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1.
Sensors (Basel) ; 24(10)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38794016

RESUMO

Preprocessing plays a key role in Raman spectral analysis. However, classical preprocessing algorithms often have issues with reducing Raman peak intensities and changing the peak shape when processing spectra. This paper introduces a unified solution for preprocessing based on a convolutional autoencoder to enhance Raman spectroscopy data. One is a denoising algorithm that uses a convolutional denoising autoencoder (CDAE model), and the other is a baseline correction algorithm based on a convolutional autoencoder (CAE+ model). The CDAE model incorporates two additional convolutional layers in its bottleneck layer for enhanced noise reduction. The CAE+ model not only adds convolutional layers at the bottleneck but also includes a comparison function after the decoding for effective baseline correction. The proposed models were validated using both simulated spectra and experimental spectra measured with a Raman spectrometer system. Comparing their performance with that of traditional signal processing techniques, the results of the CDAE-CAE+ model show improvements in noise reduction and Raman peak preservation.

2.
Sensors (Basel) ; 23(20)2023 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-37896730

RESUMO

The robotic surgery environment represents a typical scenario of human-robot cooperation. In such a scenario, individuals, robots, and medical devices move relative to each other, leading to unforeseen mutual occlusion. Traditional methods use binocular OTS to focus on the local surgical site, without considering the integrity of the scene, and the work space is also restricted. To address this challenge, we propose the concept of a fully perception robotic surgery environment and build a global-local joint positioning framework. Furthermore, based on data characteristics, an improved Kalman filter method is proposed to improve positioning accuracy. Finally, drawing from the view margin model, we design a method to evaluate positioning accuracy in a dynamic occlusion environment. The experimental results demonstrate that our method yields better positioning results than classical filtering methods.


Assuntos
Procedimentos Cirúrgicos Robóticos , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Percepção
3.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 40(3): 499-507, 2023 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-37380389

RESUMO

The increasing prevalence of the aging population, and inadequate and uneven distribution of medical resources, have led to a growing demand for telemedicine services. Gait disturbance is a primary symptom of neurological disorders such as Parkinson's disease (PD). This study proposed a novel approach for the quantitative assessment and analysis of gait disturbance from two-dimensional (2D) videos captured using smartphones. The approach used a convolutional pose machine to extract human body joints and a gait phase segmentation algorithm based on node motion characteristics to identify the gait phase. Moreover, it extracted features of the upper and lower limbs. A height ratio-based spatial feature extraction method was proposed that effectively captures spatial information. The proposed method underwent validation via error analysis, correction compensation, and accuracy verification using the motion capture system. Specifically, the proposed method achieved an extracted step length error of less than 3 cm. The proposed method underwent clinical validation, recruiting 64 patients with Parkinson's disease and 46 healthy controls of the same age group. Various gait indicators were statistically analyzed using three classic classification methods, with the random forest method achieving a classification accuracy of 91%. This method provides an objective, convenient, and intelligent solution for telemedicine focused on movement disorders in neurological diseases.


Assuntos
Doença de Parkinson , Humanos , Idoso , Doença de Parkinson/diagnóstico , Envelhecimento , Algoritmos , Marcha , Extremidade Inferior
4.
Sensors (Basel) ; 22(1)2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-35009902

RESUMO

The hysteretic nonlinearity of pneumatic artificial muscle (PAM) is the main factor that degrades its tracking accuracy. This paper proposes an efficient hysteresis compensation method based on the active modeling control (AMC). Firstly, the Bouc-Wen model is adopted as the reference model to describe the hysteresis of the PAM. Secondly, the modeling errors are introduced into the reference model, and the unscented Kalman filter is used to estimate the state of the system and the modeling errors. Finally, a hysteresis compensation strategy is designed based on AMC. The compensation performances of the nominal controller with without AMC were experimentally tested on a PAM. The experimental results show that the proposed controller is more robust when tracking different types of trajectories. In the transient, both the overshoot and oscillation can be successfully attenuated, and fast convergence is achieved. In the steady-state, the proposed controller is more robust against external disturbances and measurement noise. The proposed controller is effective and robust in hysteresis compensation, thus improving the tracking performance of the PAM.


Assuntos
Músculos
5.
Sensors (Basel) ; 22(5)2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35271007

RESUMO

A multi-robot collaboration system can complete more complex tasks than a single robot system. Ensuring the calibration accuracy between robots in the system is a prerequisite for the effective inter-robot cooperation. This paper presents a dual-robot system for orthopedic surgeries, where the relationships between hand-eye, flange-tool, and robot-robot need to be calibrated. This calibration problem can be summarized to the solution of the matrix equation of AXB=YCZ. A combined solution is proposed to solve the unknown parameters in the equation of AXB=YCZ, which consists of the dual quaternion closed-form method and the iterative method based on Levenberg-Marquardt (LM) algorithm. The closed-form method is used to quickly obtain the initial value for the iterative method so as to increase the convergence speed and calibration accuracy of the iterative method. Simulation and experimental analyses are carried out to verify the accuracy and effectiveness of the proposed method.


Assuntos
Robótica , Algoritmos , Calibragem , Simulação por Computador , Mãos , Robótica/métodos
6.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 39(6): 1181-1188, 2022 Dec 25.
Artigo em Zh | MEDLINE | ID: mdl-36575088

RESUMO

Intelligent medical image segmentation methods have been rapidly developed and applied, while a significant challenge is domain shift. That is, the segmentation performance degrades due to distribution differences between the source domain and the target domain. This paper proposed an unsupervised end-to-end domain adaptation medical image segmentation method based on the generative adversarial network (GAN). A network training and adjustment model was designed, including segmentation and discriminant networks. In the segmentation network, the residual module was used as the basic module to increase feature reusability and reduce model optimization difficulty. Further, it learned cross-domain features at the image feature level with the help of the discriminant network and a combination of segmentation loss with adversarial loss. The discriminant network took the convolutional neural network and used the labels from the source domain, to distinguish whether the segmentation result of the generated network is from the source domain or the target domain. The whole training process was unsupervised. The proposed method was tested with experiments on a public dataset of knee magnetic resonance (MR) images and the clinical dataset from our cooperative hospital. With our method, the mean Dice similarity coefficient (DSC) of segmentation results increased by 2.52% and 6.10% to the classical feature level and image level domain adaptive method. The proposed method effectively improves the domain adaptive ability of the segmentation method, significantly improves the segmentation accuracy of the tibia and femur, and can better solve the domain transfer problem in MR image segmentation.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Joelho , Articulação do Joelho
7.
Int Orthop ; 42(3): 625-630, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29372269

RESUMO

PURPOSE: We investigated the incidence and pattern of traumatic fractures resulting from motor vehicle collisions in a population of children and adolescents (≤18 years old) and to determine the risk factors for nerve injury. METHODS: We retrospectively reviewed 734 patients admitted to our university-affiliated hospitals from 2001 to 2010. RESULTS: This study enrolled 498 male (67.8%) and 236 female (32.2%) patients aged 10.9 ± 5.3 years old. The most common injuries were to pedestrians, and the most common fracture sites (438, 59.7%) were to lower extremities (n = 441, 60.0%). A total of 201 (27.4%) patients experienced a nerve injury. Univariate logistic regression analysis showed that age (P = 0.014), lower-extremity (P = 0.000), craniofacial (P = 0.000) and spinal (P = 0.000) fractures were risk factors for nerve injury. Multivariate logistic regression analysis indicated that craniofacial [odds ratio (OR) = 9.003, 95% confidence interval (CI) 5.159-15.711, P = 0.000)] and spinal (experiencedOR = 10.141, 95% CI: 4.649-22.121, P = 0.011) fractures were independent risk factors for nerve injury. CONCLUSIONS: Patients in the 15- to 18-years old group and drivers had the largest sex ratio and highest frequencies of both nerve injury and early complications. Craniofacial and spinal fractures were independent risk factors for nerve injury. It is therefore important to focus on these risk factors to determine the presence of a nerve injury so that early, timely diagnosis and targeted treatment can be provided.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Fraturas Ósseas/epidemiologia , Traumatismos do Sistema Nervoso/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Feminino , Fraturas Ósseas/complicações , Humanos , Incidência , Masculino , Veículos Automotores , Estudos Retrospectivos , Fatores de Risco , Traumatismos do Sistema Nervoso/etiologia
8.
Sensors (Basel) ; 16(2): 228, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26891298

RESUMO

One of the main applications of mobile robots is the large-scale perception of the outdoor environment. One of the main challenges of this application is fusing environmental data obtained by multiple robots, especially heterogeneous robots. This paper proposes an enhanced iterative closest point (ICP) method for the fast and accurate registration of 3D environmental models. First, a hierarchical searching scheme is combined with the octree-based ICP algorithm. Second, an early-warning mechanism is used to perceive the local minimum problem. Third, a heuristic escape scheme based on sampled potential transformation vectors is used to avoid local minima and achieve optimal registration. Experiments involving one unmanned aerial vehicle and one unmanned surface vehicle were conducted to verify the proposed technique. The experimental results were compared with those of normal ICP registration algorithms to demonstrate the superior performance of the proposed method.

9.
J Spinal Disord Tech ; 28(1): E25-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25075987

RESUMO

STUDY DESIGN: A prospective study to access the significance of preoperative planning simulator for junior surgeons' training of pedicle screw insertion. SUMMARY OF BACKGROUND DATA: Pedicle screw insertion is particularly challenging to carry out on patients with abnormal spine morphology, especially for the doctors who lack experience. Currently, preoperative planning for pedicle screw insertion is carried out using patient computed tomography and magnetic resonance imaging scans. In addition, there is no projection fluoroscopy provided to the user. OBJECTIVE: The aim of this study was to investigate the feasibility and efficacy of a 3-dimensional, patient-specific volume rendering combined with the projection fluoroscopy simulator for training junior surgeons with no experience of pedicle screw insertion, and to help identify the role such simulation has in surgical education. METHODS: Two junior surgeons with no experience of pedicle screw insertion were trained on the technique through the preoperative planning simulator; the operative time and the position of the pedicle screws were assessed before training (control group 1) and after training (experimental group) and compared with 2 senior spine surgeons with >10 years' experience of pedicle screw insertion (control group 2). RESULTS: The time of per pedicle screw insertion was 43.5±3.9 seconds in control group 1, 31.6±2.9 seconds in control group 2, and 50.8±3.7 seconds in experimental group. The relative position of the screw to the pedicle was graded regarding pedicle breach (I, no breach; II, <2 mm; III, 2-4 mm; IV, >4 mm). The pedicle breach grading I and II was 20 pedicle screws (20/56, 35.7%) in control group 1, 54 pedicle screws (54/56, 96.4%) in control group 2, and 44 pedicle screws (44/56, 78.6%) in the experimental group. There were significant differences between control group 1 and experimental group in the time of per pedicle screw insertion (P<0.001) and the rate of pedicle breach grading I and II (P<0.001). There were significant differences between control group 2 and experimental group in the time of per pedicle screw insertion (P<0.001) and the rate of pedicle breach grading I and II (P=0.004). CONCLUSIONS: The simulator offers many helpful features to the surgeon with respect to the surgical trainee learning the basic technique of pedicle screw insertion, using free-hand technique or under the guiding of intraoperative fluoroscopy. The surgical skills of the junior surgeons can be significantly improved through the training of simulator.


Assuntos
Simulação por Computador , Procedimentos Ortopédicos/educação , Procedimentos Ortopédicos/métodos , Parafusos Pediculares , Cuidados Pré-Operatórios/educação , Cirurgiões/educação , Feminino , Fluoroscopia , Humanos , Masculino , Software , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/cirurgia , Tomografia Computadorizada por Raios X
10.
Front Neurosci ; 18: 1330634, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38595970

RESUMO

Introduction: The tendon-sheath actuated bending-tip system (TAB) has been widely applied to long-distance transmission scenes due to its high maneuverability, safety, and compliance, such as in exoskeleton robots, rescue robots, and surgical robots design. Due to the suitability of operation in a narrow or tortuous environment, TAB has demonstrated great application potential in the area of minimally invasive surgery. However, TAB involves highly non-linear behavior due to hysteresis, creepage, and non-linear friction existing on the tendon routing, which is an enormous challenge for accurate control. Methods: Considering the difficulties in the precise modeling of non-linearity friction, this paper proposes a novel fuzzy control scheme for the Euler-Lagrange dynamics model of TAB for achieving tracking performance and providing accurate friction compensation. Finally, the asymptotic stability of the closed-loop system is proved theoretically and the effectiveness of the controller is verified by numerical simulation carried out in MATLAB/Simulink. Results: The desired angle can be reached quickly within 3 s by adopting the proposed controller without overshoot or oscillation in Tracking Experiment, demonstrating the regulation performance of the proposed control scheme. The proposed method still achieves the desired trajectory rapidly and accurately without steady-state errors in Varying-friction Experiment. The angle errors generated by external disturbances are < 1 deg under the proposed controller, which returns to zero in 2 s in Anti-disturbance Experiment. In contrast, comparative controllers take more time to be steady and are accompanied by oscillating and residual errors in all experiments. Discussion: The proposed method is model-free control and has no strict requirement for the dynamics model and friction model. It is proved that advanced tracking performance and real-time response can be guaranteed under the presence of unknown bounded non-linear friction and time-varying non-linear dynamics.

11.
Bioengineering (Basel) ; 11(4)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38671807

RESUMO

The impairment of walking balance function seriously affects human health and will lead to a significantly increased risk of falling. It is important to assess and improve the walking balance of humans. However, existing evaluation methods for human walking balance are relatively subjective, and the selected metrics lack effectiveness and comprehensiveness. We present a method to construct a comprehensive evaluation index of human walking balance. We used it to generate personal and general indexes. We first pre-selected some preliminary metrics of walking balance based on theoretical analysis. Seven healthy subjects walked with exoskeleton interference on a treadmill at 1.25 m/s while their ground reaction force information and kinematic data were recorded. One subject with Charcot-Marie-Tooth walked at multiple speeds without the exoskeleton while the same data were collected. Then, we picked a number of effective evaluation metrics based on statistical analysis. We finally constructed the Walking Balance Index (WBI) by combining multiple metrics using principal component analysis. The WBI can distinguish walking balance among different subjects and gait conditions, which verifies the effectiveness of our method in evaluating human walking balance. This method can be used to evaluate and further improve the walking balance of humans in subsequent simulations and experiments.

12.
J Neural Eng ; 21(2)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38621377

RESUMO

Objective.Dopaminergic treatment is effective for Parkinson's disease (PD). Nevertheless, the conventional treatment assessment mainly focuses on human-administered behavior examination while the underlying functional improvements have not been well explored. This paper aims to investigate brain functional variations of PD patients after dopaminergic therapy.Approach.This paper proposed a dynamic brain network decomposition method and discovered brain hemodynamic sub-networks that well characterized the efficacy of dopaminergic treatment in PD. Firstly, a clinical walking procedure with functional near-infrared spectroscopy was developed, and brain activations during the procedure from fifty PD patients under the OFF and ON states (without and with dopaminergic medication) were captured. Then, dynamic brain networks were constructed with sliding-window analysis of phase lag index and integrated time-varying functional networks across all patients. Afterwards, an aggregated network decomposition algorithm was formulated based on aggregated effectiveness optimization of functional networks in spanning network topology and cross-validation network variations, and utilized to unveil effective brain hemodynamic sub-networks for PD patients. Further, dynamic sub-network features were constructed to characterize the brain flexibility and dynamics according to the temporal switching and activation variations of discovered sub-networks, and their correlations with differential treatment-induced gait alterations were analyzed.Results.The results demonstrated that PD patients exhibited significantly enhanced flexibility after dopaminergic therapy within a sub-network related to the improvement of motor functions. Other sub-networks were significantly correlated with trunk-related axial symptoms and exhibited no significant treatment-induced dynamic interactions.Significance.The proposed method promises a quantified and objective approach for dopaminergic treatment evaluation. Moreover, the findings suggest that the gait of PD patients comprises distinct motor domains, and the corresponding neural controls are selectively responsive to dopaminergic treatment.


Assuntos
Encéfalo , Doença de Parkinson , Humanos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/tratamento farmacológico , Masculino , Feminino , Encéfalo/fisiopatologia , Pessoa de Meia-Idade , Idoso , Hemodinâmica/fisiologia , Hemodinâmica/efeitos dos fármacos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Rede Nervosa/fisiopatologia , Rede Nervosa/efeitos dos fármacos , Dopaminérgicos/administração & dosagem , Caminhada/fisiologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-39012735

RESUMO

Pneumatic artificial muscle (PAM) has been widely used in rehabilitation and other fields as a flexible and safe actuator. In this paper, a PAM-actuated wearable exoskeleton robot is developed for upper limb rehabilitation. However, accurate modeling and control of the PAM are difficult due to complex hysteresis. To solve this problem, this paper proposes an active neural network method for hysteresis compensation, where a neural network (NN) is utilized as the hysteresis compensator and unscented Kalman filtering is used to estimate the weights and approximation error of the NN in real time. Compared with other inversion-based methods, the NN is directly used as the hysteresis compensator without needing inversion. Additionally, the proposed method does not require pre-training of the NN since the weights can be dynamically updated. To verify the effectiveness and robustness of the proposed method, a series of experiments have been conducted on the self-built exoskeleton robot. Compared with other popular control methods, the proposed method can track the desired trajectory faster, and tracking accuracy is gradually improved through iterative learning and updating.


Assuntos
Algoritmos , Exoesqueleto Energizado , Redes Neurais de Computação , Robótica , Extremidade Superior , Dispositivos Eletrônicos Vestíveis , Humanos , Robótica/instrumentação , Músculo Esquelético/fisiologia , Fenômenos Biomecânicos , Desenho de Equipamento
14.
Comput Biol Med ; 180: 108948, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39121681

RESUMO

PURPOSE: The technological advancements in surgical robots compatible with magnetic resonance imaging (MRI) have created an indispensable demand for real-time deformable image registration (DIR) of pre- and intra-operative MRI, but there is a lack of relevant methods. Challenges arise from dimensionality mismatch, resolution discrepancy, non-rigid deformation and requirement for real-time registration. METHODS: In this paper, we propose a real-time DIR framework called MatchMorph, specifically designed for the registration of low-resolution local intraoperative MRI and high-resolution global preoperative MRI. Firstly, a super-resolution network based on global inference is developed to enhance the resolution of intraoperative MRI to the same as preoperative MRI, thus resolving the resolution discrepancy. Secondly, a fast-matching algorithm is designed to identify the optimal position of the intraoperative MRI within the corresponding preoperative MRI to address the dimensionality mismatch. Further, a cross-attention-based dual-stream DIR network is constructed to manipulate the deformation between pre- and intra-operative MRI, real-timely. RESULTS: We conducted comprehensive experiments on publicly available datasets IXI and OASIS to evaluate the performance of the proposed MatchMorph framework. Compared to the state-of-the-art (SOTA) network TransMorph, the designed dual-stream DIR network of MatchMorph achieved superior performance with a 1.306 mm smaller HD and a 0.07 mm smaller ASD score on the IXI dataset. Furthermore, the MatchMorph framework demonstrates an inference speed of approximately 280 ms. CONCLUSIONS: The qualitative and quantitative registration results obtained from high-resolution global preoperative MRI and simulated low-resolution local intraoperative MRI validated the effectiveness and efficiency of the proposed MatchMorph framework.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Cirurgia Assistida por Computador , Humanos , Imageamento por Ressonância Magnética/métodos , Cirurgia Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos
15.
Artigo em Inglês | MEDLINE | ID: mdl-38231809

RESUMO

Neurovascular coupling (NVC) connects neural activity with hemodynamics and plays a vital role in sustaining brain function. Combining electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) is a promising way to explore the NVC. However, the high-order property of EEG data and variability of hemodynamic response function (HRF) across subjects have not been well considered in existing NVC studies. In this study, we proposed a novel framework to enhance the subject-specific parametric modeling of NVC from simultaneous EEG-fNIRS measurement. Specifically, task-related tensor decomposition of high-order EEG data was performed to extract the underlying connections in the temporal-spectral-spatial structures of EEG activities and identify the most relevant temporal signature within multiple trials. Subject-specific HRFs were estimated by parameters optimization of a double gamma function model. A canonical motor task experiment was designed to induce neural activity and validate the effectiveness of the proposed framework. The results indicated that the proposed framework significantly improves the reproducibility of EEG components and the correlation between the predicted hemodynamic activities and the real fNIRS signal. Moreover, the estimated parameters characterized the NVC differences in the task with two speeds. Therefore, the proposed framework provides a feasible solution for the quantitative assessment of the NVC function.


Assuntos
Acoplamento Neurovascular , Humanos , Acoplamento Neurovascular/fisiologia , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Eletroencefalografia/métodos , Hemodinâmica/fisiologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-38386574

RESUMO

Deep brain stimulation (DBS) is establishing itself as a promising treatment for disorders of consciousness (DOC). Measuring consciousness changes is crucial in the optimization of DBS therapy for DOC patients. However, conventional measures use subjective metrics that limit the investigations of treatment-induced neural improvements. The focus of this study is to analyze the regulatory effects of DBS and explain the regulatory mechanism at the brain functional level for DOC patients. Specifically, this paper proposed a dynamic brain temporal-spectral analysis method to quantify DBS-induced brain functional variations in DOC patients. Functional near-infrared spectroscopy (fNIRS) that promised to evaluate consciousness levels was used to monitor brain variations of DOC patients. Specifically, a fNIRS-based experimental procedure with auditory stimuli was developed, and the brain activities during the procedure from thirteen DOC patients before and after the DBS treatment were recorded. Then, dynamic brain functional networks were formulated with a sliding-window correlation analysis of phase lag index. Afterwards, with respect to the temporal variations of global and regional networks, the variability of global efficiency, local efficiency, and clustering coefficient were extracted. Further, dynamic networks were converted into spectral representations by graph Fourier transform, and graph energy and diversity were formulated to assess the spectral global and regional variability. The results showed that DOC patients under DBS treatment exhibited increased global and regional functional variability that was significantly associated with consciousness improvements. Moreover, the functional variability in the right brain regions had a stronger correlation with consciousness enhancements than that in the left brain regions. Therefore, the proposed method well signifies DBS-induced brain functional variations in DOC patients, and the functional variability may serve as promising biomarkers for consciousness evaluations in DOC patients.


Assuntos
Transtornos da Consciência , Estado de Consciência , Humanos , Transtornos da Consciência/terapia , Encéfalo
17.
J Neurosci Methods ; 402: 110031, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38040127

RESUMO

BACKGROUND: Early identification of mild cognitive impairment (MCI) is essential for its treatment and the prevention of dementia in Parkinson's disease (PD). Existing approaches are mostly based on neuropsychological assessments, while brain activation and connection have not been well considered. NEW METHOD: This paper presents a neuroimaging-based graph frequency analysis method and the generated features to quantify the brain functional neurodegeneration and distinguish between PD-MCI patients and healthy controls. The Stroop color-word experiment was conducted with 20 PD-MCI patients and 34 healthy controls, and the brain activation was recorded with functional near-infrared spectroscopy (fNIRS). Then, the functional brain network was constructed based on Pearson's correlation coefficient calculation between every two fNIRS channels. Next, the functional brain network was represented as a graph and decomposed in the graph frequency domain through the graph Fourier transform (GFT) to obtain the eigenvector matrix. Total variation and weighted zero crossings of eigenvectors were defined and integrated to quantify functional interaction between brain regions and the spatial variability of the brain network in specific graph frequency ranges, respectively. After that, the features were employed in training a support vector machine (SVM) classifier. RESULTS: The presented method achieved a classification accuracy of 0.833 and an F1 score of 0.877, significantly outperforming existing methods and features. COMPARISON WITH EXISTING METHODS: Our method provided improved classification performance in the identification of PD-MCI. CONCLUSION: The results suggest that the presented graph frequency analysis method well identify PD-MCI patients and the generated features promise functional brain biomarkers for PD-MCI diagnosis.


Assuntos
Disfunção Cognitiva , Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Disfunção Cognitiva/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Neuroimagem
18.
Artigo em Inglês | MEDLINE | ID: mdl-39186424

RESUMO

Dopaminergic treatment has proved effective to Parkinson's disease (PD), but the conventional treatment assessment is human-administered and prone to intra- and inter-assessor variability. In this paper, we propose a knowledge-driven framework and discover that brain ACtivation-Transition-Spectrum (ACTS) features achieve effective quantified assessments of dopaminergic therapy in PD. Firstly, brain activities of fifty-one PD patients during clinical walking tests under the OFF and ON states (without and with dopaminergic medication) were measured with functional near-infrared spectroscopy (fNIRS). Then, brain ACTS features were formulated based on the medication-induced variations in temporal features of brain regional activation, transition features of brain hemodynamic states, and graph spectrum of brain functional connectivity. Afterwards, a prior selection algorithm was constructed based on recursive feature elimination and graph spectrum analysis for the selection of principal discriminative features. Further, linear discriminant analysis was conducted to predict the treatment-induced improvements. The results demonstrated that the proposed method decreased the misclassification probability from 42% to 16% in the evaluations of dopaminergic treatment and outperformed existing fNIRS-based methods. Therefore, the proposed method promises a quantified and objective approach for dopaminergic treatment assessment, and our brain ACTS features may serve as promising functional biomarkers for treatment evaluation.


Assuntos
Algoritmos , Encéfalo , Doença de Parkinson , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/fisiopatologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Encéfalo/metabolismo , Análise Discriminante , Dopaminérgicos/uso terapêutico , Caminhada/fisiologia , Hemodinâmica
19.
Artigo em Inglês | MEDLINE | ID: mdl-38717735

RESUMO

Limosilactobacillus fermentum is an important member of the lactic acid bacteria group and holds immense potential for probiotic properties in human health and relevant industries. In this study, a comparative probiogenomic approach was applied to analyze the genome sequence of L. fermentum 3872, which was extracted from a commercially available yogurt sample, along with 20 different publicly available strains. Results indicate that the genome size of the characterized L. fermentum 3892 strain is 2,057,839 bp, with a single- and circular-type chromosome possessing a G + C content of 51.69%. The genome of L. fermentum 3892 strain comprises a total of 2120 open reading frames (ORFs), two genes encoding rRNAs, and 53 genes encoding tRNAs. Upon comparative probiogenomic analysis, two plasmid sequences were detected among the study strains, including one for the L. fermentum 3872 genome, which was found between position 1,288,203 and 1,289,237 with an identity of 80.98. The whole-genome alignment revealed 2223 identical sites and a pairwise identity of 98.9%, indicating a significant difference of 1.1% among genome strains. Comparison of amino acid encoding genes among strains included in this study suggests that the strain 3872 exhibited the highest degree of amino acids present, including glutamine, glutamate, aspartate, asparagine, lysine, threonine, methionine, and cysteine. The comparative antibiotic resistome profiling revealed that strain 3872 exhibited a high resistant capacity only to ciprofloxacin antibiotics as compared to other strains. This study provides a genomic-based evaluation approach for comparative probiotic strain analysis in commercial foods and their significance to human health.

20.
Front Bioeng Biotechnol ; 11: 1217918, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37823025

RESUMO

Introduction: Musculoskeletal model-based simulations have gained popularity as a tool for analyzing human movement biomechanics. However, when examining the same gait, different models with varying anatomical data and assumptions may produce inconsistent biomechanical results. This inconsistency is particularly relevant for children with cerebral palsy, who often exhibit multiple pathological gait patterns that can impact model outputs. Methods: The aim of this study was to investigate the effect of selecting musculoskeletal models on the biomechanical analysis results in children with cerebral palsy. Gait data were collected from multiple participants at slow, medium, and fast velocities. Joint kinematics, joint dynamics, and muscle activation were calculated using six popular musculoskeletal models within a biomechanical simulation environment. Results: The degree of inconsistency, measured as the root-mean-square deviation, in kinematic and kinetic results produced by the different models ranged from 4% to 40% joint motion range and 0%-28% joint moment range, respectively. The correlation between the results of the different models (both kinematic and kinetic) was good (R>0.85, P <0.01), with a stronger correlation observed in the kinetic results. Four of the six models showed a positive correlation between the simulated muscle activation of rectus femoris and the surface EMG, while all models exhibited a positive correlation between the activation of medial gastrocnemius and the surface EMG (P <0.01). Discussion: These results provide insights into the consistency of model results, factors influencing consistency, characteristics of each model's outputs, mechanisms underlying these characteristics, and feasible applications for each model. By elucidating the impact of model selection on biomechanical analysis outcomes, this study advances the field's understanding of musculoskeletal modeling and its implications for clinical gait analysis model decision-making in children with cerebral palsy.

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