Blueprint: Low-Cost Pulse Oximeter — Build and Implementation Specification

Build and implementation specification for the discrete-part transmissive finger-clip pulse oximeter (US $17.50 bill of materials) designed in the source paper: parts list, operating point, circuit and optical layout, firmware blanking behaviour below 1% perfusion index, melanin-stratified calibration procedure, operating envelope and failure corners, all carried from the paper's propagated accuracy budget. DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT, NOT CLINICALLY TESTED. Blueprint for the design published as DOI 10.5281/zenodo.24108850.