Detecting affective states in virtual rehabilitation

Virtual rehabilitation supports motor training following stroke by means of tailored virtual environments. To optimize therapy outcome, virtual rehabilitation systems automatically adapt to the different patients' changing needs. Adaptation decisions should ideally be guided by both the observable performance and the hidden mind state of the user. We hypothesize that some affective aspects can be inferred from observable metrics. Here we present preliminary results of a classification exercise to decide on 4 states; tiredness, tension, pain and satisfaction. Descriptors of 3D hand movement and finger pressure were collected from 2 post-stroke participants while they practice on a virtual rehabilitation platform. Linear Support Vector Machine models were learnt to unfold a predictive relation between observation and the affective states considered. Initial results are promising (ROC Area under the curve (mean±std): 0.713 ± 0.137). Confirmation of these opens the door to incorporate surrogates of mind state into the algorithm deciding on therapy adaptation

Unobtrusive inference of affective states in virtual rehabilitation from upper limb motions: a feasibility study

Virtual rehabilitation environments may afford greater patient personalization if they could harness the patient's affective state. Four states: anxiety, pain, engagement and tiredness (either physical or psychological), were hypothesized to be inferable from observable metrics of hand location and gripping strength -relevant for rehabilitation-. Contributions are; (a) multiresolution classifier built from Semi-Naïve Bayesian classifiers, and (b) establishing predictive relations for the considered states from the motor proxies capitalizing on the proposed classifier with recognition levels sufficient for exploitation. 3D hand locations and gripping strength streams were recorded from 5 post-stroke patients whilst undergoing motor rehabilitation therapy administered through virtual rehabilitation along 10 sessions over 4 weeks. Features from the streams characterized the motor dynamics, while spontaneous manifestations of the states were labelled from concomitant videos by experts for supervised classification. The new classifier was compared against baseline support vector machine (SVM) and random forest (RF) with all three exhibiting comparable performances. Inference of the aforementioned states departing from chosen motor surrogates appears feasible, expediting increased personalization of virtual motor neurorehabilitation therapies

Herramienta de modelado disfuncional tridimensional basado en estudios de neuroimagen

El modelado disfuncional basado en estudios de neuroimagen mejora la comprensión de los cambios estructurales provocados ante la presencia de lesiones cerebrales. Actualmente, existen numerosas herramientas para el análisis y procesado de estudios de neuroimagen. Algunas de ellas, como el 3D Slicer, BrainVoyager y el FreeSurfer permiten la creación y navegación sobre modelos tridimensionales cerebrales sin alteraciones estructurales. Sin embargo, no se han detectado herramientas que permitan modelar tridimensionalmente lesiones a partir de estudios de neuroimagen, concretamente de estudios de resonancia magnética. El objetivo de este trabajo es el diseño de una metodología que permite la creación de este tipo de modelos y su visualización y navegación

Synthesis, reactivity, and catalytic activity of triangular ZrM2 (M = Rh, Ir) early-late heterobimetallic complexes

Reactions of the zirconium−sulfide metallocene anion [Cptt2ZrS2]2- (Cptt = η5-1,3-di-tert-butylcyclopentadienyl) with [{M(μ-Cl)(diolefin)}2 gave the d0−d8 complexes [Cptt2Zr(μ3-S)2{M(diolefin)}2] (M = Rh, diolefin = 2,5-norbornadiene (nbd) (1), 1,5-cyclooctadiene (cod); M = Ir, diolefin = cod) with a triangular ZrM2 core capped by two symmetrical μ3-sulfido ligands. The rhodium complexes [Cptt2Zr(μ3-S)2{Rh(diolefin)}2] (diolefin = tetrafluorobenzobarrelene (tfbb), nbd, cod) can also be prepared by the additive-deprotonation reactions of the mononuclear [Rh(acac)(diolefin)] (diolefin = nbd, tfbb) and the dinuclear [{Rh(μ-OH)(cod)}2] complexes with [Cptt2Zr(SH)2]. These compounds exist as two rotamers in solution due to a hindered rotation of the cyclopentadienyl rings and the relative disposition of the substituents of the Cptt groups in the sandwich moiety. The reaction of [Cptt2Zr(SH)2] with [Ir(acac)(cod)] gave the complex [Cptt(acac)Zr(μ3-S)2{Ir(cod)}2] (5) with release of HCptt and coordination of acetylacetonate to the zirconium center. Carbonylation of compounds 1 and 5 yielded [Cptt2Zr(μ3-S)2{Rh(CO)2}2] (6) and [Cptt(acac)Zr(μ3-S)2{Ir(CO)2}2], respectively, while the complexes [Cptt2Zr(μ3-S)2{M(CO)2}2] (M = Rh, Ir) resulted also from the reaction of [Cptt2Zr(SH)2] with (PPh3Bz)[MCl2(CO)2] in the presence of triethylamine. Reactions of the carbonyl complexes with 1 molar equiv of bis(diphenylphosphino)methane (dppm) gave the cisoid complexes [Cptt2Zr(μ3-S)2{M(CO)}2(μ-dppm)] (M = Rh (9), Ir) with evolution of carbon monoxide. Monodentate phosphites, P(OMe)3 and P(OPh)3, react with 6 to give mixtures of the transoid and cisoid isomers [Cptt2Zr(μ3-S)2{Rh(CO)(P(OR)3)}2], which also exhibit a restricted rotation of the Cptt rings. The molecular structures of complexes 6 and 9 have been determined by X-ray diffraction methods. Compound 6 in the presence of P-donor ligands, P(OMe)3, P(OPh)3, and PPh3, is a precursor of the catalyst for the hydroformylation of oct-1-ene under mild conditions of pressure and temperature. No Zr−Rh synergic effect is observed in this case, and the precursor breaks down after catalysis.We wish to thank Dirección General de Enseñanza Superior (DGES) and Diputación General de Aragón (DGA) for financial support (Projects PB88–0641 and P051/2000, respectively). Fellowships from the Ministerio de Educación y Cultura (M.A.F.H.-G.), Diputación General de Aragón (I.T.D.) and Programa CYTED (A.B.R.) are gratefully acknowledged.Peer Reviewe

Novel gem-dithiolato-bridged rhodium hydroformylation catalysts: Bridging the gap in dinuclear rhodium thiolate chemistry

The direct protonation of the bridging hydroxo ligands in [Rh(μ-OH)(cod)]2 by 1,1-dimercaptocyclohexane [Chxn(SH) 2] yields the gem-dithiolato-bridged compound [Rh2(μ- S2Chxn)-(cod)2] (1). The dinuclear framework in 1 is supported by a 1,1-cyclohexanedithiolato ligand exhibiting a 1:2κ2S,1:2κ2S′ coordination mode. Compound 1 is an active catalyst precursor in the presence of P-donor ligands for the hydroformylation of oct-1-ene under mild conditions of pressure and temperature (100 PSI, 353 K). The best results were obtained with phosphite ligands as modifying ligands. An aldehyde selectivity of 97 %, a regioselectivity towards the linear aldehyde of 81 %, and turnover frequencies of up to 198 h-1 were obtained with the catalytic system 1/P(OMe)3. The dinuclear compound [Rh2(μ-S 2Chxn)(CO)2(PPh3)2] (2) was isolated from the catalytic solutions resulting from the system 1/PPh3 and was characterized by spectroscopic means and by X-ray diffraction to be the frans isomer. The mixed-ligand dinuclear complexes 2 and [Rh2(μ- S2Chxn)(CO)2(PCy3)2] (3) (Cy = cyclohexyl) were independently prepared by reaction of Chxn(SH)2 with the mononuclear complexes [Rh(acac)(CO)-(PR3)] in the appropriate molar ratio.The financial support from Ministerio de Educación y Ciencia (MEC/FEDER) is gratefully acknowledged (Project CTQ2006-03973/BQU and Factoría de Cristalización, CONSOLIDER INGENIO-2010). A. B. R. thanks the Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED, Project V.9) for a fellowship. A. J. P. thanks to Fonacit-Venezuela (S1-2002000260) for financial support.Peer Reviewe