 |
|
Clinical trial shows quadriplegics can operate powered wheelchair with tongue drive system
July 07, 2009An assistive technology that enables individuals to maneuver a powered wheelchair or control a mouse cursor using simple tongue movements can be operated by individuals with high-level spinal cord injuries, according to the results of a recently completed clinical trial.
"This clinical trial has validated that the Tongue Drive system is intuitive and quite simple for individuals with high-level spinal cord injuries to use," said Maysam Ghovanloo, an assistant professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology. "Trial participants were able to easily remember and correctly issue tongue commands to play computer games and drive a powered wheelchair around an obstacle course with very little prior training."
At the annual conference of the Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) on June 26, the researchers reported the results of the first five clinical trial subjects to use the Tongue Drive system. The trial was conducted at the Shepherd Center, an Atlanta-based catastrophic care hospital, and funded by the National Science Foundation and the Christopher and Dana Reeve Foundation.
The clinical trial tested the ability of these individuals with tetraplegia, as a result of high-level spinal cord injuries (cervical vertebrae C3-C5), to perform tasks related to computer access and wheelchair navigation -- using only their tongue movements.
At the beginning of each trial, Ghovanloo and graduate students Xueliang Huo and Chih-wen Cheng attached a small magnet -- the size of a grain of rice -- to the participant's tongue with tissue adhesive. Movement of this magnetic tracer was detected by an array of magnetic field sensors mounted on wireless headphones worn by the subject. The sensor output signals were wirelessly transmitted to a portable computer, which was carried on the wheelchair.
The signals were processed to determine the relative motion of the magnet with respect to the array of sensors in real-time. This information was then used to control the movements of the cursor on a computer screen or to substitute for the joystick function in a powered wheelchair. Details on use of the Tongue Drive for wheeled mobility were published in the June 2009 issue of the journal IEEE Transactions on Biomedical Engineering.
Ghovanloo chose the tongue to operate the system because unlike hands and feet, which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases.
Before using the Tongue Drive system, the subjects trained the computer to understand how they would like to move their tongues to indicate different commands. A unique set of specific tongue movements was tailored for each individual based on the user's abilities, oral anatomy and personal preferences. For the first computer test, the user issued commands to move the computer mouse left and right. Using these commands, each subject played a computer game that required moving a paddle horizontally to prevent a ball from hitting the bottom of the screen.
After adding two more commands to their repertoire -- up and down -- the subjects were asked to move the mouse cursor through an on-screen maze as quickly and accurately as possible.
Then the researchers added two more commands -- single and double mouse clicks -- to provide the subject with complete mouse functionality. When a randomly selected symbol representing one of the six commands appeared on the computer screen, the subject was instructed to issue that command within a specified time period. Each subject completed 40 trials for each time period.
After the computer sessions, the subjects were ready for the wheelchair driving exercise. Using forward, backward, right, left and stop/neutral tongue commands, the subjects maneuvered a powered wheelchair through an obstacle course.
The obstacle course contained 10 turns and was longer than a professional basketball court. Throughout the course, the users had to perform navigation tasks such as making a U-turn, backing up and fine-tuning the direction of the wheelchair in a limited space. Subjects were asked to navigate through the course as fast as they could, while avoiding collisions.
Each subject operated the powered wheelchair using two different control strategies: discrete mode, which was designed for novice users, and continuous mode for more experienced users. In discrete mode, if the user issued the command to move forward and then wanted to turn right, the user would have to stop the wheelchair before issuing the command to turn right. The stop command was selected automatically when the tongue returned to its resting position, bringing the wheelchair to a standstill.
"Discrete mode is a safety feature particularly for novice users, but it reduces the agility of the wheelchair movement," explained Ghovanloo. "In continuous mode, however, the user is allowed to steer the powered wheelchair to the left or right as it is moving forward and backward, thus making it possible to follow a curve."
Each subject completed the course at least twice using each strategy while the researchers recorded the navigation time and number of collisions. Using discrete control, the average speed for the five subjects was 5.2 meters per minute and the average number of collisions was 1.8. Using continuous control, the average speed was 7.7 meters per minute and the average number of collisions was 2.5.
While this initial performance trial only required six tongue commands, the Tongue Drive system can potentially capture a large number of tongue movements, each of which can represent a different user command. The ability to train the system with as many commands as an individual can comfortably remember and having all of the commands available to the user at the same time are significant advantages over the common sip-n-puff device that acts as a simple switch controlled by sucking or blowing through a straw.
Some sip-n-puff users also consider the straw to be a symbol of their disability. Since Tongue Drive users simply wear headphones that are commonly worn to listen to music, the system is more acceptable to potential users.
John Anschutz, manager of the assistive technology program at the Shepherd Center, identified advantages the Tongue Drive system has over the tongue-touch keypad.
"The Tongue Drive system seems to be much more supportable if there were a failure of some component within the system. With the old tongue-touch keypad, if the system went down then the user lost all of the functions of the wheelchair, phone, computer and environmental control," explained Anschutz. "Ghovanloo's approach should be much more repairable should a fault arise, which is critical for systems for which so much function is depended upon."
A future system upgrade will be to move the sensors inside the user's mouth, according to Ghovanloo. This will be an important step for users who are very impaired and cannot reposition the system for best results, according to Anschutz.
"All of the subjects successfully completed the computer and powered wheelchair navigation tasks with their tongues without difficulty, which demonstrates that the Tongue Drive system can potentially provide individuals unable to move their arms and hands with effective control over a wide variety of devices they use in their daily lives," said Ghovanloo.
Georgia Institute of Technology Research News
The clinical trial tested the ability of these individuals with tetraplegia, as a result of high-level spinal cord injuries (cervical vertebrae C3-C5), to perform tasks related to computer access and wheelchair navigation -- using only their tongue movements.
At the beginning of each trial, Ghovanloo and graduate students Xueliang Huo and Chih-wen Cheng attached a small magnet -- the size of a grain of rice -- to the participant's tongue with tissue adhesive. Movement of this magnetic tracer was detected by an array of magnetic field sensors mounted on wireless headphones worn by the subject. The sensor output signals were wirelessly transmitted to a portable computer, which was carried on the wheelchair.
The signals were processed to determine the relative motion of the magnet with respect to the array of sensors in real-time. This information was then used to control the movements of the cursor on a computer screen or to substitute for the joystick function in a powered wheelchair. Details on use of the Tongue Drive for wheeled mobility were published in the June 2009 issue of the journal IEEE Transactions on Biomedical Engineering.
Ghovanloo chose the tongue to operate the system because unlike hands and feet, which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases.
Before using the Tongue Drive system, the subjects trained the computer to understand how they would like to move their tongues to indicate different commands. A unique set of specific tongue movements was tailored for each individual based on the user's abilities, oral anatomy and personal preferences. For the first computer test, the user issued commands to move the computer mouse left and right. Using these commands, each subject played a computer game that required moving a paddle horizontally to prevent a ball from hitting the bottom of the screen.
After adding two more commands to their repertoire -- up and down -- the subjects were asked to move the mouse cursor through an on-screen maze as quickly and accurately as possible.
Then the researchers added two more commands -- single and double mouse clicks -- to provide the subject with complete mouse functionality. When a randomly selected symbol representing one of the six commands appeared on the computer screen, the subject was instructed to issue that command within a specified time period. Each subject completed 40 trials for each time period.
After the computer sessions, the subjects were ready for the wheelchair driving exercise. Using forward, backward, right, left and stop/neutral tongue commands, the subjects maneuvered a powered wheelchair through an obstacle course.
The obstacle course contained 10 turns and was longer than a professional basketball court. Throughout the course, the users had to perform navigation tasks such as making a U-turn, backing up and fine-tuning the direction of the wheelchair in a limited space. Subjects were asked to navigate through the course as fast as they could, while avoiding collisions.
Each subject operated the powered wheelchair using two different control strategies: discrete mode, which was designed for novice users, and continuous mode for more experienced users. In discrete mode, if the user issued the command to move forward and then wanted to turn right, the user would have to stop the wheelchair before issuing the command to turn right. The stop command was selected automatically when the tongue returned to its resting position, bringing the wheelchair to a standstill.
"Discrete mode is a safety feature particularly for novice users, but it reduces the agility of the wheelchair movement," explained Ghovanloo. "In continuous mode, however, the user is allowed to steer the powered wheelchair to the left or right as it is moving forward and backward, thus making it possible to follow a curve."
Each subject completed the course at least twice using each strategy while the researchers recorded the navigation time and number of collisions. Using discrete control, the average speed for the five subjects was 5.2 meters per minute and the average number of collisions was 1.8. Using continuous control, the average speed was 7.7 meters per minute and the average number of collisions was 2.5.
While this initial performance trial only required six tongue commands, the Tongue Drive system can potentially capture a large number of tongue movements, each of which can represent a different user command. The ability to train the system with as many commands as an individual can comfortably remember and having all of the commands available to the user at the same time are significant advantages over the common sip-n-puff device that acts as a simple switch controlled by sucking or blowing through a straw.
Some sip-n-puff users also consider the straw to be a symbol of their disability. Since Tongue Drive users simply wear headphones that are commonly worn to listen to music, the system is more acceptable to potential users.
John Anschutz, manager of the assistive technology program at the Shepherd Center, identified advantages the Tongue Drive system has over the tongue-touch keypad.
"The Tongue Drive system seems to be much more supportable if there were a failure of some component within the system. With the old tongue-touch keypad, if the system went down then the user lost all of the functions of the wheelchair, phone, computer and environmental control," explained Anschutz. "Ghovanloo's approach should be much more repairable should a fault arise, which is critical for systems for which so much function is depended upon."
A future system upgrade will be to move the sensors inside the user's mouth, according to Ghovanloo. This will be an important step for users who are very impaired and cannot reposition the system for best results, according to Anschutz.
"All of the subjects successfully completed the computer and powered wheelchair navigation tasks with their tongues without difficulty, which demonstrates that the Tongue Drive system can potentially provide individuals unable to move their arms and hands with effective control over a wide variety of devices they use in their daily lives," said Ghovanloo.
Georgia Institute of Technology Research News
Spinal cord bridge bypasses injury to restore mobility
The body's spinal cord is like a super highway of nerves. When an injury occurs, the body's policing defenses put up a roadblock in the form of a scar to prevent further injury, but it stops all neural traffic from moving forward.
Aggressive heart pacing may work best in some spinal cord patients
Patients with recurring problems with the heart slowing or stopping after a neck injury damages their cervical spinal cord may need aggressive therapy to avoid further cardiovascular problems and even death, Medical College of Georgia researchers say.
Computer obeys thoughts via Brain-Computer Interface
A research group led by Academy Professor Mikko Sams is developing a brain-computer interface, a device that transforms electrical or magnetic brain signals into commands a computer can understand. Equipment of this kind is necessary. For instance, it enables physically disabled persons to use a computer keyboard. The Brain-Computer Interface, or BCI, allows both physically disabled and healthy persons to direct a computer by merely thinking of certain commands. The On-line Adaptive Brain-Computer Interface project which develops these interfaces is part of the Proactive Computing Research Programme (PROACT), which is funded by the Academy of Finland.
Chemistry & Industry Magazine Issue 2
NEWS
More Quadriplegics Current Events and Quadriplegics News Articles
 |
Wheeling the Deal: The Outrageous Legend of Gordon Zahler, Hollywood's Flashiest Quadriplegic by Chip Jacobs (Author) Paralyzed from the neck down, Gordon Zahler rose from his deathbed to a fast-talking, Hollywood entrepreneur/idea man who traveled the world, lived hard, married, fantasized about water-skiing and chased his dreams to create one of the largest independent postproduction shops in Hollywood. While this is Jacobs story about his coming to grips with his deformed uncle, himself and his mother, the silent victim to Gordon s recklessness, Wheeling the Deal is also a tip of the hat to the man who turned his back on the notion of I can t. |
|
Paraplegic & Quadriplegic Association Of New South Wales Membership by Paraplegic & Quadraplegic Assn | |
 |
101 Reasons to Marry a Quadriplegic by Rhonda Crozier Evatt (Author) Most people would look at Tim and Rhonda Evatt sitting in a restaurant with their two children and feel sorry for them. They would see their sixteen-year-old get out her father’s fork that is bent in a ninety-degree angle and unstrap the safety belt that is placed around her father’s chest as the red-headed six-year-old hops off of the footrests and up into his own chair. The general public would most likely be unable to completely look away. Not just to see how this poor man functions with such a drastic disability, but why he and his wife and children are smiling and laughing. It’s almost as shocking as when they take hands as a family and pray in public before they eat. How can they have such joy in their lives and still love God when he is so disabled? The answer is simple.... |
 |
Quadriplegic Palmer Clip with Pocket by The Wright Stuff For a quadriplegic user. No straps to fasten, yet it provides a firm base for the utensil pocket. Strapless Kydex device that slides onto the hand. Spring action holds cuff in place. Utensil pocket permits effective utensil positioning. Adjust fit with a heat gun. Fits right or left hand. Does not fit built-up handles. Utensils not included. Latex free. |
 |
The Goal Starring: Ryan Parker, Jason Regier, Wendy Duncan, Gale Grove, Jason Coviello Directed By: Darla Rae Studio: Maverick Entertainment Release Date: 10/10/2006 |
 |
2007 Topps Allen & Ginter # 308 Mark Zupan (SP) SHORT PRINT U.S. Quadriplegic Rugby Captain Trading Card by Topps |
 |
Quadriplegics (Live) Anal Mucus (Primary Contributor) |
 |
Another Fine Mess You've Gotten Us Into: The Life and Adventures of a Quad by Robert Prondzinski (Author), Susan M. Carter (Editor), (Cover Design) Anthony Alex Le Tourneau (Editor) Every forty-one minutes another person is added to the list of more than 250,000 Americans living with spinal cord injuries. Many of these injuries will likely leave the person confined to a wheelchair for the rest of his or her life. These are just ordinary people living ordinary lives and in one split second their lives are changed forever. Picture yourself as a typical healthy and active teenager one minute, and a minute later being confined to a bed or wheelchair for the rest of your life. Or imagine you are a parent who has just been told by a doctor that your son or daughter will never walk again. Close your eyes and take five minutes to imagine what the rest of your life would be like. Bob Prondzinski and his parents didn't have to imagine it. They lived it. Another Fine Mess... |
 |
Joni Starring: Joni |
|
It's Good to Be Alive Jack Rushton may be the only quadriplegic comedian in the world, and he uses his keen sense of humor to motivate and delight everyone. This is a true story of a man who refused to give up. It is the heart changing tale of faith, family and friends who show that even in extremely challenging circumstances, one can always say, "It is good to be alive." |
| © 2009 BrightSurf.com |