Browsing by Author "Mercado-Aguirre I.M."

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A wearable system for biosignal monitoring in weightlifting
(Springer London, 2017) Mercado-Aguirre I.M.; Mercado-Medina E.L.; Chavarro-Hernandez Z.D.; Domínguez Jiménez, Juan Antonio; Contreras Ortiz, Sonia Helena
The use of technological aids in sports has increased in the last years. These tools allow to register the athletes’ movements to evaluate and track their performance over time. With that information, it is possible to design more effective training routines, prevent and treat injuries, and improve performance. This paper describes the design and construction of an electronic system to register joint angle and electromyography signals during the execution of weightlifting exercises. The system was designed to be unobtrusive, energy efficient, and low cost. It was evaluated during the execution of flexion/extension exercises of the arm with weights, and was effective to acquire the signals and transmit them wirelessly in real-time. Electromiography signals were visualized and analyzed with an adequate dynamic range, and angle measurements were performed with error percentages less than 0.8 %. © 2016, International Sports Engineering Association.
Acquisition and Analysis of Cognitive Evoked Potentials using an Emotiv Headset for ADHD Evaluation in Children
(Institute of Electrical and Electronics Engineers Inc., 2019) Mercado-Aguirre I.M.; Gutiérrez-Ruíz, Karol; Contreras Ortiz, Sonia Helena
Attention-deficit/hyperactivity disorder (ADHD) is a neurological condition that affects the quality of life of the patients. It can be diagnosed using a combination of psychological tests. In addition to that, the brain activity of the patients can be analyzed using electroencephalography (EEG). The application of EEG tests requires the cooperation of the patients, which can be challenging in patients with ADHD. This paper describes the development of a system for stimuli generation, and acquisition and analysis of cognitive evoked potentials using the commercial system Emotiv EPOC+ headset. The results show that the system allows precise and reliable measurements of the P300 waves in children, and may provide a more comfortable experience for the patients compared to medical-grade systems. © 2019 IEEE.
Design and construction of a wearable wireless electrogoniometer for joint angle measurements in sports
(Springer Verlag, 2017) Mercado-Aguirre I.M.; Contreras Ortiz, Sonia Helena; Bustamante J.; Sierra D.A.; Torres I.
Advances in the field of biomedical engineering have allowed the development of biometric devices to evaluate sport performance. This article describes the design and construction of a wearable electrogoniometer to monitor joint angle in real time for sports applications. The electrogoniometer uses four accelerometers connected to a microcontroller. The joint angle is estimated and transmitted via Bluetooth Low Energy. This prototype is a low-cost, low-power, and comfortable to wear solution for joint angle measurement. © Springer Nature Singapore Pte Ltd. 2017.
Region growing segmentation of ultrasound images using gradients and local statistics
(SPIE, 2017) Mercado-Aguirre I.M.; Patiño Vanegas, Alberto; Contreras Ortiz, Sonia Helena; Duric N.; Heyde B.
This paper describes a region growing segmentation algorithm for medical ultrasound images. The algorithm starts with anisotropic diffusion filtering to reduce speckle noise without blurring the edges. Then, region growing is performed starting from a seed point, using a merging criterion that compares intensity gradients to the noise level inside the region. Finally, the boundaries are smoothed using morphological closing. The algorithm was evaluated with two simulated images and eleven phantom images and converged in 10 of them with accurate region delimitation. Preliminary results show that the proposed method can be used for ultrasound image segmentation and does not require previous knowledge of the anatomy of the structures. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.