Abstract: A medical robotic system includes a viewer for displaying an image of a work site, a gaze tracker for tracking a gaze point of a user on the viewer, and a processor. The processor is configured to: draw an area or volume defining shape, overlaid on the image of the work site, in a position determined by the gaze tracker; assign a fixed virtual constraint to the shape and constrain movement of a robotic tool according to the fixed virtual constraint; receive a user selected action command selecting an image of patient anatomy; and superimpose the selected image of the patient anatomy over the image of the work site within the shape. The selected image of the patient anatomy is registered to the image of the work site.

Abstract: A method of calibrating a surface measurement instrument includes rotating a work piece having an undulating surface on a turntable of a metrological apparatus; measuring the surface of the work piece at a plurality of rotational positions; analyzing the results of the measurement to determine parameters describing an error causing characteristic of the metrological apparatus; and using the determined parameters to correct measurement data for the error causing characteristic of the metrological apparatus.

Abstract: A method of calibrating a surface measurement instrument includes rotating a work piece having an undulating surface on a turntable of a metrological apparatus; measuring the surface of the work piece at a plurality of rotational positions; analysing the results of the measurement to determine parameters describing an error causing characteristic of the metrological apparatus; and using the determined parameters to correct measurement data for the error causing characteristic of the metrological apparatus.

Abstract: A system for crushing a wall of rock comprising a first device, such as a track hoe, for moving with at least two degrees of freedom, a second device, such as an articulating boom, secured to and moving with the first device for moving with at least two degrees of freedom, one of the two degrees of freedom of the second device being different from the two degrees of freedom of the first device. A rotating stone cutting mechanism is secured to the second device, the stone cutting mechanism comprising a rotating drum having a plurality of tooth holders on the surface thereof in a helical array relative to the axis of the drum, each of the tooth holders having a very hard tooth, preferably of a refractory carbide, releasably secured thereto. A motive structure causes rotation of the drum about its axis. The motive structure includes a motor, preferably hydraulic, a sprocket driven by the motor, a chain and a second sprocket coupled to the drum.

Abstract: A metrological apparatus for measuring form and texture of a surface employs an inductive transducer producing an AC gauge signal, and a tracking AC analogue to digital converter. In order to avoid errors in the output signal at a relatively high speed of traverse of the surface due to a non-flat frequency response of the converter, the output signal is processed by a digital filter to provide a combined frequency response which is flat over a desired range. In order to avoid errors in the output signal due to non-linearity of the transducer, a square or cubic correction is applied to the signal. A method calibrating the apparatus to obtain coefficients for the square and cube terms in the correction process is also described.