A system and method for collecting and testing data at a patient point of care location via a first device, such as a sample cartridge adapted to engage a first device, such as a personal digital assistant incorporating a wireless communication module to communicate collected data to a second device, such as a healthcare workers personal PDA located beyond a contamination radius about a patient. Steering cylinders of the steering mechanism extend and contract in response to an operation of a steering handle provided in a cab to perform the steering operation of the front wheels. The round robins are arranged in a multi-stage tree link configuration, and the queues are distributed under those of the round robins which are in the lowest order stage. The inner circumference of the second bulging portion has a first spherical recess 23 corresponding to the first bulging portion.