UVM Theses and Dissertations
Format:
Print
Author:
Christensen, Matthew
Dept./Program:
Biomedical Engineering Program
Year:
2013
Degree:
M.S.
Abstract:
There is evidence that there is a population of people who are in need of independent mobility, but are unable to achieve it through the use of a power wheelchair (PW) due to a lack of adequate control interfaces. However, it has been observed that there are individuals among this population who have useful motor output channels, which could potentially be used to control a PW if practical sensing technology for these outputs were available. In order to test whether or not these motor outputs can be harnessed to provide input to a control interface, the project presented in this thesis undertook the design, construction, and refinement of a new control interface system that can be readily adapted to an individual's particular impairment, in order to provide reliablecontrol of a PW. The resulting system of controls is referred to as SPOOCI, an acronym for Self-Referenced Personal Omni-Purpose Orthotic Control Interface. This new system revolves around the use of a pneumatic pressure sensing interface, which can be placed anywhere on the user where a reliable voluntary action (either force or motion) can be generated.
Unlike a conventional wheelchair joystick, the SPOOCI sensors can be placed in any location, ensuring that areas where the user has the best motor control are being used to drive the wheelchair. Discussed within this thesis is the sequence of engineering design steps used to successfully develop and build a working SPOOCI prototype; as well as an in-depth look at the various subsystems and components within the prototype and rationale for their selection. Also discussed is the overall system behavior, in terms of how the control signal is processed as it passes through the system, and the overall dynamics between user input and wheelchair motor output. Furthermore, this thesis presents a data logging system that was constructed and used to track the rotation history ofeach drive wheel, and the derivation of equations used to translate the data from the logging system into a plot of the driven path ofthe wheelchair. This thesis proposes that the data from the path tracking system, through a correlation of speed and accuracy, can be used to gauge the effectiveness of the SPOOCI system relative to conventional means or control.
Unlike a conventional wheelchair joystick, the SPOOCI sensors can be placed in any location, ensuring that areas where the user has the best motor control are being used to drive the wheelchair. Discussed within this thesis is the sequence of engineering design steps used to successfully develop and build a working SPOOCI prototype; as well as an in-depth look at the various subsystems and components within the prototype and rationale for their selection. Also discussed is the overall system behavior, in terms of how the control signal is processed as it passes through the system, and the overall dynamics between user input and wheelchair motor output. Furthermore, this thesis presents a data logging system that was constructed and used to track the rotation history ofeach drive wheel, and the derivation of equations used to translate the data from the logging system into a plot of the driven path ofthe wheelchair. This thesis proposes that the data from the path tracking system, through a correlation of speed and accuracy, can be used to gauge the effectiveness of the SPOOCI system relative to conventional means or control.