Search results for "Plethysmograph"
showing 10 items of 94 documents
Reliability of Short-Term Heart Rate Variability Indexes Assessed through Photoplethysmography
2018
The gold standard method to monitor heart rate variability (HRV) comprises measuring the time series of interbeat interval durations from electrocardiographic (ECG) recordings. However, due to the widespread use, simplicity and usability of photoplethysmographic (PPG) techniques, monitoring pulse rate variability (PRV) from pulse wave recordings has become a viable alternative to standard HRV analysis. The present study investigates the accuracy of PRV, measured as a surrogate of HRV, for the quantification of descriptive indexes computed in the time domain (mean, variance), frequency domain (low-to-high frequency power ratio LF/HF, HF band central frequency) and information domain (entropy…
Validity of the Wrist-Worn Polar Vantage V2 to Measure Heart Rate and Heart Rate Variability at Rest
2021
Heart rate (HR) and heart rate variability (HRV) can be monitored with wearable devices throughout the day. Resting HRV in particular, reflecting cardiac parasympathetic activity, has been proposed to be a useful marker in the monitoring of health and recovery from training. This study examined the validity of the wrist-based photoplethysmography (PPG) method to measure HR and HRV at rest. Recreationally endurance-trained participants recorded pulse-to-pulse (PP) and RR intervals simultaneously with a PPG-based watch and reference heart rate sensor (HRS) at a laboratory in a supine position (n = 39; 5-min recording) and at home during sleep (n = 29; 4-h recording). In addition, analyses wer…
Impact of a maternal high fat high sucrose diet on progeny's olfactory system
2018
International audience
Toward the development of a remote photoplethysmographic sensor
2019
Heart-rate estimation performed with remote photoplethysmography is a very active research field. Since pioneer works in 2010, which demonstrated the feasibility of the measure with low-grade consumers’ camera (webcam), the number of scientific publications have increased significantly in the domain. Hence, we observe a multiplication of the methods in order to retrieve the photoplethysmographic signal which hasled to an increased precision and quality of the heartrate estimation. Region of interest segmentation is a key step of the processing pipeline in order to maximize the quality of the measured signal. We propose a new method to perform remote photoplethysmographic measurement using a…
Optimal Source Selection for Image Photoplethysmography
2016
International audience; This paper presents an optimal selection on the region of interest (ROI) and color spaces to extract photoplethysmography signals from facial videos. The study is carried out under two sections; ROI selection and color space selection. We compared five different ROI selection for different regions of the face. We also investigated three color spectrums namely additive, perceptual and orthogonal color spaces. The study experimented on the publicly available human-computer interaction (HCI) database. When evaluated on 30 subjects, the results showed that the ROI selection on the forehead and the green spectrum of the additive color space to provides higher accuracy for…
Mutes gļotādas mikrocirkulācijas novērtējums izmantojot attēlvides fotopletizmogrāfiju
2019
Manipulācijas ar smaganām ir kļuvušas par standarta procedūrām zobārstniecībā rosinot nepieciešamību pēc smaganu funkcionālām izvērtēšanas metodēm. It īpaši tādēļ, ka smaganu klīniskā aina nevienmēr atspoguļo to funkcionālo stāvokli un morfoloģiskās īpatnības var nomaskēt funkcionālos traucējumus. Vietējā anestēzija ir neatņemama zobārstniecības procedūra, kas novērš pacienta diskomfortu manipulāciju laikā, taču dažreiz tā var radīt arī nevēlamās blakusparādības vai pat komplikācijas, kam ir vairāki iemesli (lielās devas, individuālā jutība uz kādu no anestēzijas komponentu, traucējumi pulpas un smaganu asins apgādē, vai pat neirotoksicitāte). Līdz ar to devas samazināšana ir ļoti svarīga, …
Optisko metožu un ierīču izstrāde kardiovaskulārā stāvokļa kontrolei reālā laikā
2013
Elektroniskā versija nesatur pielikumus
Quantification of intracranial contribution to rheoencephalography by a numerical model of the head
2000
Abstract Objectives : Partial contributions of intracranial and extracranial circulation to rheoencephalography (REG) remain uncertain. The main goal of this work is to determine theoretically the capability of REG techniques to reflect intracranial blood flow. Methods : Head and current injection electrodes were computationally modeled to assess REG sensitivity to brain and scalp conductivity changes. Data obtained were related to tissue perfusions to calculate the partial contribution of cerebral blood perfusion to REG I, REG II and monopolar REG and to assess their amplitudes. Results : When REG I and monopolar REG were used, the theoretical maximum of intracranial contribution was reach…
Clinical evaluation of automated capillary refill time estimation in dogs and cats
2019
In this study, we clinically evaluated a pulse oximeter-based device for automated capillary refill time (CRT) estimation in dogs and cats. CRT can reveal conditions like shock or anemia in dogs and cats. However, visual CRT estimation has low repeatability, and the available optical systems for automated estimation are not suitable for pets. We evaluated a custom-made portable CRT measuring device on various measurement sites of 12 dogs and 11 cats with parallel visual CRT estimation on the gum by treating veterinarian. The capillary refill was also recorded by a video camera for reference. The visual and video procedures were moderately correlated with the coefficient of 0.61; visual CRT …
A portable multisensor system to assess cardiorespiratory interactions through photoplethysmography
2022
Nowadays, the ever-growing interest to health and quality of life of individuals and the advancements in electronic devices technology are pushing the development of portable and wearable biomedical devices able to pursue a minimally invasive monitoring of physiological parameters in daily-life conditions. Such devices can now carry out a real-time assessment of the subjects’ overall health status and possibly even detect ongoing diseases. In this context, we have designed and implemented a multisensor portable system able to perform synchronous real-time acquisitions of electrocardiographic (ECG), photoplethysmographic (PPG) and airflow breathing signals. We investigated cardiorespiratory …