Mexicali Institute of Technology

www.itmexicali.edu.mx
Mexicali, Mexico
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Mayorga P.,Mexicali Institute of Technology | Valdez J.,Mexicali Institute of Technology | Druzgalski C.,California State University, Long Beach | Zeljkovic V.,Lincoln University at Lincoln Park
Pan American Health Care Exchanges, PAHCE | Year: 2017

Thoracic auscultatory signs are commonly evaluated as a part of standard diagnostic procedures which might be focused on cardiac (HS) or pulmonary (LS) origin indicators depending on evaluator's aims. However, due similarities of these sounds spectral components and their extremely small intensity especially in the presence of common external noise, a separation of their origin components can be difficult even for an experienced practitioner. This is specially challenging if he/she is presented with prior recordings of these sounds as a part of related auscultatory patient's record review. Differences in periodicity of these cardiac and pulmonary origin sounds assist in qualitative characterization while combined with proposed methods may lead to improved quantitative characterization and origin depended separation of their characteristics. This proposed and verified technique emphasizes initial localization of the HS related components and their subsequent extraction. Though, an examination of both HS and LS components is conducted concurrently as a part of an overall thoracic sounds analysis. In particular, as experimentally optimized, in the case of HS components assessment the Hilbert Transform (HT) is used to detect extreme points; while, in the LS components evaluation Voice Activity Detection techniques (VAD) and the calculation of thresholds of some components of acoustic vectors MFCC, are useful to detect and localize the events of particular examiner's interest. Also the inspiratory and expiratory phases can be differentiated by means of the sixth component of Cepstral Coefficient of Mel Frequency (MFCC). In order to evaluate the efficiency of this technique, it was decided to apply Hidden Markov Models with Mixed Gaussian Models (HMM-GMM). The events extracted from manual and automatic detection were used to calculate HMMGMM models and perform classification. Overall, this approach allows easier detection of any anomalies and their possible origin in complex cardiopulmonary disorders. © 2017 IEEE.


Zeljkovic V.,Lincoln University at Lincoln Park | Tameze C.,Lincoln University at Lincoln Park | Druzgalski C.,California State University, Long Beach | Mayorga P.,Mexicali Institute of Technology
Canadian Conference on Electrical and Computer Engineering | Year: 2017

Chickenpox is caused by the varicella-zoster virus (a member of the herpes virus family), which can be spread through the air or by direct contact with an infected person. It produces an itchy, blistery rash that typically lasts about a week and is sometimes accompanied by a fever or other symptoms but primarily manifested by numerous blisters. A single attack of chickenpox almost always brings lifelong immunity against the disease. Safe and effective vaccination represents good protection against chickenpox. The developed algorithm for a quantifiable visual symptoms of varicella evaluation was applied for a comparative assessment of the degree of disease manifestations in two groups of patients. This process demonstrates the levels of vaccination effectiveness and can be applied having images taken under different clinical conditions. This effective technique can be extended to other dermatologic applications with similar visual symptoms. © 2017 IEEE.


Fernandez D.,Baolab Microsystems | Martinez-Alvarado L.,Mexicali Institute of Technology | Madrenas J.,Polytechnic University of Catalonia
IEEE Journal of Solid-State Circuits | Year: 2012

A field-programmable analog array (FPAA) using a standard-CMOS wide-dynamic-range translinear element (TE) is introduced. The FPAA configurable analog blocks (CABs) are based on a reconfigurable translinear cell (RTC), capable of implementing the basic circuit elements required by translinear and log-domain circuit design. The interfacing is provided by an I/O programmable cell, which allows for easier connectivity between the signal-processing core and the external circuitry. As a proof-of-concept, a 5 × 5 RTC FPAA testchip was implemented in 0.35-μm CMOS technology. A set of various circuit primitives, such as one- and four-quadrant multipliers, an Euclidean distance operator and a fourth-order log-domain filter, were mapped on the chip in order to demonstrate the versatility of the approach. FPAA bandwidth reaches 20 MHz with a power consumption of 30 μW/TE and precision errors below 3%. © 2011 IEEE.


Diaz-Ramirez A.,Mexicali Institute of Technology | Dominguez E.,Mexicali Institute of Technology | Martinez-Alvarado L.,Autonomous University of Baja California
International Symposium on Technology and Society, Proceedings | Year: 2016

Accidental falls are one of the main causes of deaths and severe injuries of people over 65 years old. For this reason, the development of fall detection systems for the elderly has been an important research topic. In this paper, a non-invasive fall detection system for older people, based on the use of a wireless sensor network (WSN), is proposed. It uses the acoustic signal sensed by a node of the WSN, as well as signal processing and pattern recognition techniques to detect a fall. The model uses a signal-processing algorithm based on the use of cross-correlation to measure the similarity between the sampled signal and a reference template signal, which represents a fall event. If these two signals are similar, then the Mel-frequency cepstral coefficients (MFCC) of the fall sound are extracted. Afterwards, the dynamic time warping (DTW) method is used for pattern recognition. The evaluation of the proposed system showed a very good detection rate. © 2015 IEEE.


Diaz-Ramirez A.,Mexicali Institute of Technology | Mejia-Alvarez P.,CINVESTAV | Leyva-Del-Foyo L.E.,Metropolitan Autonomous University
Journal of Applied Research and Technology | Year: 2013

Schedulability conditions are used in real-time systems to verify the fulfillment of the temporal constraints of task sets. In this paper, a performance analysis is conducted for the best-known real-time schedulability conditions that can be used in online admission control on uni-processor systems executing under the Rate-Monotonic scheduling policy. Since Liu and Layland introduced the Rate-Monotonic scheduling algorithm, many research studies have been conducted on the schedulability analysis of real-time periodic task sets. However, in most cases, the performance of the proposed schedulability conditions were compared only against the Liu and Layland test and not against the remaining schedulability tests. The goal of this paper is to provide guidelines for system designers in order to decide which schedulability condition provides better performance under different task characteristics. Extensive simulation experiments were conducted to evaluate the inexact schedulability conditions and compare their performance and computational complexity.


Mayorga P,Mexicali Institute of Technology
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2012

In this paper a novel Lung Sound Automatic Verification (LSAV) system and front-end Quantile based acoustic models to classify Lung Sounds (LS) are proposed. The utilization of Quantiles allowed an easier and objective assessment with smaller computational demand. Moreover, less-complex Gaussian Mixture Models (GMM) were computed than those previously reported. The LSAV system allowed us to reach practically negligible error in healthy (normal) LS verification. LASV system efficiency and the optimal GMM's were evaluated by using Equal Error Rate (EER) and Bayesian Information Criterion (BIC) techniques respectively. These approaches could provide a tool for broader medical evaluation which does not rely, as it is often the case, on a qualitative and subjective description of LS.


Mayorga P.,Mexicali Institute of Technology
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference | Year: 2010

The focus of this paper is to present a method utilizing lung sounds for a quantitative assessment of patient health as it relates to respiratory disorders. In order to accomplish this, applicable traditional techniques within the speech processing domain were utilized to evaluate lung sounds obtained with a digital stethoscope. Traditional methods utilized in the evaluation of asthma involve auscultation and spirometry, but utilization of more sensitive electronic stethoscopes, which are currently available, and application of quantitative signal analysis methods offer opportunities of improved diagnosis. In particular we propose an acoustic evaluation methodology based on the Gaussian Mixed Models (GMM) which should assist in broader analysis, identification, and diagnosis of asthma based on the frequency domain analysis of wheezing and crackles.


Mayorga P.,Mexicali Institute of Technology | Druzgalski C.,California State University, Long Beach | Gonzalez O.H.,Mexicali Institute of Technology | Lopez H.S.,Mexicali Institute of Technology
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS | Year: 2012

In this paper a novel Lung Sound Automatic Verification (LSAV) system and front-end Quantile based acoustic models to classify Lung Sounds (LS) are proposed. The utilization of Quantiles allowed an easier and objective assessment with smaller computational demand. Moreover, less-complex Gaussian Mixture Models (GMM) were computed than those previously reported. The LSAV system allowed us to reach practically negligible error in healthy (normal) LS verification. LASV system efficiency and the optimal GMM's were evaluated by using Equal Error Rate (EER) and Bayesian Information Criterion (BIC) techniques respectively. These approaches could provide a tool for broader medical evaluation which does not rely, as it is often the case, on a qualitative and subjective description of LS. © 2012 IEEE.


Diaz-Ramirez A.,Mexicali Institute of Technology | Murrieta F.N.,Mexicali Institute of Technology | Atempa J.A.,Mexicali Institute of Technology | Bonino F.A.,Mexicali Institute of Technology
Proceedings - IEEE International Conference on Distributed Computing in Sensor Systems, DCoSS 2013 | Year: 2013

As a consequence of the aging of the world population, society and governments must face major challenges regarding people's health. In recent years, researches have been interested in investigating how the technology can be used to improve the healthcare and assistance of patients with dementia, as the Alzheimer's disease. In this paper, we propose a non-intrusive pervasive model to assist patients with dementia, based on the use of a wireless sensor network. Using high availability and low cost binary sensors, the proposed model is able to determine in real-time the location of a patient, and to emit alerts if one leaves a safe place without supervision. © 2013 IEEE.


Mayorga P.,Mexicali Institute of Technology | Druzgalski C.,California State University, Long Beach | Gonzalez O.H.,Mexicali Institute of Technology
2012 Pan American Health Care Exchanges, PAHCE 2012 - Conference, Workshops, and Exhibits. Cooperation / Linkages: An Independent Forum for Patient Aare and Technology Support | Year: 2012

Anthropogenic activities associated to population growth impact overall health and contribute to elevated rates of cardiovascular and respiratory diseases. In this paper we propose the Lung Sound Automatic Verification (LSAV), and other modalities to represent acoustic lung signals obtained by auscultation using a digital stethoscope. The utilization of quantiles allowed a) an easier and objective assessment with smaller computational demand, b) building of less-complex Gaussian Mixed Models (GMM) than those reported previously, and c) to reach practically negligible error in healthy LS verification. These approaches relate the lung sound energy to its characteristic frequency components, which in addition to a reliable verification technique simplified the normal lung sound recognition. Once the LS are evaluated, it would be possible to simplify classification if an individual auscultatory evaluation falls into the category of normal or abnormal indicators thus providing a tool for broader medical evaluation which does not rely, as it is often the case, on a qualitative and subjective description of these sounds. © 2012 IEEE.

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