Automatic detection of falls and fainting

Healthcare environments have always been considered an important scenario in which to apply new technologies to improve residents and employees conditions, solve problems and facilitate the performance of tasks. In this way, the use of sensors based on user movement interaction allows solving complicated situations that should be immediately addressed, such as controlling falls and fainting spells in residential care homes. However, ensuring that all the residents are always visually controlled by at least one employee is quite complicated. In this paper, we present a ubiquitous and context-aware system focused on geriatrics and residential care homes, but it could be applied to any other healthcare centre. This system has been designed to automatically detect falls and fainting spells, alerting the most appropriate employees to address the emergency. To that end, the system is based on movement interaction through a set of Kinect devices that allows the identification of the position of a person. These devices imply some development problems that authors have had to deal with, including camera location, the detection of head movements and people in horizontal position. The proposed system allows controlling each resident posture through a notification and warning procedure. When an anomalous situation is detected, the system analyses the resident posture and, if necessary, the most adequate employee will be warned to react urgently. Ubiquity and context-awareness are essential features since the proposed system has to be able to know where any employee is and what they are doing at any time. Finally, we present the outcomes of an evaluation based on the ISO 9126-4 about the usability of the system.We would like to acknowledge the project CICYT TIN2011-27767-C02-01 from the Spanish Ministerio de Ciencia e Innovación and the Regional Goverment: Junta de Comunidades de Castilla-La Mancha PPII10-0300-4174 and PII2C09-0185-1030 projects for partially funding this work

A Machine Learning Multi-Class Approach for Fall Detection Systems Based on Wearable Sensors with a Study on Sampling Rates Selection

Falls are dangerous for the elderly, often causing serious injuries especially when the fallen person stays on the ground for a long time without assistance. This paper extends our previous work on the development of a Fall Detection System (FDS) using an inertial measurement unit worn at the waist. Data come from SisFall, a publicly available dataset containing records of Activities of Daily Living and falls. We first applied a preprocessing and a feature extraction stage before using five Machine Learning algorithms, allowing us to compare them. Ensemble learning algorithms such as Random Forest and Gradient Boosting have the best performance, with a Sensitivity and Specificity both close to 99%. Our contribution is: a multi-class classification approach for fall detection combined with a study of the effect of the sensors’ sampling rate on the performance of the FDS. Our multi-class classification approach splits the fall into three phases: pre-fall, impact, post-fall. The extension to a multi-class problem is not trivial and we present a well-performing solution. We experimented sampling rates between 1 and 200 Hz. The results show that, while high sampling rates tend to improve performance, a sampling rate of 50 Hz is generally sufficient for an accurate detection

SisFall : A Fall and Movement Dataset

ABSTRACT: Research on fall and movement detection with wearable devices has witnessed promising growth. However, there are few publicly available datasets, all recorded with smartphones, which are insufficient for testing new proposals due to their absence of objective population, lack of performed activities, and limited information. Here, we present a dataset of falls and activities of daily living (ADLs) acquired with a self-developed device composed of two types of accelerometer and one gyroscope. It consists of 19 ADLs and 15 fall types performed by 23 young adults, 15 ADL types performed by 14 healthy and independent participants over 62 years old, and data from one participant of 60 years old that performed all ADLs and falls. These activities were selected based on a survey and a literature analysis. We test the dataset with widely used feature extraction and a simple to implement threshold based classification, achieving up to 96% of accuracy in fall detection. An individual activity analysis demonstrates that most errors coincide in a few number of activities where new approaches could be focused. Finally, validation tests with elderly people significantly reduced the fall detection performance of the tested features. This validates findings of other authors and encourages developing new strategies with this new dataset as the benchmark

Elderly Fall Detection and Fall Direction Detection via Various Machine Learning Algorithms Using Wearable Sensors

The world population is aging rapidly. Some of the elderly live alone and it is observed that the elderly who live with their families frequently have to stay at home alone, especially during the working hours of adult members of the family. Falling while alone at home often results in fatal injuries and even death in elderly individuals. Fall detection systems detect falls and provide emergency healthcare services quickly. In this study, a two-step fall detection and fall direction detection system has been developed by using a public dataset and by testing 5 different machine learning algorithms comparatively. If a fall is detected in the first stage, the second stage is started and the direction of the fall is determined. In this way, the fall direction of the elderly individual can be determined for use in future researches, and a system that enables necessary measures such as opening an airbag in the direction of the fall is developed. Thus, a gradual fall detection and fall direction detection system has been developed by determining the best classifying algorithms. As a result, it has been determined that Ensemble Subspace k-NN classifier performs a little more successful classification compared to other classifiers. The classification via the test data corresponding to 30% of the total data, which was never used during the training phase, has been performed with 99.4% accuracy, and then 97.2% success has been achieved in determining the direction of falling

Recognition of Distress Calls in Distant Speech Setting: a Preliminary Experiment in a Smart Home

International audienceThis paper presents a system to recognize distress speech in the home of seniors to provide reassurance and assistance. The system is aiming at being integrated into a larger system for Ambient Assisted Living (AAL) using only one microphone with a fix position in a non-intimate room. The paper presents the details of the automatic speech recognition system which must work under distant speech condition and with expressive speech. Moreover, privacy is ensured by running the decoding on-site and not on a remote server. Furthermore the system was biased to recognize only set of sentences defined after a user study. The system has been evaluated in a smart space reproducing a typical living room where 17 participants played scenarios including falls during which they uttered distress calls. The results showed a promising error rate of 29% while emphasizing the challenges of the task

Support Vector Machine Classifiers Show High Generalizability in Automatic Fall Detection in Older Adults

Falls are a major cause of morbidity and mortality in neurological disorders. Technical means of detecting falls are of high interest as they enable rapid notification of caregivers and emergency services. Such approaches must reliably differentiate between normal daily activities and fall events. A promising technique might be based on the classification of movements based on accelerometer signals by machine-learning algorithms, but the generalizability of classifiers trained on laboratory data to real-world datasets is a common issue. Here, three machine-learning algorithms including Support Vector Machine (SVM), k-Nearest Neighbors (kNN), and Random Forest (RF) were trained to detect fall events. We used a dataset containing intentional falls (SisFall) to train the classifier and validated the approach on a different dataset which included real-world accidental fall events of elderly people (FARSEEING). The results suggested that the linear SVM was the most suitable classifier in this cross-dataset validation approach and reliably distinguished a fall event from normal everyday activity at an accuracy of 93% and similarly high sensitivity and specificity. Thus, classifiers based on linear SVM might be useful for automatic fall detection in real-world applications