Rapid development of assistive technologies for quadriplegics

Technologie de la readaptation / Revue d’Epidemiolo

1 à 1,5�. Le temps de double appui augmente chez les sains de 15 % pour lamédiane (extrêmes 3 à 18 %) contre seulement 5 % (3 à 11 %). Plusieurspatients et témoins ont eu des difficultés à négocier le tournant devant le muravec rW ou à se lever en utilisant son aide.Discussion.– L’augmentation des temps de parcours et de la durée du pas plusimportante avec les sujets sains témoigne probablement d’un effet moindre surla marche du rôle de stabilisation. La tendance à l’augmentation de la proportionde double appui pourrait signifier une poussée plus importante des sujets sainscontre le rW (vitesse maxi fixe). Ceci est congruent avec l’observation cliniquede variations des angles tronc-verticale et tronc-axe épaules-poignets. L’échecd’un patient, les difficultés aux tournants et au lever avec rW évoquent unproblème d’interface homme-machine. Nous proposons une vitesse adaptée etune interface améliorée.

http://dx.doi.org/10.1016/j.rehab.2012.07.872

English version

CO30-001-e

Non-invasive brain computer interfacesP. Marque

Unite 825 Inserm, service de medecine physique et de readaptation, IRIT,

CHU de Purpan, 1, avenue Poulhes, 31059 Toulouse, FranceE-mail address: [email protected].

Keywords: BCI; Non invasive; Severe disability

Non-invasive brain computer interfaces are systems for recording EEG activityfrom electrodes placed on skull and use this signal to control devices such asaugmentative communication keyboards or electric wheelchairs. For this, theinterfaces use computer devices able to automatically extract some featuresfrom EEG activity. When features occur in response to a stimulus, interfaces aredescribed as synchronous, otherwise we speak of asynchronous interface. Threemajor types of response can be recorded: the P300 ERPs, the steady statepotential, the frequency responses. These interfaces do not require surgery fortheir implantation and as such are defined as non-invasive. Their acquisitionfrequency are very low and their use shall mobilize all the patient’s cognitiveresources. These characteristics mean that for now this type of interface istransiently used only in extreme motor disabilities: ALS, locked in syndrome.But a new tendency is emerging in the recent literature in the field. Theseinterfaces are used to condition the brain activity in a rehabilitative purpose. Theconference will illustrate these issues and will endeavor to show the interest andlimitations of non-invasive brain computer interface.


CO30-002-e

Motor neuroprostheses: Basic principles and applicationsC. Jouffrais

CNRS – UMR5505, institut de recherche en informatique de toulouse (IRIT),

118, route de Narbonne, 31062 Toulouse, FranceE-mail address: [email protected].

Keywords: BCI; Invasive; Microelectrodes; Motor control; Severe disability

Since the late 1960s, behavioural neurophysiology has been focusing onunderstanding the organization of the primate motor system, as well as todecode some of the neural code enabling voluntary movements. After a briefreview of the cortical areas involved in the control of voluntary movement andespecially in the control of hand movement directed towards a visual target, I willdescribe the coding theory of motion by neural populations. I then explain howthese fundamental developments on the coding of the movement were the basis ofa series of recent work on motor neuroprostheses. The results of recent years showthat it is possible for a patient with severe disabilities (quadriplegia after cervicalspinal cord damage, for example) to control by thought various technical aids suchas a robot arm, a computer cursor, a wheelchair or other devices.


CO30-003-e

Electric wheelchair navigation using virtual reality:From intention to actionP. Abellard

Service d’handibio, IUT Toulon, universite du Sud-Toulon-Var, avenue de

l’Universite, BP 20132, 83957 La Garde cedex, FranceAdresse e-mail : [email protected].

Keywords: Electric wheelchair; Simulator; Virtual reality; Assistance;

Rehabilitation

Objective.– The ISIDORE simulator for electric wheelchair mobility has beendeveloped with a triple aim: to help the doctors give out a driving license foroperating an electric wheelchair, to place the patient in a virtual environment inorder to move about safely and to be able to observe both the patient’s behaviorand to quantify important parameters to help the therapist develop actions ofrehabilitation.Material and method.– ISIDORE is a platform, which can be used with anyelectric wheelchair available on the market. It has a microcomputer, which cancollect and process data from the movements of the wheels. To assess theirperformance moving around in a virtual environment (VIRTOOLS) will be usedwith an IMMERSAPOD station. Then the patient will be able to move freely ina familiar environment (hospital, rehabilitation center, foyer for the disabled ora private home) and his or her trajectory will be compared to an optimized one.Then, studying the discrepancies will help set up or upgrade a number ofadditional (visual, sound. . .) devices to provide a better accessibility.Results.– The patient can use three different steering modes: a manual modewith total control; an automatic mode where the wheelchair behaves like amobile robot going from a starting point to a given target and a semi-automaticmode where the user only has to rely on the wheelchair when facing awkwardpositions (blocked passages, going through doors or obstacles to be avoided).Discussion.– The piloting assistance can exploit the inference of intentions: thepreliminary intention (for the mental representation of what the user wants todo; the intention in action for the supervision of the action process at amacroscopic level and the driving intention for the control of the action inprogress. It will then become possible to improve the assistance thanks to adatabase of fuzzy logic rules using the data from different sensors (angles andspeed of lever command movements, head and eyes movements and so on).

Further readingAbellard P, Randria I, Abellard A, Khelifa MB, Ramanantsizehena P. Electricwheelchair navigation simulators: why, when, how? Mechatronic Systems,INTEH; 2010, p. 161–86.


CO30-004-e

Rapid development of assistive technologies for quadriple-gicsP. Truillet *, P. Raynal, C. Jouffrais

Institut de recherche en informatique de Toulouse (IRIT); universite

Paul-Sabatier, 118, route de Narbonne, 31062 Toulouse cedex 9, France

*Corresponding author.E-mail address: [email protected].

Keywords: Disability; Human machine interface; Technical aids

Technical aids enable many quadriplegics to perform tasks they could not dootherwise: read their emails, change TV channel, etc. According to Laffont(2008), the ability to control its environment is crucial to the quality ofrehabilitation, and family. Other works (Pino, 2000; Verdonck, 2009) studiedthe significance of the uses of assistive technologies by persons with tetraplegia.Five major categories were identified as: autonomy, freedom, security, time foroneself and relationships with others.This work suggests that these aids should be seen as a ‘‘fundamental humanright’’ and reaffirm the need to work with users. Nevertheless, there is a largeproportion of technical aids on the market is little or no use. This low acceptancerate is due to several reasons summarized by Philips (1993) and Scherer (1996):lack of attention in the selection of aid, difficulty in obtaining aid, performanceand change needs of the patient.

gie et de Sante Publique 55S (2012) e343–e347 e345


mailto:[email protected]







Technologie de la readaptation / Revue d’Epidemiologie et de Sante Publique 55S (2012) e343–e347e346

The recent development of technologies at a very low cost (either hardwaredevices like arduino, teensy, raspberry ft, or software tools), the public’senthusiasm for the ‘‘DIY’’ (Do It Yourself – Do It Yourself own) (Hurst, 2011)and dissemination of knowledge in human-computer interaction (HCI) showthat it is possible to design ‘‘customized and personalized’’ assistivetechnologies. Moreover, empowering disabled users with development of suchaids may improve the adoption and diffusion of these technologies.In HCI, one of the goals of rapid prototyping is to test a number of innovativesolutions that can be useful to users. The feedback process can then be used forexample to guide further developments. We believe that this process is adequateto design useful systems for deficiencies. We illustrate this process through anexperiment conducted for the design and the implementation of assistivetechnologies for quadriplegics.


CO30-005-e

Nanostructured flexible implantable microelectrodes forstimulation and recording neural activityE. Descamps *, V. Castagnola, S. Charlot, C. Blatche, C. Bergaud

Equipe nanobiosystemes, LAAS-CNRS, universite de Toulouse, 7, avenue du

Colonel-Roche, 31077 Toulouse cedex 4, France


Many people severely disabled following a stroke or a lesion of the spinalcord, remain totally immobilized. In most severe cases, as in the case oflocked-in syndrome (LIS), patients are completely deprived of means ofcommunication and action, while their cognitive abilities are preserved. BCIdevices, based on functional connections between brain and machine, areemployed to direct a cursor on a computer screen in order to use software, totype text. . . The new assistance systems are based evidently on knowledge ofbrain functioning but also on the design of adapted machines (robots,computers, etc.). The physical interface between the brain and the system,composed usually by implantable microelectrodes, is a third fundamentalelement of the device whose properties directly affect the quality of therecording and stimulation.Currently, whatever the kind of employed microelectrodes, two critical aspectsvery disadvantageous for long-term implementations concern the lifetime ofelectrodes, not exceeding a few months after implantation in general, and theirbiocompatibility with a high rejection rate for many implants.Our work combines the surface nanostructuring of electrodes and the use offlexible substrates promoting intimate contact electrode-neurons. Thesecomplementary approaches favor the growth and adhesion of neuronal cells[1]. The modification of the electrode by electrochemical deposition ofconducting polymers (PEDOT) results in an increase of electrode lifetime/stability and improved biocompatibility of devices. Also doping of PEDOT bynano-objects or organic compounds increases the signal to noise ratio byreducing the electrical impedance and promoting the injection of electriccharges which will make the devices much more efficient to stimulate andrecord brain activity. We will present our preliminary results showing that ourapproach reduces the impedance of microelectrodes of more than one order ofmagnitude.

Reference[1] Reichert W. Indwelling neural implants. In: Collection ‘‘Frontiers in

Neuroengineering’’. CRC Press; 2008.


CO30-006-e

Proposed method to assess walking aids in the elderly withobservation and simple timing parametersP. Rumeau a,*, V. Pasqui b, N. Vigouroux c, L. Saint-Bauzel b

a UMR1027, Inserm, laboratoire de gerontechnologie-gerontopole, universite

de Toulouse, CHU de Toulouse, 31000 Toulouse, Franceb ISIR-Paris 6 Jussieu, Paris, France

c Laboratoire de gerontechnologie-gerontopole, IRIT-CNRS, universite de

Toulouse, Toulouse, France


Keywords: Geriatric physical medicine; Preclinical stage; Robuwalker; AAL

DOMEO; ANR/CNSA

Smart walking aids with robotics, adapting to the person and the environment,are most relevant for walking difficulties in the elderly (adding motor, visual,cognitive, hearing impairments. . .). Such devices don’t cope with the Frenchrefunding agreement scheme. A trial-based medicotechnical evaluation isrequired, prior to medical-trials, to check that the device, used by the volunteer,provides the expected service.Method.– Four healthy aged volunteers (H) and 4 patients (P) with walking(v < 1 m/s, Timed Get Up & Go > 13s) and cognitive (MMSE < 26)impairment had 3 tries at 4 M straight-line walk (4 M) then modified TGUG(including going round the chair before seating again) with their usual way (U),then a regular walker (S), then Robuwalker (rW) motorized automat withcommand buttons on the handles, tests were filmed by a single camera.Results.– In both H and P: there is no big difference on 4 M between U and S,with rW time is more increased in the healthy subjects (X5 to 10 vs. 2 to 3). Onepatient failed using the interface even during 4 M. Steps average duration isincreasing 1.8 to 3.4� between S and rW, for H, vs. 1 to 1.5� for P. The durationof double contact is increasing in H with a median of 15% (extremes 3 to 18%)vs. only 5% (3 to 11%) in P. Some P and H failed to turn smoothly in front of thewall with rW or to use it to stand.Discussion.– Increased duration of tasks and steps in H are a clue of a lesserbenefit for them in terms of stability. The trend towards an increased proportionof double contact could mean a push of healthy subjects against rW (fixed maxspeed). This fits with the variations of trunk to vertical and to the shoulder-wristaxis as clinically observed. The failure of two patients, the difficulties at turnsand to stand with rW imply a human robot interface (HRI) problem. We proposethat the speed should adapt to the user and the HRI be improved.


Communications afficheesVersion francaise

P089-f

Prise en charge multidisciplinaire d’un cas complexe depositionnementE. Viollet a,*, F. Nouvel a, F. Pellas b

a Clinique du positionnement et d’aide a la mobilite, CHU de Nımes, place du

Pr-Robert-Debre, 30900 Nımes, Franceb Service de medecine physique et readaptation, service de reeducation post-

reanimation, CHU de Nımes, Nımes, France

*Auteur correspondant.Adresse e-mail : [email protected].

Mots cles : Positionnement au fauteuil ; Multidisciplinaire ; Deficiences

multiples ; Subluxation hanche

Introduction.– La démarche de positionnement est le processus clinique visant àplacer une personne ayant des troubles posturaux, dans une posture requise aumoyen d’une aide technique à la posture. La complexité de certaines situationscliniques associant des déficiences multiples, des limitations d’activité variableset devant être maintenues ainsi que la prise en compte de l’environnement,impose des stratégies multidisciplinaires structurées dont voici un exemple.Observation.– Une patiente de 20 ans présentant un syndrome cérébelleuxbilatéral avec dystonies à type de myotonies prédominant au membre supérieurdroit et hémiparésie gauche suite à l’exérèse d’un astrocytome pylocitique ducervelet est adressée. La principale doléance était l’apparition de douleurs dehanche gauche au fauteuil, limitant la capacité de transfert et de propulsionpodale du fauteuil.En position assise, on observait une rotation droite du bassin de plus de 258, pasd’obliquité de bassin, un membre inférieur gauche plus court en rotation interneet en abduction. En décubitus dorsal : limitation de la flexion de hanche gauche à608 avec une spasticité des adducteurs cotée à 3 (Ashworth). Les radiographies







Documents

Rapid development of assistive technologies for quadriplegics