagnosis method using ECG signal from patient - determined over longer period from which timed course of heart frequency is computed and evaluated
US5237997A (en) * 1988-03-09 1993-08-24 Vectron Gesellschaft Fur Technologieentwicklung und Systemforschung mbH Method of continuous measurement of blood pressure in humans
US5267563A (en) * 1991-06-28 1993-12-07 Nellcor Incorporated Oximeter sensor with perfusion enhancing
US5349961A (en) * 1983-10-14 1994-09-27 Somanetics Corporation Method and apparatus for in vivo optical spectroscopic examination
US5402777A (en) * 1991-06-28 1995-04-04 Alza Corporation Methods and devices for facilitated non-invasive oxygen monitoring
EP0897691A2 (en) * 1997-08-22 1999-02-24 Kyoto Dai-ichi Kagaku Co., Ltd. Method of and apparatus for organism measurement
US6241663B1 (en) 1998-05-18 2001-06-05 Abbott Laboratories Method for improving non-invasive determination of the concentration of analytes in a biological sample
US20030028117A1 (en) * 2001-07-30 2003-02-06 Hampton Thomas G. System and method for non-invasive monitoring of physiological parameters
US6526298B1 (en) 1998-05-18 2003-02-25 Abbott Laboratories Method for the non-invasive determination of analytes in a selected volume of tissue
US6662030B2 (en) 1998-05-18 2003-12-09 Abbott Laboratories Non-invasive sensor having controllable temperature feature
US6662031B1 (en) 1998-05-18 2003-12-09 Abbott Laboratoies Method and device for the noninvasive determination of hemoglobin and hematocrit
US20040138537A1 (en) * 1999-03-10 2004-07-15 Braig James R. Solid-state non-invasive thermal cycling spectrometer
US7043287B1 (en) 1998-05-18 2006-05-09 Abbott Laboratories Method for modulating light penetration depth in tissue and diagnostic applications using same
US20060258926A1 (en) * 1999-01-25 2006-11-16 Ali Ammar A Systems and methods for acquiring calibration data usable in a pulse oximeter
US20070260131A1 (en) * 2006-05-02 2007-11-08 Chin Rodney P Clip-style medical sensor and technique for using the same
US20100016731A1 (en) * 2008-07-15 2010-01-21 Cardiox Corporation Hemodynamic Detection of Circulatory Anomalies
EP2243425A2 (en) 2005-11-30 2010-10-27 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH530006A (en) * 1970-10-01 1972-10-31 Hoffmann La Roche Electrode arrangement
EP0006966B1 (en) * 1978-03-23 1981-10-14 Hellige GmbH Device for affixing electrodes and similar biological and physiological transducers in the mouth
EP0024772B1 (en) * 1979-08-28 1984-06-13 Battelle Memorial Institute Apparatus for measuring the human being's blood pressure
GB2068537B (en) * 1980-02-04 1984-11-14 Energy Conversion Devices Inc Examining biological materials
JP4574314B2 (en) * 2004-10-06 2010-11-04 日本電信電話株式会社 Photoelectric sphygmomanometer

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706927A (en) * 1949-08-04 1955-04-26 Research Corp Apparatus for determining percentage oxygen-saturation of blood
US2790438A (en) * 1956-01-13 1957-04-30 Taplin Ronald Harold Earpieces for oximeters
US3068739A (en) * 1958-06-23 1962-12-18 American Optical Corp Flexible optical probe
US3152587A (en) * 1960-03-31 1964-10-13 Hellige & Co Gmbh F Medical photometric apparatus
US3461856A (en) * 1965-10-23 1969-08-19 American Optical Corp Oximeters

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706927A (en) * 1949-08-04 1955-04-26 Research Corp Apparatus for determining percentage oxygen-saturation of blood
US2790438A (en) * 1956-01-13 1957-04-30 Taplin Ronald Harold Earpieces for oximeters
US3068739A (en) * 1958-06-23 1962-12-18 American Optical Corp Flexible optical probe
US3152587A (en) * 1960-03-31 1964-10-13 Hellige & Co Gmbh F Medical photometric apparatus
US3461856A (en) * 1965-10-23 1969-08-19 American Optical Corp Oximeters

Cited By (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3769974A (en) * 1971-06-29 1973-11-06 Martin Marietta Corp Blood pulse measuring employing reflected red light
US3810460A (en) * 1971-10-23 1974-05-14 Philips Corp Detector for physiological quantities
US3881481A (en) * 1973-02-08 1975-05-06 Audronics Inc Left ventricular ejection meter
US3980075A (en) * 1973-02-08 1976-09-14 Audronics, Inc. Photoelectric physiological measuring apparatus
US3993047A (en) * 1974-07-10 1976-11-23 Peek Sanford C Instrumentation for monitoring blood circulation
US3998550A (en) * 1974-10-14 1976-12-21 Minolta Camera Corporation Photoelectric oximeter
US4030485A (en) * 1974-11-12 1977-06-21 Glenfield Warner Method and apparatus for continuously monitoring systolic blood pressure
US4010749A (en) * 1975-05-09 1977-03-08 Shaw Robert F Method of detecting infiltration of infused liquid by comparing altered skin temperature with skin temperature in area of infiltrated liquid
US4109643A (en) * 1976-06-17 1978-08-29 Hewlett-Packard Company Perfusion meter
US4077399A (en) * 1976-08-03 1978-03-07 New Research And Development Laboratories, Inc. Cranial transillumination device
US4380240A (en) * 1977-06-28 1983-04-19 Duke University, Inc. Apparatus for monitoring metabolism in body organs
US4183360A (en) * 1978-07-26 1980-01-15 The United States Of America As Represented By The Department Of Health, Education And Welfare Multifinger photocell plethysmography system
US4265227A (en) * 1979-10-03 1981-05-05 The Hospital And Welfare Board Of Hillsborough County Infant extremity positioner and illuminator
US5140989A (en) * 1983-10-14 1992-08-25 Somanetics Corporation Examination instrument for optical-response diagnostic apparatus
US5349961A (en) * 1983-10-14 1994-09-27 Somanetics Corporation Method and apparatus for in vivo optical spectroscopic examination
US4570638A (en) * 1983-10-14 1986-02-18 Somanetics Corporation Method and apparatus for spectral transmissibility examination and analysis
US4817623A (en) 1983-10-14 1989-04-04 Somanetics Corporation Method and apparatus for interpreting optical response data
US4685464A (en) * 1985-07-05 1987-08-11 Nellcor Incorporated Durable sensor for detecting optical pulses
US4930506A (en) * 1986-11-17 1990-06-05 Hellige Gmbh Combined sensor for the transcutaneous measurement of oxygen and carbon dioxide in the blood
US4840179A (en) * 1986-11-17 1989-06-20 Hellige Gmbh Combined sensor for the transcutaneous measurement of oxygen and carbon dioxide in the blood
US4877034A (en) * 1987-06-18 1989-10-31 Smith & Nephew, Inc. Method and device for detection of tissue infiltration
US5237997A (en) * 1988-03-09 1993-08-24 Vectron Gesellschaft Fur Technologieentwicklung und Systemforschung mbH Method of continuous measurement of blood pressure in humans
US4915116A (en) * 1988-07-06 1990-04-10 Misawa Homes Institute Of Research & Development Fingertip pulse wave sensor
DE4114357A1 (en) * 1991-05-02 1992-11-05 Mueller & Sebastiani Elek Gmbh Apnoea automatic diagnosis method using ECG signal from patient - determined over longer period from which timed course of heart frequency is computed and evaluated
DE4114357C2 (en) * 1991-05-02 2000-07-06 Mueller & Sebastiani Elek Gmbh Device for automatic detection of apnea
US5267563A (en) * 1991-06-28 1993-12-07 Nellcor Incorporated Oximeter sensor with perfusion enhancing
US5402777A (en) * 1991-06-28 1995-04-04 Alza Corporation Methods and devices for facilitated non-invasive oxygen monitoring
US5392777A (en) * 1991-06-28 1995-02-28 Nellcor, Inc. Oximeter sensor with perfusion enhancing
EP1213037A1 (en) 1992-06-03 2002-06-12 Alza Corporation Methods and devices for facilitated non-invasive oxygen monitoring
EP0897691A3 (en) * 1997-08-22 1999-09-01 Kyoto Dai-ichi Kagaku Co., Ltd. Method of and apparatus for organism measurement
EP0897691A2 (en) * 1997-08-22 1999-02-24 Kyoto Dai-ichi Kagaku Co., Ltd. Method of and apparatus for organism measurement
US6241663B1 (en) 1998-05-18 2001-06-05 Abbott Laboratories Method for improving non-invasive determination of the concentration of analytes in a biological sample
US6526298B1 (en) 1998-05-18 2003-02-25 Abbott Laboratories Method for the non-invasive determination of analytes in a selected volume of tissue
US6654620B2 (en) 1998-05-18 2003-11-25 Abbott Laboratories Method for improving non-invasive determination of the concentration of analytes in a biological sample
US6662030B2 (en) 1998-05-18 2003-12-09 Abbott Laboratories Non-invasive sensor having controllable temperature feature
US6662031B1 (en) 1998-05-18 2003-12-09 Abbott Laboratoies Method and device for the noninvasive determination of hemoglobin and hematocrit
US7043287B1 (en) 1998-05-18 2006-05-09 Abbott Laboratories Method for modulating light penetration depth in tissue and diagnostic applications using same
US20060258926A1 (en) * 1999-01-25 2006-11-16 Ali Ammar A Systems and methods for acquiring calibration data usable in a pulse oximeter
US20040138537A1 (en) * 1999-03-10 2004-07-15 Braig James R. Solid-state non-invasive thermal cycling spectrometer
US20030028117A1 (en) * 2001-07-30 2003-02-06 Hampton Thomas G. System and method for non-invasive monitoring of physiological parameters
US7065396B2 (en) 2001-07-30 2006-06-20 The Curavita Corporation System and method for non-invasive monitoring of physiological parameters
EP2243425A2 (en) 2005-11-30 2010-10-27 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose
EP2399515A2 (en) 2005-11-30 2011-12-28 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose
EP2399516A2 (en) 2005-11-30 2011-12-28 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose
EP2399517A2 (en) 2005-11-30 2011-12-28 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose
US8315681B2 (en) 2005-11-30 2012-11-20 Toshiba Medical Systems Corporation Method for noninvasive measurement of glucose and apparatus for noninvasive measurement of glucose
US20070260131A1 (en) * 2006-05-02 2007-11-08 Chin Rodney P Clip-style 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
US8437826B2 (en) 2006-05-02 2013-05-07 Covidien Lp Clip-style medical sensor and technique for using the same
US20100016731A1 (en) * 2008-07-15 2010-01-21 Cardiox Corporation Hemodynamic Detection of Circulatory Anomalies

Also Published As

Publication number Publication date
GB1318552A (en) 1973-05-31
NL7008178A (en) 1970-12-22
JPS4917477B1 (en) 1974-05-01
IL34454A0 (en) 1970-07-19
SE365940B (en) 1974-04-08
IL34454A (en) 1973-05-31
DE2027530A1 (en) 1970-12-23
DK128700B (en) 1974-06-17
FR2052617A5 (en) 1971-04-09

Similar Documents

Publication Publication Date Title
US3628525A (en) Blood oxygenation and pulse rate monitoring apparatus
US3461856A (en) Oximeters
US2706927A (en) Apparatus for determining percentage oxygen-saturation of blood
US4509522A (en) Infrared optical measurement of blood gas concentrations and fiber optic catheter
US3152587A (en) Medical photometric apparatus
US5800349A (en) Offset pulse oximeter sensor
JP3190604B2 (en) Photoplethysmograph measuring device
US4485820A (en) Method and apparatus for the continuous monitoring of hemoglobin saturation in the blood of premature infants
US4836206A (en) Method and device for determining viability of intact teeth
ATE308269T1 (en) A PROBE FOR NON-INVASIVE MEASUREMENTS OF BLOOD-RELATED PARAMETERS
JP3839202B2 (en) Biological light measuring device and program for causing this device to function
US3040737A (en) Blood pressure measuring transducer
JP2002529174A (en) Apparatus and method for measuring blood parameters
US8317701B2 (en) Device and method for intra-ocular pressure measurement
JPS6259005U (en)
JP3994588B2 (en) Noninvasive blood glucose meter
JPH0547208B2 (en)
JP2007532188A (en) Photoplethysmography using spatially uniform multicolor sources
JPH02206478A (en) Optical diagnostic apparatus
US2358992A (en) Oxygen meter
US2667159A (en) Plethysmograph
CN117224100A (en) Microcirculation monitoring device for parallel detection
US7802900B2 (en) Light reflex testing device
US20160029888A1 (en) Applanation tonometer having cornea alignment means
CA3007551C (en) Optical fiber-based spectroreflectrometric system

Legal Events

Date Code Title Description
AS Assignment

Owner name: WARNER LAMBERT COMPANY, 201 TABOR ROAD, MORRIS PLA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMERICAN OPTICAL CORPORATION,;REEL/FRAME:004034/0681

Effective date: 19820513

Owner name: WARNER LAMBERT TECHNOLOGIES, INC.; 6373 STEMMONS F

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WARNER LAMBERT COMPANY;REEL/FRAME:004034/0700

Effective date: 19820514