Thesis (Ph.D)--Bioengineering, Georgia Institute of Technology, 2010. / Committee Chair: Sprigle, Stephen; Committee Member: Brani Vidakovic; Committee Member: Charlie Lachenbruch; Committee Member: John L. Lin; Committee Member: Rudy Gleason. Part of the SMARTech Electronic Thesis and Dissertation Collection.

A quick-connect wheelchair power add-on unit (PAU) has been developed at the Human Factors Engineering Center of Virginia Tech. The objective of the new invention is to provide an inexpensive, highly portable product which can quickly convert a manual wheelchair into a power-operated wheelchair. This dissertation details the three year research and design effort to develop the new wheelchair PAU. Results are presented from a series of evaluations conducted to identify performance and user-interaction characteristics of the PAU. Interpretation of the results provides a prioritized list of identified design deficiencies along with wheelchair expert and design team suggestions for the next generation of design alterations. The three evaluations conducted with the second generation PAU prototype include a series of wheelchair expert interviews, a PAU performance evaluation, and a usability evaluation which utilized wheelchair operators as subjects. Also included in the dissertation is an explanation of the need for a new PAU, a description of the most recent design iteration, a literature review containing information about the history of wheelchairs, the condition of the current PAU market, and an analysis of wheelchair PAU consumers. The new invention was conceived and patented by Dr. John G. Casali of the Industrial and Systems Engineering (ISE) Department at Virginia Tech. This research was supported jointly by Southwestern Applied Technologies, L. C., of Roanoke, Virginia and Virginia's Center for Innovative Technology in Herndon, Virginia. / Ph. D.

In the wheelchair family, a manual wheelchair is most commonly used by the lower-limb disabled, while its manual mode creates the lowest mechanical effi-ciency and the highest rate of upper-limb injury. Electric wheelchairs on the market are much more labor-saved; however, with their drive systems mostly combining with the bodies of the wheelchair, electric wheelchairs appear to be bulky and are not easily-carried. While in a limited space, on a short-distance moving, or in/off the elevator, electric wheelchairs cannot be practicably switched to manual ones. Thus, this text aims to develop a switchable dou-ble-action manual/electric wheelchair with an auxiliary driving wheel, expect-ing to increase the mechanical efficiency and not to enlarge the body of the wheelchair; the module-disassembled drive system is intended for the conven-ience of carrying. Besides, in order to keep both the manual and the electric functions, the caster contains a set of separable orientation control system, while enables the caster to be switched in both the modes of 360-degree rotation and of being controlled by the user. In this way, the use of the wheelchair would be-come much more multiple-choice.

The overall goal of this research is to improve the use of seated tilt to increase function, health and quality of life for people using power wheelchairs. Specifically, the objective of this dissertation is to evaluate the biomechanical responses to seated full body tilt and their relationships to the actual use of tilt-in-space wheelchairs. In the first phase of this study, researchers remotely monitored how 45 fulltime power wheelchair users used their tilt-in-space systems. Participants spent an average of 12.1 hours in their wheelchair each day. They spent more than 2 hours seated at positions greater than 15° and performed tilts of 5° or greater every 27 minutes, but rarely performed tilts past 30°. Two distinct types of tilt behavior were identified: uni-modal (staying at a single position more than 80% of the time) and multi-modal (staying at a single position less than 80% of the time). Participants in the multi-modal group tilted significantly more frequently (4 times per hour) than the uni-modal group, and did not have a single typical position. Participants without sensation were more likely to exhibit uni-modal behavior. In the second phase of this study, researchers used interface pressure measurements and laser Doppler flowmetry to study changes in localized loading and superficial blood flow at the ischial tuberosities across different amounts of tilt. Eleven participants with spinal cord injuries were studied in a laboratory setting. Results showed that biomechanical responses to tilt were highly variable. Pressure reduction at the ischial tuberosity was not present at 15°, but did occur with tilts to 30° and greater, and could be explained by the tilt position and upright pressure. Unlike pressure, blood flow increased with all tilts from an upright position, but did not increase when tilting from 15° to 30°. Only 4 of 11 participants had a considerable increase (≥10%) in blood flow at 30° tilt, whereas 9 participants did during maximum tilt (i.e., 45°-60°). Based on the results of this study, tilting for pressure reliefs as far as the seating system permits is recommended to maximize the potential for significant blood flow increases and pressure relief.

Diploma thesis deals with design of electric wheelchair. Final product is standing on the bases from the designer and technical analysis. The main goal is to create electric wheelchair with a charakteristic appearance, that will respect user health condition and ergonomic and technical parameters as well.

Permobil AB är ett medicintekniskt företag som bland annat tillverkar elektriska rullstolar. Till dessa rullstolar existerar i nuläget inte en större förvaringslösning som tillåter brukare enkel tillgång till innehållet. Frånvaron av förvaring leder till att improviserade och hemmagjorda lösningar används, vilket i sin tur leder till sekundära problem som exempelvis försämrad stabilitet och trycksår. Projektets mål var därför att skapa en prototyp (inklusive dess 3D-modeller) som tillät upp till 20 liter förvaring med tillgänglighet för brukaren. Projektets övergripande syfte var att öka självständigheten hos Permobils brukare och att öka deras möjlighet till deltagande i vardagsaktiviteter. Givet rådande Covid-19 omständigheter vid tidpunkten för detta arbete så utfördes inga användbarhetstester direkt mot brukare för att minimera smittspridning av viruset. Prototypen avgränsades även till att endast anpassas till Permobils sitssystem Corpus. Designprocessen användes som projektets huvudsakliga utvecklingsmetod där datainsamling bestod av inledande användbarhetstester i syftet att se problem och behov, användarhistorier, en användarresa och en riskanalys. Samtliga delar bidrog till skapandet av en kravspecifikation. I projektets designinriktade delar skapades tre moodboards och två tillfällen hölls med Permobils anställda för att skissa på idéer och lösningsförslag. Koncept som valdes att vidareutvecklades utvärderades genom 3D-modellering samt via skapandet av fysiska prototyper. De fysiska prototyperna funktionstestades mot den elektriska rullstolen för att utvärdera rörelsemönster, begränsningar och infästningsmöjligheter. En slutgiltig prototyp erhölls, där ett mekaniskt system omvandlade en linjär rörelse till en cirkulär. Rörelsen motsvarade 90° och tillät exempelvis väskor och påsar i storleken 20 liter att förflytta sig från den elektriska rullstolens rygg till dess sida. Projektets mål ansågs därför uppfyllda. Inga utmattningstester utfördes på prototypen då det varken var ekonomiskt eller tidsmässigt lönsamt i dess tidiga stadie och ska-krav som existerar på grund av ISO-standarder uppfylldes därför inte. Simuleringar och ytterligare utveckling i aluminium hade också varit nödvändigt för att bekräfta och uppfylla att konstruktionen håller för den önskade maxvikten. Resterande krav ansågs uppfyllda. Då ytterligare tester och förbättringar behövs så kan inte syftet för projektet anses vara uppfyllt, men visionen om en ökad självständighet lever vidare med prototypens vidareutveckling. / Permobil AB is a medical technology company that, among other things, manufactures electric wheelchairs. There is currently no major storage solution for these wheelchairs that allows users easy access to the content. The absence of storage leads to the use of improvised and home-made solutions, which in turn leads to secondary problems such as impaired stability and pressure ulcers. The project's goal was therefore to create a prototype (including its 3D models) that allowed up to 20 liters of storage with accessibility for the user. The overall purpose of the project was to increase the independence of Permobil's users and to increase their ability to participate in everyday activities. Given the prevailing Covid-19 circumstances at the time of this work, no usability tests were performed directly on users to minimize the spread of the virus. The prototype was chosen to be adapted only to Permobil's seating system Corpus. The design process was used as the project's main development method where data collection consisted of initial usability tests in order to see problems and needs, user stories, a user journey and a risk analysis. All parts contributed to the creation of a requirements specification. In the design-oriented parts of the project, three mood boards were created and two occasions were held with Permobil's employees to sketch ideas and solution proposals. Concepts chosen to be further developed were evaluated through 3D modeling and the creation of physical prototypes. The physical prototypes were functionally tested against the electric wheelchair to assess movement patterns, limitations and attachment possibilities. A final prototype was obtained, in which a mechanical system converted a linear motion into a circular one. The movement corresponded to 90° and allowed, for example, bags in the size of 20 liters to move from the back of the electric wheelchair to its side. The project's goals were therefore considered achieved. No fatigue tests were performed on the prototype as it was neither economically nor temporally profitable in its early stages and requirements that exist due to ISO standards were therefore not met. Simulations and further development in aluminum are also necessary to confirm and fulfill that the construction holds for the desired maximum weight. The remaining requirements were considered met. As further tests and improvements are needed, the purpose of the project cannot be considered fulfilled. Still, the vision of increased independence lives on with the further development of the prototype.

No description available.

Tato diplomová práce představuje koncept elektrického invalidního vozíku ovládaného lidskou myslí. Tento koncept je určen pro osoby, které elektrický invalidní vozík nemohou ovládat klasickými způsoby, jakým je například joystick. V práci jsou popsány čtyři hlavní komponenty konceptu: elektroencefalograf, brain-computer interface (rozhraní mozek-počítač), systém sdílené kontroly a samotný elektrický invalidní vozík. V textu je představena použitá metodologie a výsledky provedených experimentů. V závěru jsou nastíněna doporučení pro budoucí vývoj.

L’objectif du travail de cette thèse est la contribution au développement de nouvelles techniques dans le domaine dessystèmes de détection sans marqueur pour une utilisation dans trois domaines vitaux de la santé en utilisant des capteursinnovants et peu coûteux. Pour la réalisation de nos objectifs nous avons eu recours principalement à de l’électroniqueembarquées et du traitement du signal en utilisant le capteur Kinect. Des résultats encourageants ont été obtenus et sontprésentés tout au long de cette thèse. Dans la première partie de ce travail, nous présentons un nouveau système desurveillance visuelle sans marqueur en temps réel pour détecter et suivre les personnes âgées et surveiller leurs activitésdans leur environnement intérieur en utilisant un réseau de capteurs Kinect. Le système identifie également l’événementde chute des personnes âgées sous surveillance. Dans la deuxième partie nous utilisons également le capteur Kinectmais cette fois ci pour la détection sans marqueur des mouvements de la tête d’un patient lors d’un examen utilisant LaTomographie par Emission de Positons (CT/PET) du cerveau. Ce travail est basé sur la compensation de la dégradationde l’image TEP due aux mouvements de la tête du patient. Pour nos essais un cobaye dit « fantôme » a été réalisé,les résultats sur le fantôme sont prometteur ce qui a donné lieu à un test sur un vrai patient volontaire. Les résultatsfinaux montrent l’efficacité de ce nouveau système. La troisième partie du travail présente la mise en oeuvre d’un nouveausystème intelligent pour contrôler un fauteuil roulant électrique par des mouvements spéciaux de la tête toujours sansmarqueur. Un algorithme adapté est conçu pour détecter en continu les degrés des mouvements du visage en utilisant lecapteur Kinect. Fautes de fauteuil roulant électrique, le système a été testé sur un véhicule radio commandé. / The objective of the work of this thesis is the contribution in developing novel technical methods in the field of marker-lesssensing systems for use in three vital health areas by using new inexpensive sensors. Several scientific areas are involvedin achieving our objective such as; electronics and signal processing by using the Kinect sensor. Encouraging results wereachieved as presented throughout this thesis. In the first part of this work we present a new real-time marker-less visualsurveillance system for detecting and tracking seniors and monitoring their activities in the indoor environment by usingnetwork of Kinect sensors. The system also identifies the fall event with the elderly. In the second part, we present anew approach for a marker-less movement detection system for influential head movements in the brain Positron EmissionTomography imaging (CT/PET) by employing the Kinect sensor. This work addresses the compensation of the PET imagedegradation due to subject’s head movements. A developed particular phantom and volunteer studies were carried out.The experimental results show the effectiveness of this new system. The third part of the work presents the design andimplementation of a new smart system for controlling an electric wheelchair by special mark-less head movements. Anadaptable algorithm is designed to continuously detect the rotation degrees of the face pose using the Kinect sensor inreal-time that are interpreted as controlling signals through a hardware interface for the electric wheelchair actuators.