When I got up to the guy who looks at my ticket, in the security line, I start by telling him I can't get a regular screening as I have a medical implant. Then after I take my shoes off and stick all my stuff in the bins prior to going through Xray, I walk up to the Xray walkthough machine and then refuse to go through the Xray, telling them I can't as I have a medical implant and show them my card. I also make sure to tell them I can't be "wanded" either. What they do is have me stand in the body scanner (smile as you're getting your picture taken) and then they sometimes take me aside and do a pat down. Make sure you allow extra time to go through security as it does add about 10-15 mins. to do it this way. Another time all I got was a pat down, no body scanner, so I think it depends upon the airport. Just make sure you give them an explanation of why you're refusing to walk through the normal Xray machine and they'll have an alternative for you. Seems it's no big deal these days. Good luck!