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About this Article
Written by: Michele Kawate
Written on: June 4th, 2011
Tags: transportation, biomedical engineering, computer science
Thumbnail by: Petter Kallioinen/Wikimedia Commons
About the Author
Michele was a senior majoring in biomedical engineering at USC in 2011. She is originally from Honolulu, Hawaii and enjoys hiking, exploring LA, and eating great food.
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Volume XIII Issue II > Thought-Controlled Wheelchair
Brain-computer interfaces have offered the opportunity for highly disabled patients with motor disabilities to live more normal lives. The recent innovations in thought-controlled wheelchairs using EEG technology will allow patients to not only communicate with their surroundings but to also navigate around them. The development of this technology could potentially make a huge impact on the health care industry and the lives of those confined to the boundary of their own bodies.

Introduction

One of our biggest fears is being trapped in small, enclosed spaces. Now imagine being trapped inside of your own body. Completely conscious, you hear everything that people say around you and you can see perfectly fine. You have completely functional cognitive ability; the only problem is that you cannot move or speak. You strain to lift your legs so that you can find somebody, but they won’t budge. You want to scream for help but your mouth does not open because your facial muscles are impaired. You are a prisoner of your own body and there is no way to communicate with the outside world. Is there a way to escape?
The medical term for being trapped in your own body is Locked-in Syndrome. This is where the patient has full awareness but is not able to communicate or move due to the paralysis of voluntary muscles [1]. This fully paralyzing condition may not be common, but partial paralysis is a very real problem. Today, there are about 6 million Americans that are paralyzed to some extent. To put that into perspective, 1 out of 50 Americans are at least partially paralyzed [2].
Paralysis has many causes. It occurs because of injury to the nervous system. The leading causes of paralysis are stroke (29%), damage to the spinal cord (23%), and multiple sclerosis (17%) [3]. Other causes may be degenerative neurological diseases or brain injury. There is no real cure to patients with major body paralysis.
However, the advancements in neurotechnology in the area of brain-computer interfaces may finally allow patients suffering from some form of paralysis to live more independent lives. The development of this technology may be the light at the end of a long tunnel for those trapped in the prisons of their bodies.

The Brain-Computer Interface

A brain-computer interface (BCI) allows the brain to communicate with an external device. It converts the user’s thoughts into actions executed by a computer (Fig. 1).
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Figure 1: A man communicating with a computer through BCI.
The mechanism of the BCI can be broken down into the following steps. First, the user visualizes performing a specific simple task, such as moving their right hand. The brain emits specific signals associated with the intent which in this case involves moving the right hand [4]. This electrical activity is measured in voltage differences using an Electroencephalogram​, or EEG technology, and is filtered and amplified [5]. Then, a computer interprets the signal and learns the brain patterns associated with moving the right hand. Lastly, the computer software is programmed to recognize this specific pattern so that a certain action will execute every time the user visualizes moving their right hand.