Biomedical Embedded AI

PPG–HRV Cognitive Load

Earlobe PPG acquisition, IBI/HRV features, and CNN/Transformer cognitive-task classification. First-author CICS’25 paper.

First-author paper · acquisition and classification code
Research pipeline connecting a PPG sensor, STM32 firmware, HRV preprocessing, and CNN Transformer evaluation

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01

Problem

The project carries PPG sample timing through IBI/HRV feature construction and cognitive-task classification.

02

Architecture

Earlobe PPG sensor/AFE → STM32 acquisition → IBI/HRV preprocessing → CNN+Transformer evaluation → comparison of fold results and paper metrics under separate conditions.

03

Hardware and Software

  • PPG AFE
  • STM32
  • Python
  • HRV
  • CNN
  • Transformer

04

Data Flow

PPG sample timing is preserved through peak/IBI calculation before HRV features and sequences enter the classifier.

05

Methodology

  • Preprocessed PPG acquisition timing and peak-derived IBIs
  • Constructed time- and frequency-domain HRV features
  • Evaluated CNN+Transformer models and compared results by evaluation condition

06

Results

  • Paper abstract/conclusion AUC of 0.99
  • Paper abstract/conclusion F1-score of 0.992
  • End-to-end PPG/STM32/HRV/CNN research pipeline

What I worked on

  • IBI/HRV preprocessing and feature construction
  • CNN+Transformer evaluation pipeline
  • Comparison of paper metrics and code-archive metrics under their respective evaluation conditions

Code and results

  • PPG AFE, STM32 firmware, and Python source
  • Fold-result CSV files and a public paper PDF
  • Group-level aggregate plots

Design scope and next steps

Evaluation: paper abstract/conclusion metrics, body Fold 5, and separate code-run results are labeled individually.

PPG peaks supply IBI/HRV features for CNN and Transformer classification. Paper averages and archived fold results retain their respective evaluation conditions.

Publication first-page preview