What's the bend radius on the pivot points?
I use some specialty cables for robot automation. They are rated at 100,000,000 moves. I can see if any have the capacity for hdbaset, but minimum bend radius would be the starting point.
Fiberoptic would be your other option; again, depending on the bend radius:
[Link: gore.com]Gore's Fiber Optic Core Survives More Than 50 Million Rolling Flex Cycles