Spike detection algorithm automatically adapted to individual patients applied to spike-and-wave percentage quantification.

OBJECTIVE: To report an innovative spike detection algorithm that tailors its detection to the patient. Interictal epileptiform activity quantification was accomplished in the setting of epileptic syndromes with continuous spike and waves during slow sleep, which is a time-consuming task for the EEG analysis. METHODS: The algorithm works in three steps. Firstly, a first spike detection is made with generic parameters. Secondly, the detected spikes are used to tailor the detection algorithm to the patient; and thirdly, the resulting patient-specific detection algorithm is used to analyze individual patient with high-quality detection. Therefore, the algorithm produces a patient-specific template -hence exhibiting improved performance metrics, without the need of a priori knowledge from the experts. RESULTS: The system was first evaluated for EEG of three patients, against the scoring of three EEG experts, demonstrating similar performance. Later, it was evaluated against the spike and wave percentage evaluation of another expert for 17 additional records. The difference between the two evaluations was 4.4% on average, which is almost the same as the interexpert difference (4.7%). CONCLUSIONS: We designed a fully automated and efficient spike detection algorithm, which is liable to trim down the specialist's diagnostic time.

[Botulism: prevention, clinical diagnostics, therapy and possible threat]. / Botulismus: Prävention, Diagnostik, Therapie und mögliche Bedrohungslagen.

In times of increased terrorist threat health professionals need to be prepared for bioterrorist events. The goal must be to give doctors an overview over the current state of knowledge and risk assessment of botulinum toxin. This review is based on Information gathered by a systematic analysis of the literature and by contacting experts. The toxicity of botulinum toxin exceeds any other known natural toxin. Clinical features of botulism consist of an acute, afebrile symmetrical and descending paralysis, regardless of the route of exposure, with normal mental status, sensory functions and electrolyte values. The initial diagnosis is often wrong in individual cases of botulism, but clusters with typical symptoms and two or more cases usually provide the diagnosis. Current treatment is primarily supportive care, respiratory support and antitoxin administration. Early application of antitoxin can limit the extent of the paralysis, but will not reverse it. Antitoxin for adult patients is of equine origin, while children in the USA can be treated with a recently developed human antitoxin. A pentavalent toxoid vaccine is available for persons at high risk of exposure. Botulinum toxin is easily extracted and ubiquitously available. These two features, together with the high toxicity, makes misuse easy. Misuse will continue to occur. Although a rare disease in Western Europe, botulism should be included in the differential diagnosis in patients with specific symptoms of paralysis. There is the potential threat of deliberate release of botulinum toxin. For this reason every outbreak of botulism must be assessed for any possible links to terrorism.

Reduction of power line interference using active electrodes and a driven-right-leg circuit in electroencephalographic recording with a minimum number of electrodes.

Unwanted power line interference is one of the most common problems in electroencephalographic recording. This paper examines how the use of active electrodes together with a driven-right-leg circuit can significantly improve interference reduction, even when the same electrode is used for common and reference which is attractive because it saves an electrode. General conclusions about the active electrodes and the driven-right-leg circuits were obtained thanks to a prototype that uses the same electrode for both common and reference. Measurements were performed both on a subject and on an electrical equivalent model.

Smoke-free cafe in an unregulated European city: highly welcomed and economically successful.

OBJECTIVE: In a unique setting with two identical cafes, which only differed in their smoking ordinances, this study assessed the influence of smoking policies on the choice of the cafe, investigated regulatory preferences among customers, and evaluated the claim that smoking cafes have better sales performance in a city without smoking bans. METHODS: In a parallel assessment, customers of both cafes answered a questionnaire. Sales were compared and air pollutants were measured to confirm air quality differences. RESULTS: The two customer groups (n = 177) differed only with regard to smoking status (p < 0.01). The smoking regulation was the most often cited selection criterion (83%). In the non-smoking café, 89% indicated that they were usually annoyed by smoke in coffee houses, and 62% would avoid or leave cafes for this reason. Two thirds stated that all cafe/restaurants should offer the opportunity of a smoke-free environment. However, almost half stated that mandatory regulations are not needed and that customers should make individual arrangements based on tolerance and courtesy. Those who were informed about the health effects of secondhand smoke were more likely to call for clear policies. Whereas sales showed no differences, tips were 22% (p < 0.001) higher in the non-smoking cafe. CONCLUSION: In a generation raised in smoking friendly environments, customers paradoxically ask for a landmark shift towards smoke-free opportunities, while substantially adhering to the tobacco industry paradigm of promoting "tolerance" rather than smoke-free policies. Given the clear preference of a large number of customers, hospitality businesses could, however, greatly profit from offering smoke-free environments even in the absence of regulatory policies.

X- and Q-band electron paramagnetic resonance of CO2- in hydroxyapatite single crystals.

Both X- and Q-band electron paramagnetic resonance (EPR) research has been conducted using slightly carbonated hydroxyapatite (HAp) single crystals after exposure to ionizing radiation. Below a temperature of 90 K, O(-) and CO(2-) radicals were detected, whereas at room temperature only CO(2-) spectra could be observed. The O(-) ion has previously been investigated in high-purity HAp single crystals, whereas EPR spectra of CO(2-) in HAp single crystals have not been reported. Both paramagnetic defects exhibit EPR angular variations in planes containing the c axis of the crystal from which spin Hamiltonian parameters were derived. Arguments are given for the presence of two CO(2-) defects in the irradiated HAp single crystals.

Spatial variability of different fractions of particulate matter within an urban environment and between urban and rural sites.

The spatial variability of different fractions of particulate matter (PM) was investigated in the city of Basel, Switzerland, based on measurements performed throughout 1997 with a mobile monitoring station at six sites and permanently recorded measurements from a fixed site. Additionally, PM10 measurements from the following year, which were concurrently recorded at two urban and two rural sites, were compared. Generally, the spatial variability of PM4, PM10, and total suspended particulates (TSP) within this Swiss urban environment (area = 36 km2) was rather limited. With the exception of one site in a street canyon next to a traffic light, traffic density had only a weak tendency to increase the levels of PM. Mean PM10 concentration at six sites with different traffic densities was in the range of less than +/- 10% of the mean urban PM10 level. However, comparing the mean PM levels on workdays to that on weekends indicated that the impact of human activities, including traffic, on ambient PM levels may be considerable. Differences in the daily PM10 concentrations between urban and more elevated rural sites were strongly influenced by the stability of the atmosphere. In summer, when no persistent surface inversions exist, differences between urban and rural sites were rather small. It can therefore be concluded that spatial variability of annual mean PM concentration between urban and rural sites in the Basel area may more likely be caused by varying altitude than by distance to the city center.

Validity of ambient levels of fine particles as surrogate for personal exposure to outdoor air pollution--results of the European EXPOLIS-EAS Study (Swiss Center Basel).

To evaluate the validity of fixed-site fine particle levels as exposure surrogates in air pollution epidemiology, we considered four indicator groups: (1) PM2.5 total mass concentrations, (2) sulfur and potassium for regional air pollution, (3) lead and bromine for traffic-related particles, and (4) calcium for crustal particles. Using data from the European EXPOLIS (Air Pollution Exposure Distribution within Adult Urban Populations in Europe) study, we assessed the associations between 48-hr personal exposures and home outdoor levels of the indicators. Furthermore, within-city variability of fine particle levels was evaluated. Personal exposures to PM2.5 mass were not correlated to corresponding home outdoor levels (n = 44, rSpearman (Sp) = 0.07). In the group reporting neither relevant indoor sources nor relevant activities, personal exposures and home outdoor levels of sulfur were highly correlated (n = 40, rSp = 0.85). In contrast, the associations were weaker for traffic (Pb: n = 44, rSp = 0.53; Br: n = 44, rSp = 0.21) and crustal (Ca: n = 44, rSp = 0.12) indicators. This contrast is consistent with spatially homogeneous regional pollution and higher spatial variability of traffic and crustal indicators observed in Basel, Switzerland. We conclude that for regional air pollution, fixed-site fine particle levels are valid exposure surrogates. For source-specific exposures, however, fixed-site data are probably not the optimal measure. Still, in air pollution epidemiology, ambient PM2.5 levels may be more appropriate exposure estimates than total personal PM2.5 exposure, since the latter reflects a mixture of indoor and outdoor sources.

Measurement of thoracoabdominal asynchrony: importance of sensor sensitivity to cross section deformations.

Discrepancies in the assessment of thoracoabdominal asynchrony are observed depending on the choice of respiratory movement sensors. We test the hypothesis that these discrepancies are due to a different dependence of the sensors on cross-sectional perimeter and area variations of the chest wall. First, we study the phase shift between perimeter and area (Phi(PA)) for an elliptical model, which is deformed by sinusoidal changes of its principal axes. We show that perimeter and area vary sinusoidally in the physiological range of deformations, and we discuss how Phi(PA) depends on the ellipticity of the cross section, on the ratio of transverse and dorsoventral movement amplitudes, and on their phase difference. Second, we compute the relationship between perimeter, area, and the output of the inductive sensor, and we proceed by comparing inductive plethysmography with strain gauges for several cross section deformations. We demonstrate that both sensors can provide different phase information for identical cross section deformations and, hence, can estimate thoracoabdominal asynchrony differently. Furthermore, the complex dependence of the inductive sensor on perimeter and area warns against this sensor for the evaluation of thoracoabdominal asynchrony.