A Handheld Tool for Temporal and Spatial Young's Modulus Characterization of Soft Materials: Towards Point-of-Care Soft Tissue Assessment

Abstract Palpation is a simple, rapid, and important technique in physical examination, by which physicians assess tissue characteristics. It informs decisions about whether to advocate for expensive, time-consuming imaging procedures. Its primary limitation is its dependence on the clinician's experience, making standardization of findings challenging. Although various tools have been proposed to increase clinical objectivity, accessible and affordable devices capable of quantifying tissue properties remain scarce. This paper introduces SensoPal, a portable palpation-based system that measures the temporal and spatial Young’s modulus of soft materials, thereby offering quantitative non-invasive tissue stiffness assessment. SensoPal integrates a handheld tool with a miniature load cell and a magnetometer to measure Young’s modulus of soft materials. Coupled with a low-cost camera for position tracking, SensoPal generates spatial stiffness maps that visualize regions of varying stiffness across examined tissue. A user study demonstrated that SensoPal measured the Young’s modulus of soft materials at rates of ∼ 87% (±4%) for accuracy and ∼ 86% (±4%) for repeatability. Notably, in a localization task, deep-seated nodules that were not detectable by touch alone were identified using stiffness maps. These results establish SensoPal as a reliable, low-cost platform for quantitative tissue characterization, with potential applications in point-of-care diagnostics, telemedicine, and patient self-assessment.