Invention could enable the paralyzed to control machines via head motions.

A class of inertial- sensor systems with drift compensation has been invented for use in measuring the orientations of human heads (and perhaps other, similarly sized objects). These systems can be designed to overcome some of the limitations of prior orientation- measuring systems that are based, variously, on magnetic, optical, mechanical-linkage, and acoustical principles. The orientation signals generated by the systems of this invention could be used for diverse purposes, including controlling head-orientation-dependent “virtual reality” visual displays or enabling persons whose limbs are paralyzed to control machinery by means of head motions.