This device may be preset and installed in such a way that it is adjusted and accessible for a person to operate. However, it requires a person to have certain level of physical and cognitive performance skills to be able use this device successfully and benefit from use of it.
Motor Skills (mobility: reach keyboard, coordination: manipulate and perform isolated finger movement, strength and effort: calibrate finger movement and strength, energy: to perform typing) (AOTA, 2002)
Process Skills (Knowledge, Inquire, Initiate, Continue, Sequence, Notice, Responds) (AOTA, 2002)
Communication/Interaction Skills (information exchange) (AOTA, 2002)
Required Client Factors: Body Functions: Mental Functions (orientation, energy and drive, attention, thought, mental function of language, motor planning), Sensory Functions (seeing, touch), Neuromusculoskeletal (mobility of joint, mobility of bone, muscle tone, control of voluntary movement). Body Structures: nervous system, eyes, ears, structures related to movement (fine motor activity required for typing).

The DynaWrite device provides the voice and speech body functions and improves person’s communication and interaction skills.

This product is available from Dynavox Systems LLC (formerly known as Sentient Systems Technology, Inc.), a division of Sunrise Medical:
2100 Wharton Street, Suite 400
Pittsburgh, Pennsylvania 15203
United States
Telephone: 800-344-1778 or 412-381-4883.
Fax: 412-381-5241.
Web: http://www.dynavoxsys.com.
Email: contact@dynavoxsys.com.
Price varies from $1100 (used from eBay) to $3749 (new from dynavox systems)

More Info on http://www.dynavoxtech.com/files/device_tutorials/DynaWrite/index.html