@misc{indiciaee7b580c57088,
  title = {Heart rate persistence index (HRPI): a threshold-free wearable metric for sustained HR elevation},
  author = {Zhang, R.},
  year = {2026},
  doi = {10.64898/2026.04.07.716987},
  url = {https://www.biorxiv.org/content/10.64898/2026.04.07.716987v1},
  note = {Source identifier: 10.64898/2026.04.07.716987}
}