This was a major milestone in force feedback technology and derivatives of this design are still seen today. Goertz gradually became aware of the necessity of haptic senses for manipulating delicate objects and used force-feedback systems to improve the deftness of the human-machine combination. Through incorporating the principles of cybernetics Goertz was able to also construct the first electrical master-slave manipulator system, and by 1954 a modified version of the master-slave manipulator (Model 8) began commercial production. In order to create accurate master-slave manipulator devices, it was necessary for Goertz to develop several principles, all of which are applicable to our own contemporary robotic surgical systems. The principles are as follows. The motion of the slave arm must possess six independent degrees of freedom, three of translation and three of rotation to position gripping devices, and a tong squeeze motion to grip items. The motion of the slave arm must be coupled to the master arms that the position and the direction of the two arms correspond to. The coupling of the two arms must be bilateral and this means that forces at the slave end must be reflected at the master end and displacements produced at the slave end must be able to produce a displacement at the master end, with the slave arm being able to align itself in response to the constraints imposed by the task being done. Awards Goertz was the recipient of the Edward Longstreth medal at the Franklin Institute in Philadelphia, Pennsylvania in 1967. He also received the Radiation Industry award from the American Nuclear Society in 1969. In 1985 the American Nuclear Society established the "Ray Goertz Award" to recognize and honor its members who have made outstanding contributions to the field of remote technology. Personal life Goertz married Helen Boula on September 2, 1950, in Cook, Illinois. Together they had three children: Alan, Jean, and Linda. Goertz died on June 4, 1970, at the age of 55 in Downers Grove, Illinois. References 1915 births 1970 deaths American roboticists People from Sedgwick County, Kansas