This paper reports on a fully miniaturized brain-machine-spinal cord interface (BMSI) for closed-loop cortical control of intraspinal microstimulation (ISMS). The system incorporates two identical 4-channel modules, w...
详细信息
ISBN:
(纸本)9781509029600
This paper reports on a fully miniaturized brain-machine-spinal cord interface (BMSI) for closed-loop cortical control of intraspinal microstimulation (ISMS). The system incorporates two identical 4-channel modules, with each module comprising a neural recording front-end, embedded digital signal processing (DSP) unit, and programmable stimulating back-end. The DSP unit is capable of generating multichannel trigger signals for a wide array of ISMS triggering patterns based upon online discrimination of a programmable number of intracortical neural spikes within a pre-specified time bin via thresholding and time-amplitude windowing. The BMSI system is validated experimentally in a rat model of contusion spinal cord injury (SCI) by converting in real-time multichannel neural spikes recorded from the cerebral cortex into electrical stimuli delivered to the lumbar spinal cord below the level of the injury, resulting in distinct patterns of hindlimb muscle activation in the SCI rat.
In this paper we present a new computational primitive for convolution using coupled oscillator arrays. It is based on a Degree of Match (DOM) operation for pairs of vectors of analog voltage encoded data. The convolu...
详细信息
In this paper we present a new computational primitive for convolution using coupled oscillator arrays. It is based on a Degree of Match (DOM) operation for pairs of vectors of analog voltage encoded data. The convolution operation is synthesized from these DOM circuits and computes the precise mathematical convolution of the two vectors. We present an example circuit design for the DOM operator and SPICE simulations of the circuit behavior. A MATLAB model is curve fit to an inverted copy of this output and shown to be roughly equivalent to the square of the Euclidian distance between the vectors. Using a parameterized version of this model we conducted a MATLAB study to analyze the accuracy of the DOM and convolution operations under variations in oscillator array symmetry, locking range, and additive noise. We also show a small example of convolution with an edge enhancement filter.
The assembly line balancing problem (ALBP) consists in finding the best assignment of tasks between several workstations. An evenly distribution reduces idle time and therefore results in more efficient production sys...
详细信息
The assembly line balancing problem (ALBP) consists in finding the best assignment of tasks between several workstations. An evenly distribution reduces idle time and therefore results in more efficient production systems. Although several models have been proposed for ALBP, real lines present restrictions that usually violate simplifications assumptions. This paper presents a hybrid genetic algorithm to solve balancing problems with assignment restrictions. Heuristics are dynamically used in the encoding process to reduce search space and to focus the search on promising areas. The hybrid GA is able to obtain solutions close to the optimal (0.79% in average) for the most used dataset in the literature. The presented GA can incorporate equipment or zoning restrictions that might be present in real assembly lines.
Ferromagnetic materials have magnetic properties which determine its magnetic field conductivity characteristics. Such characteristics are extremely important for the proper selection and use of these materials in mea...
详细信息
Ferromagnetic materials have magnetic properties which determine its magnetic field conductivity characteristics. Such characteristics are extremely important for the proper selection and use of these materials in measurement processes, for example. Therefore, this paper presents an equipment for the characterization of ferromagnetic materials constructed in a laboratory. The experimental results of this equipment are acquired and compared with the experimental results obtained with an industrially manufactured apparatus called hysteresisgraph, designed to provide magnetic characterization of magnetic materials. The results of the comparison demonstrate that the equipment presented has low relative error and can be applied in academic projects which require magnetic characterization of ferromagnetic materials developed in the laboratory.
Thermoelectric (TE) modules are solid-state devices that convert directly thermal energy in electrical energy. However, they can undergo performance degradation due to thermal cycling. In the present study, a control-...
详细信息
The integration of lower limb exoskeletons with robotic walkers allows obtaining a system to improve mobility and security during gait rehabilitation. In this work, the evaluation of human motion intention (HMI) based...
详细信息
A compact electromagnetic multi-resonator is presented in this paper using a new technique for chipless RFID tag data encoding. Employing Archimedean spirals, the information is applied into the spectral signature shi...
详细信息
Choosing the ideal spot to set up an Access Point (AP) in a given plant is no simple task. This paper proposes a mathematical model and computational solution to the following problem: given the plant of an indoor env...
详细信息
Choosing the ideal spot to set up an Access Point (AP) in a given plant is no simple task. This paper proposes a mathematical model and computational solution to the following problem: given the plant of an indoor environment, a number of reception points and properly characterized obstacles, locate where the access point should be installed, so as to minimize the propagation losses within the environment and ensure a minimum signal level in all receivers. The model proposed differs from others in the literature by treating each obstacle individually and taking into account the material from which it is made. The proposed design minimizes the sum of the attenuations of the signal generated by the AP as the signal traverses the fewest possible obstacles whose attenuation is large (e.g., concrete walls and metal cabinets). To validate the proposed model simulations were performed in an indoor environment with a certain distribution of obstacles of different kinds. The experiments show that the location of the access point varies significantly in the environment according to the materials composing the obstacles. In the most critical case, with obstacles made of concrete, the optimization algorithm could find no location for the AP so that all receptors received a minimum signal level to establish a connection.
We present a non-imaging light-field microscopy method for volume quantification of neural activity in scattering brain tissue. Individual neuron fluorescence is computed directly by independent component identificati...
详细信息
A prominent change is being carried out in the fields of rehabilitation and assistive exoskeletons in order to actively aid or restore legged locomotion for individuals suffering from muscular impairments, muscle weak...
详细信息
ISBN:
(纸本)9781424492695
A prominent change is being carried out in the fields of rehabilitation and assistive exoskeletons in order to actively aid or restore legged locomotion for individuals suffering from muscular impairments, muscle weakness, neurologic injury, or disabilities that affect the lower limbs. This paper presents a characterization of knee motion patterns from Surface Electromyography (sEMG) signals, measured in the Erector spinae (ES) muscle. Feature extraction (mean absolute value, waveform length and auto-regressive model) and pattern classification methods (Linear Discrimination Analysis, K-Nearest Neighborhood and Support Vector Machine) are applied for recognition of eight-movement classes. Additionally, several channels setup are analyzed to obtain a suitable electrodes array. The results were evaluated based on signals measured from lower limb using quantitative metric such as error rate, sensitivity, specificity and predictive positive value. A high accuracy (> 95%) was obtained, which suggest that it is possible to detect the knee motion intention from ES muscle, as well as to reduce the electrode number (from 2 to 3 channels) to obtain an optimal electrodes array. This implementation can be applied for myoelectric control of lower limb active exoskeletons.
暂无评论