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1.
Crit Care ; 28(1): 105, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566212

RESUMO

BACKGROUND: Observational data suggest that the subset of patients with heart failure related CS (HF-CS) now predominate critical care admissions for CS. There are no dedicated HF-CS randomised control trials completed to date which reliably inform clinical practice or clinical guidelines. We sought to identify aspects of HF-CS care where both consensus and uncertainty may exist to guide clinical practice and future clinical trial design, with a specific focus on HF-CS due to acute decompensated chronic HF. METHODS: A 16-person multi-disciplinary panel comprising of international experts was assembled. A modified RAND/University of California, Los Angeles, appropriateness methodology was used. A survey comprising of 34 statements was completed. Participants anonymously rated the appropriateness of each statement on a scale of 1 to 9 (1-3 as inappropriate, 4-6 as uncertain and as 7-9 appropriate). RESULTS: Of the 34 statements, 20 were rated as appropriate and 14 were rated as inappropriate. Uncertainty existed across all three domains: the initial assessment and management of HF-CS; escalation to temporary Mechanical Circulatory Support (tMCS); and weaning from tMCS in HF-CS. Significant disagreement between experts (deemed present when the disagreement index exceeded 1) was only identified when deliberating the utility of thoracic ultrasound in the immediate management of HF-CS. CONCLUSION: This study has highlighted several areas of practice where large-scale prospective registries and clinical trials in the HF-CS population are urgently needed to reliably inform clinical practice and the synthesis of future societal HF-CS guidelines.


Assuntos
Insuficiência Cardíaca , Choque Cardiogênico , Humanos , Consenso , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/terapia , Hospitalização , Estudos Prospectivos , Choque Cardiogênico/tratamento farmacológico
2.
J Med Libr Assoc ; 111(1-2): 625-629, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37312806

RESUMO

"MAN PUT HIS TONGUE AGAINST REFRIGERATOR PIPE AND GOT IT FROZEN; HAVE THAWED IT OUT AND IT IS NOW BLISTERED AND SWOLLEN BUT NOT PAINFUL. ARRIVING HONOLULU FRIDAY; HOW CAN I HELP HIM MEANWHILE?" Thus read a message relayed via radiogram across the ocean to the physician stationed at the Seamen's Church Institute's (SCI) KDKF radio station, established by the Institute in 1920 on top of its thirteen-story seafarer services center at the southern tip of Manhattan. Though radio was in its infancy, radio telegraphy had already proven its revolutionary power, featuring prominently in far more serious maritime emergencies such as the sinking of Titanic. SCI's KDKF radio station aimed to address a less dramatic but no less important problem in blue water navigation: access to medical care.


Assuntos
Academias e Institutos , Médicos , Humanos , Dor
3.
Sensors (Basel) ; 20(16)2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32824156

RESUMO

Estimating depth from a single image is a challenging problem, but it is also interesting due to the large amount of applications, such as underwater image dehazing. In this paper, a new perspective is provided; by taking advantage of the underwater haze that may provide a strong cue to the depth of the scene, a neural network can be used to estimate it. Using this approach the depthmap can be used in a dehazing method to enhance the image and recover original colors, offering a better input to image recognition algorithms and, thus, improving the robot performance during vision-based tasks such as object detection and characterization of the seafloor. Experiments are conducted on different datasets that cover a wide variety of textures and conditions, while using a dense stereo depthmap as ground truth for training, validation and testing. The results show that the neural network outperforms other alternatives, such as the dark channel prior methods and it is able to accurately estimate depth from a single image after a training stage with depth information.

4.
J Acoust Soc Am ; 146(6): 4687, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31893715

RESUMO

When a broadband source of radiated noise transits past a fixed hydrophone, a Lloyd's mirror constructive/destructive interference pattern can be observed in the output spectrogram. By taking the spectrum of a (log) spectrum, the power cepstrum detects the periodic structure of the Lloyd's mirror fringe pattern by generating a sequence of pulses located at the fundamental quefrency and its multiples. The fundamental quefrency, which is the reciprocal of the frequency difference between adjacent destructive interference fringes, equates to the multipath delay time. An experiment is conducted where a motorboat transits past a hydrophone located about 1 m above the seafloor in very shallow water (20 m deep). The hydrophone has a frequency bandwidth of 90 kHz, and its output is sampled at 250 kHz. A cepstrogram database is compiled from multiple vessel transits, and its cepstrum-based feature vectors (along with ground-truth range data) form the input to train a convolutional neural network (CNN) so that it can predict the source range relative to the hydrophone for other ("unseen") vessel transits. The CNN provides an accurate prediction of the instantaneous source range even when the range estimate from conventional multipath passive ranging is biased, which occurs at low grazing angles (<12°).


Assuntos
Redes Neurais de Computação , Ruído , Valor Preditivo dos Testes , Água , Acústica , Localização de Som
5.
Pract Neurol ; 17(1): 47-50, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27895189

RESUMO

For many neurologists, lumbar puncture is the only practical procedure that they undertake on a regular basis. Although anaesthetists and emergency physicians routinely employ ultrasound to assist lumbar puncture, neurologists do not. In this article, we outline the technique that we use for an ultrasound-assisted lumbar puncture, together with the evidence base that suggests that ultrasound has significant benefits. We aim to raise awareness of a method that can make lumbar puncture more likely to succeed and to be more comfortable for the patient.


Assuntos
Testes Imediatos , Punção Espinal/métodos , Ultrassonografia de Intervenção/métodos , Humanos , Punção Espinal/instrumentação , Ultrassonografia de Intervenção/instrumentação
6.
Glob Chang Biol ; 22(5): 1965-75, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26679689

RESUMO

Habitat structural complexity is a key factor shaping marine communities. However, accurate methods for quantifying structural complexity underwater are currently lacking. Loss of structural complexity is linked to ecosystem declines in biodiversity and resilience. We developed new methods using underwater stereo-imagery spanning 4 years (2010-2013) to reconstruct 3D models of coral reef areas and quantified both structural complexity at two spatial resolutions (2.5 and 25 cm) and benthic community composition to characterize changes after an unprecedented thermal anomaly on the west coast of Australia in 2011. Structural complexity increased at both resolutions in quadrats (4 m(2)) that bleached, but not those that did not bleach. Changes in complexity were driven by species-specific responses to warming, highlighting the importance of identifying small-scale dynamics to disentangle ecological responses to disturbance. We demonstrate an effective, repeatable method for quantifying the relationship among community composition, structural complexity and ocean warming, improving predictions of the response of marine ecosystems to environmental change.


Assuntos
Organismos Aquáticos/fisiologia , Biodiversidade , Mudança Climática , Recifes de Corais , Temperatura Alta/efeitos adversos , Modelos Teóricos , Estações do Ano , Especificidade da Espécie , Austrália Ocidental
7.
Clin Immunol ; 160(2): 226-36, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26071317

RESUMO

Diversification of autoimmunity to islet autoantigens is critical for progression to Type 1 diabetes. B-cells participate in diversification by modifying antigen processing, thereby influencing which peptides are presented to T-cells. In Type 1 diabetes, JM antibodies are associated with T-cell responses to PTP domain peptides. We investigated whether this is the consequence of close structural alignment of JM and PTP domain determinants on IA-2. Fab fragments of IA-2 antibodies with epitopes mapped to the JM domain blocked IA-2 binding of antibodies that recognise epitopes in the IA-2 PTP domain. Peptides from both the JM and PTP domains were protected from degradation during proteolysis of JM antibody:IA-2 complexes and included those representing major T-cell determinants in Type 1 diabetes. The results demonstrate close structural relationships between JM and PTP domain epitopes on IA-2. Stabilisation of PTP domain peptides during proteolysis in JM-specific B-cells may explain determinant spreading in IA-2 autoimmunity.


Assuntos
Autoanticorpos/imunologia , Linfócitos B/imunologia , Diabetes Mellitus Tipo 1/imunologia , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Sequência de Aminoácidos , Autoantígenos/imunologia , Autoimunidade/imunologia , Criança , Epitopos/imunologia , Humanos , Adulto Jovem
8.
J Parkinsons Dis ; 13(4): 525-536, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37092233

RESUMO

BACKGROUND: Bradykinesia is considered the fundamental motor feature of Parkinson's disease (PD). It is central to diagnosis, monitoring, and research outcomes. However, as a clinical sign determined purely by visual judgement, the reliability of humans to detect and measure bradykinesia remains unclear. OBJECTIVE: To establish interrater reliability for expert neurologists assessing bradykinesia during the finger tapping test, without cues from additional examination or history. METHODS: 21 movement disorder neurologists rated finger tapping bradykinesia, by Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and Modified Bradykinesia Rating Scale (MBRS), in 133 videos of hands: 73 from 39 people with idiopathic PD, 60 from 30 healthy controls. Each neurologist rated 30 randomly-selected videos. 19 neurologists were also asked to judge whether the hand was PD or control. We calculated intraclass correlation coefficients (ICC) for absolute agreement and consistency of MDS-UPDRS ratings, using standard linear and cumulative linked mixed models. RESULTS: There was only moderate agreement for finger tapping MDS-UPDRS between neurologists, ICC 0.53 (standard linear model) and 0.65 (cumulative linked mixed model). Among control videos, 53% were rated > 0 by MDS-UPDRS, and 24% were rated as bradykinesia by MBRS subscore combination. Neurologists correctly identified PD/control status in 70% of videos, without strictly following bradykinesia presence/absence. CONCLUSION: Even experts show considerable disagreement about the level of bradykinesia on finger tapping, and frequently see bradykinesia in the hands of those without neurological disease. Bradykinesia is to some extent a phenomenon in the eye of the clinician rather than simply the hand of the person with PD.


Assuntos
Hipocinesia , Doença de Parkinson , Humanos , Dedos , Mãos , Hipocinesia/diagnóstico , Hipocinesia/etiologia , Movimento , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico , Reprodutibilidade dos Testes , Estudos de Casos e Controles
9.
Soc Neurosci ; 18(3): 142-154, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37267049

RESUMO

Socio-emotional interactions are integral for regulating emotions and buffering psychological distress. Social neuroscience perspectives on aging suggest that empathetic interpersonal interactions are supported by the activation of brain regions involved in regulating negative affect. The current study tested whether resting state functional connectivity of a network of brain regions activated during cognitive emotion regulation, i.e., emotion regulation network (ERN), statistically mediates the frequency of social contact with friends or family on psychological distress. Here, a 10-min resting-state functional MRI scan was collected along with self-reported anxiety/depressive, somatic, and thought problems and social networking from 90 community-dwelling older adults (aged 65-85 years). The frequency of social interactions with family, but not friends and neighbors, was associated with lower psychological distress. The magnitude of this effect was reduced by 33.34% to non-significant upon adding resting state ERN connectivity as a mediator. Follow-up whole-brain graph network analyses revealed that efficiency and centrality of the left inferior frontal gyrus and the right middle temporal gyrus relate to greater family interactions and lower distress. These hubs may help to buffer psychological problems in older adults through interactions involving empathetic and cognitive emotion regulation with close family.


Assuntos
Regulação Emocional , Angústia Psicológica , Humanos , Idoso , Encéfalo/diagnóstico por imagem , Emoções/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética
10.
IEEE Trans Pattern Anal Mach Intell ; 45(1): 593-607, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34982674

RESUMO

We describe a novel semi-supervised learning method that reduces the labelling effort needed to train convolutional neural networks (CNNs) when processing georeferenced imagery. This allows deep learning CNNs to be trained on a per-dataset basis, which is useful in domains where there is limited learning transferability across datasets. The method identifies representative subsets of images from an unlabelled dataset based on the latent representation of a location guided autoencoder. We assess the method's sensitivities to design options using four different ground-truthed datasets of georeferenced environmental monitoring images, where these include various scenes in aerial and seafloor imagery. Efficiency gains are achieved for all the aerial and seafloor image datasets analysed in our experiments, demonstrating the benefit of the method across application domains. Compared to CNNs of the same architecture trained using conventional transfer and active learning, the method achieves equivalent accuracy with an order of magnitude fewer annotations, and 85 % of the accuracy of CNNs trained conventionally with approximately 10,000 human annotations using just 40 prioritised annotations. The biggest gains in efficiency are seen in datasets with unbalanced class distributions and rare classes that have a relatively small number of observations.

11.
Br J Health Psychol ; 28(2): 604-618, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36626907

RESUMO

OBJECTIVES: Uncertainty regarding the legitimacy of functional neurological disorder (FND) remains among some health care professionals. Despite treatment guidelines and consensus recommendations, variability in clinical practice referral decisions persists. Evidence from other conditions suggests such clinical decision making is impacted by practitioners' implicit and explicit attitudes. We aimed to identify whether health care professionals hold implicit and/or explicit attitudes about the legitimacy of FND and whether these attitudes are associated with referral decision making. DESIGN/METHODS: We included 66 health care professionals who work with people with neurological conditions: n = 37 medical doctors, mainly neurologists (n = 18) and psychiatrists (n = 10), and n = 29 doctoral level practitioner psychologists. Participants completed an Implicit Association Test (IAT), Implicit Relational Assessment Procedure (IRAP), a referral decision-making vignette task and self-report measures of explicit attitudes on FND-legitimacy, therapeutic optimism and clinician confidence. Multiple Sclerosis (MS) was used as a comparator condition. RESULTS: Participants self-reported strong explicit FND-legitimate and MS-legitimate attitudes but demonstrated an implicit FND-illegitimate/MS-legitimate bias. Deeper examination provided by the IRAP data indicated pro-FND-legitimate attitudes, but no bias for or against FND-illegitimate-contrasting the pro-MS-legitimate, anti-MS-illegitimate attitudes for the comparator condition. Attitudes about FND-illegitimacy were negatively associated with likelihood of referral to physical interventions such as physiotherapy. Medical doctors had lower treatment optimism and stronger explicit attitudes that FND is illegitimate than psychologists. CONCLUSIONS: At an implicit level, clinicians are uncertain about the illegitimacy of FND, and such attitudes are associated with lower likelihood of referral to physiotherapy in particular. Improved education on FND among health care professionals is indicated.


Assuntos
Transtorno Conversivo , Médicos , Humanos , Atitude , Pessoal de Saúde , Autorrelato
12.
Artigo em Inglês | MEDLINE | ID: mdl-38083026

RESUMO

Background - Physiological tremor is defined as an involuntary and rhythmic shaking. Tremor of the hand is a key symptom of multiple neurological diseases, and its frequency and amplitude differs according to both disease type and disease progression. In routine clinical practice, tremor frequency and amplitude are assessed by expert rating using a 0 to 4 integer scale. Such ratings are subjective and have poor inter-rater reliability. There is thus a clinical need for a practical and accurate method for objectively assessing hand tremor.Objective - to develop a proof-of-principle method to measure hand tremor amplitude from smartphone videos.Methods - We created a computer vision pipeline that automatically extracts salient points on the hand and produces a 1-D time series of movement due to tremor, in pixels. Using the smartphones' depth measurement, we convert this measure into real distance units. We assessed the accuracy of the method using 60 videos of simulated tremor of different amplitudes from two healthy adults. Videos were taken at distances of 50, 75 and 100 cm between hand and camera. The participants had skin tone II and VI on the Fitzpatrick scale. We compared our method to a gold-standard measurement from a slide rule. Bland-Altman methods agreement analysis indicated a bias of 0.04 cm and 95% limits of agreement from -1.27 to 1.20 cm. Furthermore, we qualitatively observed that the method was robust to limited occlusion.Clinical relevance - We have demonstrated how tremor amplitude can be measured from smartphone videos. In conjunction with tremor frequency, this approach could be used to help diagnose and monitor neurological diseases.


Assuntos
Tremor Essencial , Tremor , Adulto , Humanos , Tremor/diagnóstico , Smartphone , Reprodutibilidade dos Testes , Projetos Piloto
13.
Nat Hum Behav ; 7(12): 2099-2110, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37904020

RESUMO

The extent to which languages share properties reflecting the non-linguistic constraints of the speakers who speak them is key to the debate regarding the relationship between language and cognition. A critical case is spatial communication, where it has been argued that semantic universals should exist, if anywhere. Here, using an experimental paradigm able to separate variation within a language from variation between languages, we tested the use of spatial demonstratives-the most fundamental and frequent spatial terms across languages. In n = 874 speakers across 29 languages, we show that speakers of all tested languages use spatial demonstratives as a function of being able to reach or act on an object being referred to. In some languages, the position of the addressee is also relevant in selecting between demonstrative forms. Commonalities and differences across languages in spatial communication can be understood in terms of universal constraints on action shaping spatial language and cognition.


Assuntos
Idioma , Semântica , Humanos , Cognição
14.
Comput Biol Med ; 147: 105776, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35780600

RESUMO

BACKGROUND: Telemedicine video consultations are rapidly increasing globally, accelerated by the COVID-19 pandemic. This presents opportunities to use computer vision technologies to augment clinician visual judgement because video cameras are so ubiquitous in personal devices and new techniques, such as DeepLabCut (DLC) can precisely measure human movement from smartphone videos. However, the accuracy of DLC to track human movements in videos obtained from laptop cameras, which have a much lower FPS, has never been investigated; this is a critical gap because patients use laptops for most telemedicine consultations. OBJECTIVES: To determine the validity and reliability of DLC applied to laptop videos to measure finger tapping, a validated test of human movement. METHOD: Sixteen adults completed finger-tapping tests at 0.5 Hz, 1 Hz, 2 Hz, 3 Hz and at maximal speed. Hand movements were recorded simultaneously by a laptop camera at 30 frames per second (FPS) and by Optotrak, a 3D motion analysis system at 250 FPS. Eight DLC neural network architectures (ResNet50, ResNet101, ResNet152, MobileNetV1, MobileNetV2, EfficientNetB0, EfficientNetB3, EfficientNetB6) were applied to the laptop video and extracted movement features were compared to the ground truth Optotrak motion tracking. RESULTS: Over 96% (529/552) of DLC measures were within +/-0.5 Hz of the Optotrak measures. At tapping frequencies >4 Hz, there was progressive decline in accuracy, attributed to motion blur associated with the laptop camera's low FPS. Computer vision methods hold potential for moving us towards intelligent telemedicine by providing human movement analysis during consultations. However, further developments are required to accurately measure the fastest movements.


Assuntos
COVID-19 , Telemedicina , Adulto , Computadores , Humanos , Movimento , Pandemias , Reprodutibilidade dos Testes
15.
J Neurol Sci ; 437: 120251, 2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35429701

RESUMO

BACKGROUND AND OBJECTIVES: Studies of Functional Neurological Disorders (FND) are usually outpatient-based. To inform service development, we aimed to describe patient pathways through healthcare events, and factors affecting risk of emergency department (ED) reattendance, for people presenting acutely with FND. METHODS: Acute neurology/stroke teams at a UK city hospital were contacted regularly over 8 months to log FND referrals. Electronic documentation was then reviewed for hospital healthcare events over the preceding 8 years. Patient pathways through healthcare events over time were mapped, and mixed effects logistic regression was performed for risk of ED reattendance within 1 year. RESULTS: In 8 months, 212 patients presented acutely with an initial referral suggesting FND. 20% had subsequent alternative diagnoses, but 162 patients were classified from documentation review as possible (17%), probable (28%) or definite (55%) FND. In the preceding 8 years, these 162 patients had 563 ED attendances and 1693 inpatient nights with functional symptoms, but only 26% were referred for psychological therapy, only 66% had a documented diagnosis, and care pathways looped around ED. Three better practice pathway steps were each associated with lower risk of subsequent ED reattendance: documented FND diagnosis (OR = 0.32, p = 0.004), referral to clinical psychology (OR = 0.35, p = 0.04) and outpatient neurology follow-up (OR = 0.25, p < 0.001). CONCLUSION: People that present acutely to a UK city hospital with FND tend to follow looping pathways through hospital healthcare events, centred around ED, with low rates of documented diagnosis and referral for psychological therapy. When better practice occurs, it is associated with lower risk of ED reattendance.


Assuntos
Transtorno Conversivo , Doenças do Sistema Nervoso , Doença Aguda , Atenção à Saúde , Serviço Hospitalar de Emergência , Humanos , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/epidemiologia , Doenças do Sistema Nervoso/terapia , Encaminhamento e Consulta
16.
Mov Disord Clin Pract ; 8(1): 69-75, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34853806

RESUMO

BACKGROUND: Computer vision can measure movement from video without the time and access limitations of hospital accelerometry/electromyography or the requirement to hold or strap a smartphone accelerometer. OBJECTIVE: To compare computer vision measurement of hand tremor frequency from smartphone video with a gold standard measure accelerometer. METHODS: A total of 37 smartphone videos of hands, at rest and in posture, were recorded from 15 participants with tremor diagnoses (9 Parkinson's disease, 5 essential tremor, 1 functional tremor). Video pixel movement was measured using the computing technique of optical flow, with contemporaneous accelerometer recording. Fast Fourier transform and Bland-Altman analysis were applied. Tremor amplitude was scored by 2 clinicians. RESULTS: Bland-Altman analysis of dominant tremor frequency from smartphone video compared with accelerometer showed excellent agreement: 95% limits of agreement -0.38 Hz to +0.35 Hz. In 36 of 37 videos (97%), there was <0.5 Hz difference between computer vision and accelerometer measurement. There was no significant correlation between the level of agreement and tremor amplitude. CONCLUSION: The study suggests a potential new, contactless point-and-press measure of tremor frequency within standard clinical settings, research studies, or telemedicine.

17.
J Clin Neurosci ; 81: 101-104, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33222895

RESUMO

INTRODUCTION: Eulerian magnification amplifies very small movements in video, revealing otherwise invisible motion. This raises the possibility that it could enable clinician visualisation of subclinical tremor using a standard camera. We tested whether Eulerian magnification of apparently atremulous hands reveals a Parkinsonian tremor more frequently in Parkinson's than in controls. METHOD: We applied Eulerian magnification to smartphone video of 48 hands that appeared atremulous during recording (22 hands from 11 control participants, 26 hands from 17 idiopathic Parkinson's participants). Videos were rated for Parkinsonian tremor appearance (yes/no) before and after Eulerian magnification by three movement disorder specialist neurologists. RESULTS: The proportion of hands correctly classified as Parkinsonian or not by clinicians was significantly higher after Eulerian magnification (OR = 2.67; CI = [1.39, 5.17]; p < 0.003). Parkinsonian-appearance tremors were seen after magnification in a number of control hands, but the proportion was greater in the Parkinson's hands. CONCLUSION: Eulerian magnification slightly improves clinician ability to identify apparently atremulous hands as Parkinsonian. This suggests that some of the apparent tremor revealed may be subclinical Parkinson's (pathological) tremor, and Eulerian magnification may represent a first step towards contactless visualisation of such tremor. However, the technique also reveals apparent tremor in control hands. Therefore, our method needs additional elaboration and would not be of direct clinical use in its current iteration.


Assuntos
Doença de Parkinson/diagnóstico , Tremor/diagnóstico , Feminino , Mãos , Humanos , Masculino , Pessoa de Meia-Idade , Movimento
18.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 780-783, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018102

RESUMO

Parkinson's disease is diagnosed based on expert clinical observation of movements. One important clinical feature is decrement, whereby the range of finger motion decreases over the course of the observation. This decrement has been assumed to be linear but has not been examined closely.We previously developed a method to extract a time series representation of a finger-tapping clinical test from 137 smart- phone video recordings. Here, we show how the signal can be processed to visualize archetypal progression of decrement. We use k-means with features derived from dynamic time warping to compare similarity of time series. To generate the archetypal time series corresponding to each cluster, we apply both a simple arithmetic mean, and dynamic time warping barycenter averaging to the time series belonging to each cluster.Visual inspection of the cluster-average time series showed two main trends. These corresponded well with participants with no bradykinesia and participants with severe bradykinesia. The visualizations support the concept that decrement tends to present as a linear decrease in range of motion over time.Clinical relevance- Our work visually presents the archetypal types of bradykinesia amplitude decrement, as seen in the Parkinson's finger-tapping test. We found two main patterns, one corresponding to no bradykinesia, and the other showing linear decrement over time.


Assuntos
Hipocinesia , Doença de Parkinson , Análise por Conglomerados , Humanos , Movimento , Amplitude de Movimento Articular
19.
J Neurol Sci ; 416: 117003, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32645513

RESUMO

OBJECTIVE: The worldwide prevalence of Parkinson's disease is increasing. There is urgent need for new tools to objectively measure the condition. Existing methods to record the cardinal motor feature of the condition, bradykinesia, using wearable sensors or smartphone apps have not reached large-scale, routine use. We evaluate new computer vision (artificial intelligence) technology, DeepLabCut, as a contactless method to quantify measures related to Parkinson's bradykinesia from smartphone videos of finger tapping. METHODS: Standard smartphone video recordings of 133 hands performing finger tapping (39 idiopathic Parkinson's patients and 30 controls) were tracked on a frame-by-frame basis with DeepLabCut. Objective computer measures of tapping speed, amplitude and rhythm were correlated with clinical ratings made by 22 movement disorder neurologists using the Modified Bradykinesia Rating Scale (MBRS) and Movement Disorder Society revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS). RESULTS: DeepLabCut reliably tracked and measured finger tapping in standard smartphone video. Computer measures correlated well with clinical ratings of bradykinesia (Spearman coefficients): -0.74 speed, 0.66 amplitude, -0.65 rhythm for MBRS; -0.56 speed, 0.61 amplitude, -0.50 rhythm for MDS-UPDRS; -0.69 combined for MDS-UPDRS. All p < .001. CONCLUSION: New computer vision software, DeepLabCut, can quantify three measures related to Parkinson's bradykinesia from smartphone videos of finger tapping. Objective 'contactless' measures of standard clinical examinations were not previously possible with wearable sensors (accelerometers, gyroscopes, infrared markers). DeepLabCut requires only conventional video recording of clinical examination and is entirely 'contactless'. This next generation technology holds potential for Parkinson's and other neurological disorders with altered movements.


Assuntos
Hipocinesia , Doença de Parkinson , Inteligência Artificial , Dedos , Humanos , Hipocinesia/diagnóstico , Hipocinesia/etiologia , Movimento , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico
20.
Artif Intell Med ; 110: 101966, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33250146

RESUMO

BACKGROUND: Slowness of movement, known as bradykinesia, is the core clinical sign of Parkinson's and fundamental to its diagnosis. Clinicians commonly assess bradykinesia by making a visual judgement of the patient tapping finger and thumb together repetitively. However, inter-rater agreement of expert assessments has been shown to be only moderate, at best. AIM: We propose a low-cost, contactless system using smartphone videos to automatically determine the presence of bradykinesia. METHODS: We collected 70 videos of finger-tap assessments in a clinical setting (40 Parkinson's hands, 30 control hands). Two clinical experts in Parkinson's, blinded to the diagnosis, evaluated the videos to give a grade of bradykinesia severity between 0 and 4 using the Unified Pakinson's Disease Rating Scale (UPDRS). We developed a computer vision approach that identifies regions related to hand motion and extracts clinically-relevant features. Dimensionality reduction was undertaken using principal component analysis before input to classification models (Naïve Bayes, Logistic Regression, Support Vector Machine) to predict no/slight bradykinesia (UPDRS = 0-1) or mild/moderate/severe bradykinesia (UPDRS = 2-4), and presence or absence of Parkinson's diagnosis. RESULTS: A Support Vector Machine with radial basis function kernels predicted presence of mild/moderate/severe bradykinesia with an estimated test accuracy of 0.8. A Naïve Bayes model predicted the presence of Parkinson's disease with estimated test accuracy 0.67. CONCLUSION: The method described here presents an approach for predicting bradykinesia from videos of finger-tapping tests. The method is robust to lighting conditions and camera positioning. On a set of pilot data, accuracy of bradykinesia prediction is comparable to that recorded by blinded human experts.


Assuntos
Hipocinesia , Doença de Parkinson , Teorema de Bayes , Humanos , Hipocinesia/diagnóstico , Movimento , Doença de Parkinson/diagnóstico , Smartphone
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