Well, now another researcher is working on a smart bra design, only this one is for detecting breast cancer. The UK researchers are using
a series of microwave antennae to detect temperature changes in the breast that point to early stage breast cancer.This is known as thermography, and the hope is that the temperature change will spot tumours before they grow and spread to the surrounding tissue. The microwaves are passive - the same sort used in astronomy or in detecting submarines - not harmful to individuals (which I'd hope wouldn't have to be said, but sometimes...) - and the bra itself would chime a little alarm when wearers needed to see a doctor due to potentially dangerous changes.
Now granted, it's still in the design stage, and there are concerns over whether or not the alarm would be triggered by false positives (nonmalignant changes in breast tissue, for example), or if it would be truly effective in catching cancerous growths before they advanced far enough to be seen by a mammogram or felt during a breast exam. And beyond the practical functionality, there's a cost issue.
While this isn't addressed in the articles I've read on the subject, I would be concerned about the exclusivity something like this would naturally have. I can't imagine it would be an inexpensive device to wear, so it would lock out a large segment of the population for whom it might be most beneficial - those who can't afford yearly exams and screenings. But then again, given the recent study that showed how many cases of cancer radiologists miss, it would still be a good thing - just for a more limited group.