Hello,
I know some here have mentioned pain pumps.
You might try looking on these forums

Chronic pain - http://neurotalk.psychcentral.com/forum10.html

Spinal - http://neurotalk.psychcentral.com/forum22.html

RSD - http://neurotalk.psychcentral.com/forum21.html

TOS - {I think only 1 has pump here} - http://neurotalk.psychcentral.com/forum24.html

and the forum wide search link - http://neurotalk.psychcentral.com/search.php