Wearable Dual-Mode Biosensing System for Dynamic Light Dosimetry in Tissues

Phototherapy is a physical treatment modality that utilizes natural or artificial light sources and harnesses radiant energy to treat diseases. Dynamic monitoring of the actual light dose received by tissues is crucial to the success of phototherapy. However, most current phototherapy devices feature bulky and complex hardware and depend on fixed parameters or surface measurements for dose estimation, failing to provide precise, real-time monitoring of light dose distribution that is tailored to individual users, specific treatment sessions, and different body regions. Furthermore, most of these devices are incapable of generating tunable and stable LED light. This study presents a preliminary diffusion equation-based proof-of-concept for a wearable, integrated dual-mode sensing system for real-time dynamic monitoring of tissue light dose and temperature change. The system, controlled by a single-chip microcontroller, rapidly extracts key tissue optical parameters via a custom multi-wavelength LED optical probe and provides real-time feedback on light dose distribution through a dynamic tissue optical simulation model. To expand the monitoring dimensions, the system innovatively integrates a thermal sensor. This sensor enables synchronous monitoring of the temperature field in the treatment area, thereby allowing for an estimation of the combined photothermal effect. The system features a compact design, user-friendly operation, fast and stable communication, and repeatable and reliable detection. With promising clinical application prospects, it holds the potential to evolve into a portable, home-use, safe, effective, wearable, and cost-effective phototherapy device.