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.

Textural, physicochemical and sensory properties compensation of fat replacing in pork liver pâté incorporating emulsified canola oil.

Saturated animal fat was replaced in pork pâté with pre-emulsified canola in a 3% sodium caseinate/0.5% xanthan gum solution in order to obtain a stable oily phase. Fat was replaced with different proportions of emulsified canola oil. The inclusion of emulsified oil in pâté enhanced cocking yield and moisture but increased fluids release. Nonetheless, total fat content remained practically constant, meaning no detrimental effect on caloric content. Replacing 50% of lard with emulsified oil did not affect color of the samples. Texture was improved since emulsified oil addition resulted in softer and more spreadable pâté. Samples with 50% of emulsified oil were more stable to lipid oxidation at 8 days of storage, with lower thiobarbituric acid-reactive substances and volatile compounds resulting from oxidation reactions. Emulsified canola can be employed to replace fat until 50% in pâté or liver sausage with good functional properties, improving texture and reducing lipids rancidity.

Prevalence of malnutrition in Mexican CAPD diabetic and nondiabetic patients.

Malnutrition is often present on continuous ambulatory peritoneal dialysis (CAPD), and contributes to morbidity and mortality. Diabetics (DM) have an increased risk for developing malnutrition. Our purpose was to assess the nutritional status (NS) of our CAPD population, to define NS differences between DM and nondiabetics (NoDM), and to identify NS-related factors. Patients were subjected to a nutritional assessment, which included a 24-hour dietary recall and a nutritional scoring system including anthropometric, biochemical, and subjective evaluation, and that classifies patients as: normal, and mildly, moderately, and severely malnourished. We studied 90 patients: 35 DM and 55 NoDM. In our whole population we observed a high frequency of malnutrition: NS was normal in 18%, and 20% had mild, 24% had moderate, and 38% had severe malnutrition. Ninety-one percent of DM and 76% of NoDM showed some degree of malnutrition. DM patients had significantly higher levels of malnutrition (p = 0.02), were significantly older, had more body fat, and spent less time on dialysis. There were 37 males and 53 females. Sex distribution was similar between DM and NoDM. Seventy-six percent of males and 86% of females had malnutrition. Moderate and severe malnourishment were more frequent in females. DM and female sex were the strongest predictors for moderate and severe malnutrition.

[Validity of death certificates for cancer in Mallorca]. / Validez de los certificados de defunción por cáncer en Mallorca.

We assessed the quality and completeness of the information of death certificates (CMD) for cancer in Mallorca during 1989. Likewise we studied the possible bias introduced by the excluded cases for lack of clinical information (DCO cases). We compared the information of the death certificates with the clinical records and data of the Population-based Cancer Registry. A global concordance of 77.2% was obtained out of 1,173 certificates. This concordance varied according to sex (males: 79.8%, women: 73.1%; p < 0.01), place of death (hospital: 83.1%, home: 69.6%; p < 0.001) and age ( < 50 years: 77.8%; > 70 years: 74.2%; p < 0.05). The best notified sites were: breast, lung, and leukemias and the worst, unknown and poorly defined sites, bones and soft tissue tumours. We detected that the death certificates carry a subnotification of at least 5% in cancer deaths. Even so, they result a valid source of information for the Population-based Cancer Registry. The cases excluded for lack of clinical documentation present a more advanced age and a greater proportion of hepatic cancers and unknown and poorly defined sites.

[Registration with piezoelectric sensors of the in vivo activity of right ventricular contractile elements in acute experimental pulmonary stenosis]. / Registro con sensores piezoeléctricos de la actividad "in vivo" del elemento contráctil del ventrículo derecho en estenosis pulmonares experimentales agudas.

Recordings with piezoelectric sensors of the variations of the contractile state due to severe acute pulmonary hypertension, provoked in intact canine hearts, are described. During the stenosis, a proportional increment of the isometric tension of the right ventricular wall and of the right atrial kick, due to the increasing difficulties for the respective blood contents evacuation of both cavities, were appreciated. Furthermore, lost of the right wall compliance, becoming more rigid, limited the systolic and diastolic pressure development of the right ventricle. Meanwhile, the piezoelectric sensor sutured on the left ventricular wall describes the consequent variations of the left ventricular contraction.

Registro con sensores piezoeléctricos de la actividad [quot ]in vivo[quot ] del elemento contráctil del ventrículo derecho en estenosis pulmonares experimentales agudas. / [Registration with piezoelectric sensors of the in vivo activity of right ventricular contractile elements in acute experimental pulmonary stenosis]

Recordings with piezoelectric sensors of the variations of the contractile state due to severe acute pulmonary hypertension, provoked in intact canine hearts, are described. During the stenosis, a proportional increment of the isometric tension of the right ventricular wall and of the right atrial kick, due to the increasing difficulties for the respective blood contents evacuation of both cavities, were appreciated. Furthermore, lost of the right wall compliance, becoming more rigid, limited the systolic and diastolic pressure development of the right ventricle. Meanwhile, the piezoelectric sensor sutured on the left ventricular wall describes the consequent variations of the left ventricular contraction.

[Recording, with piezoelectric sensors, of the activity of the contractile elements in vivo in experimental acute and chronic aortic stenosis]. / Registro con sensores piezoeléctricos de la actividad del elemento contráctil "in vivo" en estenosis aórticas experimentales agudas y crónicas.

Mechanic alterations of the left ventricular wall due to an increasing afterload by means of experimentally provoked acute and chronic aortic stenosis, registered by piezoelectric sensors sutured on the surface of the ventricle, are analyzed. Tension or force developed in the ventricular wall or the acceleration of the shortening velocity of the contractile element, under these conditions, show in the piezoelectric sensor curve a new characteristic contractile state depending on the rapidity and time elapsed since the aortic stenosis, making clear the diagnosis, systolic peaks and their evolutionary stage. Different adaptation mechanisms employed by the myocardium, according to the rapidity of the experimental stenosis, showed by means of the variations of the different phases of the cardiac cycle depicted by sensor curves, are also described.

Registro con sensores piezoeléctricos de la actividad del elemento contráctil [quot ]in vivo[quot ] en estenosis aórticas experimentales agudas y crónicas. / [Recording, with piezoelectric sensors, of the activity of the contractile elements in vivo in experimental acute and chronic aortic stenosis]

Mechanic alterations of the left ventricular wall due to an increasing afterload by means of experimentally provoked acute and chronic aortic stenosis, registered by piezoelectric sensors sutured on the surface of the ventricle, are analyzed. Tension or force developed in the ventricular wall or the acceleration of the shortening velocity of the contractile element, under these conditions, show in the piezoelectric sensor curve a new characteristic contractile state depending on the rapidity and time elapsed since the aortic stenosis, making clear the diagnosis, systolic peaks and their evolutionary stage. Different adaptation mechanisms employed by the myocardium, according to the rapidity of the experimental stenosis, showed by means of the variations of the different phases of the cardiac cycle depicted by sensor curves, are also described.

[Registration with piezoelectric sensors of the normal in vivo activity of the contractile element of the right ventricle]. / Registro con sensores piezoeléctricos de la actividad normal "in vivo" del elemento contráctil del ventrículo derecho.

A new method employed for registration with piezoelectric sensors of the force developed or acceleration of shortening velocity of the contractile element, throughout the right cardiac cycle, is described. The normal activity of the contractile element shows different aspects in both ventricles. SPz curve of the right ventricle is compared with the correspondent SPz curve of the left ventricle. The former curve shows that blood ejection to pulmonary artery is essentially due to developed force or acceleration of shortening velocity of the contractile element, during the isometric contraction phase of the cardiac cycle. Ejection period, with quite constant shortening velocity, seems to complete the blood expulsion. Left ventricular blood flow to systemic circuit is mainly due to early ejection phase, where developed force or acceleration of the shortening velocity of the contractile element appears to be higher, to impulse blood to the aortic artery.

Registro con sensores piezoeléctricos de la actividad normal [quot ]in vivo[quot ] del elemento contráctil del ventrículo derecho. / [Registration with piezoelectric sensors of the normal in vivo activity of the contractile element of the right ventricle]

A new method employed for registration with piezoelectric sensors of the force developed or acceleration of shortening velocity of the contractile element, throughout the right cardiac cycle, is described. The normal activity of the contractile element shows different aspects in both ventricles. SPz curve of the right ventricle is compared with the correspondent SPz curve of the left ventricle. The former curve shows that blood ejection to pulmonary artery is essentially due to developed force or acceleration of shortening velocity of the contractile element, during the isometric contraction phase of the cardiac cycle. Ejection period, with quite constant shortening velocity, seems to complete the blood expulsion. Left ventricular blood flow to systemic circuit is mainly due to early ejection phase, where developed force or acceleration of the shortening velocity of the contractile element appears to be higher, to impulse blood to the aortic artery.