Assistive technology is defined in the IDEA 2004 as:

Any item, piece of equipment or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve the functional capabilities of children with disabilities.  It is also any service that directly assists a child with a disability in the selection, acquisition, and use of an assistive technology device. 

(Authority 20 U.S.C. 1401(1))