ApneaDetector

2021 ◽  
Vol 5 (2) ◽  
pp. 1-22
Author(s):  
Xianda Chen ◽  
Yifei Xiao ◽  
Yeming Tang ◽  
Julio Fernandez-Mendoza ◽  
Guohong Cao
Keyword(s):  
Machine Learning ◽  
Sleep Apnea ◽  
Wearable Sensors ◽  
Machine Learning Techniques ◽  
Clinical Test ◽  
Learning Techniques ◽  
Apnea Detection ◽  
Hospital Visits ◽  
Calibration Techniques ◽  
Data Calibration

Sleep apnea is a sleep disorder in which breathing is briefly and repeatedly interrupted. Polysomnography (PSG) is the standard clinical test for diagnosing sleep apnea. However, it is expensive and time-consuming which requires hospital visits, specialized wearable sensors, professional installations, and long waiting lists. To address this problem, we design a smartwatch-based system called ApneaDetector, which exploits the built-in sensors in smartwatches to detect sleep apnea. Through a clinical study, we identify features of sleep apnea captured by smartwatch, which can be leveraged by machine learning techniques for sleep apnea detection. However, there are many technical challenges such as how to extract various special patterns from the noisy and multi-axis sensing data. To address these challenges, we propose signal denoising and data calibration techniques to process the noisy data while preserving the peaks and troughs which reflect the possible apnea events. We identify the characteristics of sleep apnea such as signal spikes which can be captured by smartwatch, and propose methods to extract proper features to train machine learning models for apnea detection. Through extensive experimental evaluations, we demonstrate that our system can detect apnea events with high precision (0.9674), recall (0.9625), and F1-score (0.9649).

scholarly journals Deep learning and model personalization in sensor-based human activity recognition

2022 ◽  
Author(s):  
Anna Ferrari ◽  
Daniela Micucci ◽  
Marco Mobilio ◽  
Paolo Napoletano
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Activity Recognition ◽  
Human Activity ◽  
Wearable Sensors ◽  
Human Activity Recognition ◽  
Population Diversity ◽  
Machine Learning Algorithms ◽  
Machine Learning Techniques ◽  
Learning Techniques

AbstractHuman activity recognition (HAR) is a line of research whose goal is to design and develop automatic techniques for recognizing activities of daily living (ADLs) using signals from sensors. HAR is an active research filed in response to the ever-increasing need to collect information remotely related to ADLs for diagnostic and therapeutic purposes. Traditionally, HAR used environmental or wearable sensors to acquire signals and relied on traditional machine-learning techniques to classify ADLs. In recent years, HAR is moving towards the use of both wearable devices (such as smartphones or fitness trackers, since they are daily used by people and they include reliable inertial sensors), and deep learning techniques (given the encouraging results obtained in the area of computer vision). One of the major challenges related to HAR is population diversity, which makes difficult traditional machine-learning algorithms to generalize. Recently, researchers successfully attempted to address the problem by proposing techniques based on personalization combined with traditional machine learning. To date, no effort has been directed at investigating the benefits that personalization can bring in deep learning techniques in the HAR domain. The goal of our research is to verify if personalization applied to both traditional and deep learning techniques can lead to better performance than classical approaches (i.e., without personalization). The experiments were conducted on three datasets that are extensively used in the literature and that contain metadata related to the subjects. AdaBoost is the technique chosen for traditional machine learning, while convolutional neural network is the one chosen for deep learning. These techniques have shown to offer good performance. Personalization considers both the physical characteristics of the subjects and the inertial signals generated by the subjects. Results suggest that personalization is most effective when applied to traditional machine-learning techniques rather than to deep learning ones. Moreover, results show that deep learning without personalization performs better than any other methods experimented in the paper in those cases where the number of training samples is high and samples are heterogeneous (i.e., they represent a wider spectrum of the population). This suggests that traditional deep learning can be more effective, provided you have a large and heterogeneous dataset, intrinsically modeling the population diversity in the training process.

scholarly journals Detecting Falls with Wearable Sensors Using Machine Learning Techniques

Sensors ◽  
2014 ◽  
Vol 14 (6) ◽  
pp. 10691-10708 ◽  
Author(s):  
Ahmet Özdemir ◽  
Billur Barshan
Keyword(s):  
Machine Learning ◽  
Wearable Sensors ◽  
Machine Learning Techniques ◽  
Learning Techniques

scholarly journals Calibration of Machine Learning Models

2010 ◽  
pp. 128-146 ◽  
Author(s):  
Antonio Bella ◽  
Cèsar Ferri ◽  
José Hernández-Orallo ◽  
María José Ramírez-Quintana
Keyword(s):  
Machine Learning ◽  
Single Case ◽  
Machine Learning Techniques ◽  
Average Error ◽  
Learning Models ◽  
Classifier Calibration ◽  
Learning Techniques ◽  
Probabilistic Classifier ◽  
Calibration Techniques ◽  
Machine Learning Models

The evaluation of machine learning models is a crucial step before their application because it is essential to assess how well a model will behave for every single case. In many real applications, not only is it important to know the “total” or the “average” error of the model, it is also important to know how this error is distributed and how well confidence or probability estimations are made. Many current machine learning techniques are good in overall results but have a bad distribution assessment of the error. For these cases, calibration techniques have been developed as postprocessing techniques in order to improve the probability estimation or the error distribution of an existing model. This chapter presents the most common calibration techniques and calibration measures. Both classification and regression are covered, and a taxonomy of calibration techniques is established. Special attention is given to probabilistic classifier calibration.

scholarly journals Estimating Biomechanical Time-Series with Wearable Sensors: A Systematic Review of Machine Learning Techniques

2019 ◽  
Author(s):  
Reed D. Gurchiek ◽  
Nicholas Cheney ◽  
Ryan S. McGinnis
Keyword(s):  
Machine Learning ◽  
Time Series ◽  
Wearable Sensors ◽  
Sensor Data ◽  
Machine Learning Techniques ◽  
Superior Performance ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Practical Implementation ◽  
Learning Techniques

Wearable sensors have the potential to enable comprehensive patient characterization and optimized clinical intervention. Critical to realizing this vision is accurate estimation of biomechanical time-series in daily-life, including joint, segment, and muscle kinetics and kinematics, from wearable sensor data. The use of physical models for estimation of these quantities often requires many wearable devices making practical implementation more difficult. However, regression techniques may provide a viable alternative by allowing the use of a reduced number of sensors for estimating biomechanical time-series. Herein, we review 46 articles that used regression algorithms to estimate joint, segment, and muscle kinematics and kinetics. We present a high-level comparison of the many different techniques identified and discuss the implications of our findings concerning practical implementation and further improving estimation accuracy. In particular, we found that several studies report the incorporation of domain knowledge often yielded superior performance. Further, most models were trained on small datasets in which case nonparametric regression often performed best. No models were open-sourced, and most were subject-specific and not validated on impaired populations. Future research should focus on developing open-source algorithms using complementary physics-based and machine learning techniques that are validated in clinically impaired populations. This approach may further improve estimation performance and reduce barriers to clinical adoption.

scholarly journals Apnea Detection in Polysomnographic Recordings Using Machine Learning Techniques

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2302
Author(s):  
Marek Piorecky ◽  
Martin Bartoň ◽  
Vlastimil Koudelka ◽  
Jitka Buskova ◽  
Jana Koprivova ◽  
...  
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Machine Learning Techniques ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Hyperparameter Optimization ◽  
K Nearest Neighbors ◽  
Learning Techniques ◽  
Apnea Detection ◽  
Sleep Laboratories

Sleep disorders are diagnosed in sleep laboratories by polysomnography, a multi-parameter examination that monitors biological signals during sleep. The subsequent evaluation of the obtained records is very time-consuming. The goal of this study was to create an automatic system for evaluation of the airflow and SpO2 channels of polysomnography records, through the use of machine learning techniques and a large database, for apnea and desaturation detection (which is unusual in other studies). To that end, a convolutional neural network (CNN) was designed using hyperparameter optimization. It was then trained and tested for apnea and desaturation. The proposed CNN was compared with the commonly used k-nearest neighbors (k-NN) method. The classifiers were designed based on nasal airflow and blood oxygen saturation signals. The final neural network accuracy for apnea detection reached 84%, and that for desaturation detection was 74%, while the k-NN classifier reached accuracies of 83% and 64% for apnea detection and desaturation detection, respectively.

scholarly journals Estimating Biomechanical Time-Series with Wearable Sensors: A Systematic Review of Machine Learning Techniques

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5227 ◽  
Author(s):  
Reed D. Gurchiek ◽  
Nick Cheney ◽  
Ryan S. McGinnis
Keyword(s):  
Machine Learning ◽  
Time Series ◽  
Wearable Sensors ◽  
Sensor Data ◽  
Machine Learning Techniques ◽  
Superior Performance ◽  
Estimation Accuracy ◽  
Accurate Estimation ◽  
Practical Implementation ◽  
Learning Techniques

Wearable sensors have the potential to enable comprehensive patient characterization and optimized clinical intervention. Critical to realizing this vision is accurate estimation of biomechanical time-series in daily-life, including joint, segment, and muscle kinetics and kinematics, from wearable sensor data. The use of physical models for estimation of these quantities often requires many wearable devices making practical implementation more difficult. However, regression techniques may provide a viable alternative by allowing the use of a reduced number of sensors for estimating biomechanical time-series. Herein, we review 46 articles that used regression algorithms to estimate joint, segment, and muscle kinematics and kinetics. We present a high-level comparison of the many different techniques identified and discuss the implications of our findings concerning practical implementation and further improving estimation accuracy. In particular, we found that several studies report the incorporation of domain knowledge often yielded superior performance. Further, most models were trained on small datasets in which case nonparametric regression often performed best. No models were open-sourced, and most were subject-specific and not validated on impaired populations. Future research should focus on developing open-source algorithms using complementary physics-based and machine learning techniques that are validated in clinically impaired populations. This approach may further improve estimation performance and reduce barriers to clinical adoption.

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