ITBM-RBM最新文献

The role of the Technological Innovation Center (TIC) in Garches hospital is to promote research and development of new technological aids and to follow developments in the field. This is done in co-operation with users, researchers, manufacturers and professionals in the field. Companies are supported to develop prototypes using new technologies to assist people with disabilities. The TIC carries out evaluations of different assistive technology products, from an ankle prosthesis to new kinds of wheelchairs. Numerous studies have been performed and finally have permitted to improve the usefulness of assistive technology for disabled people.

The choice of an ultrasound remain on medical, technical and budgetary criteria of an establishment. In a hospital configuration in constant change, the step will have to take into account as much as possible, increasingly bonded factors (medical interest, profitability, budgets restricted…), and to set up an acquisition policy of and ultrasound renewal. If clinical specificities and the machine's medical performances remain before the reference criteria in equipment acquisition process, the evolution towards the new hospitals funding methods (with the implementation of tariffing with the activity) imposes more and more the machine's activity like one of the dominating criteria choice process. Nevertheless the machine's activity although necessary, is not enough to operate a judicious choice. Taking charge of certain clinically necessary activities but not very productive is likely to be sacrificed in aid of the profit. In this work, we tried to arbitrate the choices by taking the medical needs and the financial constraints into account, due to the new fashion of financing of the hospital. The optimization of the ultrasounds park within the framework of the equipments renewal can and must integrate the two complementary aspects for a better choice.

Mechanobiological data from “in vivo”and “in vitro” studies attest that tissues modify their metabolism in relation to mechanical stress they experiment and its parameters. The central target of these modifications are local chimiomediators, which modulate contents of tissular biomaterials, specially collagen and proteoglycans, by regulating their synthesis and degradation by specific enzymes. Biomaterial histological organization is also affected.

Finally, these biochemical and histological modifications provide tissu with mechanical properties appropriate to in situ stress.

Man, who is composed of articulated segments, is constantly subjected to gravity in static equilibrium (posture) as in motion. The classical approach of biomechanics consists in describing intersegmentary tridimensional kinematics and the mechanical actions involved in motion. This article puts forward a more cross-disciplinary approach by describing as well: the interactions between mechanics and biochemistry, that is, the link existing between the constraints resulting from motion in the level of osteoligamentary structures and tissue metabolism; the interactions existing between mechanics and neurology, that is, the link between those same constraints in the level of mecanoreceptors and the neurological control of this motion.

The knee joint is composed of two articular systems: the femorotibial and femoropatellar joints. The femorotibial joint appears quite instable, with its two convexe femoral condyles on the planar tibial surface. Actually, a muscular and tendinous organization ensures stability during motion. The muscular extensor system, with quadriceps patella and patellar tendon, controls the forward sliding of the femoral condyles and provides the knee stability in the sagittal plane. The posterior internal/external capsular and muscular reinforcements, also called posterolateral/posteromedial corner, ensures stability during rotation in the frontal and horizontal planes. Nonetheless, it is necessary to add to this muscular organization, a powerful informative system where the cruciate ligaments of the knee assume the major role. Those ligaments still remain in tension and inform the nervous system in any motion of the knee. This functional organization allows both large flexion-extension and stability. This article shows as an example the functional organization of the femorotibial joint.

The article presents an innovative and original ergometer device allowing the characterization of the mechanical properties of skeletal muscles crossing a joint in terms of contractile and elastic properties. The different tests, which can be used, and the methods of quantification will be focused on the elastic properties. Research studies, which were conducted in different applications, will show the usefulness of such measurements, as well as, the interest of these measurements in clinical research, physical medicine and rehabilitation or sports application.

Cervical spine is certainly the most complex joint. Biomechanics behaviours of this segment coming from different authors are related in this article. Cervical spine can be divided in two parts: upper cervical spine from occiput to C2 and lower cervical spine from C3 to C7. In vitro biomechanical study shows a strongly non linear behaviour. 60% of the motion of the whole segment takes place at the upper cervical from occiput to C2. Coupling motions are significant, principally in lateral bending and axial rotation. On top of that authors describe a neutral zone with a very little stifness at the center of the behaviour graph. This area represents 60% of whole motion of each intervetebral joint. Finally, authors describe a loss of mobility of 40% with ageing. However weigth and size seem to be non significant on the mechanical behaviour of cervical spine.

The risks to be wounded when wearing heavy load are well-known. On the opposite, the sitting position, assimilated with the concept of rest and comfort, may appear riskless. However, the sitting position may generate musculoskeletal disorders. Recent studies in biomechanics make it possible to better understand the parameters of discomfort related to the sitting position. The articulations of the human body must respect physiological positions, allowing a muscular economic posture. The musculoskeletal disorders originate from an imbalance of the muscular tone. The muscular contractions, which are repeated or constant, even with a low amplitude, are harmful. This results into pain due to the spasms of the muscle. If the spinal curves are too much or too less accentuated in sitting position, or if the articulations of the body are in a position far from their neutral position, important stresses and strains are exerted on articular tissues. These strains will generate articular information responsible for the abnormal modification of tonicity. However, a posture, even if ideal, cannot be maintained during a too much time. This one will have noxious effects on the metabolism of articular tissues and on muscular fatigue. A relative mobility between certain parts of the seat may decrease these effects by supporting an alternation of strains on articular tissues. It is necessary to address the problems of seats' comfort by taking into account the morphological diversity of the users and while considering the biomechanical and mecanobiologic constraints.