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ABSTRACT: Brain-Computer Interfaces (BCIs) are systems which can provide communication and environmental control to people with severe neuromuscular diseases. The current study proposes a new BCI-based method for psychometric assessment when traditional or computerized testing cannot be used owing to the subject's output impairment. This administration protocol was based on, and validated against, a widely used clinical test (Raven Colored Progressive Matrix) in order to verify whether BCI affects the brain in terms of cognitive resource with a misstatement result. The operating protocol was structured into two phases: phase 1 was aimed at configuring the BCI system on the subject's features and train him/her to use it; during phase 2 the BCI system was reconfigured and the test performed. A step-by-step checking procedure was adopted to verify progressive inclusion/exclusion criteria and the underpinning variables. The protocol was validated on 19 healthy subjects and the BCI-based administration was compared with a paper-based administration. The results obtained by both methods were correlated as known for traditional assessment of a similarly culture free and reasoning based test. Although our findings need to be validated on pathological participants, in our healthy population the BCI-based administration did not affect performance and added a further control of the response due to the several variables included and analyzed by the computerized task.
Journal of neuroscience methods 07/2011; 201(1):239-50. · 2.30 Impact Factor
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ABSTRACT: This paper presents an automated method for relevant frequency bands identification to be used in a left/right hand motor imagery based Brain Computer Interface system. The adopted optimization method aimed at maximizing the ratio between the mutual information and the error rate obtained using a Regularized Linear Discriminant Analysis (RLDA) based classifier and band-specific amplitude modulated envelopes as features. The search problem was handled by a genetic algorithm starting from an initial population determined on the basis of a-priori mu and beta relevant frequency bands identified by means of a standard power spectral density analysis between the idle and the left/right imagery data subset.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2007; 2007:2512-5.
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ABSTRACT: This paper presents and discusses the realization and the performances of a wearable system for EEG-based BCI applications. The system (called Kimera) consists of a two-layer hardware architecture (the wireless acquisition and transmission board based on a BluetoothregARM chip, and a low power miniaturized biosignal acquisition analog front end) together with a software suite (called Bellerophonte) for the graphic user interface management, protocol execution, data recording, transmission and processing. The implemented BCI system was based on the SSVEP protocol, applied to a two state selection by using standards display/monitor with a couple of high efficiency LEDs. The frequency features of the signal were computed and used in the intention detection. The BCI algorithm is based on a supervised classifier implemented through a multi-class canonical discriminant analysis (CDA) with a continuous real-time feedback based on the mahalanobis distance parameter. Five healthy subjects participated in the first phase for a preliminary device validation. The obtained results are very interesting and promising, being lined out to the most recent performance reported in literature with a significant improvement both in system and in classification capabilities. The user-friendliness and low cost of the Kimera & Bellerophonte platform make it suitable for the development of home BCI applications
Engineering in Medicine and Biology Society, 2005. IEEE-EMBS 2005. 27th Annual International Conference of the; 02/2006
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ABSTRACT: This paper discusses the development of a four command BCI system. This system is composed of a wearable electroencephalogram acquisition unit interfaced to a computer by a wireless Bluetooth (BT) connection. The implemented system relies on the steady-state visual evoked potential (SSVEP) protocol applied to a four selection system. In order to achieve the maximum reliability against false positives a five class classifier was used considering the idle state as an independent class. In order to maximize the usability of the system a two channel solution was tested and adopted. The BCI algorithm was based on a supervised multi-class classifier implemented by combining different binary regularized linear discriminant analysis (RLDA) classifiers. The biofeedback was evaluated by combining the resultant time signed distance with quality index related to the number of coherent identification obtained with the one-vs-all approach.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2006; 1:1264-7.
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ABSTRACT: In this study we explored the possibility to realize a low power device for Cardiac Output continuous monitoring based on impedance cardiography technique. We assessed the possibility to develop a system able to record data allow an intra-subjective analysis based on the daily variations of this measure. The device was able to acquire and to send signals using a wireless Bluetooth transmission. The electronic circuit was designed in order to minimize power consumption, dimension and weight. The reported results were interesting for what concerns the power consumption and then noise level. In this way was obtained a wearable device that will permit to define specific clinical protocols based on continuous monitoring of the Cardiac Output signal.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2006; 1:5968-71.
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ABSTRACT: 1. This study investigated the effect of acute (2 days) and chronic (14 days) treatment with a selective inhibitor of noradrenaline uptake, reboxetine (10 mg kg(-1) day(-1)) by osmotic pumps, on extracellular noradrenaline and the sensitivity of alpha(2)-adrenoceptors in the prefrontal cortex of rats. 2. The effect of continuous infusion of reboxetine for 14 days on cortical extracellular noradrenaline was significantly higher (599% of vehicle levels) than after 2 days (263% of vehicle levels). 3. Brain concentrations of reboxetine after 2 and 14 days of infusion were 37.9+/-17.8 and 37.1+/-7.7 ng g(-1), respectively. 4. Reboxetine infused for 2 and 14 days significantly increased extracellular dopamine in the prefrontal cortex, to a similar extent (257 and 342% of vehicle levels, respectively), whereas extracellular 5-HT was not modified by either treatment. 5. Clonidine (10 and 30 microg kg(-1) i.p.) reduced cortical extracellular noradrenaline similarly in animals treated with reboxetine or vehicle for 2 days whereas the effects in rats infused with reboxetine for 14 days were markedly less than in vehicle-treated animals. 6. Clonidine (0.05 and 0.2 microM), infused through the dialysis probe into the prefrontal cortex, reduced cortical extracellular noradrenaline much less in rats treated with reboxetine for 14 days than in vehicle-treated animals. 7. Reboxetine's effect on extracellular noradrenaline in the prefrontal cortex was greater after chronic treatment and could be associated with desensitization of terminal alpha(2)-adrenoceptors that normally serve to inhibit noradrenaline release.
British Journal of Pharmacology 02/2001; 132(1):183-8. · 4.41 Impact Factor
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ABSTRACT: Adaptive phenomena such as desensitization of autoreceptors are considered an important factor in the achievement of therapeutic efficacy of antidepressant drugs after chronic treatment. We have studied whether a chronic treatment with desipramine had a greater effect than a single dose on the extracellular concentrations of noradrenaline in the dorsal hippocampus. Administration of 10 mg/kg i.p. desipramine once daily for 14 days significantly raised the basal extracellular noradrenaline in the dorsal hippocampus 24 h but not 48 h after the last drug injection. A challenge dose of desipramine increased extracellular noradrenaline in rats treated chronically with vehicle and desipramine. The effect was significantly higher in rats treated chronically with desipramine 48 h but not 24 h after the last injection. An intraperitoneal administration of the alpha2-adrenoceptor agonist clonidine at the dose of 10 microg/kg significantly reduced extracellular noradrenaline in the control group but not in animals chronically treated with desipramine whereas 30 microg/kg clonidine produced a similar decrease in both groups. Three concentrations of clonidine (0.05, 0.5 and 1 microM) infused into the hippocampus significantly reduced extracellular noradrenaline to a similar extent in rats chronically treated with saline or desipramine. Fourty-eight hours after the last injection of the chronic treatment, [3H]RX-821002 binding to alpha2-adrenoceptors in the rat locus coeruleus measured by autoradiography was not significantly modified. A slight (17%) but significant decrease of neuronal uptake of [3H]noradrenaline was found in synaptosome preparations from dorsal hippocampus of rats chronically treated with desipramine, but this was likely due to a decrease in affinity. The results suggest that a repeated treatment with desipramine (10 mg/kg i.p. once daily for 14 days) facilitates its effect on extracellular noradrenaline in the dorsal hippocampus and induces adaptive changes probably involving desensitization of alpha2-adrenoceptors, with no changes in their density, on noradrenergic neurons in the locus coeruleus.
Archiv für Experimentelle Pathologie und Pharmakologie 02/2001; 363(1):66-72. · 2.65 Impact Factor
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ABSTRACT: 1 The effect of reboxetine, a novel antidepressant drug that potently and selectively inhibits neuronal noradrenaline (NA) uptake, on brain extracellular monoamines was studied by microdialysis. 2 Fifteen mg kg-1 i.p. reboxetine raised extracellular NA in the frontal cortex (by 242%) and dorsal hippocampus (by 240%). 3 Idazoxan (1 mg kg-1 s.c.), given 60 min after 15 mg kg-1 reboxetine, markedly potentiated the effect on extracellular NA in the frontal cortex (by 1580%) and dorsal hippocampus (by 1360%), but had no effect by itself. 4 Twenty-four hours after the last injection of a chronic schedule (15 mg kg-1 i.p. once daily for 14 days) reboxetine had no effect on basal extracellular concentrations of NA in the dorsal hippocampus and a challenge dose of reboxetine (15 mg kg-1) raised extracellular NA similarly in rats treated chronically with reboxetine (by 353%) and saline (by 425%). 5 Ten and 20 microg kg-1 i.p. clonidine dose-dependently reduced hippocampal extracellular NA similarly in rats given chronic reboxetine (by 32% and 57%) and saline (by 42% and 56%). 6 Extracellular concentrations of dopamine and 5-HT in the striatum were similar in rats treated chronically with reboxetine and saline. A challenge dose of reboxetine (15 mg kg-1) had no effect on striatal extracellular dopamine and slightly increased striatal extracellular 5-HT to a similar extent in rats treated chronically with reboxetine (by 137%) and saline (by 142%). 7 The results suggest that combining reboxetine with an alpha2-adrenoceptor antagonist may facilitate its antidepressant activity. Repeated treatment confirmed that reboxetine is fairly selective for the noradrenergic system but provided no evidence of adaptive changes in that system that could facilitate its effect on extracellular NA.
British Journal of Pharmacology 12/1999; 128(6):1332-8. · 4.41 Impact Factor
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ABSTRACT: This work aimed at developing a BCI driven application for the control of a commercial home automation system. The application was developed using the BCI framework proposed by the SensibiLab Laboratories (Politecnico di Milano) and interfaced with a four command SSVEP based system. A specific software module was implemented in order to provide an interaction layer with an home automation system. A MyHome® gateway was provided by BTicino spa (Erba, Italy) and a basic demonstrator was set-up in our laboratory. The standard physical communication layer of the adopted gateway is RS-232 and, in order to maximize the ease of installation, a specific RS-232 to Bluetooth module was designed. The Application layer was implemented using the OpenWebNet® language proposed by BTicino. Although the current demonstrator supports only a few light-point and some auxiliary devices, the software module supports all the options provided by the home automation system. Six healthy subjects whose ability to use the SSVEP system was already assessed were able to control the demonstrator.
