An optical system can include a curved light sensor and an optical system positioned in front of the curved light sensor. Also included in the electronic casino gaming system are a non-volatile RAM, a mass storage unit, a disk subsystem, and a PCI bus. Accordingly, by evenly agitating ice cream particles at upper and lower portions of the canister, the bead-shaped ice cream particles are prevented from attaching to each other. The detection system, which is required for each probe tip, thereby acquires a very simple configuration of few commercially available components. The implantable device may be a cardiac pacemaker, a spinal cord stimulator, a neurostimulation system, an intrathecal drug pump for delivery of medicants into the spinal fluid, and infusion pump for delivery of chemotherapeutics andor anti-spasmodics, an insulin pump, an osmotic pump, and a heparin pump. Instrument guide tube may swivel about the alignment stand via a rotational coupling, or may be one of two fixed instrument guide tubes.