individual model

  • 文章类型: Journal Article
    功能性电刺激(FES)是一种支持神经康复的既定方法。然而,尤其是前臂,它仍然不能引起形成复杂手部运动基础的选择性肌肉激活。在选择性肌肉激活的背景下的当前研究方法通常试图通过增加电极的数量并将它们组合在电极阵列中来实现靶向刺激。为了确定最佳的刺激位置和设置,使用手动或半自动算法。这种方法由于实验限制而受到限制。模拟研究的支持性使用已经确立,但是现有的模拟模型不适合分析由于缺失或任意排列的神经支配区而导致的选择性肌肉激活。
    这项研究引入了一种新的建模方法,以设计一个特定于人的数字双胞胎,该双胞胎能够预测前臂上FES期间的肌肉活动。设计的单个模型由三部分组成:基于解剖学的3D体积导体,不同感兴趣区域(ROI)中的肌肉特异性神经纤维排列,和标准神经模型.所有过程都嵌入在脚本或宏中,以实现对模型和仿真设置的自动更改。
    模拟强度-持续时间图的实验评估显示出良好的一致性。模拟振幅与四个实验的平均振幅的相对差异与实验间差异在相同的范围内,平均值在0.005和0.045之间。基于这些结果,确定肌肉特异性激活阈值并将其整合到模拟过程中.有了这个修改,模拟力-强度曲线与额外测量曲线吻合良好。
    结果表明,该模型适用于模拟逼真的肌肉特异性激活。由于复杂的手部动作是由个体生理组成的,选择性肌肉激活,可以假设该模型也适用于模拟这些运动。因此,这项研究提出了一种新的,非常有希望的方法,用于在感觉运动障碍的康复中开发新的应用和产品。
    UNASSIGNED: Functional electrical stimulation (FES) is an established method of supporting neurological rehabilitation. However, particularly on the forearm, it still cannot elicit selective muscle activations that form the basis of complex hand movements. Current research approaches in the context of selective muscle activation often attempt to enable targeted stimulation by increasing the number of electrodes and combining them in electrode arrays. In order to determine the best stimulation positions and settings, manual or semi-automated algorithms are used. This approach is limited due to experimental limitations. The supportive use of simulation studies is well-established, but existing simulation models are not suitable for analyses of selective muscle activation due to missing or arbitrarily arranged innervation zones.
    UNASSIGNED: This study introduces a new modeling method to design a person-specific digital twin that enables the prediction of muscle activations during FES on the forearm. The designed individual model consists of three parts: an anatomically based 3D volume conductor, a muscle-specific nerve fiber arrangement in various regions of interest (ROIs), and a standard nerve model. All processes were embedded in scripts or macros to enable automated changes to the model and the simulation setup.
    UNASSIGNED: The experimental evaluation of simulated strength-duration diagrams showed good coincidence. The relative differences of the simulated amplitudes to the mean amplitude of the four experiments were in the same range as the inter-experimental differences, with mean values between 0.005 and 0.045. Based on these results, muscle-specific activation thresholds were determined and integrated into the simulation process. With this modification, simulated force-intensity curves showed good agreement with additionally measured curves.
    UNASSIGNED: The results show that the model is suitable for simulating realistic muscle-specific activations. Since complex hand movements are physiologically composed of individual, selective muscle activations, it can be assumed that the model is also suitable for simulating these movements. Therefore, this study presents a new and very promising approach for developing new applications and products in the context of the rehabilitation of sensorimotor disorders.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    疲劳的个体生物数学模型(BMMF)是检测疲劳和可能事件的有前途的工具。现有的个体BMMF已经在实验室实验中得到验证,在该实验中,受试者经历完全睡眠剥夺(TSD)和常规慢性睡眠剥夺(CSD)。然而,一些轮班人群在现实生活中经历轻度睡眠剥夺(MSD)或不规则睡眠剥夺(ISD)。我们采用自适应动量估计算法来调整个人的经典SAFTE模型。当收集新的性能数据时,可以实时执行模型个性化。将单个SAFTE模型与TSD中现有的BMMF进行了比较,CSD,MSD,和ISD。验证结果表明,单个SAFTE模型在现实生活中从军官和卡车司机收集的MSD和ISD数据集中具有优势。这项研究扩展了先前关于BMMF实时个性化的研究结果,并将单个BMMF暴露于该领域的各种睡眠剥夺条件。从业者总结:这项研究提出了疲劳的个体生物数学模型,以预测人类在轻度和不规则睡眠剥夺中的表现。在实验室和现场的验证结果表明,在预测警察和卡车司机在现实生活中的表现时,所提出的模型比现有模型具有优势。
    Individual biomathematical models of fatigue (BMMF) are promising tools for detecting fatigue and possible incidents. Existing individual BMMFs have been validated in laboratory experiments in which subjects experience total sleep deprivation (TSD) and regular chronic sleep deprivation (CSD). However, some shift populations experience mild sleep deprivation (MSD) or irregular sleep deprivation (ISD) in real life. We employed the adaptive momentum estimation algorithm to adjust the classical SAFTE model for an individual. Model individualisation can be performed in real-time when new performance data are collected. The individual SAFTE model was compared with existing BMMFs in TSD, CSD, MSD, and ISD. The validation results show that the individual SAFTE model has advantages in MSD and ISD datasets collected from officers and truck drivers in real life. This study expands previous research results on the real-time individualisation of BMMFs and exposes individual BMMFs to various sleep-deprivation conditions in the field. Practitioner summary: This study proposes an individual biomathematical models of fatigue to predict human performance in mild and irregular sleep deprivation. The validation results in both laboratory and field show the proposed model has advantages over existing models when predicting officers\' and truck drivers\' performance in real life.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    In this present research, a spectroscopic method based on UV-Vis spectroscopy is utilized to quantify the level of corn adulteration in peaberry ground roasted coffee by chemometrics. Peaberry coffee with two types of bean processing of wet and dry-processed methods was used and intentionally adulterated by corn with a 10-50% level of adulteration. UV-Vis spectral data are obtained for aqueous samples in the range between 250 and 400 nm with a 1 nm interval. Three multivariate regression methods, including partial least squares regression (PLSR), multiple linear regression (MLR), and principal component regression (PCR), are used to predict the level of corn adulteration. The result shows that all individual regression models using individual wet and dry samples are better than that of global regression models using combined wet and dry samples. The best calibration model for individual wet and dry and combined samples is obtained for the PLSR model with a coefficient of determination in the range of 0.83-0.93 and RMSE below 6% (w/w) for calibration and validation. However, the error prediction in terms of RMSEP and bias were highly increased when the individual regression model was used to predict the level of corn adulteration with differences in the bean processing method. The obtained results demonstrate that the use of the global PLSR model is better in predicting the level of corn adulteration. The error prediction for this global model is acceptable with low RMSEP and bias for both individual and combined prediction samples. The obtained RPDp and RERp in prediction for the global PLSR model are more than two and five for individual and combined samples, respectively. The proposed method using UV-Vis spectroscopy with a global PLSR model can be applied to quantify the level of corn adulteration in peaberry ground roasted coffee with different bean processing methods.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    Mathematical models of sexually transmitted disease (STI) are increasingly relied on to inform policy, practice, and resource allocation. Because STI transmission requires sexual contact between two or more people, a model\'s ability to represent the dynamics of sexual partnerships can influence the validity of findings. This ability is to a large extent constrained by the model type, as different modeling frameworks vary in their capability to capture patterns of sexual contact at individual, partnership, and network levels. In this paper, we classify models into three groups: compartmental, individual-based, and statistical network models. For each framework, we describe the basic model structure and discuss key aspects of sexual partnership dynamics: how and with whom partnerships are formed, partnership duration and dissolution, and temporal overlap in partnerships (concurrency). We illustrate the potential implications of accurately accounting for partnership dynamics, but these effects depend on characteristics of both the population and pathogen; the combined impact of these partnership and epidemiologic dynamics can be difficult to predict. While each of the reviewed model frameworks may be appropriate to inform certain research or policy questions, modelers and consumers of models should carefully consider the implications of sexual partnership dynamics for the questions under study.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

  • 文章类型: Journal Article
    To release the strong dependence of the conventional inertial navigation mechanization on the a priori low-cost inertial measurement unit (IMU) error model, this research applies an unconventional multi-sensor integration strategy to integrate multiple low-cost IMUs and a global positioning system (GPS) for mass-market automotive applications. The unconventional integration strategy utilizes a basic three-dimensional (3D) kinematic trajectory model as the system model to directly estimate navigational parameters, and it allows the measurements from all of the sensors independently participating in measurement updates. However, the less complex kinematic model cannot realize smooth transitions between different motion statuses for the road vehicle with acceleration maneuvers. In this manuscript, we establish a more practical 3D kinematic trajectory model based on a \"current\" statistical Singer acceleration model to realize smooth transitions for the maneuvering vehicle. In addition, taking advantage of the unconventional strategy, we individually model the systematic errors of each IMU and the measurements of all sensors, in contrast to most existing approaches that adopt the common-mode errors for different sensors of the same design. A real dataset involving a GPS and multiple IMUs is processed to validate the success of the proposed algorithm model under the unconventional integration strategy.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

公众号