Miguel A. Velasco

Assistive Robots for Physical and Cognitive Rehabilitation in Cerebral Palsy

Cerebral palsy (CP) is one of the most severe disabilities in childhood and makes heavy demands on health, educational, and social services as well as on families and children themselves. The most frequently cited definition of CP is a disorder of posture and movement due to a defect or lesion in the immature brain, [1].

Positive and Negative Motor Signs of Head Motion in Cerebral Palsy: Assessment of Impairment and Task Performance

This paper analyzes the presence of positive and negative motor signs in people with cerebral palsy (CP). Positive motor signs are those that lead to involuntarily increased frequency or magnitude of muscle activity. Negative motor signs describe insufficient muscle activity or insufficient control of muscle activity. In this paper, a head-mounted alternative computer interface based on inertial technology was used to assess motor signs in seven users with CP. Task performance and control of posture was related to the impairment. There are no significant differences between users with CP and healthy control participants in the frequency domain of the head movement. Results suggest that this kind of motor disorders is not related to positive motor signs. Moreover, a control mode based on posture more than on movements is not optimum; an alternative control mode must be specially designed for users with poor postural control.

Human-computer interaction for users with cerebral palsy based on head orientation. Can cursor’s movement be modeled by Fitts’s law?

Abstract This paper presents an experiment to validate a head-mounted inertial interface for human-computer interaction (HCI) developed for people with cerebral palsy (CP). The method is based on Fitts’s law, an empirical model of human motor performance for aimed movements. Head motion is recorded in a series of goal-crossing tasks and a regression model of the movement time ( MT ) is estimated for each user. Values of R 2 above 0.9 are indicators of a strong correlation of those motion patterns with the linear model proposed by Fitts. The analysis of MT confirmed that head movements of users without disability follow Fitts’s law and showed that 3 users with CP (MACS IV and V) had the same behavior. There was a weaker correlation ( R 2 =0.839) for one individual with cervical dystonia and ballistic movements and no correlation for two users with cervical hypotonia and dyskinetic CP. Results show the impact of ballistic movements and poor postural control in computer interaction. They also provide the foundation for new interaction techniques to develop a universal computer interface for motor impaired users.

Accuracy and Precision of the Tobii X2-30 Eye-tracking under Non Ideal Conditions

This document describes a methodology for the measurement of accuracy and precision of a remote eye tracker, the Tobii X2-30, under non ideal condition. The test was performed with 10 people. The results are: 2.46 and 1.91 degrees for the accuracy and precision respectively. The results can be used to establish the target size on the screen.

Consequences of diverse evolutionary processes on american genetic gradients of modern humans

European genetic gradients of modern humans were initially interpreted as a consequence of the demic diffusion of expanding Neolithic farmers. However, recent studies showed that these gradients may also be influenced by other evolutionary processes such as population admixture or range contractions. Genetic gradients were observed in the Americas, although their specific evolutionary causes were not investigated. Here we extended the approach used to study genetic gradients in Europe to analyze the influence of diverse evolutionary scenarios on American genetic gradients. Using extensive computer simulations, we evaluated the impact of (i) admixture between expansion waves of modern humans, (ii) the presence of ice-sheets during the last glacial maximum (LGM) and (iii) long-distance dispersal (LDD) events, on the genetic gradients (detected by principal component analysis) of the entire continent, North America and South America. The specific simulation of North and South America showed that genetic gradients are usually orthogonal to the direction of range expansions—either expansions from Bering or posterior re-expansions to recolonize northern regions after ice sheets melting—and we suggest that they result from allele surfing processes. Conversely, our results on the entire continent show a northwest-southeast gradient obtained with any scenario, which we interpreted as a consequence of isolation by distance along the long length of the continent. These findings suggest that distinct genetic gradients can be detected at different regions of the Americas and that subcontinent regions present gradients more sensible to evolutionary and environmental factors (such as LDD and the LGM) than the whole continent.

Improvement of mouse controlling in Essential tremor by a tremor filter: A case report

The interaction with electronic devices is crucial in our technological society. Hand kinetic tremor complicates mouse driving in Essential tremor patients. To solve this issue some technological solutions are available and accessible online. We present a 71-year-old patient with prominent mouse controlling tremor who improved with one of these systems.

Metodología de Evaluación de Eye-trackers como Dispositivos de Acceso Alternativo para Personas con Parálisis Cerebral

Los autores agradecen a ATENPACE (Espana) y Colegio San Rafael (Espana) por su colaboracion, en especial a los participantes, sin ellos, este estudio no habria sido posible. A. Clemotte da las gracias a ITAIPU Binacional (Paraguay). Esta investigacion fue financiada por el Proyecto INTERPLAY (RTC-2014-1812-1) e INTERAAC (RTC-2015-4327-1).

BiMU—Inertial Sensors and Virtual Reality Games for the Rehabilitation of the Upper Limb in Cerebral Palsy

BiMU is a platform for computer access and rehabilitation of the upper limb through virtual reality (VR) games. It adapts to the motor and cognitive level of the user and its main goal is improving the efficiency of traditional therapies: reducing disability, increasing functional ability, and promoting social participation. BiMU’s peripheral consists of two wireless inertial measurement units that are attached to the forearm and upper arm and measure their movement. This information is used to control the movement of the cursor and perform click actions. In this paper, we present a pilot study that aimed to improve the quality of a specific movement: the forearm supination. The participants wore the BiMU system and played a series of VR games that recorded their performance. BiMU allows users computer access and a new mode of interactive occupational therapy. Moreover, it registers physical parameters and task performance measures that can be used by therapists to design customized rehabilitation protocols consisting of sequences of games to exercise specific functional movements and to monitor the evolution of the child throughout the work sessions.

A Novel Head Cursor Facilitation Technique for Cerebral Palsy: Functional and Clinical Implications

This work was possible thank to the projects NetMD (RTC-2015-3967-1), NeuroMOD (DPI2015-68664-C4-1-R), InterAAC (RTC-2015-4327-1), CP-Walker (DPI2012-39133-C03-03) and Interplay (RTC-2014-1812-1). The Spanish Ministry of Economy, Industry and Competitiveness financed all these projects.

Evaluation of Cervical Posture Improvement of Children with Cerebral Palsy After Physical Therapy with a HCI Based on Head Movements and Serious Videogames

This paper presents the preliminary results of a novel rehabilitation therapy for cervical and trunk control of children with cerebral palsy (CP). The therapy is based on the use of an inertial sensor that will be used to control a set of serious videogames with movements of the head. Ten users with CP participated in the study, in the experimental and control groups. Ten sessions of therapy provided improvements in head and trunk control that were higher in the experimental group for Visual Analogue Scale (VAS), Goal Attainment Scaling (GAS) and Trunk Control Measurement Scale (TCMS). Significant differences (27 % vs. 2 % of percentage improvement) were found between the experimental and control groups for TCMS (p < 0.05). The kinematic assessment shows that there are some improvements in active and passive range of motion, but no significant differences were found pre- and after-therapy. This new strategy, together with traditional rehabilitation therapies, could allow the child to reach maximum levels of function in the trunk and cervical regions.