Marilda Machado Spindola

Prototype of a Wheelchair Controlled by Cervical Movements

This work presents the development of a motorized wheelchair controlled by cervical movements, where two accelerometers are used as sensors in the definition of movement commands of the wheelchair. One accelerometer is positioned in a helmet on the users head and the second is positioned on chair base. The use of two sensors has the objective of collecting the signals in differential form providing to system the capability to recognise horizontal plane and slant. The microcontroller STM32F100RB is responsible for processing the signals provided by sensors and for generating the control signals of the wheelchair. Throughout the text are shown the response of accelerometers as a function of the angles of the frontal and transverse tilt of the head, the curves of electric current, the RPM and the efficiency of the transmission system on each wheel as a function of torque, the speed of the wheels as a function of encoder signal frequency and the parameters of the control system adopted. Tests of the wheelchair performance in horizontal and inclined planes were executed and discussed.

A study to implement a Brain-Computer Interface (BCI) based on Sensorimotor Rhythms

This academic article describes an offline research aiming to implement a Brain-Computer Interface (BCI) system based on the manipulation of Sensorimotor Rhythms (SMR) acquired from the Electroencephalograph (EEG). The specific frequencies for each volunteer were found with the analysis of the Distinction-Sensitive Learning Vector Quantization (DSLVQ) algorithm. Extracting features was performed using the Power Samples method whereas the pattern recognition with the Linear Discriminant Analysis (LDA) classification. The results reached 100% correct for a databank (DataSet I) already validated and 80% correct for the voluntary of this research (PAT14).

Prototype of a wheelchair controlled by cervical movements using inertial sensors operating in differential mode

This work presents the development of a motorized wheelchair controlled by cervical movements, where two accelerometers are used as sensors in the definition of movement commands of the wheelchair. One accelerometer is positioned in a helmet on the user’s head and the second is positioned on chair base. The use of two sensors has the objective of collecting the signals in differential form providing to system the capability to recognize horizontal plane and slant. The microcontroller STM32F100RB is responsible for processing the signals provided by sensors and for generating the control signals of the wheelchair. Throughout the text are shown the response of accelerometers as a function of the angles of the frontal and transverse tilt of the head, the curves of electric current, the RPM and the efficiency of the transmission system on each wheel as a function of torque, the speed of the wheels as a function of encoder signal frequency and the parameters of the control system adopted. Tests of the wheelchair performance in horizontal and inclined planes were executed and discussed.

Cognitive Measure on Different Profiles

Based on neurology and cognitive science many studies are developed to understand the human model mental, getting to know how human cognition works, especially about learning processes that involve complex contents and spatial-logical reasoning. Event Related Potential - ERP - is a basic and non-invasive method of electrophysiological investigation. It can be used to assess aspects of human cognitive processing by changing the rhythm of the frequency bands brain indicate that some type of processing or neuronal behavior. This paper focuses on ERP technique to help understand cognitive pathway in subjects from different areas of knowledge when they are exposed to an external visual stimulus. In the experiment we used 2D and 3D visual stimulus in the same picture. The signals were captured using 10 (ten) Electroencephalogram - EEG - channel system developed for this project and interfaced in a ADC (Analogical Digital System) board with LabVIEW system - National Instruments. That research was performed using project of experiments technique - DOE. The signal processing were done (math and statistical techniques) showing the relationship between cognitive pathway by groups and intergroups.