Infrared thermography has emerged as a non-invasive technique for monitoring physiological processes in clinical rehabilitation; however, its adoption remains limited due to challenges in usability, data integration, and measurement reliability. This work presents the design and development of a thermographic medical device with a user-centered graphical user interface (GUI), integrating real-time thermal acquisition, processing, and analysis within a unified clinical workflow. The proposed system is based on a modular architecture that decouples radiometric processing from visual representation, enabling accurate temperature measurements while maintaining low-latency interaction. A deterministic data pipeline is implemented to support real-time visualization (~30 fps), region-based thermal analysis, and structured data persistence. The interface was developed using an iterative usability engineering approach, incorporating feedback from clinical specialists to optimize interaction, reduce cognitive load, and improve workflow efficiency. Device validation was performed using a controlled gray-body cavity as a reference source, ensuring traceability and measurement consistency under standardized conditions. Preliminary evaluations in a clinical-like environment demonstrate stable thermal acquisition, reliable measurement behavior, and improved usability during data capture, analysis, and reporting tasks. This work contributes a clinically-oriented thermographic system that combines validated measurement processes with a user-centered interface design, highlighting the importance of integrating computational architecture and human–computer interaction principles in medical device development.