PaperarXiv:2609.27473

Learning Where to Look: A Shared Relative-Alignment Module for Time-Series Forecasting and PPG-to-Vital-Sign Reconstruction (ROOSTER)

Preprint2026Added Sep 26, 2026

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Authors: Ragamayi Puli, Shunya Nagashima

arXiv preprint

TL;DR

ROOSTER learns a periodic-comb relative-alignment bias so one conditioning module serves both multivariate forecasting and wrist PPG→clinical waveform (e.g. ECG) reconstruction. Reports outperforming published baselines on four HR/RR reconstruction benchmarks (details in PDF).

  • Form factor: wrist

Abstract

PPG-to-vital-sign reconstruction turns a wrist-worn photoplethysmogram into clinical waveforms such as the ECG. Long-horizon multivariate time-series forecasting underpins planning in energy, weather, and traffic. Both generate a target sequence from a condition sequence, and current models hard-code where each target position reads it, as a same-position copy or seasonal recurrence, so neither transfers between tasks. We propose ROOSTER, one conditioning module that handles vital-sign reconstruction and time-series forecasting alike by learning this correspondence. Its core is a periodic-comb bias over the target-condition offset whose center, period, and sharpness are learned per head, so one module settles on the identity alignment or a seasonal lag and reports which it found. On vital-sign reconstruction from PPG, ROOSTER outperformed the published baselines on four heart-rate and respiratory-rate benchmarks. On multivariate time-series forecasting, it achieved the best horizon-averaged MSE on four benchmarks and outperformed the forecasting model it extends on 20 of 24 dataset-horizon settings under matched three-seed training. An ablation study indicated that the relative bias, not content matching, carried the alignment.

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Tasks & signals

Tasks

Heart rateSignal denoising

Signals

Keywords

HRRRreconstructionalignment

How it works

How Method works: Setup → Method → TargetSetup: Signals (PPG, ECG target); Form factor (wrist). Method: Method (Masked reconstruction). Target: Heart rate; Signal denoising.SetupSignals: PPG, ECG targetSignalsPPG, ECG targetForm factor: wristForm factorwristMethodMASK → RECONSTRUCTMethodMasked reconstructionTargetHeart rateHeart rateSignal denoisingSignal denoising

Cite this paper

APA

Puli, R., & Nagashima, S. (2026). Learning Where to Look: A Shared Relative-Alignment Module for Time-Series Forecasting and PPG-to-Vital-Sign Reconstruction (ROOSTER). arXiv preprint. https://arxiv.org/abs/2609.27473

BibTeX

@misc{puli2026learning,
  title         = {{Learning Where to Look: A Shared Relative-Alignment Module for Time-Series Forecasting and PPG-to-Vital-Sign Reconstruction (ROOSTER)}},
  author        = {Puli, Ragamayi and Nagashima, Shunya},
  year          = {2026},
  howpublished  = {arXiv preprint},
  eprint        = {2609.27473},
  archivePrefix = {arXiv}
}

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