This article presents the devising, development, prototyping and assessment of a wearable arm-ECG sensor system (WAMECG1) for long-term non-invasive heart rhythm monitoring, and functionalities for acquiring, storing, visualizing and transmitting high-quality far-field electrocardiographic signals. The system integrates the main building blocks present in a typical ECG monitoring device such as the skin surface electrodes, front-end amplifiers, analog and digital signal conditioning filters, flash memory and wireless communication capability. These are integrated into a comfortable, easy to wear, and ergonomically designed arm-band ECG sensor system which can acquire a bipolar ECG signal from the upper arm of the user over a period of 72 h. The small-amplitude bipolar arm-ECG signal is sensed by a reusable, long-lasting, Ag–AgCl based dry electrode pair, then digitized using a programmable sampling rate in the range of 125 to 500 Hz and transmitted via Wi-Fi. The prototype comparative performance assessment results showed a cross-correlation value of 99.7% and an error of less than 0.75% when compared to a reference high-resolution medical-grade ECG system. Also, the quality of the recorded far-field bipolar arm-ECG signal was validated in a pilot trial with volunteer subjects from within the research team, by wearing the prototype device while: (a) resting in a chair; and (b) doing minor physical activities. The R-peak detection average sensibilities were 99.66% and 94.64%, while the positive predictive values achieved 99.1% and 92.68%, respectively. Without using any additional algorithm for signal enhancement, the average signal-to-noise ratio (SNR) values were 21.71 and 18.25 for physical activity conditions (a) and (b) respectively. Therefore, the performance assessment results suggest that the wearable arm-band prototype device is a suitable, self-contained, unobtrusive platform for comfortable cardiac electrical activity and heart rhythm logging and monitoring.

Bipolar ECG signals obtained from sensors in a band on the left upper-arm after signal processing can provide recordings of sufficient quality for long-term ECG monitoring. We present an cable-free, wearable sensor system (WAMECG1) for bipolar arm-ECG recording and wireless data transmission over a Wi-Fi link. The system's functional blocks were integrated into an ergonomically designed armband ECG device. A retrospective pilot analysis of the WASTCArD arm-ECG mapping database from our previous work, was perforned to obtain the optimal axis rotation of the bipolar electrodes pair with respect to the frontal ECG plane and the arm axilla point. The optimal signal was found to be at-30 o axis rotation. Then, signal quality of the recorded farfield bipolar arm-ECG was validated in a pilot trial with 10 volunteer subjects at rest using the prototype device. The overall R peak detection accuracy was 99.67%. Without using any signal enhancement algorithm, the average signal-to-noise-ratio (SNR) values was 16.73. These performance assessment results validated the performance of the wearable armband prototype device.

La diatomita está presente en la industria minera especialmente en el proceso de Merril Crowe en la clarificación de la solución Pregnant y en los filtros de prensas los cuales permiten cosechar el precipitado de oro para su posterior fundición. La siguiente investigación se basó en la diatomita y su capacidad de adsorción de oro en la clarificación de solución Pregnant. Se realizaron ensayos físico-químicos iniciales para la solución Pregnant (pH, turbidez, medición de la fuerza del cianuro y de metales como cobre, oro y plata). Para realizar las pruebas de la diatomita, ésta fue lavada, secada y tamizada en malla N° 200. La muestra se sinterizó (activación térmica) a 700 °C y se pulverizó. La pulpa proveniente de planta, fue filtrada para obtener la solución con la cual se realizaron las pruebas: agitación a 50 y 60 rpm durante 6 a 8 horas y un pH entre 10 y 11. Se procedió a sedimentar la muestra para después obtener el sólido (diatomita), el cual fue secado para su posterior fundición y recuperación del mineral precioso adsorbido. Los resultados mostraron una disminución de la concentración inicial de un 23% en oro. Dichos resultados nos ayudaron a analizar que la velocidad de agitación de la clarificación debe ser mínima para evitar la pérdida de oro en la solución Pregnant. Se hizo un análisis con microscopía electrónica de barrido de la diatomita activada antes y después de la adsorción, mostrándose la diferencia de su morfología

Resumen-El objetivo principal de este trabajo es diseñar e implementar un software libre para leer historias clínicas electrónicas basadas en el estándar Health Level 7 / Clinical Document Architecture (HL7/CDA). La implementación del software fue realizada utilizando la metodología Programación Extrema, PHP, Javascript y XML asíncronos (AJAX) y las herramientas Apache 2 y Eclipse 3.1. El lector recibe un documento XML codificado en HL7/CDA y luego organiza su contenido en la memoria del computador. Las pruebas fueron realizadas en Linux Ubuntu 6.06 LTS y Windows XP SP2, utilizando Apache 2 y PHP 5. Los resultados obtenidos muestran que es posible la recepción de historias clínicas electrónicas que se encuentren en conformidad con el estándar HL7/CDA. Se concluye que el lector facilita la gestión de la información contenida en historias clínicas codificadas en HL7/CDA luego de su recepción, representando así una contribución al intercambio de información clínica para servicios de telemedicina.

The goal of this research was to develop a digital system that could allow managing electronic medical records (EMRs) codified under specifications of the Health Level 7/Clinical Document Architecture (HL7/CDA) international standard, and saving them in a portable digital storage device called iButton ®. To this end, an USB-based hardware interface for reading and storing EMRs in iButtons was designed and implemented. In addition, a software application for invoking read/ write operations on stored EMRs and showing their content on a graphical user interface was also developed, following the Extreme Programming (XP) software development methodology and using Visual Basic .NET as programming language. Tests conducted on the hardware interface showed that it was able to recognize any iButton type, reading and writing data on them as well. Moreover, the system helped in creating empty EMRs in conformance with the HL7/CDA standard, adding and viewing information, and updating it in the iButton. This system offers an easy way for managing and visualizing medical records codified in HL7/CDA, and allows patients to take their updated medical history with them everywhere.