Digital Butterworth filter for subtracting noise from low magnitude surface electromyogram

This work presents a digital filter designed to delimitate the frequency band of surface electromyograms (EMG) and remove the mains noise and its harmonics, focusing the signal analysis during reduced muscle activity. A Butterworth filter was designed as the frequency-domain product of a second order, high-pass filter with cutoff frequency 10 Hz, an eighth order low-pass filter, with cutoff at 400 Hz and six stop-band filters, second order, centered at the 60 Hz mains noise and its harmonics until 360 Hz. The resulting filter was applied in both direct and reverse directions of the signals to avoid phase distortions. The performance was evaluated with a simulated EMG signal with additive noise in multiples of 60 Hz. A qualitative assessment was made with real EMG data, acquired from 16 subjects, with age from 20 to 32 years. Subjects were positioned in orthostatic position during 21s, being only the last second analyzed to assure stationarity. EMG were collected by Ag/AgCl electrodes on right lateral gastrocnemius, amplified with gain 5000, filtered in the band from 10 Hz to 1 kHz, and thus digitized with 2ksamples/s. The filter effectively removed the mains noise components, with attenuations greater than 96.6%. The attenuation of the simulated signal at frequencies below 15 Hz and at 60 Hz caused only a small reduction of total power, preserving the original spectrum. Thus, the filter resulted suitable to the proposed application.     

Evaluation of thermal and mechanical properties of rubber compositions based on SBR extended with safe oils

The extender oil usually employed in compositions of rubbers based on styrene and butadiene (SBR) 1712 is the distilled aromatic extract (DAE). In this work, this oil was substituted by oils with low levels of polycyclic aromatic hydrocarbons (PAHs): treated residual aromatic extract (TRAE) and two naphthenic oils from different suppliers (HN1 and HN2). This substitution was performed in response to REACH Regulation (EC No. 1907/2006 European Parliament and the Council of December 18, 2006, Annex XVII), which state that the sum of individual PAHs should be below 10 mg/kg and the levels of benzo (a) pyrene (BaP) should not exceed 1 mg/kg. Infrared spectroscopy was employed to characterize the structure of crude oils and respective SBR compositions. Thermal properties of the materials were evaluated by thermogravimetry and differential scanning calorimetry. Mechanical properties as tension tests, hardness, abrasion resistance, and resilience were also determined. The final results showed that it is possible to replace the extender oil DAE for any of the oils tested, specially the naphthenic HN1, without any loss of the properties evaluated in this study for the SBR compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Assessing blood flow control through a bootstrap method

In order to assess blood flow control, the relationship between blood pressure and blood flow can be modeled by linear filters. We present a bootstrap method, which allows the statistical analysis of an index of blood flow control that is obtained from constrained system identification using an established set of pre-defined filters.     

Reduction of electromyographic noise in the signal-averaged electrocardiogram by spectral decomposition

This paper proposes a technique to improve the quality of high-resolution electrocardiogram by weighting the coherent average of beats by a function of the energy of the corrupting myoelectric noise, prior to subsequent detection of ventricular late potentials. The results obtained with 20 patients indicate the method requires fewer beats than conventional nonweighted average to achieve the same noise level.     

3D reconstruction of cultural heritages: Challenges and advances on precise mesh integration

Several methods perform the integration of multiple range scans of an object aiming the generation of a reconstructed triangle mesh; however, achieving high fidelity digital reconstructions is still a challenge. That is mostly due to the existence of outliers in the acquired range data, and their harmful effects on the integration algorithms. In this work, we first discuss artifacts usually found on real range data captured with 3D scanners based on laser triangulation. Following that there is the assessment of two widely used volumetric integration techniques (VRIP and Consensus Surface) and our suggested improvements. We also present a novel, hybrid approach that combines strengths from both VRIP and Consensus Surface, named IMAGO Volumetric Integration Algorithm (IVIA). Our novel algorithm adds new ideas while improving the detection and elimination of artifacts. Further, IVIA works in close cooperation with the subsequent hole filling process, which greatly improves the overall quality of the generated 3D models. Our technique leads to better results when assessed in different situations, when compared to VRIP, Consensus Surface, and also to a well known state-of-the-art surface-based method, Poisson Surface Reconstruction.     

Radiotherapy in Ewing's sarcoma and PNET of the chest wall: results of the trials CESS 81, CESS 86 and EICESS 92

PURPOSE: Treatment results and the pattern of relapse were evaluated in the multimodal treatment of Ewing's sarcomas of the chest wall. METHODS AND MATERIALS: In a retrospective analysis, 114 patients with non-metastatic Ewing's sarcoma of the chest wall were evaluated. They were treated in the CESS 81, CESS 86, or EICESS 92 studies between January 1981 and December 1993. The treatment consisted of polychemotherapy (VACA, VAIA, or EVAIA) and local therapy, either surgery alone (14 patients), radiotherapy alone (28 patients) or a combination of both (71 patients). The median follow-up was 46.6 months (range 5-170). A relapse analysis for all patients with local or combined relapses was performed. RESULTS: Overall survival was 60% after 5 years, event-free survival was 50%. Thirty-seven patients had a systemic relapse (32.4%), 11 patients had a local relapse alone (9.6%), and 3 patients had a combined local and systemic relapse (2.6%). The risk to relapse locally after 5 years was 0% after surgery alone, 19% after radiation alone, and 19% after postoperative irradiation. None of the 8 patients with preoperative irradiation have failed locally so far. With the introduction of central radiotherapy planning in CESS 86, local control of irradiated patients improved. Ten of 14 patients with local failure could be evaluated in the relapse analysis: 3 patients had an in-field relapse, 4 patients had a marginal relapse, 2 patients had a relapse outside the radiation fields, and 1 patient failed with pleural dissemination. Six treatment deviations were observed. CONCLUSION: Local control was best after surgery alone in a positively selected group of patients. Local control after radiation or combined radiation and surgery was good. With diligent performance of radiotherapy, it will be possible to further improve the results in the radiotherapy group.     

Human atrial natriuretic peptide in patients with type 1 diabetes mellitus: is it related to the development of diabetic nephropathy?

There is controversy as to whether increased plasma levels of human atrial natriuretic peptide (hANP) in patients with type 1 diabetes mellitus may contribute to the development of diabetic nephropathy. Therefore, we decided to conduct two studies to examine the relationship of hANP levels to urinary albumin excretion and blood pressure. In a cross-sectional study, 83 randomly selected type 1 diabetic patients were investigated. 19 of the patients had increased urinary albumin excretion. 45 healthy volunteers served as controls. In a longitudinal study, 19 type 1 diabetic patients were examined for one year at monthly intervals. An increased risk of eventually developing diabetic nephropathy was identified in 7 out of these patients by repeatedly revealing increased urinary albumin excretion. On the average, hANP levels were increased in type 1 diabetic patients in comparison to controls (P < 0.001). In both studies, hANP levels were positively related (P < 0.05) to mean arterial blood pressure. There was no correlation between hANP levels and metabolic control. hANP levels lay within normal range irrespective of normal or elevated urinary albumin excretion provided that mean arterial blood pressure was normal. In the longitudinal study, increased urinary albumin and alpha-1-microglobulin excretion preceded the increase in both hANP levels and mean arterial blood pressure. Although hANP levels were evidently not related to the disease mechanisms of early diabetic nephropathy, it is tempting to speculate that hANP may contribute to the vicious circle connecting diabetic kidney disease to hypertension once that its levels are increased by elevated blood pressure.     

Anthocyanins: optimisation of extraction from Cabernet Sauvignon grapes,microcapsulation and stability in soft drink

The aim of this study was to establish the optimum conditions for the extraction of anthocyanins from Cabernet Sauvignon (Vitis vinifera L.) grapes using the response surface methodology and to evaluate the stability of these anthocyanins encapsulated with different carrier agents in an isotonic soft drink system under different light and temperature conditions. The extraction process was optimised with the response surface methodology to obtain the highest anthocyanin concentration (40 mL of ethanol:1.5 N HCL (85:15) as solvent, extraction time 29.4 h at pH 2.4). The degradation of the anthocyanins followed first‐order kinetics in the situations evaluated. Maltodextrin, maltodextrin/γ‐cyclodextrin and maltodextrin/arabic gum were tested as carrier agents and the combination of maltodextrin/arabic gum presented the longest half‐life time and lowest degradation constant for all the conditions evaluated. The formation of microcapsules was observed through scanning electron microscopy.     

Reliability of roughness measurements using contact stylus instruments with particular reference to results of recent research at the Physikalisch-Technische bundesanstalt

Even today international comparison measurements of surface roughness show differences of 40% and more, as they did more than 10 years ago. However, within the framework of the Deutscher Kalibrierdienst, differences occurring in comparison measurements do not exceed 5%. At the end of 1982, a project of the European Communities was started for the purpose of also carrying out comparison measurements yielding small differences. The prerequisites are the following: clearly defined surface roughness parameters including details of the measurement conditions required and calibration and testing of the contact stylus instruments before the comparison measurements are made.In recent years the contacting process, the interaction between stylus and surface, has been the subject of very thorough investigations at the Physikalisch-Technische Bundesanstalt. Elastic and plastic deformations of the surface were examined. The parameters of influence are the geometry of the stylus tip and of the surface under examination, the properties of the materials, the static and dynamic measuring forces and the rate of feed. Calculation methods for optimizing these parameters are stated in order to keep the resulting measurement errors as small as possible. A new contactless measuring method is described which is based on the evaluation of scanning electron microscopy stereo pairs. An error analysis makes precision measurements possible which up to now could not be carried out at all. Examples examined have shown that sometimes, particularly on finely ground surfaces, measurements with contact stylus instruments on surfaces with R_z values below 1 μm can be very significantly in error.