Tracking obscured object

I am having trouble with at track. I have to replace a logo on the front of a hospital bed, moving camera cranes. Someone walks in front of the bed and crosses the shot. This is were it goes wrong. The whole front of the bed is blocked fro a few frames. Lots of motion blur on the person passing… Any help on work flow would be much appreciated. I have been working on this for a day and a half and of course my deadline is looming.