Study of the Influence of Reference System in Surface Finishing Parameters Evaluation.

In the present paper the influence of the reference system with regard to the characterization of the surface finishing is analyzed. The effect of the reference system’s choice on the most representative surface finishing parameters (e.g. roughness average Ra and root mean square values Rq) is studied. The study can also be applied to their equivalent parameters in waviness and primary profiles. Based on ISO and ASME standards, three different types of regression lines (central, mean and orthogonal) are theoretically and experimentally analyzed, identifying the validity and applicability fields of each one depending on profile’s geometry. El presente trabajo realiza un estudio de la influencia que supone la elección del sistema de referencia en la determinación los valores de los parámetros más relevantes empleados en la caracterización del acabado superficial tales como la rugosidad media aritmética Ra o la rugosidad media cuadrática Rq y sus equivalentes en los perfiles de ondulación y completo. Partiendo de la definición establecida por las normas ISO y ASME, se analizan tres tipos de líneas de regresión cuadrática (línea central, línea media y línea ortogonal), delimitando los campos de validez y de aplicación de cada una de ellas en función de la geometría del perfil. Para ello se plantean diversos tipos de perfiles y se desarrolla un estudio teórico y experimental de los mismos

Neurological Tremor: Sensors, Signal Processing and Emerging Applications

Neurological tremor is the most common movement disorder, affecting more than 4% of elderly people. Tremor is a non linear and non stationary phenomenon, which is increasingly recognized. The issue of selection of sensors is central in the characterization of tremor. This paper reviews the state-of-the-art instrumentation and methods of signal processing for tremor occurring in humans. We describe the advantages and disadvantages of the most commonly used sensors, as well as the emerging wearable sensors being developed to assess tremor instantaneously. We discuss the current limitations and the future applications such as the integration of tremor sensors in BCIs (brain-computer interfaces) and the need for sensor fusion approaches for wearable solutions

A Network Model of Local Field Potential Activity in Essential Tremor and the Impact of Deep Brain Stimulation

Essential tremor (ET), a movement disorder characterised by an uncontrollable shaking of the affected body part, is often professed to be the most common movement disorder, affecting up to one percent of adults over 40 years of age. The precise cause of ET is unknown, however pathological oscillations of a network of a number of brain regions are implicated in leading to the disorder. Deep brain stimulation (DBS) is a clinical therapy used to alleviate the symptoms of a number of movement disorders. DBS involves the surgical implantation of electrodes into specific nuclei in the brain. For ET the targeted region is the ventralis intermedius (Vim) nucleus of the thalamus. Though DBS is effective for treating ET, the mechanism through which the therapeutic effect is obtained is not understood. To elucidate the mechanism underlying the pathological network activity and the effect of DBS on such activity, we take a computational modelling approach combined with electrophysiological data. The pathological brain activity was recorded intra-operatively via implanted DBS electrodes, whilst simultaneously recording muscle activity of the affected limbs. We modelled the network hypothesised to underlie ET using the Wilson-Cowan approach. The modelled network exhibited oscillatory behaviour within the tremor frequency range, as did our electrophysiological data. By applying a DBS-like input we suppressed these oscillations. This study shows that the dynamics of the ET network support oscillations at the tremor frequency and the application of a DBS-like input disrupts this activity, which could be one mechanism underlying the therapeutic benefit

Translation and validation of an extended German version of ID MigraineTM as a migraine screening tool

Abstract Background and purpose:Diagnosing a patient with headache as a migraineur is critical for state-of-the-art migrainemanagement. Screening tools are imperative means to improve the diagnostic yield in the primary care settings andspecialized clinics. This study aims to translate and assess the diagnostic accuracy of a German version of theID Migraine™as a widely used and efficient screening instrument. Methods: The Functional Assessment of Chronic Illness Therapy translation methodology was used to translate theoriginal three-itemID Migraine™, including a fourth question for aura, from the English language into the German language.Diagnostic accuracy of the GermanID Migraine™and predictors of false screening results were assessed among patientspresenting to a headache outpatient clinic of a tertiary care center in Germany over a 6-month period. Results: The translation procedure yielded a harmonized GermanID Migraine™and its diagnostic accuracy was assessedin 105 patients (80 female, 46.5+17.2 years of age), including 79 patients (75.2%) with migraine. The three-item GermanID Migraine™provides a sensitivity of 99%, specificity of 68%, and positive and negative predictive values of 90% and 95%,respectively, using a cutoff of� 2. Positive and negative predictive values in a general headache population are estimated tobe 74% and 98%, respectively. The aura question identified 18 out of 20 migraineurs with aura. Conclusions: The GermanID Migraine™is an accurate screening tool for migraine even in a challenging population of aspecialized outpatient clinic. Its diagnostic accuracy indicates a potential utility for screening in primary health care

Successful treatment of choreo-athetotic movements in a patient with an EEF1A2 gene variant

Pathogenic variants in EEF1A2 , a gene encoding a eukaryotic translation elongation factor, have been previously reported in pediatric cases of epileptic encephalopathy and intellectual disability. We report a case of a 17-year-old male with a prior history of epilepsy, autism, intellectual disability, and the abrupt onset of choreo-athetotic movements. The patient was diagnosed with an EEF1A2 variant by whole exome sequencing. His movement disorder responded dramatically to treatment with tetrabenazine. To the best of our knowledge, this is the first report of successful treatment of a hyperkinetic movement disorder in the setting of EEF1A2 mutation. A trial with tetrabenazine should be considered in cases with significant choreoathetosis