Leonardo Duque-Muñoz

Dr. Leonardo Duque-Muñoz

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 March 2018 in Nature
Verified
Journal Article
Closed access
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EBElena Boto
Elena Boto
NHNiall Holmes
Niall Holmes
JLJames Leggett
James Leggett
GRGillian Roberts
Gillian Roberts
VSVishal Shah
Vishal Shah
MBMatthew J. Brookes
Matthew J. Brookes

1 November 2018 in NeuroImage
Verified
Journal Article
Open access
TTTim M. Tierney
Tim M. Tierney
NHNiall Holmes
Niall Holmes
SMSofie S. Meyer
Sofie S. Meyer
EBElena Boto
Elena Boto
GRGillian Roberts
Gillian Roberts
GBGareth R. Barnes
Gareth R. Barnes
Recent work has demonstrated that Optically Pumped Magnetometers (OPMs) can be utilised to create a wearable Magnetoencephalography (MEG) system that is motion robust. In this study, we use this system to map eloquent cortex using a clinically validated language lateralisation paradigm (covert verb generation: 120 trials, ∼10 min total duration) in healthy adults (n = 3). We show that it is possible to lateralise and localise language function on a case by case basis using this system. Specifically, we show that at a sensor and source level we can reliably detect a lateralising beta band (15-30 Hz) desynchronization in all subjects. This is the first study of human cognition using OPMs and not only highlights this technology's utility as tool for (developmental) cognitive neuroscience but also its potential to contribute to surgical planning via mapping of eloquent cortex, especially in young children.


11 July 2019 in Human Brain Mapping
Verified
Journal Article
Open access
PDF file
LDLeonardo Duque-Muñoz
Leonardo Duque-Muñoz
TTTim M. Tierney
Tim M. Tierney
SMSofie S. Meyer
Sofie S. Meyer
EBElena Boto
Elena Boto
NHNiall Holmes
Niall Holmes
GBGareth Barnes
Gareth Barnes
Optically pumped magnetometers (OPMs) have reached sensitivity levels that make them viable portable alternatives to traditional superconducting technology for magnetoencephalography (MEG). OPMs do not require cryogenic cooling and can therefore be placed directly on the scalp surface. Unlike cryogenic systems, based on a well‐characterised fixed arrays essentially linear in applied flux, OPM devices, based on different physical principles, present new modelling challenges. Here, we outline an empirical Bayesian framework that can be used to compare between and optimise sensor arrays. We perturb the sensor geometry (via simulation) and with analytic model comparison methods estimate the true sensor geometry. The width of these perturbation curves allows us to compare different MEG systems. We test this technique using simulated and real data from SQUID and OPM recordings using head‐casts and scanner‐casts. Finally, we show that given knowledge of underlying brain anatomy, it is possible to estimate the true sensor geometry from the OPM data themselves using a model comparison framework. This implies that the requirement for accurate knowledge of the sensor positions and orientations a priori may be relaxed. As this procedure uses the cortical manifold as spatial support there is no co‐registration procedure or reliance on scalp landmarks.

28 August 2014 in BioMedical Engineering OnLine
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Journal Article
Open access
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LDLeonardo Duque-Muñoz
Leonardo Duque-Muñoz
JEJairo José Espinosa
Jairo José Espinosa
GCGerman Castellanos-Dominguez
German Castellanos-Dominguez
The extraction of physiological rhythms from electroencephalography (EEG) data and their automated analyses are extensively studied in clinical monitoring, to find traces of interictal/ictal states of epilepsy. Because brain wave rhythms in normal and interictal/ictal events, differently influence neuronal activity, our proposed methodology measures the contribution of each rhythm. These contributions are measured in terms of their stochastic variability and are extracted from a Short Time Fourier Transform to highlight the non–stationary behavior of the EEG data. Then, we performed a variability–based relevance analysis by handling the multivariate short–time rhythm representation within a subspace framework. This maximizes the usability of the input information and preserves only the data that contribute to the brain activity classification. For neural activity monitoring, we also developed a new relevance rhythm diagram that qualitatively evaluates the rhythm variability throughout long time periods in order to distinguish events with different neuronal activities. Evaluations were carried out over two EEG datasets, one of which was recorded in a noise–filled environment. The method was evaluated for three different classification problems, each of which addressed a different interpretation of a medical problem. We perform a blinded study of 40 patients using the support–vector machine classifier cross–validation scheme. The obtained results show that the developed relevance analysis was capable of accurately differentiating normal, ictal and interictal activities. The proposed approach provides the reliable identification of traces of interictal/ictal states of epilepsy. The introduced relevance rhythm diagrams of physiological rhythms provides effective means of monitoring epileptic seizures; additionally, these diagrams are easily implemented and provide simple clinical interpretation. The developed variability–based relevance analysis can be translated to other monitoring applications involving time–variant biomedical data.

23 December 2021 in IEEE Latin America Transactions
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Journal Article
Closed access
DADaniel Fernando Terraza Arciniegas
Daniel Fernando Terraza Arciniegas
MAMauricio Amaya
Mauricio Amaya
ACAlejandro Piedrahita Carvajal
Alejandro Piedrahita Carvajal
PRPaula Rodriguez
Paula Rodriguez
LDLeonardo Duque-Muñoz
Leonardo Duque-Muñoz
JVJuan David Martinez Vargas
Juan David Martinez Vargas
The students' attention level to the explanation of a given lecture is a factor that might determine the capability of retention and subsequent application of a learned concept. For this reason, students that pay attention are generally more participatory in the learning/teaching process than those who don't, and consequently, they succeed in reaching the competencies proposed in the courses. Hence, it is important to design strategies and tools that help teachers to monitor in a non-invasive way the attention level of the students, allowing them to take actions to modify the dynamics of the lectures when needed. In this work, we introduce a fully automated system to monitor the students' attention based on computer vision algorithms. To this end, we feed a recurrent neural network with one-second sequences generated by facial landmarks. This spatiotemporal analysis of video recordings allows for identifying when a student is attending a given explanation in online educational environments. The system is tested in a database with more than 3000 sequences of students who pay or no attention to online video lectures. Obtained results show that the proposed system is suitable to monitor the students' attention to a particular explanation.