Fatty Liver (part 2): Clinical Approach and Treatment

Patients with fatty liver are almost always asymptomatic; aminotransferases are usually elevated two to five times the expected value and are an important cause of initial consultation. All images can show fatty liver, and liver biopsy remains the gold standard for diagnosis. In any patient, non-invasive tests are an excellent alternative to biopsy to determine the degree of liver fibrosis and establish the stage of fibrogenesis. Weight loss and exercise are the fundamental pillars of the indicated treatment for all patients with overweight or obesity; a weight loss between 5% and 10% and a diet with caloric restriction of 500-1000 kcal/day, low in saturated fat and rich in Mediterranean diet products such as fruit, fish, vegetables, nuts, olive oil, among others, are recommended. There are other treatments, such as pharmacological measures and endoscopic and surgical procedures.

Los pacientes con hígado graso son casi siempre asintomáticos, las aminotransferasas usualmente están elevadas dos a cinco veces el valor normal y son una causa importante de consulta inicial. Todas las imágenes pueden evidenciar el hígado graso y la biopsia hepática sigue siendo la prueba de oro para su diagnóstico. En cualquier paciente las pruebas no invasivas son una excelente alternativa a la biopsia para determinar el grado de fibrosis hepática y establecer en qué etapa de la fibrogénesis se encuentra. La pérdida de peso y el ejercicio son los pilares fundamentales del tratamiento indicado para todos los pacientes con sobrepeso u obesidad; se recomienda una pérdida de peso entre 5% y 10% del peso corporal y una dieta con restricción calórica de 500-1000 kcal/día, baja en grasas saturadas y rica en productos de la dieta mediterránea como fruta, pescado, verduras, frutos secos, aceite de oliva, entre otros. Hay otros tratamientos como las medidas farmacológicas y los procedimientos endoscópicos y quirúrgicos.

Urine metabolomics study of hepatocellular carcinoma / 中华肿瘤杂志

Objective: To investigate the urinary small molecular metabolites and their metabolic characteristics of patients with hepatocellular carcinoma (HCC). Methods: High throughput ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was used to detect the small molecular metabolites in urine of healthy control (n=10), patients with hepatic hemangioma (n=10) and patients with HCC (n=10). The orthogonal projections to latent structures-discriminant analysis (OPLS-DA), hierarchical cluster analysis of multivariate analysis and univariate analysis were used to analyze the differential metabolites of the three groups. Results: The metabolic profiles of the three groups showed that the total of 381 differential metabolites were identified and divided into 96 up-regulated metabolites and 285 down-regulated metabolites. There were 55 urinary metabolites specifically related to HCC. Twenty-one of them were significantly up-regulated, including Acetyl-DL-Leucine, Ala Asp, HoPhe-Gly-OH, while 34 were significantly down-regulated, including Selenocystathionine, Met Trp Met Cys, Valsartan acid and so on. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the differential metabolites were mainly enriched in glutamine/glutamate metabolism, lysine biosynthesis, tricarboxylic acid cycle and purine metabolism. Conclusions: The occurrence of HCC is accompanied by the abnormalities of multiple metabolites and metabolic pathways. The analysis of the characteristic metabolic profile of urine in patients with HCC is helpful to find metabolic markers and potential therapeutic targets for liver cancer.

Role of acoustic radiation force impulse elastography, aminotransferase to platelet ratio index and fibrotest for the assessment of significant fibrosis and cirrhosis in chronic liver disease

Background: Accurate grading of hepatic fibrosis is important for the application of appropriate intervening strategy. Liver biopsy is the golden standard of fibrotic grading, however wide clinical application is hindered by its inherent drawbacks. Biomechanical-based ultrasonic elastography has received mass attention. However, several clinical studies found that the sole application of ultrasonic elastography may bring evident errors in diagnosing hepatic fibrosis. It is suggested that a combination of ultrasonic elastography and serum liver functions tests holds the potential to overcome those disadvantages. Aims and objectives was to study the diagnostic accuracy of ultrasonography elastography, APRI, fibrotest for significant fibrosis and cirrhosis in patients with chronic liver disease and established the correlation between ARFI elastography, APRI, Fibrotest in grading of liver fibrosisMethods: Sixty three patients with chronic liver disease were studied.  Liver stiffness was evaluated with ARFI elastography. Histologic staging of liver fibrosis served as the reference standard except a very few cirrhotic patients who were graded as cirrhotic on the basis of clinical examination. The required APRI, Fibrotest parameters and relevant clinical history was recorded.  Fibrosis stage was assessed according to the METAVIR classification.Results: ARFI, APRI, and Fibrotest demonstrated a significant correlation with the histological stage. According to ARFI and APRI for evaluating fibrotic stages more than F2, ARFI showed an enhanced diagnostic accuracy than APRI. The combined measurement of ARFI and APRI exhibited better accuracy than ARFI alone when evaluating ≥ F2 fibrotic stage that showed  significant concordance  i.e. 79.3% cases,  out of which 69.8% of total cases were correctly diagnosed on comparison with the gold standard. Fibrotest and ARFI elastography show significant concordance in grading of fibrosis i.e. 82.5%. Cases out of which 68.3% of total cases were correctly diagnosed on comparison with the gold standard.Conclusions: APRI, ARFI, and fibrotest are novel tools among non-invasive modalities to rule out significant fibrosis and cirrhosis in patients with chronic liver disease. ARFI with APRI and ARFI with fibrotest showed enhanced diagnostic accuracy than ARFI or APRI or fibrotest alone for significant liver fibrosis.

Plasma Levels of K18 Fragments Do Not Correlate with Alcoholic Liver Fibrosis

BACKGROUND/AIMS: Noninvasive markers of liver fibrosis in alcoholic liver disease (ALD) are crucial to establish early intervention. Previous studies have suggested that plasma levels of cleaved keratin-18 (K18; M30) fragments can predict the severity of liver disease. The aim of this study was to correlate plasma M30 levels with stages of liver fibrosis in ALD. METHODS: Patients with ALD (n=139, 79.1% males) and liver histology were included, and plasma samples were collected to quantify plasma M30 levels. Patients were stratified into five groups by fibrosis stage (F0=14; F1=15; F2=35; F3=17; and F4=58) according to the Kleiner score. Differences between groups were evaluated using the chi-square test or analysis of variance. Trends by fibrosis stage were calculated by logistic regression analysis, and sensitivity, specificity and positive and negative predictive values were determined. RESULTS: There were no significant differences in M30 levels among fibrosis stages. The correlation between plasma M30 levels and fibrosis was poor (Pearson’s correlation coefficient=0.13, Spearman rho=0.20 [p=0.02]), and M30 levels did not correlate with alcohol-specific histological features. However, significant correlations of M30 levels with aspartate aminotransferase (Spearman rho=0.653, p 200 U/L reveal a sensitivity for predicting cirrhosis of 84.5% with a negative predictive value of 73.5%. CONCLUSIONS: Plasma M30 levels are often elevated in ALD and correlate with serum transaminases but do not reflect fibrosis. The usefulness as a prognostic marker awaits evaluation in prospective studies.

Establishment and evaluation of a novel and non-invasive diagnostic model on cirrhotic patients / 中华肝胆外科杂志

Objective To establish and evaluate a novel and non-invasive diagnostic model using routine laboratory serological indexes in cirrhotic patients.Methods A retrospective study was conducted on 1044 consecutive patients with hepatocellular carcinoma (HCC) treated by hepatectomy in the Affiliated Tumor Hospital of Guangxi Medical University from September 2013 to December 2016.These patients were divided into a training cohort (n =783) and a validation cohort (n =261) using the 3 ∶ 1 matching principle.Logistic regression analysis was used to identify independent risk factors related to occurrence of cirrhosis in the training cohort,and then a PPH score was established.The accuracy of the model in predicting cirrhosis in two groups was evaluated respectively by the area under the receiver operating characteristic curve (AUC) and goodness of fit,and compared with the following commonly used predictive systems:the model for endstage liver disease (MELD) score,fibrosis index based on 4 factor score (FIB-4),Forns score and aspartate aminotransferase to platelet ratio index score (APRI).Results Univariate and multivariate Logistic regression analysis in the training cohort showed prothrombin time,platelet count and hepatitis B surface antigen positivity were closely related to occurrence of cirrhosis.The accuracy of the PPH score (AUC =0.705) in diagnosing cirrhosis in the training cohort was significantly better than the MELD score (AUC =0.557),APRI score (AUC =0.598),FIB-4 score (AUC =0.597) and Forns score (AUC =0.665).Similar results were obtained in the validation cohort (AUC:0.702 vs 0.554 vs 0.624 vs 0.634 vs 0.580).The goodness of fit indicated that there was no significant difference between the actual and predicted values of cirrhosis in the two cohorts,and the model was in good agreement.Conclusions A novel and non-invasive model for the diagnosis of cirrhosis was successfully established.The accuracy of this model in diagnosing cirrhosis was better than the MELD,APRI,Fib-4 and Forns scores.This model has significance in guiding clinical treatment decision in HCC patients with cirrhosis.

Usefulness of Transient Elastography for Non-Invasive Diagnosis of Liver Fibrosis in Pediatric Non-Alcoholic Steatohepatitis

BACKGROUND: Transient elastography (FibroScan®) is a non-invasive and rapid method for assessing liver fibrosis. While the feasibility and usefulness of FibroScan® have been proven in adults, few studies have focused on pediatric populations. We aimed to determine the feasibility and usefulness of FibroScan® in Korean children. METHODS: FibroScan® examinations were performed in 106 children (age, 5–15 years) who visited the Konyang University Hospital between June and September 2018. Liver steatosis was measured in terms of the controlled attenuation parameter (CAP), while hepatic fibrosis was evaluated in terms of the liver stiffness measurement (LSM). Children were stratified into obese and non-obese controls, according to body mass index (≥ or 95% percentile) (P 5.5 kPa), whereas the remaining 29 did not (LSM < 5.5 kPa). Obese children with fibrosis had higher levels of AST (73.57 ± 56.00 vs. 39.86 ± 31.93 IU/L; P = 0.009), ALT (132.47 ± 113.88 vs. 48.66 ± 51.29 IU/L; P = 0.001), and gamma-glutamyl transferase (106.67 ± 69.31 vs. 28.80 ± 24.26 IU/L; P = 0.042) compared to obese children without fibrosis. LSM had high and significant correlation (P < 0.05) with AST, ALT, homeostasis model assessment for insulin resistance, and AST-to-platelet ratio index. CONCLUSION: FibroScan® is clinically feasible and facilitates non-invasive, rapid, reproducible, and reliable detection of hepatic steatosis and liver fibrosis in the Korean pediatric population.

Impact of hepatoprotective drugs on the performance of APRI for diagnosing liver fibrosis in chronic hepatitis B / 中华实验和临床病毒学杂志

Objective@#To investigate the impact of hepatoprotective drugs on the performance of APRI for diagnosing liver fibrosis in chronic hepatitis B (CHB).@*Methods@#Patients with CHB who underwent a percutaneous liver biopsy were recruited and divided into hepatoprotective drugs using group and hepatoprotective drugs free group. Grouping was carried out according to the types of commonly used hepatoprotective drugs, and controls were matched for each groups by stage of liver fibrosis and age from hepatoprotective drugs free group. The performance of APRI for diagnosing significant fibrosis and cirrhosis was evaluated and compared between each experimental groups and control groups using receiver operating characteristic (ROC) curves.@*Results@#A total of 1447 patients were enrolled, including 60 using glycyrrhizin, 54 using silymarin, 63 using traditional Chinese medicine (TCM) containing schisandra, and 113 using more than one hepatoprotective drug. In patients using glycyrrhizin, the sensitivity of APRI to predict significant fibrosis was higher than its control group. In patients using more than one hepatoprotective drug, the sensitivity of APRI to exclude significant fibrosis was higher than its control group; the area under ROC curve of APRI to diagnose significant fibrosis, the specificity of APRI to exclude and predict significant fibrosis were all lower than its control group. In patients using glycyrrhizin and patients using more than one hepatoprotective drug, the specificity of APRI to exclude cirrhosis were both lower than their control groups. In patients using silymarin and patients using TCM, the performance of APRI to diagnose significant fibrosis and cirrhosis was comparable with their control groups.@*Conclusions@#Glycyrrhizin and combination of hepatoprotective drugs would have significant impact on the performance of APRI for diagnosing liver fibrosis in CHB, silymarin and TCM containing schisandra would have less impact.

Characteristics, diagnosis and management of concomitant fatty liver in hepatitis B patients / 中华临床感染病杂志

Fatty liver is increasingly common in patients with chronic hepatitis B (CHB) in China. The impact of hepatitis B virus infection on fatty liver and metabolism , in turns the impact of fatty liver and metabolic factors on the development and treatment of patients with CHB are of great concern .The causes of abnormal elevation of serum aminotransferases in patients with CHB and fatty liver should be carefully determined to make appropriate therapeutic choices in these conditions.In order to make personalized treatment and follow-up measures, the non-invasive diagnosis for nonalcoholic steatohepatitis in patients with chronic hepatitis B virus infection requires further studies.

Progress in Non-invasive Diagnosis and Assessment of Non-alcoholic Fatty Liver Disease / 胃肠病学

Non-alcoholic fatty liver disease (NAFLD)is a clinical syndrome characterized by hepatic fat deposition, and not caused by chronic heavy drinking and other liver damage factors. The pathogenesis of NAFLD is associated with environmental,genetic,immune and other various factors. Early diagnosis is helpful not only for distinguishing between simple non-alcoholic fatty liver (NAFL)and non-alcoholic steatohepatitis (NASH),but also for grading the extent of NAFLD lesion and delaying its further development. This article reviewed the clinical research progress of non-invasive diagnosis and evaluation of NAFLD.

Value of Serum miR-192 and miR-29a for Non-invasive Diagnosis of Liver Cirrhosis / 胃肠病学

Background:Diagnosis of liver cirrhosis in early stage with early intervention may stabilize disease progression, avoiding or delaying the occurrence of decompensation. Seeking non-invasive serum biomarkers is becoming an important topic in the diagnosis and assessment of liver cirrhosis. Aims:To study the value of serum miR-192 and miR-29a as non-invasive biomarkers for the diagnosis of liver cirrhosis. Methods:Differentially expressed serum miRNAs between patients with liver cirrhosis and healthy controls were screened through online literature retrieval and then confirmed by real-time PCR. Serum levels of two confirmed miRNAs,miR-192 and miR-29a were analyzed in 120 patients with liver cirrhosis and 76 healthy volunteers by real-time PCR. A mathematical model of combined detection of miR-192 and miR-29a for diagnosis of liver cirrhosis was established by binary logistic regression. The diagnostic performance of various non-invasive serum indicators was evaluated by ROC curve analysis. Results:Compared with healthy controls,expression level of serum miR-192 in cirrhotic patients was significantly increased and that of serum miR-29a was significantly reduced(P ﹤ 0. 001). The diagnostic performance of risk score obtained from mathematical model of combined detection of serum miR-192 and miR-29a was superior to that of single miRNA detection or other non-invasive serum indicators,such as APRI,FIB-4 and ARR,the areas under ROC curve of the above mentioned indicators were 0. 968,0. 887,0. 933,0. 796,0. 793,and 0. 571,respectively. Serum levels of miR-192,miR-29a and the risk score of their combined detection were significantly correlated with the stage of liver cirrhosis according to the Child-Pugh classification( P ﹤ 0. 05). Conclusions:Serum miR-192,miR-29a and the risk score of their combined detection might be novel non-invasive biomarkers for the diagnosis and assessment of liver cirrhosis.

Controversias en el diagnóstico de enfermedad por hígado graso no alcohólico / Controversies in the diagnosis of non-alcoholic fatty liver disease

There has been an increase in the prevalence of nonalcoholic fatty liver disease (NAFLD) throughout the western world and especially in Latin America. This condition is associated with metabolic syndrome, risk of diabetes, cardiovascular risk and extrahepatic cancer. However, in patients with NAFLD, risk of mortality from diseases affecting the liver does not exceed 5 percent in contrast to 60 percent when advanced fibrosis is present. Only 10 to 20 percent of patients with NAFLD have non-alcoholic steatohepatitis (NASH), a condition that can potentially progress to fibrosis and cirrhosis. The non-invasive diagnostic tools for discriminating current patients at risk of progression to advanced fibrosis are sub-optimal. Clinical variables and routine laboratory tests help in detecting NAFLD but do not allow discrimination of NASH patients. New diagnostic tools could allow prediction of NASH such as markers of oxidative stress, inflammatory markers and markers of apoptosis. Regarding liver fibrosis biomarkers, there are indirect markers that are related to the degree of liver function and direct markers that reflect the dynamics of extracellular matrix. Imaging methods such as ultrasound-based elastography, (ARFI) and magnetic resonance elastography have shown a good correlation with the degree of fibrosis. Finally various predictor models that combine clinical and laboratory variables have a very good correlation with the degree of fibrosis. Although there is still some controversy on its clinical utility, liver biopsy still plays a role in NAFLD severity assessment for initiation of drug therapy.

Se ha registrado un aumento en la prevalencia de la enfermedad por hígado graso no alcohólico HGNA (NAFLD, por su sigla en inglés) en todo el mundo occidental y especialmente en Latinoamérica. Esta condición se relaciona con síndrome metabólico, riesgo de diabetes, riesgo cardiovascular y cáncer extrahepático. Sin embargo, en pacientes con HGNA el riesgo de mortalidad por enfermedades que afectan al hígado no supera el 5 por ciento en contraste con 60 por ciento cuando hay fibrosis avanzada. Sólo 10 a 20 por ciento de los pacientes presenta esteatohepatitis no alcohólica EHNA (NASH, por su sigla en inglés), una condición que potencialmente puede progresar a fibrosis y cirrosis. Las herramientas de diagnóstico no invasivo actuales para discriminar pacientes con riesgo de progresión a fibrosis avanzada son subóptimas. Las variables clínicas y exámenes de laboratorio habituales ayudan en la detección de HGNA,pero no permiten discriminar pacientes con EHNA. Nuevas herramientas diagnósticas podrían permitir predecir EHNA como marcadores de estrés oxidativo, marcadores de inflamación y de apoptosis. De los marcadores de fibrosis existen los indirectos que se relacionan con el grado de función hepática, marcadores directos que reflejan la dinámica de la matriz extracelular. Los métodos de imagen como la elastografía por ultrasonido (ARFI), elastografía por resonancia magnética, han demostrado una buena correlación con el grado de fibrosis. Finalmente, diversos índices que combinan variables clínicas y de laboratorio tienen una muy buena correlación con el grado de fibrosis. La biopsia aun cumple un rol a pesar de la controversia en su real necesidad para iniciar tratamiento.

Recognition of heart sound based on distribution of Choi-Williams

IntroductionTo realize noninvasive diagnosis and early diagnosis of coronary heart disease, the study proposes a new time-frequency method for analyzing heart sound signals. This method is based on Choi-Williams Distribution (CWD).MethodsCWD distribution is developed and modified from Wigner Ville distribution (WVD). To solve the problem of cross-term interference existing in WVD there is an improved version of WVD, called Choi-Williams Distribution (CWD), which introduces the smoothing window as the kernel function and deals with the time-frequency analysis of heart sound signal.ResultsThe improved method has good performance and can be implemented simply without much increase of operation complexity.ConclusionIn this paper, 21 cases of heart sound signals are acquired from the outpatients and hospitalized patients with coronary heart diseases. The research results of 21 cases show that the CWD method can be used to analyze heart sounds. It accurately identifies the 9 cases of heart sounds of health people and 12 cases of heart sounds of patients with coronary heart disease. Besides, the CWD displays obvious differences between heart sounds of healthy people and abnormal heart sounds. The contour line of heart sounds from healthy people shows the following characteristics: concise, columnar and non-divergence; while the contour line of abnormal heart sounds is divergent and has many columnar links. These research shows that CWD method can effectively distinguish heart sounds between healthy people and patients with coronary heart disease.

Serum complement C3 and C4 levels for predicting severity of hepatic fibrosis in patients with chronic hepatitis B / 中华临床感染病杂志

ObjectiveTo investigate the clinical value of serum complement C3 and C4 levels for predicting the severity of hepatic fibrosis in patients with chronic hepatitis B.MethodsHistopathological diagnosis was confirmed in 442 patients with chronic hepatitis B.Serum complement C3 and C4 levels were determined by Beckman-Coulter Immage 800 immunochemistry system.ROC curve was used to analyze the value of serum complement C3 and C4 levels in predicting the severity of hepatic fibrosis.ResultsThe areas under ROC curve of complement C3 and C4 for predicting significant fibrosis ( ≥ S2),severe fibrosis ( ≥ S3) and cirrhosis (S4) were all significantly larger than the area under diagonal reference line ( P =0.009,0.000,0.000 and P =0.005,0.000,0.000,respectively).According to ROC curves,the optimal cut-offs of serum complement G3 for predicting severe fibrosis and cirrhosis were ≤0.74 g/L and ≤0.64 g/L,and the corresponding sensitivity,specificity,positive predictive value,negative predictive value,accuracy were 0.585,0.681,0.617,0.650,0.636 and 0.509,0.775,0.423,0.830,0.710,respectively.The optimal cut-offs of serum complement C4 for predicting severe fibrosis and cirrhosis were ≤0.14 g/L and ≤0.12 g/L,and the corresponding sensitivity,specificity,positive predictive value,negative predictive value,accuracy were 0.565,0.634,0.576,0.623,0.602 and 0.463,0.781,0.407,0.818,0.704,respectively.ConclusionSerum complement C3 and C4 may be used for predicting severe fibrosis and cirrhosis in patients with chronic hepatitis B,but its stability and reliability need to be improved.

DNA identification of Leishmania (Viannia) braziliensis in human saliva from a patient with American cutaneous leishmaniasis

This study aims to report the amplification of the DNA of Leishmania (V.) braziliensis, using polymerase chain reaction, obtained from the saliva of a patient with American cutaneous leishmaniasis who did not present any lesion in the oral mucosa. Amplification produced fragments of 103 bp, an estimated size employing Leishmania (V.) braziliensis primers (b1 e b2). The present results revealed, for the first time, that the in vitro amplification of Leishmania DNA using samples from the salivary fluid of a patient with American cutaneous leishmaniasis is possible. However, more studies are required with a larger number of participants to evaluate the usefulness of saliva as a non-invasive sample for PCR. The development of such non-invasive technique is necessary for the diagnosis of many diseases in the future, especially infectious and parasitic ones.

Evaluation of a New Diagnostic Test for Invasive Fungal Infections Using Prophenoloxydase System to Measure (1->3)-beta-D-glucan Concentration

BACKGROUND: Prognosis of invasive fungal infection is supposed to be better when diagnosed earlier. (1->3)-beta-D-glucan (BDG) test is considered useful in early diagnosis of invasive fungal infections among high-risk patients. A new diagnostic test using prophenoloxydase system to measure BDG level is developed. A study was performed to evaluate clinical usefulness of this new diagnostic test. MATERIALS AND METHODS: 15 patients of confirmed invasive fungal infections and 38 healthy normal volunteers were enrolled. Plasma or serum BDG concentrations were measured using prophenoloxydase system. Assays for intra-run variability and inter-run variability were performed. A cut-off value was determined and sensitivity and specificity of the test were evaluated. RESULTS: A cut-off value of 94.90 pg/mL was determined. Sensitivity and specificity of the test were 86.7% and 52.6%, respectively. Statistical analyses of inter-run variability and intra-run variability revealed the test is reliable (P< or =0.001). CONCLUSION: BDG test using prophenoloxydase system is a sensitive and reliable test in non-invasive detection of invasive fungal infection.

Evaluation of a New Diagnostic Test for Invasive Fungal Infections Using Prophenoloxydase System to Measure (1->3)-beta-D-glucan Concentration

BACKGROUND: Prognosis of invasive fungal infection is supposed to be better when diagnosed earlier. (1->3)-beta-D-glucan (BDG) test is considered useful in early diagnosis of invasive fungal infections among high-risk patients. A new diagnostic test using prophenoloxydase system to measure BDG level is developed. A study was performed to evaluate clinical usefulness of this new diagnostic test. MATERIALS AND METHODS: 15 patients of confirmed invasive fungal infections and 38 healthy normal volunteers were enrolled. Plasma or serum BDG concentrations were measured using prophenoloxydase system. Assays for intra-run variability and inter-run variability were performed. A cut-off value was determined and sensitivity and specificity of the test were evaluated. RESULTS: A cut-off value of 94.90 pg/mL was determined. Sensitivity and specificity of the test were 86.7% and 52.6%, respectively. Statistical analyses of inter-run variability and intra-run variability revealed the test is reliable (P< or =0.001). CONCLUSION: BDG test using prophenoloxydase system is a sensitive and reliable test in non-invasive detection of invasive fungal infection.

Research on Noninvasive Diagnosis for Coronary Heart Disease Based on Neural Network / 航天医学与医学工程

Objective To extract characteristic parameters of ECG signals a new method of non-invasive diagnosis for coronary heart disease with artificial neural network. Methods ECG signals were digitized with A/D converter and filtered to eliminating the noise. Span of QRS interval, R-R interval,and voltage of S-T segment of filtered ECG were detected. These 3 characteristics were as the input parameters of the input layer. Samples were trained with an improved 3-layers back propagation(BP) artificial neural network, as trained samples. The non-trained samples were recognized with these BP neural networks. Results After 12 samples had been trained about 1500 times, the BP neural network could accurately distinguish samples of coronary heart disease from the trained samples and also recognize 20 non-trained samples, 19 to be correct except one. Conclusion It is showed that based on BP network and characteristic parameters of ECG, a new and promising method of non-invasive diagnosis for coronary heart disease has been found.