BioShield-12: A 3D-Printed Conformal Chest Shield for Wireless 12-Lead ECG Acquisition

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Medical Devices

Background:

• Manual electrode placement in wearable ECG systems causes positional errors, degrading signal quality and multi-lead accuracy.
• Clinical 12-lead ECG systems are accurate but bulky and operator-dependent, limiting remote and prehospital use.
• Current wearable ECGs offer mobility but struggle with limited lead coverage, comfort, and connectivity.

Purpose of the Study:

• To introduce BioShield-12, a novel, anatomically adaptive shield for consistent multi-site electrode placement in wearable ECG systems.
• To enable accurate 12-lead electrocardiogram (ECG) reconstruction from a single-shield design.
• To address the challenge of inter-session variability in wearable ECG electrode positioning.

Main Methods:

• Fabrication of an anatomically adaptive shield using thermoplastic polyurethane (TPU) via fused deposition modeling (FDM).
• Design based on anthropometric data from a sizing cohort of ten healthy adults.
• Mechanical characterization of TPU for wearable substrate suitability (toughness, elastic modulus).
• Feasibility validation using a research-grade reference (BIOPAC MP36) in twenty healthy subjects.

Main Results:

• TPU demonstrated suitable mechanical properties for a compliant wearable substrate (toughness: 34.4 MJ/m³, elastic modulus: 79.1 MPa).
• Consistent signal fidelity was achieved during validation (SNR: 17.5-22.5 dB; Pearson r: 0.93-0.98; PLIR: 1.0-3.2 × 10⁻⁵).
• Feasibility of 12-lead ECG reconstruction using the BioShield-12 was confirmed.

Conclusions:

• BioShield-12 offers a proof-of-concept for an additive manufacturing-based conformal electrode interface.
• The shield design eliminates placement variability, enhancing wearable ECG reliability.
• This approach overcomes critical challenges in wearable ECG systems, improving multi-lead representation and signal accuracy.