Multimodal sensor-based fall detection within the domestic environment of elderly people.

BACKGROUND: Falls represent a major threat to the health of the elderly and are a growing burden on the healthcare systems. With the growth of the elderly population within most societies efficient fall detection becomes increasingly important; however, existing fall detection systems still fail to produce reliable results. OBJECTIVES: A study was carried out on sensor-based fall detection, analysis of falls with the help of fall protocols and the analysis of user acceptance of fall detection sensor technology through questionnaires. MATERIAL AND METHODS: A total of 28 senior citizens were recruited from a German community-dwelling population. The primary goal was a sensor-based detection of falls with accelerometers, video cameras and microphones. Details of the falls were analyzed with the help of medical geriatric assessments and standardized fall protocols. The study duration was 8 weeks and required a maximum of nine visits per subject. RESULTS: The study participants were 28 subjects with a mean age of 74.3 and a standard deviation (SD) of ± 6.3 years of which 12 were male and 16 female. A total of 1225.7 measurement days were recorded from all participants and the algorithms detected 2.66 falls per day. During the study period 15 falls occurred and 12 of these falls were correctly recognized by the fall detection system. CONCLUSION: Current fall detection technologies work well under laboratory conditions but it is still problematic to produce reliable results when these technologies are applied to real life conditions. Acceptance towards the sensors decreased after study participation although the system was generally perceived as useful or very useful.

Defining the user requirements for wearable and optical fall prediction and fall detection devices for home use.

One of the major problems in the development of information and communication technologies for older adults is user acceptance. Here we describe the results of focus group discussions that were conducted with older adults and their relatives to guide the development of assistive devices for fall detection and fall prevention. The aim was to determine the ergonomic and functional requirements of such devices and to include these requirements in a user-centered development process. A semi-structured interview format based on an interview guide was used to conduct three focus group discussions with 22 participants. The average age was 75 years in the first group, 68 years in the second group and 50 years in the third group (relatives). Overall, participants considered a fall prediction system to be as important as a fall detection system. Although the ambient, unobtrusive character of the optical sensor system was appreciated, wearable inertial sensors were preferred because of their wide range of use, which provides higher levels of security. Security and mobility were two major reasons for people at risk of falling to buy a wearable and/or optical fall prediction and fall detection device. Design specifications should include a wearable, non-stigmatising sensor at the user's wrist, with an emergency option in case of falling.

A surgical telemanipulator for femur shaft fracture reduction.

BACKGROUND: We present a surgical telemanipulator system supporting long bone fracture reduction procedures. This paper gives an overview of the robotic system developed by our working group and describes a possible workflow for telemanipulated fracture reduction. The concepts enabling an intuitive control of the robot using a joystick with force feedback as input device are also described. METHODS: With our robotic set-up we performed a test series, in order to evaluate the achievable reposition accuracies and operation times. 11 femoral shaft fractures in seven human donors have been reduced with the telemanipulator and the results have been compared with those achieved by conventional manual and navigated manual repositions. RESULTS: All fractures in our test series could be reduced successfully with the telemanipulator, achieving a mean rotational deviation of 4.9 degrees in axial direction and 2.5 degrees and 3.5 degrees in AP and lateral direction. We could find no statistically significant difference between the accuracies achieved by the telemanipulator and those achieved by the two manual procedures. The image intensifier usage times of our telemanipulated repositions were conspicuously lower compared to the conventional manual repositions and statistically significant lower compared to the navigated repositions. CONCLUSION: We could show that robot-assisted fracture reduction is possible, yielding good accuracies and a conspicuous reduction of X-ray irradiation. However, we also show the limitations regarding reposition accuracies of telemanipulated fracture reduction when it is based on 2D X-ray imaging only. From the combination of 3D imaging, automated computation of the reduction parameters, and automated force/torque guided reduction by the robot we expect to overcome these limitations in our future work.