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1. Smartphone-Based Pupillometry Using Machine Learning for the Diagnosis of Sports-Related Concussion

Author

Anthony J. Maxin, Bridget M. Whelan, Michael R. Levitt, Lynn B. McGrath, and Kimberly G. Harmon

Subjects
smartphone pupillometry, sports-related concussion, diagnostics, biomarkers, pupillary light reflex, digital health, Medicine (General), R5-920
Abstract

Background: Quantitative pupillometry has been proposed as an objective means to diagnose acute sports-related concussion (SRC). Objective: To assess the diagnostic accuracy of a smartphone-based quantitative pupillometer in the acute diagnosis of SRC. Methods: Division I college football players had baseline pupillometry including pupillary light reflex (PLR) parameters of maximum resting diameter, minimum diameter after light stimulus, percent change in pupil diameter, latency of pupil constriction onset, mean constriction velocity, maximum constriction velocity, and mean dilation velocity using a smartphone-based app. When an SRC occurred, athletes had the smartphone pupillometry repeated as part of their concussion testing. All combinations of the seven PLR parameters were tested in machine learning binary classification models to determine the optimal combination for differentiating between non-concussed and concussed athletes. Results: 93 football athletes underwent baseline pupillometry testing. Among these athletes, 11 suffered future SRC and had pupillometry recordings repeated at the time of diagnosis. In the machine learning pupillometry analysis that used the synthetic minority oversampling technique to account for the significant class imbalance in our dataset, the best-performing model was a random forest algorithm with the combination of latency, maximum diameter, minimum diameter, mean constriction velocity, and maximum constriction velocity PLR parameters as feature inputs. This model produced 91% overall accuracy, 98% sensitivity, 84.2% specificity, area under the curve (AUC) of 0.91, and an F1 score of 91.6% in differentiating between baseline and SRC recordings. In the machine learning analysis prior to oversampling of our imbalanced dataset, the best-performing model was k-nearest neighbors using latency, maximum diameter, maximum constriction velocity, and mean dilation velocity to produce 82% accuracy, 40% sensitivity, 87% specificity, AUC of 0.64, and F1 score of 24%. Conclusions: Smartphone pupillometry in combination with machine learning may provide fast and objective SRC diagnosis in football athletes.

Published
2024
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2. Post-processing of a distributed source method for the localization of somatosensory cortex in a cohort of epilepsy patients

Author

Kevin Tyner, Matthew McCumber, Srijita Das, Carmen Urban, Anthony J. Maxin, Tiffany Chu, Mustaffa Alfatlawi, and Stephen V. Gliske

Subjects
Magnetoencephalography, Somatosensory evoked field, Singular value decomposition, Source localization, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Localizing eloquent cortices is crucial for many neurosurgical applications, such as epilepsy and tumor resections. Clinicians may use non-invasive methods such as magnetoencephalography (MEG) to localize these cortical regions using equivalent current dipoles (ECDs). While dipoles are clinically validated, they provide the estimated strength, location, and orientation of only one or a few sources that best describe the recorded neuromagnetic data, requiring clinicians to make subjective decisions on the spatial extent of the underlying cortical area. More accurate delineation of eloquent cortical areas using distributed source localization methods would provide additional pre-surgical information on these regions’ location and spatial distribution, which could lead to reduced post-surgical complications associated with damage to or removal of eloquent cortices. Our objective in this paper was to present a method to post-process the distributed source localization results to yield a directly interpretable, distributed region of activation. As a test case, we selected somatosensory stimulation in a retrospective cohort of focal and multi-focal epilepsy patients. Our algorithm performs source localization using a distributed method (sLORETA), followed by post-processing and blind source separation to identify the area and boundary of the cortical tissue that primarily activates in response to somatosensory stimulation. We calculated the statistical significance of localization by comparing the identified region to an anatomical atlas and random chance. While examining patients who received left (upper left, UL) and right (upper right, UR) sided median nerve stimulation, the cortical areas identified by the algorithm were in anatomically appropriate areas with a median overlap of 97.6% and 94.7%, respectively. We observe that our algorithm localized somatosensory responses better than random chance in 57/58 (98%) patients who performed the UL task (p

Published
2024
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3. Mini and micro-resonators for the generation of high spectral purity microwave signals

Author

L. Morvan, A. Bouchier, Y. Chembo, D. Dolfi, Y. Dumeige, P. Féron, M. Ferrari, L. Larger, E. Le Cren, O. Llopis, J. Maxin, P. Merrer, G. Nunzi Conti, G. Pillet, K. Saleh, P. Salzenstein, F. Van Dijk, G. Cibiel, Thales Research and Technology [Palaiseau], THALES, Service Techniques et Équipements Appliqués à la Microélectronique ( LAAS-TEAM ), Laboratoire d'analyse et d'architecture des systèmes [Toulouse] ( LAAS ), Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut National Polytechnique [Toulouse] ( INP ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies ( FEMTO-ST ), Université de Technologie de Belfort-Montbeliard ( UTBM ) -Ecole Nationale Supérieure de Mécanique et des Microtechniques ( ENSMM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Franche-Comté ( UFC ), Fonctions Optiques pour les Technologies de l'informatiON ( FOTON ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Université européenne de Bretagne ( UEB ) -Institut National des Sciences Appliquées - Rennes ( INSA Rennes ) -École Nationale Supérieure des Sciences Appliquées et de Technologie ( ENSSAT ) -Télécom Bretagne-Centre National de la Recherche Scientifique ( CNRS ), Caratterizzazione e Sviluppo di Materiali per la Fotonica e l'Optoelecttronica ( CSMFO ), CNR Istituto di Fotonica e Nanotecnologie [Trento] ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ) -Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Équipe Microondes et Opto-microondes pour Systèmes de Télécommunications ( LAAS-MOST ), MDF-Lab ( MDF-Lab, CNR-IFAC ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ) -Istituto di Fisica Applicata 'Nello Carrara' (IFAC), Alcatel-Thalès III-V lab ( III-V Lab ), THALES-ALCATEL, Centre National d'Etudes Spatiales ( CNES ), Centre National d'Etudes Spatiales Action R&T SHYRO R-S10/LN-0001-004, Maurizio Ferrari, Marian Marciniak, Giancarlo C. Righini, Tomasz Szoplik, Stefano Varas, SHYRO, THALES [France], Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Fonctions Optiques pour les Technologies de l'informatiON (FOTON), Université de Rennes (UR)-Université européenne de Bretagne - European University of Brittany (UEB)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Télécom Bretagne-Centre National de la Recherche Scientifique (CNRS), Caratterizzazione e Sviluppo di Materiali per la Fotonica e l'Optoelecttronica (CSMFO), CNR Istituto di Fotonica e Nanotecnologie [Trento] (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Équipe Microondes et Opto-microondes pour Systèmes de Télécommunications (LAAS-MOST), Istituto di Fisica Applicata 'Nello Carrara' (IFAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Alcatel-Thalès III-V lab (III-V Lab), THALES [France]-ALCATEL, Centre National d'Études Spatiales [Toulouse] (CNES), Maurizio Ferrari, Marian Marciniak, Giancarlo C. Righini, Tomasz Szoplik, Stefano Varas, Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université européenne de Bretagne - European University of Brittany (UEB)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-Télécom Bretagne, Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), and Consiglio Nazionale delle Ricerche [Roma] (CNR)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], [ PHYS.PHYS.PHYS-OPTICS ] Physics [physics]/Physics [physics]/Optics [physics.optics]
Abstract

accessible sur http://minap2012.fbk.eu; International audience; Optoelectronic Oscillators (OEOs) are an attractive alternative to electrical solutions for the generation of high spectral purity signal at high frequency. Indeed, carrying the microwave signal on an optical carrier offers the opportunity of long staorage time, with almost no dependence on signal frequency. For example, classical OEOs are based on kilometre long fiber delays and, in a relative simple setup, their performances exceed the ones of most microwave oscillators. However, the most promising OEOs architectures, in term of performances and integration level, are based on high Q optical resonators. After an introduction on the principle of OEOs and their various potential applications in advanced microwave systems, we will present recent results that we have obtained in this field.. First, the realization and characterization of silica, CaF2, MgF2 and LiNbO3 Whispering Gallery Modes (WGM) resonators with Q factors in the 10^8-10^9 range will be presented, together with related light coupling techniques for their practical use in OEOs demonstrations. Then the realization and characterization of fiber-ring resonators, that present Q factors exceeding 10^9 in a relatively simple architecture will be highlighted. Finally, dual-frequency laser sources that have been specifically realized for OEOs will be described.

Published
2012

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