Experimental investigation of pressure applied on the lower leg by elastic compression bandage

International audienceCompression therapy with stockings or bandage is the most common treatment for venous or lymphatic disorders. The objective of this study was to investigate the influence of bandage mechanical properties, application technique and subject morphology on the interface pressure, which is the key of this treatment. Bandage stretch and interface pressure measurements (between the bandage and theleg) were performed on 30 healthy subjects (15 men and 15 women) at two different heights on the lower leg and in two positions (supine and standing). Two bandages were applied with two application techniques by a single operator. The statistical analysis of the results revealed: no significant difference in pressure between men and women, except for the pressure variation between supine and standing position; a very strong correlation between pressure and bandage mechanical properties (p<0.00001) and between pressure and bandage overlapping (p<0.00001); a significant pressure increase from supine to standing positions (p<0.0001). Also, it showed that pressure tended to decrease when leg circumference increased. Overall, pressure applied by elastic compression bandages varies with subject morphology, bandage mechanical properties and application technique. A better knowledge of the impact of these parameters on the applied pressure may lead to a more effective treatment

Biomechanical analysis and modeling of lumbar belt: Preliminary study.

International audienceLow back pain is a major public health problem in European Countries. In France, about 50% of population is suffering of this pathology every year (Fassier 2011). Because of health care cost and sick leave (Fassier 2011; Leclerc et al. 2009), low back pain has both societal and economic adverse consequences. Many treatments are proposed. However no guideline is provided to physician. Treatment depends on patient, on low back pain type and evolution and also on physician knowledge and believes. Medical devices, as lumbar belt might be proposed to treat low back pain. Several clinical trials have shown their efficacy (Calmels et al. 2009). Nevertheless, both mechanical and physiological effects of lumbar belts remain unclear. In this study, the application of a lumbar belt on the trunk is simulated by a finite element model. It is often assumed that the pain comes from the toe of the intervertebral discs and is related only to the intradiscal pressure and the thoracolumbar posture. Beside, abdominal pressure is used by belt manufacturers as a marker of the lumbar belt efficiency, because a change in the abdominal pressure could bring a change in the thoracolumbar posture and consequently on the intradiscal pressure. That's why the goal of this study is to determine the mechanical effect of wearing lumbar belt: i) on abdominal pressure; ii) on thoracolumbar posture; iii) on intervertebral disc pressure

BIOTEX-biosensing textiles for personalised healthcare management.

Textile-based sensors offer an unobtrusive method of continually monitoring physiological parameters during daily activities. Chemical analysis of body fluids, noninvasively, is a novel and exciting area of personalized wearable healthcare systems. BIOTEX was an EU-funded project that aimed to develop textile sensors to measure physiological parameters and the chemical composition of body fluids, with a particular interest in sweat. A wearable sensing system has been developed that integrates a textile-based fluid handling system for sample collection and transport with a number of sensors including sodium, conductivity, and pH sensors. Sensors for sweat rate, ECG, respiration, and blood oxygenation were also developed. For the first time, it has been possible to monitor a number of physiological parameters together with sweat composition in real time. This has been carried out via a network of wearable sensors distributed around the body of a subject user. This has huge implications for the field of sports and human performance and opens a whole new field of research in the clinical setting

Characterization of Fabric-to-Fabric Friction: Application to Medical Compression Bandages

Fabric-to-fabric friction is involved in the action mechanism of medical compression devices such as compression bandages or lumbar belts. To better understand the action of such devices, it is essential to characterize, in their use conditions (mainly pressure and stretch), the frictional properties of the fabrics they are composed of. A characterization method of fabric-to-fabric friction was developed. This method was based on the customization of the fourth instrument of the Kawabata Evaluation System, initially designed for fabric roughness and friction characterization. A friction contactor was developed so that the stretch of the fabric and the applied load can vary to replicate the use conditions. This methodology was implemented to measure the friction coefficient of several medical compression bandages. In the ranges of pressure and bandage stretch investigated in the study, bandage-to-bandage friction coefficient showed very little variation. This simple and reliable method, which was tested for commercially available medical compression bandages, could be used for other medical compression fabrics

Biomechanical caracterisation of lumbar belt by full-field techniques: Preliminary results

International audienceIn France, 50% of the population per year is suffering from low back pain. Lumbar belt are frequently proposed as a part of the treatment of this pathology. However mechanical ways of working of this medical device is not clearly understood, but abdominal pressure is often related. So an optical method was developed in this study to measure strain in lumbar belt and trunk interface and to derive a pressure estimation. Optical method consisted of coupling fringe projection and digital image correlation (DIC). Measurement has been carried out on the right side of a manikin wearing a lumbar belt. Average strain is 0.2 and average pressure is 1 kPa. Continuation of this study will be comparison of strain and pressure in different areas of lumbar belt (left side, front and back) and comparison of different lumbar belts. Results will be used in a finite elements model to determine lumbar belt impact in intern body. In long term, this kind of study will be done on human

Simulation of a low back pain treatment using a generic finite element model

International audienceEvery year, about 50% of French population is suffering of low back pain [Fassier, 2011]. A usual part of treatment is lumbar belt wearing. Nevertheless the biomechanical and physiological impacts are not clearly understood. In this study, the application of lumbar belt on the trunk is simulated by a finite element model. The objective of this model is to determine the impacts of wearing lumbar belt in abdominal pressure, spine posture and inter-vertebral disc pressure

Simulation of a low back pain treatment using a generic finite element model

International audienceEvery year, about 50% of French population is suffering of low back pain [Fassier, 2011]. A usual part of treatment is lumbar belt wearing. Nevertheless the biomechanical and physiological impacts are not clearly understood. In this study, the application of lumbar belt on the trunk is simulated by a finite element model. The objective of this model is to determine the impacts of wearing lumbar belt in abdominal pressure, spine posture and inter-vertebral disc pressure

Combined experimental and numerical approach for the assessment of pressure generated by elastic compression bandage

International audienceElastic compression bandage is a common treatment for venous or lymphatic disorders. Even though the efficacy of this treatment is admitted, its mechanism remains poorly understood. The success of the treatment depends on the applied pressure, which depends on the bandage tension and the curvature of the limb (Laplace’s Law), the number of layers of the bandage, its components (padding layer, crepe …) and elastic properties, and the interactions between bandages and leg. To better understand the action of compression bandage, many interface pressure measurements have been done, but those measurements only give local information and for now, the whole pressure distribution on the leg is not known. Also, due to complex leg curvature and to bandage-leg and bandage-bandage interactions, the Laplace’s law is not sufficient to give a fine description of the pressure fields. Some simulations of the leg compression exist. Most of them are modeling the action of a compression sock on a leg [1][2], whose mechanical properties are more or less complex [3]. As far as we know, the simulation of bandage application on the leg has never been done yet. The aim of this communication is to present a first numerical model of the action mechanisms of bandages onto the skin developed through an experimental-numerical approach. A subject-specific FE model of bandage application is developed and compared with experimental measurements on two subjects

Approche expérimentale et numérique pour l'étude de la pression d'interface appliquée par des bandages de compression

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Biomechanical analysis and modeling of lumbar belt: parametric study

International audienceLow back pain is a major public health problem in European Countries. In France, about 50% of population is suffering of this pathology every year [Fassier, 2011]. Because of health care cost and sick leave [Fassier, 2011], [Leclerc, 2009], low back pain as both societal and economic adverse consequences. Concerning medical devices, such as lumbar belts, several clinical trials have shown their efficiency [Calmels, 1999]. It might be essential to know which parameters are important so as to increase the efficiency of their medical effects on patients. Nevertheless, both mechanical and physiological effects of lumbar belts remain unclear.In this study, a parametrical method is used in order to identify which parameters are more important than others through numerical simulation. This study is indispensable to design lumbar belts