The Capture of Eye Electrical Potential for Viable Use in Human-Machine Interfaces
Figura 1: a. Posición de los electrodos (A= 1 pulgada de pupila hacia arriba, B= en la sien derecha del paciente, C= 1 pulgada de pupila hacia abajo, D= 1 pulgada de pupila hacia arriba, E= en la sien izquierda del paciente; b. Ejes donde se registraron los movimientos de los ojos (cada círculo concéntrico tiene una diferencia en el radio de 10cm; U, R, D, L significa arriba, derecha, abajo, y arriba respectivamente).
The capture of ocular signals is useful for controlling human-machine interfaces in patients suffering from disabling motor diseases (e.g., amyotrophic lateral sclerosis, or unfortunate events, such as accidents, that leave the patient with a severe disability). Such interfaces aim to improve their quality of life. Thus, this research aims to develop a low-cost device for capturing eye signals that allow it to be used in HMIs. Materials and methods: A device was designed and validated in a population of 10 adult students from the Faculty of Biomedical Engineering of the Specialized University of the Americas (Panama), and the potential of vertical and horizontal eye movement were recorded. Results: The magnitude of the signal is directly proportional to the ocular displacement. Furthermore, there is no significant statistical difference among the recorded potential for a specific ocular displacement; that is, both the left and the right eye marked the same potential for same displaced distances. The minimum potential recorded was 88.0 ± 16.8 mV, and the maximum was 382.0 ± 72.08mV. The device was connected to a variable intensity light bulb, and depending on the registered potential, the intensity of the light changed. Thus, the device could be used as an interface in an HMI. Conclusion: The statistical analysis showed the reliability of the designed device (myoelectric signal collector). When the
LED is switched on, the possibility of the equipment being used for human machine interfaces is shown.