RESUMO
This study proposed a noninvasive blood glucose estimation system based on dual-wavelength photoplethysmography (PPG) and bioelectrical impedance measuring technology that can avoid the discomfort created by conventional invasive blood glucose measurement methods while accurately estimating blood glucose. The measured PPG signals are converted into mean, variance, skewness, kurtosis, standard deviation, and information entropy. The data obtained by bioelectrical impedance measuring consist of the real part, imaginary part, phase, and amplitude size of 11 types of frequencies, which are converted into features through principal component analyses. After combining the input of seven physiological features, the blood glucose value is finally obtained as the input of the back-propagation neural network (BPNN). To confirm the robustness of the system operation, this study collected data from 40 volunteers and established a database. From the experimental results, the system has a mean squared error of 40.736, a root mean squared error of 6.3824, a mean absolute error of 5.0896, a mean absolute relative difference of 4.4321%, and a coefficient of determination (R Squared, R2) of 0.997, all of which fall within the clinically accurate region A in the Clarke error grid analyses.
Assuntos
Glicemia , Fotopletismografia , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial/métodos , Impedância Elétrica , Humanos , Redes Neurais de Computação , Fotopletismografia/métodosRESUMO
OBJECTIVE: To investigate the association of predisposing and protective HLA-DRB1 alleles with rheumatoid arthritis (RA) and its clinical markers in a Taiwanese population. METHODS: A total of 273 patients with RA and 480 healthy controls, all of Taiwanese origin, were genotyped for HLA-DRB1 alleles by polymerase chain reaction and sequence-based typing assays. The associations between RA and HLA-DRB1 alleles and genotypes were investigated by chi-squared test. RESULTS: The DRB1*0405 and *1001 phenotypes showed the most significant associations with RA (OR 4.04, 95% CI 2.84-5.77, pc = 3.2 10(-14); OR 5.25, 95% CI 2.10-13.06, pc = 3.0 10(-3), respectively). Individuals carrying single or double doses of the shared epitope (SE/non-SE or SE/SE) had higher risks of RA. The compound heterozygote of DRB1*0405/*1001 showed the largest increase in RA risk (OR 15.8, 95% CI 2.48-100.7, pc = 0.004). Single or double doses of SE alleles were significantly associated with a higher bone erosion rate. Rheumatoid factor positivity and bone erosion were more frequent in patients with at least one copy of DRB1*0405. CONCLUSION: Our results show that SE-encoding HLA-DRB1*0405 and *1001 are associated with RA in a Taiwanese population; this is the first time DRB1*1001 has been described in persons of Asian ethnicity. Heterozygotes of DRB1*0405 and *1001 predicted the strongest susceptibility to RA, suggesting that this genotype enhances susceptibility to RA in Taiwanese.