A speaking chair

Stephen Hawking's wheelchair was motorized, it incorporated a ventilator and a computer with a screen to help him speak and write. (Leon Neal / AFP)

Although he was paralyzed by ALS, Stephen Hawking could communicate thanks to a computer installed in his wheelchair

Physicist Stephen Hawking was diagnosed with amyotrophic lateral sclerosis (ALS) when he was only 21 years old. The doctors told him that he had two or three years to live, but Hawking surprised everyone (once again) and lived to be 76 years old.

However, the disease kept acting on his body. The motor neurons became more and more damaged and Hawking lost the ability to move. So, he spent most of his life in a wheelchair.

In the end he could not move his mouth or his lips to speak, but his mind never stopped working. Along with other scientists and researchers, Hawking found a way to continue to explain his theories.

Siempre y toda la vida #science #hawking

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Technology for Science

Stephen Hawking wheelchair, but more importantly the computer he has installed in it, allows him to perform such important actions for a scientist such as speaking, writing or surfing the Internet.

At first, during the 80s and 90s, the chair had a small computer with a button that Hawking could move using his right thumb (he could move it just a few millimeters).

The computer program showed on the screen the letters of the alphabet and a series of short instructions that Hawking could select to help him write or speak. The computer reproduced the written text with a speech synthesizer that read the words with the voice of a robot.

Hawking, who had a great sense of humor, never showed any intention to change the program to make the voice sound more natural.

In 2008, ALS didn’t allow him to move not even a finger, so they needed to develop a new system to control the computer.

The scientist could still move his right cheek slightly (as if he was winking an eye). Intel engineers, a well-known programming company, placed an infrared sensor near his cheek that detected any movement in Hawking’s face. In this way, he could continue to move the pointer across the screen.

However, writing with such rudimentary method (selecting letters one by one) was very slow. Thanks to technological advances and programming, in 2014 predictive algorithms were incorporated to accelerate the writing process, just like the dictionary in cell phones.

This communication system is known as ACAT: Assistive Context-Aware Toolkit (Context Conscious Assistance Tools). Hawking and the developers of the program decided to post this on a free platform so that all those affected by ALS or any other type of tetraplegia could use it to communicate.

“Medicine has not been able to cure me, so I rely on technology to help me communicate and live”  

Stephen Hawking

Translated by Chaplin’s Languages | Find out more in Junior Report


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