A method and device for training persons to remain within a safety zone. An emitter establishes a safety zone that is not to be exceeded by the person, and an adjuster may be operatively connected to the emitter to adjust the size and position of the safety zone. A sensor is placed away from the emitter...http://www.google.de/patents/US7845948?utm_source=gb-gplus-sharePatent US7845948 - Training method and device for teaching a trainee to remain within a safety zone
