M hollander and j hagen

Abstract accepted for platform presentation at SPIE Photonics West 2026

Photobiomodulation Therapy (PBMT) uses visible and near-infrared (600-1100 nm) light to enhance physical and cognitive performance, promote recovery, and support overall wellness. While medical-grade laser-based PBMT is well studied in clinical settings, the recent proliferation of LED-based consumer devices has outpaced the development of validated measurement standards or evidence-based protocols.

This presentation highlights two sequential studies. The first establishes validated methodologies for measuring irradiance and spectral output from PBMT devices, including panels, wearables, and full-body light beds. Using various measurement devices, such as a spectroradiometer, silicon photodiode meter, and thermopile sensor, we documented significant variability in the measured irradiance value, up to 763 mW/cm², depending on the measurement configuration employed. Less concern was found with spectral measurements, where most devices aligned within ±10 nm of manufacturer claims. The vastly variable irradiance findings, however, emphasize the necessity of standardized protocols to ensure accurate dosimetry and device comparisons. In this presentation, we will detail the proposed validation methodology for the three categories of PBMT devices tested. 

The second study applied this validated measurement framework to inform device selection and application of PBMT in a single-blinded, randomized, sham-controlled clinical trial. Military-affiliated participants completed two 4-week blocks (sham and active) using full-body LED PBMT devices. Blood samples were analyzed for inflammatory and stress biomarkers (e.g., TNF-α, IL-6, cytokines), and participants completed numerous validated wellness surveys throughout their time in the study. Comprehensive analyses of heart rate and sleep data collected via wearable devices, subjective survey measures, and objective blood biomarkers will be finalized and presented at the time of the conference.

Together, these studies improve the technical accuracy of PBMT measurements and expand knowledge of its clinical effects, providing a solid foundation for researchers and practitioners to develop evidence-based guidelines and implement LED-based wellness interventions more effectively.