Health tools for smart phones that monitor blood sugar levels or work as stethoscopes may face the same scrutiny from regulators as heart stents or ultrasound machines. These mobile medical applications pose a potential risk and may have to meet Food and Drug Administration medical-device quality standards before they can be sold for use with smart phones such as Apple’s iPhone, according to draft guidelines issued. The agency is focusing on applications that directly diagnose or treat conditions such as diabetes or that transform the smart phone into a medical device. The regulations mark the first ground rules for a market that Ilkka Korhonen, a former senior manager of Nokia Corp.’s wellness business program, estimates may climb ninefold to $6 billion in 2015. US regulators propose to standardise the design, production and distribution of the applications to assure the products are safe and effective. Stents and ultrasound machines typically must undergo a review that requires manufacturers to demonstrate products are at least as safe and effective as legally marketed devices for the same use. Most applications will be subjected to the lightest class of FDA regulation and won’t have to meet oversight such as the review known as a 510(k) program. The guidelines don’t affect design specifications for companies such as Apple and Verizon Communications Inc. that provide smart phones, or makers of operating systems such as Google’s Android platform, which powers Motorola’s Droid handset.