signal processing

信号处理
  • 文章类型: Journal Article
    背景:在人工耳蜗(CI)治疗中,结果有很大的可变性。我们研究的目的是确定与描述CI接受者结局特征的这种变异性最直接相关的独立听力测量。对选定的成年患者使用扩展的听力测量测试电池,以表征CI结果的全部范围。方法:根据术后结果招募CI使用者,将其分为三组:低(第1四分位数),中等(中小数),和高听力性能(第四四分位数)。通过使用(i)单音节单词(40-80dBSPL)在安静中测量语音识别,(ii)数字的语音接收阈值(SRT),和(Iii)德国矩阵噪声测试。为了在诊所重建苛刻的日常听力情况,背景噪声的时间特征和信号源的空间排列变化,以进行噪声测试。此外,使用演讲进行了一项调查,Spatial,和质量(SSQ)问卷和倾听努力(LE)问卷。结果:每组15名受试者(总N=45),在年龄方面没有显着差异,CI手术后的时间,orCI使用行为。两组主要在言语测听结果上有所不同。对于语音识别,在安静的单音节测试和静止(S0°N0°)和波动(S0°NCI)噪声中的句子之间,三组之间存在显着差异。安静中的单词理解和句子理解都与噪声中的SRT密切相关。该观察结果也通过因素分析得到证实。对于SSQ问卷和LE问卷结果,三组之间没有发现显着差异。因子分析的结果表明,噪声中的语音识别提供的信息与安静中语音清晰度的信息具有高度可比性。结论:因素分析强调了描述CI患者术后结局的三个组成部分。这些是(i)听力测量的超阈值语音识别和(ii)近阈值可听度,以及(iii)问卷调查确定的对与现实生活的关系的主观评估。这些参数似乎非常适合为测试电池建立框架以评估CI结果。
    Background: In cochlear implant (CI) treatment, there is a large variability in outcome. The aim of our study was to identify the independent audiometric measures that are most directly relevant for describing this variability in outcome characteristics of CI recipients. An extended audiometric test battery was used with selected adult patients in order to characterize the full range of CI outcomes. Methods: CI users were recruited for this study on the basis of their postoperative results and divided into three groups: low (1st quartile), moderate (medium decentile), and high hearing performance (4th quartile). Speech recognition was measured in quiet by using (i) monosyllabic words (40-80 dB SPL), (ii) speech reception threshold (SRT) for numbers, and (iii) the German matrix test in noise. In order to reconstruct demanding everyday listening situations in the clinic, the temporal characteristics of the background noise and the spatial arrangements of the signal sources were varied for tests in noise. In addition, a survey was conducted using the Speech, Spatial, and Qualities (SSQ) questionnaire and the Listening Effort (LE) questionnaire. Results: Fifteen subjects per group were examined (total N = 45), who did not differ significantly in terms of age, time after CI surgery, or CI use behavior. The groups differed mainly in the results of speech audiometry. For speech recognition, significant differences were found between the three groups for the monosyllabic tests in quiet and for the sentences in stationary (S0°N0°) and fluctuating (S0°NCI) noise. Word comprehension and sentence comprehension in quiet were both strongly correlated with the SRT in noise. This observation was also confirmed by a factor analysis. No significant differences were found between the three groups for the SSQ questionnaire and the LE questionnaire results. The results of the factor analysis indicate that speech recognition in noise provides information highly comparable to information from speech intelligibility in quiet. Conclusions: The factor analysis highlighted three components describing the postoperative outcome of CI patients. These were (i) the audiometrically measured supra-threshold speech recognition and (ii) near-threshold audibility, as well as (iii) the subjective assessment of the relationship to real life as determined by the questionnaires. These parameters appear well suited to setting up a framework for a test battery to assess CI outcomes.
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  • 文章类型: Journal Article
    使用激活MRI在认知任务期间确定视觉注意力仍然具有挑战性。这项研究旨在开发一种新的眼动追踪(ET)后处理平台,以提高数据准确性。验证后续ET-fMRI应用的可行性,并提供工具支持。16名年龄在18至20岁之间的志愿者暴露于视觉时间范式,在不同位置改变物体和面部的图像,同时使用与MRI兼容的ET系统记录他们的眼球运动。结果表明,后处理后数据的准确性明显提高。参与者通常在屏幕上保持视觉注意力,平均注视位置从89.1%到99.9%不等。在认知任务中,凝视的位置显示了对指令的坚持,平均值从46.2%到50%不等。时间一致性评估表明,长时间的视觉任务可能导致某些任务期间注意力下降。提出的方法有效地识别和量化的视觉伪影和损失,提供视觉注意力的精确测量。这项研究为未来的工作提供了一个强大的框架,将过滤的眼睛跟踪数据与fMRI分析相结合。支持认知神经科学研究。
    Determining visual attention during cognitive tasks using activation MRI remains challenging. This study aimed to develop a new eye-tracking (ET) post-processing platform to enhance data accuracy, validate the feasibility of subsequent ET-fMRI applications, and provide tool support. Sixteen volunteers aged 18 to 20 were exposed to a visual temporal paradigm with changing images of objects and faces in various locations while their eye movements were recorded using an MRI-compatible ET system. The results indicate that the accuracy of the data significantly improved after post-processing. Participants generally maintained their visual attention on the screen, with mean gaze positions ranging from 89.1% to 99.9%. In cognitive tasks, the gaze positions showed adherence to instructions, with means ranging from 46.2% to 50%. Temporal consistency assessments indicated prolonged visual tasks can lead to decreased attention during certain tasks. The proposed methodology effectively identified and quantified visual artifacts and losses, providing a precise measure of visual attention. This study offers a robust framework for future work integrating filtered eye-tracking data with fMRI analyses, supporting cognitive neuroscience research.
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  • 文章类型: Journal Article
    状态监测(CM)是预测和健康管理(PHM)的基础,这在工业界越来越重要。CM,这是指在操作过程中跟踪工业设备的健康状况,戏剧,事实上,在可靠性方面的重要作用,安全,和工业运营效率。本文提出了一种数据驱动的CM方法,该方法基于对采集的传感器数据进行自回归(AR)建模及其在频率子带内的分析。带的数量和大小是通过微不足道的人为干预来确定的,仅分析正常系统操作条件下感兴趣信号的时频表示。特别是,该方法利用同步压缩变换来改善信号在时频平面上的能量分布,定义基于AR功率谱密度和对称Itakura-Saito光谱距离的多维健康指标。所描述的健康指示器证明能够检测由于故障的发生而引起的信号频谱的变化。在初始定义频带和计算标称AR频谱的特性之后,该程序无需进一步干预,可用于在线状态监测和故障诊断。由于它是基于不同操作条件下的光谱比较,它的适用性既不取决于所获取信号的性质,也不取决于要监视的特定系统。作为一个例子,使用凯斯西储大学(CWRU)轴承数据中心的实际数据,一个广为人知和使用的基准。
    Condition monitoring (CM) is the basis of prognostics and health management (PHM), which is gaining more and more importance in the industrial world. CM, which refers to the tracking of industrial equipment\'s state of health during operations, plays, in fact, a significant role in the reliability, safety, and efficiency of industrial operations. This paper proposes a data-driven CM approach based on the autoregressive (AR) modeling of the acquired sensor data and their analysis within frequency subbands. The number and size of the bands are determined with negligible human intervention, analyzing only the time-frequency representation of the signal of interest under normal system operating conditions. In particular, the approach exploits the synchrosqueezing transform to improve the signal energy distribution in the time-frequency plane, defining a multidimensional health indicator built on the basis of the AR power spectral density and the symmetric Itakura-Saito spectral distance. The described health indicator proved capable of detecting changes in the signal spectrum due to the occurrence of faults. After the initial definition of the bands and the calculation of the characteristics of the nominal AR spectrum, the procedure requires no further intervention and can be used for online condition monitoring and fault diagnosis. Since it is based on the comparison of spectra under different operating conditions, its applicability depends neither on the nature of the acquired signal nor on a specific system to be monitored. As an example, the effectiveness of the proposed method was favorably tested using real data available in the Case Western Reserve University (CWRU) Bearing Data Center, a widely known and used benchmark.
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  • 文章类型: Journal Article
    本文提供的数据集是K.Edanami和G.Sun提供的名为“非接触式呼吸和心率测量的医疗雷达信号数据集”的数据集的更新[1]。新的数据集包括来自麻醉大鼠实验的雷达信号和参考激光测量值。大鼠被置于俯卧位,异氟烷以不同浓度给药以维持麻醉.将24GHz雷达和激光传感器放置在大鼠上方以捕获必要的数据。数据集包含带有时间戳的雷达I和Q通道信号以及激光测量。此外,提供了用于信号可视化和基于FFT(快速傅里叶变换)的呼吸速率估计的MATLAB代码。这个全面的数据集和随附的MATLAB代码促进了小动物非侵入性呼吸测量技术的进步,在生物医学研究中具有潜在的应用。
    The dataset presented in this article is an update of the dataset provided by K. Edanami and G. Sun entitled \"Medical Radar Signal Dataset for Non-Contact Respiration and Heart Rate Measurement\" [1]. The new dataset includes radar signals and reference laser measurements from experiments conducted on anesthetized rats. The rats were placed in a prone position, and isoflurane was administered in varying concentrations to maintain anesthesia. A 24 GHz radar and laser sensor were positioned above the rats to capture the necessary data. The dataset contains time-stamped radar I and Q channel signals as well as laser measurements. Additionally, MATLAB code for signal visualization and FFT (fast Fourier transform)-based respiration rate estimation is provided. This comprehensive dataset and accompanying MATLAB code facilitate the advancement of non-invasive respiration measurement techniques in small animals, with potential applications in biomedical research.
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  • 文章类型: Journal Article
    在临床耳蜗植入(CI)声音处理器上实施的常规信号处理基于从重叠频率区域提取的包络信号。常规策略不对具有高保真度的时间包络或时间精细结构线索进行编码。相比之下,最近已经开发了几种研究策略来增强时间包络和精细结构线索的编码。本研究研究了将时间包络线索编码为CI信号处理的声码器表示时的显著性。对听力正常的听众进行了语音接收的评估,语音质量评级,和空间听觉时,收听CI信号处理的声码器表示。与基于脉冲响应重构的新颖方法相比,评估了使用具有噪声或音调激励重构的包络信号的常规声码器技术。这种脉冲响应方法的一种变体是基于一种研究策略,根本异步刺激定时(FAST)算法,旨在提高包络线索的时间精度。结果表明,引入的脉冲响应方法,结合FAST算法,在语音接收措施上产生与传统声码器方法相似的结果,同时提供更好的音质和空间听觉结果。这种刺激时间包络线索如何编码到CI刺激的新颖方法有可能检查听力的各个方面,特别是在音乐音高感知和空间听觉方面。
    Conventional signal processing implemented on clinical cochlear implant (CI) sound processors is based on envelope signals extracted from overlapping frequency regions. Conventional strategies do not encode temporal envelope or temporal fine-structure cues with high fidelity. In contrast, several research strategies have been developed recently to enhance the encoding of temporal envelope and fine-structure cues. The present study examines the salience of temporal envelope cues when encoded into vocoder representations of CI signal processing. Normal-hearing listeners were evaluated on measures of speech reception, speech quality ratings, and spatial hearing when listening to vocoder representations of CI signal processing. Conventional vocoder techniques using envelope signals with noise- or tone-excited reconstruction were evaluated in comparison to a novel approach based on impulse-response reconstruction. A variation of this impulse-response approach was based on a research strategy, the Fundamentally Asynchronous Stimulus Timing (FAST) algorithm, designed to improve temporal precision of envelope cues. The results indicate that the introduced impulse-response approach, combined with the FAST algorithm, produces similar results on speech reception measures as the conventional vocoder approaches, while providing significantly better sound quality and spatial hearing outcomes. This novel approach for stimulating how temporal envelope cues are encoded into CI stimulation has potential for examining diverse aspects of hearing, particularly in aspects of musical pitch perception and spatial hearing.
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  • 文章类型: Journal Article
    大脑活动意味着相互关联的大脑区域的协调功能。典型的体外模型旨在使用单个人多能干细胞衍生的神经元网络来模拟大脑。然而,该领域正在不断发展,通过使用新的范式来更准确地模拟大脑功能,例如,具有分隔结构和集成传感器的芯片上大脑模型。这些方法创建了需要更复杂分析方法的新数据。先前引入的圆形三方网络概念对空间多样的神经元结构之间的连通性进行了建模。该模型由微流体装置组成,该装置允许具有嵌入式微电极阵列的分离的神经元网络之间的轴突连接,以记录闭合电路中的局部和全局电生理活动模式。现有工具对于使用该模型生成的数据的分析是次优的。这里,我们引入了用于同步和功能连接评估的高级工具。我们使用定制设计的分析来评估在KA之前和之后暴露于海藻酸(KA)的近端隔室与其未暴露的远端邻居之间的相互关系。与房间和房内功能连通性并行地检测和分析了新颖的多级电路突发模式。KA对近端隔室的影响被捕获,并揭示了这种效应向未暴露的远端隔室的传播。KA诱导了爆裂行为的发散变化,这可以通过不同的基线活动和不同的室内和室间连接强度来解释。圆形三方网络概念与我们开发的分析相结合,在体外对人类癫痫进行建模时,重要的是正面和构造有效性。
    Brain activity implies the orchestrated functioning of interconnected brain regions. Typical in vitro models aim to mimic the brain using single human pluripotent stem cell-derived neuronal networks. However, the field is constantly evolving to model brain functions more accurately through the use of new paradigms, e.g., brain-on-a-chip models with compartmentalized structures and integrated sensors. These methods create novel data requiring more complex analysis approaches. The previously introduced circular tripartite network concept models the connectivity between spatially diverse neuronal structures. The model consists of a microfluidic device allowing axonal connectivity between separated neuronal networks with an embedded microelectrode array to record both local and global electrophysiological activity patterns in the closed circuitry. The existing tools are suboptimal for the analysis of the data produced with this model. Here, we introduce advanced tools for synchronization and functional connectivity assessment. We used our custom-designed analysis to assess the interrelations between the kainic acid (KA)-exposed proximal compartment and its nonexposed distal neighbors before and after KA. Novel multilevel circuitry bursting patterns were detected and analyzed in parallel with the inter- and intracompartmental functional connectivity. The effect of KA on the proximal compartment was captured, and the spread of this effect to the nonexposed distal compartments was revealed. KA induced divergent changes in bursting behaviors, which may be explained by distinct baseline activity and varied intra- and intercompartmental connectivity strengths. The circular tripartite network concept combined with our developed analysis advances importantly both face and construct validity in modeling human epilepsy in vitro.
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  • 文章类型: Journal Article
    慢性脊柱疼痛(CSP)是一种普遍的疾病,长时间坐着工作可能会导致这种情况。像这样的人体工程学因素会导致运动变异性的变化。变异性分析是测量电机性能随时间变化的有用方法。当多次执行同一任务时,可以观察到不同的性能模式。这种可变性是所有生物系统固有的,并且在人类运动中很明显。这项研究旨在研究CSP是否会影响实时办公室工作中的运动变异性和复杂性。假设是,有疼痛和没有疼痛的个体对办公室工作任务的反应不同。六名没有疼痛的办公室工作人员和十名患有CSP的办公室工作人员参加了这项研究。参与者的躯干运动在工作期间记录了整整一周。躯干运动学位移的线性和非线性度量用于评估运动变异性和复杂性。混合方差分析用于比较两组之间运动变异性和复杂性的变化。效果表明,与患有CSP的参与者相比,无痛参与者表现出更复杂,更不可预测的躯干运动,结构和变异性程度较低。差异在精细运动中尤为明显。
    Chronic spinal pain (CSP) is a prevalent condition, and prolonged sitting at work can contribute to it. Ergonomic factors like this can cause changes in motor variability. Variability analysis is a useful method to measure changes in motor performance over time. When performing the same task multiple times, different performance patterns can be observed. This variability is intrinsic to all biological systems and is noticeable in human movement. This study aims to examine whether changes in movement variability and complexity during real-time office work are influenced by CSP. The hypothesis is that individuals with and without pain will have different responses to office work tasks. Six office workers without pain and ten with CSP participated in this study. Participant\'s trunk movements were recorded during work for an entire week. Linear and nonlinear measures of trunk kinematic displacement were used to assess movement variability and complexity. A mixed ANOVA was utilized to compare changes in movement variability and complexity between the two groups. The effects indicate that pain-free participants showed more complex and less predictable trunk movements with a lower degree of structure and variability when compared to the participants suffering from CSP. The differences were particularly noticeable in fine movements.
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  • 文章类型: Journal Article
    目标:调查有助于有效管理年龄相关性听力损失(ARHL)康复的因素。方法:遵循PRISMA指南进行系统评价。该方案在PROSPERO(CRD42022374811)中注册。文章是通过Scopus的系统搜索确定的,PubMed,WebofScience,以及2024年5月的Cochrane数据库。仅包括2005年1月至2024年5月之间发表的文章。由两名独立研究人员评估研究的资格,并使用Crowe关键评估工具v1.4(CCAT)进行评估。结果:在确定的278篇文章中,54人被包括在内。三个因素解释了HA的有效使用。首先,助听器信号处理,具有定向麦克风和降噪功能,提高了用户的舒适度和对噪声的理解。第二,有助听器配件,以NAL处方规则为黄金标准,和双边,用于空间定位和噪声理解的高级HA性能。第三,有一种以病人为中心的方法,使用患者相关结果测量(PROM),问卷,咨询,并定期随访,让患者参与治疗康复。结论:由于听力学结果的可变性,在声学参数上达成共识具有挑战性。让病人参与康复,满足他们的需求和期望,提供个性化护理至关重要。
    Objectives: Investigate factors contributing to the effective management of age-related hearing loss (ARHL) rehabilitation. Methods: A systematic review was conducted following PRISMA guidelines. The protocol was registered in PROSPERO (CRD42022374811). Articles were identified through systematic searches in the Scopus, PubMed, Web of Science, and Cochrane databases in May 2024. Only articles published between January 2005 and May 2024 were included. Studies were assessed for eligibility by two independent researchers and evaluated using the Crowe Critical Appraisal Tool v1.4 (CCAT). Results: Of the 278 articles identified, 54 were included. Three factors explain effective HA use. First, hearing aid signal processing, with directional microphones and noise reduction, improves user comfort and understanding regarding noise. Second, there is hearing aid fitting, with the NAL prescription rules as the gold standard, and bilateral, high-level HA performance for spatial localization and noise comprehension. Third, there is a patient-centered approach, using patient-related outcome measures (PROMs), questionnaires, counseling, and regular follow-up to involve patients in their therapeutic rehabilitation. Conclusions: Reaching a consensus on acoustic parameters is challenging due to variability in audiological results. Involving patients in their rehabilitation, addressing their needs and expectations, and offering individualized care are crucial.
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  • 文章类型: Journal Article
    阿尔茨海默病和相关疾病(ADRD)逐渐损害认知功能,促使需要早期检测以减轻其影响。轻度认知障碍(MCI)可能是ADRD导致的早期认知能力下降的信号。因此,开发一个可访问的,检测MCI的非侵入性方法对于启动早期干预措施以防止严重的认知恶化至关重要。
    本研究探讨了分析步态模式的效用,人类运动行为的一个基本方面,在诊断MCI的直线和椭圆形路径上。使用Kinectv.2摄像机,我们记录了25例MCI患者和30例健康老年人(HC)的25个身体关节的运动情况.信号处理,描述性统计分析,和机器学习技术被用来分析两种行走条件下的骨骼步态数据。
    研究表明,直线和椭圆形步行模式都为MCI检测提供了有价值的见解,在更复杂的椭圆形步行测试中,可识别的步态特征显着增加。随机森林模型在各种算法中表现出色,在椭圆形步行测试中检测MCI的准确率为85.50%,F评分为83.9%。这项研究引入了一种具有成本效益的,基于Kinect的方法,将步态分析-一种关键的行为模式-与机器学习集成在一起,为临床和家庭环境中的MCI筛查提供实用工具。
    UNASSIGNED: Alzheimer\'s disease and related disorders (ADRD) progressively impair cognitive function, prompting the need for early detection to mitigate its impact. Mild Cognitive Impairment (MCI) may signal an early cognitive decline due to ADRD. Thus, developing an accessible, non-invasive method for detecting MCI is vital for initiating early interventions to prevent severe cognitive deterioration.
    UNASSIGNED: This study explores the utility of analyzing gait patterns, a fundamental aspect of human motor behavior, on straight and oval paths for diagnosing MCI. Using a Kinect v.2 camera, we recorded the movements of 25 body joints from 25 individuals with MCI and 30 healthy older adults (HC). Signal processing, descriptive statistical analysis, and machine learning techniques were employed to analyze the skeletal gait data in both walking conditions.
    UNASSIGNED: The study demonstrated that both straight and oval walking patterns provide valuable insights for MCI detection, with a notable increase in identifiable gait features in the more complex oval walking test. The Random Forest model excelled among various algorithms, achieving an 85.50% accuracy and an 83.9% F-score in detecting MCI during oval walking tests. This research introduces a cost-effective, Kinect-based method that integrates gait analysis-a key behavioral pattern-with machine learning, offering a practical tool for MCI screening in both clinical and home environments.
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  • 文章类型: Journal Article
    目标:本文介绍了DISPEL,一个Python框架,以促进在神经退行性疾病的治疗开发背景下,从数字健康技术收集的数据中开发传感器衍生度量(SDM)。方法:模块化,采用面向对象的体系结构进行数据建模和SDM提取,实现了可集成性和灵活性,这也允许标准化SDM生成,命名,storage,和文档。此外,设计了一种功能来实现对缺失数据和意外用户行为的系统标记,两者都经常在无人监督的监测中。结果:DISPEL在MIT许可下可用。它已经支持来自不同数据提供商的格式,并允许从使用可穿戴设备和智能手机收集的原始数据到结构化SDM数据集进行可追溯的端到端处理。新的和基于文献的信号处理方法目前允许从16个结构化测试(包括六个问卷)中提取SDM,评估总体残疾和生活质量,并测量认知的表现结果,手动灵巧,和流动性。结论:DISPEL通过提供生产级Python框架和大量已实施的SDM来支持临床试验的SDM开发。尽管该框架已经根据临床试验数据进行了改进,建议用户在特定使用环境中对所提供的算法进行特别验证。
    Goal: This paper introduces DISPEL, a Python framework to facilitate development of sensor-derived measures (SDMs) from data collected with digital health technologies in the context of therapeutic development for neurodegenerative diseases. Methods: Modularity, integrability and flexibility were achieved adopting an object-oriented architecture for data modelling and SDM extraction, which also allowed standardizing SDM generation, naming, storage, and documentation. Additionally, a functionality was designed to implement systematic flagging of missing data and unexpected user behaviors, both frequent in unsupervised monitoring. Results: DISPEL is available under MIT license. It already supports formats from different data providers and allows traceable end-to-end processing from raw data collected with wearables and smartphones to structured SDM datasets. Novel and literature-based signal processing approaches currently allow to extract SDMs from 16 structured tests (including six questionnaires), assessing overall disability and quality of life, and measuring performance outcomes of cognition, manual dexterity, and mobility. Conclusion: DISPEL supports SDM development for clinical trials by providing a production-grade Python framework and a large set of already implemented SDMs. While the framework has already been refined based on clinical trials\' data, ad-hoc validation of the provided algorithms in their specific context of use is recommended to the users.
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