Search results for "Biome"

Information transfer and information modification to identify the structure of cardiovascular and cardiorespiratory networks

2017

To fully elucidate the complex physiological mechanisms underlying the short-term autonomic regulation of heart period (H), systolic and diastolic arterial pressure (S, D) and respiratory (R) variability, the joint dynamics of these variables need to be explored using multivariate time series analysis. This study proposes the utilization of information-theoretic measures to measure causal interactions between nodes of the cardiovascular/cardiorespiratory network and to assess the nature (synergistic or redundant) of these directed interactions. Indexes of information transfer and information modification are extracted from the H, S, D and R series measured from healthy subjects in a resting…

Canal transportation caused by a new instrumentation technique and three standard techniques

1996

The ability of three different enlarging techniques (balanced force concept, step-back, and recapitulation) and a prototype system to maintain the original canal path during root canal preparation were compared, in vitro, with a theoretical ideally prepared root canal. Measurements were made at the concave and convex sides of the canal at four different levels (1, 4, 5, and 7 mm from apical, respectively). Simulated root canals embedded in clear casting resin and an enlarging computer-supported device were used for this study. The results showed that none of the enlarging techniques used in this study was able to prepare a canal ideally. The prototype system, at level 1, showed an ideal amo…

Resonance frequency analysis-reliability in third generation instruments : Osstell mentor ®

2012

Few studies assess repeatability and reproducibility in registers of resonance frequency analysis (a value of dental implant stability). Objective: Few studies assess repeatability and reproducibility in resonance frequency analyses (implant stability evaluation). This study is aimed at assessing reliability (repeatabilty and reproducibility) in the Osstell Mentor® system using the intraclass correlation coefficient (ICC) as the statistical method. Study Design: ISQ measurements of RFA were carried out by means of the Osstell Mentor ® instrument in 58 implants in 19 patients. Six measurements were performed on each implant by means of two different Smart-Pegs (I and II). Three consecutive m…

A nonlinear biomechanical model for evaluation of cerebrospinal fluid shunt systems.

1994

In view of complications arising from physical properties of cerebrospinal fluid shunts, a biomechanical model of hydrocephalus was set up to study in vivo parameters that may influence their function. These include: intracranial pressure, compliance and pulses, intrathoracic, intra-abdominal, and subcutaneous pressures, and the effects of siphonage and repeated valve flushing. Each of these factors was studied separately upon shunt implantation in the model. Results of testing of a sample low-pressure valve with antisiphon device conformed with consumer information in regard to valve opening pressure and pressure flow measurements. No customer information, however, was supplied concerning …

Trunk kinematics during cross country sit-skiing ergometry: Skiing strategies associated to neuromusculoskeletal impairment

2016

Since trunk function plays a major role in propulsion in sit-skiers and athletes belonging to distinct classes have different abilities to control trunk muscles, the aim of this study is to evaluate how athletes personalized their skiing strategy to compensate their impairment and improve skiing effectiveness. Sixteen Paralympic sit-skiers belonging to different classes volunteered as participant. Each athlete executed two double poling tests on a ski ergometer at the maximal speed he/she can reach and the best, identified as the fastest, was considered in the analysis. A set of two passive reflective markers was used for kinematic analysis: the first marker was placed on the athlete should…

Assessment of paradoxical anterior translation in a CR total knee prosthesis coupling dynamic RSA and FE techniques

2021

Purpose: The study aims were to assess the kinematic data, Internal-External (IE) rotation, and Antero-Posterior (AP) translation of the contact points between the femoral condyles and polyethylene insert and to develop a combined dynamic RSA-FE (Radiostereometric – Finite Element) model that gives results congruent with the literature. Methods: A cohort of 15 patients who underwent cemented cruciate-retaining highly congruent mobile-bearing total knee arthroplasty were analyzed during a sit-to-stand motor task. The kinematical data from Dynamic RSA were used as input for a patient-specific FE model to calculate condylar contact points between the femoral component and polyethylene insert. …

Future perspectives in gastroenterology: laser.

1997

<title>Ultrasound detection of cavitation as a phenomenon common to intervention devices causing tissue ablation</title>

1992

Cavitation previously has been observed in association with ultrasonic angioplasty and high- frequency rotational atherectomy. This study evaluates the production of cavitation accompanying the use of several catheter-based devices under development or in current use in the practice of interventional cardiology. Catheters were examined in an in vitro model, and cavitation was evaluated using standard ultrasound imaging equipment. Cavitation was detected with each of the devices that effects tissue ablation, but not tissue resection. Devices produced characteristic patterns of cavitation dependent on the mode of energy release of the device. The size, but not the intensity, of the cavitation…

Trajectories of Physical Activity Predict the Onset of Depressive Symptoms but Not Their Progression: A Prospective Cohort Study

2016

This prospective, community-based study examined trajectories of physical activity from childhood to adulthood and whether these trajectories contributed to depressive symptoms in adulthood to a greater degree than adulthood physical activity. Participants (n=3596) were from the ongoing Cardiovascular Risk in Young Finns Study which started in 1980. Depressive symptoms were measured with Beck Depression Inventory (BDI-II) in 2012, and physical activity was assessed from 1980 to 2011 with self-reports. Analyses were adjusted for age, sex, childhood negative emotionality, socioeconomic factors, previous depressive symptoms, social support, body mass index, and smoking status (1980–2007). High…

Similar biomechanical properties of four tripled tendon graft models for ACL reconstruction

2021

Abstract Purpose The present study tested and compared the biomechanical properties of four different triplicate graft tendon techniques. Methods 32 tripled tendons from the common extensor muscle of bovine fingers were tested on a material testing machine, passing the end loop over a metal rod of a clevis connected to the load cell on the upper side, and fixing the lower end to a clamp. The samples were divided into four groups: (A) tripled with a free end sutured only to one of the two fixed bundles (B) tripled with a free end positioned between the two fixed strands and sutured to both (C) tripled with an S-shape and all the three strands sutured together at the upper and lower extremiti…