Cross-cut: `algo-sleep-staging`

Axis: algorithms

21 corpus entries disclose this tag.

Earliest disclosure: 1953-09-04

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

Aserinsky & Kleitman (1953) — discovery of REM sleep via electrooculography (1953-09-04)

id: aserinsky-kleitman-1953-rem-sleep
corpus: academic
form factor: other
creator: Eugene Aserinsky / Nathaniel Kleitman (University of Chicago)
disclosure: Aserinsky E, Kleitman N. ‘Regularly occurring periods of eye motility, and concomitant phenomena, during sleep.’ Science 1953;118(3062):273-274.
ip status: public-domain
sensors: sensor-eog, sensor-eeg
algorithms: algo-sleep-staging
prior art notes: Establishes that sleep is not homogeneous — that there are recurring periods of rapid eye movement detectable by electrooculography (with concomitant EEG changes) — i.e. the existence of distinguishable sleep states detectable from ocular/cortical electrophysiology. Foundational prior art for any sleep-staging wearable: the premise that sleep states are detectable from EOG/EEG signals is public since 1953. Anchor for the sleep-staging cross-cut.

Rechtschaffen & Kales (1968) — standardized sleep-stage scoring manual (1968)

id: rechtschaffen-kales-1968-sleep-scoring-manual
corpus: standards
form factor: other
creator: Allan Rechtschaffen / Anthony Kales (eds), for the UCLA Brain Information Service
disclosure: Rechtschaffen A, Kales A (eds). ‘A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects.’ Public Health Service / U.S. Government Printing Office / UCLA Brain Information Service, NIH Publication No. 204, 1968.
ip status: standards
sensors: sensor-eeg, sensor-eog, sensor-emg
algorithms: algo-sleep-staging
prior art notes: Standardizes the definition of sleep stages and the rules for scoring them from EEG + EOG + EMG (polysomnography). Any wearable claim reciting ‘classifying sleep into stages from electrophysiological/physiological signals’ rests on the staging framework standardized here. Combined with [[muse-headband-2014]]-type form-factor disclosures, makes wearable automated sleep-staging an obvious combination under [[obviousness-template]].

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.

Looney et al. (2012) — ‘The in-the-ear recording concept’ (ear-EEG) (2012-11)

id: looney-mandic-2012-in-ear-eeg
corpus: academic
form factor: earbud
creator: David Looney / Preben Kidmose / Danilo P. Mandic et al.
disclosure: Looney D, Kidmose P, Park C, Ungstrup M, Rank ML, Rosenkranz K, Mandic DP. ‘The in-the-ear recording concept: user-centered and wearable brain monitoring.’ IEEE Pulse 2012;3(6):32-42. (See also Kidmose P, et al. ‘A study of evoked potentials from ear-EEG.’ IEEE Trans Biomed Eng 2013;60(10):2824-2830.)
ip status: public-domain
sensors: sensor-dry-eeg-electrode, sensor-eeg
algorithms: algo-drowsiness-detection, algo-sleep-staging, algo-bci-ssvep, algo-erp-classification
prior art notes: Discloses recording EEG from electrodes placed inside the ear canal / concha of an individually-fitted earpiece — i.e. EEG in an earbud / hearing-aid form factor, demonstrated to capture alpha modulation, auditory steady-state and evoked responses. Any wearable claim reciting ‘EEG electrodes disposed on an in-ear earpiece to measure an electroencephalographic signal of the wearer’ reads on Looney et al. 2012. Anchor for the earbud/hearing-aid × EEG cross-cut; complementary to [[debener-2015-ceegrid-around-ear-eeg]] and [[zanetti-aminifar-atienza-eglass-2025]] (around-ear / temporal pickup).

Hexoskin smart shirt (2014) — textile-integrated ECG, respiration and activity garment (2013)

id: hexoskin-smart-shirt-2014
corpus: private
form factor: garment
creator: Carre Technologies Inc.
disclosure: Carre Technologies Inc. (Hexoskin). ‘Hexoskin Smart Shirt’, introduced 2013 (consumer); a compression shirt with knitted dry textile electrodes for single-lead ECG, two-channel respiratory inductive plethysmography (thoracic + abdominal expansion), a 3-axis accelerometer, and a removable electronics pod, deriving HR, HRV, breathing rate/volume, cadence, steps, and sleep. (Used in NASA/CSA ‘Astroskin’ studies.)
ip status: patented
sensors: sensor-ecg, sensor-respiration-impedance, sensor-piezoelectric, sensor-accelerometer
algorithms: algo-hr, algo-hrv, algo-respiratory-rate, algo-activity-classification, algo-sleep-staging
prior art notes: Discloses a consumer/research compression shirt with textile-integrated dry ECG electrodes, two-channel respiratory inductive plethysmography (thoracic + abdominal), an accelerometer, and a removable electronics pod, deriving HR, HRV, breathing rate and volume, activity, and sleep. A commercial realization of [[paradiso-2005-wealthy-knitted-smart-shirt]]; anticipates smart-shirt claims combining ‘textile-integrated ECG and respiration sensors’ and ‘a detachable electronics module’ from 2013. Product-side anchor for the garment × textile-electrode cross-cut.

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.

Muse headband (InteraXon, 2014) — multi-channel dry-electrode EEG headband for meditation and sleep (2014-05)

id: muse-headband-2014
corpus: private
form factor: headband
creator: InteraXon Inc.
disclosure: InteraXon Inc. ‘Muse’ brain-sensing headband, shipped 2014 — a forehead-band EEG device with frontal (AF7/AF8/Fp1/Fp2-region) and behind-the-ear (TP9/TP10) dry/conductive-rubber electrodes, giving real-time neurofeedback for meditation (and, in ‘Muse S’, sleep tracking).
ip status: patented
sensors: sensor-dry-eeg-electrode, sensor-eeg
algorithms: algo-attention-state, algo-cognitive-workload, algo-sleep-staging
prior art notes: Discloses a forehead-band wearable EEG device with frontal and behind-the-ear (TP9/TP10) dry electrodes providing real-time neurofeedback for meditation training and (later) sleep staging. Anticipates EEG-headband claims combining ‘a forehead band’, ‘frontal and mastoid/behind-ear dry electrodes’, and ‘real-time feedback on a meditation or sleep state’ from 2014. Note: its TP9/TP10 around-ear pickup is the same general region used by [[zanetti-aminifar-atienza-eglass-2025]] — relevant prior art for around-ear-EEG wearable claims. Product-side anchor for the headband × EEG cross-cut.

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]].

Oura Ring (Gen 1, 2015) — finger-ring PPG, skin-temperature and accelerometer for HRV, sleep and body temperature (2015-08)

id: oura-ring-gen1-2015
corpus: private
form factor: ring
creator: Oura Health Oy
disclosure: Oura Health Oy. ‘Oura Ring’ (1st generation), crowdfunded 2015, shipped 2016 — a titanium finger ring with infrared photoplethysmography, an NTC skin-temperature sensor, and a 3-axis accelerometer, deriving resting heart rate, heart-rate variability, respiratory rate, sleep staging, and body-temperature trend.
ip status: patented
sensors: sensor-ppg, sensor-skin-temperature, sensor-accelerometer
algorithms: algo-hr, algo-hrv, algo-respiratory-rate, algo-sleep-staging
prior art notes: Discloses a finger-ring wearable with infrared PPG, a skin-temperature sensor, and an accelerometer, deriving resting HR, HRV, respiratory rate, sleep stages, and a body-temperature trend, with companion-app readout. A commercial realization, ~12-16 years later, of the MIT ring-sensor concept ([[asada-mit-wearable-ring-sensor-2003]]); to the extent later claims recite ring-form PPG + skin-temperature + HRV/sleep, both Asada 2003 and Oura 2015 are prior art. Product-side anchor for the ring × PPG × HRV and ring × skin-temperature cross-cuts.

Debener et al. (2015) — cEEGrid: unobtrusive around-the-ear EEG with flexible printed electrodes (2015-11-17)

id: debener-2015-ceegrid-around-ear-eeg
corpus: academic
form factor: patch
creator: Stefan Debener / Martin G. Bleichner et al. (Oldenburg)
disclosure: Debener S, Emkes R, De Vos M, Bleichner MG. ‘Unobtrusive ambulatory EEG using a smartphone and flexible printed electrodes around the ear.’ Scientific Reports 2015;5:16743.
ip status: public-domain
sensors: sensor-dry-eeg-electrode, sensor-eeg
algorithms: algo-erp-classification, algo-sleep-staging, algo-drowsiness-detection
prior art notes: Discloses a flexible, printed, C-shaped electrode array worn around the ear (behind and below the auricle) for unobtrusive ambulatory EEG, recorded to a smartphone-class device. Any wearable claim reciting ‘an array of EEG electrodes arranged around/behind the ear of the wearer’ (the geometry used by EEG glasses, EEG earbuds, and EEG behind-the-ear stickers) reads on Debener et al. 2015. Directly relevant prior art for [[zanetti-aminifar-atienza-eglass-2025]] (which uses temporal/around-ear pickup) and for around-ear-EEG hearable claims; anchor for that cross-cut.

Omron HeartGuide (2019) — wristwatch with an inflatable oscillometric blood-pressure cuff in the band (2019-01-08)

id: omron-heartguide-2019
corpus: private
form factor: watch
creator: Omron Healthcare Co., Ltd.
disclosure: Omron Healthcare. ‘HeartGuide’ (model BP8000-M), announced January 2019, FDA-cleared — a wristwatch whose band contains an inflatable cuff and an oscillometric pressure transducer, taking a clinically-validated brachial-style blood-pressure measurement at the wrist on demand, alongside heart rate, steps, and sleep.
ip status: patented
sensors: sensor-pressure-skin, sensor-accelerometer, sensor-ppg
algorithms: algo-hr, algo-step-count, algo-sleep-staging
prior art notes: Discloses a wristwatch whose strap incorporates an inflatable cuff and pressure transducer, performing an oscillometric blood-pressure measurement at the wrist (occlude-and-release, automatically positioned at heart level by the wearer) in a watch form factor, plus activity and sleep tracking. Distinct from cuffless-PPG approaches: it is a true oscillometric cuff miniaturized into a watch band. Anticipates watch-with-integrated-inflatable-cuff BP claims from 2019. Product-side anchor for the watch × oscillometric-BP cross-cut (vs. the cuffless-PPG variant in [[samsung-galaxy-watch-bp-ecg-2020]] and [[aktiia-bracelet-cuffless-bp-2021]]).

BioIntelliSense BioSticker (2019) — long-wear adhesive chest patch with extensive multi-parameter monitoring (2019-12)

id: biointellisense-biosticker-2019
corpus: private
form factor: patch
creator: BioIntelliSense, Inc.
disclosure: BioIntelliSense, Inc. ‘BioSticker’ single-use adhesive medical-grade biosensor, FDA-cleared 2019 — a chest patch with up to 30-day wear continuously measuring skin temperature, single-lead ECG-derived heart rate at rest, respiratory rate at rest, body position, activity (steps, cadence, gait), sleep, cough, vomiting events, and falls, with wireless upload.
ip status: patented
sensors: sensor-ecg, sensor-accelerometer, sensor-skin-temperature, sensor-microphone-air
algorithms: algo-hr, algo-respiratory-rate, algo-activity-classification, algo-posture-detection, algo-fall-detection, algo-cough-detection, algo-gait-analysis, algo-sleep-staging
prior art notes: Discloses a single-use 30-day adhesive chest patch combining skin temperature, resting HR-from-ECG, resting RR, posture/activity, sleep, cough and vomiting event detection, and falls — i.e. an unusually broad multi-parameter long-wear patch with explicit event-detection (cough, vomit) classifiers. Anticipates long-wear multi-parameter patch claims from 2019, including the event-detection (cough/vomit) elements that some later patents recite. Product-side anchor for the patch × long-wear multi-parameter cross-cut.

Withings ScanWatch (2020) — hybrid analog watch with PPG, SpO2 pulse oximetry, single-lead ECG, and accelerometer (2020-01-05)

id: withings-scanwatch-2020
corpus: private
form factor: watch
creator: Withings SA
disclosure: Withings (Nokia/Withings). ‘ScanWatch’, announced January 2020 (CE-marked 2020; FDA cleared 2022) — a hybrid analog wristwatch integrating a reflectance-PPG sensor (heart rate, irregular-rhythm screening), an SpO2 (pulse-oximetry) measurement, a single-lead ECG (back electrode plus a bezel electrode touched by the opposite hand, with AF detection), a 3-axis accelerometer, and an altimeter — with sleep and activity tracking.
ip status: patented
sensors: sensor-ppg, sensor-spo2, sensor-ecg, sensor-accelerometer, sensor-barometer
algorithms: algo-hr, algo-spo2-estimation, algo-afib-detection, algo-arrhythmia-classification, algo-sleep-staging, algo-step-count, algo-respiratory-rate
prior art notes: Discloses a wristwatch combining reflectance-PPG heart rate, pulse-oximetry SpO2, a single-lead ECG with AF detection, accelerometry, and an altimeter, with sleep-apnea screening (from the SpO2/respiration signals) — multiple regulated cardiorespiratory measurements in one consumer watch. Anticipates multi-modal medical-smartwatch claims reciting combinations of wrist PPG-HR + wrist SpO2 + single-lead ECG from 2020. Product-side anchor for the watch × {PPG, SpO2, ECG} multi-sensor cross-cut.

Ultrahuman Ring AIR (2023) — smart ring with metabolic-focus tracking (PPG, skin temperature, IMU) (2023)

id: ultrahuman-ring-air-2023
corpus: private
form factor: ring
creator: Ultrahuman Healthcare Pvt. Ltd.
disclosure: Ultrahuman Healthcare Pvt. Ltd. ‘Ultrahuman Ring AIR’, launched 2023 — a titanium smart ring with infrared photoplethysmography, IR skin-temperature, and a 6-axis IMU, deriving HR, HRV, skin temperature, sleep staging, activity, and metabolic-health framing (paired with the company’s CGM-based metabolism platform).
ip status: patented
sensors: sensor-ppg, sensor-skin-temperature, sensor-accelerometer, sensor-gyroscope
algorithms: algo-hr, algo-hrv, algo-sleep-staging, algo-respiratory-rate
prior art notes: Discloses a smart ring with IR PPG, skin-temperature, and a 6-axis IMU, deriving HR/HRV, sleep, and activity, packaged with a metabolic-health platform (CGM-linked). Product-side reference in the ring × PPG cross-cut alongside [[oura-ring-gen1-2015]] and [[samsung-galaxy-ring-2024]].

HealthyPi Move (ProtoCentral, 2026) — open-source medical-grade smartwatch (2024)

id: healthypi-move-2026
corpus: open
form factor: watch
creator: ProtoCentral Electronics
disclosure: ProtoCentral Electronics (Bengaluru, India). ‘HealthyPi Move’ fully open-source AMOLED smartwatch — Crowd Supply campaign launched 2024, units shipping 15 May 2026. Sensors: single-lead ECG, dual-site PPG (wrist + finger), SpO2, blood-pressure trending, EDA/GSR, heart rate, HRV, respiration rate (derived), body temperature, 6-axis IMU. Compute: Nordic nRF5340 (dual ARM Cortex-M33). Display: AMOLED, 300 mAh battery. Companion app: Flutter, runs on Android/iOS/macOS/Windows/Linux, all data stored locally. Hardware design, firmware (Zephyr RTOS on nRF Connect SDK), and companion app all open-source. https://www.crowdsupply.com/protocentral/healthypi-move
ip status: open-permissive
sensors: sensor-ecg, sensor-ppg, sensor-spo2, sensor-multi-wavelength-ppg, sensor-gsr, sensor-accelerometer, sensor-gyroscope, sensor-skin-temperature
algorithms: algo-hr, algo-hrv, algo-spo2-estimation, algo-respiratory-rate, algo-pwv-bp-estimation, algo-sleep-staging, algo-activity-classification, algo-step-count
prior art notes: Discloses, as fully open-source hardware and firmware (CC and MIT-style licensing across components), a wrist-worn smartwatch with the full consumer-medical sensor stack: single-lead ECG between back-of-watch electrode and a finger-touch electrode; multi-wavelength reflectance PPG with SpO2 and BP-trending; EDA/GSR; skin temperature; 6-axis IMU; on-device Zephyr-RTOS application; AMOLED display; all-local data storage via cross-platform Flutter app. Anticipates wrist-multi-sensor-watch claims from 2024-2026 to the extent they recite combinations of these elements; as open prior art it is unencumbered and any patent claim reciting these combinations must distinguish over HealthyPi Move’s specific implementation. The product-side anchor for the ‘open watch with the full sensor stack’ cross-cut.

Samsung Galaxy Ring (2024) — smart ring with PPG, skin temperature and accelerometer for HR/HRV, sleep and cycle tracking (2024-07-10)

id: samsung-galaxy-ring-2024
corpus: private
form factor: ring
creator: Samsung Electronics Co., Ltd.
disclosure: Samsung Electronics. ‘Samsung Galaxy Ring’, announced July 2024 — a finger ring with infrared photoplethysmography, an IR skin-temperature sensor, and a 3-axis accelerometer, deriving heart rate, heart-rate variability, skin temperature, sleep staging, activity, snore detection, and (with cycle-tracking) menstrual-cycle predictions.
ip status: patented
sensors: sensor-ppg, sensor-skin-temperature, sensor-accelerometer
algorithms: algo-hr, algo-hrv, algo-respiratory-rate, algo-sleep-staging, algo-snore-detection, algo-step-count
prior art notes: Discloses a smart ring with infrared PPG, IR skin-temperature, and accelerometer, deriving HR/HRV, sleep, snore detection, activity, and menstrual-cycle prediction — a Samsung entry directly in the wake of [[oura-ring-gen1-2015]] and the [[asada-mit-wearable-ring-sensor-2003]] academic root. Product-side reference in the ring × PPG × HRV cross-cut alongside Oura.

Cross-cut: algo-sleep-staging