Viscoelastic Properties of Normal Skin and Basal Cell Carcinoma Evaluated by Non-Contact Palpation

This study provides a large-scale clinical validation of a non-invasive method to characterize the mechanical properties of tumoral and non-tumoral human skin, aiding dermatological diagnosis and establishing a database for future research. The non-contact UNDERSKIN device employs Fourier transform calculations to analyze surface wave dispersion generated by a focused airflow, via a skin-specific inversion model combined with a viscoelastic model. This digital palpation technology provides detailed insight into subsurface particle motion, revealing new mechanical responses of basal cell carcinomas (BCC). Conducted ex vivo on over 160 BCC and 40 healthy skin specimens, the results quantify the viscoelastic behavior of each skin layer. Although dermatologists can assess tissue firmness through palpation, they currently cannot objectively quantify it or determine its origins. This technique provides that missing quantification, linking tactile perception to specific biomechanical properties. By measuring where firmness originates within skin layers, this work offers valuable support for improving diagnosis, prognosis, treatment planning, surgical decisions, and the advancement of teledermatology applications.