Protecting USB Port on Computer

So I just destroyed my Macbook Pro by unintentionally putting 15 V through my Arduino analog port. While I know that one shouldn't change wiring while powered, this was still a bit of a surprise (not to mention a huge bummer!). I now understand a bunch of rules for avoiding this, but I'd like to be doubly safe in the future to avoid frying another laptop. Is anyone aware of a failsafe way to protect one's USB ports? I've tried looking for something like a surge protector for a USB port without any luck.

Thanks for any suggestions!

https://www.google.com/search?q=usb+optical+isolation+hub

cheaper route

philips/nxp

http://www.nxp.com/documents/application_note/AN10753.pdf

siemens/infineon

http://www.infineon.com/dgdl?folderId=db3a30431441fb5d01146ec76de80910&fileId=db3a3043372d5cc801374a7ea80c3a79

Würth Elektronik

http://www.we-online.com/web/en/index.php/show/media/07_electronic_components/download_center_1/application_notes_berichte/The_Protection_of_USB_20_Applications.pdf

few way might save u macbook, I hope;-

  1. resetting the System Management Controller (SMC) ( search apple support forum)
  2. resetting the NVRAM ( search apple support forum)

if above failed, use Multimeter measure resistance of USB port.

Standard USB port:

Apple IPad/Iphone USB port:

if short, most case TVS diode burned. remove it from mother board, machine will be fixed, but no more protection. U need to be handy man.