Instrumented shoes for daily activity monitoring in healthy and at risk populations

Daily activity reflects the health status of an individual. Ageing and disease drastically affect all dimensions of mobility, from the number of active bouts to their duration and intensity. Performing less activity leads to muscle deterioration and further weakness that could lead to increased fall risk. Gait performance is also affected by ageing and could be detrimental for daily mobility. Therefore, activity monitoring in older adults and at risk persons is crucial to obtain relevant quantitative information about daily life performance. Activity evaluation has mainly been established through questionnaires or daily logs. These methods are simple but not sufficiently accurate and are prone to errors. With the advent of microelectromechanical systems (MEMS), the availability of wearable sensors has shifted activity analysis towards ambulatory monitoring. In particular, inertial measurement units consisting of accelerometers and gyroscopes have shown to be extremely relevant for characterizing human movement. However, monitoring daily activity requires comfortable and easy to use systems that are strategically placed on the body or integrated in clothing to avoid movement hindrance. Several research based systems have employed multiple sensors placed at different locations, capable of recognizing activity types with high accuracy, but not comfortable for daily use. Single sensor systems have also been used but revealed inaccuracies in activity recognition. To this end, we propose an instrumented shoe system consisting of an inertial measurement unit and a pressure sensing insole with all the sensors placed at the shoe/foot level. By measuring the foot movement and loading, the recognition of locomotion and load bearing activities would be appropriate for activity classification. Furthermore, inertial measurement units placed on the foot can perform detailed gait analysis, providing the possibility of characterizing locomotion. The system and dedicated activity classification algorithms were first designed, tested and validated during the first part of the thesis. Their application to clinical rehabilitation of at risk persons was demonstrated over the second part. In the first part of the thesis, the designed instrumented shoes system was tested in standardized conditions with healthy elderly subjects performing a sequence of structured activities. An algorithm based on movement biomechanics was built to identify each activity, namely sitting, standing, level walking, stairs, ramps, and elevators. The rich array of sensors present in the system included a 3D accelerometer, 3D gyroscope, 8 force sensors, and a barometer allowing the algorithm to reach a high accuracy in classifying different activity types. The tuning parameters of the algorithm were shown to be robust to small changes, demonstrating the suitability of the algorithm to activity classification in older adults. Next, the system was tested in daily life conditions on the same elderly participants. Using a wearable reference system, the concurrent validity of the instrumented shoes in classifying daily activity was shown. Additionally, daily gait metrics were obtained and compared to the literature. Further insight into the relationship between some gait parameters as well as a global activity metric, the activity âcomplexityâ, was discussed. Participants positively rated their comfort while using the system... (Please refer to thesis for full abstract

Physical activity recognition via minimal in-shoes force sensor configuration

We propose a new minimal wearable system and a classifier for physical activity recognition. The configuration is solely based on two force sensors placed anteriorly and posteriorly under the feet. To find the optimal sensor configuration, we estimated the total force under the feet during daily activities. The estimation was based on a linear regression model built upon the forces estimated over selected areas from the dense mesh of high-resolution sensors of a commercially-available force sensing system. The best estimate of the total force, which also indicated the best sensor configuration, was fed to the activity recognition algorithm to provide the final output. The analysis indicated that the optimal locations which allowed estimating the total force with a minimal RMS error (40N) were the central part of rear foot and forefoot. Using this configuration and the activity classification algorithm, the classification accuracy for the basic activities such as sitting, standing and walking were 93.8%, 99.5% and 93.4%, respectively. These values demonstrate the high accuracy of the proposed system and are very encouraging for recognition of additional types of activities of daily-living in the next stage

Instrumented shoes for activity classification in the elderly

Quantifying daily physical activity in older adults can provide relevant monitoring and diagnostic information about risk of fall and frailty. In this study, we introduce instrumented shoes capable of recording movement and foot loading data unobtrusively throughout the day. Recorded data were used to devise an activity classification algorithm. Ten elderly persons wore the instrumented shoe system consisting of insoles inside the shoes and inertial measurement units on the shoes, and performed a series of activities of daily life as part of a semi-structured protocol. We hypothesized that foot loading, orientation, and elevation can be used to classify postural transitions, locomotion, and walking type. Additional sensors worn at the right thigh and the trunk were used as reference, along with an event marker. An activity classification algorithm was built based on a decision tree that incorporates rules inspired from movement biomechanics. The algorithm revealed excellent performance with respect to the reference system with an overall accuracy of 97% across all activities. The algorithm was also capable of recognizing all postural transitions and locomotion periods with elevation changes. Furthermore, the algorithm proved to be robust against small changes of tuning parameters. This instrumented shoe system is suitable for daily activity monitoring in elderly persons and can additionally provide gait parameters, which, combined with activity parameters, can supply useful clinical information regarding the mobility of elderly persons. (C) 2015 Elsevier B.V. All rights reserved

(Re)framing resistance and (re)forging solidarity : negotiating the politics of space, race, and gender in Maria Magdalena Campos-Pons’ Habla La Madre

This study provides one of the first examinations of Habla La Madre, a 2014 performance by Afro-Cuban artist Maria Magdalena Campos-Pons launched in the Guggenheim Museum. The performance stems from practices that resulted in the marginalization and exclusion of artists of color from hegemonic cultural institutions such as the Guggenheim. Habla La Madre concerns itself with the politics of identity in its desire to function as a tool for (re)building African Diasporic solidarity. The project looks at historical, cultural, religious, and mythological texts in order to investigate Habla La Madre as a manifestation of Campos-Pons’ hybridized “exilic,” “female,” “African,” and “Cuban” identities. (Re)Framing Resistance and (Re)Forging Solidarity: Negotiating the Politics of Space, Race, and Gender in Maria Magdalena Campos-Pons’ Habla La Madre situates the performance in a history of public performative acts of resistance enacted by enslaved Africans, Afro-Cubans, and African American communities which is a primary goal of this study. The project pays close attention to Habla La Madre as it intersects with the politics of space. A critical objective of this study is to understand the sociopolitical implications of Campos-Pons’ acts of spatial transformation and spatial appropriation around and within the museum. The project also looks at Campos-Pons’ introduction of Santería into the Guggenheim as an attempt at its institutionalization. A history of African and African Diasporic altar production structures an investigation into Campos-Pons’ construction of an altar within the Guggenheim. As a performance that challenges discriminatory practices of art institutions, Habla La Madre situates itself within the genre of institutional critique. The project highlights its consistencies, deviations, and contributions to the field. This research also draws upon conversations with the artist to determine the extent to which her peers have influenced the production and goals of Habla La Madre. Most prior research on Campos-Pons focuses on her practice as mourning; however, this project focuses on the cultural diffusion and celebration the performance brings about.Art Histor