Wearable Printed Strain – Temperature Sensor for Erectile Dysfunction Monitoring

Abstract

This work presents a wearable strain–temperature sensing system that combines a stretchable strain sensor with a temperature sensor to monitor penile erection events and improve the objectivity of Erectile Dysfunction (ED) assessment. ED is often evaluated with questionnaires or mechanical rigidity tools, which offer limited physiological detail and make it difficult to distinguish between vascular and neurogenic causes [1]. By measuring both deformation and temperature at the same location, our approach aims to provide a more informative signal. The sensor patch is made on a biocompatible Flexdym substrate by screen-printing conductive silver inks. This process yields a thin, flexible structure that can be integrated into future wearable systems. The strain sensor measures axial stretch of the penile shaft through resistance changes during elongation. The temperature sensor tracks skin temperature changes linked to blood flow during erection. Prior reports indicate that penile skin temperature can rise by about 0.5–2.5 °C during erection with an average rise of ~1.5°C in healthy subjects [2]. To detect such changes reliably, our temperature channel provides ±0.07 °C resolution with a response time under 10 seconds. We calibrated the strain channel under controlled uniaxial loading and evaluated linearity, hysteresis, and repeatability. We also characterized the temperature channel against a precision reference to determine accuracy and response time. Separate characterizations confirm accurate strain detection during programmed elongation and sub-degree thermal resolution with fast response. Because the device measures both deformation and perfusion in a single, thin, flexible patch, it offers a clear path to skin-conformal use and future integration with wireless readout and data-fusion methods for objective, non-invasive ED assessment.