Yeah, a stethoscope and a sty.. styg..Sphyg...sp...er.. blood pressure meter are used by a nurse or a tech, too. Trust me, I'm no Tom Cruise fan, but I highly doubt he would do anything that could risk the life of his little one. Just another case of "got the money."
I'm no doctor, but sonograms are simply high frequency sound waves. I'd think the pressure applied to her abdomen would be more dangerous than the machine itself, unless of course, they were taking pictures in the bathtub. Hell, they sell "hear your baby" microphones that do almost the same thing at Babies 'R Us. I can understand folks being upset if he had purchased a bone saw and a morphine pump for his sick grandmother, but I don't think this is much of anything...
I really doubt this is a replacement for medical care. Just something to do when he's bored. You know, between hollywood parties, Lamborghini shopping, and banging the hell out of Katie Homes.
-Jeff