Patent ID: 7715276

Claim:
A system for detecting a presence of a body at an intersection between first and second paths, the system comprising: an ultrasound sensor array for defining a detecting zone at the intersection of the first and second paths and for emitting a first trigger signal when the body is in the detecting zone; the ultrasound sensor array including a first sensor assembly that creates a first acoustic line over the intersection; the first acoustic line intersecting a direction defined by the first path; the first trigger signal being emitted when the first acoustic line is cut; wherein the sensor array including at least one second sensor assembly that emits a first ultrasound floating cone towards a portion of the intersection; the first trigger signal being further emitted when the body contacts the first ultrasound floating cone; and a controller coupled to the ultrasound sensor array for receiving the first trigger signal and for emitting an alarm signal indicative of the first trigger signal.