OpenBalance ⚖️🔓

An Open-Platform, Multi-Cell Framework for Unconstrained Posturography and Balance Assessment

OpenBalance is an open-source, hardware-agnostic framework designed to democratize advanced biomechanical balance assessment. By breaking the vendor lock-in of proprietary, high-cost medical devices, OpenBalance enables research laboratories, sports facilities, and clinical institutions to implement a highly precise, flexible posturography system using customizable distributed force cells.

Unlike conventional monolithic force plates or rigid four-quadrant systems (such as Tetrax), OpenBalance introduces a novel methodological approach using a multi-cell array (e.g., 4x4 matrix). This architecture allows for unconstrained foot placement, ensuring subjects can adopt their natural, anthropometrically comfortable stance—which is particularly crucial in orthopedic rehabilitation (e.g., post-operative hip and knee arthroplasty).

🚀 Key Features

• Open Architecture & No Vendor Lock-In: Pure open-source software (Python/NumPy) and flexible hardware principles. No encrypted data structures, no hidden subscription walls.
• Unconstrained Stance & Variable Geometry: Supports custom-positioned, mechanically decoupled sub-platforms. The software dynamically handles coordinate transformation via geometric offsets.
• Cascading Mathematical Framework: Implements a rigorous two-stage Center of Pressure (COP) calculation (localized sub-segment COPs fused into a global COP) based on established biomechanical models (Winter, 2009).
• Decoupled Clinical Metrics: Independently quantifies static postural alignment/deficits via the Weight Distribution Index (WDI) and dynamic equilibrium stability (Postural Sway).
• High Dynamic Precision: Designed for discrete, low-mass load cells to bypass the inertial mass artifacts of heavy force plates and the shear-force limitations of pressure-sensing mats under dynamic perturbations.

📐 Mathematical Principle

OpenBalance handles the spatial data fusion of distributed force cell arrays. The global COP is computed as a force-weighted average of the localized sub-platform coordinates, mapped into a unified global coordinate system:

$$X_{global} = \frac{\sum_{i=1}^{4} \left( (X_{i,local} + X_{off,i}) \cdot F_i \right)}{F_{total}}$$

Where $X_{off,i}$ represents the deterministic geometric offset of the independent sub-platform from the absolute geometric origin $(0,0)$.

🛠️ Repository Contents

This repository contains the core methodological framework and open-source assets:

• /data : Testdatasets.
• /docs : Published Paper.
• /hardware_concept : PDF Document for the dimension.
• /src : Python algorithms utilizing NumPy for element-wise, vectorized data processing (localized/global COP calculation, and WDI extraction).

🤝 Contributing & Open Science

This project is a scientific initiative to open up posturography for researchers and sports scientists worldwide. We welcome contributions regarding:

• Signal processing pipelines (e.g., advanced filtering techniques).
• Real-time visualization dashboards (Python/Dash/Streamlit).
• Hardware interface integrations (ADC data streaming, firmware).

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.