Traitement de la douleur | EPFL Graph Search

Le traitement de la douleur ou prise en charge de la douleur désigne une branche de la médecine qui utilise une approche multidisciplinaire pour atténuer la douleur et améliorer la vie de ceux qui vivent avec. L'équipe chargée du traitement inclut généralement des praticiens médicaux, des pharmaciens, des psychologues cliniques, des physiothérapeutes, des assistants médicaux et des infirmiers spécialistes clinique. L'équipe peut également inclure des spécialistes des maladies mentales ou encore des masseurs thérapeutiques. La douleur peut parfois disparaître rapidement une fois que la blessure ou le traumatisme sont guéris et traités par un praticien. Le traitement efficace de la douleur, sur le long terme, nécessite cependant les efforts coordonnés de l'équipe responsable. La médecine guérit les blessures et les maladies pour soutenir et accélérer la guérison, elle prend également en charge les symptômes comme la douleur lors du traitement et de la guérison. Quand une blessure résist

Studying the interactions between electro-magnetic elds and biological tissue

Laurine Kolly

Drug delivery systems (DDS) were engineered to overcome the drawbacks of more common methods such as oral pills and intravenous injections. Implantable capsules that release anesthetic drugs locally for pain management after Total Knee Arthroplasty (TKA) are currently in development within the LMIS1. The capsule will be implanted at the site of the wound during the operation and will be controlled wirelessly through resonant inductive coupling, enabling a local release of analgesics. Within this framework, this project aimed to investigate the interaction of electro-magnetic elds with the tissue that separates the transmitting coil of the controller from the implanted capsule. The main aspects that were studied consisted of the penetration of the magnetic eld and the Specic Absorption Rate (SAR). As the receiving coils on the reservoirs of capsule will each resonate at specic frequency between 300 MHz and 1.1 GHz, the aforementioned aspects were assessed at the two ends of the frequency spectrum. This was performed through the means of Finite Element Analysis, using COMSOL simulation software. To do so, models with three dierent types of media were built: air as a baseline, multi-layered tissue as an anatomically representative model, that reproduced remote power transfer to a capsule implanted at the level of the knee, and water as an approximation of the multi-layered tissue model. As a result, it appeared that, at the higher frequencies, the magnetic eld is subject to considerable attenuation, such that the power input necessary to generate sucient eld intensity at the level of the capsule in a multi-layered tissue model must be increased from a baseline of 5 W, to 10 W at 300 MHz and to 50 W at 1.1 GHz. The analysis of the SAR revealed that average peak SAR values reached are higher than the safety limit (in an uncontrolled environment) at a frequency of 1.1 GHz, and that the SAR is proportional to the power input. This implies that there is a trade-o to increasing the power input to adjust the intensity of the magnetic eld that could potentially be resolved by modifying the circuit design. Furthermore, it was concluded that approximating tissue with water may cause for the magnetic eld intensity as well as the SAR to be underestimated, due to the diering dielectric properties and to the density of water being lower than that of skin or tendon. Thus, a more anatomically accurate multi-layered tissue model should be favoured.

2020

Simulation of total ankle replacement using numerical modeling

Sara Molins Cabaní

The ankle is a complex joint of the human body which is most often affected by trauma. Osteoarthritis is a joint disease that can require surgical intervention and when it affects the ankle there are two options to achieve pain relief. For years ankle fusion has been the most common technique but it entails a huge reduction of the ankle joint. This last decades the trending to total ankle replacement (TAR) to deal with that disease has increased. However, the longterm results are far away from the success of other joint replacements like the knee or the hip. The complexity of the ankle joint makes difficult to predict and to know what causes the failure of the replacement. Therefore, a numerical model that includes mainly the bones of the ankle joint and the prosthetic elements is created. Then two different kind of prosthesis are compared using the same model. Finally, in order to test how the ankle acts for a daily life movement, another model performing a phase of the ascent of stairs cycle is created. This last model guides the movement by the contraction of the triceps surae muscle. Results show that the bone strain levels differ a lot depending on the geometry of the prosthesis tested being more recommendable the tibial implant that is designed with an horizontal keel because it leads to a more uniform distribution of the load. For all the simulations the tibia is the most affected bone and the strain results surpass the limit established in some cases. For the climbing stairs simulation none of the elements surpass the strain limits. Even so, the failure of the TAR may not be only related to the deformation of the bone as there are other non-prosthetic issues that can affect the success of it. This is the first time that a musculoskeletal model of the ankle has been developed in order to study a prosthetic joint. Even though improvements are needed to make the model more complete and reliable it has been shown that it is useful to obtain the behaviour of the joint and to assess different implant designs.

2012

Studying the interactions between electro-magnetic elds and biological tissue

Laurine Kolly

2020

Simulation of total ankle replacement using numerical modeling

Sara Molins Cabaní

2012