Multi-chip LEDs can read disease risk through the skin by measuring advanced glycation end-products (AGEs), which are linked to diabetes complications, cardiovascular events, and chronic kidney disease. The new wavelength combination supports both heart rate monitoring and AGE measurements.
AGEs are heterogeneous molecules formed when sugars react non-enzymatically with proteins and lipids, playing a decisive role in the development of chronic age-related diseases. Some AGEs are fluorescent, emitting light in the blue–green range when excited by specific wavelengths, such as UV-A.
How Multi-Chip LEDs Work
Single-wavelength AGE readers exist, but integrating three chips with UV-A, green, and IR into one module multiplies the application options. The UV-A chip excites fluorescent AGEs in skin collagen, generating a diagnostic autofluorescence signal. The green chip can be used for heart rate monitoring and as a second excitation wavelength to probe different AGE/oxidation species.
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The IR chip enables simultaneous photoplethysmography for heart rate, perfusion, and hydration, potentially measuring stress due to variations in blood flow. Combining this with AGE autofluorescence lets one correlate biochemical risk with hemodynamic parameters in a single device.
Technical Considerations
A purpose-built optical module that combines UV-A excitation with green spectral probing and IR physiological sensing converts the established science of AGE autofluorescence into an actionable, multi-modal vital sign. This approach builds on validated Skin Autofluorescence work and extends it by improving specificity and adding physiological context.
The latest multi-chip LED SFH 7019 by ams OSRAM combines chips for green, IR, and UV-A, supporting both heart rate monitoring and AGE measurements. A matching photodiode, SFH 2705U, improves the accuracy of skin autofluorescence measurement by preventing UV light from reaching the detector.
With careful engineering for spectral fidelity, skin-type compensation, and UV safety, multi-chip LEDs such as the SFH 7019 are uniquely positioned to supply the key illumination building blocks that will bring AGE-based risk assessment into routine care, according to Stephan Haslbeck, Product Manager at ams OSRAM.
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Enabling New Medical Applications
The technical progress and purpose-built LED in combination with matching photodiodes form a complete optical sensing solution, paving the way for new and advanced medical applications in the field of vital sign monitoring and non-invasive procedures.
Compact modules embedded in home-care devices, wearable patches, or handheld exam tools allow longitudinal tracking of AGE trends. Nephrology and dialysis triage, as well as clinical research and drug trials, can also benefit from multi-spectral autofluorescence, providing a sensitive, non-invasive biomarker.
The references cited in the report support the link between skin autofluorescence and long-term disease risk, highlighting the potential of multi-chip LEDs in medical applications.