External auditory cues stimulate motor related areas of the brain, activating motor ways parallel to the basal ganglia circuits and providing a temporary pattern for gait. In effect, patients may re-learn motor skills mediated by compensatory neuroplasticity mechanisms. However, long term functional gains are dependent on the nature of the pathology, follow-up is usually limited and reinforcement by healthcare professionals is crucial. Aiming to cope with these challenges, several researches and device implementations provide auditory or visual stimulation to improve Parkinsonian gait pattern, inside and outside clinical scenarios. The current work presents a semiautomated strategy for spatio-temporal feature extraction to study the relations between auditory temporal stimulation and spatiotemporal gait response. A protocol for auditory stimulation was built to evaluate the integrability of the strategy in the clinic practice. The method was evaluated in transversal measurement with an exploratory group of people with Parkinson’s (n = 12 in stage 1, 2 and 3) and control subjects (n =6). The result showed a strong linear relation between auditory stimulation and cadence response in control subjects (R=0.98 ±0.008) and PD subject in stage 2 (R=0.95 ±0.03) and stage 3 (R=0.89 ±0.05). Normalized step length showed a variable response between low and high gait velocity (0.2> R >0.97). The correlation between normalized mean velocity and stimulus was strong in all PD stage 2 (R>0.96) PD stage 3 (R>0.84) and controls (R>0.91) for all experimental conditions. Among participants, the largest variation from baseline was found in PD subject in stage 3 (53.61 ±39.2 step/min, 0.12 ± 0.06 in step length and 0.33 ± 0.16 in mean velocity). In this group these values were higher than the own baseline. These variations are related with direct effect of metronome frequency on cadence and velocity. The variation of step length involves different regulation strategies and could need others specific external cues. In conclusion the current protocol (and their selected parameters, kind of sound time for training, step of variation, range of variation) provide a suitable gait facilitation method specially for patients with the highest gait disturbance (stage 2 and 3). The method should be adjusted for initial stages and evaluated in a rehabilitation program.
Several approaches using auditory feedback have been proposed to improve gait rehabilitation in Parkinson Disease. Despite auditory cues have shown to be useful, there are still unanswered questions about their optimal usage regarding parameters like frequency, number of beats and their integration with rehabilitation protocols, among others. Most approaches have attempted to resolve these questions by measuring their direct effect on spatiotemporal gait variables. However, few studies have assessed how synchronized the auditory feedback and the gait pattern are. The main goal was to quantify synchronization between the gait temporal patterns and the auditory stimuli. The group of participants consisted of seven (7) healthy subjects, aged between 50-70 years (average 57.28, ± 5.87 years), with average height of 1.64±0.09m and independent community ambulation. Each candidate was asked to sign an informed consent, given their good cognitive conditions for understanding the nature and purpose of the study. Participants were instructed to follow the sounds provided by a metronome. Feet tracking yielded the temporal gait pattern. The temporal coherence metric was developed to evaluate synchronization between audio signal and subject motion, in terms of phase shift (π radian). Results show a good fit to auditory stimulus in metronome rates between 140-150 and 60-80 beats/min (bpm) for the selected participants. A lower temporal coherence was observed at the beginning and the end of the test. The proposed metric allows quantification of the temporal coherence between gait and auditory cues in healthy elder subjects. Other exploratory trials should be directed to evaluate the temporal coherence between auditory stimuli and generated movements in population with Parkinson Disease.
People with Complex Communication Needs (CCN) face difficulties to communicate their ideas, feelings and needs. Augmentative and Alternative Communication (AAC) approaches aim to provide support to enhance socialization of these individuals. However, there are many limitations in current applications related with systems operation, target scenarios and language consistency. This work presents an AAC approach to enhance produced messages by applying elements of Natural Language Generation. Specifically, a Spanish language engine, composed of a grammar ontology and a set of linguistic rules, is proposed to improve the naturalness in the communication process, when persons with CCN tell stories about their daily activities to non-disabled receivers. The assessment of the proposed method confirms the validity of the model to improve messages quality.
Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.
Virtual microscopy (VM) facilitates visualization and deployment of histopathological virtual slides (VS), a useful tool for education, research and diagnosis. In recent years, it has become popular, yet its use is still limited basically because of the very large sizes of VS, typically of the order of gigabytes. Such volume of data requires efficacious and efficient strategies to access the VS content. In an educative or research scenario, several users may require to access and interact with VS at the same time, so, due to large data size, a very expensive and powerful infrastructure is usually required. This article introduces a novel JPEG2000-based service oriented architecture for streaming and visualizing very large images under scalable strategies, which in addition need not require very specialized infrastructure. Results suggest that the proposed architecture enables transmission and simultaneous visualization of large images, while it is efficient using resources and offering users proper response times.
Modern Medical diagnoses are more and more based upon interactivity with different kinds of data. Images
are at the very base of these diagnosis policies and require high degrees of interaction, a requirement that most
compression standards do not meet since for achieving this, high granularity levels are needed. JPEG2000 (J2K)
has lately arisen as a compression standard that tackles with these challenges, allowing appropriate compression
rates and efficient access to data, i.e. random spatial access at any resolution and with any desired quality.
Based on the J2K standard method, this article presents a 3D compression method which adapts the J2K simplicity
handling of 2D data and includes the 3D information with no modification of the structures used in 2D
implementations. The proposed method was compared with a conventional J2K implementation in 2D, using
3D and 4D data, showing that the 3D strategy saves around a 12 % of hard disk space when compared to the
conventional 2D implementation.