Task Prompter


Designers: Matthew Pepper and Karen Hwang
Client Coordinators: Greg Beck
Supervising Professor: Dr. Larry N. Bohs, Duke University, Department of Biomedical Engineering, Durham, NC 27708-0281


The client was a young man who attends a day program for people with autism. Approximately every 30 minutes, the participants switch to a different activity; however, our client required repeated verbal and visual prompting from the staff to make these transitions. A device was built to hold a schedule of tasks and to prompt him to perform those tasks. Activated by a radio frequency remote control, the device uses a BASIC stamp and an ISD voice-recording chip to provide an audio command to check a schedule. Several lights illuminate a visual prompt for the next activity. These cues help the client transition to his next activity with less prompting from the staff.
How 
this project helped
The task prompter was designed to help the client to transition smoothly from task to task, with less assistance from staff members, thereby increasing his independence. Gina Chapman, director of the facility that the client attends during the day, said, "The prompter device has the potential to greatly increase (the client's) independence in getting through his day! It uses his strengths of understanding picture and object cues, while compensating for his need in the area of initiation."
The overall approach to this design was to provide a visual prompt, a voice prompt, and a notebook of Boardmaker (Mayer-Johnson, Inc., Solana Beach CA) prompting cards that he was already using at his day program.

The visual prompt was created using 10 LEDs, controlled with a BASIC stamp microprocessor and driven by NPN transistors, as shown in Figure 2. The LEDs were mounted around a sign that said "Check Schedule" in the notebook (Figure 1). Upon each activation, the LEDs remained on for 10 seconds.

The voice prompt was constructed using a an ISD4002 ChipCorder(c) (Figure 3). A 9 to 3V regulator provided the supply voltage for the ISD chip from a 9V battery, which also powered the BASIC stamp. The voice prompts were generated in the following way. First, a sound file of the voice prompt was made through a computer microphone and stored as a WAV file. Next, two wires were soldered to a headphone plug, which was plugged into the headphone jack of the computer. Finally, the headphone plug wires were connected to the ISD input. As the ISD chip was recording, the WAV file was played on the computer, loading the voice prompt into the ISD. An LM386 audio amplifier connected to the ISD output provided the power necessary to drive a speaker.

The remote control circuitry was modified from a RadioShack wireless doorbell. When the remote was activated, the doorbell's output went high (5V). This signal was inverted and connected to the BASIC stamp reset pin. Because the reset pin was active low, this caused the Stamp to wake up from "sleep" mode and execute the program that turns on the visual and audio prompts. Then the Stamp went back to "sleep".

A LeapPad (LeapFrog Enterprises, Emeryville CA) was used for the notebook. The LeapPad is a learning toy that comes with spiral-bound books. The electronics of the task prompter replaced the LeapFrog's electronics, and the book was replaced with a notebook made out of laminated construction paper, spiral bound to fit into the device. Plastic sleeves, made to hold baseball cards, were cut and attached to the notebook to hold the 2"x2" Boardmaker picture cards representing the client's scheduled tasks. Velcro was also mounted to the opposite side of the picture cards so that the staff could attach objects that correspond to each task. For example, a paintbrush could be attached opposite from the picture card for the art station. The staff found that the client could transition more easily when his next task was prompted by both a picture card and a physical object.

Parts for the Task Prompter cost approximately $240.