Results 201 to 210 of about 98,095 (251)

Pulsed Ultrasonic Transit Time Flowmeter

IRE Transactions on Bio-Medical Electronics, 1962
The difference in effective velocity of sound pulses propagated alternately upstream and downstream through moving blood is a measure of the blood velocity. A blood flowmeter based on this principle has been developed and employed in routine experiments over a period of four years.
D. L. Franklin, D. W. Baker, R. F. Rushmer   +2 more
openaire   +1 more source

Pulse wave transit time for monitoring respiration rate

Medical & Biological Engineering & Computing, 2006
In this study, we investigate the beat-to-beat respiratory fluctuations in pulse wave transit time (PTT) and its subcomponents, the cardiac pre-ejection period (PEP) and the vessel transit time (VTT) in ten healthy subjects. The three transit times were found to fluctuate in pace with respiration.
A, Johansson, C, Ahlstrom, T, Lanne, P, Ask   +3 more
openaire   +2 more sources

Pulmonary transit time has close relation with pulmonary pulse wave transit time in normal subjects

Clinical Physiology and Functional Imaging, 2022
AbstractBackgroundPulmonary transit time (PTT) and pulmonary pulse wave transit time (pPTT) are useful parameters for the evaluation of cardiopulmonary circulation and vascular alterations, but their relationship remains unknown. The aim of this study was to investigate the correlation between PTT and pPTT.MethodsA total of 60 healthy volunteers were ...
Jun Zhang, Xiao‐Zhi Zheng, Xu‐Chu Wu
openaire   +2 more sources

Videoplethysmographic Measurements of Pulse Wave Velocity and Pulse Transit Time

2020
Oxygen-rich blood has different absorption properties than de-oxygenated one. For that reason during the heartbeat there are slight changes in colour of human skin which are invisible to an eye but detectable for the colour video camera after applying motion picture processing algorithms.
Anna Pająk, Piotr Augustyniak
openaire   +1 more source

Transit-time considerations in short-pulse photoconductivity

Journal of Applied Physics, 1980
Little attention has been paid so far on the transit-time effects in the short-pulse photoconductivity. This paper discusses the effect of transit time on the time evolution of carriers in short-pulse photoconductivity. This is likely to effect the rise time of a fast-switching device.
V. K. Mathur, Chi H. Lee
openaire   +1 more source

Ultrasound for Venous Local Pulse Wave Velocity: Comparison of Pulse Transit Time Methods

2023 45th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 2023
Venous pulse wave velocity (vPWV) is a potential marker for determining the state of venous hemodynamics, venosclerosis, and vascular filling. Although there have been several studies on pulse wave velocity through blood vessels, the majority have focused on arteries, with only limited studies on veins.
Navya Rose, George, Rahul, Manoj, Raj Kiran, V, Nabeel, P M, Mohanasankar, Sivaprakasam, Jayaraj, Joseph   +5 more
openaire   +2 more sources

Unconstrained Pulse Transit Time Measurement System for Computer Users

2005 IEEE Engineering in Medicine and Biology 27th Annual Conference, 2005
Pulse Transit Time (PTT) is a simple non-invasive method to evaluate vascular function using photoplethysmography(PPG) and electrocardiography(ECG). This study introduces unconstrained PTT measurement method for computer users and evaluates that. The proposed system consists of chair and mouse those can measure ECG and PPG respectability.
Juwan, Park, Yongkyu, Lim, Youngjoon, Chee, Jungsoo, Kim, Kokeun, Kim, Kwang, Suk Park   +5 more
openaire   +2 more sources

Pulse Transit Time Measurement Using Bioimpedance

2019
Cardiovascular disease is a factor that leads to mortality in the populations of industrialized countries, being the large arteries pathology the main cause of morbidity and death from such disease. A functional characteristic of arteries that is changed under pathological conditions is their wall stiffness. Early diagnosis of such arterial alterations
Andrei L. A. Pires, Marcio N. Souza
openaire   +1 more source

Reproducibility of photoplethysmography-based local pulse transit time measurement

2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2017
There are several previously published approaches of measuring local pulse transit time (PTT). One of these approaches is to use two optical sensors based on photoplethysmography (PPG). However, little information about reproducibility in PPG based PTT measurement is available.
Beckmann, Nils, Viga, Reinhard, Dogangün, Aysegül, Grabmaier, Anton   +3 more
openaire   +2 more sources

Pulse Transit Time and Blood Pressure: An Intensive Analysis

Psychophysiology, 1983
ABSTRACTRelationships between pulse transit time (PTT) and intra‐arterial systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) were examined in 4 subjects under three conditions: rest, paced respiration, and mental arithmetic. PTT was measured from the EKG R‐wave to two peripheral pulses (brachial and radial) and from one pulse to ...
J D, Lane, L, Greenstadt, D, Shapiro, E, Rubinstein   +3 more
openaire   +2 more sources