A method for tracking position of a feature in a subject is provided comprising operating a CT scanner to generate and display CT images of a volume within the subject and operating the CT scanner to generate projection X-Ray images of the volume. An input shaft supported in the housing drives a variable-displacement hydraulic pump, the pump fluidly coupled to a fixed-displacement hydraulic motor, and the motor drivingly connected through the speed reducing gearing to an output axle shaft. The machine is operative to authenticate the key or certificate prior to granting a user permission to install, run, andor configure the software. Transmission of the request to the endpoint is initiated. According to the invention, the timepiece movement further includes a device preventing adhesion of said balance spring against said bar including a surface decreasing means formed on the bar for limiting the contact surface when the faces of said balance spring and of said bar touch each other. If the user is authenticated, an authentication token is received from the biometric device and sent to a remote device, which initiates the secure financial transaction.