Search results for "Biomedical engineering"

Selected peptides targeted to the NMDA receptor channel protect neurons from excitotoxic death

1998

Excitotoxic neuronal death, associated with neurodegeneration and stroke, is triggered primarily by massive Ca2+ influx arising from overactivation of glutamate receptor channels of the N-methyl-D-aspartate (NMDA) subtype. To search for channel blockers, synthetic combinatorial libraries were assayed for block of agonist-evoked currents by the human NR1-NR2A NMDA receptor subunits expressed in amphibian oocytes. A set of arginine-rich hexapeptides selectively blocked the NMDA receptor channel with IC50 approximately 100 nM, a potency similar to clinically tolerated blockers such as memantine, and only marginally blocked on non-NMDA glutamate receptors. These peptides prevent neuronal cell d…

Recurrence quantification analysis as a tool for complex fractionated atrial electrogram discrimination

2012

International audience; Atrial fibrillation is the most encountered pathology of the heart rate. The reasons of its occurrence and its particular characteristics remain unknown, resulting from complex phenomena interaction. From these interactions emerges Complex Fractionated Atrial Electrograms (CFAE) which are useful for the ablation procedure. This study presents a method based on nonlinear data analysis, the Recurrence Quantification Analysis (RQA) applied on intracardiac atrial electrograms to detect CFAE particularities. The results obtained on areas previously tagged by a cardilogist show a good sensitivity to CFAE. Combination of RQA features offers a larger discrimination potential…

Reaching and Grasping a Glass of Water by Locked-In ALS Patients through a BCI-Controlled Humanoid Robot

2017

Locked-in Amyotrophic Lateral Sclerosis (ALS) patients are fully dependent on caregivers for any daily need. At this stage, basic communication and environmental control may not be possible even with commonly used augmentative and alternative communication devices. Brain Computer Interface (BCI) technology allows users to modulate brain activity for communication and control of machines and devices, without requiring a motor control. In the last several years, numerous articles have described how persons with ALS could effectively use BCIs for different goals, usually spelling. In the present study, locked-in ALS patients used a BCI system to directly control the humanoid robot NAO (Aldebar…

The significance of the triceps surae muscle action as a determinant in the biomechanical genesis of ski fall injuries

1985

In an epidemiologic study of 700 ski fall injuries YOUNG /1/ established a classification of the different fall modes involved. In more than 60 % of all falls that lead to an injury he found a forward bending motion of the body which is frequently coupled with a twisting of the body around the lower extremity. This clearly shows the importance of the forward motion component of the skier’s body in ski fall traumatology. The type of injury and its location depend on the action of the ski binding system. If the binding does not release in a ski fall, the fraction of injuries in the lower extremity amounts to nearly 100 %. If the binding does release, however, the injuries ocurring in this cas…

Electrohysterogram Signals from Patients with Threatened Preterm Labor: Concentric Ring Electrode Vs Disk Electrode Recordings

2017

Time-frequency analysis for early classification of persistent and long-standing persistent atrial fibrillation

2016

This study aimed to assess an early classification of persistent and long-standing persistent atrial fibrillation patients by means of the time-frequency analysis of the surface ECG, which would allow electrophysiologists to choose the most suitable therapeutic approach to treat this arrhythmia. 140 consecutive unselected patients suffering from atrial fibrillation conformed the study population (84 persistent and 56 long-standing persistent). After ventricular activity cancellation, time-frequency analysis of the atrial activity was performed. Then, the study of phase variations along time for those frequency bands where the average power of atrial activity is concentrated, together with t…

Effectiveness of tailored exercise therapy in patients with knee osteoarthritis and comorbidity: a randomized controlled trial

2016

Stratified exercise therapy by physical therapists in primary care is feasible in patients with knee osteoarthritis

2018

Background There is strong evidence that exercise therapy is effective in reducing pain and activity limitations in knee osteoarthritis (OA), but effect sizes are low to moderate. Stratified exercise therapy tailored to clinically relevant subgroups of patients is expected to optimise treatment effects in a cost-effective manner. Objectives This study aimed to explore the feasibility of a newly developed model of stratified exercise therapy in primary care. Methods A mixed method design was used, consisting of an uncontrolled pretest-posttest design and a process evaluation. Eligible patients visiting a participating primary care physical therapist (PT) were included. Based on our model, pa…

Twitch interpolation during equal-intensity voluntary and electrically-evoked isometric contractions of the quadriceps muscle

2005

It has been suggested that, during contractions triggered by electrical stimulation, motor units are recruited in a reversed sequence compared to voluntary contraction. The classic view is that lar...

Dual channel photoplethysmography studies of cardio-vascular response to the body position changes

2005

The dual-channel photoplethysmography studies of physiological responses during 3-stage orthostatic test were performed. Clear differences in heartbeat rate, pulse wave transit time and blood pressure variations of healthy volunteers and diabetic patients have been observed.