Deep Learning for Vision-Based Fall Detection System: Enhanced Optical Dynamic Flow

Accurate fall detection for the assistance of older people is crucial to reduce incidents of deaths or injuries due to falls. Meanwhile, a vision-based fall detection system has shown some significant results to detect falls. Still, numerous challenges need to be resolved. The impact of deep learning has changed the landscape of the vision-based system, such as action recognition. The deep learning technique has not been successfully implemented in vision-based fall detection systems due to the requirement of a large amount of computation power and the requirement of a large amount of sample training data. This research aims to propose a vision-based fall detection system that improves the accuracy of fall detection in some complex environments such as the change of light condition in the room. Also, this research aims to increase the performance of the pre-processing of video images. The proposed system consists of the Enhanced Dynamic Optical Flow technique that encodes the temporal data of optical flow videos by the method of rank pooling, which thereby improves the processing time of fall detection and improves the classification accuracy in dynamic lighting conditions. The experimental results showed that the classification accuracy of the fall detection improved by around 3% and the processing time by 40 to 50ms. The proposed system concentrates on decreasing the processing time of fall detection and improving classification accuracy. Meanwhile, it provides a mechanism for summarizing a video into a single image by using a dynamic optical flow technique, which helps to increase the performance of image pre-processing steps.Comment: 16 page

Hardware for recognition of human activities: a review of smart home and AAL related technologies

Activity recognition (AR) from an applied perspective of ambient assisted living (AAL) and smart homes (SH) has become a subject of great interest. Promising a better quality of life, AR applied in contexts such as health, security, and energy consumption can lead to solutions capable of reaching even the people most in need. This study was strongly motivated because levels of development, deployment, and technology of AR solutions transferred to society and industry are based on software development, but also depend on the hardware devices used. The current paper identifies contributions to hardware uses for activity recognition through a scientific literature review in the Web of Science (WoS) database. This work found four dominant groups of technologies used for AR in SH and AAL—smartphones, wearables, video, and electronic components—and two emerging technologies: Wi-Fi and assistive robots. Many of these technologies overlap across many research works. Through bibliometric networks analysis, the present review identified some gaps and new potential combinations of technologies for advances in this emerging worldwide field and their uses. The review also relates the use of these six technologies in health conditions, health care, emotion recognition, occupancy, mobility, posture recognition, localization, fall detection, and generic activity recognition applications. The above can serve as a road map that allows readers to execute approachable projects and deploy applications in different socioeconomic contexts, and the possibility to establish networks with the community involved in this topic. This analysis shows that the research field in activity recognition accepts that specific goals cannot be achieved using one single hardware technology, but can be using joint solutions, this paper shows how such technology works in this regard

Deep Learning in Demand Side Management: A Comprehensive Framework for Smart Homes

The advent of deep learning has elevated machine intelligence to an unprecedented high level. Fundamental concepts, algorithms, and implementations of differentiable programming, including gradient-based measures such as gradient descent and backpropagation, have powered many deep learning algorithms to accomplish millions of tasks in computer vision, signal processing, natural language comprehension, and recommender systems. Demand-side management (DSM) serves as a crucial tactic on the customer side of meters which regulates electricity consumption without hampering the occupant comfort of homeowners. As more residents participate in the energy management program, DSM will further contribute to grid stability protection, economical operation, and carbon emission reduction. However, DSM cannot be implemented effectively without the penetration of smart home technologies that integrate intelligent algorithms into hardware. Resident behaviors being analyzed and comprehended by deep learning algorithms based on sensor-collected human activities data is one typical example of such technology integration. This thesis applies deep learning to DSM and provides a comprehensive framework for smart home management. Firstly, a detailed literature review is conducted on DSM, smart homes, and deep learning. Secondly, the four papers published during the candidate’s Ph.D. career are utilized in lieu of thesis chapters: “A Demand-Side Load Event Detection Algorithm Based on Wide-Deep Neural Networks and Randomized Sparse Backpropagation,” “A Novel High-Performance Deep Learning Framework for Load Recognition: Deep-Shallow Model Based on Fast Backpropagation,” “An Object Surveillance Algorithm Based on Batch-Normalized CNN and Data Augmentation in Smart Home,” “Integrated optimization algorithm: A metaheuristic approach for complicated optimization.” Thirdly, a discussion section is offered to synthesize ideas and key results of the four papers published. Conclusion and directions for future research are provided in the final section of this thesis

Automated human fall recognition from visual data

Falls are one of the greatest risks for the older adults living alone at home. This research presents a novel visual-based fall detection approach to support independent living for older adults in an indoor environment. The aim of the research was to investigate appropriate methods for detecting falls through analysing the motion and shape of the human body. Several techniques for automatically detecting falls have been proposed. The existing technologies can be classified into three main groups of fall detectors, namely: ambient device-based, wearable sensor-based and computer vision-based techniques. Ambient device-based techniques use vibration or pressure sensors to capture the sound and vibration for detecting the presence and position of a person. Although these devices are inexpensive and do not disturb the user, the detection rate is rather low and many false alarms are generated. Wearable devices use different sensors such as accelerometer and gyroscopes to capture the human body movement information and detect falls. However, older adults often forget to wear them. Wearable sensors are also known to be too invasive as they require wearing and carrying various uncomfortable devices. Much work has been undertaken to investigate the use of visual-based sensors for fall detection using single, multiple, and omnidirectional cameras. The proposed research reported in this thesis uses a single camera to detect a moving object using a background subtraction algorithm. The next step is to extract robust features which describe the change in human shape and to discriminate falls from other activities like lying and sitting. These features are based on motion, change in the human shape feature, projection histogram features and temporal change of head position. Features extracted from the human silhouette are finally fed into various machine learning classifiers for fall detection evaluation. The ability to distinguish a fall action depends mainly on the quality of the classifier inputs, therefore, the features of the extracted human silhouette play a key role in the effectiveness and robustness of detecting human falls. In this research, the timed Motion History Image (tMHI) method is applied for motion segmentation. In addition, the motion information was combined with other features extracted from the fitted ellipse around the human body to discriminate actual fall from other activities. Fall detection methods can be divided into two main categories; thresh- old based methods and machine learning-based methods. This research presents threshold-based methods to distinguish between Activities of Daily Living (ADL) and falls. Fall events can be detected if the measured features values higher than pre-determined threshold values. Results show that falls can be distinguished from ADL with an accuracy of 99:82%, using our recording dataset. In addition, various machine learning methods were compared to evaluate their abilities to accurately detecting falls. Experimental results show efficiency and reliability of the proposed fall detection approach with high fall detection rate of 99:60% and low false alarm 2:62% tested with UR Fall Detection dataset. Additionally, A set of experiments have been conducted using our recording dataset, the results indicate that the proposed approach achieves high fall detection rate 99:94% and low false alarm 0:02%

Human Activity Recognition and Fall Detection Using Unobtrusive Technologies

As the population ages, health issues like injurious falls demand more attention. Wearable devices can be used to detect falls. However, despite their commercial success, most wearable devices are obtrusive, and patients generally do not like or may forget to wear them. In this thesis, a monitoring system consisting of two 24×32 thermal array sensors and a millimetre-wave (mmWave) radar sensor was developed to unobtrusively detect locations and recognise human activities such as sitting, standing, walking, lying, and falling. Data were collected by observing healthy young volunteers simulate ten different scenarios. The optimal installation position of the sensors was initially unknown. Therefore, the sensors were mounted on a side wall, a corner, and on the ceiling of the experimental room to allow performance comparison between these sensor placements. Every thermal frame was converted into an image and a set of features was manually extracted or convolutional neural networks (CNNs) were used to automatically extract features. Applying a CNN model on the infrared stereo dataset to recognise five activities (falling plus lying on the floor, lying in bed, sitting on chair, sitting in bed, standing plus walking), overall average accuracy and F1-score were 97.6%, and 0.935, respectively. The scores for detecting falling plus lying on the floor from the remaining activities were 97.9%, and 0.945, respectively. When using radar technology, the generated point clouds were converted into an occupancy grid and a CNN model was used to automatically extract features, or a set of features was manually extracted. Applying several classifiers on the manually extracted features to detect falling plus lying on the floor from the remaining activities, Random Forest (RF) classifier achieved the best results in overhead position (an accuracy of 92.2%, a recall of 0.881, a precision of 0.805, and an F1-score of 0.841). Additionally, the CNN model achieved the best results (an accuracy of 92.3%, a recall of 0.891, a precision of 0.801, and an F1-score of 0.844), in overhead position and slightly outperformed the RF method. Data fusion was performed at a feature level, combining both infrared and radar technologies, however the benefit was not significant. The proposed system was cost, processing time, and space efficient. The system with further development can be utilised as a real-time fall detection system in aged care facilities or at homes of older people