PaperarXiv:2509.12515

Rapid Adaptation of SpO2 Estimation to Wearable Devices via Transfer Learning on Low-Sampling-Rate PPG

Preprint2025Added Sep 26, 2026

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Authors: Zequan Liang, Ruoyu Zhang, Wei Shao, krishna Karthik, Ehsan Kourkchi, Setareh Rafatirad et al. (7 authors)

arXiv preprint (eess.SP, cs.LG) · In the proceedings of IEEE-EMBS International Conference on Body Sensor Networks 2025

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Liang, Zequan et al., "Rapid Adaptation of SpO2 Estimation to Wearable Devices via Transfer Learning on Low-Sampling-Rate PPG", arXiv:2509.12515, CC BY 4.0

TL;DR

Blood oxygen saturation (SpO2) is a vital marker for healthcare monitoring. Traditional SpO2 estimation methods often rely on complex clinical calibration, making them unsuitable for low-power, wearable applications.

  • Form factor: wrist

Abstract

Blood oxygen saturation (SpO2) is a vital marker for healthcare monitoring. Traditional SpO2 estimation methods often rely on complex clinical calibration, making them unsuitable for low-power, wearable applications. In this paper, we propose a transfer learning-based framework for the rapid adaptation of SpO2 estimation to energy-efficient wearable devices using low-sampling-rate (25Hz) dual-channel photoplethysmography (PPG). We first pretrain a bidirectional Long Short-Term Memory (BiLSTM) model with self-attention on a public clinical dataset, then fine-tune it using data collected from our wearable We-Be band and an FDA-approved reference pulse oximeter. Experimental results show that our approach achieves a mean absolute error (MAE) of 2.967% on the public dataset and 2.624% on the private dataset, significantly outperforming traditional calibration and non-transferred machine learning baselines. Moreover, using 25Hz PPG reduces power consumption by 40% compared to 100Hz, excluding baseline draw. Our method also attains an MAE of 3.284% in instantaneous SpO2 prediction, effectively capturing rapid fluctuations. These results demonstrate the rapid adaptation of accurate, low-power SpO2 monitoring on wearable devices without the need for clinical calibration.

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Tasks & signals

Tasks

SpO₂

Signals

Keywords

SpO2transfer-learningwearablelow-sample-rate

How it works

How Method works: Setup → Method → TargetSetup: Signals (PPG); Wavelengths (red, IR); Form factor (wrist). Method: Method. Target: SpO₂.SetupSignals: PPGSignalsPPGWavelengths: red, IRWavelengthsred, IRForm factor: wristForm factorwristMethodMethodTargetSpO₂O₂SpO₂
Wavelengths
red, IR

Cite this paper

APA

Liang, Z., Zhang, R., Shao, W., Karthik, K., Kourkchi, E., Rafatirad, S., et al. (2025). Rapid Adaptation of SpO2 Estimation to Wearable Devices via Transfer Learning on Low-Sampling-Rate PPG. arXiv preprint · In the proceedings of IEEE-EMBS International Conference on Body Sensor Networks 2025. https://doi.org/10.1109/BSN66969.2025.11337411

BibTeX

@misc{liang2025rapid,
  title         = {{Rapid Adaptation of SpO2 Estimation to Wearable Devices via Transfer Learning on Low-Sampling-Rate PPG}},
  author        = {Liang, Zequan and Zhang, Ruoyu and Shao, Wei and Karthik, krishna and Kourkchi, Ehsan and Rafatirad, Setareh and others},
  year          = {2025},
  howpublished  = {arXiv preprint · In the proceedings of IEEE-EMBS International Conference on Body Sensor Networks 2025},
  doi           = {10.1109/BSN66969.2025.11337411},
  eprint        = {2509.12515},
  archivePrefix = {arXiv}
}

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