How can I fix my corrupted iPod?

Okay, so a while back my iPod started having problems. One day I plugged it in and my computer said that it was "corrupted", and that I need to restore it. So I clicked the "restore" button and my iPod was restored back to factory settings, and my iTunes was loaded again on to my iPod and everything was fine. A few weeks later this exact thing happened again, and so I did the exact same thing. Except this time after I clicked on "restore" and my iPod has finished restarting, nothing happened. My computer won't recognize my iPod and when I disconnect it, my iPod is empty. If I disconnect it and plug it in again, it says it's corrupted again and the whole process starts over again. I've tried restarting my iPod by switching the hold switch on and off and pressing down menu and select, but it doesn't help. What's wrong with my iPod, and how can I fix it?