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This paper proposes a framework for constructing and training a radial basis function (RBF) neural network. For this purpose, a sequential learning algorithm is presented to adapt the structure of the network, in which it is possible to create a new hidden unit and also to detect and remove inactive units. The structure of the Gaussian functions is modi"ed(More)
Clinical applications such as artificial vision require extraordinary, diverse, lengthy and intimate collaborations among basic scientists, engineers and clinicians. In this review, we present the state of research on a visual neuroprosthesis designed to interface with the occipital visual cortex as a means through which a limited, but useful, visual sense(More)
—We describe a pipelined optical-flow processing system that works as a virtual motion sensor. It is based on a field-programmable gate array (FPGA) device enabling the easy change of configuring parameters to adapt the sensor to different speeds, light conditions and other environmental factors. We refer to it as a " virtual sensor " because it consists of(More)
Motivated by the success of cochlear implants for deaf patients, we are now facing the goal of creating a visual neuroprosthesis designed to interface with the occipital cortex as a means through which a limited but useful sense of vision could be restored in profoundly blind patients. We review the most important challenges regarding this neuroprosthetic(More)
OBJECTIVE Brain-computer interfaces based on steady-state visual evoked potentials (SSVEP-BCIs) achieve the highest performance, due to their multiclass nature, in paradigms in which different visual stimuli are shown. Studies of independent binary SSVEP-BCIs have been previously presented in which it was not necessary to gaze at the stimuli at the cost of(More)
This paper describes a bioinspired preprocessing and coding system devised for producing optimal multi-electrode stimulation at the cortical level, starting from image sequences and working at video rates. A hybrid platform with software and reconÿgurable hardware delivers a continuously varying stream of pulses or spike patterns. The main objective of this(More)
The cooperation between neuroscience and biomedical engineering gave rise to a recent, but growing research field, known as neuroengineering. We follow its principles to have a system providing basic descriptions of the visual world to the brain's cortex. We describe a set of software and hardware tools to interface with neural tissue, in order to transmit(More)
As there are many possibilities to select the set of basic operators used in the fuzzy inference process, the search for the fuzzy operators that are most suitable for the different steps of a fuzzy system, their characterization and evaluation, can be included among the most important topics in the field of fuzzy logic. A better insight into the(More)
Brain–computer interfaces (BCIs) are mainly intended for people unable to perform any muscular movement, such as patients in a complete locked-in state. The majority of BCIs interact visually with the user, either in the form of stimulation or biofeedback. However, visual BCIs challenge their ultimate use because they require the subjects to gaze, explore(More)