The devices, which can cost several thousand dollars, use rinses, dyes and different types of lights to detect abnormal cells.
Once users accept the devices, which can include Bluetooth printers and cellphones, they are wirelessly linked to the PC.
They are packed with sensors, particularly accelerometers and GPS tracking devices, which can record movement and exercise.
But now doctors believe that continuous-flow devices, which can be smaller and last longer, may function well.
The idea is that consumers can control the devices, which can communicate wirelessly, with their smartphones, tablets or televisions.
Nanocarriers are small enough drug delivery devices which can serve this purpose.
These systems consist of large numbers of storage devices which can provide high rates of data transfer.
It applies mainly to electronic devices, which can mean everything from cars to fighter jets and drones.
These methods pose severe limitations in the development of devices which can operate in normal ambient conditions.
But the devices, which can be expensive, remain largely unproven and are not usually covered by the government or private insurance plans.
The F.D.A. classifies hair-removal lasers as prescription devices, which can be sold only to physicians, dentists and other "licensed practitioners," an agency spokeswoman said.
