Cross-cut: `bracelet`

Axis: form_factor

17 corpus entries disclose this tag.

Earliest disclosure: 1937-09

Listed in chronological order. Each entry’s prior_art_notes and disclosure_citation constitute the citeable prior art material.

The Lens (Lensman series) — wrist-worn device with single-wearer biometric attunement (1937-09)

id: doc-smith-lens
corpus: fictional
form factor: bracelet
creator: E.E. ‘Doc’ Smith
disclosure: Smith, E.E. ‘Doc’. Galactic Patrol, serialized in Astounding Stories beginning September 1937 (book edition 1950); ‘the Lens’ — a crystalline device worn at the wrist that is attuned to exactly one bearer, confers telepathic communication and translation, cannot be used by anyone else, and is harmful to an unauthorized wearer.
ip status: fictional
prior art notes: Discloses a wrist-worn device that is biometrically attuned to a single authorized wearer, refuses to function for (and harms) any other wearer, and provides communication/translation services. Relevant to wearable-security claims combining ‘a wrist-worn device’, ‘binding to a single enrolled wearer by a biometric or physiological signature’, and ‘disabling/refusal on an unrecognized wearer’ (the now-common ‘wrist-off detection’ / ‘continuous wearer authentication’ feature). § 103 motivation that wrist-worn single-wearer attunement was an articulated objective by 1937. Cf. [[batman-utility-belt]] (a storage belt) — distinct: this is a wearer-attuned device.
Wonder Woman’s bracelets (Bracelets of Submission) (1941-12) — wonder-woman-bracelets [fictional] — All Star Comics #8 (cover date December 1941, published October 1941), DC Comics; first appearance of Wonder Woman and her wrist-worn bracelets.
Cole & Kripke et al. (1992) — automatic sleep/wake identification from wrist activity (the Cole-Kripke algorithm) (1992)
id: cole-kripke-1992-wrist-actigraphy-sleep
corpus: academic
form factor: watch
creator: Roger J. Cole / Daniel F. Kripke et al.
disclosure: Cole RJ, Kripke DF, Gruen W, Mullaney DJ, Gillin JC. ‘Automatic sleep/wake identification from wrist activity.’ Sleep 1992;15(5):461-469.
ip status: public-domain
sensors: sensor-accelerometer
algorithms: algo-sleep-staging, algo-activity-classification
prior art notes: Discloses an algorithm that classifies each epoch as sleep or wake from a wrist-worn activity (accelerometer) recording, validated against polysomnography — i.e. wrist actigraphy as a wearable sleep monitor. Any consumer-wearable claim reciting ‘estimating sleep/wake state from a wrist-worn accelerometer signal’ (the method underlying Fitbit/Jawbone-class sleep tracking) reads on Cole-Kripke 1992. Anchor for the accelerometry sleep-staging cross-cut; combined with the wrist form factor it makes wristworn sleep tracking obvious under [[obviousness-template]].

Sadeh et al. (1994) — activity-based sleep-wake identification (the Sadeh algorithm) (1994)

id: sadeh-1994-actigraphy-sleep-wake-algorithm
corpus: academic
form factor: watch
creator: Avi Sadeh / Katherine M. Sharkey / Mary A. Carskadon
disclosure: Sadeh A, Sharkey KM, Carskadon MA. ‘Activity-based sleep-wake identification: an empirical test of methodological issues.’ Sleep 1994;17(3):201-207.
ip status: public-domain
sensors: sensor-accelerometer
algorithms: algo-sleep-staging, algo-activity-classification
prior art notes: A second widely-used wrist-actigraphy sleep/wake scoring algorithm, with explicit treatment of the methodological choices (epoch length, scoring window, scaling). Prior art alongside [[cole-kripke-1992-wrist-actigraphy-sleep]] for any wearable claim reciting an actigraphy-based sleep-detection method or its parameters; both were published and validated by 1994.

Ancoli-Israel et al. (2003) — ‘The role of actigraphy in the study of sleep and circadian rhythms’ (2003-05)

id: ancoli-israel-2003-actigraphy-review
corpus: academic
form factor: watch
creator: Sonia Ancoli-Israel et al. (American Academy of Sleep Medicine review)
disclosure: Ancoli-Israel S, Cole R, Alessi C, Chambers M, Moorcroft W, Pollak CP. ‘The role of actigraphy in the study of sleep and circadian rhythms.’ Sleep 2003;26(3):342-392.
ip status: public-domain
sensors: sensor-accelerometer
algorithms: algo-sleep-staging
prior art notes: Authoritative review establishing wrist actigraphy — a wrist-worn accelerometer/activity recorder analyzed by validated algorithms — as an accepted method for estimating sleep parameters and circadian rhythm. Prior art for the proposition that a wrist-worn motion sensor with appropriate scoring yields clinically meaningful sleep metrics; the field, methods, and validation were settled and reviewed by 2003.

Fitbit Tracker (2009) — clip-on accelerometer activity and sleep monitor (2009-10)

id: fitbit-tracker-2009
corpus: private
form factor: pendant
creator: Fitbit, Inc. (James Park, Eric Friedman)
disclosure: Fitbit, Inc. ‘Fitbit Tracker’, launched October 2009 — a clip-worn device with a 3-axis accelerometer estimating steps, distance, calories burned, active minutes, and sleep quality, syncing wirelessly to a web dashboard. (The wrist PPG heart-rate variant, Fitbit Charge HR, followed in January 2015.)
ip status: patented
sensors: sensor-accelerometer
algorithms: algo-step-count, algo-calorie-estimation, algo-activity-classification, algo-sleep-staging
prior art notes: Discloses a small body-worn (clip) device with a 3-axis accelerometer that estimates step count, distance, calories, active minutes, and sleep quality on-device and syncs wirelessly to a cloud dashboard. Anticipates consumer-activity-tracker claims combining ‘a body-worn accelerometer’, ‘on-device estimation of steps/calories/activity/sleep’, and ‘wireless sync to a remote service’ from 2009. Anchor for the step-count and consumer-sleep-tracking cross-cuts on the product side.

Pantelopoulos & Bourbakis (2010) — survey on wearable sensor-based systems for health monitoring and prognosis (2010-01)

id: pantelopoulos-bourbakis-2010-wearable-health-survey
corpus: academic
form factor: other
creator: Alexandros Pantelopoulos / Nikolaos G. Bourbakis
disclosure: Pantelopoulos A, Bourbakis NG. ‘A survey on wearable sensor-based systems for health monitoring and prognosis.’ IEEE Transactions on Systems, Man, and Cybernetics, Part C (Applications and Reviews) 2010;40(1):1-12.
ip status: public-domain
sensors: sensor-ecg, sensor-ppg, sensor-spo2, sensor-accelerometer, sensor-skin-temperature, sensor-respiration-impedance
algorithms: algo-hr, algo-arrhythmia-classification, algo-spo2-estimation, algo-fall-detection, algo-activity-classification
prior art notes: Surveys, as of 2010, the architecture and components of wearable health-monitoring systems — sensors (ECG, PPG, SpO2, accelerometry, temperature, respiration), garment- and patch- and watch-based form factors, on-body processing, wireless body-area networking, and the analytics (arrhythmia, fall, activity, deterioration prediction). Prior art establishing that the general ‘multi-sensor wearable + body-area network + cloud analytics’ system architecture and its building blocks were collected and published by 2010 — useful against later claims to the bare system architecture. General anchor.

The Circle — ‘SeeChange’ wearable cameras and employee health wristbands (2013-10-08)

id: the-circle-seechange-and-health-wristbands
corpus: fictional
form factor: bracelet
creator: Dave Eggers
disclosure: Eggers, Dave. The Circle. Alfred A. Knopf, 2013 (film adaptation 2017); ‘SeeChange’ miniature wearable/mountable cameras streaming continuously, and employee wristbands (worn in pairs on each wrist) that continuously monitor heart rate, activity, sleep, and other physiological data and upload it to the company.
ip status: fictional
sensors: sensor-ppg, sensor-accelerometer, sensor-camera-rgb
algorithms: algo-hr, algo-step-count, algo-sleep-staging
prior art notes: Discloses (a) continuously-worn wristbands with PPG and motion sensing that stream heart rate, activity, and sleep data to an employer, and (b) tiny body-wearable always-streaming cameras. Relevant to workplace-wellness wearable claims combining ‘a wrist-worn PPG/motion sensor’, ‘continuous physiological streaming to a remote/employer system’, and to body-worn-camera streaming claims. § 103 motivation that the employer-monitored wrist wearable and the always-streaming wearable camera were articulated objectives by 2013.

Microsoft Band (2014) — ten-sensor wristband (optical HR, GPS, GSR, UV, skin temp, barometer, ambient light, capacitive, microphone, IMU) (2014-10-30)

id: microsoft-band-2014
corpus: private
form factor: watch
creator: Microsoft Corp.
disclosure: Microsoft Corp. ‘Microsoft Band’, released 30 October 2014 — a wristband integrating ten sensors: an optical (PPG) heart-rate sensor, a 3-axis accelerometer/gyroscope, GPS, an ambient-light sensor, a skin-temperature sensor, a UV sensor, a capacitive (wear-detection) sensor, a galvanic-skin-response sensor, a microphone, and a barometer (added in Band 2).
ip status: patented
sensors: sensor-ppg, sensor-accelerometer, sensor-gyroscope, sensor-skin-temperature, sensor-uv, sensor-gsr, sensor-barometer, sensor-photodiode-ambient, sensor-microphone-air
algorithms: algo-hr, algo-step-count, algo-calorie-estimation, algo-sleep-staging, algo-stress-index, algo-uv-dose-tracking
prior art notes: Discloses a single wristband integrating an unusually broad sensor suite — reflectance-PPG HR, IMU, GPS, skin temperature, UV exposure, galvanic skin response (electrodermal activity), barometer, ambient light, capacitive wear-detection, and a microphone — feeding HR, activity, sleep, UV dose, and stress-index estimations. Prior art for multi-sensor-wristband claims reciting combinations of these sensors (notably wrist GSR/EDA + PPG + skin temperature for stress) from October 2014. Product-side anchor for the multi-sensor wristband cross-cut.

WHOOP Strap (2015) — display-less wrist/bicep PPG band for continuous HR/HRV, sleep and recovery (2015)

id: whoop-strap-2015
corpus: private
form factor: bracelet
creator: WHOOP, Inc. (Will Ahmed)
disclosure: WHOOP, Inc. ‘WHOOP Strap’, launched 2015 — a screenless band worn on the wrist or upper arm with photoplethysmography, a 3-axis accelerometer, and skin-temperature sensing, providing continuous heart rate, heart-rate variability, respiratory rate, sleep staging, and a derived ‘recovery’ score, with no on-device display.
ip status: patented
sensors: sensor-ppg, sensor-accelerometer, sensor-skin-temperature
algorithms: algo-hr, algo-hrv, algo-respiratory-rate, algo-sleep-staging, algo-activity-classification
prior art notes: Discloses a display-less band worn on the wrist or upper arm with PPG, accelerometry, and skin-temperature sensing that continuously derives HR, HRV, respiratory rate, and sleep stages and combines them into a daily ‘recovery’ index, with no screen (companion-app readout). Anticipates screenless-band claims and PPG-derived-HRV/recovery-score claims from 2015. Product-side anchor for the bracelet × PPG cross-cut and the HRV cross-cut.

Fitbit Charge HR (2015) — wristband with continuous wrist-PPG heart rate (‘PurePulse’) (2015-01-06)

id: fitbit-charge-hr-2015
corpus: private
form factor: watch
creator: Fitbit, Inc.
disclosure: Fitbit, Inc. ‘Fitbit Charge HR’, announced January 2015 — a wristband with ‘PurePulse’ continuous optical (green-LED PPG) heart rate, a 3-axis accelerometer, steps/distance/floors/calories/active-minutes, automatic sleep tracking, and call/text notifications.
ip status: patented
sensors: sensor-ppg, sensor-accelerometer, sensor-barometer
algorithms: algo-hr, algo-step-count, algo-calorie-estimation, algo-activity-classification, algo-sleep-staging
prior art notes: Discloses a wristband with continuous green-LED reflectance-PPG heart rate plus accelerometry and an altimeter, deriving HR, steps, floors, calories, and sleep, with phone notifications. A mainstream realization of [[mendelson-ochs-1988-reflectance-pulse-oximetry]]-geometry wrist PPG; anticipates wrist-PPG-HR-band claims from January 2015. Product-side anchor for the watch × PPG cross-cut alongside [[apple-watch-original-2015]].

Mukkamala et al. (2015) — ‘Toward Ubiquitous Blood Pressure Monitoring via Pulse Transit Time: Theory and Practice’ (2015-08)

id: mukkamala-2015-ptt-cuffless-bp-review
corpus: academic
form factor: other
creator: Ramakrishna Mukkamala et al.
disclosure: Mukkamala R, Hahn J-O, Inan OT, Mestha LK, Kim C-S, Töreyin H, Kyal S. ‘Toward Ubiquitous Blood Pressure Monitoring via Pulse Transit Time: Theory and Practice.’ IEEE Transactions on Biomedical Engineering 2015;62(8):1879-1901.
ip status: public-domain
sensors: sensor-ecg, sensor-ppg, sensor-cuffless-bp-ptt, sensor-cuffless-bp-tonometry
algorithms: algo-pwv-bp-estimation
prior art notes: Canonical 2015 review of cuffless blood-pressure estimation by pulse transit time / pulse arrival time / pulse wave velocity: the physiological models, the practical sensor configurations (ECG+PPG, dual PPG, ballistocardiogram+PPG), the calibration strategies, and the accuracy limitations. Prior art for cuffless-BP wearable claims reciting any of the configurations or calibration approaches surveyed here — they were collected, modeled, and published by 2015. Combined with watch/ring/patch form-factor disclosures, makes wearable PTT-based BP an obvious combination under [[obviousness-template]].

Gao et al. (Javey group) (2016) — fully integrated wearable sensor array for multiplexed in-situ perspiration analysis (2016-01-28)

id: gao-javey-2016-wearable-sweat-sensor-array
corpus: academic
form factor: headband
creator: Wei Gao et al. / Ali Javey group (UC Berkeley)
disclosure: Gao W, Emaminejad S, Nyein HYY, Challa S, Chen K, Peck A, et al. (Javey A). ‘Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis.’ Nature 2016;529(7587):509-514.
ip status: public-domain
sensors: sensor-lactate, sensor-glucose-cgm, sensor-electrolyte, sensor-ph, sensor-skin-temperature, sensor-microfluidic-sweat-collection
algorithms: algo-electrolyte-trend, algo-hydration-status
prior art notes: Discloses a fully integrated wearable (wristband / headband) with an array of electrochemical sensors measuring multiple sweat analytes simultaneously (glucose, lactate, Na+, K+) plus skin temperature for real-time signal compensation, with on-board signal conditioning, microcontroller, and wireless transmission to a phone — i.e. a complete in-situ sweat biochemistry monitor. Any wearable claim reciting ‘a band-form device with an array of two or more electrochemical sweat-analyte sensors plus a temperature sensor for compensation, with integrated electronics and wireless output’ reads on Gao/Javey 2016. Anchor for the sweat-electrochemical-sensing cross-cuts on the real side; [[bandodkar-wang-2014-wearable-electrochemical-sensors-review]] is the contemporaneous review.

FDA 510(k) K181861 (2018) — Empatica Embrace physiological-signal-based seizure monitoring system (2018)

id: fda-k181861-empatica-embrace-seizure-system-2018
corpus: regulatory
form factor: watch
creator: U.S. Food and Drug Administration (CDRH); submitter Empatica Inc.
disclosure: U.S. FDA, 510(k) Premarket Notification K181861 (Empatica Inc., ‘Embrace’ physiological-signal-based seizure monitoring system) — a wrist-worn device using accelerometry plus electrodermal activity to detect probable generalized tonic-clonic seizures and alert caregivers; reported as the first FDA-cleared smartwatch indicated for use in neurology (clearance announced February 2018). (Verify which Embrace generation K181861 maps to; the original clearance may carry a different K-number.)
ip status: regulatory-filing
sensors: sensor-accelerometer, sensor-gsr
algorithms: algo-seizure-detection
prior art notes: A public, dated FDA record of a wrist-worn device detecting probable generalized tonic-clonic seizures from combined accelerometry and electrodermal activity, with caregiver alerting — the non-EEG route to wearable seizure detection. Establishes the public availability of that device as of 2018; the 510(k) cites a predicate chain that is itself prior art. Prior art for wrist-based seizure-detection claims using motion + EDA; regulatory anchor pairing with [[empatica-embrace2-seizure-watch-2018]] (the EEG route is anchored separately by [[zanetti-aminifar-atienza-eglass-2025]] and [[chb-mit-scalp-eeg-database-2009]]).

Empatica Embrace2 (2018) — first FDA-cleared seizure-monitoring smartwatch (accelerometer + electrodermal activity) (2018-01-31)

id: empatica-embrace2-seizure-watch-2018
corpus: private
form factor: watch
creator: Empatica Inc. (Rosalind Picard, Matteo Lai, et al.)
disclosure: Empatica Inc. ‘Embrace2’ smartwatch, FDA-cleared January 2018 — a wrist-worn device with a 3-axis accelerometer/gyroscope, an electrodermal-activity (EDA) sensor, and a peripheral skin-temperature sensor, running an on-device classifier that detects probable generalized tonic-clonic seizures from the combined motion + EDA signature and alerts caregivers; the first FDA-cleared smartwatch for seizure monitoring. (Descends from the MIT Media Lab ‘iCalm’/’Q sensor’ EDA wristband research, Picard et al.)
ip status: patented
sensors: sensor-accelerometer, sensor-gyroscope, sensor-gsr, sensor-skin-temperature
algorithms: algo-seizure-detection, algo-stress-index, algo-activity-classification
prior art notes: Discloses a wristworn device that detects probable generalized tonic-clonic seizures by combining a motion (accelerometer/gyroscope) signature with an electrodermal-activity (sympathetic-surge) signature in an on-device classifier, and alerts caregivers — i.e. multimodal wrist-based seizure detection, distinct from the EEG-based approach. Anticipates wrist-seizure-detection claims combining ‘a wrist-worn accelerometer and an electrodermal-activity sensor’ and ‘a classifier flagging a seizure from their combined signal’ from 2018. Product-side anchor for the wrist × seizure-detection cross-cut; complementary to the EEG route in [[zanetti-aminifar-atienza-eglass-2025]] and [[chb-mit-scalp-eeg-database-2009]].

Black Panther ‘Kimoyo beads’ (2018-02-16)

id: black-panther-kimoyo-beads
corpus: fictional
form factor: bracelet
creator: Marvel Studios
disclosure: Black Panther (Marvel Studios), released February 16, 2018; the wrist-worn ‘Kimoyo beads’ — bracelet beads providing voice/holographic communication, holographic information display, remote vehicle/device control, and on-body medical diagnostics and treatment.
ip status: fictional
prior art notes: Discloses a wrist-worn bracelet of modular beads functioning as (a) a voice/visual communicator, (b) a projected holographic display surface, (c) a remote controller for paired vehicles and devices, and (d) an on-body medical scanner reporting injury and physiological state. Relevant to bracelet/wristband claims combining ‘a band of modular elements’, ‘a display’, ‘a wireless transceiver for device control’, and ‘sensors for physiological measurement’. § 103 motivation that the multifunction medical/communication wrist bracelet was an articulated objective by 2018.

Aktiia bracelet (2021) — optical-PPG-based continuous cuffless blood-pressure monitoring bracelet (2021-01)

id: aktiia-bracelet-cuffless-bp-2021
corpus: private
form factor: bracelet
creator: Aktiia SA
disclosure: Aktiia SA. ‘Aktiia bracelet’ (later ‘Hilo’), CE-marked and launched in Europe January 2021 — a slim wristband with optical photoplethysmography that, after a one-time initialization against a conventional cuff (and periodic re-calibration), estimates systolic and diastolic blood pressure several times a day automatically, day and night, from the wrist PPG pulse waveform.
ip status: patented
sensors: sensor-ppg, sensor-cuffless-bp-ptt, sensor-accelerometer
algorithms: algo-pwv-bp-estimation, algo-hr
prior art notes: Discloses a slim wristband that, after a one-time cuff initialization (and periodic re-calibration), automatically estimates systolic and diastolic blood pressure multiple times per day and night purely from the wrist optical-PPG pulse waveform — i.e. continuous, fully cuffless, calibration-initialized wrist BP monitoring. Anticipates continuous-cuffless-wrist-BP claims from 2021; the PPG-pulse-feature-to-BP mapping rests on the much older PTT/PWV-BP and pulse-contour literature ([[geddes-1981-pulse-transit-time-bp]], [[mukkamala-2015-ptt-cuffless-bp-review]]). Product-side anchor for the bracelet × cuffless-BP cross-cut.

Cross-cut: bracelet