2.1. Apparatus
BRAIN
The maintenance tasks were performed on a piston pump subsystem. This piston pump is part of the “GUNT” Practice Line for assembly, maintenance, and repair, which is designed for students and technicians’ training (set: MT 184, Assembly & Maintenance Exercise: Piston Pump). A screwdriver, a wrench, a soft hammer, a jig, and a bearing puller were all needed to complete the tasks on the piston pump. Two instruction methods (Microsoft HoloLens and paper instructions) were used to guide the participants to complete the maintenance tasks. The maintenance instructions for the two tasks were communicated via the Microsoft HoloLens AR system. The paper instruction manuals for the two tasks were developed based on the manual provided by the manufacturer (Gunt technology Ltd., Barsbüttel, Germany). A Live Amp wireless amplifier (Brain Products, GmbH, Gilching, Germany) with 32 channels (weighing 60 g) was used for amplifying and digitizing EEG signals. To hold the EEG electrodes, a black sub-inion cap (EASYCAP, Brain Products GmbH, Gilching, Germany) with an integrated chin made of soft, high-comfort fabric was used. A brain vision recorder system (Brain Products GmbH, Gilching, Germany) was used for recording EEG signals.