Design of a Novel Stretchable Sensor for Systemic Sclerosis Diagnosis Through Skin Elasticity Measurement: A Simulation Study

The field of flexible devices is experiencing rapid growth in various fields, including healtcare, in order to improve currently inadequate diagnostic methods. Systemic Sclerosis (SSc), a rare autoimmune connective tissue disease, is characterized by high variability between patients and multi-organ involvement, for which there is not a standardized technique to quantify its status. One of the main symptoms of SSc is skin fibrosis, which leads to thickening and hardening of the skin, limiting joint mobility, thereby affecting patients' quality of life. Presently, the evaluation of SSc relies on the Rodnan Skin Score (RSS), a clinical method that is based on the clinician's experience, the skin thickness in different parts of the body. However, this type of approach has limitations in terms of accuracy and reproducibility. With this study, we propose a simulation of an innovative device to identify optimal stiffness for the development of a silicone patch to measure skin hardness in a standardized and reliable way in different anatomical areas and under different conditions. The simulation included phantoms with different stiffnesses, to reproduce physiological and pathological conditions of the anatomical forearm area. Results indicated that a soft material (440 kPa) is more effective in recognizing differences between pathological and physiological conditions, showing greater sensitivity in detecting changes in stiffness, in comparison with stiffer materials (740 kPa).