OVEANAA
`(11) Patent Number:
`5,490,523
`United States Patent .
`[45] Date of Patent:
`Feb. 13, 1996
`Isaacson etal.
`
`
`[54] FINGER CLIP PULSE OXIMETER
`[75]
`Inventors: Philip O. Isaacson, Chanhassen, David
`W. Gadtke, Plymouth; Timothy L.
`Johnson, Medina, all of Minn.
`
`[73] Assignee: Nonin Medical Inc., Plymouth, Minn.
`
`[21] Appl. No.: 268,202
`[22] Filed:
`Jun. 29, 1994
`
`6
`Tint, C9ceceseeenterteacnnennnnes
`[51]
`
`[52] US. Cd. neeeesseseensssscrnseeeeeneeceeensennnnnncnntnnnaret 128/633
`
`[58] Field of Search ......
`... 128/633, 664-667,
`356/39-41
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`4,129,124 12/1978 Thalmann...ees: 128/666
`10/1982 O’Conmoret al.
`4,353,152
`wn. 128/666 X
`
`4,394,572
`7/1983 Wilber .
`4,446,715
`5/1984 Bailey .
`.
`4,621,643
`11/1986 New,Jr. et al.
`4,653,498
`3/1987 New, Jr. et al..
`4,685,464
`8/1987 Goldberg et al. «0... 128/664 X
`4,700,708
`12/1987 New,Jr. et al.
`.
`4,765,340
`8/1988 Sakai et al. uses 128/633
`4,770,179
`9/1988 New, Jr. et al. .
`4,773,422
`9/1988 Isaacson et al. .
`4,825,872
`5/1989 Tan elal. .
`4,825,879
`5/1989 Tan et al.
`.
`4,830,014
`5/1989 Goodman etal. .
`4,848,901
`7/1989 Hood, Jr.
`.
`.
`4,865,038
`9/1989 Rich et al.
`4,928,691
`5/1990 Nicolson et al. .
`
`.
`
`.
`
`4,964,408 10/1990 Hinketal. .
`4,971,062
`11/1990 Hasebe et al. .
`5,035,243
`7/1991 Muz.
`.
`5,041,187
`8/1991 Hink et al.
`5,069,213
`12/1991 Polezynski .
`.
`5,080,098
`1/1992 Willett et al.
`5,170,786 12/1992 Thomas et al.
`5,188,108
`2/1993 Secker.
`5,209,230
`5/1993 Swedlow et al.
`5,217,012
`6/1993 Young etal. .
`ssvsesssreeseenrn 128/666 X
`5,217,013
`6/1993 Lewis et al.
`
`. 128/666 X
`5,224,478
`7/1993 Sakai etal.
`5,237,994
`8/1993 Goldberger .
`5.246.003
`9/1993 DeLonzor.
`5,247,931
`9/1993 Norwood .....sesocesseeeeeseeens 128/665 X
`§,249,576
`10/1993 Goldbergeret al.
`.
`5,279,295
`1/1994 Martenset al.
`.
`5,313,940
`5/1994 Fuse et aboscents 128/664 X
`B1 4,446,715
`9/1991 Bailey .
`OTHER PUBLICATIONS
`McDermott; “Fitness and Health Care Products Incorporate
`Advanced Electronics”; Technology News—EDN; Sep.
`1980, vol. 25, No. 17, pp. 69-77.
`
`Primary Examiner—Angela D. Sykes
`Attorney, Agent, or Firm—Vidas, Arrett & Steinkraus
`
`ABSTRACT
`[57]
`The invention is directed to Apparatus for measuring a
`physical parameter, such as the saturation percentage of
`oxygen in blood. The pulse oximeteris built into the finger
`clip, and therefore the device is small, lightweight and very
`portable, as well as more reliable.
`
`11 Claims, 12 Drawing Sheets
`
`001
`
`Apple Inc.
`APL1204
`U.S. Patent No. 9,289,135
`
`Apple Inc.
`APL1204
`U.S. Patent No. 9,289,135
`
`001
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`5,490,523
`
`Sheet 1 of 12
`
`002
`
`002
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 2 of 12
`
`5,490,523
`
`Fig. 7
`
`003
`
`003
`
`

`

`U.S. Patent
`
`Sheet 3 of 12
`
`Feb. 13, 1996
`
`5,490,523
`
`004
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 4 of 12
`
`5,490,523
`
`74
`
`i
`
`Fig. 14
`
`LED 4
`
`LED 2
`
`82
`
`POWER
`
`84
`
`DISP
`
`LAY
`
`78
`
`PHOTODETECTOR
`
`ANALOG SpO
`+ PULSE CICUITRY
`
`80
`
`AAP
`
`70
`
`86
`
`COMMUNICATIONS
`
`PERFUSION
`LED
`
`85
`
`72
`
`PROGRAM
`
`005
`
`005
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 5 of 12
`
`5,490,523
`
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`Sheet 6 of 12
`
`5,490,523
`
`Feb. 13, 1996
`
`U.S. Patent
`
`007
`
`007
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 7 of 12
`
`5,490,523
`
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`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 8 of 12
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`5,490,523
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`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 9 of 12
`
`5,490,523
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`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 10 of 12
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`5,490,523
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`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 11 of 12
`
`5,490,523
`
`TO TURN ON
`
`ONCE PER SECOND
`
`Fig.18
`
`90
`
`WAKE UP
`
`92
`
`PULSE LIGHT
`AND MEASURE
`PHOTODIODE
`
`94
`
` INCREASE
`FROM MAXIMUM
`REFERENCE?
`
`YES
`
`98
`
`RESPONSE
`
`
`
`
`
`REFERENCE
`
`100
`
`GO BACK TO SLEEP
`
`SIGNIFICANT
`DECREASE?
`
`YES
`
`TURN ON
`
`104
`
`012
`
`012
`
`

`

`U.S. Patent
`
`Feb. 13, 1996
`
`Sheet 12 of 12
`
`5,490,523
`
`Fig.19
`
`90
`
`TO TURN OFF
`
`ONCE PER SECOND
`
`PULSE LIGHT
`AND MEASURE
`PHOTODIODE
`
`94
`
`RESPONSE
`
`
`
`110
`
` CLOSE
`TO MAXIMUM
`REFERENCE?
`
`YES
`
`
`FOR
`
`10 SECONDS
`
`RESET 10
`
`SECOND
`TIMER
`
`114
`
`YES
`
`112
`
`
`
`
`
`
`TWO
`
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`WITHOUT GOOD
`DATA?
`
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`
`CONTINUE
`
`013
`
`116
`
`
`
`RESET
`MAXIMUM
`REFERENCE
`
`418
`
`TURN OFF
`GO TO SLEEP
`
`013
`
`

`

`3,490,523
`
`1
`FINGER CLIP PULSE OXIMETER
`
`FIELD OF THE INVENTION
`
`This invention relates generally to medical instrumenta-
`tion, and more particularly to a finger clip sized pulse
`oximeter for measuring and indicating the percentage of one
`or more constituents of arterial blood.
`
`BACKGROUNDOF THE INVENTION
`
`Pulse oximetry devices in the past have utilized a sensor,
`generally attached to the finger, which is conductively
`coupled to an electronic device which actually measures and
`indicates the percentage of the desired constituent ofarterial
`blood.
`
`Examples of pulse oximeters using a conductively
`attached sensor would include U.S. Pat. Nos. 5,279,295;
`§,035,243; 5,217,012; 5,249,576; 5,245,003; 5,209,230;
`5,170,785; 5,080,098; 5,069,213; 5,041,187; 4,971,052;
`4,964,408; 4,928,691, 4,865,038; 4,830,014; 4,825,879;
`4,825,872; 4,770,179; 4,700,708; 4,553,498, and 4,621,643.
`Applicant also has a patent on a pulse oximeter which
`utilizes a conductively attached sensor, U.S. Pat. No. 4,773,
`422, reissued as RE. 33,543. The entire contents of U.S. Pat.
`No. 4,773,422, issued Sep. 27, 1988 arc hereby incorporated
`by reference. Applicant’s patent pulse oximeter is embodied
`in several products,
`including the Model 8600 Portable
`Pulse Oximeter and the Model 8500 Hand Held Pulse
`Oximeter.
`
`Despite achieving great commercial success with its line
`of pulse oximeters, applicant has recognized several prob-
`lems with existing pulse oximeters, including their own.
`First, the units are still very bulky and difficult to easily
`transport from one location to another. These units are
`typically bought from patient to patient, rather than being in
`a stationary location. Applicants’ units, particularly its hand
`held model 8500 are often used in connection with ambu-
`lances and are moved about a great deal. Secondly, the
`flexible conductive cable used by all existing pulse oxime-
`ters to attach the sensor frequently gets damaged due to
`being wrapped around the pulse oximeter unit during trans-
`port from one location to another. Despite many failsafes
`built
`into the cable at either end, over time the cable
`connections fail,
`
`Whatis needed is a more portable compact pulse oximeter
`which climinates the flexible conductive cable connecting
`the sensor to the pulse oximeter.
`
`SUMMARY OF THE INVENTION
`
`Applicants’ have invented a pulse oximeter which incor-
`porates the electronic processing componentandthe display
`into the sensor itself, eliminating the need for a separate
`component attached to the sensor by a flexible conductive
`cable. This finger clip pulse oximeter is extremely small,
`lightweight and durable compared to existing pulse oxime-
`ters. It is so small and lightweight that it can be carried
`around the users neck like a whistle. The inventive finger
`clip pulse oximeter is battery operated.
`The finger clip itself operates like existing finger clips,
`having an upper and lower portions which are pivotally
`connected suchthat as a finger is inserted into the finger clip,
`the two portions lift apart and pivot to evenly grip the finger.
`Whena finger is inserted into the finger clip pulse oximeter,
`the device automatically turns fully “on”, measures, calcu-
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`30
`
`55
`
`60
`
`65
`
`2
`lates and displays the measured saturation percentage of O,
`(SpO,) on a small display carried on the fingerclip.
`These and other advantages and features which charac-
`terize the invention are pointed out with particularity in the
`claims annexed hereto and forming a further part hereof.
`However, for a better understanding of the invention,
`its
`advantages and objects obtained by its use, reference should
`be made to the drawings which form a further part hereof,
`and the accompanying descriptive matter, in which there is
`illustrated and described a preferred embodiment of the
`invention.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`In the drawings, wherein like reference numerals repre-
`sent like parts throughout the several views:
`FIG. 1 is a side view of the inventive finger clip pulse
`oximeter;
`FIG. 2 is a front view of the inventive finger clip pulse
`oximeter;
`FIG. 3 is a top view of the inventive finger clip pulse
`oximeter;
`FIG.4 is a bottom view of the inventive finger clip pulse
`oximeter;
`FIG. 5 is a perspective side view showing a finger being
`inserted into the finger clip;
`FIG. 6 is a perspective side view of the inventive finger
`clip showing the finger fully inserted into the finger clip;
`FIG. 7 is an exploded perspective side view of the
`inventive finger clip;
`FIG. 8 is a perspective side view showing the spring
`disengaged from the lower housing
`FIG. 9 is a perspective view showing the two housings
`unconnected from each other;
`FIG. 10 is an alternative embodiment of the inventive
`pulse oximeter in which the invention is contained in a
`single housing, which is contoured to accept a finger pad
`pressed against the housing;
`FIG. 11 is a front view showing another alternative
`embodiment of the inventive pulse oximeter in a single
`housing contoured for the forehead;
`FIG. 12 is a side view of the embodiment of FIG. 11;
`FIG. 13 is an alternative of the spring of the preferred
`embodiment;
`FIG. 14 is a generalized block diagram of the pulse
`oximeter circuitry;
`FIG. 15 is a circuit board layout of the top side of the
`circuit board;
`FIG.16 is a circuit board layout of the bottom side of the
`circuit board;
`FIG. 17 is a detailed circuit schematic of the pulse
`oximeter circuitry;
`FIG. 18 is a flowchart of the program which monitors
`photodiode measurements and fully turns “on” the pulse
`oximeter, and
`FIG. 19 is a flowchart of the program which turns the
`pulse oximeter “off”.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`While this invention may be embodied in many different
`forms, there are described in detail herein specific preferred
`embodiments of the invention. This description is an exem-
`
`014
`
`014
`
`

`

`5,490,523
`
`3
`plification of the principles of the invention and is not
`intendedto limit the invention to the particular embodiments
`illustrated.
`
`Referring now to FIGS. 1-4,the preferred embodimentof
`the finger clip pulse oximeter is shown generally at 10.
`Fingerclip pulse oximeter takes the form offirst and second
`housings 12 and 14, which are interconnected with spring
`16. Spring 16 has ends 18 and 19 which fit into two holes 20
`and 21 on either side of the second housing 14. Spring 16 is
`comprised of two generally U-shaped spring elements,
`which are themselves connected in a side by side manner
`with a short spring elementsection 22, as is best seen in FIG.
`7. As can be seen best in FIGS. 1 and 4, spring element 22
`fits into groove 24 of the bottom of the first housing.
`Housing 12 has indents 26 and 28 which pivotally receive
`the tabs 30 and 32 of housing 14. Spring 16 allows the two
`housings 12 and 14 to pivot and/or separate relative to one
`another. Cord 34 is optionally provided to allow the finger
`clip pulse oximeter to be hung around the neck of the user.
`FIG, 2 shows opening 36, which is formed by the contours
`providedin the top of the first housing 12 and the bottom of
`the second housing 14. Opening 36 receives the inserted
`finger, and the finger clip pulse oximeter pivots and sepa-
`rates to grippingly receive the finger and position the pulse
`oximeter 10 for reading the pulse and blood oxygen satu-
`ration of the patient.
`FIG. 3 shows the top view of the finger clip pulse
`oximeter 10 in which reference numeral 38 indicates the
`display which displays the sensed and determined pulse and
`blood oxygen saturation of the patient (SpO,), each being
`positioned next to their respective legend 40 and 42. Perfu-
`sion indicator 44 is a multicolored LED which flashes green
`with each pulse amplitude when the reading is within a
`normal range (percent modulation of infrared light is more
`than 0.24%), flashes red when the pulse amplitude is too
`small
`(percent modulation of infrared light is less than
`approximately 0.08%), and flashes yellow (by tuming on
`both the green and red simultaneously) when the pulse
`amplitude is marginal. Raised ridges 46 and 48 are provided
`to better aid in holding the device.
`Finger clip pulse oximeter 10 is very portable due toits
`light weight and small size. The preferred embodiment
`weighs approximately 2.2 ounces and its dimensions are
`approximately 1.3 inches wide by 1.3 inches high by 2.2
`inches long.
`Referring now to FIGS. §, finger clip pulse oximeter 10 is
`shown with the second (or upper) 14 housing pivoted with
`respect to the first (or lower) housing 12 to enlarge opening
`36 to enable insertion of the finger of a patient. Spring 16
`provides an urging force which forces the two housings to
`the closed position shown in FIG.1.
`Referring now to FIG. 6, after the user releases the finger
`clip pulse oximeter from the position shown in FIG. 5, the
`spring 16 causes the iwo housings 12 and 14 to uniformly
`grip the inserted finger. Depending onthesize ofthe inserted
`finger, spring 16 can lift the U-shaped spring end of the
`second housing, causing the two housings to separate from
`one another.
`
`Referring now to FIG. 7, an exploded side perspective
`view of the preferred embodimentof the inventive finger
`clip pulse oximeter 10 is shown. The upper or second
`housing is shown generally at 14. Reference numeral 50 is
`a two sided surface mounted circuit board which contains
`the electronic circuitry for determining the pulse and blood
`saturation level; drives the display LED’s; drives the radia-
`lion emitting LED’s; drives the indicator 44 and controls the
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`30
`
`55
`
`60
`
`65
`
`4
`photodiode which measures the radiation received from the
`radiation emitting LED’s. Circuit board 50 will be discussed
`in more detail below. Opening 52 in the bottom of the second
`housing provides access to the radiation emitted by the
`radiation emitting LED’s which is received by the photo-
`diode mounted on the bottom side of the circuit board 50
`(discussed further below). Circuit board 50 is electrically
`connected to the first housing, shown generally at 12 via
`ribbon cable 54 which allows power and control signals to
`be sent between the two housings. First housing also holds
`batteries 56 which are used to power both the two radiation
`emitting LED’s 58 and 60 and circuit board 50. Opening 62
`in the top of the first housing allowsthe radiation emitted by
`LED’s 58 and 60 to be directed towards the photodiode
`opening 52.In the preferred embodiment, the two openings
`52 and 62 are positioned directly opposite each other.
`Referring now to FIG. 8, spring 16 is shown unconnected
`to the first housing 12. Spring 16 is designed to allow section
`22 to be released from the groove in the bottom of the lower
`section 12, which allows the spring 16 to pivot around ends
`18 and 19. As shownbest in FIG. 9, the two housings may
`now be separated for ease of cleaning, since they are only
`attached via flexible ribbon cable 54.
`It should be understood that the location of the various
`electronic elements in the preferred embodimentis a matter
`of design choice. For example, the batteries could be located
`in the second housing, or the circuit board could be located
`in thefirst housing. The only important consideration for use
`with this embodiment (a transmissive type pulse oximeter)
`is that the photodiode and radiation emitting LED’s must be
`in separate housings.
`Referring now to FIG. 10, by utilizing a reflective type
`pulse oximeter, for example of the type disclosed in U.S.
`Pat. No. 5,224,478, all of the components can be located in
`a single housing §5, either the first or second housing, if
`desired. As is well known in the art, with a reflective type
`pulse oximeter both the photodiode which receives the
`radiation and the LED’s which emitthe radiation are located
`proximate to each other. FIG. 10 shows an alternate embodi-
`ment utilizing a reflective type pulse oximeter, in which the
`pulse oximeter is housed in a single housing. Rather than
`using the two housingsto actas a fingerclip, the user simply
`presses the pad oftheir finger against the contoured surface
`to obtain the reading.
`Similarly, FIG. 11 and 12 show another alternate embodi-
`mentof the pulse oximeter which uses a reflective type pulse
`oximeter housed in a single housing which is contoured to
`form fit to the forehead of the patient.
`FIG. 13 shows an alternate embodiment of spring 16
`which includes an additional loop in the U of the U-shaped
`spring elements for additional resiliency.
`Referring now to FIGS. 14 through 17, the electronic
`circuit board 50 is discussed in greater detai]. The electronic
`circuit board is described generally in connection with the
`block diagram in FIG. 14. The corresponding circuit board
`layout, both top and bottom, are shown in FIGS. 15 and 16
`and the corresponding detailed schematic diagram is shown
`in FIG. 17. In lieu of describing the invention’s operation
`relative to the detailed circuitry, the following description
`will proceed with respect to the generalized block diagram
`of FIG. 5, with periodic mention, as necessary,
`to the
`corresponding FIGS. 15-17.
`The microprocessor is shown at block 70 (circuit element
`U1), which is a single chip microprocessor, a Motorola
`MC68HC705C8EN in the preferred embodiment, contains
`its own one time programmable read only memory
`
`015
`
`015
`
`

`

`5,490,523
`
`5
`(OTPROM)and RAM. The programming, shown at refer-
`ence numeral 72, discussed in FIGS. 18-19 is stored in the
`OTPROM memory contained inside the single chip micro-
`processor. The two radiation emitting LED’s are shown at
`blocks 74 and 76 and are controlled by the microprocessor.
`The photodetector is shown at block 78 (circuit element PDL
`in FIG. 16) in FIG. 14. The analog circuitry for conditioning
`the signal received by the photodetectoris at block 80. In the
`preferred embodiment, the particular apparatus and method
`of determining the pulse and blood oxygen saturation per-
`centage utilize the technique described in U.S. Pat. No.
`4,773,422, reissued as RE. 33,643, which will] not be dis-
`cussed in great detail here. It should be understood that any
`available technique for determining pulse and blood oxygen
`saturation percentage can be utilized by the inventive finger
`clip pulse oximeter.
`Power is provided to the microprocessor through the
`flexible ribbon cable 54, shown at block 82 in FIG. 14. The
`circuit schematic of FIG. 17 shows six LED’s, which make
`up the display. These six LED’s can be seen carried by the
`top of the circuit board 50. Three of the LED’s are used to
`display the pulse measured and three LED’s are used to
`display the sensed and measured saturation percentage of O,
`(SpO,). The display portion of the circuitry is shown at
`block 84 of FIG. 14. Block 85 in FIG. 14 represents the
`circuitry for controlling the perfusion LED (reference
`numeral 44 in FIG. 3). Finally, block 86 represents com-
`monly available communications circuitry (not shown in
`FIGS. 15-17) for providing for remote display of the pulse
`or blood oxygen saturation percentage, either conductively
`coupled or wirelessly coupled to the remote display.
`Referring now to FIG. 18, the flowchart corresponding to
`the program which monitors the photodiode and tums “on”,
`wakes up or shifts the device from a low power mode to a
`normal operating power modeis shown. Using this program
`and the apparatus, the inventive pulse oximeter eliminates
`the need for an “on” switch. Block 90 represents a prede-
`termined timeinterval, one second in the preferred embodi-
`ment, at which time the device turns fully “on”or “wakes up
`”shownat 92 sufficiently to emit radiation from one or both
`of the LED’s 58 and 60, represented at block 94. The
`program measures the photodiode response at 94 and deter-
`mines at 96 whether the light measurement represents an
`increase from the maximum measurementreference level,
`stored by the program.If the evaluationis “tyes” then the last
`measured value replaces the reference level and the device
`returns to a low powerstate, shown respectively at 98 and
`100. If the cvaluation is “no” then the program determines
`at 102 whether the decreasein light measured is a significant
`decrease from the previous value measured, which is 40 mV
`which represents a 5 times decrease in the preferred embodi-
`ment. If the decrease is not significant the device retums to
`a low power state at 100. However, if the decrease is
`significant,
`this is an indication that a finger has been
`inserted, interfering with the radiation emitted by the LED’s,
`and therefore turns the device “on”or shifts it to a normal
`operating state at 104, which also triggers the pulse and
`blood oxygen saturation determination and display. Block
`102 allows the device to be moved from a lighter area to a
`darker area without triggering the device to wake up, and
`thereby waste power.
`For the embodiments which utilize the reflective type
`pulse oximeter, the program would be modified to monitor
`for a significant increase in light rather than a significant
`decrease, since no light wouldbe reflected unless a finger or
`other body part, such as a forehead, where in place.
`Referring now to FIG. 19, the flowchart corresponding to
`the program which monitors the photodiode and turns “off”,
`
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`puts to sleep or shifts the device from a normal operating
`power modeto a low power mode is shown. Block 90, once
`per second,
`is determined by the microprocessor timing.
`Block 94 is the same as in FIG. 18. In order to determine
`when to put the device to sleep, the program evaluates the
`light measured by the photodiode to determineif is within a
`predetermined threshold value compared to the maximum
`reference value discussed above, shownat block 110. In the
`preferred embodimentthe threshold value would be 2 times
`(2X) or 50%.
`If the measured light
`is not within the
`permitted range compared to the maximumthetimer (block
`90) is reset for 10 seconds, shown at block 112,since this is
`an indication that the finger, foreheadetc.is still in place and
`the device is still operating. If the measured light is within
`the permitted range, and remains so for at least 10 seconds,
`shownat block 114, the maximumreference is reset, shown
`at block 116, and the device is returned to sleep, tumed off,
`or put in its low power mode at block 118. If the measured
`light is not within the permitted range for 10 seconds (block
`114), this indicates light level fluctuations. The program
`continues to monitor for two minutes (block 120) andif it
`does not receive good data during those two minutes,i.e. 10
`seconds within the permitted range,
`the device is pul
`to
`sleep, otherwise the device continues to measure the light
`received by the photodiode every second.
`The above Examples and disclosure are intended to be
`illustrative and not exhaustive. These examples and descrip-
`tion will suggest many variations and alternatives to one of
`ordinary skill in this art. All these alternatives and variations
`are intended to be included within the scope of the attached
`claims. Those familiar with the art may recognize other
`equivalents to the specific embodiments described herein
`which equivalents are also intended to be encompassed by
`the claims attached hereto.
`Whatis claimed is:
`1, Apparatus for measuring the blood oxygensaturation of
`arterial blood inside a body portion, comprising:
`gripping means for releasably gripping a body portion,
`wherein the gripping means is comprised of finger
`gripping meansfor releasably gripping a finger;
`a pulse oximeter means for sensing and determining the
`blood oxygen saturation of the arterial blood inside the
`gripped body portion, the pulse oximeter means being
`completely carried by the gripping means;
`a display meansfor displaying the sensed and determined
`physical parameter, the display means being attached to
`the gripping means;
`power means for providing power to the pulse oximeter
`means and the display means; and
`program meansoperatively connected to the pulse oxime-
`ter means and display means for sensing the presence
`of a finger and switching the apparatus from a low
`powerstate to a normal powerstate.
`2. The apparatus of claim 1 wherein the program means
`senses the absence of a finger and switches the apparatus
`from a normal powerstate to a low powerstate to conserve
`power.
`3. The apparatus of claim 2 including transmission means
`for transmitting the determined blood oxygen saturation
`level to a remote display.
`4. The apparatus of claim 3 wherein the transmission to
`the remote display is wireless.
`§. The apparatus of claim 1 wherein the program means
`switches the apparatus from a normal powerstate to a low
`powerstate after a predetermined time interval to conserve
`power.
`
`016
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`

`

`5,490,523
`
`25
`
`8
`7
`computation means for determining the blood oxygen
`6. Apparatus for measuring the blood oxygen saturation of
`saturation level, connected to the photosensor
`arterial blood inside a body portion, comprising:
`means,
`gripping means for releasably gripping a body portion,
`power means for providing power to the radiation
`wherein the gripping means is comprised of finger
`emitting means and a display means, and
`gripping means
`for
`releasably gripping a finger,
`a display meanscarried by the housing for displaying the
`wherein the finger gripping means comprises:
`blood oxygen saturation level determined by the pulse
`a first housing;
`oximeter means.
`a second housing; and
`9. A pulse oximeter, comprising:
`pivot meansinterconnecting the first and second hous-
`ings for allowing the first and second housings to 19_pulse oximeter meansfor sensing and determining blood
`pivot relative to one another to releasably grip a
`oxygen saturation in the arterial blood in a body
`finger inserted between the first and second hous-
`portion, the pulse oximeter means being in a normally
`ings, the pivot meansbeing constructed and arranged
`low powerstate, and wherein the pulse oximeter means
`to allow the first and second housings to separate
`is constructed and arranged for sensing and determin-
`from oneanother, wherein the pivot meansurges the !5
`ing the blood oxygen saturation in the arterial blood of
`two housings towards each other, thercby applying
`a forehead; a
`.
`pressure to releasably grip the finger
`inserted
`power conservation means operatively connected to the
`between the first and second housings and wherein
`pulse oximeter means for sensing the presence ofthe
`the pivot meansis a spring means comprised of two
`body portion and which switches the pulse oximeter
`generally U-shaped spring elements, each generally 20
`from a low power state to a normal power state,
`whereby the pulse oximeter means senses and deter-
`U-shaped spring element having an upper end and a
`mines the blood oxygen saturation in the arterial blood
`lower end, the two lower ends being connected in a
`in the body portion.
`side by side manner a predetermined distance apart
`10. A medical device of the type being housedin first and
`by an elongate spring element such that
`the two
`second housings, each housing being generally rectangular
`generally U-shaped spring elements are positioned
`shaped having back, front, top, bottom and side ends and
`on either side of the first and second housings and
`wherein the two housings are connected by a pivot means
`oriented such that the open end of the generally
`such that the two housings are stacked one on top of the
`U-shaped spring elements faces in the same direction
`other, the improvement comprising:
`as the finger receiving ends ofthe first and second
`housings, and wherein the upper ends of the spring 3°
`a pivot means wherein the pivot means is a spring means
`means are pivotally attached to the sides ofthe first
`comprised of two generally U-shaped spring elements,
`housing and the elongate spring elementis releasably
`each generally U-shaped spring element having an
`received by a groove in a botiom of the second
`upper end and a lower end, the two lower ends being
`housing, wherebythe first and second housings pivot
`connected in a side by side manner a predetermined
`and separate relative to one another to grippingly 35
`distance apart by an elongate spring element such that
`receive a finger inserted between thefirst and second
`the two generally U-shaped spring elements are posi-
`housings, and where the first and second housings
`tioned on either side of the first and second housings
`may be unconnected from one another for ease of
`and oriented such that the open end of the generally
`cleaning by releasing the elongate spring element
`U-shaped spring elements faces towards the front wall
`from the groove in the bottom of the second housing, 4°
`of the ends of the first and second housings, and
`enabling the spring meansto pivot around its upper
`wherein the upper ends of the spring means are pivot-
`ends:
`ally attached to the sides of the first housing and the
`a pulse oximeter means for sensing and determining the
`elongate spring element is releasably received by a
`blood oxygen saturation ofthe arterial blood inside the s
`groove in the bottom of the second housing, whereby
`the first and second housings may be unconnected from
`gripped body portion, the pulse oximeter means being
`one another for ease of cleaning by releasing the
`completely carried by the gripping means; and
`elongate spring element from the groove in the bottom
`a display meansfor displaying the sensed and determined
`of the second housing, enabling the spring means to
`physical parameter, the display meansbeing attached to
`pivot around its upper ends.
`the gripping means.
`50-11. Apparatus for measuring a physical parameter, com-
`7. The apparatus of claim 6 wherein each generally
`prising:
`U-shaped spring element
`includes an additional
`loop to
`gripping means for releasably gripping a body portion;
`increase the resilience in the spring means.
`electronic means for sensing and determining a physical
`8. A pulse oximeter, comprising:
`parameter, carried by the gripping means;
`a housing having a portion of its outer surface contoured 55
`power meansfor providing powerto the electronic means,
`to receive the forehead of a patient pressed againstthe
`and
`housing;
`pulse oximeter means for sensing and determining the
`blood oxygen saturation of the arterial blood inside the
`forehead,
`the pulse oximeter means carried by the
`housing and further comprising:
`radiation emitting means for directing radiation of at
`least two discrete wavelengths through the arterial
`blood inside the forehead;
`photosensor means for intercepting radiation reflected
`by the arterial blood inside the forehead;
`
`non-mechanical automatic on/off means operatively con-
`nected to the electronic means which non-mechanically
`senses the presence of a body portion gripped by the
`gripping means and switches the apparatus from a low
`power state to a normal power state, whereby the
`apparatus senses and determines the physical param-
`eter.
`
`60
`
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`
`017
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`017
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`

`

`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`PATENTNO.
`
`: 5,490,523
`
`DATED
`: Feb. 13, 1996
`INVENTOR(S) : Philip 0. Isaacson, et al
`
`It is certified that error appears in the above-indentified patent and that said Letters Patent is hereby
`corrected as shownbelow:
`
`;
`
`Col. 1, line 26, delete "33,543" and insert -- 33,643 --
`
`-
`
`Signed and Sealed this
`Twenty-third DayofApril, 1996
`
`Anest:WSsence Chie
`
`Auesting Officer
`
`Cammisstoner of Patents and Trademarks
`
`BRUCE LEHMAN
`
`018
`
`018
`
`