Intersection cross-cut: sensor-spo2 ∩ algo-respiratory-rate

Axes: sensors × algorithms

4 corpus entries disclose both tags.

Earliest disclosure: 2020-01-05

These entries are the direct inputs to OBVIOUSNESS_TEMPLATE.md. Any patent claim combining these two elements is anticipated or rendered obvious by the chain below.

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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.

Masimo W1 (2022) — first FDA-cleared continuous wrist medical-grade pulse oximetry watch (2022-05)

• id: masimo-w1-2022
• corpus: private
• form factor: watch
• creator: Masimo Corp.
• disclosure: Masimo Corp. ‘Masimo W1’ health-tracking watch, announced May 2022 — a wrist-worn device performing continuous medical-grade pulse oximetry (SpO2), pulse rate, perfusion index (PI), pleth variability index (PVi), respiratory rate from the PPG, and HRV, using Masimo’s SET/rainbow signal-extraction algorithms. (FDA cleared as a continuous-monitoring medical device.)
• ip status: patented
• sensors: sensor-ppg, sensor-spo2, sensor-multi-wavelength-ppg, sensor-accelerometer
• algorithms: algo-spo2-estimation, algo-hr, algo-hrv, algo-respiratory-rate
• prior art notes: Discloses a wrist-worn device performing continuous medical-grade pulse oximetry — SpO2, PR, perfusion index, PVi, RR-from-PPG, HRV — using established signal-extraction methods, distinguished from consumer spot-check SpO2 by continuous operation and clearance for medical use. Anticipates wrist-continuous-medical-SpO2 claims from 2022; the underlying two-wavelength SpO2 method is much older ([[aoyagi-1974-two-wavelength-pulse-oximetry]], [[mendelson-ochs-1988-reflectance-pulse-oximetry]], [[iso-80601-2-61-pulse-oximeter-equipment-2011]]). Product-side anchor for the watch × continuous-SpO2 cross-cut.

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.

H-Watch (Magno et al., 2024) — open-source ARM Cortex-M4F + ML + NB-IoT + energy-harvesting research smartwatch (2024)

• id: h-watch-magno-2024
• corpus: academic
• form factor: watch
• creator: Michele Magno et al. (ETH Zürich and collaborators)
• disclosure: Magno M, et al. ‘H-Watch: A Multi-Sensor Smart Wearable for COVID-19 Symptom Monitoring with ML and Energy Harvesting.’ arXiv:2407.21501 (2024). Fully open-source smartwatch hardware + firmware for symptom monitoring: ARM Cortex-M4F MCU, on-device ML inference, NB-IoT cellular connectivity, integrated energy harvesting + battery. https://arxiv.org/abs/2407.21501
• ip status: public-domain
• sensors: sensor-ppg, sensor-spo2, sensor-skin-temperature, sensor-accelerometer
• algorithms: algo-hr, algo-spo2-estimation, algo-respiratory-rate, algo-activity-classification
• prior art notes: Discloses a fully open-source research smartwatch combining multi-sensor vitals (PPG/SpO2/temperature/IMU), on-device ML inference, NB-IoT direct cellular connectivity (no phone required), and integrated energy harvesting to extend battery life — published with full hardware design and firmware. Prior art for symptom-monitoring smartwatch claims reciting any of those elements from 2024. Establishes that the cellular-connected open-hardware ML-enabled smartwatch is a published research design.