Client Coordinators: Angela Escalante
Designers: Caitlin Fearing, Jordan Yoder, Aidan Burke
Supervising Professor: Kevin Caves and Richard Goldberg
INTRODUCTION
Our client is an adult male with quadriplegia. He spends most of his time in bed or in a manual wheel chair. Unless a nurse is present to assist him, he is not able to switch between activities he enjoys such as reading, watching TV, and using his computer. He does, however, have control of his head and neck and is skilled with both a mouth stick and sip-and-puff switch. We developed a custom worktable that can be placed in front of the client, and it enables him to switch between activities utilizing his mouthstick skills. We designed the table so that it is quick and easy to set up, as well as portable and height adjustable to allow for use when in bed or in his chair. It uses a lazy Susan to allow the client to independently switch between different activities. It is compact so that the client can reach everything with his mouthstick, and the lazy Susan rotation is motorized because the client lacks the ability to turn the table manually.
SUMMARY OF IMPACT
This custom work table will provide the client with increased independence, so that he can choose between reading a book, controlling the television remote, and using his computer at any time. The client commented, “it’s really nice that I will always be able to reach my mouth stick and my sip-and-puff straw.”
TECHNICAL DESCRIPTION
The final design used a donated hospital table as the base for the device. The table rolls on wheels and it is height adjustable so that it can be adjusted to fit the client’s bed or chair. Because the table is designed to roll up to a bed from the side, it is a cantilever design with support only on one end. To prevent the table from bowing under the weight of the lazy-Susan, book, and computer, we reinforced the table with a solid wooden beam underneath.
For the lazy Susan, we mounted a 24’’ diameter circle of ¾” oak onto lazy-Susan bearings, which were then mounted on top of the table. In addition, we cut a 1.5’’ diameter hole through the center of the oak and the table to allow wires from the computer to pass through. This prevented tangling of the wires during rotation. The oak circle was stained to match the color of the hospital table.
The book stand consists of two wooden triangles that support the back of a commercial book holder and two wooden cubes that prevent the base from slipping forward without interfering with page turning. The holder can be easily removed by simply leaning it forward and lifting up.
To control the television, we purchase a commercial large-buttoned remote control, which he can access with his mouth stick. The remote control was Velcroed onto a raised stand on the table, in a location that is easy for our client to access.
The client accesses the different activities with a sip-and-puff straw and a mouthstick. We constructed a circular wooden tube to hold the sip-and-puff straw. The tube has an adjustable screw that holds the straw in place. This was mounted onto the rotating lazy Suzan. We designed a mouth stick holder using a piece of PVC cut in half and capped at one end. The capped end was screwed to a flexible gooseneck device, which was then reinforced with a second gooseneck for additional support. The goosenecks allow the mouth stick holder to always be available to the client. A button mount was fashioned around the lower half of the holder to allow the client easy access to the control buttons. These are mounted to the stationary part of the table so that they are always within reach.
To rotate the table, we used a commercial motorized rotary tool, attached to a 4’’ diameter hard foam circle that pushes against the outer edge of the 24” lazy Susan. As the foam circle slowly rotates, it rotates the lazy Susan. The motor is attached to the back of the table along with the control circuit. The circuit consists of a voltage regulator and two relays. Power comes from a 12V DC wall transformer, which is fed to the regulator that drops the voltage to 1.86V. This is fed to the relay coils, which control the voltage polarity that goes to the rotary tool, allowing rotation in either direction. The circuit is controlled by two large, normally-open pushbuttons. When the user presses a button, it closes the corresponding relay, starting rotation of the table. Each button rotates the table in a different direction. The circuit also contains two normally-closed buttons that function as limit switches. They are positioned under the lazy Susan and when depressed by a wooden knob underneath the rotating oak circle, they become open circuits and stop rotation in one direction. This prevents the table from rotating more than 360 degrees in either direction, which would cause the wires to tangle.
Total cost of the device is $240.