Biomedical Embedded AI

PPG–HRV Cognitive Load

Traces timing integrity from earlobe PPG acquisition through IBI/HRV feature construction and CNN+Transformer classification.

Paper and code results kept separate
Research pipeline connecting a PPG sensor, STM32 firmware, HRV preprocessing, and CNN Transformer evaluation

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-reported average AUC of 0.85
  • Paper-reported F1-score of 0.82
  • End-to-end PPG/STM32/HRV/CNN research pipeline
01Problem

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

02Architecture

Earlobe PPG sensor/AFE → STM32 acquisition → IBI/HRV preprocessing → CNN+Transformer evaluation → comparison of fold resul...

03Method

Preprocessed PPG acquisition timing and peak-derived IBIs

04Result

Paper-reported average AUC of 0.85

A compact problem-to-result map generated from the project data used on this page.

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

Next steps

The paper-summary AUC/F1 and the code archive's five-fold metrics use different evaluation conditions. Next, I plan to rerun them with the same dataset split and metric definitions for a direct comparison.

I derived IBI and HRV features from PPG peaks and compared CNN and Transformer models. Metrics from the paper table and saved code runs use different evaluation conditions, so I list them separately.

Publication first-page preview