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.

GAL@Home: a feasibility study of sensor-based in-home fall detection.

BACKGROUND: A considerable proportion of falls occur within the domestic environment. Sensor-based identification of falls in seniors' homes could help them to remain autonomous and self-sufficient in their own homes. The objective of this study was to evaluate fall detection systems within the home environment using optical and accelerometric sensor systems. METHODS: Portable triaxial accelerometers and optical sensors were used to detect falls in subjects with known problems of mobility and a recent fall history. RESULTS: Three subjects were investigated with the system. Overall nine falls occurred during the study period. Four falls were recorded by the accelerometric system and one fall by the optical system. Subjects with increased risk of falling as measured with mobility and fall risk assessments tend to fall more frequently. CONCLUSION: The study shows that there is a considerably large difference between fall-detector evaluation studies in domestic environments and in laboratory trials.

Electromyographic analysis of trunk-muscle activity during stable, unstable and unilateral bridging exercises in healthy individuals.

BACKGROUND: Spinal pain can result in unilateral atrophy of spinal muscles. Understanding side-to-side muscle activity during exercises can help clinicians address these deficits. This study determined if variations of bridging exercises specifically activated side-to-side trunk-muscle activity. METHOD: Using surface electromyography on 20 healthy subjects (16 females), age 25.45 (± 3.57) years, height 166 (± 0.8) cm, weight 63.35 (± 12.70) kg, muscle activity of left and right lumbar multifidus, iliocostalis lumborum thoracis (ICLT), rectus abdominis (RA) and external oblique (EO) was recorded during eight bridging exercises with stable, unstable and unilateral (left-leg off the ground) conditions. RESULTS: There were significant side-to-side differences in abdominal-muscle activity during all unstable exercises (mean difference range from 3.10 %MVC for RA to 9.86 %MVC for EO), and during all unilateral exercises (mean difference range from 3.22 %MVC for RA to 9.41 %MVC for EO), with the exception of RA in exercise-7. For the back muscles, there were significant side-to-side differences for multifidus during all unilateral exercises (mean difference range 5.35 %MVC to 11.72 %MVC), with the exception of exercise-5. None of the bilateral exercises (stable or unstable) produced side-to-side differences for multifidus. For ICLT only exercise-3 produced significant side-to-side differences with a mean difference of 5.5 %MVC. In all cases where significant differences were noted, the left side of the muscles demonstrated the higher values. CONCLUSION: The results suggest that specific exercises (unilateral/unstable) can target specific sides of trunk muscles.