In this paper, two kinematic structures with optimized spherical wrist modules are proposed for the practice of tele-echography through a new slave holder robot for a remote ultrasound diagnostic application. The medical gestures, performed during an ultrasound examination, are analyzed using two different techniques. The results are used in the definition of the robot kinematic structure specifications. The proposed medical robot is formed by two modules, a spherical displacement orientation module and a translation module, to control the interaction force between the probe and the patient. Multicriteria optimization is proposed and is applied to two spherical structures: one serial and one parallel. Workspace size and kinematic performance, in addition to the index of compactness of the manipulator, are considered in the optimization. The efficiency of the optimized kinematic structures across their workspace is studied and compared to determine which one is more adapted to the tele-echography application.