#$%^&*AU2019210499A120190815.pdf#####INPUT DEVICE ASSEMBLIES FOR ROBOTIC SURGICAL SYSTEMS ABSTRACT A reaction torque transducer (68) for mounting a motor (62) of an instrument drive unit includes a motor plate (70), a mounting plate (80), and a flex ring (90). The motor plate (70) is fixed to the motor (62) and the mounting plate (80) is fixed to a fixed structure. The flex ring (90) is positioned between the motor plate (70) and the mounting plate (80). The flex ring (90) includes a body (92) having a first end (92a) and a second end (92b) that are moveable relative to one another. The first end (92a) of the body (92) is fixed to the motor plate (70) and the second end (92b) of the body (92) is fixed to the mounting plate (80). The body (92) is configured to flex in response to the first and second ends (92a, 92b) moving with respect to one another. A strain gauge (110) is positioned on the body (92) of the flex ring (90) and is configured to measure flexation of the body (92).
