Real-Time Detection of Fall From Bed Using a Single Depth Camera

Abstract

Toward the medical and living healthcare for the elderly and patients, fall from bed is a critical accident that may lead to serious injuries. To alleviate this, an essential problem is to detect this event in time for earning the rescue time. Although some efforts that resort to the wearable devices and smart healthcare room have already been paid to address this problem, the performance is still not satisfactory enough for the practical applications. In this paper, a novel fall from a bed detection method is proposed. In particular, the depth camera is used as the visual sensor due to its insensitivity to illumination variation and capacity of privacy protection. To characterize the human activity well, an effective human upper body detection approach able to extract human head and upper body center is proposed using random forest. Compared with the existing widely used human body parsing methods (e.g., Microsoft Kinect SDK or OpenNI SDK), our proposition can still work reliably when human–bed interaction happens. According to the motion information of human upper body, the fall from bed detection task is formulated as a two-class classification problem. Then, it is solved using the large margin nearest neighbor classification approach. Our method can meet the real-time running requirement with the normal computer. In experiments, we construct a fall from bed detection data set that contains the samples from 42 volunteers (26 males and 16 females) for test. The experimental results demonstrate the effectiveness and efficiency of our proposition. Note to Practitioners—This paper aims to develop the vision-based surveillance system to automatically detect fall from bed in real time under the unconstrained conditions. This cannot be well handled by using wearable devices. Our proposition can be used to construct a smart healthcare room. It is worth noting that the proposed system is insensitive to illumination variation and capable of protecting privacy due to the use of depth camera. The proposed human body extraction method is able to address the human–bed interaction well. An effective motion pattern categorization approach is applied to ensure the good separation between fall from bed and the other activities. According to the extensive experiments under the laboratory and sickroom environments, our fall from bed detection method generally can achieve acceptable result with high efficiency. Nevertheless, it is still somewhat sensitive to noise within the depth frames. In addition, when serious human–quilt interaction happens, the performance of human body extraction procedure is not satisfactory enough.