Basketball for the blind

engineering undergraduates - Alissa Burkholder, Ashanna Randall and Steve Garber - have designed and built a system that uses sound emitters in the ball and on the backboard to enable blind people to play basketball.

"There are blind athletes who want an audible ball,” said Mike Bullis, business services development manager for Blind Industries and Services of Maryland, a group that aids the visually impaired and sponsored the research project. “And there are school-age children who can benefit from the hand co-ordination that comes from playing ball. Right now, blind kids can play with a ball, but only if someone is there to find it if it rolls away."

During a recent demonstration, Bullis, who is blind, was able to catch passes with the adapted ball and sink baskets on two of his three shots.

In the students’ completed system, a large piezoelectric sound emitter powered by a nine volt battery and mounted behind the backboard sends out low pulse tones to help players locate their shooting target. A remote control is used to turn it on and off. A smaller sound emitter, embedded in the basketball and powered by five three volt button batteries, sends out a higher continuous tone to tell players where the ball is.

Bullis, representing the project's sponsor, cautioned that this prototype system is not perfect. The basketball's sound pitch needs to be lowered for the comfort of players and to avoid echo problems, which would sometimes make it difficult for a blind player to identify the ball's location.

Bullis plans to consult a sports equipment maker about modifying the pitch. He also hopes to persuade a company to install the system in other sports items, including footballs and volleyballs. "The process is ongoing," he said. "but I think we'll end up with an audible ball that's going to be a huge asset to the blind community."

When the student engineers designed the system, a key hurdle was how to create a cavity in a ball to hold the electronics, while keeping it airtight. "We discovered that it's really hard to put a device inside a ball in a way that wouldn't change its characteristics," Randall said. "Weight was a consideration. If the device was too heavy, the ball wouldn't bounce or roll properly."

In their research, however, the students discovered the Spalding Infusion basketball, which is equipped with a airtight cylinder that houses a small pump.

The company provided several Infusion balls for the students to cut open and study. Spalding then provided five additional basketballs that had just the cylinder in them without the pump. That gave the students a small space in which to insert a sounding device and batteries. The opening's small size limited their options and led to a relatively high-pitched sounder.

However, the students also came up with an idea for an alternate mini-speaker system that should emit a lower pitch. They provided details on this alternative to the sponsoring organisation, for possible future developmental work.

"I don't think it's fully developed, but it's definitely a great start," Randall said.