Examinando por Autor "Valencia Murillo, José Fernando"
Mostrando 1 - 9 de 9
Resultados por página
Opciones de clasificación
- PublicaciónAcceso abiertoDiseño de prototipo electrónico para la adquisición multicanal de señales de electroencefalograma(2016-11-24) Peña Carrera, Cristian David; Moreno Camacho, Ricardo; Valencia Murillo, José FernandoThis document presents the implementation, results and conclusions of the degree project called "Electronic design prototype multichannel electroencephalogram signal acquisition". It uses the ADS1299 specific application integrated circuit that allows the capture of eight differential channels and the Rapsberry Pi development board as the implemented system processor. The SPI communication protocol is used to perform bidirectional data transfer between the ADS1299 and the Raspberry Pi, and the necessary isolations are implemented in accordance with the IEC 60101-1 standard, which describes the general requirements that the Electromedical systems for patient safety purposes. The appropriate system identification, hardware design and software implementation are shown and the implementation of LEAD-OFF (electrode disconnection) detection and impedance measurement in the electrode connection in the patient is taken into account.
- PublicaciónAcceso abiertoImplementación de la transformada wavelet sobre un sistema embebido para el pre-procesamiento de señales unidimensionales no estacionarias(2016-11-29) Ruiz Salazar, Jeferson; Orejuela Caicedo, David Alexander; Valencia Murillo, José Fernando; Valencia Vargas, Daniel FelipeSeveral methods are used for signal processing, one of them is the Wavelet Transform (WT) algorithm. The WT is employed in the field of signal denoising; it has proved to be a tool that fits effectiveness in terms of execution time and precision. In this project, WT implementation on FPGA is proposed for denoising one-dimensional non-stationary signals. WT has been represented by the lifting method using four decomposition levels. To verify the design four EEG signals sampled at 100Hz collected from BCI competition III, corrupted by white Gaussian noise 20dB of SNR were used. The results were analyzed by two numerical evaluation criteria, such as Peak signal-to-noise ratio (PSNR) and mean square error (RMSE), which showed an improvement of 1.9 regarding RMSE and 1.7 concerning PSNR about the noisy signal.
- PublicaciónAcceso abiertoImplementación de una interfaz cerebro-computador (BCI) que permita controlar el movimiento de elevación y avance durante el vuelo de un cuadricóptero (dron)(Universidad de San Buenaventura - Cali, 2017) Castro Gutiérrez, Andrés Felipe; Ortega Hernández, Juan Felipe; Valencia Murillo, José FernandoIn this project, a brain-computer interface (BCI) is implemented allowing flight control of a simulated drone through the use of steady state visual evoked potentials (SSVEP) that were generated by a light dashboard that could be adjusted to blink at different frequencies. Through a sweep of frequencies made between 20 and 40 Hz, five different frequencies can be identified: 22, 25, 26, 27 and 34 Hz, which were assigned to the same number of movements: ascent, descent, advance, rewind and rotate clockwise, respectively. The project makes use of a Matlab script that is responsible for the reception and processing of the EEG data, identifying the stimulus selected by the user, calculating which of the five frequencies has the highest energy during a control period of two seconds. The interface was validated by applying five pattern tests to six users, each test had the duration of one minute, the efficiency found was between 72.18% and 95.33%.
- PublicaciónAcceso abiertoImplementación sobre una FPGA de un modelo farmacocinético y farmacodinámico (PK/PD) para aplicación en anestesia general(Universidad de San Buenaventura - Cali, 2018) Cardona García, Maria Camila; Vallejo Santacruz, David Alejandro; Valencia Vargas, Daniel Felipe; Valencia Murillo, José FernandoIn the application of general anesthesia, the implementation of pharmacokinetic /pharmacodynamics models (PK / PD) are a very useful tool for making decisions and analysis. These models allow to know the behavior over time of the drug and its effect on the human body, either in an instant or in a predictive way. In this research work the implementation of the model PK / PD of Minto for Remifentanil on an FPGA was carried out for its attractive features in medical devices such as reprogrammability, safety, greater reliability and control of the data and execution times, fast processing, scalability, because they are described in hardware. For the solution of the Minto’s PK/PD model, the numerical method fourth order Runge-Kutta was chosen. A preliminary design was made in MATLAB and compared with the ode45 of the same platform to verify the validity of the algorithm. The hardware description was made in the Quartus software in VHDL and it was implemented on an Altera DE0- Nano kit. The tests were made using Simulink's FPGA-in-the-loop strategy. The results showed that it is possible to implement this type of models on FPGAs without using special functions, with a minimum error, almost negligible between the result delivered by MATLAB and the one obtained in the implementation on the Altera.
- PublicaciónAcceso abiertoInterfaz gráfica para análisis de señales del electroencefalograma(2015-11-23) Quijano Lopez, Andres Felipe; Valencia Murillo, José FernandoUsing a graphical interface that displays EEG signals depend more on the user's opinion that complex processing algorithms. In this paper the most important features are presented in a graphical interface that works with EEG signals in order to define specifications that allow an interface to a usable computer application. The characteristics of a GUI initially drawn from a process of searching, comparing and ranking different medical and work done with software EEG signals. Then the universal characteristics will be established and existing evidence to evaluate graphical user interfaces will be studied. Subsequently, a survey was applied in order to obtain a user's needs. The results indicate the importance of the user in the design process of user interfaces. The type of investigation is applied research
- PublicaciónAcceso abiertoSistema electrónico de alarma y control de incendio para cubiertas de material orgánico seco(Universidad de San Buenaventura - Cali, 2017) Jiménez Caro, Andrés Felipe; Jaramillo Arias, José Luis; Valencia Murillo, José FernandoThis project proposes a solution to counteract fires in decks made of dry organic material, replacing smoke, temperature and flame sensors with a video camera solution. For this purpose a scale model of a structure covered by dry organic material was implemented, where the presence of a fire is detected that is captured by a camera and analyzed by an engineering station. As an engineering station there is a Raspberry Pi 3, which evaluates a series of rules based on the RGB and YCbCr color components of the images captured by the camera for the classification of fire pixels; Subsequently, control actions are executed according to design criteria. To control the fire, there is an electrovalve that is operated by a control signal emitted from the engineering station, giving way to the water flow through a pipe that finally irrigates the cover by means of a sprinkler. The device's response to real fire situations is evaluated through a series of tests that help determine just how accurate, precise, and sensitive it is overall. The designed device has a percentage of 98% of fire detection and 12% of false alarms, fulfilling satisfactorily with the desired operation, since it detects, notifies and controls the presence of a fire that is present in a cover of dry organic material, Thus minimizing the losses that may occur in the event of catastrophe, where the main author is the fire.
- PublicaciónAcceso abiertoSistema electrónico para reproducir señales biomédicas pregrabadas en una base de datos(Universidad de San Buenaventura - Cali, 2017) Santacruz Mesías, José Andrés; Valencia Murillo, José Fernando; Valencia Vargas, Daniel FelipeBioelectrical signals, such as the electroencephalogram (EEG), are useful in operating rooms. It is helpful to reproduce (accurately) by the embedded systems in the operating rooms. The aim of this project is to develop is an embedded system for the reproduction of bioelectrical signals, specifically focusing on the reproduction of EEG signals. The first phase of the project is based on an investigative stage, in which information is obtained to define the appropriate design and construction criteria for the project. Consistent with this, we select amount of devices that could meet the design and construction criteria established in the previous stage. For this purpose, a low-noise analog-digital converter with SPI communication protocol is chosen. Also, a user interface is developed to select and reproduce the signals save in the embedded system. Finally, we design a stage of adequation of the signal. The embedded system is controlled by a microcontroller, ATmega 2560. The expected values for the analogdigital converter are verified using an experimental design, where the input data is changed, and the voltage at the output of the converter is measure, we obtain that the theoretical and experimental results match 99%.
- PublicaciónAcceso abiertoSistema embebido destinado a la detección y eliminación de artefactos en señales EEG para aplicaciones médicas(2015-11-23) Lozada Tenorio, Cesar Augusto; David Medina, Bolívar Daniel; Valencia Murillo, José FernandoThe purpose of this degree project is to compare and implement in an embedded system algorithms to detect and reduce artifacts present in EEG signals of single channel. For this purpose an investigation of existing algorithms to detect and reduce artifacts in the EEG signals was performed, the algorithms that could be applied to the database available were selected. These algorithms were simulated using two tools, Matlab and Python. Finally the algorithms are implemented in an embedded system and the results was validated.
- PublicaciónAcceso abiertoSistema portable para la adquisición y procesamiento de señales ECG, con aplicabilidad en dispositivos móviles(Universidad de San Buenaventura - Cali, 2017) Villafuerte Echeverri, Santiago; Torres Avila, Harby; Valencia Murillo, José FernandoThe acquisition of electrocardiogram (ECG) signals is vital for diagnosing cardiovascular diseases, as it can reveal the actual state and conditions of the heart in patients under study. Currently, the fast advance of the electronic engineering had allowed the development of applications on the biomedicine field, implementing devices that allow bioelectrical signal acquisition and processing, leading to a specific and punctual monitorization of several organs of the human body. This makes easier, faster and better the medical procedures, improving the patients’ conditions during the medical interventions. In this project, a design of a portable system for ECG signal acquisition and processing, with applicability in mobile devices, is proposed, which is characterized principally for being a portable device that is easy to implement, both in the patient’s residences, as well as health care centers. The first step to develop the prototype is to build the electronic board based on the ADS1298 application-specific integrated circuit, by Texas Instruments Company, designed principally for ECG signals that counts with eight channels for data acquisition and a SPI communication port. The board works with the PIC32MX795F512H by the Microchip Company as the main processor of the system, which also has a SPI port for data transference between the ADS1298 and the PIC. The device programming is done through the MPLAB interface programming environment (MPLAB IPE), using libraries that were especially designed for the main code of the proposed device. Finally, a graphical user interface made in MATLAB® was implemented to display the recorded signals. The performed tests to validate the correct functionality of the ECG device shows that the planned development system has been accomplished, both in hardware and software. The needed requirements have been implemented in accordance with international rules of biomedical equipment. Finally, a device that registers twelve leads of ECG (Lead I, Lead II, Lead III, aVF, aVR, aVL, V1, V2, V3, V4, V5 y V6) has been obtained with a sample frequency of 250SPS, which can be visualized and registered in MATLAB®.