Photoplethysmography (PPG) is a technique that permits noninvasive measurement of changes in the volume of tissues. A novel device uses PPG to assess changes in duodenal mucosal perfusion. When tested in septic piglets, data obtained using this device correlate with the blood lactate concentration and duodenal serosal microvascular blood flow as measured with a laser Doppler flowmeter. This new...

Infrared photoplethysmogram (IR-PPG) and magnetic resonance image (MRI) of the Mytilus galloprovincialis heart were obtained simultaneously. Heart rate was varied by changing temperature, aerial exposure and hypoxia. Higher heart rates (35-20 beat min-1) were usually observed at 20°C under the aerobic condition, and typical IR-PPG represented a single peak (peak v). The upward and downward slop...

OBJECTIVE The purpose of this study was to evaluate the clinical value and reproducibility of laser Doppler (LD) versus photoplethysmography (PPG) in the measurement of the systolic toe blood pressure. METHODS Toe blood pressure was measured in 60 patients in different stages of peripheral vascular disease with simultaneous digital sampling of PPG and two LD signals, each with a different fil...

This study was done to determine the correlation between glucose monitoring by fasting blood glucose or 2 hours postprandial blood glucose with HbA1c and fructosamine in type 2 diabetic patients. A total of 82 patients from the Primary Care Clinic were enrolled in the study. Fasting blood was drawn for fasting plasma glucose (FPG), glycated haemoglobin (HbA1c) and fructosamine. Two hours after ...

Activation of superoxide-producing NADPH oxidase of neutrophils requires the presence of cell membranes, cytosolic components and arachidonate and is markedly enhanced by non-hydrolysable analogues of guanine nucleotides, i.e. guanosine 5'-[gamma-thio]triphosphate and guanosine 5'[beta gamma-imido]triphosphate (p[NH]ppG). Gel filtration and ultrafiltration of the cytosol decreased the basal act...

OBJECTIVES Despite improvements in treatment modalities, large-for-gestational age (LGA) prevalence has remained between 30% and 40% among infants of mothers with type 1 insulin-dependent diabetes mellitus (TIDM). Our objective was to estimate LGA prevalence and examine the association between gestational weight gain (GWG) and prepregnancy body mass index (BMI) with LGA among mothers with TIDM....

Turcott RG, Pavek TJ. Hemodynamic sensing using subcutaneous photoplethysmography. Am J Physiol Heart Circ Physiol 295: H2560 –H2572, 2008. First published October 10, 2008; doi:10.1152/ajpheart.00574.2008.—Pacemakers and implantable defibrillators presently operate without access to hemodynamic information. If available, such data would allow tailoring of delivered therapy according to perfusi...

BACKGROUND Many researchers have attempted to acquire respiratory rate (RR) information from a photoplethysmogram (PPG) because respiration affects the waveform of the PPG. However, most of these methods were difficult to operate in real-time because of their complexity or computational requirements. From these needs, we attempted to develop a method to estimate RR from a PPG with a light compu...

In this paper, we propose a new method to distinguish between arousal and relaxation states by using multiple features acquired from a photoplethysmogram (PPG) and support vector machine (SVM). To induce arousal and relaxation states in subjects, 2 kinds of sound stimuli are used, and their corresponding biosignals are obtained using the PPG sensor. Two features—pulse to pulse interval (PPI) an...

Heart rate variability (HRV) is traditionally derived from RR interval time series of electrocardiography (ECG). Photoplethysmography (PPG) also reflects the cardiac rhythm since the mechanical activity of the heart is coupled to its electrical activity. Thus, theoretically, PPG can be used for determining the interval between successive heartbeats and heart rate variability. However, the PPG w...