United States Patent
`Goodman et a1.
`
`[19]
`
`[11]
`
`[45]
`
`Patent Number:
`
`4,830,014
`
`Date of Patent:
`
`May 16, 1989
`
`2262952 10/ 1975 France .
`
`OTHER PUBLICATIONS
`
`Cohen. Amen, “Photoelectric Determination of the
`Relative Oxygenation of Blood", Carnegie-Mellon
`University, Ph.D. Thesis, 1969, (pp. 5741).
`Primary Examiner—Edward M. Coven
`Arramey, Agent, or Firm—ThOmas L. Gianneiti; Jeffrey
`1-1. Ingerman
`ABSTRACT
`[57]
`A sensor for trans-illumination of a blood perfused por-
`tion of flesh to measure light extinction during trans-
`illumination is disclosed. The sensor
`is preferably
`mounted on a fingertip but any digit or blood perfused
`portion of flesh will work. The sensor includes a first
`end for disposition on one side of the trans-illuminated
`flesh and a second end for disposition on the opposite
`and opposed side of the trans-illuminated flesh. A light
`source is mounted to the first side and a photo~sensor is
`mounted to the second side. If an elongated flexible
`strip is used. it is provided with adhesive and is suitably
`windowed that light is allowad to take an optical path
`through the finger. If no flexible strip is used. the two
`ends are aligned and secured to the flesh such that the
`light emitted takes an optical path through the finger.
`When the adhesive fastener is used, the effect of the
`light source and photo-detector substrates being inte-
`grated into the adhesive fastener is that they become, in
`effect. a part of the skin. The resulting device is resistant
`to accidental removal and avoids constriction of blood
`vessels. Most importantly, the low mass of the sensor
`itself and its conformance to. so as to effectively become
`a part of, the skin, prevents relative motion between the
`light source and sensor and the perfused flesh. This
`eliminates the common interference associated with the
`operation of conventional plethysmographs and Oidme-
`ters.
`
`2 Claims, 4 Drawing Sheets
`
`[54] SENSOR HAVING CUTANEOUS
`CONFORMANCE
`
`[‘15]
`
`Inventors: David E. Go0dman, San Francisco;
`James E. Corenman, Menio Park;
`William New, Jr., Woodside; Mark
`Yeldermzm, Menlo Park, all of Calif.
`
`[73] Assignee: Nellcor Incorporated, Hayward,
`Calif.
`
`[21] App]. No.: 70.619
`[22] Filed:
`Jul. 7, 1987
`
`[63]
`
`Related US. Application Data
`Continuation of Ser. No. 873.129. Jun. 11. 1986.313”-
`doned, which is a continuation of Ser. No. 539,365,
`Oct. 7, 1983. abandoned, which is s continuation-iti-
`part of Ser. No. 493,442. May 11, 1983, abandoned.
`
`Int. Cl.‘ .............................................. .. A611! 5/02
`[51]
`[52] US. Cl. ................................... .. 128/665; 123/666
`[58] Field of Search ............. .. 125/633. 637, 640, 644.
`128/665, 667, 664. 689, 690, 691
`
`[56}
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`
`
`128/666):
`1/1965 Richter
`3,167,653
`128/640
`3/1921 Gordy
`3,599,629
`128/105 F
`8/1971 Howell el al
`3,602,213
`.. 128/666
`3.769.974 11/1973 Smart et al
`123/690
`3.801.383 4/1924 Om eta]
`.... ..
`123/660
`4,013.06?
`3/1917 Kresse eta!
`123/666
`4,091,303
`5/1978 Pinda
`128/690
`4,305,401 12/19s1 Reissmueller a al.
`128/640
`4.350.165
`9/1982 Striese ...............
`128/640
`4310.934- 2/1983 Cartmell
`.. 128/633
`4.380.240 4/1933 Jobsis et a1.
`...... 123/690
`4,406,239 9/1983 Wesseling eta].
`FOREIGN PATENT DOCUMENTS
`671229 10/1963 Canada
`0019418 11/1930 European Pat. 61E".
`
`128/690
`
`
`
`
`
`- ‘tfl‘
`d. -‘r d. It I. H. l.-
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`“ "‘1‘ “ “ “ “ “ “
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`---
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`0001
`0001
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`Apple Inc.
`Apple Inc.
`APL1007
`APL1007
`U.S. Patent No. 8,989,830
`US. Patent No. 8,989,830
`FITBIT, EX. 1007
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`FITBIT, Ex. 1007
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`

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`US. Patent
`
`May 16,1989
`
`Sheet 1 of4
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`4,830,014
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`
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`"
`PRIOR ART
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`" F/G‘.../A.
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`FIG; [a
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` LIGHTEXTINCTION
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`TIME —_"'
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`0002
`0002
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`FITBIT, EX. 1007
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`US. Patent May16,1989
`
`Sheet 2 0“
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`4,830,014
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`0003
`0003
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`FITBIT, EX. 1007
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`FITBIT, Ex. 1007
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`

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`US. Patent
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`May 16, 1939
`
`Sheet 3 of4
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`4,830,014
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`
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`FIG..._6'A.
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`0004
`0004
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`US. Patent May 16, 1989
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`Sheet 4 of 4
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`4,830,014
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`FITBIT, Ex. 1007
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`

`1
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`4,830,014
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`2
`attachment design is easily dislodged from the finger
`either accidentally or involuntarily,
`terminating mea-
`surement prematurely and often unexpectedly.
`Alternatively, a clamp design has been used to mea-
`sure a patient’s pulse. This design consists of one or
`more light-emitting-diodes adjacent to one side of a
`fleshy appendage such as a finger. The light from the
`LEDs is received by a photo-sensor placed on the op-
`posing fleshy side of the appendage (see FIG. 1C and
`1D). This type of construction generally consists of a
`small spring-loaded clip which attaches like a common
`ciothespin to the tip of a finger or similar appendage.
`This type of sensor attachment has been used in an
`oximetcr as well as a plethysmograph. The advantage of
`the clamp type of sensor attachment is that the optical
`path traverses through the nail and entire fingertip. This
`technique optically penetrates the tissue of the patient
`more deeply than does the simple single-sided surface
`sensor discussed previously.
`This clamp type of sensor attachment suifers from
`some of the same defects as the single-sided type of
`sensor attachment in that it often yields inaccurate mea-
`surement due to distortion caused by motion artifact
`and also tends to be inadvertently removed. Further.
`the clamp type sensor attachment has one additional
`and serious drawback: The spring-loaded pressure on
`the fleshy tissue over a period of time will cause reduc-
`tion of blood flow to the tissue. Reduction of blood flow
`causes loss of pulse amplitude and thus loss of the opti-
`cal signal to be measured. To minimize this constrictive
`effect of the clamp type attachment, the sensor must be
`adjusted or repositioned frequently, generally once or
`twice per hour. This drawback makes this sensor‘s con-
`struction unacceptable for long term. uninterrupted
`measurement.
`The phenomenon of motion artifact has been men-
`tioned. Plethysmographs and oximeters operate on the
`principle that light extinction between the light scarce
`and the photo-sensor is the sum of two effects. The first
`effect is nan-variant light extinction by stationary tissue.
`This would include skin, skin pigment, bone, nail, hair
`and other non-moving components of the tissue bed
`being illuminated. Referring to FIG. 1E, one identifies
`the non-variant component 10 of light extinction from
`stationary tissue shown with fixed amplitude over time.
`The second effect of light pulsatile extinction is the
`time-variant absorption clue to pulsatile arterial blood
`supplying the illuminated tisxue bed. Referring to 11 on
`FIG. 115., one sees that this is a quasi-sinusoidal pulse
`wave riding on top of the constant component 10 of
`light extinction. It is this second component that affords
`direct and accurate measurement of oxygen saturation
`in pulsatile arterial blood flow.
`A sensor with appreciable mass or high aspect ratio is
`prone to developing relative motion betWeen the light
`source, the photo-sensor and the tissue from minor me-
`chanical disturbance. This relative motion creates con-
`comitant variations in the light
`transmission from
`source to sensor and thus grossly distorts the measure-
`ment of light extinction. When this motion oceurs, vari-
`ances of light transmission are erroneous indicators of
`light extinction. These extinction errors ultimately
`cause corresponding errors in oxygen saturation mea~
`surement, all as a result of disoontinuous contact and
`other causes of relative motion between the light
`source, the photo-sensor, and tissue. A possible profile
`of such a variant motion is shown in FIG. 1E as compo-
`nent 12.
`
`SENSOR HAVING CUTANEOUS CONFORMANCE
`
`This application is a continuation of copending
`United States patent application Ser. No. 373,129, filed
`June II, 1986, abandoned which is a continuation of
`United States patent application Ser. No. 539,865, filed
`Oct. 7, 1983, now abandoned, which was a continua-
`tion-in-part of United States patent application Ser. No.
`493,442,1'iled May ll, 1933, now abandoned.
`This invention relates to a sensor having cutaneous
`conformance. More particularly, this sensor measures
`arterial oxygen saturation using non-invasive photoe-
`lectric determination, either on a. digit or for rhinople-
`thysmography. A nasal Optical sensor having physical
`conformance to the external cutaneous layer of the
`nasal septum is disclosed.
`BACKGROUND OF THE INVENTION
`
`Non-invasive monitoring of a patient’s pulse is cem-
`mon in medical practice. One type of pulse monitor
`{plethysmograpm typically incorporates an incandesn
`cent lamp or light-emitting-diode (LED) to transillumi—
`nate, that is shine through, an area containing large
`amounts of blood. The light source is mounted to well-
`perfused flesh, such as a fingertip. Light is emitted and
`transilluminates the tissue. The amount of tight passing
`through that tissue is measured using a photosensor.
`Changes between the light emitted by the light source
`and the light received by the photo-sensor are caused by
`changes in the optical absorption of the light by the
`blood perfusing the transilluminated tissue. Either
`broad~spectrum visual light or narrow bandwidth light
`in the red or infrared wavelengths can be used. The
`absorption of certain anelengtlts is related to the oxy-
`gen saturation level of hemoglobin in the blood perfus-
`ing the transilluminated tissue. The variations in light
`absorption caused by change in oxygen saturations
`make possible direct measurement of the arterial oxygen
`content.
`
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`Instruments based on this principle have been de-
`signed that use two or more wavelengths to measure
`oxygen saturation and in Some cates pulse rate.
`A common problem with these types of oxygen sen-
`sors (oxirneters) or pulse monitors (plethysmographs) is
`the incompatibility of their physical construction with
`the anatomy of the patient. A common plethysmograph
`monitor is a bulky rectangular sensor containing both a
`light-emitting-diode and a photo-sensor spaced approxi-
`mately one quarter inch apart on the same side of the
`fleshy bottom portion of the fingertip (see FIG. 1A and
`113). This design suffers from a distortion of measure-
`ment commonly called motion artifact.
`Motion artifact is due to differential motion between
`the sensor and the patient’s finger as well as changes in
`pressure within the tissue. This type of design also suf—
`fers from poor signal pick-up during periods of low
`blood flow in the illuminated tissue. Low blood flow
`occurs when blood vessels constrict and/or when there
`is insufficient volume of circulating blood in the body.
`These conditions commonly occur during shock or
`periods of low body temperature. This particular type
`of construction has been used for measuring oxygen
`saturation with good technical results but the same
`problems with motion and loss of pulse. An additional
`problem with this design is that it is typically attached
`by a small hook and-loop strap type fastener of the type
`commonly sold under the trademark Velcro ®. This
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`3
`In FIG. 1E, the sensor has moved transiently from
`the exact place where it had been fastened. The sensor
`moves due to a combination of high inertia caused by its
`substantial mass and poor conformance with the sup—
`porting tissue. Movement of the finger by the patient or
`some external disturbance causes relative motion be-
`tween the sensor and finger. The change in light trans-
`mission created by this motion appears as a change in
`"light extinction" with time, designated as component
`12 in FIG. 1E. The measuring instrument designed to
`monitor light extinction cannot distinguish optical data
`introduced to the sensor by the relative motion of the
`sensor from the optical data introduced by blood pulsa-
`tion that the instrument is designed to analyze. Confu-
`sion of the instrument's logic inevitably results in inac-
`curate analysis of data from the oximeter and conse-
`quently erroneous measurement of oxygen saturation.
`It should be evident that in situations where the sen-
`sor has significant mass relative to the finger and does
`not conform to the skin, motion artifact occurs with
`virtually every motion of the patient. When it is remem-
`bered that the patient may be unconscious and/or un-
`dergoing body motion, this motion, producing the arti-
`factual component 12 in FIG. 1E, creates a serious
`impediment to consistent accurate measurement.
`During severe physiologic stress. such as hypotension
`(low blood pressure), hypothermia (low body tempera-
`ture). and shock (low blood flow), the bodily response is
`to constrict blood vessels (vasoconstriction) in order to
`divert blood away from the extremities and away from
`the periphery (the skin surface) to maximize blood flow
`to central vital organs (cg, brain, heart, liver, etc).
`The internal carotid arteries are the major vessels
`carrying blood to the brain.
`The nasal septum is the location of terminal branches
`of the internal carotid artery, namely, the anterior and
`posterior ethmoidal arteries. The nasal septum is recog-
`nized as an excellent place to monitor blood flow to the
`brain both because of the copious blood supply in this
`area. (to warm incoming air) and because the branches
`of the carotid artery (including the anterior and poste-
`rior etlunoidal arteries) are among the last locations in
`the human body to suffer vasoconstriction under stress
`conditions.
`Physicians have used surface mounted optical pulse
`sensors (plethysmographs) and Optical oxygen satura-
`tion sensors (oximetcrs) fastened to body appendages
`(fingers, toes, ear lobes) with great success in healthy
`patients but with less success in critically ill and com-
`promised patients. These surface sensors use two basic
`configurations. The first configuration (FIG. 1) com-
`prises a small box-shaped sensor mounted onto a pa-
`tient’s digit by a hook and-loop fastener, (e.g., the prod-
`uct sold under the trademark Velcro @. This design
`may suffer from unreliable measurement due to vaso-
`constriction and motion artifact. Motion artifact, which
`causes errant measurements, results from motion differ-
`ential between the sensor and the flesh being interro-
`gated; motion artifact can be induced by both voluntary
`and involuntary motion. Motion artifact causes rela-
`tively greater measurement errors when the desired
`pulse signal is very small during vasoconstriction.
`Vasoconstriction is a narrowing of blood vessels re-
`sulting in a diminishing volume of blood flow to the
`tissue supplied by those vessels. Vasoconstriction com-
`monly occurs when a patient suffers physiological
`shock resulting from trauma, accident,
`infection, or
`surgical complication. It also occurs when a patient,
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`4
`already in an intensive care unit. suffers further compli-
`cations or worsening condition. Reduced pulse volume
`may also occur when an anesthesiologist deliberately
`induces very low blood pressure to minimize bleeding
`for a specific surgical Operation. During vascconstric-
`tion, there is less blood for the surface type sensor to
`measure. The result is a diminishing optical pulse signal
`and a relatively greater influence of motion artifact
`errors.
`
`The second surface-type sensor configuration (FIG.
`ID) that has been used to measure pulse and oxygen
`saturation consists of a spring-loaded clip shaped much
`like a clothes pin. This sensor is provided with a light
`source on one side of the clip and a photo detector on
`the other side to measure the degree of light extinction
`during transillumination by the blood flow in the tissue
`between the two sides of the clip. This second configu-
`ration is usually more effective than the first because the
`optical path, through the nail and. the entire finger tip,
`penetrates much more deeply than the surface sensor
`(FIG.
`I); however, vasoconstriction in critically ill
`patients coupled with the occluding spring pressure of
`the clip often results in insufficient pulse amplitude to
`reliably measure pulse or blood flow. Hence even a
`deep penetration surface sensor may not be useful in a
`critically ill or compromised patient.
`SUMMARY OF THE INVENTION
`
`A sensor for transillumination of a blood perfused
`portion of flesh to measure light extinction during trans-
`illumination is disclosed. The sensor
`is preferably
`mounted on a fingertip but any digit or other blood
`perfused tissue will work. The sensor conforms to and
`with the cutaneous layer of the blood perfused portion
`of flesh upon which the sensor is placed. The sensor is
`mounted on at least one flexible substrate.
`The substrate includes a first end for disposition on
`one side of the flesh to be transilluminated and a second
`end for disposition on the Opposite and opposed side of
`the flesh to be transilluminatcd, or there may be two
`independent substrates; one disposed on one side of the
`flesh to be transilluminated and the other one to be
`disposed on the Opposite side of the flesh to be transillu—
`minated.
`A light source is mounted to the first end portion or
`first substrate and a photo-sensor is mounted to the
`second end portion or second substrate. The single
`flexible substrate may be elongated, and it may be pro-
`vided with adhesive. The sensor is suitably windowed
`that light is allowed to take an optical path through the
`finger. If no flexible strip is used, the two ends are
`aligned and secured to the flesh such that the light emit-
`ted takes an optical path through the blood perfused
`flesh. If no adhesive is used, the substrates of the sensor
`may be fastened non-adhesively, such as with gauze,
`and non-invasiver to the cutaneous layer of the flesh. to
`be transilluminatod.
`When the sensor is adhesiver fastened, the effect of
`the light source and photo-sensor being integrated into
`the adhesive fastener is that they become, in effect, a
`part of the skin. The resulting device is resistant
`to
`accidental removal and avoids constriction of blood
`vessels both internal and external. Most importantly,
`the low mass of the sensor itself and its conformance to
`the skin prevents motion. localized force, and the result-
`ing contact interruption among the light source, photo-
`sensor and flesh. This feature eliminates the common
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`5
`interference associated with the operation of conven-
`tional plethysrnographs and oxin’leters.
`The present invention is directed to providing non-
`invasive, reliable, and continuous monitoring of the
`vital signs of a patient requiring intensive care to pre-
`vent vital organ damage or reduced biopotential. A
`nasal sensor is disclosed which measures light extinction
`during transillumination of the portion of nasal septum
`perfused by the ethmoidal arteries. The photoelectrical
`_ components. a light source and a light sensor, are em-
`bedded into a. flexible adhesive substrate which is bifur-
`cated into two arms. The substrate is also provided with
`signal connections leading to a measuring device. One
`arm of the bifurcated substrate is adhesed across the
`nasal septum. The entire apparatus is designed to orient
`the optical components to align the light source and
`sensor across the patient’s nasal septum.
`At least one light source is embedded in one arm. The
`light source conforms planarly to the substrate and is
`positioned to conform to the exterior cutaneous nasal
`layer while emitting light through the septum. At least
`one light sensor. embedded in the other arm, also con-
`forms to the nose exterior and receives light which has
`transilluminated the septum.
`Transillutninating the blood-perfused portion of the
`nasal septum yields information that includes, but is not
`limited to, oxygen saturation of the hemoglobin in the
`blood flow, the volume of individual blood pulsations
`supplied, and the rate and rhythm of blood pulsations.
`An object of this invention is to disclose an apparatus
`for transiiluminating well-perfused tissue with an inter-
`rogating light path between alight source and a photo-
`sensor. According to this aspect of the invention, the
`light source and photo-sensor are separately attached to
`remote end portions of electrical or other signal carry-
`ing connections sufficiently long for both portions to
`face one another from opposite sides of the tissue. The
`light source and photosensor mounted on a common
`flexible strip may thenbe adhesiver fastened to the skin
`to transil'luminate the desired portion of perfused tissue
`that both the source and the sensor now face. This
`disclosed adhesive fastening conforms the elements of
`the apparatus so completely to the patient’s skin that
`motion artifact is eliminated. Hence, the light extinction
`measurement and resulting analysis to determine oxy-
`gen saturation and pulse rate is more accurate and less
`sensitive to interference.
`A separate attachment for the light source and the
`photo-sensor, respectively, with or without direct adhe-
`sive could also be used and may be convenient for cer-
`tain applications, such as a premature baby’s hand. Indi-
`rect adhesive fastening, such as gauze wrapped around
`the hand and secured with adhesive tape, has also been
`used. Generally, however, the single strip facilitates
`alignment and is preferred.
`A further advantage of this invention is that the plus-
`tic, flexible adhesive strip can be secured over the end
`of the fingertip. not circumferentially around the finger.
`This prevents restriction of blood flow to the tissue to
`be illuminated and measured. Only nominal pressure
`from this invention to the patient is applied locally to
`the patient on the topical skirt layer directly holding the
`light source and the photosensor. This pressure does not
`extend across or into the perfused flesh in any way.
`There is no localized force exerted upon the flesh to be
`transilluminated. In sum, the flexible adhesive strip does
`not bind the perfused flesh. Consequently, the blood
`flow being interrogated is undisturbed.
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`A further advantage of the disclosed invention is the
`intimate adherence of the light source and the photo-
`sensor to the skin. This guards against accidental re-
`moval. A sensor is disclosed which effectively becomes
`a part of the patient and is not subject to natural rejec-
`tions as might occur when a patient consciously or
`unconsciously registers and resists the tactile sense of a
`large, foreign mass attached to the skin.
`A further object of this invention is to disclose a
`process for making the apparatus. In the assembly of
`this invention, the light source and the photOsensor are
`mounted to substrates and are constructed of such small
`dimensions that both independently conform with a low
`aspect ratio to the flexible adhesive strip. This process
`also uses sequential layers of Surgical tape, opaque vi-
`nyl, and light filters. Thereafter, aperture-d, opaque
`vinyl and finally a tranSparent adhesive layer are placed
`over the entire photo-sensor. The result
`is a simple
`flexible adhesive strip apparatus which is in confor-
`mance to the blood perfused flesh, is. digit, being inter-
`rogated for blood flow.
`An advantage of this invention is that it is entirely
`disposable and thus sanitary. The resultant apparatus is
`non-invasive,
`is in full conformance to the skin and
`provides minimum interference with the motion and
`tactile sense of a patient.
`An advantage of this invention is that the anterior
`ethrnoidal artery (a branch of the major artery supply-
`ing blood to the brain} may be continuously monitored
`and measured for oxygen saturation, volume, pulse rate
`and rhythm. As the brain is one of the last organs to be
`denied blood in a critically ill or compromised patient.
`this apparatus satisfies a present need to provide infor-
`mation critical to patient treatment even under the most
`dire conditions.
`is
`it
`A further advantage of this apparatus is that
`possible to monitor the critically ill and compromised
`patient who is already on a mechanical respirator to
`establish whether the artificially respirated oxygen is
`reaching the brain. Instantaneous and accurate diagno-
`sis of arterial occlusion, among other symptoms, is now
`possible.
`'
`A further advantage is that the disclosed invention
`allows simultaneous monitoring of the critically ill pa-
`tient for arterial oxygen saturation and for pulse rate
`rhythm and amplitude. With instantaneous, simulta-
`neous and accurate measurements of a variety of vital
`signs, a physician may compare the disclosed inven-
`tion‘s measurements to aid prognosis and identify
`trends.
`Another advantage of this apparatus is that even
`under dire physiological conditions, the physiological
`housing, in which the sensor is seated, maintains consis—
`tent conditions which offers an unsurpassed monitoring
`site. A major function of the nose to the human body is
`to warm and humidify inspired air. The warming func-
`tion of the nose ensures an adequate blood supply, even
`under severe physiological stress and peripheral vaso-
`constriction (described before) that commonly impedes
`the conventional surface-type plethysmograph and on-
`imeters. Therefore. the nasal septum is an ideal location
`to make continuous and uninterrupted measurements of
`pulse and arterial saturation.
`A further advantage of this invention is that the sen-
`sor is attached to the cutaneous layer of the nasal sep-
`tum which neither invades nor interrupts the flow ofthe
`anterior and posterior ethmoidal arteries to be interro-
`gated.
`
`0008
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`FITBIT, EX. 1007
`
`FITBIT, Ex. 1007
`
`

`

`4,830,014
`
`7
`A further advantage of the disclosed invention is the
`critically ill patient’s body need not be punctured and
`exposed to the risk of infection or some other further
`endangering of his condition.
`A further advantage of the disclosed invention is the
`ability to measure oxygen saturation in the anterior and
`posterior ethmoidal arteries directly rather than indi-
`rectly. This ability to constantly measure blood oxygen
`content facilitates faster diagnosis of vital organ crises
`and makes feasible instantaneous and responsive treat~
`ment of the critically ill patient.
`A further object of this invention is to disclose a
`method for manufacturing a nasal sensor. In the assem-
`bly of this invention, the light source and the photo-sen-
`sor are embedded in a flexible plastic substrate all of 15
`which are constructed of such small dimension that the
`sensor conforms cutaneously to the patient’s external
`cutaneous layer. The assembly process entails sequen-
`tial layers of mounting. There results a apparatus easily
`affixed on the patient's nose.
`A further advantage of the disclosed external nasal
`sensor is that critical biopotential signals can be in-
`stantly and accurately received without competing for
`vital locations penetrating the nose. Interference with
`cannulaes.
`tubes, and sensing devices in the nose is
`avoided.
`A further advantage of the disclosed nasal sensor is
`that the vital biopotential information may be accu-
`rately acquired from the critically compromised patient
`by technicians or persons who have little training or
`expertise.
`A further advantage of the disclosed invention is that
`the blood flow of a critically compromised patient may
`be measured with limited risk of measurement error
`incurred by motion artifact; the foam layer between the
`adhesive and the substrate provides a tight, acupressure
`exerting, skin seal which prevents motion artifact.
`A further advantage of the disclosed invention is that
`the foam layer between the adhesive and the substrate
`provides a light—tight seal between the skin and the
`sensor,
`thus protecting the components and resulting
`measureth from the deleterious effects of ambient
`light.
`A further advantage of the disclosed invention is that
`an opaque photographic coating applied to the foam-
`/adhesive side of the flexible substrate prevents mea-
`surement inaccuracies by diminishing light refraction
`and rebound. The opaque photographic coating further
`protects against ambient light reaching the components.
`A further advantage of the disclosed invention is that
`measurement of the carotid blood flow through the
`ethmoidal cavity is more accurate when the measure-
`ment site is located at the nasal external cutaneous layer
`rather than those measurements taken from sites at the
`inner nostril cutaneous layer.
`A further advantage of the disclosed invention is that
`one size of sensing strip may be universally affixed to
`human noses. In contrast to the enormous variety of
`sizes, shapes,
`topical surface configurations of the
`human nostrils, the sizes and shapes of ridge environs of
`the human nose are relatively unvaried.
`BRIEF DESCRIPTION OF DRAWINGS
`
`10
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`20
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`25
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`30
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`35
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`45
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`55
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`60
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`8
`taping arrangement, using alight source and photo-sen-
`sot having appreciable mass which results in the defect
`herein described as motion artifact;
`FIGS. 1C and ID are diagrams of the clamping type
`sensor attachment across the digit of a patient;
`FIG. 1B is a graphical representation of an instru-
`ment view of light extinction wherein motion artifact is
`present;
`FIG. 2A is a perspective view of the sensor of this
`invention looking towards the photo-sensor, light-emit~
`ting-diodes and adhesive surface;
`FIG. 2B is a view of the sensor of FIG. 2A illustrat-
`ing various layers of this invention peeled back to ex-
`pose the inner construction disclosed herein;
`FIG. 2C is an exploded side view of the sensor
`wherein each of the composite elements of the pre-
`ferred embodiment of the substrate are individually
`shown and identified;
`FIG. 3A is a perspective view of the photosensor and
`light source used on the invention herein disclosed;
`FIG. 3B is an enlargement view of a portion of FIG.
`3A of a substrate having the light emitting diodes
`thereon;
`FIG. 3C is an enlarged view of the remaining portion
`of FIG. 3A of a substrate for supporting the photo-sen-
`sitive surface;
`FIG. 4 is a view ofa digit with the cutaneous interro-
`gating apparatus of this invention in place;
`FIG. 5 is a perspective illustration of the nasal sensor;
`FIGS. 6A and 613 are side and perspective views of
`patients with the disclosed invention in place anatomi-
`cally;
`FIG. 7 is a perspective view of the nasal sensor show-
`ing the assembly mount of the light-emitting-diode and
`of the photo-sensor with sectional enlarged views of the
`light-emitting-diodc and the photo-sensor;
`FIG. 8 is an exploded illustration of flexible substrate,
`foaml electrical component and other layers designed to
`monitor blood flow across the nasal septum; and
`FIG. 9 is a bottom plan view of a nasal sensor accord-
`ing to the invention. I
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`In the description that follows, we will first describe
`the construction of the sensor device 10 herein. There-
`after, we will set forth the attachment to the perfused
`flesh being examined.
`Referring to FIG. 3A. two substrate portions 14. 24
`are illustrated. To portion 14 is mounted a photo-sensor.
`To portion 24 are mounted the light sources of this
`invention. The light sources will be discussed first with
`respect to FIG. 3B.
`Light-emitting-diodes 25 and 26 are adhesiver fas-
`tened to a substrate 2’? as by gluing with electrically
`conductive epoxy adhesive. Very small dimensional
`light-emitting-diodes with micro circuitry can be uti-
`lized. These light-emitting~diodes will be seen by the
`reader to conform to a thin layer which is subsequently
`fastened in the plane of substrate 27.
`By way of dimensions, substrate 27 is typically 4
`mm><6 mm or such other dimensions may be used.
`Electrical cannections 28 are used and include paired
`light-emitting—diode driving conductors with a common
`ground.
`Referring to FIG. 3C, the photosensitive portion of
`device 10 can be seen. This photo-sensitive portion
`includes a substrate 11'. electrical connections 18 and a
`
`Other objects. features and advantages of this inven-
`tion will become more apparent after referring to the
`attached drawings in which:
`FIGS. 1A and 1B are perspective illustrations of the
`prior art illustrating a common hook-and-loop type
`
`65
`
`0009
`0009
`
`FITBIT, EX. 1007
`
`FITBIT, Ex. 1007
`
`

`

`4,830,014
`
`9
`photo-sensitive surface 19 adhesiver fastened to plate
`17. Again the dimensions are provided which give the
`apparatus low profile and aspect ratios.
`It should be apparent that the electrical connections
`herein disclosed can be subject to other configurations.
`For instance, an integrated chip or thin film construc-
`tion may be desirable where mass production of the
`element herein disclosed occurs.
`In the preferred embodiment as of the date of this
`disclosu