Julia O’Rourke, Peter Doblar, Jakub Felkl, Mukund Kumar, Patrick Pace (University of Texas at Austin)
Abstract
An automatic, switch activated paper-counting device was designed to enable people with disabilities to more easily perform jobs related to paper handling, such as distributing fliers or stuffing envelopes. This paper-counting device allows individuals with limited mobility, dexterity, or cognitive ability to specify the number of pages desired in a batch and produce a stack of pages which can then be distributed or stuffed into envelopes. The device is switch activated, ergonomic, and contains both visual and audio feedback for the user so that it may be used in the workplace by people with a wide range of disabilities.
Background
Rosedale School, part of the Austin Independent School District, serves a wide range of students from 3 to 22 years old with severe and multiple physical and cognitive disabilities. The mission of Rosedale is to help its students become more independent by providing them with the skills necessary to “live, work, and enjoy life in their community” (1). In order to gain important skills for the workplace, many students at Rosedale participate in a vocational training program. Many of the jobs these students perform, such as stuffing envelopes and distributing fliers, involve counting and stacking sheets of paper. However, due to physical or cognitive disabilities, some students are unable to count out the required number of pages and stack them. Instead, they must rely on a teacher to count pages for them, which can be a time-consuming process of little benefit to the student.
Problem Statement
The goal of this project was to create a device that would allow the students at Rosedale to independently count and stack pages as part of their vocational training. The device needed to be safe, durable, switch-activated, and multisensory in order to allow students with a wide range of abilities to be as independent as possible while using the device to accomplish the given task.
Methods
The product design methodology presented in Otto and Wood (2) was followed when designing the paper-counting device. Interviews were conducted with teachers, physical therapists, and administrators at Rosedale, and students were observed in order to aid the group in assessing their needs. An extensive list of customer needs for the paper counter was developed from the interviews and observations. A House of Quality was created and used to translate the most critical customer needs into engineering requirements. Then, a Black Box Model, Activity Diagram, and Functional Model were generated. A group brainstorming session with mind-mapping was run, a morphological matrix was created, and 6-3-5 was used to generate concepts. The most feasible concept variant was selected, and from this concept an alpha prototype was constructed and presented to Angela DelGrande, a teacher at Rosedale and the team contact for the project. Based on the experiences assembling the Alpha prototype and the feedback, the prototype was redesigned and reconstructed into the final version of the paper counter.
Alpha Prototype
Mechanism and Electronics
The housing and paper-handling mechanism from a Dell brand Lexmark printer was selected to be utilized in the final design. It was chosen for 4 reasons: 1) the counting mechanism’s reliability and accuracy, 2) the large input paper tray which can hold up to 500 sheets of paper, 3) the ease of disassembly, and 4) the professional appearance and layout of the device. The professional appearance is important because it resembles office products the students may encounter in the future such as industrial printers, fax machines, and copiers. The original electronics were removed and space was cut in the interior housing in order to make room for our electronics and controls.
A new motor attachment was designed so that the paper-handling mechanism could be run by a motor relocated in the lower housing. This motor attachment was adapted and press fit onto the original drive shaft. The new shaft/motor assembly was relocated inside the housing and was mounted with a specially designed bracket to minimize vibration and noise.
Sensors were mounted in and on the housing to add functionality and safety features to the paper counter. An optical/tactile counting sensor (an optical sensor which registers the movement of a tactile arm) was mounted on the housing to detect and count paper as it passes from the lower input tray to the upper output tray. A tactile ‘Empty Tray’ sensor was mounted in the input tray to stop the motors automatically if the tray runs out of paper. Additionally, a tactile ‘Open Tray’ sensor was installed on the door of input tray which automatically shuts off the motors if the tray is opened. This sensor is a safety feature which prevents the user from accessing the inside of the printer when the mechanism is in operation.
A 6 Volt power source is used to run the sensors, motors, and display. Two Parallax STAMP microcontrollers manage all of the electrical system. A fuse was included as an additional safety feature.
Interface
The primary challenge for the team was to make a device that would accommodate individuals with a wide range of disabilities who needed to learn a variety of vocational skills. To better accommodate individuals with visual impairments, a 1”, 3-digit, 7-segment readout was chosen to display the stipulated number of pages as well as the counting process. A keypad was used for numerical input to aid students who are learning counting skills and who would benefit from becoming accustomed to the layout of a standard numeric keypad. A big button keypad was selected to further aid students with visual impairments and those who lack fine motor skills.
Colored red and green indicator lights are used to communicate the status of the paper-counting process. A red light indicates counting is in progress. A blinking red light indicates an error (paper jam, the paper tray is open, or out of paper). A solid green light indicates that the counting procedure has ceased and it is now safe to remove the counted pages. These red and green lights reinforce the students’ knowledge of symbolic indicators commonly used in electronics found in offices.
Three options for the actuation of the counting process are provided to accommodate students with differing levels of dexterity. For the students who are working on developing their fine motor skills and who would benefit from becoming familiarized with a standard keypad, the * button can be used to initiate the counting process. For students with more limited motor skills, a mounted mini mac switch is available on the control pad interface which allows them to interact with the machine. A big mac adapter is included on the paper counter’s control panel so that students with even more limited motor skills can use personalized switches, such as a head switch mounted to a wheelchair.
Final Beta Design
The process of interacting with the machine helps to develop the students’ understanding of causal relations. By hitting the pound key or mac switch, the students initiate a causal process in which a light turns on, the machine begins to hum, the mechanism in the paper tray can be seen moving, and paper stacks at the end of the output tray.
The paper counter was designed to either be operated by one student working independently, or by a team composed of as many as three students who each perform different tasks related to paper-counting. In order to achieve this functional versatility and allow the paper counter to be used to teach students both independence and teamwork, the architecture of the paper counter and the layout of the user interfaces had to be designed carefully. It was critical to make the keypad, at least one of the start options, and the output tray all accessible in one location for students working independently. However, it was of equal importance to distribute these interfaces spatially around the counter to allow as many as three students to work comfortably at the same time.
Results
A durable, switch activated paper-counting device which would allow students with severe and multiple disabilities to independently count and stack pages was developed. The device includes a number of safety features: moving parts were made inaccessible though the placement of the output tray and switches were incorporated which prevent the motor from running when the input paper tray is opened. Electrical safety devices, such as the fuse, were also incorporated. The device was designed to be accessible to as many students as possible and included colored indicator lights, a large-print keypad, audio feedback, and big mac switch adapter. The final paper-counter is safe, durable, switch-activated, and multisensory in order to allow students with a wide range of abilities to be as independent as possible while using the device to accomplish the given task.
Discussion
The final beta design was unveiled at Rosedale and was met with enthusiasm. The design generated a lot of excitement from students, who were eager to learn how to use the counter and successfully operate it themselves in front of their teachers and peers. The teachers at Rosedale were impressed by the design’s professional appearance, its reliability, and its multisensory and adaptable interface that makes it engaging and accessible to a wide variety of students. Four months after the presentation of the paper counter at Rosedale, it was apparent, from speaking with the teachers, that the device fulfilled the needs of the students. Currently, the paper counter is being used twice a month by the students in vocational training programs at the school.
Cost/Implications
The entire project including the proof of concept, alpha prototype, and final beta prototype cost $325.52; this value does not include the cost of the Lexmark printers, DC motor, and Big Red Twist switch which were donated to the group. The group estimated the cost of reproducing the design in a number of scenarios. If the paper-counter were reproduced on a small-scale for use by another school, it would cost approximately $870 due to additional materials and labor costs. However, if the paper-counter were mass-produced using injection molding, it would cost approximately $275.
During the customer needs interviews, the teachers and administrators at Rosedale indicated that the maximum cost that would be considered by the school for an educational paper-counting device was $1000. The group’s estimates for the cost of reproducing the paper-counter on both a large and small scale indicate that doing so would be likely to be economically-feasible for offices and other schools.
Acknowledgments
This design was developed as part of ME 392M: Product Design, Development, and Prototyping, a graduate mechanical engineering course at the University of Texas at Austin. The group would like to thank our professors Dr. Wood and Dr. Crawford for their guidance on this project.
References
[1] Sanford, John. (n.d.) Rosedale School. Retrieved from<http://www.austinisd.org/schools/ website.phtml?id=117>.
[2] Otto, K.,& Wood, K. (2001). Product Design: Techniques in Reverse Engineering, Systematic Design, and New Product Development. New York: Prentice-Hall.