Personalized and Explainable Blood Pressure Estimation from PPG

Overview


Continuous cuffless blood pressure (BP) monitoring using photoplethysmography (PPG) offers a promising solution for personalized healthcare. However, existing methods have two major limitations. Handcrafted feature-based approaches rely on precise fiducial point detection and are limited to short-term analysis, while deep learning models, despite their accuracy, often operate as black boxes with limited physiological interpretability.


Proposed Framework


To address these challenges, the authors propose a physiology-guided hybrid framework for personalized BP estimation that couples:


  • A convolutional neural network (CNN) branch capturing global and local waveform dynamics
  • A morphology-prior branch that explicitly encodes person-specific vascular characteristics

By embedding a morphology-based feature set that explicitly encodes individual vascular characteristics, the proposed framework enhances personalization and reduces dependence on large-scale training datasets.


Results


Evaluated on a subset of the MIMIC-III database under a subject-specific (personalized) testing protocol, the proposed personalized physiology-guided hybrid approach achieved:


  • Mean absolute error (MAE) of 3.77 mmHg for systolic BP
  • MAE of 2.36 mmHg for diastolic BP

These correspond to relative improvements of 43.7% and 32.4% over a subject-specific (personalized) CNN-only baseline.


Interpretability


SHAP-based analysis confirmed that the introduced morphology-prior features align with individual vascular characteristics, reinforcing per-subject interpretability.


Significance


These findings highlight the potential of personalized, physiology-guided hybrid learning with novel morphological descriptors for accurate and explainable BP monitoring in real-world settings.


Publication Details


via ArXiv CV

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