Collision Avoidance in Healthcare Robotics Using mm-Wave Radar Fusion: A Hygienic and Fail-Safe Approach

Autonomous medical systems must meet stringent hygiene and safety requirements while operating reliably in dynamic clinical environments. This paper presents a collision avoidance system based on the fusion of two mm-wave radar technologies - frequency modulated continuous wave (FMCW) and pulsed coherent radar (PCR). The system is fully integrated behind sealed covers of medical devices and enables unobtrusive and hygienic use without compromising functionality. We demonstrate that both radar types provide robust detection of dynamic obstacles, even through layers of disinfectants, blood and polycarbonate materials. A fail-safe system architecture based on redundant sensor paths and dual microcontrollers ensures reliable operation under fault conditions. Experimental validation on a robotic X-ray system confirms the responsiveness, accuracy and suitability of the system for clinical integration. The results show that radar fusion offers a promising path to hygienic and certified safe motion planning in healthcare robotics.