Implement mechatronics in a cephalic orthosis for children with cerebral palsy

Orientador: João Maurício RosárioDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecânicaResumo: Este estudo objetivou a elaboração de uma proposta mecatrônica em uma órtese cefálica, para crianças com paralisia cerebral, tetraparéticas, não deambulantes, entre 2 anos e 12 anos de idade. Para a fundamentação do mesmo realizou-se a revisão bibliográfica sobre o uso de órteses cefálicas e / ou outros recursos assistivos para facilitar o controle da cabeça nessas crianças, tendo em vista a importância sócio-educacional desse controle para o desenvolvimento integral e qualidade de vida de uma pessoa. Complementa-se essa fundamentação com a apresentação do estudo realizado em pesquisa experimental com essa órtese, em grupo controle de crianças, contextualizando seus resultados e examinando-se as hipóteses neuroplásticas para a compreensão dos ganhos demonstrados pela utilização da órtese. São também apresentadas as dificuldades encontradas no modelo mecânico, que resultaram na busca para a implementação mecatrônica. Através desta possibilidade vislumbra-se controlar a aplicabilidade da órtese e coletar dados das regulagens efetivadas na cabeça do usuário. Ampliando sua aplicação sugere-se a utilização desta órtese com uma cadeira motorizada, com comando mecatrônico integrado. Este estudo conclui a necessidade de realizar-se uma nova pesquisa para referendar se os resultados obtidos, até o presente momento com a órtese cefálica, confirmam e validam sua eficácia como agente terapêutico que promove controle motor voluntário de cabeça em crianças com paralisia cerebralAbstract: The purpose of this study was to elaborate a mechatronic proposal using a Cephalic Orthosis for children with Cerebral Palsy, quadriplegics, and non-ambulatories between the ages of two and 12. For the basis of said study, a revised bibliography about the use of the Cephalic Orthosis and/or other assistive resources was utilized to facilitate control over the heads of these children, taking into consideration the importance of the socio-educational aspects of this control to the development and quality of life of the individual as a whole. Experimental research with the Orthosis in a control group of children contextualizes and supports it's results through examining the neuro-plastics hypothesis for better comprehension of gains demonstrated by utilizing the Orthosis. Difficulties encountered when using this mechanical model are also presented, as well as the need to implement mechatronics. Through the possible use of the orthosis, the main goal is to ensure beneficial results and collect data of said results while regulating the changes made. In conclusion, this study shows the need for further research, in order to confirm if the up-to-date results obtained utilizing the Cephalic Orthosis confirms and validates its efficacy as a therapeutic agent, which promotes voluntary motor control of the head in children with Cerebral PalsyMestradoMecanica dos Sólidos e Projeto MecanicoMestra em Engenharia Mecânic

Development and Evaluation of Facial Gesture Recognition and Head Tracking for Assistive Technologies

Globally, the World Health Organisation estimates that there are about 1 billion people suffering from disabilities and the UK has about 10 million people suffering from neurological disabilities in particular. In extreme cases these individuals with disabilities such as Motor Neuron Disease(MND), Cerebral Palsy(CP) and Multiple Sclerosis(MS) may only be able to perform limited head movement, move their eyes or make facial gestures. The aim of this research is to investigate low-cost and reliable assistive devices using automatic gesture recognition systems that will enable the most severely disabled user to access electronic assistive technologies and communication devices thus enabling them to communicate with friends and relative. The research presented in this thesis is concerned with the detection of head movements, eye movements, and facial gestures, through the analysis of video and depth images. The proposed system, using web cameras or a RGB-D sensor coupled with computer vision and pattern recognition techniques, will have to be able to detect the movement of the user and calibrate it to facilitate communication. The system will also provide the user with the functionality of choosing the sensor to be used i.e. the web camera or the RGB-D sensor, and the interaction or switching mechanism i.e. eye blink or eyebrows movement to use. This ability to system to enable the user to select according to the user's needs would make it easier on the users as they would not have to learn how to operating the same system as their condition changes. This research aims to explore in particular the use of depth data for head movement based assistive devices and the usability of different gesture modalities as switching mechanisms. The proposed framework consists of a facial feature detection module, a head tracking module and a gesture recognition module. Techniques such as Haar-Cascade and skin detection were used to detect facial features such as the face, eyes and nose. The depth data from the RGB-D sensor was used to segment the area nearest to the sensor. Both the head tracking module and the gesture recognition module rely on the facial feature module as it provided data such as the location of the facial features. The head tracking module uses the facial feature data to calculate the centroid of the face, the distance to the sensor, the location of the eyes and the nose to detect head motion and translate it into pointer movement. The gesture detection module uses features such as the location of the eyes, the location of the pupil, the size of the pupil and calculates the interocular distance for the detection of blink or eyebrows movement to perform a click action. The research resulted in the creation of four assistive devices based on the combination of the sensors (Web Camera and RGB-D sensor) and facial gestures (Blink and Eyebrows movement): Webcam-Blink, Webcam-Eyebrows, Kinect-Blink and Kinect-Eyebrows. Another outcome of this research has been the creation of an evaluation framework based on Fitts' Law with a modified multi-directional task including a central location and a dataset consisting of both colour images and depth data of people performing head movement towards different direction and performing gestures such as eye blink, eyebrows movement and mouth movements. The devices have been tested with healthy participants. From the observed data, it was found that both Kinect-based devices have lower Movement Time and higher Index of Performance and Effective Throughput than the web camera-based devices thus showing that the introduction of the depth data has had a positive impact on the head tracking algorithm. The usability assessment survey, suggests that there is a significant difference in eye fatigue experienced by the participants; blink gesture was less tiring to the eye than eyebrows movement gesture. Also, the analysis of the gestures showed that the Index of Difficulty has a large effect on the error rates of the gesture detection and also that the smaller the Index of Difficulty the higher the error rate

Evaluation of vision-based head-trackers for assistive devices

This paper presents a new evaluation methodology for assistive devices employing head-tracking systems based on an adaptation of the Fitts Test. This methodology is used to compare the effectiveness and performance of a new vision-based head tracking system using face, skin and motion detection techniques with two existing head tracking devices and a standard mouse. The application context and the abilities of the user are combined with the results from the modified Fitts Test to help determine the most appropriate devices for the user. The results suggest that this modified form of the Fitts test can be effectively employed for the comparison of different access technologies