( 12 ) United States Patent
`Hotelling et al .
`
`( 10 ) Patent No .: US 11,009,390 B2
`May 18 , 2021
`( 45 ) Date of Patent :
`
`US011009390B2
`
`( 54 ) METHODS AND SYSTEMS FOR
`MODULATION AND DEMODULATION OF
`OPTICAL SIGNALS
`( 71 ) Applicant : Apple Inc. , Cupertino , CA ( US )
`Inventors : Steven P. Hotelling , Los Gatos , CA
`( 72 )
`( US ) ; Marcelo M. Lamego , Cupertino ,
`CA ( US )
`( 73 ) Assignee : Apple Inc. , Cupertino , CA ( US )
`Subject to any disclaimer , the term of this
`( * ) Notice :
`patent is extended or adjusted under 35
`U.S.C. 154 ( b ) by 428 days .
`( 21 ) Appl . No .: 15 / 960,507
`Apr. 23 , 2018
`( 22 ) Filed :
`( 65 )
`Prior Publication Data
`Aug. 23 , 2018
`US 2018/0238734 A1
`Related U.S. Application Data
`Continuation of application No. 14 / 618,664 , filed on
`Feb. 10 , 2015 , now Pat . No. 9,952,095 .
`Provisional application No. 62 / 057,089 , filed on Sep.
`29 , 2014 .
`( 51 ) Int . Ci .
`GO1J 1/44
`A61B 5/024
`GOIJ 1/18
`A61B 5/00
`
`( 63 )
`
`( 60 )
`
`( 52 ) U.S. CI .
`CPC
`
`( 2006.01 )
`( 2006.01 )
`( 2006.01 )
`( 2006.01 )
`( Continued )
`GOIJ 1/44 ( 2013.01 ) ; A61B 5/02427
`( 2013.01 ) ; A61B 5/7225 ( 2013.01 ) ; A61B
`5/7228 ( 2013.01 ) ; GOIJ 1/0228 ( 2013.01 ) ;
`GOIJ 1/18 ( 2013.01 ) ; GOIJ 2001/0257
`( 2013.01 ) ; GOIJ 2001/4242 ( 2013.01 ) ; GOIJ
`2001/444 ( 2013.01 )
`
`( 58 ) Field of Classification Search
`G01J 1/0228 ; GO1J 2001/0257 ; G01J
`CPC
`2001/4242 ; GO1J 2001/444 ; A61B
`5/7225 ; A61B 5/02427
`See application file for complete search history .
`References Cited
`U.S. PATENT DOCUMENTS
`
`( 56 )
`
`4,729,128 A
`5,162,618 A
`5,381,696 A
`
`3/1988 Grimes
`11/1992 Knowles
`1/1995 Ichinose et al .
`( Continued )
`FOREIGN PATENT DOCUMENTS
`2/1994
`11/2005
`
`WO 94/002911
`WO 05/103872
`
`WO
`WO
`
`- Brownstein Hyatt Farber
`
`OTHER PUBLICATIONS
`" Ultrasonic sensor for fingerprints recognition , ” Pro
`Bicz et al . ,
`ceedings of SPIE 2634 , Optoelectgronic and Electronic Sensors ,
`Jun . 30 , 1995 , doi : 10-1117 / 12.213142 , 9 pages .
`( Continued )
`Primary Examiner — Tony Ko
`( 74 ) Attorney , Agent , or Firm
`Schreck , LLP
`ABSTRACT
`( 57 )
`An electronic device includes one or more light sources for
`emitting light toward a body part of a user and one or more
`optical sensors for capturing light samples while each light
`source is turned on and for capturing dark samples while the
`light source ( s ) are turned off . A signal produced by the one
`or more optical sensors is filtered and demodulated produce
`multiple demodulated signals each associated with a light
`source . Each signal associated with the light source ( s ) is
`analyzed to estimate or determine a physiological parameter
`of the user .
`
`19 Claims , 7 Drawing Sheets
`
`112
`
`116
`
`122
`
`110
`
`128
`
`130
`
`132
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`US 11,009,390 B2
`Page 2
`
`( 51 ) Int . Ci .
`GOIJ 1/02
`G01 ) 1/42
`
`( 2006.01 )
`( 2006.01 )
`
`( 56 )
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`5,515,298 A
`5,589,636 A
`5,719,950 A
`5,886,452 A
`6,091,406 A
`6,159,149 A
`6,164,135 A
`6,720,712 B2
`7,032,454 B2
`7,400,750 B2
`7,449,821 B2
`7,458,268 B2
`7,497,120 B2
`7,568,391 B2
`7,656,932 B2
`7,667,374 B2
`7,734,435 B2
`7,739,912 B2
`7,770,456 B2
`8,047,995 B2
`8,054,203 B2
`8,085,998 B2
`8,095,328 B2
`8,179,678 B2
`8,201,739 B2
`8,335,356 B2
`8,345,508 B2
`8,508,103 B2
`8,536,465 B2
`8,576,202 B2
`8,601,876 B2
`8,617,078 B2
`8,666,126 B2
`8,692,812 B2
`8,724,859 B2
`8,743,091 B2
`8,781,180 B2
`8,791,792 B2
`8,982,089 B2
`9,044,171 B2
`9,056,082 B2
`9,100,034 B2
`9,132,693 B2
`9,170,668 B2
`9,201,546 B2
`9,275,625 B2
`9,323,393 B2
`9,465,972 B2
`
`5/1996 Bicz
`12/1996 Bicz
`2/1998 Osten
`3/1999 Toda
`7/2000 Kambara
`12/2000 Erikson
`12/2000 Bicz
`4/2004 Scott
`4/2006 Amano
`7/2008 Nam
`11/2008 Dausch
`12/2008 Schneider et al .
`3/2009 Schneider et al .
`8/2009 Schneider et al .
`2/2010 Durand
`2/2010 Aono et al .
`6/2010 Thomas et al .
`6/2010 Schneider et al .
`8/2010 Stevenson et al .
`11/2011 Wakabayashi et al .
`11/2011 Breed et al .
`12/2011 Setlak et al .
`1/2012 Thomas et al .
`5/2012 Yamashita et al .
`6/2012 Schneider et al .
`12/2012 Schmitt
`1/2013 Wodnicki et al .
`8/2013 Schmitt et al .
`9/2013 Hagiwara et al .
`11/2013 Tanaka et al .
`12/2013 Schneider et al .
`12/2013 Machida et al .
`3/2014 Lee et al .
`4/2014 Hecht
`5/2014 Schneider et al .
`6/2014 Bernstein
`7/2014 Schneider et al .
`7/2014 Benkley , III
`3/2015 Lim
`6/2015 Venkatraman et al .
`6/2015 Liautaud et al .
`8/2015 Oshima
`9/2015 Klootwijk et al .
`10/2015 Schneider et al .
`12/2015 Son et al .
`3/2016 Kim et al .
`4/2016 Djordjev et al .
`10/2016 Chung et al .
`
`2/2017 Naoka , II et al .
`9,568,315 B2
`2/2017 Du et al .
`9,582,705 B2
`3/2017 Yazdandoost et al .
`9,607,203 B1
`4/2017 Gozzini et al .
`9,613,246 B1
`8/2017 Yazdandoost et al .
`9,747,988 B2
`9/2017 Masson et al .
`9,750,451 B2
`10/2017 Vacca
`9,778,193 B2
`11/2017 Yazdandoost et al .
`9,824,254 B1
`1/2018 Terlizzi et al .
`9,857,872 B2
`2/2018 Yazdandoost et al .
`9,904,836 B2
`3/2018 Peng
`9,927,926 B2
`4/2018 Hotelling et al .
`9,952,095 B1
`5/2018 Guo
`9,979,955 B1
`5/2018 King et al .
`9,984,271 B1
`2/2019 Yousefpor et al .
`10,198,610 B1
`3/2019 Jin et al .
`10,241,223 B2
`4/2019 Yousefpor et al .
`10,275,633 B1
`4/2019 Yousefpor et al .
`10,275,638 B1
`6/2019 Yeke Yazdandoost et al .
`10,325,136 B1
`7/2019 Lu et al .
`10,366,269 B2
`6/2003 Kuniyasu et al .
`2003/0102777 A1
`6/2003 Peat et al .
`2003/0109993 A1
`7/2004 Scott et al .
`2004/0140735 A1
`2004/0264746 Al 12/2004 Polcha
`2006/0196271 A1
`9/2006 Jancsik et al .
`2008/0142571 Al
`6/2008 Yokozuka et al .
`2008/0175450 A1
`7/2008 Scott
`2012/0092026 A1
`4/2012 Liautaud et al .
`2013/0278111 A1 10/2013 Sammoura et al .
`2014/0070077 A1 *
`3/2014 Tsuchimoto
`
`2014/0316305 A1 * 10/2014 Venkatraman
`
`2014/0333328 A1 11/2014 Nelson et al .
`2014/0352440 A1 12/2014 Fennell et al .
`2014/0355381 A1 12/2014 Lal et al .
`2014/0359757 Al 12/2014 Sezan et al .
`2015/0053006 Al
`2/2015 DeCoux et al .
`2015/0192547 Al
`7/2015 Lee et al .
`2015/0358740 A1 12/2015 Tsai et al .
`2016/0092714 Al
`3/2016 Yazdandoost et al .
`2016/0117541 Al
`4/2016 Lu et al .
`2016/0246396 Al
`8/2016 Dickinson et al .
`2016/0350573 Al 12/2016 Kitchens , II et al .
`2017/0053151 A1
`2/2017 Yazdandoost et al .
`2017/0263022 A1
`9/2017 Teshigawara et al .
`2017/0357839 Al 12/2017 Yazdandoost et al .
`
`A61B 5/7203
`250/214 A
`A61B 5/681
`600/595
`
`OTHER PUBLICATIONS
`Gumienny et al . , “ Synthetic aperture acoustic microscope for evalu
`ation of finger tip peripheral skin structure , ” Proceedings of SPIE ,
`Optical Biophysics , Mar. 30 , 1995 , doi : 10.1117 / 12.205999 , 5
`pages .
`* cited by examiner
`
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`U.S. Patent
`
`May 18 , 2021
`
`Sheet 1 of 7
`
`US 11,009,390 B2
`
`100
`
`102
`104 -
`
`102
`
`112
`
`12-2
`O - 1145 )
`O - -114a
`
`FIG . IA
`
`FIG . IB
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`U.S. Patent
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`May 18 , 2021
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`Sheet 2 of 7
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`US 11,009,390 B2
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`114b
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`116
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`112
`
`118
`
`114a
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`120
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`122
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`124
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`126
`
`FIG . 2A
`
`112
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`116
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`122
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`110
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`128
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`130
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`
`FIG . 2B
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`May 18 , 2021
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`Sheet 3 of 7
`
`US 11,009,390 B2
`
`300
`
`LIGHT SOURCE
`CONTROLLER
`
`LIGHT SOURCE ( S )
`
`306
`
`OPTICAL SENSOR
`CONTROLLER
`
`OPTICAL SENSOR ( S )
`
`FIG . 3
`
`-302
`
`310
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`308
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`May 18 , 2021
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`Sheet 4 of 7
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`US 11,009,390 B2
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`OPTICAL SENSOR
`
`-400
`
`402
`
`404
`
`406
`
`408
`
`TRANS
`IMPEDANCE
`AMPLIFIER
`
`HIGH
`PASS
`FILTER
`
`PROGRAMMABLE
`GAIN AMPLIFIER
`
`ANALOG TO
`DIGITAL
`CONVERSION
`
`FIG . 4
`
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`May 18 , 2021
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`Sheet 5 of 7
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`US 11,009,390 B2
`
`502
`
`504
`
`SAMPLE SIGNAL AS
`MATRIX
`
`MULTIPLY MATRIX BY
`DEMULTIPLEXING
`MATRIX
`
`FIG . 5
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`May 18 , 2021
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`Sheet 6 of 7
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`US 11,009,390 B2
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`600
`
`602
`
`604
`
`606
`
`608
`
`RECEIVE CALIBRATION SIGNAL
`
`DEACTIVATE ALL LIGHT SOURCES FOR A
`SELECT PERIOD OF TIME
`
`ACTIVE SINGLE LIGHT SOURCE FOR A SELECT
`PERIOD OF TIME
`
`DEACTIVATE ALL LIGHT SOURCES FOR A
`SELECT PERIOD OF TIME
`
`SELECT NEXT LIGHT SOURCE
`
`FIG . 6
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`Sheet 7 of 7
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`US 11,009,390 B2
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`700
`
`702
`
`704
`
`704
`
`SEND CALIBRATION SIGNAL
`
`DETERMINE DEMULITPLEXING PARAMETER
`MATRIX FROM OUTPUT DATA
`
`AVERAGE OUTPUT DATA FOR SELECT
`NUMBER OF CALIBRATION PERIODS
`
`SAVE CALIBRATED DEMULTIPLEXING
`PARAMETERS
`
`FIG . 7
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`US 11,009,390 B2
`
`25
`
`30
`
`5
`
`1
`METHODS AND SYSTEMS FOR
`MODULATION AND DEMODULATION OF
`OPTICAL SIGNALS
`
`2
`Accordingly , there may be a present need for an improved
`optical sensing system configured for use with a small form
`factor health monitoring device .
`SUMMARY
`CROSS - REFERENCE TO RELATED
`APPLICATION
`Embodiments described herein may relate to , include , or
`take the form of an electronic device adapted to measures the
`This application is a continuation of U.S. patent applica-
`optical characteristics , such as reflection or transmission , of
`tion Ser . No. 14 / 618,664 , filed on Feb. 10 , 2015 , entitled
`“ Methods and Systems for Modulation and Demodulation of 10 a subject .
`Optical Signals , ” which claims the benefit under 35 U.S.C.
`Embodiments described herein may relate to , include , or
`$ 119 ( e ) of U.S. Provisional Patent Application No. 62/057 ,
`take the form of an electronic device including at least a
`filed on Sep. 29 , 2014 , and entitled “ Methods and
`housing with a surface adapted to be positioned proximate a
`Systems for Modulation and Demodulation of Optical Sig
`measurement site of a subject , a biometric sensor positioned
`nals , ” both of which are incorporated by reference as if fully 15 at least partially within the surface and including at least a
`disclosed herein .
`plurality of light sources for emitting light toward the
`measurement site and an optical sensor for obtaining light
`TECHNICAL FIELD
`exiting the measurement site . The electronic device can also
`The present invention relates generally to health moni- 20 include an input amplifier coupled to the output of the
`biometric sensor , a high pass filter coupled to the output of
`toring systems , and more particularly to health monitoring
`the input amplifier , an output amplifier coupled to the output
`devices that include one or more optical sensors .
`of the high pass filter , and an analog to digital converter
`coupled to the output of the output amplifier .
`BACKGROUND
`Further embodiments described herein may relate to ,
`include , or take the form of a sensor system including at least
`Health monitoring devices , such as fitness and wellness
`a plurality of light sources for emitting light toward a
`devices , may be capable of non - invasively measuring a
`variety of physiological characteristics of a subject via
`measurement site of a subject , an optical sensor for obtain
`optical sensing . Such health monitoring devices can include
`ing light exiting the measurement site , and an input amplifier
`a light source and an optical sensor .
`coupled to the output of the biometric sensor , a high pass
`The light source can illuminate a portion of a measure
`filter coupled to the output of the input amplifier , an output
`ment site or even emit light that penetrates beneath the
`amplifier coupled to the output of the high pass filter , and an
`measurement
`such as into the str
`corneum of the
`analog to digital converter coupled to the output of the
`skin or into blood vessels beneath the skin . Light from the
`output amplifier .
`light source may be scattered , absorbed , and / or reflected 35
`Additional embodiments described herein may relate to ,
`throughout the measurement site or the material forming the
`include , or take the form of a method of optical sensing ,
`measurement site , such as the skin . The amount of scatter ,
`including at least the operations of emitting light toward a
`absorption , or reflection can depend directly or indirectly on
`measurement site of a subject , obtaining light exiting the
`one or more physiological characteristics of the measure
`measurement site , converting the obtained light to an elec
`ment site .
`40
`trical signal , amplifying the electrical signal to obtain an
`The optical sensor can collect light exiting the measure
`ment site and generate electrical signals corresponding to the
`amplified signal , filtering low frequency elements from the
`amplified signal to obtain a filtered signal , and amplifying
`collected light , which may be conveyed ( in the form of
`the filtered signal to obtain an output signal .
`electrical signals ) as information or data to the health
`monitoring device . The health monitoring device can use the 45
`Other embodiments may include further including at least
`optical sensor data to extrapolate , determine , derive , esti-
`sampling the output signal to obtain a matrix of samples , and
`mate , or measure physiological parameters of the measure-
`determining product of the matrix of samples with a
`ment site .
`demodulation matrix to obtain a demodulated matrix . Sam
`In many cases , the optical sensor data may include noise
`pling the output signal to obtain a matrix of samples can
`associated with ambient light , surface conditions of the 50 include taking a first sample , taking a second sample , taking
`measurement site ( e.g. , cleanliness , hair , perspiration , etc. ) ,
`a third sample , subtracting the average of the first and third
`proximity of the optical sensor and / or light source to the
`sample from the second sample to obtain an output sample ,
`measurement site , and motion artifacts caused by the relative
`and inserting the output sample into the matrix of samples .
`motion between the health monitoring device and the mea-
`Other embodiments may include a configuration in which
`55 light may be emitted toward the measurement site from a
`surement site .
`Furthermore , health monitoring devices often have a
`plurality of light sources each with a light emitting diode ,
`and light may be obtained exiting by an optical sensor with
`small form factor and are wearable by a subject for extended
`periods of time . The constrained proportions of such devices
`one of the group consisting of photodiodes , phototransistors ,
`can limit the maximum physical size of the optical sensor
`or optical image sensors .
`and / or light source , effectively restricting the performance 60
`of both . For example , smaller light sources may emit less
`BRIEF DESCRIPTION OF THE DRAWINGS
`light and smaller optical sensors may detect less light . In
`addition , as the size of the optical sensor and / or light source
`Reference will now be made to representative embodi
`decrease , the effects of noise increase . As a result , the
`ments illustrated in the accompanying figures . It should be
`accuracy , precision , and / or reliability of the physiological 65 understood that the following descriptions are not intended
`parameters derived from the optical sensor data can decrease
`to limit the disclosure to one preferred embodiment . To the
`with the size of many current health monitoring devices .
`contrary , each is intended to cover alternatives , modifica
`
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`US 11,009,390 B2
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`10
`
`15
`
`3
`4
`eters , blood glucose sensors , body weight sensors , body fat
`tions , and equivalents as may be included within the spirit
`sensors , blood alcohol sensors , dietary sensors , and so on .
`and scope of the described embodiments as defined by the
`appended claims .
`Certain sensors can collect certain health - related infor
`mation non - invasively . For example , a health monitoring
`FIG . 1A depicts a top plan view of an example health
`monitoring device .
`5 device can include a sensor that is configured to measure
`changes in light absorption of a measurement site of the
`FIG . 1B depicts a bottom plan view of the health moni-
`subject . Such a sensor can be implemented as an active
`toring device of FIG . 1A , showing apertures associated with
`sensing system including a light emitter and a light detector .
`an optical sensing system .
`In one embodiment the sensing system can include a light
`FIG . 2A depicts a detailed cross - section of FIG . 1B taken
`source for emitting light into a measurement site of a subject
`along line 2-2 , showing a simplified view of the optical
`sensing system of FIG . 1B .
`and an optical sensor to detect light exiting the measurement
`site . Light from the light source may be scattered , absorbed ,
`FIG . 2B depicts the detailed cross - section of FIG . 2A ,
`and / or reflected throughout the measurement sight as a
`showing a set of example light paths from a light source
`function of various physiological parameters or character
`through a measurement site of a subject to an optical sensor
`of the optical sensing system .
`istics of the subject . For example , a subject may be a human
`user and the measurement site may be the user's wrist . In
`FIG . 3 depicts a simplified signal flow diagram of an
`optical sensing system .
`such an example , the tissue of the user's wrist can scatter ,
`absorb , or reflect light emitted by the light source differently
`FIG . 4 depicts a simplified signal flow diagram of ampli-
`20 depending on various physiological characteristics of the
`fication and filtering stages of an optical sensing system .
`surface and subsurface of the user's wrist . In other
`FIG . 5 depicts a simplified signal flow diagram of a
`examples , a subject can be an animal .
`demodulation stage of an optical sensing system .
`For example , some embodiments may be configured to
`FIG . 6 depicts example operations of a method of cali-
`detect various subsurface events , such as the user's cardiac
`brating an optical sensing system performed by a light
`25 cycle . More particularly , during each complete heartbeat , a
`source controller .
`user's subcutaneous tissue can distend and contract , alter
`FIG . 7 depicts example operations of a method of cali-
`natingly increasing and decreasing the light absorption
`brating an optical sensing system performed by an optical
`sensor controller .
`capacity of the measurement site . In these embodiments , the
`The use of the same or similar reference numerals in
`optical sensor can collect light exiting the measurement site
`different drawings indicates similar , related , or identical 30 and generate electrical signals corresponding to the collected
`items where appropriate .
`light . Thereafter , the electrical signals can be conveyed as
`data to the health monitoring device . One may appreciate
`DETAILED DESCRIPTION
`that such a sensor is conventionally referred to as a photop
`Embodiments described herein relate to systems and 35 lethysmographic sensor ( hereinafter “ PPG sensor ” ) .
`As noted above , the performance optical sensors such as
`methods for increasing the signal to noise ratio of an optical
`PPG sensors can be negatively affected by noise associated
`sensing system configured for use with a small form factor
`with ambient light , surface conditions of the measurement
`health monitoring device , although the various systems and
`methods described herein are not limited to particular form
`site ( e.g. , cleanliness , hair , perspiration , etc. ) , proximity of
`factors and can apply equally to larger embodiments . Fur- 40 the optical sensor and / or light source to the measurement
`ther , it should be appreciated that the various embodiments
`site , and motion artifacts caused by the relative motion
`described herein , as well as functionality , operation , com-
`between the health monitoring device and the measurement
`ponents , and capabilities thereof may be combined with
`site . In other words ,
`“ environmental noise ” can have a
`other elements as necessary , and so any physical , functional ,
`substantial impact on the quality of the data obtained by the
`or operational discussion of any element or feature is not 45 optical sensor .
`intended to be limited solely to a particular embodiment to
`Accordingly , many embodiments described herein modu
`late the light output from the light source and demodulate the
`the exclusion of others .
`Any suitable type of electronic device can include health
`light collected by the optical sensors . In this manner , envi
`monitoring functionality . Example electronic devices
`ronmental noise can be at least partially prevented from
`include , but are not limited to , a smart telephone , a headset , 50 interfering with the operation of the optical sensor . In many
`a pulse oximeter , a digital media player , a tablet computing
`embodiments , modulation and demodulation can be imple
`device , a timekeeping device , a peripheral input device ( e.g. ,
`mented by toggling the light source on and off at a particular
`keyboard , mouse , trackpad ) , and a wearable device . Elec-
`frequency . Thereafter , the optical sensor can generate elec
`tronic devices that include health monitoring functionality
`trical signals corresponding to the light collected from the
`are generally referred to herein as “ health monitoring 55 measurement site . In these embodiments , the electrical sig
`devices ” or “ health devices ” and the like . Accordingly , it is
`nals can be demodulated and processed by the health moni
`toring device .
`understood that a health monitoring device as described
`herein is not necessarily limited to devices configured to
`In many embodiments , the health monitoring device can
`only provide health - related information , rather , a health
`implement a time - domain noise attenuation operation such
`monitoring device may include other functionality as well . 60 as dark - channel subtraction . For example , in some embodi
`In one embodiment , one or more sensors may be included
`ments , a sample can be taken from the optical sensor when
`within the health monitoring device . Sensors utilized by a
`it is known that the light source is not emitting light . This
`health monitoring device can vary from embodiment to
`sample can be saved as a “ dark ” sample . Thereafter , a
`embodiment . Suitable sensors can include temperature sen-
`sample can be taken from the optical sensor when it is
`sors , electrodermal sensors , blood pressure sensors , heart 65 known that the light source is emitting light . Next , the dark
`rate sensors , respiration rate sensors , oxygen saturation
`sample can be subtracted from this “ light ” sample to remove
`sensors , plethysmographic sensors , activity sensors , pedom-
`the effects of noise from the light sample . In other words , a
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`MASIMO 2024
`Apple v. Masimo
`IPR2022-01291
`
`

`

`US 11,009,390 B2
`
`5
`6
`third parties , and / or an associated monitoring device . The
`dark sample can represent an approximation of the amount
`wearable health assistant may be configured to provide
`of environmental noise at or near the time the dark sample
`health - related information or data such as , but not limited to ,
`was taken .
`heart rate data , blood pressure data , temperature data , blood
`In further embodiments , a second dark sample can be
`taken after the light sample . In such cases , the first and 5 oxygen saturation level data , diet / nutrition information ,
`second dark samples can be averaged . The averaged dark
`medical reminders , health - related tips or information , or
`sample may be subtracted from the intervening light sample
`other health - related data . The associated monitoring device
`in order to remove the effects of noise from the light sample .
`may be , for example , a tablet computing device , phone ,
`Although time - domain noise attenuation operations such
`personal digital assistant , computer , and so on .
`as dark - channel subtraction may be suitable in certain 10
`As another example , the health monitoring device can be
`embodiments for mitigating the effects of certain environ-
`configured in the form of a wearable communications
`mental noise sources , the delays required between “ light ”
`device . The wearable communications device may include a
`samples ( e.g. , delays where dark samples are required to be
`processor coupled with or in communication with a memory ,
`taken ) can cause undesirable aliasing . In some examples ,
`one or more sensors , one or more communication interfaces ,
`using dark - channel subtraction may require a reduction in 15 output devices such as displays and speakers , one or more
`sampling rate , which in turn can increase the number of
`input devices , and a health monitoring system . The com
`aliases present in the data output from the optical sensor . In
`munication interface ( s ) can provide electronic communica
`these examples , low frequency aliases may be particularly
`tions between the communications device and any external
`communication network , device or platform , such as but not
`undesirable .
`For example , many physiological signals measurable by a 20 limited to wireless interfaces , Bluetooth interfaces , USB
`interfaces , Wi - Fi interfaces , TCP / IP interfaces , network
`PPG sensor ( e.g. , respiration , heart rate ) are relatively low
`frequency signals . For example , a heathy user's heart rate
`communications interfaces , or any conventional communi
`may vary from less than one beat per second to only a few
`cation interfaces . The wearable communications device may
`beats per second . In other words , a heart rate may be a
`provide information regarding time , health , statuses or exter
`physiological signal within the frequency band from 0 Hz to 25 nally connected or communicating devices and / or software
`3-4 Hz . Accordingly , low frequency aliasing ( as a result of
`executing on such devices , messages , video , operating com
`dark - channel subtraction ) can interfere with the detection
`mands , and so forth ( and may receive any of the foregoing
`and extraction of low frequency physiological signals , such
`from an external device ) , in addition to communications .
`The health monitoring device 100 includes a housing 102
`as heart rate .
`Accordingly , certain embodiments described herein 30 at least partially surrounding a display 104. In many
`implement a filter prior to time - domain noise attenuation .
`examples , the display 104 may incorporate an input device
`For example , a high pass or a band pass filter can be
`configured to receive touch input , force input , and the like
`implemented to att nuate some or all frequencies except
`and / or output information to a user , such as various health
`frequencies nearby the modulation frequency . In this man-
`parameters or health - related suggestions . The health moni
`ner , certain frequencies of environmental noise can be 35 toring device 100 may also include one or more buttons or
`attenuated prior to time - domain noise attenuation operations
`input devices ( not shown ) . The housing 102 can form an
`such as dark - channel subtraction . As a result , low frequency
`outer surface or partial outer surface and protective case for
`noise sources are attenuated and , accordingly , the negative
`the internal components of the health monitoring device
`effects of low frequency aliasing can be reduced .
`100. In the illustrated embodiment , the housing 102 is
`Although filtering prior to dark - channel subtraction may 40 formed into a substantially rectangular shape , although this
`be suitable in some embodiments for attenuating certain
`configuration is not required .
`noise sources , the process of filtering with a dynamic filter
`The housing 102 can be formed of one or more compo
`( such as a band pass or high pass filter ) can increase the
`nents operably connected together , such as a front piece and
`complexity of demodulating and / or demultiplexing the sig-
`a back piece or a top clamshell and a bottom clamshell .
`nal . For example , the time response of a dynamic filter can 45 Alternatively , the housing 102 can be formed of a single
`mix the time - multiplexed signals sent from the light source
`piece ( e.g. , uniform body or unibody ) operably connected to
`in time . In other words , dynamic filtering of a signal S.
`the display 104 .
`received at time to can cause the signal S , to interfere with
`The display 104 can be implemented with any suitable
`technology , including , but not limited to , a multi - touch
`a signal S , sent at time t? .
`Accordingly , embodiments described herein relate to 50 sensing touchscreen that uses liquid crystal display ( LCD )
`methods and systems for demodulating and demultiplexing
`technology , light emitting diode ( LED ) technology , organic
`signals output from an optical sensor implementing both
`light - emitting display ( OLED ) technology , organic elec
`dynamic filtering and time - domain noise attenuation .
`troluminescence ( OEL ) technology , or another type of dis
`FIG . 1A depicts a top plan view of an example health
`play technology . A button ( not shown ) might take the form
`monitoring device 100. In the illustrated embodiment , the 55 of a home button , which may be a mechanical button , a soft
`health monitoring device may be implemented as a portable
`button ( e.g. , a button that does not physically move but still
`electronic device that is adapted to be worn by a user . Other
`accepts inputs ) , an icon or image on the display 104 or on
`embodiments can implement the health monitoring device
`an input region , and so on . Other buttons or mechanisms can
`differently . For example , the health monitoring device can
`be used as input / output devices , such as a speaker , rotary
`be a smart phone , a gaming device , a digital music player , 60 input , a microphone , an on / off button , a mute button , or a
`sleep button .
`a sports accessory device , a medical device , a device that
`provides time and / or weather information , a health assistant ,
`The health monitoring device 100 may include one or
`and other types of electronic device suitable for attaching to
`more health sensors . In some examples , the health sensors
`can be disposed on a bottom surface 112 of the housing 102 .
`a user .
`The health monitoring device can be implemented as a 65 For example , FIG . 1B depicts a bottom plan view of the
`health monitoring device of FIG . 1A , showing two apertures
`wearable health assistant that provides health - related infor-
`mation ( whether real - time or not ) to the user , authorized
`114a , 114b associated with an optical sensing system that
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`MASIMO 2024
`Apple v. Masimo
`IPR2022-01291
`
`

`

`US 11,009,390 B2
`
`7
`8
`embodiment , the lens 120 can be configured to diffuse light ,
`can be used to obtain health - related information from a user .
`while in other embodiments it may focus light or may not
`As noted above , an optical sensing system can include a
`affect the directionality of light passing therethrough . In
`light source and an optical sensor ( not shown ) . The light
`some embodiments , the lens 120 may be optically transpar
`source can be disposed within a first aperture 114a and the
`optical sensor can be disposed within a second aperture 5 ent . In still further embodiments , the lens 120 may be
`114b . In some embodiments , the light source may fill the
`configured to exhibit transparency in a first light frequency
`first aperture and / or the optical sensor may fill the second
`band and to be opaque in a second light frequency band . For
`aperture , while in other embodiments optically - transparent
`one example , the first light frequency band can be infrared
`windows or covers may seal the light source and optical
`light and the second light frequency band can be visible
`sensor in their respective apertures . As used herein , the term 10 light .
`“ optically transparent ” and variants thereof does not neces-
`As with the light source 116 , the optical sensor 122 can be
`sarily mean that the structure is transparent to visible light
`disposed within a cavity 124 and below another window or
`but instead to the particular wavelength of light emitted by
`lens 126. As with the lens 120 , the lens 126 can be
`the light source and / or received by the sensor . Thus , some
`configured to diffuse light . In other embodiments , the lens
`windows may pass infrared light but block visible light and 15 126 may be optically transparent , or may be shaped to focus
`still be optically transparent .
`light to a particular focal point ( or not ) . In still f