When arthritis so crippled Auguste Renoir's hands that he could not hold a brush to paint, the impressionist artist tied it to his forearms to continue working.

A group of University of Arizona electrical-engineering students have applied that spirit and some modern technology to devise a system to assist artists challenged by physical disabilities.

Led by UA senior Angela Foss, the student engineers designed the system for the nonprofit group Arts for All Inc. The organization sponsors artistic programs for people with and without disabilities.

The Artist's Interface System is designed for people with limited mobility because of nervous-system disorders such as muscular dystrophy and cerebral palsy. The device consists of a computer assisted laser pointer attached to the artist's head.

A computer screen projected on the artist's workspace is used as a virtual palette that lets them communicate thickness of line, texture, color and shape to a volunteer "tracker" working with the artist.

Mo Olson, 25, a psychology student at Pima Community College and Arts for All artist, said the new system is a big improvement over the old device, which she found annoying.

"Sometimes the headgear would interfere with the headrest. I can go without the headrest but some others can't," she said.

The new system also eliminates the guesswork previously required between the artist and tracker.

"There's no question to what people want because it's all right there. There's absolutely no guesswork and if there is, it is much easier.

"It's simpler and complicated at the same time because there are more choices. Especially for the nonverbal kids, they have more options," she said.

In the spring of 2005, Arts for All approached the current senior electrical engineering class for help in improving an existing Laser Art Technique device.

"We were able to pick which projects we wanted to work on and I think that our entire team chose the Arts for All project," said Foss.

Other projects dealt with basic circuit design while the Arts for All project provided both a creative and human element absent in the other projects, said Foss.

The new system replaces an existing device consisting of foam headgear with a laser pointer attachment. The laser point allowed the artist to select a brush and indicate where they wanted a line to start and end but allowed for little else in terms of communication.

Using the laser point as a guide, the tracker would use a ruler and painstakingly work with the artist, who would indicate where to start and stop by pointing to a certain area.

Harriet Morton, art teacher and trained tracker at Arts for All Inc., describes the old laser process as slow and frustrating for the artist.

For a nonverbal cerebral-palsy student like Jake Gilbert, who uses a sometimes faulty communication device, trying to convey to Morton the amount and type of texture he wanted was time-consuming and difficult.

The new system, designed by the UA electrical engineering students, streamlines the process dramatically.

Originally, the students wanted to use a panel of phototransistors to track laser movement from the headgear. This also would have involved using a microprocessor to compute the data which in turn would require more hardware and more software, according to Foss.

Operating on a shoestring budget of $2,000, the cost of thousands of phototransistors costing $30 each would have been too costly, said the group's technical leader, Indra Wiryadinanta.

Instead, the group turned to a less expensive and simple design.

Their revised idea involved a projected computer screen that has a variety of choices from colors, brush-head types, and options for different texture techniques. Also, a grid system is projected on the canvas allowing students to indicate precisely where they want their figures to start.

With the new system, an activity that would have taken more than 45 minutes now takes two minutes.

Though the process is faster, the relationship between tracker and artist remains important.

It's a game of 20 questions for a tracker and though devices like the LAT help in clarifying certain things the student wants to do, you have to continually ask questions to get at visions, said Morton.

"All I am is their hands," said Morton. "I'm performing the physical part that they can't do, but the work is all theirs."

Besides Gilbert, six other students use this device, which is available only in Tucson.