D-2: Integration of Electronic External Devices for Powered Mobility Systems
Task Leader: Barry Romich, BSE, PE (product designer/engineer)
Co-Investigators: Douglas Hobson, PhD, Katya Hill, MA, CCC-slp (clinician), Edmund LoPresti, BS (bioengineering student/electrical engineer); Donald Spaeth, MA, ABD, ATP (assistive technology practitioner/technical support), Rick Creech (consumer consultant)
Duration/Staging of Task: This is a 48-month development task that occurs in months 1-48 of the 60-month RERC cycle, commencing on January 1, 1999.
Rationale/Task Summary
The focus of this task is to design and develop an adapter to interface between various proportional wheelchair controller standards in common use, the proposed M3S standard, and the Microsoft mouse controller format. This will allow the same proportional joystick used for powered wheelchair control to also control a computer, AAC device and/or other items. Additionally, the adapter will allow a joystick of one control format to operate a powered wheelchair of another format. This development of integrated controls will increase the options available to clinicians and consumers in the powered mobility intervention process.
An early component of the task will be the determination of the practical configuration(s) of the device(s). While it is conceivable that a single device could be developed that would perform all possible information format translations, the reality may be that certain particular configurations specific to particular needs may be more practical. For example, if a common need is infrared wireless access to mouse and keyboard emulation from an M3S wheelchair control system, then having many other functions in the same unit would only serve to make it more costly to manufacture and support and more complex to apply.
Candidate formats include two-dimensional voltage and two-dimensional potentiometer (both with switch (es), Echelon (Invacare), Apple Desktop Bus (ADB), Universal Serial Bus (USB), Microsoft mouse (serial), M3S Controller Area Network (CAN), and perhaps others.
Schematic of concept
Objective and Goals
The objective is to enhance the integration and control of various assistive technologies that are used by people who rely on powered mobility systems. This objective will be realized through systematically pursuing the following goals:
Goal 1: To identify and select from existing control formats and define functional outcomes;
Goal 2: To design, fabricate, and test prototypes based on outcomes domains;
Goal 3: To transfer technology to industry and fabricate beta test units;
Goal 4: To evaluate the quality and performance of the beta test units;
Goal 5: To disseminate non-proprietary information to users, industry, and the professional community.
Progress Report (12/31/99)
Year 1 work completed includes the development and dissemination of a news release announcing the task. The purpose of this was to gather email contact information on individuals expressing an interest in the task. This list of persons will be contacted with a request to complete a survey, the purpose of which is to guide the definition of the first design effort. A similar request will be posted on at least two list serves, ACOLUG and RESNA. The survey has been completed. It is a web based survey that provides for automated processing of survey responses. The task summary and survey were submitted to the University of Pittsburgh Institutional Review Board.
Approval was received in January of Year 2. Next steps include dissemination of the survey, summary of responses, definition of the device configuration(s), and design, fabrication, and testing of prototype(s).
Progress Report (12/31/00)
Year 2 highlights on the Joystick to Mouse Adapter (JMA) started with the Institutional Review Board approval of the survey, available at <http://www.prentrom.com:8080/pitt.edu/RERC-II/D-2/survey/survey.html>. The survey was promoted and the results were collected and compiled. The 2000 RESNA Conference provided an opportunity to briefly present the project and to meet with others interested in this work. An update and request for additional input was sent to wheelchair and control manufacturers. Invacare responded with announcement of the recent release of new software that provides joystick position information and then followed up with the loan of a Mk. IV controller with this feature. Decision was made to use the Invacare Mk. IV for initial testing. Review of the literature was accomplished to compare anticipated performance using velocity vs. position control. A paper on this issue was submitted for presentation at RESNA 2001. It was determined that testing of both would be done, comparing to traditional mouse control. The definition of the JMA was developed. Hardware for the prototype JMA device was identified and acquired and software development was started. Next steps include submission of the IRB proposal for subject testing, alpha testing of the JMA prototype, fabrication of beta test units, and subject testing.
Progress Report (12/31/01)
Year 3 progress focused on the development and preliminary testing of the Joystick to Mouse Adapter. The software to covert the Invacare Mk. IV controller joystick position reporting into computer mouse emulation was completed. Three modes were implemented: velocity control (directed scanning), position control (pointing), and a hybrid (combination of scanning and pointing). 2001 RESNA Conference presentations reported on the survey results and on the JMA system development work. Internal alpha testing of the JMA and the traditional switch-based joystick to mouse emulation using the ASL hardware was done using six able-bodied subjects. Two tasks were used in the testing: a target acquisition task and a screen keyboard typing task. Preliminary data from that testing showed the average performance using the pointing and hybrid modes of the JMA exceeded that of the traditional switch-based scanning approach by 65% and 40% respectively for the two tasks. The performance using proportional scanning was not as good, but still better than the switch-based approach. This preliminary test is reported in a paper submitted for presentation at the 2002 RESNA Conference. The IRB application for subject testing was developed and submitted. Next steps, following IRB approval, include fabrication of one or two additional test systems, recruitment and testing of subjects, analysis and dissemination of results, and commercialization.
Expected Outcomes
Successful outcomes from this task will result in the ability to efficiently integrate individual components of assistive technology in a way that performance compromises will be minimized or eliminated. The powered wheelchair, on-board accessories, and other electronic devices (desktop computer, ECU, etc.) all will be able to be chosen on the basis of their own merits, not based on limits of their compatibility with each other. This outcome will significantly expand the options for consumers, and if adopted as an industry standard, should largely eliminate incompatibility problems in the future.
Publications/Reports
Hill, K, LoPresti, EF, Romich, B, Spaeth, D. Joystick to mouse adaptor. RESNA Annual Conference 2001, Reno, NV paper submitted
LoPresti, EF, Romich, BA, Speath, DM, Hill, KJ, Hobson, D. Toward development of an interface device for proportional mouse emulation through a power wheelchair controller. RESNA Annual Conference 2001, Reno, NV paper submitted
Contact Person: Barry Romich
Acknowledgement:
The primary support for the WMRC is provided by
The Department of Rehabilitation Science and Technology (RST) of the School of Health and Rehabilitation Sciences
