as) United States
`a2) Patent Application Publication co) Pub. No.: US 2014/0275854 Al
`(43) Pub. Date: Sep. 18, 2014
`
`Venkatramanet al.
`
`US 20140275854A1
`
`(54)
`
`WEARABLE HEART RATE MONITOR
`
`(71)
`
`Applicant: Fitbit, Inc., San Francisco, CA (US)
`
`(72)
`
`Inventors: Subramaniam Venkatraman, Walnut
`Creek, CA (US); Shelten Gee Jao Yuen,
`Berkeley, CA (US)
`
`(73)
`
`Assignee: Fitbit, Inc., San Francisco, CA (US)
`
`(21)
`
`Appl. No.: 14/295,059
`
`(22)
`
`Filed:
`
`Jun. 3, 2014
`
`(63)
`
`(60)
`
`Related U.S. Application Data
`
`Continuation of application No. 14/292,673, filed on
`May 30, 2014, which is a continuation-in-part of ap-
`plication No. 13/924,784, filed on Jun. 24, 2013.
`
`Provisional application No. 61/662,961, filed on Jun.
`22, 2012, provisional application No. 61/752,826,
`filed on Jan. 15, 2013, provisional application No.
`61/946,439,filed on Feb. 28, 2014, provisional appli-
`cation No. 61/955,045, filed on Mar. 18, 2014, provi-
`sional application No. 61/973,614, filed on Apr. 1,
`2014, provisional application No. 61/830,600, filed on
`Jun. 3, 2013, provisional application No. 62/001,624,
`
`filed on May 21, 2014, provisional application No.
`62/001,585, filed on May 21, 2014.
`Publication Classification
`
`(51)
`
`(2006.01)
`(2006.01)
`(2006.01)
`
`Int. Cl.
`AGIB 5/00
`AGIB 5/11
`AGIB 5/0205
`(52) U.S.CL
`CPC veesecceeseen AGIB 5/721 (2013.01); A61B 5/0205
`(2013.01); A6IB 5/1118 (2013.01); A6IB
`5/681 (2013.01); A6IB 5/742 (2013.01); AGIB
`5/1123 (2013.01)
`USPC veesssseseessessseseeee 600/301; 600/508; 600/479
`
`ABSTRACT
`(57)
`A biometric monitoring device is used to determine a user’s
`heart rate by using a heartbeat waveform sensor and a motion
`detecting sensor. In some embodiments, the device collects
`collecting concurrent output data from the heartbeat wave-
`form sensorand outputdata from the motion detecting sensor,
`detects a periodic component of the output data from the
`motion detecting sensor, and uses the periodic componentof
`the output data from the motion detecting sensor to remove a
`corresponding periodic componentfrom the output data from
`the heartbeat waveform sensor. From this result, the device
`maydetermine andpresentthe user’s heart rate.
`
`Attachment Band
`
`Buttons
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`Device Housing
`(Steel, Aluminum,
`Plastic, etc.)
`
`Sensor
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`Protrusion
`Charger
`Mating
`
`Recess
`
`
`
`Securement Method:
`Hook and Loop
`Clasp
`Band Shape Memory
`
`APPLE 1006
`
`APPLE 1006
`
`1
`
`

`

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`Patent Application Publication
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`Sep. 18,2014 Sheet 9 of 29
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`
`
`Band-Mounted Optical
`Sensors and Light
`Emitters
`
`“Figure 6A
`
`Display
`
`Wristband
`
`
`
`
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`Heart Rate Detection.
`Sensors and/or
`Emitters
`
`—
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`Figure 6B
`
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`Patent Application Publication
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`Sep. 18, 2014 Sheet 10 of 29
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`Patent Application Publication
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`Sep. 18,2014 Sheet 11 of 29
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`User-Set Alarm Window
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`Patent Application Publication
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`Sep. 18, 2014 Sheet 12 of 29
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`Patent Application Publication
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`Sep. 18,2014 Sheet 13 of 29
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`US 2014/0275854 Al
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`Light Source
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`
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`Patent Application Publication
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`Sep. 18,2014 Sheet 14 of 29
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`Patent Application Publication
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`Sep. 18,2014 Sheet 15 of 29
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`

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`Patent Application Publication
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`Sep. 18,2014 Sheet 16 of 29
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`Heart Rate
`Sensor
`
`Communication Circuitry
`(e.g., wireless radio)
`
`
`
`Processor
`
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`
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`
`17
`
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`Patent Application Publication
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`Sep. 18,2014 Sheet 17 of 29
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`Optical
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`Motion
`Signal
`
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`
`
`
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`
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`
`Figure 14B
`
`18
`
`18
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`Patent Application Publication
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`Sep. 18,2014 Sheet 18 of 29
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`US 2014/0275854 Al
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`Application
`
`Sensor 3A
`Sensor 3B
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`
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`

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`
`
` Stroke
`
`Detection
`
`Stroke Type
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` Turn
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`
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`
`Update Summary of
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`
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`
`User
`
`Finished
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`
`Figure 15A
`
`20
`
`20
`
`

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`Patent Application Publication
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`Sep. 18,2014 Sheet 20 of 29
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`US 2014/0275854 Al
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`Detection
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`Detection
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`Detection
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`
`
`
`Stroke Type 4Detection|Stroke Count
` Metrics
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`Update Summary of
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`User
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`Figure 15B
`
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`

`Patent Application Publication
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`Sep. 18,2014 Sheet 21 of 29
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`US 2014/0275854 Al
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`Detection
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`Stroke Count
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`Update Summary of
`Metrics
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`Detection
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`
`
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`User
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`Figure 15C
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`

`Patent Application Publication
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`Sep. 18,2014 Sheet 22 of 29
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`US 2014/0275854 Al
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`
`
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`Stroke Count
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`Detection
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`User
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`Figure 15D
`
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`Sep. 18,2014 Sheet 23 of 29
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`US 2014/0275854 Al
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`Differential
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`Patent Application Publication
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`Sep. 18, 2014 Sheet 24 0f 29
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`Trigger 2
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`Patent Application Publication
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`Sep. 18,2014 Sheet 25 of 29
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`Figure 16G
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`Patent Application Publication
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`Sep. 18,2014 Sheet 26 of 29
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`US 2014/0275854 Al
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`Differential
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`Figure 16J
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`Patent Application Publication
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`Sep. 18, 2014 Sheet 27 of 29
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`US 2014/0275854 Al
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`Sep. 18,2014 Sheet 29 of 29
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`US 2014/0275854 Al
`
`Sep. 18, 2014
`
`WEARABLE HEART RATE MONITOR
`
`SUMMARY
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] This application is a continuation of U.S. patent
`application Ser. No. 14/292,673,
`titled “WEARABLE
`HEART RATE MONITOR?”andfiled on May 30, 2014 (At-
`torney Docket No. FTBTP002X1JUS), which is a continua-
`tion-in-part of U.S. patent application Ser. No. 13/924,784,
`titled
`“PORTABLE
`BIOMETRIC MONITORING
`DEVICES AND METHODSOF OPERATING SAME”and
`
`filed on Jun. 24, 2013 (Attorney Docket No. FTBTP002US),
`which claims benefit of priority under 35 U.S.C. §119(e) to
`USS. Provisional Patent Application No. 61/662,961, titled
`“WIRELESS PERSONAL BIOMETRICS MONITOR”and
`filed on Jun. 22, 2012 (Attorney Docket No. FTBTP002PUS)
`and
`61/752,826,
`titled “PORTABLE MONITORING
`DEVICES AND METHODSOF OPERATING SAME”and
`
`(Attorney Docket No.
`2013
`15,
`Jan.
`on
`filed
`FTBTP002P2US); this application also claims benefit ofpri-
`ority under 35 U.S.C. §119(e) to U.S. Provisional Patent
`Application No. 61/830,600,
`titled “PORTABLE MONI-
`TORING DEVICES AND METHODS OF OPERATING
`
`SAME”and filed on Jun. 3, 2013 (Attorney Docket No.
`FTBTP002X1PUS), 61/946,439,
`titled “HEART RATE
`DATA COLLECTION?”andfiled on Feb. 28, 2014 (Attorney
`Docket No. FTBTP002X1APUS), 61/955,045, titled “GPS
`POWER CONSERVATION USING ENVIRONMENTAL
`
`DATA”and filed on Mar. 18, 2014 (Attorney Docket No.
`FTBTP002X1DPUS), 61/973, 614, titled “GPS ACCURACY
`REFINEMENT USING EXTERNAL SENSORS”andfiled
`on Apr. 1, 2014 (Attorney Docket No. FTBTP002X1EPUS),
`62/001,624,
`titled “FITNESS MONITORING DEVICE
`WITH ALTIMETER”andfiled on May 21, 2014 (Attorney
`Docket No. FTBTP002X1HPUS), and 62/001,585, titled
`“WEARABLE HEART RATE MONITOR”andfiled on May
`21, 2014 (Attorney Docket No. FTBTP002X1GPUS), all of
`which are hereby incorporated by reference herein in their
`entireties.
`
`BACKGROUND
`
`[0002] Recent consumerinterest in personal health has led
`to a variety of personal health monitoring devices being
`offered on the market. Such devices, until recently, tended to
`be complicated to use and were typically designed for use
`with one activity, e.g., bicycle trip computers.
`[0003] Recent advances in sensor, electronics, and power
`source miniaturization have allowed the size of personal
`health monitoring devices, also referred to herein as “biomet-
`ric tracking”or “biometric monitoring”devices, to be offered
`in extremely small sizes that were previously impractical. For
`example, the Fitbit Ultra is a biometric monitoring device that
`is approximately 2" long, 0.75" wide, and 0.5" deep; it has a
`pixelated display, battery, sensors, wireless communications
`capability, power source, and interface button, as well as an
`integrated clip for attaching the device to a pocket or other
`portion of clothing, packaged within this small volume.
`[0004] The disclosure provides methods and devices for
`activating, in energy efficient ways, HR monitor based on
`user motion and skin proximity. The disclosure also provides
`methods for operating the LED and photo detector of heart
`rate monitors to obtain accurate readingofheart rate tailored
`for different user characteristics such as skin colors.
`
`[0005] One aspect of the disclosure provides methods of
`determining a user’s heart rate when wearing a biometric
`monitoring device having a plurality of sensors including a
`heartbeat waveform sensor and a motion detecting sensor.
`The methods may remove motion artifacts from heartbeat
`waveform signals when determining a user’s heart rate. The
`methods may be characterized by the following operations:
`(a) collecting concurrent outputdata from the heartbeat wave-
`form sensorand outputdata from the motion detecting sensor,
`wherein the output data from the heartbeat waveform sensor
`provides information aboutthe user’s heart rate and wherein
`the output data from the motion detecting sensor provides
`information about the user’s periodic physical movements
`other than heartbeats; (b) determining a periodic component
`ofthe output data from the motion detecting sensor; (c) using
`the periodic component of the output data from the motion
`detecting sensor to remove a corresponding periodic compo-
`nent from the output data from the heartbeat waveform sen-
`sor; (d) determining the user’s heart rate; and (e) presenting
`the user’s heart rate. In some implementations, the motion
`detecting sensor is an accelerometer or a gyroscope. In some
`embodiments, the heartbeat waveform sensor may be a pho-
`toplethysmography sensor or an ECGsensor.
`[0006]
`In certain embodiments, the method contains an
`additional operation of removing a harmonic of the corre-
`sponding periodic componentfrom the output data from the
`heartbeat waveform sensor. In such embodiments, the peri-
`odic componentof the output data from the motion detecting
`sensor may be a fundamental frequency produced from the
`user’s periodic movement.
`In certain embodiments,
`the
`operation removing a corresponding periodic component
`from the output data from the heartbeat waveform sensor
`includes applying an adaptivefilter to the output data from the
`heartbeat waveform sensor and the output data from the
`motion detecting sensor. In certain embodiments, removing a
`corresponding periodic componentfrom the output data from
`the heartbeat waveform sensor includes the operation apply-
`ing an adaptive filter function to the output data from the
`motion detecting sensor that minimizes the difference
`between the output data from the heartbeat waveform sensor
`and the output data from the motion detecting sensor.
`[0007]
`In some implementations, the method includes the
`following additional operations: (i) determining the user’s
`activity level and/oractivity type; and(11) determining param-
`eters of the function based on the user’s activity level and/or
`activity type.
`[0008]
`In some implementations, the method includes the
`following additional operations: (1) analyzing the output data
`from the motion detecting sensor to infer that the user is
`substantially stationary; and (ii)
`temporarily suspending
`operation (c).
`[0009]
`Insome method implementations,the operation col-
`lecting the output data from the heartbeat waveform sensor
`includesthe following operations: (i) pulsing a light source in
`the worn biometric monitoring device ata first frequency; and
`(11) detecting light from the light sourceatthe first frequency.
`Pulsing the light source at the first frequency may involve
`emitting a succession oflight pulses of substantially constant
`intensity.
`Incertain embodiments, presenting the user’s heart
`[0010]
`rate includes presenting the heart rate on the worn biometric
`monitoring device. In certain embodiments, presenting the
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`user’s heart rate includes presenting the heart rate on an
`external device that periodically communicates with the worn
`biometric monitoring device.
`
`[0011] Another aspect ofthe invention pertains to wearable
`fitness monitoring devices designed or configured to remove
`motion artifacts from heartbeat waveform signals when deter-
`mining a user’s heart rate. Such devices may be characterized
`by the following features: a motion sensor configured to
`provide output corresponding to motion by a user wearing the
`fitness monitoring device; a heartbeat waveform sensor; and
`control logic. The control logic includes instructionsfor: (a)
`collecting concurrent output data from the heartbeat wave-
`form sensorand output data from the motion detecting sensor,
`wherein the output data from the heartbeat waveform sensor
`provides information about the user’s heart rate and wherein
`the output data from the motion detecting sensor provides
`information about the user’s periodic physical movements
`other than heartbeats; (b) determining a periodic component
`of the output data from the motion detecting sensor; (c) using
`the periodic component of the output data from the motion
`detecting sensor to remove a corresponding periodic compo-
`nent from the output data from the heartbeat waveform sen-
`sor; (d) determining the user’s heart rate; and (e) presenting
`the user’s heart rate.
`
`[0012] The control logic is typically, though not necessar-
`ily, located on thefitness monitoring device. It may be imple-
`mented as hardware, software, firmware, or any combination
`thereof. The data used by the control logic in executing the
`instructions described herein may be stored (e.g., buffered)
`by associated memory, registers, and the like, which may be
`entirely resident on the device orpartially resident on a paired
`secondary device. Examples of suitable architectures for
`implementing the control logic are presented below with
`referenceto, e.g., FIGS. 11A-G, 12A-C, 13A-B, and 14A-D.
`
`In some devices, the motion detecting sensor is an
`[0013]
`accelerometer or a gyroscope. In certain embodiments, the
`device’s heartbeat waveform sensor is a photoplethysmo-
`graphic sensor having (i) a periodic light source,(11) a photo
`detector positioned to receive periodic light emitted by the
`light source after interacting with the user’s skin, and (iti)
`circuitry determining the user’s heart rate from output of the
`photo detector. In some implementations, the photoplethys-
`mographic sensor includes two periodic light sources strad-
`dling the photo detector. In some implementations, the pho-
`toplethysmographic sensor additionally includes a housing
`having a recess in which the photo detector is disposed. The
`housing of the photoplethysmographic sensor may have a
`second recess in which the periodic light source is disposed.
`In some designs, the housing protrudes at least about 1 mm
`above a base surface of the wearable fitness monitoring
`device arranged to press against the user’s skin when worn.
`Further,
`the photoplethysmographic sensor further may
`include a spring configured to resist compression when the
`protruding housing presses against the user’s skin.In certain
`embodiments,
`the photoplethysmographic
`sensor
`also
`includes an IMLfilm overthe photo detector andthe periodic
`light source. In certain embodiments,
`the periodic light
`source is an LED.
`
`In some embodiments, the device’s control logic
`[0014]
`includes instructions for removing a harmonic ofthe corre-
`sponding periodic component from the output data from the
`heartbeat waveform sensor; in such cases the periodic com-
`
`ponent of the output data from the motion detecting sensor
`may be a fundamental frequency produced from the user’s
`periodic movement.
`for
`the instructions
`[0015]
`In some implementations,
`removing a corresponding periodic componentfrom the out-
`put data from the heartbeat waveform sensorinclude instruc-
`tions for applying an adaptivefilter to the output data from the
`heartbeat waveform sensor and the output data from the
`motion detecting sensor.
`In some implementations,
`the
`instructions for removing a corresponding periodic compo-
`nent from the output data from the heartbeat waveform sensor
`include instructions for applying an adaptive filter function to
`the output data from the motion detecting sensor that mini-
`mizes the difference between the output data from the heart-
`beat waveform sensor and the output data from the motion
`detecting sensor.
`[0016]
`In certain embodiments, the device’s control logic
`additionally includes instructions for:
`(4) determining the
`user’s activity level and/or activity type; and (11) determining
`parameters of the function based on the user’s activity level
`and/oractivity type. In certain embodiments, the controllogic
`further comprises instructions for: (1) analyzing the output
`data from the motion detecting sensorto infer that the useris
`substantially stationary; and (ii)
`temporarily suspending
`execution of the instructions of(c).
`[0017]
`In some implementations, the instructions for col-
`lecting the output data from the heartbeat waveform sensor
`include instructionsfor: (1) pulsing a light source in the worn
`biometric monitoring device at a first frequency; and (ii)
`detecting light from the light source at the first frequency. The
`instructions for pulsing the light sourceat thefirst frequency
`may include instructions for emitting a succession of light
`pulses of substantially constantintensity.
`[0018]
`In some cases, the instructions for presenting the
`user’s heart rate includeinstructions for presenting the heart
`rate on the worn biometric monitoring device. In somecases,
`the instructions for presenting the user’s heart rate include
`instructions for presenting the heart rate on an external device
`that periodically communicates with the worn biometric
`monitoring device.
`[0019] Another aspect of this disclosure concerns methods
`of determining a user’s heart rate when wearing a worn bio-
`metric monitoring device including a plurality of sensors
`including a heartbeat waveform sensor and a motion detect-
`ing sensor. The methods involve a pre-processing operation
`prior to motion compensation. The methods may be charac-
`terized by the following operations: (a) collecting concurrent
`output data from the heartbeat waveform sensor and output
`data from the motion detecting sensor, wherein the output
`data from the heart beat waveform sensor provides informa-
`tion about the user’s heart rate and wherein the output data
`from the motion detecting sensor provides information about
`the user’s periodic physical movementsother than heartbeats;
`(b) determining a periodic componentofthe output data from
`the motion detecting sensor; (c) filtering the output data from
`the heartbeat waveform sensor to remove variations that are
`
`slow with respect to an expected heart rate, whereinthefil-
`tering produceshigh pass filtered output data from the heart-
`beat waveform sensor; (d) determining the user’s heart rate;
`and (e) presenting the user’s heart rate. In various implemen-
`tations, the methods include using the periodic component of
`the output data from the motion detecting sensor to remove a
`corresponding periodic componentfrom the highpass filtered
`output data from the heartbeat waveform sensor. The filtering
`
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`may removea frequencyless than about 0.6 Hz(or less than
`about 0.3 Hz) from the output data from the heartbeat wave-
`form sensor.
`
`Insome implementations, the motion detecting sen-
`[0020]
`sor is an accelerometer or a gyroscope. The heartbeat wave-
`form sensor may be a photoplethysmography sensor or an
`ECGsensor.
`
`In certain embodiments, methods include an addi-
`[0021]
`tional operation of determining the expected heart rate, and
`from the expectedheart rate, setting a high pass frequency for
`the filtering.
`[0022]
`In some cases, determining the expected heart rate
`includes analyzing the output data from the motion detecting
`sensor, which may involve inferring a useractivity level and/
`or detecting an intensity of user activity or a type of user
`activity. As an example, detecting the type of user activity
`maybe detecting running, walking, standing, sitting, or lying
`down. As a further example, detecting the intensity of user
`activity may be detecting running or walking.
`[0023]
`In somecases, the periodic movement detected by
`the motion sensoris a wearer’s limb movements, which may
`be, e.g., steps, swim strokes, ankle revolutions while bicy-
`cling, and leg movements on cardio machines.
`[0024]
`In some method implementations, the operation of
`collecting the output data from the heartbeat waveform sensor
`includesthe following operations: (1) pulsing a light source in
`the worn biometric monitoring device ata first frequency; and
`(i1) detecting light from the light sourceat the first frequency.
`Pulsing the light source at the first frequency may involve
`emitting a succession oflight pulses of substantially constant
`intensity.
`Incertain embodiments, presenting the user’s heart
`[0025]
`rate includes presenting the heart rate on the worn biometric
`monitoring device. In certain embodiments, presenting the
`user’s heart rate includes presenting the heart rate on an
`external device that periodically communicates with the worn
`biometric monitoring device.
`[0026]
`In some implementations, a method additional
`includesthe operation for determining the user’s resting heart
`rate, and in such cases, the filtering removes a frequencyless
`than about the frequency of the user’s heart rate. In some
`cases, determining the user’s resting heart rate involves mea-
`suring the user’s heart rate soon after they wake up and are
`whilestill stationary in bed. In somecases, determining the
`user’s resting heart rate involves measuring the user’s average
`heart rate ofthe user while the useris sleeping. In somecases,
`determining the user’s resting heart rate involves making
`multiple measurements of the user’s heart rate when the user
`is awake andstationary.
`[0027] Another aspect ofthe invention pertains to wearable
`fitness monitoring devices designed or configured to pre-
`process heartbeat waveform signals when determining a
`user’s heart rate. The wearable fitness monitoring devices
`may be characterized by the following features: a motion
`sensor configured to provide output corresponding to motion
`by a user wearing the fitness monitoring device; a heartbeat
`waveform sensor; and control logic containing instructions
`for: (a) collecting concurrent output data from the heartbeat
`waveform sensor and output data from the motion detecting
`sensor, wherein the output data from the heart beat waveform
`sensor provides information about the user’s heart rate and
`wherein the output data from the motion detecting sensor
`provides information about
`the user’s periodic physical
`movements other than heartbeats; (b) determining a periodic
`
`componentofthe output data from the motion detecting sen-
`sor; (c) filtering the output data from the heartbeat waveform
`sensor to removevariations that are slow with respect to an
`expected heart rate, wherein the filtering produces high pass
`filtered output data from the heartbeat waveform sensor; (d)
`determining the user’s heart rate; and (e) presenting the user’s
`heart rate.
`
`[0028] The control logic is typically, though not necessar-
`ily, located on the fitness monitoring device. It may be imple-
`mented as hardware, software, firmware, or any combination
`thereof. The data used by the control logic in executing the
`instructions described herein may be stored (e.g., buffered)
`by associated memory, registers, and the like, which may be
`entirely resident on the device or partially resident on a paired
`secondary device. Examples of suitable architectures for
`implementing the control logic are presented below with
`referenceto, e.g., FIGS. 11A-G, 12A-C, 13A-B, and 14A-D.
`[0029]
`In some devices, the motion detecting sensor is an
`accelerometer or a gyroscope. In certain embodiments, the
`device’s heartbeat waveform sensor is a photoplethysmo-
`graphic sensor having (i) a periodic light source,(11) a photo
`detector positioned to receive periodic light emitted by the
`light source after interacting with the user’s skin, and (iti)
`circuitry determining the user’s heart rate from output of the
`photo detector. In some implementations, the photoplethys-
`mographic sensor includes two periodic light sources strad-
`dling the photo detector. In some implementations, the pho-
`toplethysmographic sensor additionally includes a housing
`having a recess in which the photo detector is disposed. The
`housing of the photoplethysmographic sensor may have a
`second recess in which the periodic light source is disposed.
`In some designs, the housing protrudes at least about 1 mm
`above a base surface of the wearable fitness monitoring
`device arranged to press against the user’s skin when worn.
`Further,
`the photoplethysmographic sensor further may
`include a spring configured to resist compression when the
`protruding housing presses against the user’s skin. In certain
`embodiments,
`the photoplethysmographic
`sensor
`also
`includes an IMLfilm overthe photo detector and the periodic
`light source. In certain embodiments,
`the periodic light
`source is an LED.
`
`In certain embodiments, the control logic includes
`[0030]
`instructions for using the periodic componentof the output
`data from the motion detecting sensor to remove a corre-
`sponding periodic component from the high pass filtered
`output data from the heartbeat waveform sensor. In certain
`embodiments, the instructions for filtering include instruc-
`tions for removing a frequencyless than about 0.6 Hz (or less
`than about 0.3 Hz) from the output data from the heartbeat
`waveform sensor.
`
`In certain embodiments, the control logic addition-
`[0031]
`ally includes instructions for determining the expected heart
`rate, and from the expected heart rate, setting a high pass
`frequencyfor the filtering.
`[0032]
`In some cases, the instructions for determining the
`expected heart rate include instructions for analyzing the
`output data from the motion detecting sensor. Further, the
`instructions for analyzing the output data from the motion
`detecting sensor may includeinstructionsfor inferring a user
`activity level. Additionally, the instructions for analyzing the
`output data from the motion detection sensor may include
`instructions for detecting an intensity ofuseractivity or a type
`of user activity. In somecases, the instructions for detecting
`the type of user activity include instructions for detecting
`
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`US 2014/0275854 Al
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`Sep. 18, 2014
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`running, walking, standing, sitting, or lying down. In some
`cases, the instructions for detecting the intensity ofuseractiv-
`ity include instructions for detecting running or walking. In
`some implementations, the periodic movementto be detected
`by the motion sensor is a wearer’s limb movements.
`[0033]
`In some implementations, the instructions for col-
`lecting the output data from the heartbeat wavefor