Designers: Jeff Heyman, Dave Alspector
Client Coordinators: Greg Beck, Jennifer Bell, Gina Chapman
Supervising Professor: Dr. Larry N. Bohs
Our client was a man with autism who relied on supervisors to enforce task durations and schedule. We designed a device to limit this supervision. The Task Cueing Timer (TCT) uses visual, auditory, and tactile stimuli to cue him to star and stop a task. A progression of colored, blinking lights helps him to anticipate the end of his activities. Start, Finish, and Reward windows provide additional visual cueing. An audible buzzer and vibrating wristband also help to signal the end of a task. It is hoped that the TCT will help the client better understand his task beginnings, their completions, and his next activity, and thereby give him more independence in his daily routine.
How this project helped
In addition to his autism, the client also is affected by CHARGE syndrome, and has deafness and visual impairments, seeing primarily with his left eye. This combination of disabilities makes the goal of improving his independence a challenge. The TCT was designed with careful input from the client’s three therapists, as well as his mother, to provide signals and stimuli that would most attract and interest him. After five months of use, the client’s supervisor, Jennifer Bell, commented, “It has been going well. I would consider us very much still in the teaching phase of its use. (The client) loves the lights and will attend to it for a certain period of time, but not always the time set. He sometimes puts his head down while it is on, and misses some of the lights moving along towards “finished”. For that matter, the vibration device has come in handy. He will look up when the device starts to vibrate, whereupon we show him the “break is finished” or whatever the next card happens to be and he then begins to process the transition. So as of yet he does not understand that when the timer goes off, he should transition, but with the continued pairing, I think the association could be made. The teaching process is a long one, but advantages have been noticed! Thank you so much for all the work you have done.”
The TCT consists of two main parts. The first part is the user interface, mounted on the top of the enclosure, which allows the supervisor to set the time duration and cueing mechanisms of the TCT. The second part includes the visual stimuli of the front display and the additional audible and tactile cues.
The user interface comprises an LCD display, 3 cue toggle switches, 4 momentary pushbuttons for setting the time duration, and a power switch. The 4-digit LCD display can be set in increments of 1 or 5 minutes using two of the pushbuttons; the other two buttons are for “start/stop” and “reset”. The cue switches toggle to select any combination of visual, audible, or tactile stimuli. Timer accuracy was tested and confirmed to be accurate to within one second for periods up to 60 minutes.
The front of the TCT is shown in Figure 1. The visual stimuli include a string of large LEDs that slowly approach the “reward window”, changing from green to red as time progresses. At the start, the first green LED on the left blinks for a period of time, then stays on. Then the next green LED blinks and stays on, and so on. At task completion, an illuminated slide in the reward window (upper right) cues the client to his next activity. The client is familiar with these slides, and thus the design allows easy incorporation into his routines. Illuminated start and finish windows reinforce the beginning and ending of the time durations. If the audible cue is selected, a buzzer sounds to signal the completion of a task. If the tactile cue is selected, a vibrating wristband activates upon task completion.
Figure 2 shows the electrical schematic for the hardware involved in cueing. The PIC 16F84 processor controls all cues through its output ports. The signals are either fed through 555 timer circuitry, or through an inverter, to drive blinking or continuous activation, respectively. Complete connections are shown for the first 555 timer, enclosed with a dashed box. All pins found on the left side of PIC16F84 are shared by a second PIC processor, which controls a Maxim LCD driver, and a Varitronix 4-digit LCD display, as shown in Figure 3.
An adjustable stand allows the TCT to be positioned at an appropriate viewing angle, either on a table top or over the back of a chair, and a carrying strap provides portability. Rechargeable NiMH batteries provide long battery life and low maintenance. Battery life testing confirmed at least 8 hours of use before recharging. The batteries are charged via an external charger, which plugs into the TCT when it is not being used.
The cost of parts for the project was approximately $220.