Showing 1–12 of 44 results
A Dual-Discriminator GAN for Sleep EEG Signal Synthesis
Abstract: The interpretation of one’s overnight sleep process based on EEG signal is of importance for the inspection and treatment of various sleep-related disorders. The automatic sleep staging models have benefits as the assistant computerized tools to release the clinicians from the laborious task of manual sleep stage scoring. However, the issues of data insufficient and class imbalance are common for clinical data. The data problem is crucial to be solved when applying the automatic sleep staging models for real clinics. In this research, the network architecture of GAN (Generative Adversarial Network) is investigated by using one generator and two discriminators for the synthesis task of sleep EEG signals. The data augmentation performance by the dual-discriminator GAN and the sleep stage classification performance by combining with a typical machine learning classifier are evaluated on the sleep recording of subjects. The obtained results showed that the constructed dual-discriminator GAN is effective to generate samples which are closer to the time and frequency characteristics of real sleep EEG signal. It would be a useful method to solve the data problems for the training and optimization of automatic sleep stage classifiers in the field of sleep staging.
Keywords: Generative adversarial network; Electroencephalograph; Data augmentation; Sleep staging; Dual-discriminator
EMG-Based Recognition Method of Finger Movement Impairment Level in Post-Stroke Patients Based on Fugl-Meyer Assessment
Abstract: The restoration of finger motor functions is considered difficult during rehabilitation due to the complexity of the underlying muscles. The Fugl-Meyer Assessment (FMA) method is used by doctors to manually assess the level of finger movement impairment. However, there is a risk of evaluation errors due to inherent subjectivity. Therefore, a new, more accurate method must be developed to predict the level of impairment. This study aimed to evaluate the impairment level of finger movement based on the FMA. EMG signals were recorded from four patients while performing seven movements, and feature extraction was performed. SVM and Random Forest were used to classify the level of impairment for each movement. The SVM model obtained good results in the fourth movement, with an accuracy of 91.7% and an F1 score of 0.78.
Keywords: impairment level; finger movement; post-stroke patients; recognition.
EEG Signal Power Prediction Using DEAP Dataset
Abstract: When we listen to music, our emotions can change due to changes in our brain response. Because of this, a large number of research projects for classifying the emotional response using brain signals when listening to music through machine learning techniques emerged. On the contrary, to our knowledge, there is no previous research attempting to estimate the dynamic changes in the electroencephalogram (EEG) response under music stimuli through machine learning techniques. Therefore, in this manuscript, we proposed an approach to predict and anticipate changes in the EEG signal under music stimuli. Using the DEAP dataset, we split the EEG response to music stimuli into one-second length frames. After that, we compared the changes in the power of the brain signal of consecutive frames through two one-tailed Wilcoxon rank-sum tests. This test allowed us to label the changes in the second frame as “lower”, “similar” or “higher” signal compared to the first frame. Then, we attempted to predict these changes using a Support-Vector Machine (SVM) classifier with stratified 5-fold validation with different input combinations (only music, only brain signal, or a combination of both). Due to the use of multi-label classification with imbalanced data, we measured the results through F1-Scores. Over chance level predictions of the changes of signal power were obtained when using the previous second brain signal for the different channels and bands, especially in the frontal F3 and F4 channels.
Keywords: Electroencephalography (EEG), Music perception, Neural correlation, Machine learning, Signal classification.
Mixed-Precision Acceleration of Ultrasound Imaging Software
Evaluation of 2D and 3D Deep Learning Approaches for Automatic Segmentation of the Retinal External Limiting Membrane in Spectral Domain Optical Coherence Tomography Images
Abstract: In this work, we compared the performance of 2D and 3D versions of three state-of-the-art deep neural networks on segmenting the retinal external limiting membrane (ELM) using a publicly available image dataset of spectral-domain optical coherence tomography (OCT) scans. Based on our results, 3D networks generally outperformed the 2D networks in Dice coefficient, mean surface distance and false positive rate but lagged behind in Hausdorff distance. 3D networks also produce smoother surfaces based on mean surface curvedness.
Keywords: 2D vs. 3D Image Segmentation, Machine Learning, Annotation, External Limiting Membrane, OCT.
A sparse-NTF-based feature space construction method for automatic sleep stage identification
Abstract: Healthy sleep is essential for the normal functioning of the human body and for the maintenance of mental vitality. One’s overnight sleep is usually evaluated by several sleep stages with sleep cycles. Automatic sleep stage identification methods are effective tools for sleep staging where feature extraction is an important procedure affecting the identification performance. In this study, an automatic sleep staging method based on multi-channel EEG signals and its optimized tensor feature space is developed. Several characteristic features are calculated from the two EEG recording channels and constructed as the original tensor feature space. A non-negative tensor factorization method based on sparse improvement is developed to optimize the tensor feature space for sleep staging. A classification model is constructed based on BP neural network and the parameters are estimated by PSO algorithm. Totally 10 overnight sleep recordings were tested. The averaged classification accuracy is about 84%. The developed method can be an assistant computerized tool for sleep staging.
Keywords: Sleep staging; EEG; Non-negative tensor factorization; BP neural network; PSO
Deploying Electronic Health Records In Sports
Abstract: EHR has the advantage of providing and updating information instantaneously at any time and place, giving it a potential advantage for use in sports events and not just in hospital settings. With this in mind, we address the question: do frontline sports health providers, coaches, and athletes prefer traditional paper charts, or do they prefer a paperless version of the incident report, such as EHR? The research was conducted over three days at an organized outdoor summer sporting event, where medical providers used the EHR (Diya Sports Suite) platform to document the treatment of athletes plus spectators. Data was collected via post-event survey questionnaires from coaches, providers, and scribes to solicit their feedback on the EHR. For the medical providers, 86% of them feel that using EHR makes the treatment experience less stressful than traditional paperwork. Overall, 86% of the providers, 62% of the coaches, and 100% of the scribes prefer a paperless medical record system over the traditional paper recording system. However, this study was limited by the low number (12 documentation) of patient incidents seen by the medical team and the low number of people surveyed (19 participants). A future direction for using EHR in this sporting event would be to collect enough incidents to run analytics. Studying this data will help event organizers to identify factors that may hinder the success of the tournament and take precautions to ensure the safety of athletes, coaches, and the audience.
Keywords: Electronic health record, sporting venue
Brain-Computer Interface for Image Retrieval from EEG
Abstract: This research is motivated to gift the ability of expression to the speech deprived by building a module that extracts thoughts from the human brain and presents it to the external world as a digital image. This novel approach reconstructs the same images of different colours from the EEG brain waves. Standalone datasets are used to train the model, obtained using the Enobio8 headset. EEG signals are acquired by providing six different shapes of three unique colors as the visual stimuli. After processing these signals, EEG features are extracted using a convolutional Neural Network (CNN). The extracted features alongside noise are passed as an input to conditional Deep Convolutional Generative Adversarial Networks (cDCGANs) and conditional Generative Adversarial Networks (cGANs), which reconstruct the visual stimuli corresponding to the EEG data. The results obtained by the same are recorded and examined. The paper explicitly compares the working and performance of the cGAN and cDCGAN models.
Keywords: EEG, Image reconstruction, Deep Learning, Brain Media, Generative adversarial networks (GANs).
Predicting Oxygen Utilization & Nurse Staffing Needs For SARS-CoV-2
Abstract: Supplemental oxygen is an essential part of in-hospital care for most patients hospitalized with SARS-CoV-2 pneumonia. This study seeks to identify hospitalized patients who will require advanced oxygen support (high flow oxygen, CPAP, BiPAP, or mechanical ventilation) within 96 hours of admission using a machine learning model. This information can be useful for hospitals to plan for nurse staffing, as patients will consume more resources and will need more staff assistance.
Data from 302 SARS-CoV-2 patients was used to create a classifier to predict whether or not patients would require advanced oxygen support within 96 hours of admission. Of the 302 cases, 211 were randomly selected to train the model, and 91 were randomly selected for testing. Through a labeled dataset, we performed supervised learning by using a random forest ensemble model which included demographic, clinical comorbidities, vitals, and laboratory values. We used 5-fold cross-validation to evaluate our trained model and employed a majority vote decision across the five trained models in order to produce the final prediction for a given patient. Through the models, we yielded results through sensitivity, specificity, positive predictive value, negative predictive value, and F1 score with the 91 cases of training data. An additional 24 cases were used to test the validity of the ensemble consensus model. Approximately 40% of all patients progressed to require advanced oxygen support 96 hours after the initial presentation. Although the insight gained from the model may not definitively predict the course of an individual patient, this model may help hospital administrators plan for staffing needs with a 48-hour lead time. Patients on high oxygen support require high acuity beds, which have increased nurse-to-patient ratios. Additional samples may increase its statistical significance. Nevertheless, this model demonstrates the potential and viability of using data science to help manage hospital resources.
Keywords: COVID-19, nurse staffing, resource management, machine learning, oxygen utilization
A Research on Force Estimation from EMG with a CNN-based Deep Model
Abstract: This paper develops data-driven deep model to estimate muscle contraction force from surface electromyography (EMG) signals. The proposed estimation model is based on deep convolutional neural networks (CNNs). Information of EMG signals from both time and frequency domains has been utilized as input data to two CNN branches. Raw EMG signals are directly input into one branch in order to extract time domain characteristics, while frequency information is fed into the other CNN branch. These two branches are summarized at a concatenation layer, which is followed by three full-connected layers to estimate force levels. End point force at hand, considering the dumbbell curl exercises, has been measured using a testing apparatus, which was designed with a single point load cell. The force data is used as training data of the deep CNN EMG-force model. For validation, different structures of the CNN model are examined with an estimation index of coefficient of determination using EMG and force data of nine subjects
Keywords: EMG force estimation, CNN-based model, raw EMG signals, frequency information.
Changes in the Perception of Postoperative Delirium Before and After a Simulated Experience of Postoperative Delirium in Nursing Students
Abstract: The purpose of this study is to use Unity to recreate the hallucinations and auditory
hallucinations experienced by patients who develop delirium, and to use VR to reveal the changes in perception of delirium before and after the simulated experience of delirium to nursing college students. We used VR to recreate the ICU at night and created a video of a simulated postoperative delirium experience. The duration is 12 minutes. We set up scenes of cockroaches appearing on the ceiling, the ceiling closing in on them, people in protective clothing, and soldiers attacking at two-minute intervals. Oculus Quest was used as the head-mounted display (HMD) for viewing the VR images. The target participants were 17 students in the second to the fourth year of nursing college. The target students were asked to answer two questions before and after the viewing. The interview content was analyzed by comparing the differences in speaking time, amount of speech and content before and after the VR viewing for each student and by text mining. The results showed that using VR to simulate postoperative delirium can lead to a change in perception from understanding the inner life of patients with postoperative delirium.
Geometric Shape Statistical Analysis of Tibial Plafond with Ankle Osteoarthritis
Abstract: The etiology of ankle osteoarthritis is not enough elucidated, and similar to hip and knee
osteoarthritis, the ankle osteoarthritis caused cartilage loss and pain in daily life. However, the ankle osteoarthritis has a worse prognosis than the hip or the knee osteoarthritis. Considering the ankle osteoarthritis skeletal structure is important in selecting the appropriate surgery for the patient. Selecting the appropriate surgery will lead to an improved prognosis. X-ray images and Computed Tomography (CT) scan images are usually used to classify ankle osteoarthritis, but the evaluation of 3D bone structure is difficult and the classification based on two-dimensional measurements of X-ray and CT images may vary among medical doctors. The purpose of this study is to investigate the three-dimensional geometric deformation characteristics of tibial plafond by using statistical analysis. Deformation characteristics were found in high severity ankle osteoarthritis compared with mild group. In particular, there was a statistically significant difference in the varus deformity of the articular facet of medial malleolus and tibial plafond between stage 3B and mild group (p < 0.006), and the hyperostosis of the medial malleolus between stage 4 and mild group (p < 0.002). These results suggest that patients with severe ankle osteoarthritis have common deformity characteristics in the tibial plafond. On the contrary, there was no significant difference in the deformity of the edge of anterior and posterior tibial plafond. Such phenomena suggest that the edge of anterior and posterior tibial plafond deforms regardless of ankle osteoarthritis. This study contributes to the scientific advancement of ankle osteoarthritis surgery.