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Light plethysmography

Eero Lauhkonen, Brendan G Cooper, Richard Iles
AIM: Structured light plethysmography (SLP) is a novel light-based method that captures chest wall movements to evaluate tidal breathing. We carried out a narrative mini-review of the clinical use of SLP in paediatrics. METHODS: PubMed and Google Scholar were searched for papers published in English up to December 2018. This identified a methodology paper published in 2010 and eight full papers, including three paediatric studies and one paediatric case report. We also included data from eight conference abstracts and one clinical case study...
March 1, 2019: Acta Paediatrica
Kristen Tgavalekos, Thao Pham, Nishanth Krishnamurthy, Angelo Sassaroli, Sergio Fantini
We report a study on twenty-two healthy human subjects of the dynamic relationship between cerebral hemoglobin concentration ([HbT]), measured with near-infrared spectroscopy (NIRS) in the prefrontal cortex, and systemic arterial blood pressure (ABP), measured with finger plethysmography. [HbT] is a measure of local cerebral blood volume (CBV). We induced hemodynamic oscillations at discrete frequencies in the range 0.04-0.20 Hz with cyclic inflation and deflation of pneumatic cuffs wrapped around the subject's thighs...
2019: PloS One
AbdelKebir Sabil, Jade Vanbuis, Guillaume Baffet, Mathieu Feuilloy, Marc Le Vaillant, Nicole Meslier, Frédéric Gagnadoux
Polysomnography (PSG) is necessary for the accurate estimation of total sleep time (TST) and the calculation of the apnea-hypopnea index (AHI). In type III home sleep apnea testing (HSAT), TST is overestimated because of the lack of electrophysiological sleep recordings. The aim of this study was to evaluate the accuracy and reliability of a novel automated sleep/wake scoring algorithm combining a single electroencephalogram (EEG) channel with actimetry and HSAT signals. The study included 160 patients investigated by PSG for suspected obstructive sleep apnea (OSA)...
November 26, 2018: Journal of Sleep Research
Valeriy V Zaytsev, Serguei V Miridonov, Oleg V Mamontov, Alexei A Kamshilin
Vasomotor reactivity, which is important to estimate neurogenic regulation of blood vessels in patients with different pathologies, is still assessed by occlusion plethysmography using sensors contacting the limbs. Recently we proposed a contactless approach for measuring blood flow changes during venous occlusion using imaging photoplethysmography [Kamshilin et al., Sci. Rep.7, 4642017]. In this work, the response of the vascular system on the occlusion was studied simultaneously by contact air-plethysmography system and remote optical system under illumination by incoherent polarized green light...
November 1, 2018: Biomedical Optics Express
Robert Lewis, Bryan T Hackfort, Harold D Schultz
Physiological systems often display 24 h rhythms that vary with the light/dark cycle. Disruption of circadian physiological rhythms have been linked to the progression of various cardiovascular diseases, and advances in the understanding of these rhythms have led to novel interventions and improved clinical outcomes. Although respiratory function has been known to vary between the light and dark periods, circadian rhythms in breathing have been understudied in clinical conditions. In the current study, we have begun to assess light/dark variations in respiration in chronic heart failure (CHF), a condition associated with abnormal resting and chemoreflex breathing as well as exercise intolerance...
2018: Advances in Experimental Medicine and Biology
Michael Ghijsen, Tyler B Rice, Bruce Yang, Sean M White, Bruce J Tromberg
In this work we introduce a modified form of laser speckle imaging (LSI) referred to as affixed transmission speckle analysis (ATSA) that uses a single coherent light source to probe two physiological signals: one related to pulsatile vascular expansion (classically known as the photoplethysmographic (PPG) waveform) and one related to pulsatile vascular blood flow (named here the speckle plethysmographic (SPG) waveform). The PPG signal is determined by recording intensity fluctuations, and the SPG signal is determined via the LSI dynamic light scattering technique...
August 1, 2018: Biomedical Optics Express
Michele Ghezzi, Laura Tenero, Michele Piazza, Marco Zaffanello, Giulia Paiola, Giorgio L Piacentini
BACKGROUND: Structured light plethysmography (SLP) is a new noninvasive technology to capture the movement of the thoracic and abdominal wall, and to assess some parameters indicative for lung function. OBJECTIVE: The purpose of the study was to evaluate the feasibility of SLP in children with asthma. METHODS: A total of 52 patients were enrolled: 25 with asthma exacerbation (group 1), 13 with well-controlled asthma (group 2), and 14 healthy controls (group 3)...
July 1, 2018: Allergy and Asthma Proceedings:
Zoltan Barth, Thomas Schwartz, Berit Flatø, Trond M Aaløkken, Akos Koller, May B Lund, Ivar Sjaastad, Helga Sanner
OBJECTIVE: To explore the associations between microvascular abnormalities assessed by nailfold capillaroscopy (NFC) and pulmonary and cardiac involvement in patients with juvenile dermatomyositis (DM) assessed after medium- to long-term follow-up. METHODS: Fifty-eight juvenile DM patients were examined mean 17.0 (SD 10.6) years after symptom onset. Nailfold capillary density (NCD) and neovascular pattern (defined as scleroderma active or late pattern) were analysed blinded to clinical data...
June 28, 2018: Arthritis Care & Research
Hamzah Hmeidi, Shayan Motamedi-Fakhr, Edward K Chadwick, Francis J Gilchrist, Warren Lenney, Richard Iles, Rachel C Wilson, John Alexander
Measurement of lung function can be difficult in young children. Structured light plethysmography (SLP) is a novel, noncontact method of measuring tidal breathing that monitors displacement of the thoraco-abdominal wall. SLP was used to compare breathing in children recovering from an acute exacerbation of asthma/wheeze and an age-matched cohort of controls. Children aged 2-12 years with acute asthma/wheeze (n = 39) underwent two 5-min SLP assessments, one before bronchodilator treatment and one after. SLP was performed once in controls (n = 54)...
June 2018: Physiological Reports
Lasse Gliemann, Stefan P Mortensen, Ylva Hellsten
Since the first measurements of limb blood flow at rest and during nerve stimulation were conducted in the late 1800s, a number of methods have been developed for the determination of limb and skeletal muscle blood flow in humans. The methods, which have been applied in the study of aspects such as blood flow regulation, oxygen uptake and metabolism, differ in terms of strengths and degree of limitations but most have advantages for specific settings. The purpose of this review is to describe the origin and the basic principles of the methods, important aspects and requirements of the procedures...
June 2018: European Journal of Applied Physiology
Alexia J Murphy-Alford, Melinda White, Liane Lockwood, Andrew Hallahan, Peter S W Davies
AIM: To describe the body composition, dietary intake and physical activity and of paediatric, adolescent and young adult childhood cancer survivors (CCS) and examine the factors that impact body composition after treatment. METHODS: This prospective cross-sectional study involved 74 subjects who were at least three years post treatment. Measurements included anthropometry, whole body potassium counting, air displacement plethysmography, and three day physical activity and diet diaries...
March 7, 2018: Clinical Nutrition: Official Journal of the European Society of Parenteral and Enteral Nutrition
Sakthi Kumar Arul Prakash, Conrad S Tucker
The authors of this work present a real-time measurement of heart rate across different lighting conditions and motion categories. This is an advancement over existing remote Photo Plethysmography (rPPG) methods that require a static, controlled environment for heart rate detection, making them impractical for real-world scenarios wherein a patient may be in motion, or remotely connected to a healthcare provider through telehealth technologies. The algorithm aims to minimize motion artifacts such as blurring and noise due to head movements (uniform, random) by employing i) a blur identification and denoising algorithm for each frame and ii) a bounded Kalman filter technique for motion estimation and feature tracking...
February 1, 2018: Biomedical Optics Express
Donald J Noble, William N Goolsby, Sandra M Garraway, Karmarcha K Martin, Shawn Hochman
In humans, exercises involving slowed respiratory rate (SRR) counter autonomic sympathetic bias and reduce responses to stressors, including in individuals with various degrees of autonomic dysfunction. In the rat, we examined whether operant conditioning could lead to reductions in respiratory rate (RR) and performed preliminary studies to assess whether conditioned SRR was sufficient to decrease physiological and behavioral responsiveness to stressors. RR was continuously monitored during 20 2-h sessions using whole body plethysmography...
2017: Frontiers in Physiology
Jose Medina-Inojosa, Virend Somers, Sarah Jenkins, Jennifer Zundel, Lynne Johnson, Chassidy Grimes, Francisco Lopez-Jimenez
INTRODUCTION: Estimating body fat content has shown to be a better predictor of adiposity-related cardiovascular risk than the commonly used body mass index (BMI). The white-light 3D body volume index (BVI) scanner is a non-invasive device normally used in the clothing industry to assess body shapes and sizes. We assessed the hypothesis that volume obtained by BVI is comparable to the volume obtained by air displacement plethysmography (Bod-Pod) and thus capable of assessing body fat mass using the bi-compartmental principles of body composition...
2017: Obesity, Open Access
Khongorzul Ganbold, Satoko Kakino, Hideharu Ikeda, Michiyo Miyashin
OBJECTIVES: To determine the pulp vitality after traumatic injury, dentists often use pulp sensitivity tests, which can be ambiguous in young permanent teeth with incomplete root formation. Transmitted-light plethysmography (TLP) is a non-invasive objective method that uses a 525-nm LED to detect blood volume change in the pulp. The present study aimed (1) to investigate pulpal blood flow with TLP and optical characteristics in healthy permanent maxillary incisors in different root formation stages, and (2) to assess the influences of body growth of the children and tooth color on the TLP amplitude...
November 2017: Archives of Oral Biology
Michele Ghezzi, Laura Tenero, Michele Piazza, Alessandro Bodini, Giorgio Piacentini
Structured Light Plethysmography (SLP) is a non-invasive method to study chest and abdominal movement during breathing and can identify abnormal contributions of the different regions of the chest. M.D hospitalized for pneumonia, underwent SLP and spirometry at admission (T0), after 48 hours (T1), and after one month (T2). SLP parameters showed expiratory flow limitation, information consistent with the spirometric parameters collected, and reduced motion in the area effected by pneumonia, with improvement and normalization at T1 and T2...
2017: Respiratory Medicine Case Reports
Marie-Cécile Niérat, Bruno-Pierre Dubé, Claudia Llontop, Agnès Bellocq, Lila Layachi Ben Mohamed, Isabelle Rivals, Christian Straus, Thomas Similowski, Pierantonio Laveneziana
The use of a mouthpiece to measure ventilatory flow with a pneumotachograph (PNT) introduces a major perturbation to breathing ("instrumental/observer effect") and suffices to modify the respiratory behavior. Structured light plethysmography (SLP) is a non-contact method of assessment of breathing pattern during tidal breathing. Firstly, we validated the SLP measurements by comparing timing components of the ventilatory pattern obtained by SLP vs. PNT under the same condition; secondly, we compared SLP to SLP+PNT measurements of breathing pattern to evaluate the disruption of breathing pattern and breathing variability in healthy and COPD subjects...
2017: Frontiers in Physiology
Marja H Leppänen, Pontus Henriksson, Christine Delisle Nyström, Hanna Henriksson, Francisco B Ortega, Jeremy Pomeroy, Jonatan R Ruiz, Cristina Cadenas-Sanchez, Marie Löf
PURPOSE: This study aimed to investigate longitudinal associations of objectively measured physical activity (PA) and sedentary behavior (SB) with body composition and physical fitness at a 12-month follow-up in healthy Swedish 4-yr-old children. METHODS: The data from the population-based MINISTOP trial were collected between 2014 and 2016, and this study included the 138 children who were in the control group. PA and SB were assessed using the wrist-worn ActiGraph (wGT3x-BT) accelerometer during seven 24-h periods and, subsequently, defined as SB, light-intensity PA, moderate-intensity PA, vigorous-intensity PA (VPA), and moderate-to-vigorous PA (MVPA)...
October 2017: Medicine and Science in Sports and Exercise
Z Helyes, Á Kemény, K Csekő, É Szőke, K Elekes, M Mester, K Sándor, A Perkecz, L Kereskai, L Márk, Á Bona, A Benkő, E Pintér, J Szolcsányi, C Ledent, B Sperlágh, T F Molnár
Sporadic clinical reports suggested that marijuana smoking induces spontaneous pneumothorax, but no animal models were available to validate these observations and to study the underlying mechanisms. Therefore, we performed a systematic study in CD1 mice as a predictive animal model and assessed the pathophysiological alterations in response to 4-mo-long whole body marijuana smoke with integrative methodologies in comparison with tobacco smoke. Bronchial responsiveness was measured with unrestrained whole body plethysmography, cell profile in the bronchoalveolar lavage fluid with flow cytometry, myeloperoxidase activity with spectrophotometry, inflammatory cytokines with ELISA, and histopathological alterations with light microscopy...
August 1, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
Alexei A Kamshilin, Valeriy V Zaytsev, Oleg V Mamontov
Occlusion plethysmography is an important method for assessment of the status of the cardiovascular system, which provides valuable information concerning arterial and venous blood flow, including mechanisms of their regulation. All up-to-date systems estimate change of the limb's volume during occlusion by contact-type sensors. The objective of the research is demonstration of feasibility of the novel approach to measuring the blood flow during venous occlusion by using imaging photoplethysmography (PPG). Twenty healthy individuals participated in the experiment...
March 28, 2017: Scientific Reports
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