Patent ID: 7541934

Claim:
A method of monitoring an object with respect to a potential fall condition, comprising: observing a detection area with an optical detector; determining, based on at least one image of the detection area, that the object is in an upright condition in the detection area; by determining an angle between the object and a vertical direction and that the angle is below 20 degrees; by transforming foot image coordinates (uf, vf) of a foot portion of the object into foot room coordinates (X f , Y f =0, Z f ); adding a length ΔY to a vertical coordinate of the foot room coordinates; transforming at least the vertical coordinate to form top image coordinates (uh, Vh), whereby the vertical direction is given by a vector, between the foot image coordinates (uf, Vt) and the top image coordinates (uh, vh); and determining an angle between said vector and the object; waiting for a predetermined time period; and emitting an alarm after said predetermined time period.