accepted for publication


Towards a Dynamic Tibial Component for Postoperative Fine-tuning Adjustment of Knee Ligament Imbalance


Andrea Collo, Shaban Almouahed, Chafiaa Hamitouche, Philippe Poignet, Eric Stindel

Accepted for Publication at:

BIODEVICES 2013 – 6th International Conference on Biomedical Electronics and Devices (conference official website)

Création d’un plan robotique

Assises de l’industrie 2012 :

Arnaud Montebourg parie sur le

secteur de la robotique

En ouverture de la 3e édition des Assises de l’Industrie consacrée aux “nouvelles frontières de l’industrie”, le ministre du Redressement productif a indiqué que ses équipes travaillaient sur un plan de soutien au secteur de la robotique, avec l’ambition d’en devenir un leader mondial.

Le ministre du redressement productif prononçait le matin du mercredi 17 octobre l’allocution d’ouverture des 3e Assises de l’industrie. A l’instar du plan de soutien au secteur automobile annoncé en juillet dernier, Arnaud Montebourg a indiqué que des dispositifs équivalents seront mis en place pour tous les secteurs, à commencer par celui de la robotique.

“Nous préparons un plan robotique. La France dispose dans ce domaine de compétences remarquables comparables à celles qui existent au Japon. Nous avons des inventeurs de génie mais, avec une atomisation des entreprises, les autres puissances, les autres Etats, viennent piocher dans ce secteur “, a précisé le ministre. Il a mis en avant l’objectif de s’imposer comme un leader dans ce domaine à l’échelle internationale.

Arnaud Montebourg n’a cependant pas précisé quand ce plan robotique serait mis en place“Nos équipes y travaillent”, a-t-il simplement déclaré. Quant à sa force de frappe, il a indiqué “une puissance modeste mais avec des effets décuplés”.

Le ministre a ensuite replacé ce plan dans un programme plus large et répété la volonté du gouvernement de faire son “travail de redémarrage, de mobilisation autour de l’industrie, en collaboration avec ses acteursC’est ce que j’appelle la politique du colbertisme participatif, on travaille ensemble pour reconstruire l’industrie en France”, a ajouté Arnaud Montebourg.

source: L’Usine Nouvelle

Patellar Reflex

definition _

Patellar Reflex, also called knee-jerk, is a stretch reflex associated with quadriceps femoris muscle stretching.

how it works _

The stretch is created by a blow upon the patellar tendon (positioned just below the Patella). This blow, usually performed with a specific tendon hammer, activates the muscle spindle in the quadriceps femoris muscle.

Muscle spindle is a particular type of sensory receptor, normally embedded in muscle fibers, able to detect changes in the length of the muscle itself. Once “activated” by the external blow, this receptor sends a signal to the spinal cord. Instead of involving higher nervous centres (it would take too long), at the level of the spinal cord an alpha-motor neuron is immediately activated.

The alpha-motor neuron conducts an efferent impulse directly back to the quadriceps femoris muscle, leading to its contraction. At the same time, an inhibitory interneuron relaxes the hamstring muscle, which is the quadricep’s antagonistic muscle.

The result of such coordinated contraction-relaxation, causes the “kick movement” of the leg. In normal health conditions, the leg extends once and then comes back to rest. It only takes about 50 milliseconds between the tap and the start of the leg kick.

why it is useful _

Patellar Reflex is a proprioceptive reflex which helps keeping posture and balance. The fact that everything “happens” at the level of the spinal cord, without involving higher nervous centres, allows for instance to keep balance without effort (actually, one does not have to focus on keeping an upright position). Energies are saved for more complex activities. Moreover, Patellar Reflex helps avoiding strong muscle contractions which could tear the tendon.

clinical interest _

As said, there is no interneuron in the pathway leading to contraction of the quadriceps muscle. Patellar Reflex can be used, for example, to check the conditions of the connections between the spinal cord and the muscles.

The absence or decrease of the Patellar Reflex is known as Westphal’s sign. On the other hand, multiple oscillation of the leg following the blow may be a symptom of cerebellar diseases.

source: contents taken from Wikipedia’s page

a nice video about mechanical mechanisms

Hi everybody! Just a simple post to share a nice video I found on youtube … 🙂

Last week I was surfing the web looking for potentially awesome ideas for my PhD project… well, actually I just needed a list of mechanical mechanisms and configurations in order to evaluate new design proposals for the knee prosthesis I am currently working on. As most of you will know, for sure, the step google research -> silly video is more or less immediate 😉

Most of the times the silly video you find has nothing to do with what you were looking for. Most of the times you watch it anyway, since “it only takes 2:35 minutes …”  🙂  and in this magic way, each day, dozens and dozens of hours are wasted by PhD students all over the world.

This time I was lucky! I found a very simple video, but actually it’s a really nice one! The user says it’s part of a “work by Ralph Steiner” … I don’t know anything about that, but the mechanisms that it shows are really amazing. Some of them have such strange shapes (I mean, the pieces that move are shaped in a bizarre way!) that you would bet the whole system won’t ever be able to move and next… the result is simply wonderful!

So simple + so strange = an amazing precise and regular motion!

Ah, by the way… finally the structure I adopted for my knee prosthesis is a particular screw-nut configuration 😉

Virtual Water

A very interesting web page created to sensibilize people on the problem of water consumption!

Most of the water we use – 92 % of it – is used in food production. Most of this water is managed by the world’s farmers. With the help of science and technology they have performed greater and greater miracles in improving water productivity – in getting more  crops per drop.


Of course yes… just click on the link below here (or on the image itself) to spend 3 minutes to learn something useful 😉

source: this website