Inertial sensor based gait analysis discriminates subjects with and without visual impairment caused by simulated macular degeneration

Author(s):  
Christoph M. Kanzler ◽  
Jens Barth ◽  
Jochen Klucken ◽  
Bjoern M. Eskofier
2020 ◽  
Vol 53 (2) ◽  
pp. 15990-15997
Author(s):  
Felix Laufer ◽  
Michael Lorenz ◽  
Bertram Taetz ◽  
Gabriele Bleser

Author(s):  
Gunjan Patel ◽  
Rajani Mullerpatan ◽  
Bela Agarwal ◽  
Triveni Shetty ◽  
Rajdeep Ojha ◽  
...  

Wearable inertial sensor-based motion analysis systems are promising alternatives to standard camera-based motion capture systems for the measurement of gait parameters and joint kinematics. These wearable sensors, unlike camera-based gold standard systems, find usefulness in outdoor natural environment along with confined indoor laboratory-based environment due to miniature size and wireless data transmission. This study reports validation of our developed (i-Sens) wearable motion analysis system against standard motion capture system. Gait analysis was performed at self-selected speed on non-disabled volunteers in indoor ( n = 15) and outdoor ( n = 8) environments. Two i-Sens units were placed at the level of knee and hip along with passive markers (for indoor study only) for simultaneous 3D motion capture using a motion capture system. Mean absolute percentage error (MAPE) was computed for spatiotemporal parameters from the i-Sens system versus the motion capture system as a true reference. Mean and standard deviation of kinematic data for a gait cycle were plotted for both systems against normative data. Joint kinematics data were analyzed to compute the root mean squared error (RMSE) and Pearson’s correlation coefficient. Kinematic plots indicate a high degree of accuracy of the i-Sens system with the reference system. Excellent positive correlation was observed between the two systems in terms of hip and knee joint angles (Indoor: hip 3.98° ± 1.03°, knee 6.48° ± 1.91°, Outdoor: hip 3.94° ± 0.78°, knee 5.82° ± 0.99°) with low RMSE. Reliability characteristics (defined using standard statistical thresholds of MAPE) of stride length, cadence, walking speed in both outdoor and indoor environment were well within the “Good” category. The i-Sens system has emerged as a potentially cost-effective, valid, accurate, and reliable alternative to expensive, standard motion capture systems for gait analysis. Further clinical trials using the i-Sens system are warranted on participants across different age groups.


PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e101072 ◽  
Author(s):  
Paul Mitchell ◽  
Neil Bressler ◽  
Quan V. Doan ◽  
Chantal Dolan ◽  
Alberto Ferreira ◽  
...  

Author(s):  
Jacqueline Chua ◽  
Ching-Yu Cheng ◽  
Tien Yin Wong

General physicians have an essential role in preventing vision loss in older people. However, most vision-threatening eye disorders are initially asymptomatic and often go underdiagnosed. Therefore screening, early detection, and timely intervention are important in their management. The most common cause of visual impairment is uncorrected or undercorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, and diabetic retinopathy. Spectacles and cataract surgery can successfully restore sight for uncorrected refractive error and cataract, respectively. Visual impairment as a result of age-related macular degeneration, glaucoma, and diabetic retinopathy can be prevented with appropriate treatment if they are identified early enough. This chapter provides an overview of common age-related eye disease and visual impairment.


BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e037028
Author(s):  
Chi Chin Sun ◽  
Ting-Shuo Huang ◽  
Tsai-Sheng Fu ◽  
Chia-Yi Lee ◽  
Bing-Yu Chen ◽  
...  

ObjectivesVisual impairment is an important risk factor for fracture in the elderly population. Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment in elderly people. This study was conducted to explore the relationship between AMD and incident fractures in patients with osteoporosis (OS).DesignRetrospective analysis of Taiwan’s National Health Insurance Research Database (NHIRD).SettingA multicenter study conducted in Taiwan.Participants and controlsThe current study used the NHIRD in Taiwan between 1996 and 2011. A total of 13 584 and 54 336 patients with OS were enrolled in the AMD group and the non-AMD group, respectively.InterventionPatients with OS were included from the Taiwan’s NHIRD after exclusion, and each patient with AMD was matched for age, sex and comorbidities to four patients with non-AMD OS, who served as the control group. A Cox proportional hazard model was used for the multivariable analysis.Primary outcome measuresTransitions for OS to spine fracture, OS to hip fracture, OS to humero-radio-ulnar fracture and OS to death.ResultsThe risks of spine and hip fractures were significantly higher in the AMD group (HR=1.09, 95% CI=1.04 to 1.15, p<0.001; HR=1.18; 95% CI=1.08 to 1.30, p=0.001, respectively) than in the non-AMD group. The incidence of humero-radio-ulnar fracture between AMD and non-AMD individuals was similar (HR=0.98; 95% CI=0.90 to 1.06; p=0.599). However, the risk of death was higher in patients with OS with older age, male sex and all types of comorbidity (p<0.05), except for hyperthyroidism (p=0.200).ConclusionPatients with OS with AMD had a greater risk of spine and hip fractures than did patients without AMD.


2018 ◽  
Vol 102 (7) ◽  
pp. 855-862 ◽  
Author(s):  
Timothy R Fricke ◽  
Monica Jong ◽  
Kovin S Naidoo ◽  
Padmaja Sankaridurg ◽  
Thomas J Naduvilath ◽  
...  

PurposeWe used systematic review and meta-analysis to identify and assimilate evidence quantifying blindness and visual impairment (VI) associated with myopic macular degeneration (MMD), then derived models to predict global patterns. The models were used to estimate the global prevalence of blindness and VI associated with MMD from 2000 to 2050.MethodsThe systematic review identified 17 papers with prevalence data for MMD VI fitting our inclusion criteria. Data from six papers with age-specific data were scaled to relative age-dependent risk and meta-analysed at VI and blindness levels. We analysed variance in all MMD VI and blindness data as a proportion of high myopia against variables from the place and year of data collection, with a model based on health expenditure providing the best correlation. We used this model to estimate the prevalence and number of people with MMD VI in each country in each decade.ResultsWe included data from 17 studies comprising 137 514 participants. We estimated 10.0 million people had VI from MMD in 2015 (prevalence 0.13%, 95% CI 5.5 to 23.7 million, 0.07% to 0.34%), 3.3 million of whom were blind (0.04%, 1.8 to 7.8 million, 0.03% to 0.10%). We estimate that by 2050, without changing current interventions, VI from MMD will grow to 55.7 million people (0.57%, 29.0 to 119.7 million, 0.33% to 1.11%), 18.5 million of whom will be blind (0.19%, 9.6 to 39.7 million, 0.11% to 0.37%).ConclusionThe burden of MMD blindness and VI will rise significantly without efforts to reduce the development and progression of myopia and improve the management of MMD.


Sign in / Sign up

Export Citation Format

Share Document