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Published on: March 22, 2019
Feasibility study of a single- and multiple-source near-infrared phase-modulation device for characterizing biologic
K A Kang1, D F Bruley, B Chance
1Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County 21250, USA.
Biomedical Instrumentation & Technology
|July 1, 1997
Summary
Near-infrared (NIR) spectroscopy offers a noninvasive method for biological analysis. This study details phase-modulation devices for improved system identification and heterogeneity detection in tissues.
Area of Science:
- Biomedical Optics
- Spectroscopy
- Medical Imaging
Background:
- Near-infrared (NIR) spectroscopy is a cost-effective, noninvasive optical technique for characterizing biological and physiological systems.
- Applications include measuring oxygen saturation, cytochrome oxidase, and glucose concentrations, as well as diagnostic imaging for tumor localization, hematoma detection, and deep vein thrombosis.
- Current NIR modalities include time-resolved spectroscopy (TRS), continuous-wave spectroscopy (CWS), and phase-modulation devices.
Purpose of the Study:
- To describe single-source and multiple-source (in- and anti-phased) phase-modulation devices.
- To demonstrate their application in system identification and heterogeneity detection.
- To illustrate the sensitivity of phased arrays for detecting absorbers and heterogeneities.
Main Methods:
- Description of single-source and multiple-source (in- and anti-phased) phase-modulation devices.
- System identification using phase and intensity information for homogeneous systems.
- Illustration of phase and intensity changes with one and two absorbers.
- Demonstration of phased array sensitivity and use of amplitude-modulated phased arrays for heterogeneity detection.
Main Results:
- Phase and intensity information correlate with system and instrumental parameters in homogeneous systems.
- Phase and intensity changes due to the presence of one and two absorbers were illustrated.
- The sensitivity of in- and anti-phased phase-modulation devices (phased arrays) was demonstrated.
- Amplitude-modulated phased arrays proved effective for heterogeneity detection.
Conclusions:
- Phase-modulation NIR spectroscopy, particularly with phased arrays, enhances system identification capabilities.
- These devices offer improved sensitivity for detecting absorbers and heterogeneities within biological tissues.
- The technology holds promise for advanced diagnostic imaging and physiological monitoring.
