9,022 research outputs found
Explaining Deep Learning Models for Age-related Gait Classification based on time series acceleration
Gait analysis holds significant importance in monitoring daily health,
particularly among older adults. Advancements in sensor technology enable the
capture of movement in real-life environments and generate big data. Machine
learning, notably deep learning (DL), shows promise to use these big data in
gait analysis. However, the inherent black-box nature of these models poses
challenges for their clinical application. This study aims to enhance
transparency in DL-based gait classification for aged-related gait patterns
using Explainable Artificial Intelligence, such as SHAP.
A total of 244 subjects, comprising 129 adults and 115 older adults (age>65),
were included. They performed a 3-minute walking task while accelerometers were
affixed to the lumbar segment L3. DL models, convolutional neural network (CNN)
and gated recurrent unit (GRU), were trained using 1-stride and 8-stride
accelerations, respectively, to classify adult and older adult groups. SHAP was
employed to explain the models' predictions.
CNN achieved a satisfactory performance with an accuracy of 81.4% and an AUC
of 0.89, and GRU demonstrated promising results with an accuracy of 84.5% and
an AUC of 0.94. SHAP analysis revealed that both CNN and GRU assigned higher
SHAP values to the data from vertical and walking directions, particularly
emphasizing data around heel contact, spanning from the terminal swing to
loading response phases. Furthermore, SHAP values indicated that GRU did not
treat every stride equally.
CNN accurately distinguished between adults and older adults based on the
characteristics of a single stride's data. GRU achieved accurate classification
by considering the relationships and subtle differences between strides. In
both models, data around heel contact emerged as most critical, suggesting
differences in acceleration and deceleration patterns during walking between
different age groups
Possible complete miscibility of alloys
The stabilities of alloys and related superlattices are
investigated by ab initio pseudopotential calculations. We find that the
superlattices in (111) orientations have the lowest formation
energy among many short-range ordered structures due to the smallest
number of B-C and C-N bonds. Based on the calculated formation energies at
several compositions and for various ordered structures and assuming
thermodynamic equilibrium, the solid solution phase diagram of
alloys is constructed. We find that the complete
miscibility of alloys is possible, which is in contrast
with previous theoretical predictions but in agreement with experimental
reports.Comment: 6 pages, 3 figure
Establishing Central Sensitization Inventory Cut-off Values in patients with Chronic Low Back Pain by Unsupervised Machine Learning
Human Assumed Central Sensitization is involved in the development and
maintenance of chronic low back pain (CLBP). The Central Sensitization
Inventory (CSI) was developed to evaluate the presence of HACS, with a cut-off
value of 40/100 based on patients with chronic pain. However, various factors
including pain conditions (e.g., CLBP), and gender may influence this cut-off
value. For chronic pain condition such as CLBP, unsupervised clustering
approaches can take these factors into consideration and automatically learn
the HACS-related patterns. Therefore, this study aimed to determine the cut-off
values for a Dutch-speaking population with CLBP, considering the total group
and stratified by gender based on unsupervised machine learning. In this study,
questionnaire data covering pain, physical, and psychological aspects were
collected from patients with CLBP and aged-matched pain-free adults (referred
to as healthy controls, HC). Four clustering approaches were applied to
identify HACS-related clusters based on the questionnaire data and gender. The
clustering performance was assessed using internal and external indicators.
Subsequently, receiver operating characteristic analysis was conducted on the
best clustering results to determine the optimal cut-off values. The study
included 151 subjects, consisting of 63 HCs and 88 patients with CLBP.
Hierarchical clustering yielded the best results, identifying three clusters:
healthy group, CLBP with low HACS level, and CLBP with high HACS level groups.
Based on the low HACS levels group (including HC and CLBP with low HACS level)
and high HACS level group, the cut-off value for the overall groups were 35, 34
for females, and 35 for. The findings suggest that the optimal cut-off values
for CLBP is 35. The gender-related cut-off values should be interpreted with
caution due to the unbalanced gender distribution in the sample.Comment: 31 pages, 5 tables, 3 figure
Airway neutrophilian in bronchiectasis: the role of TNF-α in vivo
Session - Respiratory & Critical Care Medicine: no. S-RC-5published_or_final_versio
Effects of ferroelectric-poling-induced strain on the quantum correction to low-temperature resistivity of manganite thin films
Author name used in this publication: H. L. W. ChanAuthor name used in this publication: H. S. Luo2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Automated Detection of Leakage in Fluorescein Angiography Images with Application to Malarial Retinopathy
The detection and assessment of leakage in retinal fluorescein angiogram images is important for the management of a wide range of retinal diseases. We have developed a framework that can automatically detect three types of leakage (large focal, punctate focal, and vessel segment leakage) and validated it on images from patients with malarial retinopathy. This framework comprises three steps: vessel segmentation, saliency feature generation and leakage detection. We tested the effectiveness of this framework by applying it to images from 20 patients with large focal leak, 10 patients with punctate focal leak, and 5,846 vessel segments from 10 patients with vessel leakage. The sensitivity in detecting large focal, punctate focal and vessel segment leakage are 95%, 82% and 81%, respectively, when compared to manual annotation by expert human observers. Our framework has the potential to become a powerful new tool for studying malarial retinopathy, and other conditions involving retinal leakage
A New Procedure for Treating a Sebaceous Cyst: Removal of the Cyst Content with a Laser Punch and the Cyst Wall with a Minimal Postponed Excision
Three main techniques are used to excise sebaceous cysts: conventional wide excision, minimal excision, and punch biopsy excision. A new method with two steps is proposed. First, a laser is used to make a small hole for removal of the content. Then the cyst wall is removed entirely with a minimal excision about 1 month later. With this method, the cyst is completely removed with only a small scar. It offers a good alternative for eradication of uninfected cysts, especially large cysts or cysts located in areas of thick skin or cosmetic concern
Visualization of Data for Ambient Assisted Living Services
Ambient assisted living (AAL) services that provide support for people to remain in their homes are increasingly being used in healthcare systems around the world. Typically, these ambient assisted living services provide additional information though location-awareness, presence-awareness, and context-awareness capabilities, arising from the prolific use of telecommunications devices including sensors and actuators in the home of the person receiving care. In addition there is a need to provide abstract information, in context, to local and remote stakeholders. There are many different viewing options utilizing converged networks and the resulting explosion in data and information has resulted in a new problem, as these new ambient assisted living services struggle to convey meaningful information to different groups of end users. The article discusses visualization of data from the perspective of the needs of the differing end user groups, and discusses how algorithms are required to contextualize and convey information across location and time. In order to illustrate the issues, current work on nighttime AAL services for people with dementia is described
Up-regulation of circulating adhesion molecules in stable bronchiectasis
Session - Respiratory & Critical Care Medicine: no. S-RC-4published_or_final_versio
Unified force law for granular impact cratering
Experiments on the low-speed impact of solid objects into granular media have
been used both to mimic geophysical events and to probe the unusual nature of
the granular state of matter. Observations have been interpreted in terms of
conflicting stopping forces: product of powers of projectile depth and speed;
linear in speed; constant, proportional to the initial impact speed; and
proportional to depth. This is reminiscent of high-speed ballistics impact in
the 19th and 20th centuries, when a plethora of empirical rules were proposed.
To make progress, we developed a means to measure projectile dynamics with 100
nm and 20 us precision. For a 1-inch diameter steel sphere dropped from a wide
range of heights into non-cohesive glass beads, we reproduce prior observations
either as reasonable approximations or as limiting behaviours. Furthermore, we
demonstrate that the interaction between projectile and medium can be
decomposed into the sum of velocity-dependent inertial drag plus
depth-dependent friction. Thus we achieve a unified description of low-speed
impact phenomena and show that the complex response of granular materials to
impact, while fundamentally different from that of liquids and solids, can be
simply understood
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