A trocar assembly including a low-profile retractable shield deployable adjacent to a cutting element with a cross-sectional area which is small relative to the total cross-section of the assembly. or more, particularly exceeding 700 C. The processor is configured to control a spin velocity of the gyroscopic mechanism based on receiving an alert of an incoming call or message, or detecting a fall. The selection circuit retains a cumulative value whose each digit is a cumulative result in each bit of data which is already written in the memory cells. In other embodiments, instead of converting the mouse message into a command, the message hook procedure displays a graphical user interface based on the focus application and the mouse message. In an embodiment, the method includes determining a location of the visual defect, identifying a plurality of sub-pixels neighboring the visual defect and utilizing contrast sensitivity functions and visual masking characteristics of a human visual system to optimize adjustments to the plurality of neighboring sub-pixels to mask the visual defect.