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Manual assembly operations are sensitive to human errors that can diminish the quality of final products. The paper shows an application of human reliability analysis in a realistic manufacturing context to identify where and why manual assembly errors occur. The techniques SHERPA and HEART were used to perform the analysis of human reliability. Three critical tasks were selected for analysis based on quality records: (1) installation of three types of brackets using fasteners, (2) fixation of a data cable to the assembly structure using cushioned loop clamps and (3) installation of cap covers to protect inlets. The identified error modes with SHERPA were: 36 action errors, nine selection errors, eight information retrieval errors and six checking errors. According to HEART, the highest human error probabilities were associated with assembly parts sensitive to geometry-related errors (brackets and cushioned loop clamps). The study showed that perceptually engaging assembly instructions seem to offer the highest potential for error reduction and performance improvement. Other identified areas of action were the improvement of the inspection process and workers’ provision with better tracking and better feedback. Implementation of assembly guidance systems could potentially benefit worker’s performance and decrease assembly errors.

Despite the increasing level of automation and digitalization in manufacturing, manual assembly is still important. Factors affecting human performance can increase errors and generate quality issues. In this paper, we investigate how overtime allocation practices can impact the level of fa-tigue. The manufacturing process object of analysis face variations in pro-duction levels and staffing needs change accordingly. A total of 12 shift ar-rangements (six mornings and six evenings) were evaluated using the Fa-tigue Index developed by the Health and Safety Executive (HSE) in the United Kingdom. Results show that evening shifts are in general more sen-sitive to overtime allocation compared to morning shifts due to the difference in lengths and time of the day. The analysis helps supervisors to take into account the different impacts of overtime allocation practices on potential levels of fatigue depending on the type of shift and the shift arrangement.

Manual assembly operations are sensitive to human errors that can diminish the quality of final products. The paper shows an application of human reliability analysis in a realistic manufacturing context to identify where and why manual assembly errors occur. The techniques SHERPA and HEART were used to perform the analysis of human reliability. Three critical tasks were selected for analysis based on quality records: (1) installation of three types of brackets using fasteners, (2) fixation of a data cable to the assembly structure using cushioned loop clamps and (3) installation of cap covers to protect inlets. The identified error modes with SHERPA were: 36 action errors, nine selection errors, eight information retrieval errors and six checking errors. According to HEART, the highest human error probabilities were associated with assembly parts sensitive to geometry-related errors (brackets and cushioned loop clamps). The study showed that perceptually engaging assembly instructions seem to offer the highest potential for error reduction and performance improvement. Other identified areas of action were the improvement of the inspection process and workers’ provision with better tracking and better feedback. Implementation of assembly guidance systems could potentially benefit worker’s performance and decrease assembly errors.

Introduction: Cardiovascular rehabilitation is beneficial in multiple clinical situations. In patients who are treated through percutaneous coronary intervention it is necessary to continue deepening its study.Objectives: To determine the effects of cardiovascular rehabilitation in patients with ST-segment elevation acute myocardial infarction who underwent percutaneous coronary intervention.Method: Quasi-experimental study in 30 patients with ST-segment elevation acute myocardial infarction after being treated with coronary angioplasty, and who were attended at the Department of Cardiovascular Rehabilitation of the Hospital Universitario Celestino Hernández Robau, in the period from September 2016 to March 2018. Clinical and epidemiological data were collected, and ergometric and echocardiographic variables were analyzed before and after 12 weeks of developing a cardiovascular rehabilitation program.Results: There was a positive effect on heart rate at rest (66±11 vs. 61±11 beats/minute; p=0.008), exercise time (8.3±2.5 vs. 10.2±2.0 minutes; p<0.0001) and maximum oxygen consumption (24.2±5.0 vs. 27.6±4.9 ml/kg/min; p<0.0001). There was improvement of the ejection fraction and reduction of the diameter of the left ventricle in diastole left ventricular end diastolic diameter, but without significant statistical difference.Conclusions: There was improvement in the ergometric and echocardiographic parameters after the cardiovascular rehabilitation program, which was more beneficial in patients with high blood pressure, smoking habit and percutaneous coronary intervention of two arteries., Introducción: La rehabilitación cardiovascular es beneficiosa en múltiples situaciones clínicas. En pacientes que son tratados mediante intervencionismo coronario es necesario seguir profundizando su estudio.Objetivo: Determinar los efectos de la rehabilitación cardiovascular en pacientes con infarto agudo de miocardio con elevación del segmento ST a quienes se les realizó intervencionismo coronario percutáneo.Método: Estudio cuasi-experimental en 30 pacientes con infarto agudo de miocardio con elevación del ST después de ser tratados con angioplastia coronaria y que se atendieron en el Servicio de Rehabilitación Cardiovascular del Hospital Universitario Celestino Hernández Robau, en el período de septiembre de 2016 a marzo de 2018. Se recolectaron datos clínicos y epidemiológicos, y se analizaron variables ergométricas y ecocardiográficas al inicio y luego de 12 semanas de realizar un programa de rehabilitación cardiovascular.Resultados: Existió un efecto positivo en la frecuencia cardíaca en reposo (66±11 vs. 61±11 latidos/minuto; p=0,008), el tiempo de ejercicio (8,3±2,5 vs. 10,2±2,0 minutos; p<0,0001) y del máximo consumo de oxígeno (24,2±5,0 vs. 27,6±4,9 ml/kg/min; p<0,0001). Existió mejoría de la fracción de eyección y reducción del diámetro del ventrículo izquierdo en diástole, pero sin diferencia estadística significativa.Conclusiones: Existió mejoría en los parámetros ergométricos y ecocardiográficos luego del programa de rehabilitación cardiovascular, que fue más beneficioso en pacientes con hipertensión arterial, hábito de fumar e intervencionismo coronario percutáneo de dos arterias.

The appearance of J waves is the most common event observed in the electrocardio-gram of a patient with hypothermia. We report the case of 47 years-old man, who underwent cardiac arrest using hypothermia for cardiac surgery. In the electrocardio-graphic tracing the progressive development of giant J waves is evident. These waves can mimic acute myocardial infarction and are considered a predictor of arrhythmo-genesis., La aparición de ondas J es el suceso más común observado en el electrocardiograma de un paciente con hipotermia. Se presenta el caso de un hombre de 47 años, que le fue inducido un paro cardíaco mediante hipotermia para una cirugía cardíaca. En el trazo electrocardiográfico se evidencia el desarrollo progresivo de una onda J exu-berante. Estas ondas pueden simular un infarto agudo de miocardio y se consideran una variable predictora de arritmogénesis.

Introduction y Objetive: P wave dispersion and its maximum duration have been linked with increased risk for developing atrial fibrillation. These variables have been little studied in elite athletes. Our objective was to characterize the P wave dispersion and its maximum duration in high performance soccer players, and correlate them with other variables. Method: Cross-sectional study conducted at the end of the preparation period (December 2010), prior to the national championship. 24 athletes of the provincial soccer team of Villa Clara, Cuba were studied. Electrocardiographic variables were measured with manual digital caliper. Results: Mean age of athletes was 24.04 ± 4.72 years and the average sport practice time was 13.38 years. The athletes studied showed higher values of maximum P wave duration (111.57 ms vs. 96.0 ms, P <0.001) and P wave dispersion (49.26 ms vs. 38.0 ms, P = 0.006). There was a positive and significant correlation between the dispersion of such wave and sport practice time (r = 0.52, p = 0.009). Conclusions: P wave dispersion and its maximum duration are increased in the soccer players studied, so there is a positive linear correlation between the former and sport practice time., Introducción y Objetivo: La dispersión de la onda P y su máxima duración se han vinculado con el riesgo incrementado para desarrollar fibrilación auricular. Estas variables han sido escasamente estudiadas en deportistas de elite. El objetivo fue caracterizar la dispersión de la onda P y su máxima duración en futbolistas de alto rendimiento, y correlacionarlas con otras variables. Método: Estudio de corte transversal realizado al final de la etapa de preparación (diciembre 2010), previo al campeonato nacional. Se estudiaron 24 atletas del equipo provincial de fútbol de Villa Clara, Cuba. Las variables electrocardiográficas fueron medidas con cáliper digital manual. Resultados: La media de edad de los atletas fue de 24,04 ± 4,72 años y el tiempo promedio de práctica deportiva, 13,38 años. Los atletas estudiados mostraron valores más elevados de máxima duración de la P (111,57 ms vs. 96,0 ms; p < 0.001) y de dispersión de la onda P (49,26 ms vs. 38,0 ms; p= 0.006). Existió una correlación positiva y significativa entre la dispersión de dicha onda y el tiempo de práctica deportiva (r=0,52; p=0.009). Conclusiones: La dispersión de la onda P y su máxima duración están incrementadas en los futbolistas estudiados, por lo que existe una correlación positiva y lineal entre la primera y el tiempo de práctica deportiva.

Heart rate turbulence: a useful parameter in predicting sudden cardiac death, Turbulencia de la frecuencia cardíaca: un parámetro útil en la predicción de muerte súbita cardíaca