A real-time stress classification system based on arousal analysis of the nervous system by an F-state machine.

BACKGROUND AND OBJECTIVE: Detection and labelling of an increment in the human stress level is a contribution focused principally on improving the quality of life of people. This work is aimed to develop a biophysical real-time stress identification and classification system, analysing two noninvasive signals, the galvanic skin response and the heart rate variability. METHODS: An experimental procedure was designed and configured in order to elicit a stressful situation that is similar to those found in real cases. A total of 166 subjects participated in this experimental stage. The set of registered signals of each subject was considered as one experiment. A preliminary qualitative analysis of the signals collected was made, based on previous counselling received from neurophysiologists and psychologists. This study revealed a relationship between changes in the temporal signals and the induced stress states in each subject. To identify and classify such states, a subsequent quantitative analysis was performed in order to determine specific numerical information related to the above mentioned relationship. This second analysis gives the particular details to design the finally proposed classification algorithm, based on a Finite State Machine. RESULTS: The proposed system is able to classify the detected stress stages at three levels: low, medium, and high. Furthermore, the system identifies persistent stress situations or momentary alerts, depending on the subject's arousal. The system reaches an F1 score of 0.984 in the case of high level, an F1 score of 0.970 for medium level, and an F1 score of 0.943 for low level. CONCLUSION: The resulting system is able to detect and classify different stress stages only based on two non invasive signals. These signals can be collected in people during their monitoring and be processed in a real-time sense, as the system can be previously preconfigured. Therefore, it could easily be implemented in a wearable prototype that could be worn by end users without feeling to be monitored. Besides, due to its low computational, the computation of the signals slopes is easy to do and its deployment in real-time applications is feasible.

Robot trajectories comparison: a statistical approach.

The task of planning a collision-free trajectory from a start to a goal position is fundamental for an autonomous mobile robot. Although path planning has been extensively investigated since the beginning of robotics, there is no agreement on how to measure the performance of a motion algorithm. This paper presents a new approach to perform robot trajectories comparison that could be applied to any kind of trajectories and in both simulated and real environments. Given an initial set of features, it automatically selects the most significant ones and performs a statistical comparison using them. Additionally, a graphical data visualization named polygraph which helps to better understand the obtained results is provided. The proposed method has been applied, as an example, to compare two different motion planners, FM(2) and WaveFront, using different environments, robots, and local planners.

Embolismo del líquido amniótico: caso clínico y revisión de la literatura / No disponible

El embolismo de líquido amniótico (ELA) es un síndrome poco frecuente pero con fatales resultados que se produce principalmente durante el parto o en el posparto inmediato. Se presenta un caso de una paciente de 33 años sin antecedentes médicos importantes. Coincidiendo rotura de la bolsa amniótica, comienza con sensación de mareo, que mejora con decúbito lateral izquierdo y sueroterapia. Tras el nacimiento del recién nacido, la paciente presenta parada cardiorrespiratoria de la que tras 45min de reanimación cardiopulmonar se recupera pero presenta hemorragia posparto por atonía que revierte parcialmente con la administración de metilergometrina y misoprostol ni con la colocación de balón de Bakri. Debido a la sospecha de coagulación intravascular diseminada se transfunden 8 concentrados de hematíes, 3 concentrados de plasma y 2.000 UI de octaplex; y se la traslada a la UCI de nuestro hospital con el diagnóstico de sospecha de embolismo de líquido amniótico. Al llegar a nuestro centro presenta metrorragia activa y orina hematúrica; con una hemoglobina de 7,9, trombopenia y coagulopatía, precisando transfusión de concentrados de hematíes, un pool de plaquetas, 750 cc de plasma, fibrinógeno y factor vii de la coagulación. Tras la corrección de la coagulopatía, cesa el sangrado y la paciente evoluciona, y es dada de alta a los 6 días (AU)

Amniotic fluid embolism (AFE) is a rare but fatal syndrome occurring mostly during delivery or immediately postpartum. We report the case of a 33-year-old patient with no (..) (AU)

Assessment of regional metal levels in ambient air by statistical regression models.

The assessment of the particulate matter (PM) levels and its constituents presented in the atmosphere is an important requirement of the air quality management and air pollution abatement. The heavy metal levels in PM10 are commonly evaluated by experimental measurements; nevertheless, the EC Directives also allow the Regional Governments to estimate the regulated metal levels (Pb in Directive 2008/50/EC and As, Ni and Cd in Directive 2004/107/EC) by objective estimation and modelling techniques. These techniques are proper alternatives to the experimental determination because the required analysis and/or the number of required sampling sites are reduced. The present work aims to estimate the annual levels of regulated heavy metals by means of multivariate linear regression (MLR) and principal component regression (PCR) at four sites in the Cantabria region (Northern Spain). Since the objective estimation techniques may only be applied when the regulated metal concentrations are below to the lower assessment threshold, a previous evaluation of the determined annual levels of heavy metals is conducted to test the fulfilment of the EC Directives requirements. At the four studied sites, the results show that the objective estimations are allowed alternatives to the experimental determination. The annual average metal concentrations are well estimated by the MLR technique in all the studied sites; furthermore, the EC quality requirements for the objective estimations are fulfilled by the developed statistical MLR models. Hence these estimations may be used by Regional Governments as a proper alternative to the experimental measurements for the regulated metal levels assessment.

Impact of the global economic crisis on metal levels in particulate matter (PM) at an urban area in the Cantabria Region (Northern Spain).

Air pollution by particulate matter is well linked with anthropogenic activities; the global economic crisis that broke out in the last year may be a proper indicator of this close relationship. Some economic indicators show the regional effects of the crisis on the Cantabria Region. The present work aims to evaluate the impact of the economic crisis on PM10 levels and composition at the major city of the region, Santander. Some metals linked to anthropogenic activities were measured at Santander and studied by Positive Matrix Factorization; this statistical analysis allowed to identify three main factors: urban background, industrial and molybdenum-related factor. The main results show that the temporal trend of the levels of the industrial tracers found in the present study are well agree with the evolution of the studied economic indicators; nevertheless, the urban background tracers and PM10 concentration levels are not well correlated with the studied economic indicators.

[Inferior vena cava obstruction syndrome caused by urinary retention]. / Síndrome de obstrucción de vena cava inferior por globo vesical.

OBJECTIVE: To report an unusual case of inferior vena cava obstruction secondary to urinary retention. METHODS/RESULTS: A 72-year-old male patient with a history of bilateral inguinal hernia and a recent hip surgery, presented with deep venous thrombosis in the left leg. A CT scan disclosed significant thickening of the bladder wall and grade III-IV hypertrophy of the prostate. Abdominal ultrasound disclosed a cystic mass compressing the vena cava and moderate ureterohydronephrosis. Edema spontaneously resolved following insertion of a urethral catheter and renal function returned to normal. CONCLUSION: Obstruction of the inferior vena cava secondary to an enlarged bladder is rare. To our knowledge only two such cases have been reported in the literature. In the case described herein, urinary retention may have been exacerbated by prostatic hypertrophy, anesthesia and bed confinement due to hip surgery.

[The determinants of exercise tolerance in patients with hypertensive cardiopathy]. / Determinantes de la tolerancia al ejercicio en pacientes con cardiopatía hipertensiva.

A study was made of 45 patients with arterial hypertension, no prior angina or myocardial infarction, mean age 64 +/- 5 years, and ejection fraction > 50%. Twenty (group I) had congestive heart failure while 25 (group II) were asymptomatic. Testing following remission of symptoms revealed impaired exercise tolerance (VO2 max < 20 ml/kg/min) in 22 (subgroup A-80% from group I), and normal tolerance in 23 (subgroup B). Of ventricular function indexes, only peak filling rate correlated significantly with VO2 max (r = 0.65). Of 32 patients with thallium-201 negative in ergometric tests, the 12 in subgroup A had a higher degree of hypertrophy (p > 0.01). Nine thallium-positive patients had lower VO2 max (p > 0.05) than did 17 thallium-negative patients with a similar degree of hypertrophy. Thus, in hypertensive patients, exercise tolerance depends on prior congestive heart failure, diastolic dysfunction, degree of hypertrophy and silent regional ischemia.

Comparative study of gallopamil versus nifedipine in patients with ischemic heart disease.

In order to compare the anti-ischemic activity of gallopamil and nifedipine, a cross-over, double-blind, randomised trial was carried out in 30 male out-patients with a history of stable exertional angina, proven coronary disease and a positive stress test (ST-segment depression > or = 1 mm). After a first 1-week wash-out period on placebo, the patients were randomised to gallopamil, 150 mg/day (50, 50 and 50) or nifedipine, 30 mg/day (10, 10 and 10) for 28 days. After a second 1-week wash-out period active treatments were crossed for another 28 days. At the end of each drug or placebo period, a physical examination, laboratory tests and a stress test were performed. Oral short-acting nitrates were permitted throughout the trial periods. Twenty-one patients finished all periods of the study. Both drugs reduced the maximum ST-segment depression during the exercise test: from 2.45 +/- 0.97 mm (placebo) to 1.95 +/- 0.82 mm (gallopamil, P < 0.05) and from 2.50 +/- 0.93 mm (placebo) to 1.75 +/- 0.84 mm (nifedipine, P < 0.05). Gallopamil but not nifedipine increased stress tolerance significantly: from 486 +/- 156 s (placebo) to 598 +/- 138 s (gallopamil, P < 0.05) and from 509 +/- 113 s (placebo) to 567 +/- 191 s (nifedipine, NS). No significant differences were found between drugs. Both calcium antagonists, gallopamil and nifedipine, showed similar efficacy in treating myocardial ischemia.

[Clinical and angiographic expression of myocardial ischemia in stable angina as a function of its coronary reserve]. / Expresión clínica y angiográfica de la isquemia miocárdica en la angina estable en función de su reserva coronaria.

We have studied the distribution of the coronary reserve, evaluated by serial effort tests, in patients with proved coronaropathy, determining the correlation between clinic (effort and mixed angina) and coronary reserve (fixed and variable), assessing angiographic findings in function to that reserve. We took 120 patients with stable angina to whom 2 effort tests were performed, basal and after vasodilator drugs. It was considered variable reserve if in the second test the S-T descend improved greater than or equal to 1 mm for a similar of greater double product and fixed when it didn't improve. In all patients coronarography was performed. Seventy two patients (60%) showed fixed reserve, 58 with effort angina (80%) and 14 (20%) with mixed. Forty eight showed variable reserve, 40 (80%) with mixed angina and 8 (17%) with effort. The group with fixed reserve had a greater S-T max. descent (2.9 +/- 0.9 vs 2.2 +/- 0.4) (p less than 0.001), a lower double product max. (221 +/- 44 vs 284 +/- 37) (p less than 0.001) and a lower maximal oxygen consumption (MVO2 7 +/- 2 vs 11 +/- 2) (p less than 0.001) than the variable reserve group. Considering the angiography, the fixed reserve group had more number of vessels affected (1.9 +/- 0.7 vs 1.4 +/- 0.5) (p less than 0.01), a higher angiographic score (4.88 +/- 2.4 vs 2.2 +/- 1.2) (p less than 0.001), a lower ejection fraction (59 +/- 8.5 vs 65 +/- 7.5) (p less than 0.001), more multivessel and descending anterior artery lesion than the variable reserve group.(ABSTRACT TRUNCATED AT 250 WORDS)