Reflectance Pulse Oximetry for Blood Oxygen Saturation Measurement from Diverse Locations-A Preliminary Analysis

Abstract

Blood oxygen saturation level (SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) is a clinically accepted vital sign for patient care and diagnostics. Oximeters are widely used by people suffering from asthma, congestive heart failures and pulmonary disorders as part of their routine care. Transmittance and reflectance pulse oximeters play a pivotal role in patient care and clinical decision making. In this paper, we study the feasibility of using reflectance photo plethysmography (PPG) for SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> monitoring from various measurement sites on body. A preliminary study was conducted in a clinical setting on 10 subjects with pulmonary disorders. Arterial blood gas (ABG) analysis was used as a reference measure in the study. An SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> data acquisition platform was developed, which uses custom-made dual wavelength reflectance SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensor probes, Nellcor <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">™</sup> transmittance probe for beat to beat SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> measurement. The preliminary analysis of beat to beat reflectance PPG signal from finger, forehead, wrist and chest concur well with the reference measurement and gives enough scope to measure SpO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> from various measurement sites like finger, forehead, wrist and chest.