Optimizing Assisted Communication Devices for Children With Motor Impairments Using a Model of Information Rate and Channel Capacity

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00352326
Recruitment Status : Completed
First Posted : July 14, 2006
Last Update Posted : May 19, 2017
Information provided by (Responsible Party):
Terence Sanger, University of Southern California

Brief Summary:
For children who depend on devices to communicate, the rate of communication is a primary determinant of success. For children with motor impairments, the rate of communication may be limited by inability to contact buttons or cells rapidly or accurately. It is therefore essential to know how to adjust the device interface in order to maximize each child's rate of communication. The optimal rate of communication is determined by the Channel Capacity, which is the maximum value of the Information Rate for all possible keyboard button or cell layouts for the communication device. We construct a mathematical model for the information rate based on the relationship between movement time and the number of buttons per screen, the size of the buttons, and the length of a sequence of buttons that must be pressed to communicate each word in the vocabulary. We measure the parameters of the model using a custom-programmed touch-screen interface.

Condition or disease Intervention/treatment Phase
Cerebral Palsy Device: reprogramming assisted communication device interface Not Applicable

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 29 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Optimizing Assisted Communication Devices for Children With Motor Impairments Using a Model of Information Rate and Channel Capacity
Study Start Date : January 2006
Actual Primary Completion Date : December 2014
Actual Study Completion Date : December 2014

Arm Intervention/treatment
Experimental: Children (with dystonia and controls)

Participants sat in a chair or their own wheelchair in front of a table whose surface height was adjusted at the midpoint between the hip and the Xiphoid process. They placed the hand that was not used for the task on their lap.

An iPad® (Apple Inc, Cupertino, California) was located on the table in portrait mode in front of the participants at a distance that ranged between 40 and 55 cm. An adjustable metal bookstand supported the iPad® to allow the participants a comfortable screen view. The size of the screen was 19.5 × 14.6 cm. Custom software was developed for the experimental task (XCode 3.2 development environment, iOS 4.2 operating system; Apple Inc, Cupertino, California).

Device: reprogramming assisted communication device interface
The subjects were required to touch targets on the iPad® screen with the index finger of their preferred (less-affected) arm. The experimental task consisted of 180 targets divided in 4 blocks: 45 targets each block with a 1-minute interval between trials to avoid fatigue. Targets appeared at 1 of 9 different locations on the screen, and subjects moved their finger sequentially from one target to the next.

Information from the National Library of Medicine

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Ages Eligible for Study:   5 Years to 25 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:- Use of Dynavox ability to follow two-step commands impairment in arm function

Exclusion Criteria:- increased risks of study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00352326

United States, California
Stanford University School of Medicine
Stanford, California, United States, 94305
Sponsors and Collaborators
University of Southern California
Principal Investigator: Terence D. Sanger Stanford University

Responsible Party: Terence Sanger, Associate Professor, University of Southern California Identifier: NCT00352326     History of Changes
Other Study ID Numbers: FITTS PILOT
First Posted: July 14, 2006    Key Record Dates
Last Update Posted: May 19, 2017
Last Verified: May 2017

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:
Cerebral Palsy
Brain Damage, Chronic
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases