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Paper

Real-time comparison of ML-enabled devices for compensatory reserve (CRM vs FDA-cleared CRI)

Carlos Bedolla, Jose M. Gonzalez, Ryan Ortiz, Krysta Amezcua, Sofia I. Hernandez Torres, Victor A. Convertino +1 more
Bioengineering2026CC BY 4.0
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Published articlePublication date: Jul 16, 2026Added to atlas: Oct 13, 2026Source
Citations0Crossref referencesChecked Oct 16, 2026
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Activity counts measure attention, not model quality. Missing counts are unknown. Publication status follows the linked source; a listed venue alone does not confirm peer review.

This study compared two PPG-based algorithms that estimate compensatory reserve, a measure of how close the body is to decompensating during blood loss. Twenty participants went through a lower body negative pressure (LBNP) chamber protocol that simulates progressive central hypovolemia, while a new compensatory reserve measurement (CRM) device and an FDA-cleared compensatory reserve index (CRI) device ran side by side on noninvasive PPG sensors. Pooled CRM and CRI values agreed closely (R² = 0.859) with a near-zero mean bias of 0.13%. The authors conclude that both devices track compensatory changes in real time, which could help with monitoring and triage in prehospital trauma care.

  • Signals: PPG
  • Result: pooled CRM vs CRI correlation R² = 0.859; Bland–Altman mean bias 0.13%
  • Result: mean early measurement time 20.52 min for CRM vs 17.92 min for CRI
At a glance
Venue
Bioengineering
Published
2026
DOI
10.3390/bioengineering13070817 (opens in a new tab)
arXiv
Not reported
PMID
42510482 (opens in a new tab)
Licence
CC BY 4.0 (opens in a new tab)
Signals
Not reported
Form factor
Not reported
Subjects
20 participants in a stepwise lower body negative pressure protocol
Code
Not reported
Added
Oct 13, 2026

Abstract

In this work, the real-time measurement of compensatory reserve metrics is compared during a simulated central hypovolemia clinical research study. We hypothesized that values generated from the compensatory reserve measurement (CRM) device would be statistically similar to those values generated from the compensatory reserve index (CRI) device. A study was conducted to collect data from noninvasive photoplethysmography sensors to validate the CRM against an FDA-cleared CRI device. Participants were placed in a lower body negative pressure (LBNP) chamber and underwent exposure to a stepwise protocol of increasing negative pressure. Data from both algorithmic devices were evaluated using multiple approaches: median error, median absolute error, and pooled Pearson correlations. Data were compared from 20 participants through the duration of the experiment. Pooled correlation analysis between CRM and CRI for all subjects and LBNP steps achieved R2 = 0.859, showing strong linear agreement. Bland–Altman analysis revealed a near-zero mean bias between CRM and CRI (0.13%). Each metric allowed for a mean early measurement time of 20.52 min for CRM and 17.92 min for CRI. Consistent with our hypothesis, the CRM device performed similarly to CRI, demonstrating that both models can track compensatory status changes with progressive central hypovolemia. The early, real-time predictive tracking of compensatory changes can be valuable for continuous monitoring and triaging in prehospital trauma environments.

Verbatim fromthe publisher's DOI record· Publisher licence: https://creativecommons.org/licenses/by/4.0/

Real-time comparison of ML-enabled devices for compensatory reserve (CRM vs FDA-cleared CRI): ChatPPG research summary card

Key results

0.859
R
Pooled CRM and CRI values agreed closely (R² = 0.859) with a near-zero mean bias of 0.13%

How it works

How Method works: Setup → Method → ResultSetup: Cohort (20 participants in a stepwise lower body negative pressure protocol); Signals (PPG). Method: Method. Result: Result (pooled CRM vs CRI correlation R² = 0.859; Bland–Altman mean bias 0.13%); Result (mean early measurement time 20.52 min for CRM vs 17.92 min for CRI).SetupCohort: 20 participants in a stepwise lower body negative pressure protocolCohort20 participants in a stepwise lower…Signals: PPGSignalsPPGMethodMethodResultResult: pooled CRM vs CRI correlation R² = 0.859; Bland–Altman mean bias 0.13%Resultpooled CRM vs CRI correlation R² =…Result: mean early measurement time 20.52 min for CRM vs 17.92 min for CRIResultmean early measurement time 20.52 min…
Cohort
20 participants in a stepwise lower body negative pressure protocol

Cite

@article{crm1dcnnlbnpcompensatory2026,
  title = {{Real-time comparison of ML-enabled devices for compensatory reserve (CRM vs FDA-cleared CRI)}},
  author = {Carlos Bedolla and Jose M. Gonzalez and Ryan Ortiz and Krysta Amezcua and Sofia I. Hernandez Torres and Victor A. Convertino and Eric J. Snider},
  year = {2026},
  journal = {Bioengineering},
  doi = {10.3390/bioengineering13070817}
}

History

  1. Added to the ChatPPG research hub

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