Search results for "remote photoplethysmography"
showing 8 items of 8 documents
Comparison of region of interest segmentation methods for video-based heart rate measurements
2018
International audience; Conventional contact photoplethysmography (PPG) sensors are not suitable in situations of skin damage or when unconstrained movement is required. As a consequence, remote photoplethysmography (rPPG) has recently emerged because it provides remote physiological measurements without expensive hardware and improves comfort for long-term monitoring. RPPG estimation methods use the spatially averaged RGB values of pixels in a Region Of Interest (ROI) to generate a temporal RGB signal. The selection of ROI is a critical first step to obtain reliable pulse signals and must contain as many skin pixels as possible with a low percentage of non-skin pixels. In this paper, we ex…
Remote Photoplethysmography for Evaluation of Cutaneous Sensory Nerve Fiber Function
2021
About 2% of the world’s population suffers from small nerve fiber dysfunction, neuropathy, which can result in severe pain. This condition is caused by damage to the small nerve fibers and its assessment is challenging, due to the lack of simple and objective diagnostic techniques. The present study aimed to develop a contactless photoplethysmography system using simple instrumentation, for objective and non-invasive assessment of small cutaneous sensory nerve fiber function. The approach is based on the use of contactless photoplethysmography for the characterization of skin flowmotions and topical heating evoked vasomotor responses. The feasibility of the technique was evaluated on volunt…
Attālinātas fotopletizmogrāfijas metode femorāla nerva blokādes monitorēšanai
2020
Virsrakst: Attālinātas fotopletizmogrāfijas metode femorāla nerva blokādes monitorēšanai. Priekšvēsture: Attālināta fotopletizmogrāfija (aFPG) ir neinvazīva ādas mikrocirckulācijas izvērtēšanas metode, ko potenciāli var izmantot reģionālas anestēzijas sekmīguma pārbaudei. Viena no reģionālas anestēzijas problēmām ir vēlīnā un subjektīvā bloka iznākuma prognozēšana. Mērķis: Izvērtēt ādas mikrocirkulācijas izmaiņas ceļa locītavas ādā pēc prolongētas femorāla nerva blokādes ar aFPG metodi. Izvērtēt aFPG metodes efektivitāti diferencēšanā starp placebo un lokālo anestētiķu injekciju femorāla nerva blokādes laikā. Uzdevumi: 1. Izvērtēt aFPG spēju identificēt šļirci ar lokālo anestētiķi vai place…
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…
Semi-blind Source Extraction Methods: Application to the measurement of non-contact physiological signs
2018
Non-contact physiological measurements are highlydesirable in many biomedical fields such asdiagnosis of infants, geriartic patients, patients withextreme physical trauma, and fitness and well-being.Remote photoplethysmography is increasingly beingused for non-contact measurement of heart rate fromvideos which is one of the most common biomedicalproperty required for most medical diagnosis. Oneof the common techniques for performing remotephotoplethysmography involves using Blind SourceSeparation (BSS) methods to extract the cardiacsignal from video data.In this context, the objective of this thesis is todevelop different methods in the field of extractionand separation of sources by improv…
Gingivīta novērtēšana, izmantojot attālinātu fotopletismogrāfiju
2020
Pētījuma mērķis ir novērtēt smaganu perfūziju izmeklējamām personām izmantojot photopletizmogrāfijas metodi. Viens no pētījuma mērķiem bija reģistrēt kapsacīna izraisīto neiro-iekaisuma efektu. Metodoloģija Šķērsgriezuma pētījums, tika veikts iekļaujot nelielu izmeklējamo personu grupu , izmeklējamās personas pirms pētījuma veikšanas tika iepazīstinātas ar protokolu un rakstiski apstiprināja dalību pētījumā. Pētījuma gaitā smaganu perfūzijas tika reģistrēta miera apstākļos, un aplicējot uz smaganu virsmas kapsacīnu saturošu piparu ekstraktu, kas izraisīja pārejošu neirogēnu iekaisumu, ar tam raksturīgo hiperēmiju. Signāla reģistrācija tika veikta novietojot uz galvas izmeklējamai personai f…
Estimating Stress in Online Meetings by Remote Physiological Signal and Behavioral Features
2022
Work stress impacts people’s daily lives. Their well-being can be improved if the stress is monitored and addressed in time. Attaching physiological sensors are used for such stress monitoring and analysis. Such approach is feasible only when the person is physically presented. Due to the transfer of the life from offline to online, caused by the COVID-19 pandemic, remote stress measurement is of high importance. This study investigated the feasibility of estimating participants’ stress levels based on remote physiological signal features (rPPG) and behavioral features (facial expression and motion) obtained from facial videos recorded during online video meetings. Remote physiological sign…
Rubefacientu (mentola un niacīna) izraisīto mikrocirkulācijas reakciju novērtējums ādas dažādos dziļumos
2017
Ādai ir lokāla neiro-imuno-endokrīnā sistēma, kas lielā mērā atspoguļo organisma norises, kalpojot par sava veida „veselības indikatoru”. Īpaši pievilcīga un relatīvi pieejama ir ādas mikrocirkulācijas funkciju novērtēšana, ko var neinvazīvi veikt ar optiskām metodēm. Parasti praksē šādu reakciju novērtēšanai tiek lietoti standartizēti provokācijas testi, kā, piemēram, lokālas sildīšanas tests, vai acetilholīna jontoforēze. Taču bieži vien ādas sarežģītā mikrocirkulācija un liela regulācijas mehānismu daudzveidība apgrūtina rezultātu viennozīmīgu interpretāciju. Šajā kontekstā daudzsološa šķiet bispektrālā attēlveides fotopletizmogrāfija - optiska metode ar kuras palīdzību, izmantojot atšķi…