Abstract: A capacitive touch switch suitable for use in areas with high environmental and electrical contamination employs a complex excitation signal that is demodulated to better distinguish it from environmental effects. Improved discrimination allows these sensed signals to be offset against a signal developed by a reference electrode to allow the system to operate robustly with contamination on the electrodes that would otherwise trigger or obscure pulses.

Abstract: A capacitive touch switch suitable for use in areas with high environmental and electrical contamination employs a complex excitation signal that is demodulated to better distinguish it from environmental effects. Improved discrimination allows these sensed signals to be offset against a signal developed by a reference electrode to allow the system to operate robustly with contamination on the electrodes that would otherwise trigger or obscure pulses.

Abstract: A blood centrifuge with a drive assembly for transmitting an input rotation speed to a rotor with a sample reservoir at a desired rotation ratio. The drive assembly includes a base and an outer shell mounted to the base to rotate at an input rate. A bottom pulley is rigidly mounted to the base and attached to the outer shell with bearings. A top pulley is mounted to a center shaft of the outer shell to rotate with the outer shell about the central axis of the centrifuge. An internal drive belt is provided to transmit the rotation to the top pulley via a pair of transversely mounted idler pulleys that rotate with the outer shell. The top pulley is thus rotated at twice the input rate but in the same direction. A rotor assembly with the sample reservoir is attached to the top pulley to separate blood components.