Search results for "Photoplethysmogram"
showing 10 items of 84 documents
<title>Compact multi-functional skin spectrometry set-up</title>
2006
A portable fibre-optic spectrometry set-up has been assembled and tested for applications in skin diffuse reflectance spectrometry, laser fluorescence spectrometry and multi-wavelength reflection photoplethysmography (multi-PPG) studies. The spectrometry set was tested by diffuse reflectance and fluorescence measurements for diagnostics of skin vascular malformations and pigmented diseases such as nevi and melanoma . In addition, studies of microcirculation in blood vessels located at different depths from the skin surface were performed by the multi-PPG method. The results of skin diffuse reflectance and autofluorescence showed differences in spectra of healthy and pathologic skin. The par…
Optical multichannel monitoring of skin blood pulsations for cardiovascular assessment
2004
Time resolved detection and analysis of the skin back-scattered optical signals (reflection photoplethysmography or PPG) provide rich information on skin blood volume pulsations and can serve for cardiovascular assessment. The multichannel PPG concept has been developed and clinically verified in this work. Simultaneous data flow from several body locations allows to study the heartbeat pulse wave propagation in real time and to evaluate the vascular resistance. Portable two- and four-channel PPG monitoring devices and special software have been designed for real-time data acquisition and processing. The multi-channel devices were successfully applied for cardiovascular fitness tests and fo…
ESRA19-0692 Which preoperative tests before regional anaesthetic procedures?
2019
As we know, any regional anaesthesia technique stays under failure risks. What anaesthetists have to know about the regional block before let the surgeons start after regional anaesthesia? There are few positions which should be confirmed by tests. Firstly, detect the onset of successful sensitive, motor and sympathetic block. Secondly, confirm the correct area of the regional block. Furthermore, the anaesthetist should understand if the regional block performed under deep sedation or general anaesthesia will be effective also after the surgery. What we have to remember and what we need to check for this reason? Pain is subjective phenomenon. Are we determined as dependent on the patient‘s …
Optical Studies of the Capillary Refill Kinetics in Fingertips
2009
A new methodology for temporal analysis of the capillary refill processes by means of photoplethysmography (PPG) contact probe operating in the blue region of spectrum has been developed. A corresponding prototype device for finger measurements has been created and clinically tested. Results demonstrated that both AC and DC components of the blue PPG bio-signals are sensitive to the capillary occlusion and refill. Real-time measurements of the skin capillary refill kinetics by this technology can be used for noninvasive diagnostics of the peripheral perfusion disorders.
Miniature wireless photoplethysmography devices: integration in garments and test measurements
2012
Wireless PPG devices were developed and embedded in everyday clothes (bandage, scarf, cycling glove and wrist strap) to monitor cardiovascular state of free-moving persons. The corresponding software for measurements also has been developed and tested in laboratory. Real-time measurements of PPG signals were taken in parallel with a professional ECG reference device, and high correlation was demonstrated.
Estimating Heart Rate, Energy Expenditure, and Physical Performance With a Wrist Photoplethysmographic Device During Running
2017
BackgroundWearable sensors enable long-term monitoring of health and wellbeing indicators. An objective evaluation of sensors’ accuracy is important, especially for their use in health care. ObjectiveThe aim of this study was to use a wrist-worn optical heart rate (OHR) device to estimate heart rate (HR), energy expenditure (EE), and maximal oxygen intake capacity (VO2Max) during running and to evaluate the accuracy of the estimated parameters (HR, EE, and VO2Max) against golden reference methods. MethodsA total of 24 healthy volunteers, of whom 11 were female, with a mean age of 36.2 years (SD 8.2 years) participated in a submaximal self-paced outdoor running test and maximal voluntary exe…
Evaluation of nitroglycerin effect on remote photoplethysmogram waveform acquired at green and near infra-red illumination
2017
Assessment of skin microcirculation provides diagnostically valuable information during the early stages of pathologies. The simple, cost-effective and intrusive alternative to existing circulation assessment methods is remote photoplethysmography (rPPG). The objective of the present pilot study was to reveal an effect on sublingual administration of 1 mg nitroglycerin on systemic hemodynamic parameters and rPPG waveforms, at 810 nm and 530nm illumination. The protocol comprised 3 minutes of baseline recording, 15 minutes recording of NTG effect, 2 minutes of arterial occlusion and the following 3 min reactive hyperemia. Two PPG signals were acquired from glabrous skin of the middle finger …
Dual channel photoplethysmography studies of cardio-vascular response to the body position changes
2005
The dual-channel photoplethysmography studies of physiological responses during 3-stage orthostatic test were performed. Clear differences in heartbeat rate, pulse wave transit time and blood pressure variations of healthy volunteers and diabetic patients have been observed.
Effects of PEEP on Residual Vascularization in Oesophageal Substitution Gastroplasty by Surface Oximetry-Capnometry and Photoplethysmography
2003
<i>Objective:</i> To evaluate the effects of positive end-expiratory pressure (PEEP) on residual vascularization in gastric tubes for oesophageal replacement. <i>Design:</i> Experimental open study. <i>Materials:</i> Eleven mongrel dogs. <i>Methods:</i> Intestinal parietal blood flow was evaluated by photoplethysmography (PPG) and measurement of surface oxygen (PsO<sub>2</sub>) and carbon dioxide (PsCO<sub>2</sub>) tensions under basal conditions. After Akiyama’s tubular gastroplasty, three levels of PEEP were administered. At each level, fluids were infused to counter the drop in cardiac output. PPG, surface gas tensio…
Remote photoplethysmography system for unsupervised monitoring regional anesthesia effectiveness
2017
Determining the level of regional anesthesia (RA) is vitally important to both an anesthesiologist and surgeon, also knowing the RA level can protect the patient and reduce the time of surgery. Normally to detect the level of RA, usually a simple subjective (sensitivity test) and complicated quantitative methods (thermography, neuromyography, etc.) are used, but there is not yet a standardized method for objective RA detection and evaluation. In this study, the advanced remote photoplethysmography imaging (rPPG) system for unsupervised monitoring of human palm RA is demonstrated. The rPPG system comprises compact video camera with green optical filter, surgical lamp as a light source and a …