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2.
Clin Neurophysiol ; 121(5): 777-83, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20110193

RESUMO

OBJECTIVES: The principle underlying this project is that, despite nervous reorganization following upper limb amputation, original pathways and CNS relays partially maintain their function and can be exploited for interfacing prostheses. Aim of this study is to evaluate a novel peripheral intraneural multielectrode for multi-movement prosthesis control and for sensory feed-back, while assessing cortical reorganization following the re-acquired stream of data. METHODS: Four intrafascicular longitudinal flexible multielectrodes (tf-LIFE4) were implanted in the median and ulnar nerves of an amputee; they reliably recorded output signals for 4 weeks. Artificial intelligence classifiers were used off-line to analyse LIFE signals recorded during three distinct hand movements under voluntary order. RESULTS: Real-time control of motor output was achieved for the three actions. When applied off-line artificial intelligence reached >85% real-time correct classification of trials. Moreover, different types of current stimulation were determined to allow reproducible and localized hand/fingers sensations. Cortical organization was observed via TMS in parallel with partial resolution of symptoms due to the phantom-limb syndrome (PLS). CONCLUSIONS: tf-LIFE4s recorded output signals in human nerves for 4 weeks, though the efficacy of sensory stimulation decayed after 10 days. Recording from a number of fibres permitted a high percentage of distinct actions to be classified correctly. Reversal of plastic changes and alleviation of PLS represent corollary findings of potential therapeutic benefit. SIGNIFICANCE: This study represents a breakthrough in robotic hand use in amputees.


Assuntos
Amputados , Membros Artificiais , Eletrodos Implantados , Mãos , Controle Interno-Externo , Nervo Mediano/cirurgia , Robótica , Nervo Ulnar/cirurgia , Adulto , Amputação Traumática/complicações , Sistemas Computacionais , Estimulação Elétrica , Humanos , Masculino , Nervo Mediano/fisiopatologia , Movimento , Fibras Nervosas , Plasticidade Neuronal , Membro Fantasma/etiologia , Membro Fantasma/fisiopatologia , Membro Fantasma/cirurgia , Sensação , Estimulação Magnética Transcraniana , Nervo Ulnar/fisiopatologia
3.
Int Rev Neurobiol ; 86: 39-47, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19607989

RESUMO

Insects exhibit remarkable navigation capabilities that current control architectures are still far from successfully mimic and reproduce. In this chapter, we present the results of a study on conceptualizing insect/machine hybrid controllers for improving autonomy of exploratory vehicles. First, the different principally possible levels of interfacing between insect and machine are examined followed by a review of current approaches towards hybridity and enabling technologies. Based on the insights of this activity, we propose a double hybrid control architecture which hinges around the concept of "insect-in-a-cockpit." It integrates both biological/artificial (insect/robot) modules and deliberative/reactive behavior. The basic assumption is that "low-level" tasks are managed by the robot, while the "insect intelligence" is exploited whenever high-level problem solving and decision making is required. Both neural and natural interfacing have been considered to achieve robustness and redundancy of exchanged information.


Assuntos
Encéfalo/fisiologia , Insetos/anatomia & histologia , Voo Espacial/instrumentação , Interface Usuário-Computador , Animais
4.
Biosens Bioelectron ; 20(10): 1968-76, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15741065

RESUMO

The accurate determination of biological parameters by means of rapid, on-line measurements at low-concentrations is an important task within the fields of pharmaceutical screening and medical diagnostic. Nevertheless, in biological samples, the analytes of interest are present as minor components in complex mixtures and with interfering species. Biosensors are the best candidates for these applications providing a direct solution to this need of accuracy, but their intrinsic selectivity often excludes all the other components in the sample. A separation step introduced prior to the sensing component could allow both the increase of selectivity with respect the interfering species and the identification of a large spectrum of molecular components in the sample. This work reports the development of a silicon-based integrated separation microsystem for gas chromatography aimed to biomedical applications, with particular emphasis to monitor the homovanillic acid (HVA) and vanillylmandelic acid (VMA) ratios in mass population screening for neuroblastoma diagnosis and prognosis. The miniaturised system consists of two main modules: (i) a metal oxide semiconductor detector and (ii) a micromachined separation capillary column. As first step, the metal oxide semiconductor capability to detect HVA and VMA has been demonstrated. Then, a technology for a silicon separation capillary microcolumn including the on-chip gas sensor housing has been proposed and a first prototype has been developed. The proposed microsystem is an analytical device with biosensing capabilities for diagnostic and biomedical applications, which yield an electronic signal proportional to the concentration of a specific analyte or group of analytes.


Assuntos
Biomarcadores Tumorais/análise , Cromatografia Gasosa/instrumentação , Eletroquímica/instrumentação , Ácido Homovanílico/análise , Neuroblastoma/diagnóstico , Silício , Transdutores , Ácido Vanilmandélico/análise , Cromatografia Gasosa/métodos , Eletroquímica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Miniaturização
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