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1.
Br J Radiol ; : 20190558, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31957473

RESUMO

OBJECTIVE: To build and validate a CT radiomic model for pre-operatively predicting lymph node metastasis in early cervical carcinoma. METHODS AND MATERIALS: A data set of 150 patients with Stage IB1 to IIA2 cervical carcinoma was retrospectively collected from the Nanfang hospital and separated into a training cohort (n = 104) and test cohort (n = 46). A total of 348 radiomic features were extracted from the delay phase of CT images. Mann-Whitney U test, recursive feature elimination, and backward elimination were used to select key radiomic features. Ridge logistics regression was used to build a radiomic model for prediction of lymph node metastasis (LNM) status by combining radiomic and clinical features. The area under the receiver operating characteristic curve (AUC) and κ test were applied to verify the model. RESULTS: Two radiomic features from delay phase CT images and one clinical feature were associated with LNM status: log-sigma-2-0 mm-3D_glcm_Idn (p = 0.01937), wavelet-HL_firstorder_Median (p = 0.03592), and Stage IB (p = 0.03608). Radiomic model was built consisting of the three features, and the AUCs were 0.80 (95% confidence interval: 0.70 ~ 0.90) and 0.75 (95% confidence intervalI: 0.53 ~ 0.93) in training and test cohorts, respectively. The κ coefficient was 0.84, showing excellent consistency. CONCLUSION: A non-invasive radiomic model, combining two radiomic features and a International Federation of Gynecology and Obstetrics stage, was built for prediction of LNM status in early cervical carcinoma. This model could serve as a pre-operative tool. ADVANCES IN KNOWLEDGE: A noninvasive CT radiomic model, combining two radiomic features and the International Federation of Gynecology and Obstetrics stage, was built for prediction of LNM status in early cervical carcinoma.

2.
Ann Nutr Metab ; 75(3): 187-194, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31743929

RESUMO

OBJECTIVE: Our study aimed to compare the predictive value of waist-to-height ratio (WHtR) for hyperuricemia with body mass index (BMI) and waist circumference (WC). METHODS: This is a cross-sectional study of 9,206 South China residents (male/female: 4,433/4,773) aged 18-89 years recruited during years 2009-2010 and 2014-2015. Anthropometric measurements, serum uric acid, blood pressure, and plasma glucose, lipid, lipoprotein, and transferase levels were measured. Receiver operating characteristic (ROC) curve and logistic regression analyses were applied to evaluate the predictive values of anthropometric indices for hyperuricemia. RESULTS: The prevalence of hyperuricemia increased significantly with higher quartiles of WHtR in both genders. The best cutoff points of WHtR to predict hyperuricemia are 0.52 for men and 0.49 for women and differed between different BMI and WC stratums. Although there was no significant difference between the area under the ROC curves, subjects in the top quartile of WHtR were at a highest risk of hyperuricemia (p for linear trend <0.001) and the adjusted ORs of WHtR (2.24-2.77 in men and 2.66-4.95 in women) were higher than those of BMI or WC in the multivariable regression model. CONCLUSIONS: WHtR was an independent and better predictor of hyperuricemia compared with BMI and WC.

3.
J Healthc Eng ; 2019: 4501502, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31178987

RESUMO

Autonomic neural system (ANS) regulates the circulation to provide optimal perfusion of every organ in accordance with its metabolic needs, and the quantitative assessment of autonomic regulation is crucial for personalized medicine in cardiovascular diseases. In this paper, we propose the Dystatis to quantitatively evaluate autonomic regulation of the human cardiac system, based on homeostatis and probabilistic graphic model, where homeostatis explains ANS regulation while the probability graphic model systematically defines the regulation process for quantitative assessment. The indices and measurement methods for three well-designed scenarios are also illustrated to evaluate the proposed Dystatis: (1) heart rate variability (HRV), blood pressure variability (BPV), and respiration synchronization (Synch) in resting situation; (2) chronotropic competence indices (CCI) in graded exercise testing; and (3) baroreflex sensitivity (BRS), sympathetic nerve activity (SNA), and parasympathetic nerve activity (PNA) in orthostatic testing. The previous clinical results have shown that the proposed method and indices for autonomic cardiac system regulation have great potential in prediction, diagnosis, and rehabilitation of cardiovascular diseases, hypertension, and diabetes.

4.
Front Comput Neurosci ; 12: 69, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30186130

RESUMO

Motor system uses muscle synergies as a modular organization to simplify the control of movements. Motor cortical impairments, such as stroke and spinal cord injuries, disrupt the orchestration of the muscle synergies and result in abnormal movements. In this paper, the alterations of muscle synergies in subacute stroke survivors were examined during the voluntary reaching movement. We collected electromyographic (EMG) data from 35 stroke survivors, ranging from Brunnstrom Stage III to VI, and 25 age-matched control subjects. Muscle synergies were extracted from the activity of 7 upper-limb muscles via nonnegative matrix factorization under the criterion of 95% variance accounted for. By comparing the structure of muscle synergies and the similarity of activation coefficients across groups, we can validate the increasing activation of pectoralis major muscle and the decreasing activation of elbow extensor of triceps in stroke groups. Furthermore, the similarity of muscle synergies was significantly correlated with the Brunnstrom Stage (R = 0.52, p < 0.01). The synergies of stroke survivors at Brunnstrom Stage IV-III gradually diverged from those of control group, but the activation coefficients remained the same after stroke, irrespective of the recovery level.

5.
Technol Health Care ; 26(6): 909-920, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29914041

RESUMO

BACKGROUND: Hill-type musculotendon models are most commonly used in biomechanical simulations for their computational efficacy and efficiency. But these models are generally built for maximally-activated muscles and linearly scale muscle properties when applied to submaximal conditions. However, the precondition of this scaling, which is muscle activation and properties are independent each other, has been proven unreal in many studies. Actually, the maximal activation condition is not ubiquitous for muscles in vivo, so it is necessary to adapt the linear scaling approach to improve the model practicability. OBJECTIVE: This paper aimed at proposing two improved Hill-type musculotendon models that are better suited for submaximal conditions. METHOD: These two models were built by including the activation-force-length coupling and their biological accuracy and computation speed were evaluated by a series of benchmark simulations. RESULTS: Compared to experimental measurements, the percent root mean square errors of forces calculated by the two AFLC models were less than 13.98% and 13.81% respectively. However, the average running time of the second AFLC model was nearly 17 times that of the first one with only a little improvement in accuracy. CONCLUSION: The two AFLC models were validated more accurate than the common Hill-type model in submaximally activated conditions and the first one was recommended in the construction of upper-layer musculoskeletal models.


Assuntos
Simulação por Computador , Modelos Biológicos , Músculo Esquelético/fisiologia , Tendões/fisiologia , Fenômenos Biomecânicos , Humanos , Contração Muscular/fisiologia
6.
Sensors (Basel) ; 16(12)2016 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-27916853

RESUMO

This paper proposes a neuromusculoskeletal (NMS) model to predict individual muscle force during elbow flexion and extension. Four male subjects were asked to do voluntary elbow flexion and extension. An inertial sensor and surface electromyography (sEMG) sensors were attached to subject's forearm. Joint angle calculated by fusion of acceleration and angular rate using an extended Kalman filter (EKF) and muscle activations obtained from the sEMG signals were taken as the inputs of the proposed NMS model to determine individual muscle force. The result shows that our NMS model can predict individual muscle force accurately, with the ability to reflect subject-specific joint dynamics and neural control solutions. Our method incorporates sEMG and motion data, making it possible to get a deeper understanding of neurological, physiological, and anatomical characteristics of human dynamic movement. We demonstrate the potential of the proposed NMS model for evaluating the function of upper limb movements in the field of neurorehabilitation.


Assuntos
Articulação do Cotovelo/fisiologia , Músculo Esquelético/fisiopatologia , Reabilitação Neurológica/métodos , Eletromiografia , Humanos , Contração Isométrica/fisiologia , Masculino , Amplitude de Movimento Articular/fisiologia
7.
Technol Health Care ; 24 Suppl 2: S707-15, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27177101

RESUMO

BACKGROUND: Nowadays, stroke is a leading cause of disability in adults. Assessment of motor performance has played an important role in rehabilitation for post stroke patients. Therefore, it is quite important to develop an automatic assessment system of motor function. OBJECTIVE: The purpose of this study is to assess the performance of the single task upper-limb movements quantitatively among stroke survivors. METHODS: Eleven normal subjects and thirty-five subjects with stroke were involved in this study. The subjects, who were wearing the micro-sensor motion capture system, performed shoulder flexion in a sitting position. The system recorded three-dimensional kinematics data of limb movements in quaternions. By extracting the significant features from these data, we built a linear model to acquire the functional assessment score (FAS). RESULTS: All of the kinematics features have a significant statistical difference (P < 0.05) between patients and healthy people, while the feature values have a high correlation with Fugl-Meyer (FM) scores (r > 0.5, p < 0.05), indicating that these features are able to reflect the level of motion impairment. Furthermore, most samples of the linear model locate in the confidence interval after regression, with the residual approaching a normal distribution. These results show that the FAS is capable of motor function assessment for stroke survivors. CONCLUSION: These findings represent an important step towards a system that can be utilized for precise single task motor evaluation after stroke, applicable to clinical research and as a tool for rehabilitation.


Assuntos
Transtornos Motores/diagnóstico , Recuperação de Função Fisiológica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/fisiopatologia , Extremidade Superior/fisiopatologia , Retroalimentação Sensorial , Humanos , Transtornos Motores/etiologia , Acidente Vascular Cerebral/complicações
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