Biogeophysical Admittance Spectroscopy (BAS): A Unified Multimodal Framework for Reagent-Free Solid-State Diagnostic Support

This paper presents the unified BAS (Biogeophysical Admittance Spectroscopy) theoretical framework with integrated BCO (BAS Central Orchestrator), a technology designed specifically to aid in diagnostics through rapid triage in vulnerable populations. The system integrates an extensible N-domain architecture (N ≥ 10) distributed across a multi-node ESP32-S3 cluster. We detail the biological and physical-mathematical foundations of each domain (Optical, Dielectric, Inductive, Electrochemical, Volatile, Photonic, Thermodynamic, Autofluorescence, Rheological, Magnetohydrodynamic), along with the distributed hardware architecture, BAS-Link communication protocol, physics-informed inference algorithms (PINN), and uncertainty budgets. The fundamental objective is to provide diagnostic technological sovereignty, demonstrating the viability of a low-cost portable distributed system capable of reducing health inequity through accessible point-of-care diagnostic support with hardware resilience and scalability.