145 - Standardized Bilirubin Phototherapy Systems (SBPS): A Metrology- Driven Platform for Accurate, Real-Time Irradiance Measurement in Neonatal Phototherapy

Publication Number: 3139.145

Mahesh L. Sampat, Children's Health, Lakewood, CA, United States

Background: Neonatal phototherapy remains the standard intervention for hyperbilirubinemia, but persistent variability in delivered irradiance-and inadequate tools for real-time measurement and documentation-limit optimization of treatment. The American Academy of Pediatrics (AAP) technical reports and recent commentary (e.g., "Neonatal Phototherapy-The Need to Measure and Document", JAMA Pediatrics, 2024) highlight the unmet research need for cost-effective systems that reliably measure and document spectral irradiance in clinical settings.

Objective: To develop and validate a Standardized Bilirubin Phototherapy System (SBPS) that leverages metrology-grade irradiance measurement, spectrally matched LED sources, and real-time feedback control to support the AAP-identified research need for accurate measurement and documentation of phototherapy irradiance.

Design/Methods: The SBPS prototype combines three key elements:

1. A uniform irradiance field generated via integrating-sphere-inspired optics with a calibrated 475 nm narrowband LED source, designed for neonatal phototherapy wavelengths.

2. A radiometer (Patent Pending) with a spectrally matched narrowband sensor (rather than a broadband spectral filter) for accurate irradiance measurement under LED sources.

3. A microcontroller-based closed-loop algorithm that receives transcutaneous bilirubin (TcB) input and dynamically adjusts LED output to maintain target irradiance levels. Bench testing was conducted using NIST-traceable spectroradiometric calibration to assess spectral uniformity, irradiance accuracy, and control stability.

Results: Preliminary instrumentation data demonstrate > 95% spatial uniformity across the treatment zone and measured irradiance error of less than ±2% within the 475 ±5 nm therapeutic band. The closed-loop feedback system maintained set-point irradiance within ±5% over continuous long-duration operation. These results indicate the SBPS meets the AAP-identified need for a system capable of cost-effective, accurate, real-time measurement and documentation of spectral irradiance in neonatal phototherapy.

Conclusion(s): The SBPS presents a new metrology-aware platform that aligns with the research priorities outlined by the AAP and recent expert commentary. By enabling precise, real-time measurement and documentation of spectral irradiance, the SBPS has the potential to standardize neonatal phototherapy dosing, support research studies, and ultimately enhance clinical safety and effectiveness of treatment.

SBPS Prototype Demostration