Browsing by Author "Villa-Bedoya, J. (Juliana)"

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    PublicationOpen Access
    Development of an electro-mechanically controlled hand orthosis for assisting finger extension in stroke survivors
    (2014-04-20) Villa-Bedoya, J. (Juliana); Petroff, N. (Neil)
    Stroke is the leading cause of long-term disability in the world. It causes chronic deficits, such as hemiparesis, especially prevalent in the distal upper extremities. An electro-mechanically driven hand orthosis has been developed to assess the potential therapeutic use of such devices in rehabilitating hand function. A small Direct Current (DC) brushed motor is used as the main actuator, and a cable-driven glove connected to the motor shaft is the central component of the device. The orthosis control is achieved through a force feedback loop using a miniature load cell attached in series to the cable and control module. The later, generates Pulse Width Modulated (PWM) and direction signals required to drive the motor. The speed is determined by the duty cycle of the PWM signal while the direction by the status of a flag bit modified by a user-operated switch. A portable design was achieved by using a 6 V battery pack as the power supply. The device is ready for use in clinical trials with stroke survivor subjects as it has already been tested on healthy individuals with satisfactory performance.
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    PublicationOpen Access
    SpeedMed: device for measuring velocity in track sports
    (2014-04-20) Sánchez-Aldana, N. (Natalia); Velásquez-Gómez, J. (Juliana); Villa-Bedoya, J. (Juliana); Marín-Correa, J. M. (Juan Manuel)
    Everyday, industries make use of economic resources to carry on research studies of products to improve the athletic performance of people. This is the main reason why it is believed that the development of an inexpensive and portable device capable of measuring times and speeds in track sports in general will provide useful information to study the performance of not only sportsmen, but also of ordinary people under stress situations allowing them to determine their weaknesses. In this project, two very simple sensors (photocells) are used to develop a device capable of measuring speed. A microcontroller was programmed to measure the time between the interruptions of two laser beams which lighten the surfaces of photocells, and it was also programmed to calculate velocity for a given distance. These values are sent to a Liquid Crystal Display (LCD) where they can be visualized and interpreted.