@article{Balocco2012,
author = {Carla Balocco and Virginia Gori and Enrico Marmonti and Luca Citi},
title = {Building-plant system energy sustainability. An approach for transient
thermal performance analysis},
journal = {Energy and Buildings},
year = {2012},
volume = {49},
pages = {443--453},
month = jun,
abstract = {The aim of this research is to investigate the thermophysical behaviour
of building envelope multi-layer components and assess the whole
building-plant response. The investigation was carried out in two
different phases. The first phase concerned the study of the dynamic
response of building envelope multi-layer components, by providing
an improved implementation of the present European Standard UNI EN
ISO 13786:2008. The proposed method allows one to determine the transient
thermophysical performance of opaque building components that are
associated with a thermal zone maintained at constant or variable
air temperature. The variable internal air temperature can be associated
with experimental data. The second phase consisted of a transient
analysis of the above thermal zone with a conditioning plant working.
The building plant simulations were carried out by EnergyPlus software.
The method proposed, based on European standards, is particularly
useful in the perspective of the Certification of the Energy Performance
of the building-plant system, required by the European Union. It
can provide a useful tool for developing an abacus of different envelope
multi-layer component performances in order to support design choices.},
check = {2012.09.26},
doi = {10.1016/j.enbuild.2012.02.048},
owner = {lciti},
timestamp = {2012.03.28}
}
@article{Citi2012DetectCorrectErronBeats,
author = {Luca Citi and Emery N Brown and Riccardo Barbieri},
title = {A real-time automated point-process method for the detection and
correction of erroneous and ectopic heartbeats.},
journal = {IEEE Transactions on Biomedical Engineering},
year = {2012},
volume = {59},
pages = {2828--2837},
number = {10},
month = oct,
abstract = {The presence of recurring arrhythmic events (also known as cardiac
dysrhythmia or irregular heartbeats), as well as erroneous beat detection
due to low signal quality, significantly affects estimation of both
time and frequency domain indices of heart rate variability (HRV).
A reliable, real-time classification and correction of ECG-derived
heartbeats is a necessary prerequisite for an accurate online monitoring
of HRV and cardiovascular control. We have developed a novel point-process-based
method for real-time R-R interval error detection and correction.
Given an R-wave event, we assume that the length of the next R-R
interval follows a physiologically motivated, time-varying inverse
Gaussian probability distribution. We then devise an instantaneous
automated detection and correction procedure for erroneous and arrhythmic
beats by using the information on the probability of occurrence of
the observed beat provided by the model. We test our algorithm over
two datasets from the PhysioNet archive. The Fantasia normal rhythm
database is artificially corrupted with known erroneous beats to
test both the detection procedure and correction procedure. The benchmark
MIT-BIH Arrhythmia database is further considered to test the detection
procedure of real arrhythmic events and compare it with results from
previously published algorithms. Our automated algorithm represents
an improvement over previous procedures, with best specificity for
the detection of correct beats, as well as highest sensitivity to
missed and extra beats, artificially misplaced beats, and for real
arrhythmic events. A near-optimal heartbeat classification and correction,
together with the ability to adapt to time-varying changes of heartbeat
dynamics in an online fashion, may provide a solid base for building
a more reliable real-time HRV monitoring device.},
check = {2012.09.26},
doi = {10.1109/TBME.2012.2211356},
owner = {lciti},
pmid = {22875239},
timestamp = {2012.09.26}
}
@article{Citi2008UseWavDenAndSpikeSortingProcessENGSignals,
author = {Luca Citi and Jacopo Carpaneto and Ken Yoshida and Klaus-Peter Hoffmann
and Klaus Peter Koch and Paolo Dario and Silvestro Micera},
title = {On the use of wavelet denoising and spike sorting techniques to process
electroneurographic signals recorded using intraneural electrodes.},
journal = {Journal of Neuroscience Methods},
year = {2008},
volume = {172},
pages = {294--302},
number = {2},
month = jul,
abstract = {Among the possible interfaces with the peripheral nervous system (PNS),
intraneural electrodes represent an interesting solution for their
potential advantages such as the possibility of extracting spikes
from electroneurographic (ENG) signals. Their use could increase
the precision and the amount of information which can be detected
with respect to other processing methods. In this study, in order
to verify this assumption, thin-film longitudinal intrafascicular
electrodes (tfLIFE) were implanted in the sciatic nerve of rabbits.
Various sensory stimuli were applied to the hind limb of the animal
and the elicited ENG signals were recorded using the tfLIFEs. These
signals were processed to determine whether the different types of
information can be decoded. Signals were wavelet denoised and spike
sorted. Support vector machines were trained to use the spike waveforms
found to infer the stimulus applied to the rabbit. This approach
was also compared with previously used ENG-processing methods. The
results indicate that the combination of wavelet denoising and spike
sorting techniques can increase the amount of information extractable
from ENG signals recorded with intraneural electrodes. This strategy
could allow the development of more effective closed-loop neuroprostheses
and hybrid bionic systems connecting the human nervous system with
artificial devices.},
aka = {#Citi2007UseLIFEsIdentifyNeuralInformation#},
check = {2011.01.12},
doi = {10.1016/j.jneumeth.2008.04.025},
institution = {ARTS and CRIM Labs, Scuola Superiore Sant'Anna, Pisa, Italy.},
owner = {lciti},
pii = {S0165-0270(08)00258-6},
pmid = {18534683},
timestamp = {2008.09.07},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2008WaveletDenoisingSpikeSorting.pdf}
}
@article{Citi2010DocumenModelExploitP300AmplVar,
author = {Luca Citi and Riccardo Poli and Caterina Cinel},
title = {Documenting, modelling and exploiting {P300} amplitude changes due
to variable target delays in {D}onchin's speller.},
journal = {Journal of Neural Engineering},
year = {2010},
volume = {7},
pages = {056006},
number = {5},
month = oct,
abstract = {The P300 is an endogenous event-related potential (ERP) that is naturally
elicited by rare and significant external stimuli. P300s are used
increasingly frequently in brain-computer interfaces (BCIs) because
the users of ERP-based BCIs need no special training. However, P300
waves are hard to detect and, therefore, multiple target stimulus
presentations are needed before an interface can make a reliable
decision. While significant improvements have been made in the detection
of P300s, no particular attention has been paid to the variability
in shape and timing of P300 waves in BCIs. In this paper we start
filling this gap by documenting, modelling and exploiting a modulation
in the amplitude of P300s related to the number of non-targets preceding
a target in a Donchin speller. The basic idea in our approach is
to use an appropriately weighted average of the responses produced
by a classifier during multiple stimulus presentations, instead of
the traditional plain average. This makes it possible to weigh more
heavily events that are likely to be more informative, thereby increasing
the accuracy of classification. The optimal weights are determined
through a mathematical model that precisely estimates the accuracy
of our speller as well as the expected performance improvement w.r.t.
the traditional approach. Tests with two independent datasets show
that our approach provides a marked statistically significant improvement
in accuracy over the top-performing algorithm presented in the literature
to date. The method and the theoretical models we propose are general
and can easily be used in other P300-based BCIs with minimal changes.},
check = {2011.01.12},
doi = {10.1088/1741-2560/7/5/056006},
institution = {Brain-Computer Interfaces Lab, School of Computer Science and Electronic
Engineering,University of Essex, Colchester CO4 3SQ, UK. lciti@neurostat.mit.edu},
owner = {lciti},
pii = {S1741-2560(10)59095-5},
pmid = {20811092},
timestamp = {2010.10.27},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2010DocumenModelExploitP300AmplVar.pdf}
}
@article{Citi2008P300BCIMouseGenetOptimAnalogueContr,
author = {Luca Citi and Riccardo Poli and Francisco Sepulveda and Caterina
Cinel},
title = {P300-based {BCI} Mouse with Genetically-optimized Analogue Control},
journal = {IEEE Transactions on Neural System and Rehabilitation Engineering},
year = {2008},
volume = {16},
pages = {51--61},
number = {1},
month = feb,
abstract = {In this paper we propose a brain-computer interface (BCI) mouse based
on P300 waves in electroencephalogram (EEG) signals. The system is
analogue in that at no point a binary decision is made as to whether
or not a P300 was actually produced in response to the stimuli. Instead,
the 2-D motion of the pointer on the screen, using a novel BCI paradigm,
is controlled by directly combining the amplitudes of the output
produced by a filter in the presence of different stimuli. This filter
and the features to be combined within it are optimised by an evolutionary
algorithm.},
check = {2011.01.12},
doi = {10.1109/TNSRE.2007.913184},
institution = {IMT Institute for Advanced Studies, 55100 Lucca, Italy. lciti@essex.ac.uk},
keywords = {Adult; Algorithms; Brain, physiology; Computer Graphics; Electrodes;
Electroencephalography; Event-Related Potentials, P300, genetics/physiology;
Female; Humans; Male; Psychomotor Performance, physiology; User-Computer
Interface},
owner = {lciti},
pmid = {18303806},
timestamp = {2006.11.26},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2008P300BasedBCIMouse.pdf}
}
@article{Citi2009MatchingBMIPerfSpaceAppl,
author = {Luca Citi and Oliver Tonet and Martina Marinelli},
title = {Matching {Brain-Machine Interface} performance to space applications},
journal = {International Review of Neurobiology},
year = {2009},
volume = {86},
pages = {199--212},
month = jul,
abstract = {A brain-machine interface (BMI) is a particular class of human-machine
interface (HMI). BMIs have so far been studied mostly as a communication
means for people who have little or no voluntary control of muscle
activity. For able-bodied users, such as astronauts, a BMI would
only be practical if conceived as an augmenting interface. A method
is presented for pointing out effective combinations of HMIs and
applications of robotics and automation to space. Latency and throughput
are selected as performance measures for a hybrid bionic system (HBS),
that is, the combination of a user, a device, and a HMI. We classify
and briefly describe HMIs and space applications and then compare
the performance of classes of interfaces with the requirements of
classes of applications, both in terms of latency and throughput.
Regions of overlap correspond to effective combinations. Devices
requiring simpler control, such as a rover, a robotic camera, or
environmental controls are suitable to be driven by means of BMI
technology. Free flyers and other devices with six degrees of freedom
can be controlled, but only at low-interactivity levels. More demanding
applications require conventional interfaces, although they could
be controlled by BMIs once the same levels of performance as currently
recorded in animal experiments are attained. Robotic arms and manipulators
could be the next frontier for noninvasive BMIs. Integrating smart
controllers in HBSs could improve interactivity and boost the use
of BMI technology in space applications.},
check = {2011.01.12},
doi = {10.1016/S0074-7742(09)86015-7},
institution = {School of Computer Science and Electronic Engineering, University
of Essex, Wivenhoe Park, CO4 3SQ Colchester, UK.},
keywords = {Brain, physiology; Communication Aids for Disabled; Humans; Man-Machine
Systems; Psychomotor Performance, physiology; Reaction Time, physiology;
Space Flight; User-Computer Interface},
owner = {lciti},
pii = {S0074-7742(09)86015-7},
pmid = {19608001},
timestamp = {2009.05.13},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2009MatchingBMIPerfSpaceAppl.pdf}
}
@article{Menon2009ProspectsBMISpaceControl,
author = {Carlo Menon and Cristina de Negueruela and del R. Mill\'an, Jos\'e
and Oliver Tonet and Federico Carpi and Michael Broschart and Pierre
Ferrez and Anna Buttfield and Franca Tecchio and Francisco Sepulveda
and Luca Citi and Cecilia Laschi and Mario Tombini and Paolo Dario
and Paolo Maria Rossini and Danilo De Rossi},
title = {Prospects of brain-machine interfaces for space system control},
journal = {Acta Astronautica},
year = {2009},
volume = {64},
pages = {448--456},
number = {4},
month = feb,
abstract = {The dream of controlling and guiding computer-based systems using
human brain signals has slowly but steadily become a reality. The
available technology allows real-time implementation of systems that
measure neuronal activity, convert their signals, and translate their
output for the purpose of controlling mechanical and electronic systems.
This paper describes the state of the art of non-invasive brain-machine
interfaces (BMIs) and critically investigates both the current technological
limits and the future potential that BMIs have for space applications.
We present an assessment of the advantages that BMIs can provide
and justify the preferred candidate concepts for space applications
together with a vision of future directions for their implementation.},
check = {2011.08.17},
doi = {10.1016/j.actaastro.2008.09.008},
issn = {0094-5765},
keywords = {Brain},
owner = {lciti},
timestamp = {2010.10.28},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Menon2009ProspectsBMISpaceControl.pdf}
}
@article{Micera2010DecodingFromIntraneuralElect,
author = {Micera, S. and Citi, L. and Rigosa, J. and Carpaneto, J. and Raspopovic,
S. and Di Pino, G. and Rossini, L. and Yoshida, K. and Denaro, L.
and Dario, P. and Rossini, P.M.},
title = {Decoding Information From Neural Signals Recorded Using Intraneural
Electrodes: Toward the Development of a Neurocontrolled Hand Prosthesis},
journal = {Proceedings of the IEEE},
year = {2010},
volume = {98},
pages = {407 -417},
number = {3},
month = mar,
abstract = {The possibility of controlling dexterous hand prostheses by using
a direct connection with the nervous system is particularly interesting
for the significant improvement of the quality of life of patients,
which can derive from this achievement. Among the various approaches,
peripheral nerve based intrafascicular electrodes are excellent neural
interface candidates, representing an excellent compromise between
high selectivity and relatively low invasiveness. Moreover, this
approach has undergone preliminary testing in human volunteers and
has shown promise. In this paper, we investigate whether the use
of intrafascicular electrodes can be used to decode multiple sensory
and motor information channels with the aim to develop a finite state
algorithm that may be employed to control neuroprostheses and neurocontrolled
hand prostheses. The results achieved both in animal and human experiments
show that the combination of multiple sites recordings and advanced
signal processing techniques (such as wavelet denoising and spike
sorting algorithms) can be used to identify both sensory stimuli
(in animal models) and motor commands (in a human volunteer). These
findings have interesting implications, which should be investigated
in future experiments.},
check = {2010.10.27},
doi = {10.1109/JPROC.2009.2038726},
issn = {0018-9219},
keywords = {animal models;decoding information;dexterous hand prosthesis;electroneurographic
signals;finite state algorithm;hybrid bionic systems;intrafascicular
electrodes;intraneural electrodes;motor information channels;multiple
sensory;nervous system;neural interface;neural signal recording;neurocontrolled
hand prosthesis;peripheral nerve;sensory stimuli;signal processing
techniques;spike sorting algorithms;wavelet denoising;biomedical
electrodes;brain models;decoding;electroencephalography;electromyography;mechanoception;medical
robotics;medical signal processing;neurophysiology;prosthetics;sensory
aids;signal denoising;sorting;wavelet transforms;},
owner = {lciti},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Micera2010DecodingFromIntraneuralElect.pdf}
}
@article{Micera2008UseIntranPeriphInterfContrCybernHandProstAmp,
author = {Silvestro Micera and Xavier Navarro and Jacopo Carpaneto and Luca
Citi and Oliver Tonet and Rossini, Paolo Maria and Carrozza, Maria
Chiara and Klaus-Peter Hoffmann and M. Viv\'o and Ken Yoshida and
Paolo Dario},
title = {On the use of longitudinal intrafascicular peripheral interfaces
for the control of cybernetic hand prostheses in amputees.},
journal = {IEEE Transactions on Neural System and Rehabilitation Engineering},
year = {2008},
volume = {16},
pages = {453--472},
number = {5},
month = oct,
abstract = {Significant strides have been recently made to develop highly sensorized
cybernetic prostheses aimed at restoring sensorimotor limb functions
to those who have lost them because of a traumatic event (amputation).
In these cases, one of the main goals is to create a bidirectional
link between the artificial devices (e.g., robotic hands, arms, or
legs) and the nervous system. Several human-machine interfaces (HMIs)
are currently used to this aim. Among them, interfaces with the peripheral
nervous system and in particular longitudinal intrafascicular electrodes
can be a promising solution able to improve the current situation.
In this paper, the potentials and limits of the use of this interface
to control robotic devices are presented. Specific information is
provided on: 1) the neurophysiological bases for the use peripheral
nerve interfaces; 2) a comparison of the potentials of the different
peripheral neural interfaces; 3) the possibility of extracting and
appropriately interpreting the neural code for motor commands and
of delivering sensory feedback by stimulating afferent fibers by
using longitudinal intrafascicular electrodes; 4) a preliminary comparative
analysis of the performance of this approach with the ones of others
HMIs; 5) the open issues which have to be addressed for a chronic
usability of this approach.},
check = {2010.10.27},
doi = {10.1109/TNSRE.2008.2006207},
institution = {ARTS and CRIM Laboratories, Scuola Superiore SantAnna, 56127 Pisa,
Italy. micera@sssup.it},
keywords = {Amputees, rehabilitation; Cybernetics, instrumentation; Electromyography,
instrumentation; Equipment Design; Equipment Failure Analysis; Hand;
Humans; Peripheral Nerves, physiology; Prostheses and Implants; Robotics,
instrumentation},
owner = {lciti},
pmid = {18990649},
timestamp = {2006.11.27}
}
@article{Micera2011DecodingGraspingInfoFronNeuralignals,
author = {Silvestro Micera and Paolo M Rossini and Jacopo Rigosa and Luca Citi
and Jacopo Carpaneto and Stanisa Raspopovic and Mario Tombini and
Christian Cipriani and Giovanni Assenza and Maria C Carrozza and
Klaus-Peter Hoffmann and Ken Yoshida and Xavier Navarro and Paolo
Dario},
title = {Decoding of grasping information from neural signals recorded using
peripheral intrafascicular interfaces.},
journal = {Journal of Neuroengineering and Rehabilitation},
year = {2011},
volume = {8},
pages = {53},
number = {1},
month = sep,
abstract = {BACKGROUND: The restoration of complex hand functions by creating
a novel bidirectional link between the nervous system and a dexterous
hand prosthesis is currently pursued by several groups. This connection
must be fast, intuitive, and quite natural to allow an effective
bidirectional flow of information between the user's nervous system
and the smart artificial device. This goal can be achieved with several
approaches and among them, the use of implantable interfaces with
the peripheral nervous system, namely intrafascicular electrodes,
is considered particularly interesting. METHODS: Thin-film longitudinal
intra-fascicular electrodes were implanted in the median and ulnar
nerves of an amputee's residuum during a four-week trial. The possibility
of decoding motor commands suitable to control a dexterous hand prosthesis
was investigated for the first time in this research field by implementing
a spike sorting and classification algorithm. RESULTS: The results
showed that motor information (e.g., grip types and single finger
movements) could be extracted with classification accuracy around
85 (for three classes plus rest) and that the user could improve
his ability to govern motor commands over time as shown by the improved
discrimination ability of our classification algorithm. CONCLUSIONS:
These results open up new and promising possibilities for the development
of a neuro-controlled hand prosthesis.},
check = {2011.09.07},
doi = {10.1186/1743-0003-8-53},
owner = {lciti},
pii = {1743-0003-8-53},
pmid = {21892926},
timestamp = {2011.09.07}
}
@article{Poli2010ReactionTimeBinningForIncrResolvPowerERPAverages,
author = {Riccardo Poli and Caterina Cinel and Luca Citi and Francisco Sepulveda},
title = {Reaction-time binning: a simple method for increasing the resolving
power of ERP averages.},
journal = {Psychophysiology},
year = {2010},
volume = {47},
pages = {467--485},
number = {3},
month = may,
abstract = {Stimulus-locked, response-locked, and ERP-locked averaging are effective
methods for reducing artifacts in ERP analysis. However, they suffer
from a magnifying-glass effect: they increase the resolution of specific
ERPs at the cost of blurring other ERPs. Here we propose an extremely
simple technique-binning trials based on response times and then
averaging-which can significantly alleviate the problems of other
averaging methods. We have empirically evaluated the technique in
an experiment where the task requires detecting a target in the presence
of distractors. We have also studied the signal-to-noise ratio and
the resolving power of averages with and without binning. Results
indicate that the method produces clearer representations of ERPs
than either stimulus-locked and response-locked averaging, revealing
finer details of ERPs and helping in the evaluation of the amplitude
and latency of ERP waves. The method is applicable to within-subject
and between-subject averages.},
check = {2011.08.17},
doi = {10.1111/j.1469-8986.2009.00959.x},
institution = {Brain Computer Interfaces Laboratory, School of Computer Science
and Electronic Engineering, University of Essex, Colchester, 304
ESQ, UK. rpoli@essex.ac.uk},
keywords = {Adult; Algorithms; Artifacts; Data Interpretation, Statistical; Electroencephalography,
statistics /&/ numerical data; Evoked Potentials, physiology; Female;
Humans; Male; Models, Statistical; Photic Stimulation; Psychomotor
Performance, physiology; Reaction Time, physiology; Sample Size;
Young Adult},
language = {eng},
medline-pst = {ppublish},
owner = {lciti},
pii = {PSYP959},
pmid = {20070576},
timestamp = {2010.10.27},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Poli2010ReactionTimeBinningForIncrResolvPowerERPAverages.pdf}
}
@article{Poli2009AnalogueEvolutionaryBCI,
author = {Poli, Riccardo and Citi, Luca and Sepulveda, Francisco and Cinel,
Caterina},
title = {Analogue evolutionary brain computer interfaces},
journal = {IEEE Computational Intelligence Magazine},
year = {2009},
volume = {4},
pages = {27 -31},
number = {4},
month = nov,
abstract = {The keyboard is a device that, provides an interface that is reliable
but also very unnatural. The mouse is only slightly less primitive,
being an electro-mechanical transducer of musculoskeletal movement.
Both have been with us for decades, yet they are unusable for people
with severe musculoskeletal disorders and are themselves known causes
of work-related upper-limb and back disorders, both hugely widespread
problems. It will be a major contribution to computer interface technology
to replace mouse and keyboard with brain-computer interfaces (BCIs)
capable of directly interpreting the desires and intentions of computer
users. In this article we describe the approach, results and promising
new research directions in the realization of BCIs, with particular
reference to a 2D pointing device. Three features characterize the
approach. Firstly, BCI is logically analogue, second is the use of
evolutionary algorithms, and the third feature is its interdisciplinarity.},
check = {2010.10.27},
doi = {10.1109/MCI.2009.934563},
issn = {1556-603X},
keywords = {2D pointing device;BCI approach;back disorders;brain computer interfaces;evolutionary
algorithms;logically analogue system;musculoskeletal disorders;work-related
upper-limb disorder;brain-computer interfaces;evolutionary computation;human
computer interaction;},
owner = {lciti}
}
@article{Poli2009MemoryWithMemoryGP,
author = {Poli, Riccardo and McPhee, Nicholas Freitag and Citi, Luca and Crane,
Ellery},
title = {Memory with memory in genetic programming},
journal = {Journal of Artificial Evolution and Applications},
year = {2009},
volume = {2009},
pages = {1--16},
month = jan,
abstract = {We introduce Memory with Memory Genetic Programming (MwM-GP), where
we use soft assignments and soft return operations. Instead of having
the new value completely overwrite the old value of registers or
memory, soft assignments combine such values. Similarly, in soft
return operations the value of a function node is a blend between
the result of a calculation and previously returned results. In extensive
empirical tests, MwM-GP almost always does as well as traditional
GP, while significantly outperforming it in several cases. MwM-GP
also tends to be far more consistent than traditional GP. The data
suggest that MwM-GP works by successively refining an approximate
solution to the target problem and that it is much less likely to
have truly ineffective code. MwM-GP can continue to improve over
time, but it is less likely to get the sort of exact solution that
one might find with traditional GP.},
check = {2010.10.28},
doi = {10.1155/2009/570606},
issn = {1687-6229},
owner = {lciti},
timestamp = {2010.10.28}
}
@article{Rossini2010DoubleNerveIntranInterfHumanAmputee,
author = {Paolo M Rossini and Silvestro Micera and Antonella Benvenuto and
Jacopo Carpaneto and Giuseppe Cavallo and Luca Citi and Christian
Cipriani and Luca Denaro and Vincenzo Denaro and Giovanni Di Pino
and Florinda Ferreri and Eugenio Guglielmelli and Klaus-Peter Hoffmann
and Stanisa Raspopovic and Jacopo Rigosa and Luca Rossini and Mario
Tombini and Paolo Dario},
title = {Double nerve intraneural interface implant on a human amputee for
robotic hand control.},
journal = {Clinical Neurophysiology},
year = {2010},
volume = {121},
pages = {777--783},
number = {5},
month = may,
abstract = {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.},
check = {2011.01.12},
doi = {10.1016/j.clinph.2010.01.001},
institution = {Dept. of Neurology, University Campus Bio-Medico, Rome, Italy. p.rossini@unicampus.it},
keywords = {Adult; Amputation, Traumatic, complications; Amputees; Artificial
Limbs; Computer Systems; Electric Stimulation; Electrodes, Implanted;
Hand; Humans; Internal-External Control; Male; Median Nerve, physiopathology/surgery;
Movement; Nerve Fibers; Neuronal Plasticity; Phantom Limb, etiology/physiopathology/surgery;
Robotics; Sensation; Transcranial Magnetic Stimulation; Ulnar Nerve,
physiopathology/surgery},
language = {eng},
medline-pst = {ppublish},
owner = {lciti},
pii = {S1388-2457(10)00003-9},
pmid = {20110193},
timestamp = {2010.10.27},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Rossini2010DoubleNerveIntranInterfHumanAmputee.pdf}
}
@article{Salvaris2012NovelProtocolsP300BCI,
author = {Salvaris, Mathew and Cinel, Caterina and Citi, Luca and Poli, Riccardo},
title = {Novel Protocols for {P300}-Based Brain-Computer Interfaces},
journal = {IEEE Transactions on Neural System and Rehabilitation Engineering},
year = {2012},
volume = {20},
pages = {8--17},
number = {1},
month = jan,
abstract = {The oddball protocol is often used in Brain- Computer Interfaces (BCIs)
to induce P300 ERPs, although, recently, some issues have been shown
to detrimentally effect its performance. In this paper, we study
a new periodic protocol and explore whether it can compete with the
standard oddball protocol within the context of a BCI mouse. We found
that the new protocol consistently and significantly outperforms
the standard oddball protocol in relation to information transfer
rates (33 bits/min for the former and 22 bits/min for the latter,
measured at 90% accuracy) as well as P300 amplitudes. Furthermore,
we performed a comparison of two periodic protocols with two less
conventional oddball-like protocols that reveals the importance of
the interactions between task and sequence in determining the success
of a protocol.},
check = {2012.09.26},
doi = {10.1109/TNSRE.2011.2174463},
owner = {lciti},
timestamp = {2012.01.10},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Salvaris2012NovelProtocolsP300BCI.pdf}
}
@article{Tombini2011CombinedAnalysisEEGENGRoboticHand,
author = {Mario Tombini and Jacopo Rigosa and Filippo Zappasodi and Camillo
Porcaro and Luca Citi and Jacopo Carpaneto and Paolo Maria Rossini
and Silvestro Micera},
title = {Combined Analysis of Cortical ({EEG}) and Nerve Stump Signals Improves
Robotic Hand Control.},
journal = {Neurorehabil Neural Repair},
year = {2012},
volume = {26},
pages = {275--281},
month = jul,
abstract = {BACKGROUND: Interfacing an amputee's upper-extremity stump nerves
to control a robotic hand requires training of the individual and
algorithms to process interactions between cortical and peripheral
signals. OBJECTIVE: To evaluate for the first time whether EEG-driven
analysis of peripheral neural signals as an amputee practices could
improve the classification of motor commands. METHODS: Four thin-film
longitudinal intrafascicular electrodes (tf-LIFEs-4) were implanted
in the median and ulnar nerves of the stump in the distal upper arm
for 4 weeks. Artificial intelligence classifiers were implemented
to analyze LIFE signals recorded while the participant tried to perform
3 different hand and finger movements as pictures representing these
tasks were randomly presented on a screen. In the final week, the
participant was trained to perform the same movements with a robotic
hand prosthesis through modulation of tf-LIFE-4 signals. To improve
the classification performance, an event-related desynchronization/synchronization
(ERD/ERS) procedure was applied to EEG data to identify the exact
timing of each motor command. RESULTS: Real-time control of neural
(motor) output was achieved by the participant. By focusing electroneurographic
(ENG) signal analysis in an EEG-driven time window, movement classification
performance improved. After training, the participant regained normal
modulation of background rhythms for movement preparation (\alpha/\beta
band desynchronization) in the sensorimotor area contralateral to
the missing limb. Moreover, coherence analysis found a restored \alpha
band synchronization of Rolandic area with frontal and parietal ipsilateral
regions, similar to that observed in the opposite hemisphere for
movement of the intact hand. Of note, phantom limb pain (PLP) resolved
for several months. CONCLUSIONS: Combining information from both
cortical (EEG) and stump nerve (ENG) signals improved the classification
performance compared with tf-LIFE signals processing alone; training
led to cortical reorganization and mitigation of PLP.},
check = {2012.09.26},
doi = {10.1177/1545968311408919},
owner = {lciti},
pii = {1545968311408919},
pmid = {21730360},
timestamp = {2011.09.07}
}
@article{Tonet2008DefBMIApplicMergingIntPerfDevicRequir,
author = {Oliver Tonet and Martina Marinelli and Luca Citi and Paolo Maria
Rossini and Luca Rossini and Giuseppe Megali and Paolo Dario},
title = {Defining {Brain-Machine Interface} applications by matching interface
performance with device requirements.},
journal = {Journal of Neuroscience Methods},
year = {2008},
volume = {167},
pages = {91--104},
number = {1},
month = jan,
abstract = {Interaction with machines is mediated by human-machine interfaces
(HMIs). Brain-machine interfaces (BMIs) are a particular class of
HMIs and have so far been studied as a communication means for people
who have little or no voluntary control of muscle activity. In this
context, low-performing interfaces can be considered as prosthetic
applications. On the other hand, for able-bodied users, a BMI would
only be practical if conceived as an augmenting interface. In this
paper, a method is introduced for pointing out effective combinations
of interfaces and devices for creating real-world applications. First,
devices for domotics, rehabilitation and assistive robotics, and
their requirements, in terms of throughput and latency, are described.
Second, HMIs are classified and their performance described, still
in terms of throughput and latency. Then device requirements are
matched with performance of available interfaces. Simple rehabilitation
and domotics devices can be easily controlled by means of BMI technology.
Prosthetic hands and wheelchairs are suitable applications but do
not attain optimal interactivity. Regarding humanoid robotics, the
head and the trunk can be controlled by means of BMIs, while other
parts require too much throughput. Robotic arms, which have been
controlled by means of cortical invasive interfaces in animal studies,
could be the next frontier for non-invasive BMIs. Combining smart
controllers with BMIs could improve interactivity and boost BMI applications.},
check = {2011.08.17},
doi = {10.1016/j.jneumeth.2007.03.015},
institution = {CRIM Lab, Scuola Superiore Sant'Anna, Pisa, Italy. oliver.tonet@sssup.it},
keywords = {Brain; Communication Aids for Disabled; Computer Simulation; Electroencephalography;
Feedback; Humans; Man-Machine Systems; Numerical Analysis, Computer-Assisted;
Reaction Time; User-Computer Interface},
owner = {lciti},
pii = {S0165-0270(07)00143-4},
pmid = {17499364},
timestamp = {2008.09.07},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Tonet2008DefBMIApplicMergingIntPerfDevicRequir.pdf}
}
@article{ValenzaCiti2013PointProcNonlinLaguerre,
author = {Valenza, Gaetano and Citi, Luca and Scilingo, Enzo Pasquale and Barbieri,
Riccardo},
title = {Point-Process Nonlinear Models with {L}aguerre and {V}olterra Expansions:
Instantaneous Assessment of Heartbeat Dynamics},
journal = {IEEE Transactions on Signal Processing},
year = {2013},
pages = {(in press)},
abstract = {In the last decades, mathematical modelling and signal processing
techniques have played an important role in the study of cardiovascular
control physiology and heartbeat nonlinear dynamics. In particular,
nonlinear models have been devised for the assessment of the cardiovascular
system by accounting for short-memory second-order nonlinearities.
In this paper, we introduce a novel inverse Gaussian point process
model with Laguerre expansion of the nonlinear Volterra kernels.
Within the model, the second-order nonlinearities also account for
the long-term information given by the past events of the nonstationary
non-Gaussian time series. In addition, the mathematical link to an
equivalent cubic input-output Wiener-Volterra model allows for a
novel instantaneous estimation of the dynamic spectrum, bispectrum
and trispectrum of the considered inter-event intervals. The proposed
framework is tested with synthetic simulations and two experimental
heartbeat interval datasets. Applications on further heterogeneous
datasets such as milling inserts, neural spikes, gait from short
walks, and geyser geologic events are also reported. Results show
that our model improves on previously developed models and, at the
same time, it is able to provide a novel instantaneous characterization
and tracking of the inherent nonlinearity of heartbeat dynamics.},
doi = {10.1109/TSP.2013.2253775},
owner = {lciti},
timestamp = {2013.04.04}
}
@incollection{Citi2013WavDenNeuralSignals,
author = {Luca Citi and Silvestro Micera},
title = {Wavelet denoising and conditioning of neural recordings},
booktitle = {Introduction to Neural Engineering for Motor Rehabilitation},
publisher = {IEEE/Wiley Press},
year = {2013},
editor = {Dario Farina and Winnie Jensen and Metin Akay},
chapter = {9},
check = {2012.12.13},
owner = {lciti},
timestamp = {2012.12.13}
}
@incollection{Citi2010HighSignifAveragesERPViaGP,
author = {Citi, Luca and Poli, Riccardo and Cinel, Caterina},
title = {High-Significance Averages of Event-Related Potential Via Genetic
Programming},
booktitle = {Genetic Programming Theory and Practice VII},
publisher = {Springer US},
year = {2010},
editor = {Riolo, Rick and O'Reilly, Una-May and McConaghy, Trent},
series = {Genetic and Evolutionary Computation},
chapter = {9},
pages = {135-157},
abstract = {In this paper we use register-based genetic programming with memory-with
memory to discover probabilistic membership functions that are used
to divide up data-sets of event-related potentials recorded via EEG
in psycho-physiological experiments based on the corresponding response
times. The objective is to evolve membership functions which lead
to maximising the statistical significance with which true brain
waves can be reconstructed when averaging the trials in each bin.
Results show that GP can significantly improve the fidelity with
which ERP components can be recovered.},
affiliation = {University of Essex School of Computer Science and Electronic Engineering
Wivenhoe Park CO4 3SQ UK},
check = {2010.10.28},
doi = {10.1007/978-1-4419-1626-6_9},
isbn = {978-1-4419-1626-6},
keyword = {Computer Science},
owner = {lciti},
timestamp = {2010.10.28}
}
@inproceedings{Carpaneto2011ActivitiesPNSNeuralInterf,
author = {Carpaneto, Jacopo and Cutrone, Annarita and Bossi, Silvia and Sergi,
Pier Nicola and Citi, Luca and Rigosa, Jacopo and Rossini, Paolo
Maria and Micera, Silvestro},
title = {Activities on {PNS} Neural Interfaces for the Control of Hand Prostheses},
booktitle = {Proceedings of the 33rd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2011},
address = {Boston},
month = sep,
abstract = {The development of interfaces linking the human nervous system with
artificial devices is an important area of research. Several groups
are working on the development of devices able to restore sensory-motor
function in subjects affected by neurological disorders, injuries
or amputations. Neural electrodes implanted in peripheral nervous
system, and in particular intrafascicular electrodes, seem to be
a promising approach for the control of hand prosthesis thanks to
the possibility to selectively access motor and sensory fibers for
decoding motor commands and delivering sensory feedback. In this
paper, activities on the use of PNS interfaces for the control of
hand prosthesis are presented. In particular, the design and feasibility
study of a self-opening neural interface is presented together with
the decoding of ENG signals in one amputee to control a dexterous
hand prosthesis.},
check = {2011.09.07},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Chen2011InstantAssessAutonomicCardiovControlAnesthesia,
author = {Chen, Zhe and Citi, Luca and Purdon, Patrick L and Brown, Emery N
and Barbieri, Riccardo},
title = {Instantaneous Assessment of Autonomic Cardiovascular Control During
General Anesthesia},
booktitle = {Proceedings of the 33rd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2011},
address = {Boston},
month = sep,
abstract = {We present a comprehensive probabilistic point process framework to
estimate and monitor the instantaneous heartbeat dynamics as related
to specific cardiovascular control mechanisms and hemodynamics. Assessment
of the model's statistics is established through the Wiener-Volterra
theory and a multivariate autoregressive (AR) structure. A variety
of instantaneous cardiovascular metrics, such as heart rate (HR),
heart rate variability (HRV), respiratory sinus arrhythmia (RSA),
and baroreceptor-cardiac reflex (BRS), can be rigorously derived
within a parametric framework and instantaneously updated with an
adaptive algorithm. Instantaneous metrics of nonlinearity, such as
the bispectrum of heartbeat intervals, can also be derived. We have
applied the proposed point process framework to experimental recordings
from healthy subjects in order to monitor cardiovascular regulation
under propofol anesthesia. Results reveal interesting dynamic trends
across different pharmacological interventions, confirming the ability
of the algorithm to track important changes in cardiorespiratory
elicited interactions, and pointing at our mathematical approach
as a promising monitoring tool for an accurate, noninvasive assessment
of general anesthesia.},
check = {2011.09.07},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Cinel2004PossSourPercErrorP300,
author = {Caterina Cinel and Riccardo Poli and Luca Citi},
title = {Possible sources of perceptual errors in {P300}-based speller paradigm},
booktitle = {Proceedings of the 2nd International {BCI} Workshop and Training
Course},
year = {2004},
pages = {39--40},
address = {Graz},
month = sep,
abstract = {Some perceptual phenomena can interfere with character identification
in Farwell and Donchin's P300-based speller paradigm: attentional
blink, repetition blindness and other effects caused by attentional
limits. In the paper we discuss these and provide empirical evidence
for one class of perceptual errors.},
check = {2010.10.27},
owner = {lciti},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Cinel2004PossibleSurcesPerceptErrorsP300.pdf}
}
@inproceedings{Citi2012PredictingMortality,
author = {Citi, L. and Barbieri, R.},
title = {{P}hysio{N}et 2012 Challenge: Predicting Mortality of {ICU} Patients
using a Cascaded {SVM-GLM} Paradigm},
booktitle = {Computing in Cardiology},
year = {2012},
address = {Krakow},
month = sep,
__markedentry = {[lciti:]},
abstract = {The focus of the PhysioNet/CinC Challenge 2012 is to develop methods
for patient-specific prediction of in-hospital mortality using general
descriptors recorded at the time of admission to the ICU and up to
37 time-series measurements collected during the first 48 hours after
admission. We developed an algorithm that uses both general descriptors
and time-series measurements to predict the in-hospital death (IHD)
of ICU patients in Event 1, and to provide a probability estimate
of IHD in Event 2. Both aggregated variables and general descriptors
were used as features of quadratic Support Vector Machine (SVM) classifiers.
Six SVMs were trained using, for each one, all the positive examples
plus, in turn, one sixth of the negative examples in the training
set. Finally, a Generalized Linear Model with probit link was used
to predict the probability of IHD for Event 2 using the raw outputs
of the six SVMs as regressors. A positive binary prediction of IHD
for Event 1 was made when the probability estimate was higher than
an optimized threshold. Official final results of the challenge reported
that our entry achieved an Event 2 score of 17.8835, which is the
best score out of the total 23 submissions, and Event 1 score of
0.534454 (second best score).},
check = {2012.12.13},
owner = {lciti},
timestamp = {2012.12.13},
url = {http://cinc.mit.edu/archives/2012/pdf/0257.pdf}
}
@inproceedings{Citi2011InstantMonitoringSleepFragmentPointProcess,
author = {Citi, Luca and Bianchi, Matt T. and Klerman, Elizabeth B. and Barbieri,
Riccardo},
title = {Instantaneous Monitoring of Sleep Fragmentation by Point Process
Heart Rate Variability and Respiratory Dynamics},
booktitle = {Proceedings of the 33rd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2011},
address = {Boston},
month = sep,
abstract = {We present a novel, automatic point-process approach that is able
to provide continuous, instantaneous estimates of heart rate variability
(HRV) and respiratory sinus arrhythmia (RSA) in long duration data
recordings such as those during an entire night of sleep. We analyze
subjects with and without sleep apnea who underwent diagnostic polysomnography.
The proposed algorithm is able to quantify multi-scale high time
resolution autonomic signatures of sleep fragmentation, such as arousals
and stage transitions, throughout an entire night. Results demonstrate
the ability of our methods to track fast dynamic transitions from
sleep to wake and between REM sleep and other sleep stages, providing
resolution details not available in sleep scoring summaries. An automatic
threshold-based procedure is further able to detect brief arousals,
with the instantaneous indices characterizing specific arousal dynamic
signatures.},
check = {2011.09.07},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Citi2011PointProcessHeartBeatDetectionCorrection,
author = {Citi, Luca and Brown, Emery N. and Barbieri, Riccardo},
title = {A Point Process Local Likelihood Algorithm for Robust and Automated
Heart Beat Detection and Correction},
booktitle = {Proceedings of Computing in Cardiology},
year = {2011},
address = {Hangzhou},
month = sep,
abstract = {Robust and automated classification and correction of ECG-derived
heart beats are a necessary prerequisite for an accurate real-time
estimation of measures of heart rate variability and cardiovascular
control. In particular, the low quality of the signal, as well as
the presence of recurring arrhythmic events, may significantly affect
estimation accuracy. We here present a novel point process based
method for a real time R-R interval error detection and correction.
Results of detection analysis over data from the benchmark MIT-BIH
arrhythmia database demonstrate that the proposed algorithm achieves
99.97\% accuracy (98.23\% sensitivity, 99.98\% specificity and 95.69\%
positive predictive value), outperforming state-of-the-art algorithms.
Further results on simulated data demonstrate the efficacy of the
detection and correction method.},
check = {2011.09.07},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Citi2006CharactTFLIFENeurRespContrCybernHand,
author = {Luca Citi and Jacopo Carpaneto and Ken Yoshida and Klaus-Peter Hoffmann
and Klaus-Peter Koch and Paolo Dario and Silvestro Micera},
title = {Characterization of {tfLIFE} Neural Response for the Control of a
Cybernetic Hand},
booktitle = {Proceedings of the 1st {IEEE}/{RAS-EMBS} International Conference
on Biomedical Robotics and Biomechatronics, {B}io{R}ob},
year = {2006},
pages = {477 -482},
address = {Pisa},
month = feb,
abstract = {The development of interfaces that link the human nervous system with
robotic devices or man-made devices has been a main area of research
for several groups in the world. These groups focus on the restoration
of motor and sensory function to those with degenerative diseases,
injury or in amputees. A key component is these systems is a fast,
intuitive, bidirectional interface between the biological and mechatronic
systems that allows the robotic limb to be controlled as if it were
a natural part of the body. Current hand prostheses use electromyographic
(EMG) signals, but are limited to a small number of channels and
to sensing volition. To achieve sensory feedback and a higher number
of control channels, a neuroprosthetic interface are required. In
the present study, thin-film longitudinal intra-fascicular electrodes
(tfLIFE) were implanted in the sciatic nerve of the rabbit. Various
sensory stimuli were applied to the hind limb of the rabbit and the
elicited signals were recorded using the tfLIFEs. These signals were
processed to determine whether the different modes of information
could be decoded. Signals were Kalman filtered, wavelet denoised,
and spike sorted. The classes of spikes found were then used to infer
the stimulus applied to the rabbit. Although the signals acquired
from a single tLIFE gave poor stimulus recognition, the combination
of the signals from multiple sites led to better results. The spike
sorting algorithm is also helped by the use of temporal correlation
between the channels. A direct outcome of the results is the possibility
of increasing the number of channels of control possible with a prosthetic
limb},
check = {2010.10.27},
doi = {10.1109/BIOROB.2006.1639134},
keywords = {EMG;Kalman filter;cybernetic hand;electromyographic signal;hand prostheses;human
nervous system;hybrid bionic system;motor function;neural response;neuroprosthetic
interface;prosthetic limb;robotic device;sciatic nerve;sensory function;sensory
stimuli;spike sorting algorithm;temporal correlation;thin-film longitudinal
intra-fascicular electrode;wavelet denoising;biocybernetics;biomedical
electrodes;electromyography;medical robotics;neurophysiology;prosthetics;},
owner = {lciti},
timestamp = {2006.06.16}
}
@inproceedings{Citi2011PointProcessAnalysisMuscleSpindles,
author = {Citi, Luca and Djilas, Milan and Azevedo-Coste, Christine and Yoshida,
Ken and Brown, Emery N and Barbieri, Riccardo},
title = {Point-Process Analysis of Neural Spiking Activity of Muscle Spindles
Recorded from Thin-Film Longitudinal Intrafascicular Electrodes},
booktitle = {Proceedings of the 33rd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2011},
pages = {2311--2314},
address = {Boston},
month = sep,
abstract = {Recordings from thin-film Longitudinal Intra-Fascicular Electrodes
(tfLIFE) together with a wavelet-based denoising and a correlation-based
spike sorting algorithm, give access to firing patterns of muscle
spindle afferents. In this study we use a point process probability
structure to assess mechanical stimulus-response characteristics
of muscle spindle spike trains. We assume that the stimulus intensity
is primarily a linear combination of the spontaneous firing rate,
the muscle extension, and the stretch velocity. By using the ability
of the point process framework to provide an objective goodness of
fit analysis, we were able to distinguish two classes of spike clusters
with different statistical structure. We found that spike clusters
with higher SNR have a temporal structure that can be fitted by an
inverse Gaussian distribution while lower SNR clusters follow a Poisson-like
distribution. The point process algorithm is further able to provide
the instantaneous intensity function associated with the stimulus-response
model with the best goodness of fit. This important result is a first
step towards a point process decoding algorithm to estimate the muscle
length and possibly provide closed loop Functional Electrical Stimulation
(FES) systems with natural sensory feedback information.},
check = {2011.09.07},
doi = {10.1109/IEMBS.2011.6090581},
owner = {lciti},
timestamp = {2011.09.07},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2011PointProcessAnalysisMuscleSpindles.pdf}
}
@inproceedings{Citi2010PointProcessHRVSleepDeprivation,
author = {Citi, Luca and Klerman, Elizabeth B. and Brown, Emery N. and Barbieri,
Riccardo},
title = {Point process heart rate variability assessment during sleep deprivation},
booktitle = {Proceedings of Computing in Cardiology},
year = {2010},
address = {Belfast},
month = sep,
abstract = {To investigate the potential relationships between Heart rate variability
(HRV) and objective performance-subjective alertness measures during
sleep deprivation, a novel point process algorithm was applied to
ECG data from healthy young subjects in a 52-hour Constant Routine
protocol, which includes sleep deprivation. Our algorithm is able
to estimate the time-varying behavior of the HRV spectral indexes
in an on-line instantaneous fashion. Results demonstrate the ability
of our framework to provide high time-resolution sympatho-vagal dynamics
as measured by spectral low frequency (LF) and high frequency (HF)
power. Correlation analysis on individual subjects reveals a relevant
correspondence between LF/HF and subjective alertness during the
initial hours of sleep deprivation. At longer times awake, high correlation
levels between LF/HF and objective performance indicate an increasing
sympathetic drive as performance measures worsen. These results suggest
that our point-process based HRV assessment could aid in real-time
prediction of performance-alertness.},
check = {TODO},
owner = {lciti},
timestamp = {2010.10.27},
url = {http://web.cinc.org/2010/preprints/315.pdf}
}
@inproceedings{Citi2009ExploitingP300AmplitudeVariations,
author = {Luca Citi and Riccardo Poli and Caterina Cinel},
title = {Exploiting {P300} Amplitude Variations Can Improve Classification
Accuracy in {Donchin's} {BCI} Speller},
booktitle = {Proceedings of the 3rd {IEEE/EMBS} International Conference on Neural
Engineering, {NER}},
year = {2009},
address = {Antalya},
month = apr,
abstract = {The P300 is an endogenous component of EEG event related potentials
which is elicited by rare and significant stimuli. P300s are used
increasingly frequently in Brain Computer Interfaces (BCI) because,
being naturally elicited in response to external stimuli, users do
not need special training. However, P300 waves are hard to detect
and, therefore, multiple stimulus presentations are needed before
an interface can make a reliable decision. While significant improvements
have been made in the detection of P300s, no particular attention
has been paid to the variability in shape and timing of P300 waves
and its exploitation in BCI. In this paper we start filling this
gap, by first documenting and then exploiting a modulation in amplitude
of P300 caused by target-to-target interval (TTI) differences. We
demonstrate this within the context of the Donchin's speller, which
is perhaps the best known example of a BCI system relying on the
detection P300 waves, where target-to-target interval variations
are induced by stimuli randomisation. In particular we show that
by specialising detectors to work with P300s elicited with each TTI,
we can further improve the performance of the best known Donchin's
speller with minimal changes.},
check = {2010.10.27},
doi = {10.1109/NER.2009.5109337},
owner = {lciti},
timestamp = {2009.05.13}
}
@inproceedings{CitiPoliSepulCinel2006AnalogueP300_BasedBCI,
author = {Luca Citi and Riccardo Poli and Caterina Cinel},
title = {Analogue {P300-based} {BCI} pointing device},
booktitle = {Proceedings of the 3rd International {BCI} Workshop and Training
Course},
year = {2006},
pages = {92--93},
address = {Graz},
month = sep,
abstract = {We propose a P300-based BCI mouse. The system is analogue: the pointer
is controlled by directly combining the amplitudes of the outputs
produced by a filter in the presence of different stimuli. The system
is optimised by a genetic algorithm.},
check = {2010.10.27},
issue = {1},
owner = {lciti},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2006AnalogueP300basedBCI.pdf}
}
@inproceedings{CitiPoliSepul2004EvolApprFeatSelectAndClassP300BCI,
author = {Luca Citi and Riccardo Poli and Francisco Sepulveda},
title = {An evolutionary approach to feature selection and classification
in {P300}-based {BCI}},
booktitle = {Proceedings of the 2nd International {BCI} workshop and Training
Course},
year = {2004},
pages = {41--42},
address = {Graz},
month = sep,
abstract = {We explore the use of evolutionary algorithms in the selection of
features and the classification of P300 signals in BCI. As a result
we have found new ways to process and combine EEG signals to improve
detection.},
aka = {CitiPoliSepul_2004_EvolApprFeatSelectAndClassP300BCI},
check = {2010.10.27},
owner = {lciti},
url = {http://users.neurostat.mit.edu/lciti/publications_files/Citi2004EvolApprFeatSelectAndClassP300BCI.pdf}
}
@inproceedings{Citi2012InstantaneousLyapunov,
author = {Citi, L. and Valenza, G. and Barbieri, R.},
title = {Instantaneous estimation of high-order nonlinear heartbeat dynamics
by {L}yapunov exponents},
booktitle = {Proceedings of the 34th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2012},
pages = {13--16},
address = {San Diego},
__markedentry = {[lciti:]},
abstract = {This paper introduces a novel methodology able to provide time varying
estimates of the Lyapunov Spectrum within a point process framework.
The algorithm is applied to ECG-derived data to characterize heartbeat
nonlinear dynamics by using a cubic autoregressive point process
model. Estimation of the model parameters is ensured by the Laguerre
expansion of the Wiener-Volterra kernels along with a maximum local
log-likelihood procedure. In addition to the instantaneous Lyapunov
exponents, as well as indices related to higher order dynamic polyspectra,
our method is also able to provide all the instantaneous time domain
and frequency domain measures of instantaneous heart rate (HR) and
heart rate variability (HRV) previously considered. Experimental
results show that our method is able to track complex cardiovascular
control dynamics during fast transitional gravitational changes.},
check = {2012.12.13},
doi = {10.1109/EMBC.2012.6345859},
owner = {lciti},
timestamp = {2012.12.13}
}
@inproceedings{Citi2012MonitoringAnesthesiaLyapunov,
author = {Citi, L. and Valenza, G. and Purdon, P.L. and Brown, E.N. and Barbieri,
R.},
title = {Monitoring heartbeat nonlinear dynamics during general anesthesia
by using the instantaneous dominant {L}yapunov exponent},
booktitle = {Proceedings of the 34th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2012},
pages = {3124--3127},
address = {San Diego},
__markedentry = {[lciti:]},
abstract = {We present a novel methodology for instantaneous estimation of quantitative
correlates of depth of Anesthesia from noninvasive electrocardiographic
recordings. The analysis is based on a point process model of heartbeat
dynamics that allows for continuous tracking of linear and nonlinear
HRV indices, including a novel instantaneous assessment of the Lyapunov
Spectrum by using a cubic autoregressive formulation. The effective
estimation of the model parameters is ensured by the Laguerre expansion
of the Wiener-Volterra kernels along with the maximum local log-likelihood
procedure. We apply the proposed assessment to experimental recordings
from healthy subjects during propofol anesthesia. The new assessment
reveals novel time-varying complex heartbeat dynamics that underlie
the quasi-periodic heartbeat fluctuations elicited by the sympatho-vagal
balance. Results suggest that such quantification provides important
information which is independent from the standard autonomic assessment
and significantly correlated with loss of consciousness. Further
investigation will focus on evolving our mathematical approach towards
a promising monitoring tool for an accurate, noninvasive assessment
of general anesthesia.},
check = {2012.12.13},
doi = {10.1109/EMBC.2012.6346626},
owner = {lciti},
timestamp = {2012.12.13}
}
@inproceedings{DiGiovanna2008InferringStabilityLIFE,
author = {Jack DiGiovanna and Luca Citi and Ken Yoshida and Jacopo Carpaneto
and Jose C Principe and Justin C Sanchez and Silvestro Micera},
title = {Inferring the stability of LIFE through Brain Machine Interfaces.},
booktitle = {Proceedings of the 30th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2008},
volume = {2008},
pages = {2008--2011},
address = {Vancouver},
month = aug,
abstract = {We examine neural signals from Longitudinally implanted Intra-Fascicular
Electrodes (LIFE) in a chronic, rabbit model. Translation-invariant
wavelet de-noising methods are used to improve S\%R. Then traditional
template-based spike sorting is applied to discriminate single units.
We investigate the effect of discriminating between identified units
on Brain Machine Interface (BMI) decoding performance. We infer the
stability of LIFE based on decoding performance with and without
current BMI methods to counter-act electrode neural signal degradation.},
check = {2010.10.27},
doi = {10.1109/IEMBS.2008.4649584},
institution = {Dept. of Biomedical Engineering, University of Florida, Gainesville,
FL 32611, USA. jfd134@ufl.edu},
keywords = {Action Potentials; Algorithms; Animals; Electrodes, Implanted; Electrophysiology;
Female; Models, Neurological; Muscle, Skeletal; Rabbits; Signal Processing,
Computer-Assisted; User-Computer Interface},
owner = {lciti},
pmid = {19163087},
timestamp = {2009.05.13}
}
@inproceedings{Ellis2011PointProcessGaitVariability,
author = {Ellis, Robert J and Citi, Luca and Barbieri, Riccardo},
title = {A point process approach for analyzing gait variability dynamics},
booktitle = {Proceedings of the 33rd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2011},
address = {Boston},
month = sep,
abstract = {We present a novel statistical paradigm for modeling and analysis
of gait variability which captures the natural point process structure
of gait intervals and allows for definition of new measures instantaneous
mean and standard deviation. We validate our model using two existing
data sets from physionet.org. Results show an excellent model fit
and yield insights into the underlying statistical structure behind
human gait. Statistical analyses further corroborate previous findings
of increased variability in gait at different speeds, both self-paced
and metronome-paced, and reveal a significant increase in gait variability
in Parkinson's subjects, as compared to young and elderly healthy
subjects. These results indicate the validity of a point process
approach to the analysis of gait, and the potential utility of incorporating
instantaneous measures of gait into diagnostic or patient monitoring
applications.},
check = {2011.09.07},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Menon2006ProspectsOfBCIForSpace,
author = {Carlo Menon and de Negueruela, Cristina and del R. Mill\'an, Jos\'e
and Oliver Tonet and Federico Carpi and Michael Broschart and Pierre
Ferrez and Anna Buttfield and Paolo Dario and Luca Citi and Cecilia
Laschi and Mario Tombini and Francisco Sepulveda and Riccardo Poli
and Ramaswamy Palaniappan and Franca Tecchio and Rossini, Paolo Maria
and De Rossi, Danilo},
title = {Prospects of {B}rain-{M}achine {I}nterfaces for space system control},
booktitle = {Proceedings of the 57th International Astronautical Congress},
year = {2006},
address = {Valencia},
month = oct,
abstract = {The dream of controlling and guiding computer-based systems using
human brain signals has slowly but steadily become a reality. The
available technology allows real-time implementation of systems that
measure neuronal activity, convert their signals, and translate their
output for the purpose of controlling mechanical and electronic systems.
This paper describes the state of the art of non-invasive brain-machine
interfaces (BMIs) and critically investigates both the current technological
limits and the future potential that BMIs have for space applications.
We present an assessment of the advantages that BMIs can provide
and justify the preferred candidate concepts for space applications
together with a vision of future directions for their implementation.},
check = {2011.08.17},
owner = {lciti}
}
@inproceedings{Micera2009ControlRobotHandByNeuralSignalsPNS,
author = {S. Micera and J. Rigosa and J. Carpaneto and L. Citi and S. Raspopovic
and E. Guglielmelli and A. Benvenuto and L. Rossini and G. Di Pino
and G. Cavallo and M. C. Carrozza and C. Cipriani and K. P. Hoffmann
and P. Dario and P. M. Rossini},
title = {On the control of a robot hand by extracting neural signals from
the {PNS}: preliminary results from a human implantation.},
booktitle = {Proceedings of the 31st {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2009},
volume = {2009},
pages = {4586--4589},
address = {Minneapolis},
month = sep,
abstract = {The development of hybrid neuroprosthetic systems (HBSs) linking the
human nervous system with artificial devices is an important area
of research that is currently addressed by several groups to restore
sensorimotor function in people affected by different disabilities.
It is particularly important to establish a fast, intuitive, bidirectional
flow of information between the nervous system of the user and the
smart robotic device. Among the possible solutions to achieve this
goal, interfaces with the peripheral nervous system and in particular
intraneural electrodes can represent an interesting choice. In the
present study, thin-film longitudinal intra-fascicular electrodes
were implanted in the median and ulnar nerves of an amputee. The
possibility of restoring the bidirectional link between the subject
and the external world was investigated during a 4 week trial. The
result showed that both the extraction of motor information and the
restoration of sensory function are possible.},
check = {2011.01.12},
doi = {10.1109/IEMBS.2009.5332764},
institution = {ARTS Lab, Scuola Superiore Sant'Anna, Pisa, Italy. micera@sssup.it},
keywords = {Algorithms; Amputees; Artificial Limbs; Electrodiagnosis, methods;
Evoked Potentials, Motor, physiology; Humans; Man-Machine Systems;
Median Nerve, physiology; Peripheral Nervous System, physiology;
Robotics, methods; Signal Processing, Computer-Assisted; Ulnar Nerve,
physiology},
owner = {lciti},
pmid = {19963845},
timestamp = {2010.10.27}
}
@inproceedings{Micera2006ExperDevelopNewGenerElectr,
author = {Micera, S. and Sergi, P.N. and Carpaneto, J. and Citi, L. and Bossi,
S. and Koch, K.-P. and Hoffmann, K.-P. and Menciassi, A. and Yoshida,
K. and Dario, P.},
title = {Experiments on the development and use of a new generation of intra-neural
electrodes to control robotic devices},
booktitle = {Proceedings of the 28th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2006},
pages = {2940 -2943},
address = {New York City},
month = sep,
abstract = {The development of interfaces linking the human nervous system with
artificial devices is an important area of research and several groups
are now addressing it. Interfaces represent the key enabling technology
for the development of devices usable for the restoration of motor
and sensory function in subjects affected by neurological disorders,
injuries or amputations. For example, current hand prostheses use
electromyographic (EMG) signals to extract volitional commands but
this limits the possibility of controlling several degrees of freedom
and of delivering sensory feedback. To achieve these goals, implantable
neural interfaces are required. Among the candidate interfaces with
the peripheral nervous system intra-neural electrodes seem to be
an interesting solution due to their bandwidth and ability to access
volition and deliver sensory feedback. However, several drawbacks
have to be addressed in order to increase their usability. In this
paper, experiments to address many of these issues are presented
as part of the development of a new generation of intra-neural electrodes.
The results showed seem to confirm that these new interfaces seem
to have interesting properties and that they can represent a significant
improvement of the state of the art. Extensive experiments will be
carried out in the future to validate these results},
check = {2010.10.27},
doi = {10.1109/IEMBS.2006.260346},
issn = {1557-170X},
keywords = {PNS;artificial device;current hand prostheses;electromyographic signal;human
nervous system;implantable neural interface;intraneural electrodes;neuro-robotics;neurological
disorder;peripheral nervous system;robotic device control;sensory
feedback;biomedical electrodes;medical robotics;neurophysiology;prosthetics;},
owner = {lciti},
pmid = {17945747}
}
@inproceedings{Orini2012BivariatePointProcessPTT,
author = {Orini, M. and Citi, L. and Barbieri, R.},
title = {Bivariate point process modeling and joint non-stationary analysis
of pulse transit time and heart period},
booktitle = {Proceedings of the 34th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2012},
pages = {2831--2834},
address = {San Diego},
__markedentry = {[lciti:]},
abstract = {Pulse transit time (PTT) is strictly related to pulse wave velocity
and may be used for non-invasive monitoring of arterial stiffness
and pressure, whose assessment is fundamental to detect cardiovascular
dysfunctions. We propose a new model to characterize instantaneous
PTT dynamics, and the interactions between PTT and R-R interval (RRI).
In this model, PTT is described as a point process whose probability
function depends on previous PTT and RRI values. From the model coefficients,
instantaneous powers, coherence and directed coherence of each spectral
component are estimated. We used this framework to study the changes
that tilt table test provoked in PTT and RRI dynamics in 17 healthy
subjects. Time-varying spectral and coherence analysis revealed that,
although PTT and RRI were locally correlated, direct contribution
of RRI on PTT was low during the entire test in high frequency band,
and just after postural changes in low frequency band. We conclude
that PTT may add valuable information for a more accurate characterization
of cardiovascular regulation.},
check = {2012.12.13},
doi = {10.1109/EMBC.2012.6346553},
owner = {lciti},
timestamp = {2012.12.13}
}
@inproceedings{Orini2012TetravariatePointProcess,
author = {Orini, M. and Valenza, G. and Citi, L. and Barbieri, R.},
title = {Tetravariate Point-Process Model for the Continuous Characterization
of Cardiovascular-Respiratory Dynamics during Passive Postural Changes},
booktitle = {Computing in Cardiology},
year = {2012},
address = {Krakow},
month = sep,
__markedentry = {[lciti:]},
abstract = {In this study, we present a new methodology for time-varying characterization
of cardiovascular (CV) control, which includes RR interval (RRI),
systolic arterial pressure (SAP), respiration (RSP) and pulse transit
time (PTT). Within a multivariate model, CV dynamics are represented
as stochastic point processes whose means has a tetravariate autoregressive
structure. Such framework provides the simultaneous time-frequency
assessment of: (i) both arms of the SAP-RRI loop, along baroreflex
and mechanical feedforward pathways; (ii) Respiratory sinus arrhythmia
(RSA), through the direct evaluation of the interactions between
RSP and the RRI; (iii) the coupling between cardiorespiratory activity
and vascular tone through quantification of the interactions between
PTT and the other CV variables. We validated the model by characterizing
CV control in 16 healthy subjects during a tilt table test, and we
were able to confirm a satisfactory model's goodness-of-fit. We further
estimated transfer function gains, instantaneous powers and directed
coherences, and observed that RSP strongly drove respiratory-related
oscillations in all the other CV variables, and that PTT depended
on RRI dynamics rather than blood pressure variations. During head-up
tilt, baroreflex sensitivity and RSA decreased, while the gain from
RRI to SAP increased, thus confirming previous physiological characterizations.},
check = {2012.12.13},
owner = {lciti},
timestamp = {2012.12.13},
url = {http://cinc.mit.edu/archives/2012/pdf/0273.pdf}
}
@inproceedings{Pani2011RealTimeProcessingTfLIFE,
author = {Pani, Danilo and Usai, Francesco and Citi, Luca and Raffo, Luigi},
title = {Real-time processing of {tfLIFE} neural signals on embedded {DSP}
platforms: A case study},
booktitle = {Proceedings of the 5th {IEEE/EMBS} International Conference on Neural
Engineering, {NER}},
year = {2011},
pages = {44--47},
address = {Cancun},
month = apr,
abstract = {Spike sorting is a typical neural processing technique aimed at identifying
the firing activity of individual neurons. It plays a different role
in the processing of the signals coming either from a single electrode
or an electrode array. In presence of highly noisy recordings, a
preliminary denoising stage is required in order to improve the SNR.
Despite the significant number of studies in the field, only a few
of them deal with peripheral nervous system (PNS) recordings and
often the possibility of a real-time implementation is only hinted
without any real implementation study. In this paper, a real-time
PNS signal processing and classification technique is presented end
evaluated on real elec-troneurographic signals taken from the sciatic
nerve of rats. A state-of-the-art algorithm, composed of a wavelet
denoising preprocessing stage followed by a correlation-based spike
sorting and a support vector machine, has been adapted to work on-line
in order to improve the processing efficiency while preserving at
the most its effectiveness. The algorithm provides some level of
adaptiveness with respect to an off-line implementation. On average,
the correct classification reach 92.24% with isolated errors that
can be easily filtered out. Cycle-accurate profiling results on an
off-the-shelf Digital Signal Processor demonstrate the real-time
performance.},
check = {2011.09.07},
doi = {10.1109/NER.2011.5910485},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{Poli2011GPApproachDetectArtifact,
author = {Poli, Riccardo and Cinel, Caterina and Citi, Luca and Salvaris, Mathew},
title = {A genetic programming approach to detecting artifact-generating eye
movements from EEG in the absence of electro-oculogram},
booktitle = {Proceedings of the 5th {IEEE/EMBS} International Conference on Neural
Engineering, {NER}},
year = {2011},
pages = {416--421},
address = {Cancun},
month = apr,
abstract = {In this paper we use genetic programming an evolutionary program-induction
technology to evolve algorithms that accurately approximate the behaviour
of two standard detectors of ocular movement based on Electro-oculogram
({EOG}). The prediction is based entirely on {EEG} signals, i.e.,
without using {EOG}, making it possible to detect eye movements even
in data recorded without {EOG} or eye tracking. Experimental results
with this approach are very encouraging.},
check = {2011.09.07},
doi = {10.1109/NER.2011.5910575},
owner = {lciti},
timestamp = {2011.09.07}
}
@inproceedings{PoliCinelCitiSepulv2007EvolutionaryBCI,
author = {Riccardo Poli and Caterina Cinel and Luca Citi and Francisco Sepulveda},
title = {Evolutionary Brain Computer Interfaces.},
booktitle = {Proceedings of the EvoWorkshops},
year = {2007},
pages = {301--310},
address = {Valencia},
month = apr,
abstract = {We propose a BCI mouse and speller based on the manipulation of P300
waves in EEG signals. The 2---D motion of the pointer on the screen
is controlled by directly combining the amplitudes of the output
produced by a filter in the presence of different stimuli. This filter
and the features to be combined within it are optimised by a GA.},
check = {2010.10.27},
owner = {lciti}
}
@inproceedings{Poli2010EigenbrainsFreeVibrationalModes,
author = {Poli, Riccardo and Citi, Luca and Salvaris, Mathew and Cinel, Caterina
and Sepulveda, Francisco},
title = {Eigenbrains: the Free Vibrational Modes of the Brain as a New Representation
for {EEG}},
booktitle = {Proceedings of the 32nd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2010},
volume = {2010},
pages = {6011--6014},
address = {Buenos Aires},
month = sep,
abstract = {We present a new transform for EEG signals whose basis functions are
well suited to represent the large-scale dynamics associated with
event related potentials. The method involves instantiating an approximate
model of the electrical properties of the brain as a conductor medium
and then studying the free vibrational modes of the model. These
form a set of basis functions, which we call eigenbrains, that can
be used to meaningfully re-represent the brain's electrical activity.
Eigenbrains are compared to principal component analysis and independent
component analysis to highlight differences and similarities.},
check = {2011.09.07},
doi = {10.1109/IEMBS.2010.5627593},
owner = {lciti},
pmid = {21097112},
timestamp = {2011.09.07}
}
@inproceedings{Poli2009MemoryWithMemoryTreeBasedGP,
author = {Poli, Riccardo and Mcphee, Nicholas F. and Citi, Luca and Crane,
Ellery},
title = {Memory with Memory in Tree-Based Genetic Programming},
booktitle = {Proceedings of the 12th European Conference on Genetic Programming,
EuroGP '09},
year = {2009},
pages = {25--36},
address = {T\"{u}bingen},
month = apr,
abstract = {In recent work on linear register-based genetic programming (GP) we
introduced the notion of Memory-with-Memory (MwM), where the results
of operations are stored in registers using a form of soft assignment
which blends a result into the current content of a register rather
than entirely replace it. The MwM system yielded very promising results
on a set of symbolic regression problems. In this paper, we propose
a way of introducing MwM style behaviour in tree-based GP systems.
The technique requires only very minor modifications to existing
code, and, therefore, is easy to apply. Experiments on a variety
of synthetic and real-world problems show that MwM is very beneficial
in tree-based GP, too.},
check = {2010.10.28},
doi = {10.1007/978-3-642-01181-8_3},
isbn = {978-3-642-01180-1},
owner = {lciti},
timestamp = {2010.10.28}
}
@inproceedings{Salvaris2010ExploringMultipleProtocolsBCIMouse,
author = {Salvaris, Mathew and Cinel, Caterina and Poli, Riccardo and Citi,
Luca and Sepulveda, Francisco},
title = {Exploring Multiple Protocols for a Brain-Computer Interface Mouse},
booktitle = {Proceedings of the 32nd {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2010},
pages = {4189--4192},
address = {Buenos Aires},
month = sep,
abstract = {In recent years, various visual protocols have been explored for {P300}-based
{BCI}. In stimulus-driven {BCI} paradigms such as {P300} {BCIs} it
is vital to optimise the stimulation protocol as much as possible
in order to achieve the best performance. Due to the inherent variability
between subjects and the complex nature of the brain it is unlikely
that an optimal protocol will be identified through a single iteration
of random exploration. That is why in this paper we explore 8 different
visual protocol configurations based on recent literature, in the
hope of identifying key features that can later be used to create
further improved protocols. Results indicate that luminosity changes,
the standard method of stimulation used in visual {P300} {BCI} protocols,
do provide the best performance of the variations presented here.},
check = {2011.09.07},
doi = {{10.1109/IEMBS.2010.5627388}},
owner = {lciti},
pmid = {21096890},
timestamp = {2011.09.07}
}
@inproceedings{Valenza2012LaguerrePointProcess,
author = {Valenza, G. and Citi, L. and Scilingo, E.P. and Barbieri, R.},
title = {Using {L}aguerre expansion within point-process models of heartbeat
dynamics: A comparative study},
booktitle = {Proceedings of the 34th {IEEE} Engineering in Medicine and Biology
Society Conference, {EMBC}},
year = {2012},
pages = {29--32},
address = {San Diego},
__markedentry = {[lciti:]},
abstract = {Point-process models have been recognized as a distinguished tool
for the instantaneous assessment of heartbeat dynamics. Although
not thoroughly linked to the physiology, nonlinear models also yield
a more accurate quantification of cardiovascular control dynamics.
Here, we propose a Laguerre expansion of the linear and nonlinear
Wiener-Volterra kernels in order to account for the nonlinear and
non-gaussian information contained in the ECG-derived heartbeat series
while using a reduced number of parameters. Within an Inverse-Gaussian
probability model, up to quadratic nonlinearities were considered
to continuously estimate the dynamic spectrum and bispectrum. Results
performed on 10 subjects undergoing a stand-up protocol show that
this novel methodology improves on the algorithmic performances and,
at the same time, more accurately characterizes sympatho-vagal changes
to posture.},
check = {2012.12.13},
doi = {10.1109/EMBC.2012.6345863},
owner = {lciti},
timestamp = {2012.12.13}
}
@inproceedings{Yoshida2007RecordingExperienceLIFEs,
author = {Yoshida, K. and Kurstjens, M. and Citi, L. and Koch, K.P. and Micera,
S.},
title = {Recording experience with the thin-film Longitudinal Intra-Fascicular
Electrode, a multichannel peripheral nerve interface},
booktitle = {Proceedings of the 10th IEEE International Conference on Rehabilitation
Robotics ICORR},
year = {2007},
pages = {862--867},
address = {Noordwijk},
month = jun,
abstract = {This paper presents our experience evaluating a multi-channel peripheral
nerve interface, the thin-film longitudinal intra-fascicular electrode
(tfLIFE). One application for the tfLIFE is their potential use as
a means to detect independent channels of volitional commands from
the amputee. The neural interface would be required to be sufficiently
selective to detect the activity of single motor nerve fibres within
the nerve stump. Experiments were conducted in the acute rabbit model
evaluate the recording characteristics of the tfLIFE array. Multiunit
activity was recorded in response to mechanical stimulation of peripheral
mechanoreceptors. In some channels in all experiments, large single
unit spikes were clearly visible. These data were then processed
to determine whether an artificial discriminator could be trained
to detect and track activity from the multi unit recordings. We also
tested whether inclusion of multi channel information could be used
to improve the performance of the discriminator. Our preliminary
results indicate the inclusion of multiple channels significantly
improves the performance.},
check = {2010.10.27},
doi = {10.1109/ICORR.2007.4428525},
keywords = {biomedical electrodes, discriminators, mechanoception, neuromuscular
stimulation, prosthetics, thin film devices, acute rabbit model,
amputee, artificial discriminator, mechanical stimulation, multichannel
peripheral nerve interface, peripheral mechanoreceptors, single motor
nerve fibres, thin-film longitudinal intra-fascicular electrode,
volitional commands},
owner = {lciti},
timestamp = {2008.09.07}
}
@phdthesis{LCitiPhd,
author = {Luca Citi},
title = {Development of a neural interface for the control of a robotic hand},
school = {IMT Lucca and Scuola Superiore Sant'Anna Pisa},
year = {2009},
month = apr,
abstract = {The restoration of sensorimotor functions for the control ofartificial
hands is a fundamental point in order to improve the quality of life
of amputees. Current hand prostheses use electromyographic (EMG)
signals, but are limited to a small number of channels and rely on
visual feedback. As the interface is the bottleneck for a wide class
of hybrid bionic systems, we have developed a general framework to
match task requirements with interface performance. We have carefully
and thoroughly examined the case of the amputee user and its requirements:
throughput and latency, but also user-friendliness, invasiveness,
bi-directionality, and possibility of natural control of the prosthesis.
From this analysis, we have concluded that, albeit suboptimal from
a mere throughput and latency point of view, peripheral invasive
interface can represent a promising medium-term solution. We have
compared the different types of interfaces with the peripheral nervous
system, finding in longitudinal intra-fascicular interfaces (LIFEs)
a tradeoff between invasiveness and selectivity. In order to assess
the possibility of extracting complex information from LIFEs, we
have run preliminary experiments with small animal models recording
induced afferent information. Using the sophisticated signal processing
techniques developed (wavelet denoising and spike sorting) and a
robust classifier, we were able to discriminate four (or five) different
classes of stimuli with performance in a range between 90\% and 99\%.
These results confirmed and outperformed prior work carried out with
different approaches. There are plans to validate the approach with
a human amputee. Hence, several steps have been taken in order to
make possible the recording of neural signals from a human subject
and allow online processing and control of the ``Cyberhand'' smart
robotic hand prosthesis.},
check = {2010.10.27},
owner = {lciti},
timestamp = {2010.10.28},
url = {http://users.neurostat.mit.edu/lciti/publications_files/LCitiPhD.pdf}
}
@mastersthesis{LCitiMSThesis,
author = {Luca Citi},
title = {Un'interfaccia cervello-computer mediante metodi evoluzionistici
di trattamento di segnali {EEG}},
school = {Universit\`a degli Studi di Firenze},
year = {2004},
month = jul,
check = {2010.10.27},
owner = {lciti},
timestamp = {2010.10.28},
url = {http://users.neurostat.mit.edu/lciti/publications_files/LCitiMSThesis.pdf}
}
