A Cable‐Driven Parallel Wire Robot for Probe Positioning and Tissue Palpation on Curved Phantoms

Abstract

Automated breast cancer screening has the potential to overcome the limitations of manual techniques, such as operator variability and the inability to image dense tissue. However, existing robotic solutions are often bulky, rigid, and unsafe for patient contact outside of clinical settings. Here, we present a wearable, cable‐driven parallel robot (CDPR) designed for precise ultrasound probe positioning and quantitative stiffness mapping on curved body surfaces. Unlike rigid manipulators, our system utilizes a lightweight, flexible architecture that ensures continuous skin contact through a Jacobian‐based tension optimization controller. We demonstrate that this framework effectively manages the static indeterminacy of the three‐cable mechanism, achieving sub‐2‐mm positioning accuracy on anatomically curved phantoms while strictly enforcing safety force constraints. Furthermore, we validate a novel dual‐modality capability: by monitoring cable tension during indentation, the system autonomously derives force–displacement curves to estimate soft tissue stiffness. This work bridges the gap between large‐scale medical robots and wearable health monitors, offering a pathway toward autonomous, hands‐free ultrasound imaging and biomechanical tissue characterization in nonclinical environments.