Search results for " Stiffness"

Photoplethysmography Analysis of Artery Properties in Patients with Cardiovascular Diseases

2008

In this study arterial parameters of healthy subjects were compared to those of patients with cardiovascular diseases. The photoplethysmography (PPG) measurements of blood volume pulsations have been performed. Using a novel algorithm for analysis of simultaneously measured ear and finger PPG signals, arterial parameters were evaluated in representative groups of healthy subjects and patients with cardiovascular diseases. Digital volume pulse (DVP), pulse cycle duration (T), augmentation index (AIx), reflection index (RI) and transit time of reflected wave (RTT) were evaluated in every heartbeat cycle. Correlations between the AIx and RI, T and RTT, AIx and standard deviation of AIx, RTT an…

Domains of Physical Activity in Relation to Stiffness Index in the General Population.

2021

Background Regular exercise training represents an important modifier of arterial stiffness (AS). Therefore, sex‐specific relations between domains of physical activity (PA; commuting, domestic, and leisure‐time PA, including active sport and occupational PA) with AS were investigated. Methods and Results Stiffness index by digital photoplethysmography was investigated in 12 650 subjects from the GHS (Gutenberg Health Study). Self‐reported PA was evaluated by the “Short Questionnaire to Assess Health‐Enhancing Physical Activity” and reported as activity score peer week, being a combined measure of duration, frequency, and intensity of PA. Multivariable linear regression analysis demonstrat…

Reply

2017

Serial combination of non-invasive tools improves the diagnostic accuracy of severe liver fibrosis in patients with NAFLD

2017

SummaryBackground The accuracy of available non-invasive tools for staging severe fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) is still limited. Aim To assess the diagnostic performance of paired or serial combination of non-invasive tools in NAFLD patients. Methods We analysed data from 741 patients with a histological diagnosis of NAFLD. The GGT/PLT, APRI, AST/ALT, BARD, FIB-4, and NAFLD Fibrosis Score (NFS) scores were calculated according to published algorithms. Liver stiffness measurement (LSM) was performed by FibroScan. Results LSM, NFS and FIB-4 were the best non-invasive tools for staging F3-F4 fibrosis (AUC 0.863, 0.774, and 0.792, respectively), with LSM ha…

Microvascular brain damage with aging and hypertension

2011

Loss of cognitive function and hypertension are two common conditions in the elderly and both significantly contribute to loss of personal independency. Microvascular brain damage - the result of age-associated alteration in large arteries and the progressive mismatch of their cross-talk with small cerebral arteries - represents a potent risk factor for cognitive decline and for the onset of dementia in older individuals. The present review discusses the complexity of factors linking large artery to microvascular brain disease and to cognitive decline and the evidence for possible clinical markers useful for prevention of this phenomenon. The possibility of dementia prevention by cardiovasc…

A long-term (two years) clinical trial with S-adenosylmethionine for the treatment of osteoarthritis

1987

In a long-term multicenter open trial involving 10 general practitioners, the efficacy and tolerance of S-adenosylmethionine (SAMe) were studied for 24 months in 108 patients with osteoarthritis of the knee, hip, and spine. At the end of the 24-month observation period, 97 of the patients were still in the study. The patients received 600 mg of SAMe daily (equivalent to three tablets of 200 mg each) for the first two weeks and thereafter 400 mg daily (equivalent to two tablets of 200 mg each) until the end of the 24th month of treatment. Separate evaluations were made for osteoarthritis of the knee, hip, cervical spine, and dorsal/lumbar spine. The severity of the clinical symptoms (morning…

Assessment of conduit artery vasomotion using photoplethysmography

2013

Vasomotion is a spontaneous oscillation of vascular tone. The phenomenon has been observed in small arterioles and capillaries as well as in the large conduit arteries. The layer of smooth muscle cells that surrounds a blood vessel can spontaneously and periodically change its tension and thereby the arterial wall stiffness also changes. As the understanding of the phenomenon is still rather obscure, researchers would benefit from a low-cost and reliable investigation technique such as photoplethysmography (PPG). PPG is an optical blood pulsation measurement technique that can offer substantial information about the arterial stiffness. The aims of this pilot study were to evaluate the usefu…

Numerical Treatment of the Filament-Based Lamellipodium Model (FBLM)

2017

We describe in this work the numerical treatment of the Filament-Based Lamellipodium Model (FBLM). This model is a two-phase two-dimensional continuum model, describing the dynamics of two interacting families of locally parallel F-actin filaments. It includes, among others, the bending stiffness of the filaments, adhesion to the substrate, and the cross-links connecting the two families. The numerical method proposed is a Finite Element Method (FEM) developed specifically for the needs of this problem. It is comprised of composite Lagrange–Hermite two-dimensional elements defined over a two-dimensional space. We present some elements of the FEM and emphasize in the numerical treatment of t…

Determinants of arterial stiffness in pre- and postmenopausal women

2013

Running in highly cushioned shoes increases leg stiffness and amplifies impact loading

2018

AbstractRunning shoe cushioning has become a standard method for managing impact loading and consequent injuries due to running. However, despite decades of shoe technology developments and the fact that shoes have become increasingly cushioned, aimed to ease the impact on runners’ legs, running injuries have not decreased. To better understand the shoe cushioning paradox, we examined impact loading and the spring-like mechanics of running in a conventional control running shoe and a highly cushioned maximalist shoe at two training speeds, 10 and 14.5 km/h. We found that highly cushioned maximalist shoes alter spring-like running mechanics and amplify rather than attenuate impact loading. T…