1. Influence of skin type and wavelength on light wave reflectance
- Author
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Bennett A. Fallow, Takashi Tarumi, and Hirofumi Tanaka
- Subjects
Adult ,Male ,Materials science ,Light ,Optical Phenomena ,Infrared ,Skin Pigmentation ,Health Informatics ,Signal-To-Noise Ratio ,Green-light ,Critical Care and Intensive Care Medicine ,law.invention ,Young Adult ,Optics ,Heart Rate ,law ,Photoplethysmogram ,Humans ,Photoplethysmography ,Exercise ,Monitoring, Physiologic ,Skin ,business.industry ,Middle Aged ,Wavelength ,Optical phenomena ,Anesthesiology and Pain Medicine ,Modulation ,Female ,sense organs ,business ,DC bias ,Light-emitting diode - Abstract
Purpose: A new application of photoplethysmography (PPG) has emerged recently to provide the possibility of heart rate monitoring without a telemetric chest strap. The aim of this study was to determine if a new device could detect pulsation over a broad range of skin types, and what light wavelength would be most suitable for detecting the signals. A light emitting diode-based PPG system was used to detect changes in pulsatile blood flow on 23 apparently healthy individuals (11 male and 12 female, 20–59 years old) of varying skin types classified according to a questionnaire in combination with digital photographs with a skin type chart. Four different light wavelengths (470, 520, 630, and 880 nm) were tested. Normalized modulation level is calculated as the AC/DC component ratio and represents the change in flow over the underlying constant state of flow or perfusion. Results: In the resting condition, green light wavelength (520 nm) displayed greater modulation (p
- Published
- 2013
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