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Sensing oxygen through skin using a red diode laser and fluorescence lifetimes
1Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County 21228, USA.
Biosensors & Bioelectronics
|January 1, 1995
Summary
This study demonstrates non-invasive oxygen sensing through skin using red light and specialized probes. Measuring fluorescence lifetimes overcomes limitations of intensity-based methods for reliable subdermal sensing.
Area of Science:
- Biomedical Optics
- Sensing Technology
- Photochemistry
Background:
- Transcutaneous optical sensing faces challenges from light scattering and absorbance by skin.
- Existing methods lack probes excitable above 600 nm and are sensitive to intensity fluctuations.
- Current techniques struggle with probe concentration changes and inner filter effects.
Purpose of the Study:
- To develop a method for transcutaneous optical sensing of oxygen.
- To overcome limitations of existing absorbance and fluorescence intensity measurements.
- To demonstrate the feasibility of subdermal oxygen sensing using red light and fluorescence lifetime measurements.
Main Methods:
- Utilized red light (635-680 nm) for deep skin penetration.
- Employed an oxygen-sensitive osmium-ligand complex.
- Measured fluorescence lifetimes using phase fluorimetry with long-lived fluorophores.
Main Results:
- Successfully demonstrated oxygen sensing through a layer of skin.
- Fluorescence lifetime measurements proved insensitive to intensity drifts and concentration variations.
- Showcased potential for simple, inexpensive instrumentation for subdermal sensing.
Conclusions:
- Developed a novel approach for non-invasive oxygen monitoring.
- Fluorescence lifetime measurements offer a robust alternative to intensity-based optical sensing.
- This paradigm enables future non-invasive sensing of other analytes transcutaneously.