We present in this paper an assistive technology of communication and command for quadriplegics. To carry out this assistive technology, a user centered design approach with the patient, his occupational therapists and his family was conducted. Various iterative versions of the prototype have been defined by means of the SOKEYTO platform to meet the needs and the abilities of the quadriplegic person. Options carried out and consecutive choice will be reported as well the difficulties to implement. The assistive technology was used by one quadriplegic person. A qualitative evaluation is also reported.