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1.
IEEE Trans Inf Technol Biomed ; 15(1): 11-8, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21075730

ABSTRACT

In this paper, a methodology is described in order to investigate the performance of empirical mode decomposition (EMD) in biomedical signals, and especially in the case of electrocardiogram (ECG). Synthetic ECG signals corrupted with white Gaussian noise are employed and time series of various lengths are processed with EMD in order to extract the intrinsic mode functions (IMFs). A statistical significance test is implemented for the identification of IMFs with high-level noise components and their exclusion from denoising procedures. Simulation campaign results reveal that a decrease of processing time is accomplished with the introduction of preprocessing stage, prior to the application of EMD in biomedical time series. Furthermore, the variation in the number of IMFs according to the type of the preprocessing stage is studied as a function of SNR and time-series length. The application of the methodology in MIT-BIH ECG records is also presented in order to verify the findings in real ECG signals.


Subject(s)
Electrocardiography/methods , Signal Processing, Computer-Assisted , Algorithms , Computer Simulation , Humans
2.
Pac Symp Biocomput ; : 243-54, 2008.
Article in English | MEDLINE | ID: mdl-18229690

ABSTRACT

Traditionally, the elucidation of genes involved in maturation and aging has been studied in a temporal fashion by examining gene expression at different time points in an organism's life as well as by knocking out, knocking in, and mutating genes thought to be involved. Here, we propose an in silico method to combine clinical electronic medical record (EMR) data and gene expression measurements in the context of disease to identify genes that may be involved in the process of human maturation and aging. First we show that absolute lymphocyte count may serve as a biomarker for maturation by using statistical methods to compare trends among different clinical laboratory tests in response to an increase in age. We then propose using the rate of decay for absolute lymphocyte count across 12 diseases as a proxy for differences in aging. We correlate the differing rates with gene expression across the same diseases to find maturation/aging related genes. Among the 53 genes with strongest correlations between expression profile and change in rate of decay, we found genes previously implicated in the process of aging, including MGMT (DNA repair), TERF2 (telomere stability), POLD1 (DNA replication and repair), and POLG (mtDNA replication).


Subject(s)
Aging/genetics , Gene Expression Profiling/statistics & numerical data , Genetic Markers , Hospital Records , Medical Records Systems, Computerized , Adolescent , Aging/blood , Analysis of Variance , Child , Child, Preschool , Computational Biology , Humans , Infant , Infant, Newborn , Lymphocyte Count
3.
Int J Telemed Appl ; 2008: 417870, 2008.
Article in English | MEDLINE | ID: mdl-19132096

ABSTRACT

The present paper studies the prospective and the performance of a forthcoming high-speed third generation (3.5G) networking technology, called enhanced uplink, for delivering mobile health (m-health) applications. The performance of 3.5G networks is a critical factor for successful development of m-health services perceived by end users. In this paper, we propose a methodology for performance assessment based on the joint uplink transmission of voice, real-time video, biological data (such as electrocardiogram, vital signals, and heart sounds), and healthcare records file transfer. Various scenarios were concerned in terms of real-time, nonreal-time, and emergency applications in random locations, where no other system but 3.5G is available. The accomplishment of quality of service (QoS) was explored through a step-by-step improvement of enhanced uplink system's parameters, attributing the network system for the best performance in the context of the desired m-health services.

4.
AMIA Annu Symp Proc ; : 115-9, 2007 Oct 11.
Article in English | MEDLINE | ID: mdl-18693809

ABSTRACT

The severity of diseases has often been assigned by direct observation of a patient and by pathological examination after symptoms have appeared. As we move into the genomic era, the ability to predict disease severity prior to manifestation has improved dramatically due to genomic sequencing and analysis of gene expression microarrays. However, as the severity of diseases can be exacerbated by non genetic factors, the ability to predict disease severity by examining gene expression alone may be inadequate. We propose the creation of a "clinarray" to examine phenotypic expression in the form of clinical laboratory measurements. We demonstrate that the clinarray can be used to distinguish between the severities of patients with cystic fibrosis and those with Crohn's disease by applying unsupervised clustering methods that have been previously applied to microarrays.


Subject(s)
Clinical Laboratory Techniques , Crohn Disease/classification , Cystic Fibrosis/classification , Phenotype , Severity of Illness Index , Crohn Disease/diagnosis , Crohn Disease/genetics , Cystic Fibrosis/diagnosis , Cystic Fibrosis/genetics , Down Syndrome/classification , Down Syndrome/diagnosis , Down Syndrome/genetics , Humans , Medical Records Systems, Computerized , Prognosis
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