Rear cab - vertical restraints?

Hey gang - I have a rig for personal use only (not for hire). There are times I'd like to take my family on a ride with me. The passenger seat is no problem. But someone has to sit in the back / bed area. And the only straps are the belts meant to hold you in place while sleeping.

I'm wondering if anyone knows of a vertical restraint system for the beds in the back. Something where a rear-bed passenger can be sitting up on the bed and still be strapped in safely from the shoulders down.

Is there anything like that out on the market? Something to safely secure passengers in the bed area while sitting?

 

It's really not about the border patrol so much as for safety. I want to make sure my child is safely restrained back there as best as possible.