Une prothèse de genou connectée

source: cet article du Télégramme

on récolte ce que l’on sème: celui ci, celui là

Un projet de prothèse de genou connectée porté par une équipe brestoise vient de décrocher une subvention nationale de 7,9 M€. Des capteurs signaleront une infection ou un défaut mécanique de la prothèse.

Le budget total de notre projet FollowKnee est de 24 M€, il nous fallait trouver les deux tiers du financement, l’Agence nationale de recherche nous apporte 7,9 M€. L’originalité de cet appel à projets pour la recherche hospitalo-universitaire en santé est d’associer obligatoirement la recherche, la médecine et les entreprises. L’objectif est d’arriver, au bout de cinq ans, à un produit commercialisable avec une évaluation clinique des résultats“, explique le Pr Eric Stindel, directeur du Laboratoire de traitement de l’information médicale (LaTIM) unité Inserm 1101, porteur du projet.

L’enjeu est d’importance, la pose de prothèse de genou a progressé de plus de 600 % en 20 ans et cela va continuer. L’an passé, en France, un peu moins de 80.000 prothèses de genou ont été posées, contre 150.000 prothèses de hanche. “Cette progression est due au fait que les patients jeunes ne veulent plus rester souffrir. Ils savent que les prothèses fonctionnent et vont leur permettre de refaire du sport, de la course ou du golf. De plus, l’épidémie d’obésité aggrave aussi les problèmes d’arthrose des genoux. Un kilo de plus sur la balance représente plusieurs kilos de contrainte sur un genou et une usure plus rapide“.

Des capteurs intégrés à la prothèse vont être développés par le Commissariat à l’énergie atomique (CEA) de Grenoble, l’un des trois partenaires industriels. Ces capteurs vont suivre le fonctionnement mécanique, vérifier si le genou plie bien et détecter le plus tôt possible des signes d’infection par la mesure de la température et du pH (NDLR mesure de l’acidité).

L’échec de la pose d’une prothèse est lié soit à un descellement de l’os en raison de contraintes particulières, soit à une infection“, précise le Pr Eric Stindel, qui pilote par ailleurs le centre de référence en infections ostéo-articulaires complexes de Brest. Le patient pourra récupérer, dans son smartphone par exemple, des informations sur sa prothèse et le rééducateur adaptera ses exercices.

imascap

En cas de signaux d’infection, le patient entrera rapidement dans une filière de dépistage. Le suivi sera plus personnalisé. Le premier partenaire industriel du projet est la société Imascap, start-up brestoise créée par un doctorant du LaTIM en 2009 qui va commercialiser le produit.

L’innovation de ce projet réside aussi dans la technique de fabrication de cette prothèse, grâce à une imprimante 3D et aux images d’un scanner. Ce sera le travail de la société SLS, en Ille-et-Vilaine, spécialisée dans les implants dentaires, qui va se diversifier dans la prothèse orthopédique à partir d’un alliage de métal et de céramique. Le troisième partenaire industriel est Immersion, une société bordelaise leader français de la réalité augmentée, qui va créer des outils d’aide à la pose de cette prothèse. Les autres partenaires du projet sont l’Insitut de recherche technologique (IRT Bcom), qui a un site brestois, et le CHRU de Brest, qui a financé le montage du projet. “En sortie, il y aura au moins une quinzaine d’emplois à la clef en tout chez nos partenaires industriels. C’est un projet à coeur breton, une vraie reconnaissance, à la fois, pour les équipes de recherche et pour les industriels qui en sont issus comme Imascap“, conclut le Pr Stindel.

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Comment rééquilibrer les ligaments du genou sans ré-opérer un patient ?

Un nouveau volet de Demain Chez Vous a été publié! Après le premier épisode, c’est au tour de mon projet de thèse 🙂

L’arthrose conduit à la pose de près de 70 000 prothèses du genou par an en France. Au fil du temps, la prothèse subit l’évolution des modes de vie du patient ce qui peut conduire au descellement de la prothèse ou à déséquilibrage des ligaments. Il est alors nécessaire de procéder à une chirurgie dite de reprise. Pour pallier ce problème une nouvelle génération d’implants orthopédiques instrumentés est en cours de développement à Télécom Bretagne. Le médecin pourra corriger la tension des ligaments en actionnant le système placé dans la prothèse.
Ce dispositif innovant et prometteur est développé à Télécom Bretagne au Latim, sous la responsabilité de Chafiaa Hamitouche.

Squat movements: some hints

source: this website

The squat movement can be described as a compound exercise which involves multiple groups of muscles. It is usually performed by recreational and professional athletes to strengthen hip, knee and ankle muscles. The squat exercise consists of two main phases, lowering and standing.

The lowering phase

The body starts from a standing position and, replicating the motion performed while sitting on a chair, it is lowered until the squat configuration is achieved. All the lower limb joints are involved, with several groups of muscles that contract as they lengthen. This results in eccentric contractions.squatL

  • Hip: flexion movement. The hip extensors (gluteus maximus, semimembranosus, semitendinosis and biceps femoris) mainly control the speed of the body, whose lowering is naturally supported by gravity.
  • Knee: flexion movement. The knee extensors (rectus femoris, vastus medialis, vastus intermedius and vastus lateralis) mainly allow to tune the knee bending speed.
  • Ankle: dorsiflexion movement. The plantarflexor muscles (gastrocnemius and soleus) mainly counteract the pull of gravity and provide a stable support on the ground.
The standing phase

squatSThe body leaves the squat configuration and returns to an upright position. The speed of this movement is continuously controlled, as well as the stable support provided by the feet. Once again, this is ensured by the combined action of all the lower limb joints. The same groups of muscles as for the lowering phase now shorten as they contract. This produces concentric contractions.

  • Hip: extension movement. The hip extensors mainly bring the trunk back to an upright position.
  • Knee: extension movement. The knee extensors help contracting and smoothly straightening the knee joints.
  • Ankle: plantarflexion movement. The plantarflexor muscles push down against the ground and are responsible for the overall stability of the body.

 

the chairless chair by Noonee

source: L. Seward’s post on this website

Coming out of NCCR Robotics lab, the Bio-Inspired Robotics laboratory at University of Cambridge (previously at ETH Zurich, Switzerland), Noonee® is a revolutionary start-up business aiming to solve healthcare problems within the manufacturing industry. The idea is to provide an exoskeleton that supports the weight of the user only when they feel tired , rather than continuously taking on this weight – meaning that the wearer is using their muscles and actively, rather than passively, sitting.

P8iHDpcWithin the manufacturing industry, keeping employees healthy has been a major concern and challenge for many companies around the world for a long time. Jobs often involve spending long periods of time bending and crouching and as a result can leave staff with substantial back and knee problems. Of 215 million industry sector workers in the EU, a staggering 85 million are reported to suffer from muscle related disorders. Market solutions that are currently available may also pose problems as they limit short term tiredness by taking all the weight of the user, which can lead to muscle weakening. What is needed is a product that can support staff working on production lines while keeping them healthy. The “chair” is not a chair as we know it, but more of an exoskeleton for the legs with a belt to attach it to the hips and straps that wrap around the thighs. The slim structure has joints that allow the wearer to move freely, but when the wearer is in a position they wish to stay in for a long time (e.g. crouching under a car on a production line), this position can be fixed, meaning that the wearer does not need to use the same muscle groups for long periods of time to hold the position. The advantage of such a structure is that it can be worn anywhere and can also be used when standing and walking. This reduces the space required as compared to a traditional chair and reduces the hassle when compared to other solutions, such as chairs that are strapped to the user.

imageThe Chairless Chair® is currently still in prototype and the current version requires the user to fix a position by crouching down into the required position and pushing a button. It is hoped that future iterations of the Chairless Chair® will be actuated to allow the system to become intelligent and understand the intention of the user, allowing it to be fixed into position without any additional input from the wearer.

all’IIT si stampano cartilagini!

da quest’articolo de La Repubblica dell’11/10/15

L’intuizione del genovese Luca Coluccino: togliere la “memoria” al tessuto e riprodurlo

L’idea gli è venuta a Pittsburgh — la città della Pennsylvania famosa per Flashdance e le antiche industrie dell’acciaio — ma continuerà a svilupparla sulla collina di Morego, a Genova, nell’Istituto Italiano di Tecnologia. Luca Coluccino ha 28 anni, una laurea in ingegneria biomedica e una passione per le articolazioni delle ginocchia. Lo si capisce dalla tesi di laurea e dal suo dottorato di ricerca al’IIT, dove dal 2013 studia come ricostruire e riparare le cartilagini.

084139429-51f017df-9dea-4c3a-95e2-cc1e89146d41Lo scorso anno, durante un periodo all’Università di Pittsburgh, Luca ha azzardato: “Ma perché invece di fare protesi sintetiche non proviamo a creare una cartilagine vera? Una cartilagine senza parti artificiali. Biologica, umana. E poi usiamo questo tessuto senza forma come “inchiostro” per una stampante in 3D“. Era un’idea un po’ folle: creare la cartilagine è l’ambizione dei gruppi di ricerca più avanzati del mondo, dalla Corea del Sud agli Stati Uniti. Ci provano da anni, senza successo. Ma Luca e il team con cui lavora — il gruppo Smart Materials del Dipartimento di Nanofisica dell’IIT — ci sono riusciti. E a metà settembre hanno spiegato come fare al TERMIS di Boston, la conferenza mondiale di riferimento per la medicina rigenerativa.

Luca arriva all’IIT con un maggiolone anni ’70, la giacca stilosa e una barbetta bionda accennata. A parlar di cartilagini gli si illuminano gli occhi. “Sono affascinanti perché non si ricreano come le ossa — spiega — Se un adulto ha una lesione grave a una cartilagine bisogna sostituirla con protesi metalliche o plastiche. Ma sono parti estranee al corpo umano: causano problemi di rigetto e non durano all’infinito“. Tra qualche anno potrebbe non essere più così, perché il team dell’IIT in collaborazione con l’Università di Pittsburgh (dove Coluccino era sotto la guida di un altro genovese, il ricercatore Riccardo Gottardi) ha trovato la “ricetta” per ricostruire cartilagini, tendini e menischi. Ad ascoltare Luca Coluccino sembra semplice: si tratta chimicamente una cartilagine, per esempio, sino a farla diventare un liquido che ha perso tutte le informazioni che nel corpo di un’altra persona potrebbero dare reazione immunitaria. “Solo una cosa le deve rimanere: la ‘memoria’ di essere una cartilagine“, avverte Coluccino.

Prosthetic Knee Systems Overview

source: Bill Dupes’s original post published on this website

OF ALL PROSTHETIC COMPONENTS, THE KNEE SYSTEM IS ARGUABLY THE MOST COMPLEX. IT MUST PROVIDE RELIABLE SUPPORT WHEN STANDING, ALLOW SMOOTH, CONTROLLED MOTION WHEN WALKING, AND PERMIT UNRESTRICTED MOVEMENT FOR SITTING, BENDING AND KNEELING.

Prosthetic knees have evolved greatly over time, from the simple pendulum of the 1600s to those regulated by rubber knees01bands and springs or pneumatic or hydraulic components. Now, some knee units have advanced motion control modulated through microprocessors. For the transfemoral (above-knee, including hip and knee disarticulation) amputee, successful function depends on selecting the correct knee to fit the person’s age, health, activity level and lifestyle. The latest or advanced knee is not necessarily the best choice for everyone. For some amputees, safety and stability are more important than functional performance. Active amputees, on the other hand, prefer a knee that will give them a higher level of function even if it requires greater control.

Given the wide variety of choices and consumer needs, prosthetists and rehabilitation specialists can help amputees choose the best prosthetic knees for their individual requirements. They can also teach amputees how to use their new knees properly, which is critical for avoiding discomfort, stumbling and falling. A key way to evaluate an individual’s prosthetic needs is to observe his or her walking cycle, which can be divided into two parts: the “stance phase” (when the leg is on the ground supporting the body) and the “swing phase” (when the leg is off the ground, also referred to as “extension”). The happy medium between these two extremes (stance, or stability, versus ease of swing, or flexion) is different for each individual.

Although over 100 individual knee mechanisms are commercially available, they can be divided into two major classifications: mechanical and computerized. Mechanical knees can be further separated into two groups: single-axis knees and polycentric, or multiaxis, knees. All knee units, regardless of their level of complexity, require additional mechanisms for stability (manual or weight-activated locking systems) and additional mechanisms for control of motion (constant or variable friction and “fluid” pneumatic or hydraulic control).

Single-Axis Vs. Polycentric Knees

The single-axis knee, essentially a simple hinge, is generally considered the “workhorse” of the basic knee classes due to its knees02relative simplicity, which makes it the most economical, most durable, and lightest option available. Single-axis knees do have limitations, however. By virtue of their simplicity, amputees must use their own muscle power to keep them stable when standing. To compensate for this, the single-axis knee often incorporates a constant friction control and a manual lock. The friction keeps the leg from swinging forward too quickly as it swings through to the next step.

knees03Polycentric knees, also referred to as “fourbar” knees, are more complex in design and have multiple axes of rotation. Their versatility is the primary reason for their popularity. They can be set up to be very stable during early stance phase, yet easy to bend to initiate the swing phase or to sit down. Another popular feature of the knee’s design is that the leg’s overall length shortens when a step is initiated, reducing the risk of stumbling. Polycentric knees are suitable for a wide range of amputees. Various versions are ideal for amputees who can’t walk securely with other knees, have knee disarticulation or bilateral leg amputations, or have long residual limbs. A standard polycentric knee has a simple mechanical swing control that provides an optimal single walking speed; however, many polycentric knees incorporate fluid (pneumatic or hydraulic) swing control to permit variable walking speeds. The most common limitation of the polycentric design is that the range of motion about the knee may be restricted to some degree, though usually not enough to pose a significant problem. Polycentric knees are also heavier and contain parts that may need to be serviced or replaced more often than those of other types of prosthetic knees.

Microprocessor Knees

Microprocessor knees are a relatively new development in prosthetic technology. Onboard sensors detect movement and timing and then knees04adjust a fluid /air control cylinder accordingly. These microprocessor-controlled knees lower the amount of effort amputees must use to control their timing, resulting in a more natural gait. In spite of all of the amazing inventions and constant tweaks and improvements, the perfect prosthetic knee has yet to be invented; otherwise, there wouldn’t be over 100 different designs on the market. As advanced as the technology seems today compared to the earliest designs of the 1600s, one can only imagine the developments that will eventually result as researchers further explore the potential of mechanical, hydraulic, computerized and “bionic,” or neuroprosthetic, technology.

– by the way, my CV is finally up-to-date! –

assistive devices comparison

what-are-crutch-alternativesTwo weeks ago I stumbled upon this interesting website, which provides useful information about different assistive devices. I tried to make a list of Pros & Cons of crutches, walkers and exoskeletons (as for the latter category, in very general terms) in order to compare them from a more global point of view. The result is the table below here, that you can zoom by a simple click.

Would you help me complete it? For sure it contains mistakes and inaccuracies, and further details should be added 🙂

tableAC