Title :
Wheelchair seating evaluation system ∼ Introduction of system functions ∼
Author :
Hanafusa, A. ; Ouki, K. ; Miyazaki, Koji ; Komeda, Takashi ; Ikeda, Takashi ; Suzuki, Nobuhiro ; Hattori, Asobu
Author_Institution :
Dept. of Biosci. & Eng., Shibaura Inst. of Technol., Saitama, Japan
Abstract :
In this study, a system for evaluating the wheelchair seating posture is introduced. The system consists of three subsystems: a seating posture changing system, a seating posture analysis system, and a propulsion analysis system. The seating posture changing system uses pneumatically controlled airbags installed in the wheelchair seat to change the posture of the patient and aims to generate a good posture heuristically. The seating posture analysis system uses seat sensors, video cameras, and whose analysis software to measure and analyze the current posture by seat sensors. One of the features of the analysis system is that the shape of the spine is estimated virtually, as the shape is one of the best indicators of a patient´s posture. From the current seating posture, the propulsion analysis system estimates the posture, driving force, and muscular forces necessary to propel the wheelchair. Basic hardware and software for the pneumatically controlled functions have been developed for the posture changing system, and the displacements of the human body were measured by a 3D motion analysis system when four airbags were filled with air independently. A method to estimate the spinal shape by the finite element method (FEM) using beam elements has been developed for the seating posture analysis system. This method has a fast processing time and takes external forces into consideration. A method that can estimate the position of the neutral axis of the spine from markers placed on body surfaces was also developed. For the propulsion analysis system, propulsion motion and muscular forces of a subject in the wheelchair with a seat cushion or a back seat cushion were analyzed. Future work includes the development of the remaining functions, such as the overlay display function of the video camera images and sensor data, and the integration of the entire system.
Keywords :
bone; finite element analysis; handicapped aids; image motion analysis; inflatable structures; motion control; pneumatic systems; position control; position measurement; propulsion; seats; stereo image processing; wheelchairs; 3D motion analysis system; FEM; analysis software; back seat cushion; beam element; driving force; finite element method; human body displacement measurement; muscular force; overlay display function; patient posture change; pneumatically controlled airbag; pneumatically controlled function; position estimation; posture measurement; propulsion analysis system; propulsion motion; seat sensor; seating posture analysis system; seating posture changing system; sensor data; spine neutral axis; system function; video camera image; virtual spine shape estimation; wheelchair seating evaluation system; wheelchair seating posture; Finite element methods; Force; Force measurement; Propulsion; Shape; Solid modeling; Wheelchairs;
Conference_Titel :
Mechatronics (MECATRONICS) , 2012 9th France-Japan & 7th Europe-Asia Congress on and Research and Education in Mechatronics (REM), 2012 13th Int'l Workshop on
Conference_Location :
Paris
Print_ISBN :
978-1-4673-4770-9
Electronic_ISBN :
978-1-4673-4771-6
DOI :
10.1109/MECATRONICS.2012.6451025