A small Roseville company has gotten approval to sell an implantable device that helps people lose weight by using electric signals to convince the brain that the body isn't hungry.

EnteroMedics Inc.'s Maestro Rechargeable System works by sending 5,000 pulses per second to the vagus nerve, blocking signals between the stomach and the brain. The result is that the stomach feels fuller by taking longer to digest food and the brain doesn't cause it to expand in anticipation of a meal.

The Food and Drug Administration (FDA) on Wednesday approved the device, which is expected to be available later this year for adult patients who have struggled with other weight-loss alternatives. The obesity-care community cheered the news as a signal that the FDA was starting to put a strong focus on a widespread condition with limited treatment options.

"This therapy is novel, and that is encouraging because when one is proven to be safe and effective … that encourages other innovators to explore other treatment avenues," said Martin Binks, a nutrition science professor and spokesman for the Obesity Society in Silver Spring, Md. "We are looking at a glimpse of a better future to provide a breadth of options to patients who are struggling to manage their obesity."

About one in three adults in the U.S. had obesity in 2012, compared with about one in five just 20 years earlier, according to the latest data published by the Centers for Disease Control and Prevention. The American Medical Association recently voted to classify obesity as a disease.

"This is a market that really needs more technology or more procedures to help battle the obesity epidemic. All the physicians we deal with say they need more tools in their tool bag," EnteroMedics chief operating officer Greg Lea said.

"We believe we are very well-positioned in an underserved marketplace for a commercial launch."

The FDA has approved weight-loss drugs in recent years, including an injectable drug called Saxenda from Novo Nordisk. While the Maestro is the first medical device for obesity in seven years, and the first that targets a neural pathway, several companies are developing other neurostimulation devices for obesity.

Implanted surgically in the abdominal area, EnteroMedics' device looks similar to a cardiac pacemaker, using batteries to generate charges that travel along sophisticated wires called leads into the body. But where pacemaker leads stimulate heart muscles, the Maestro's target trunks of the primary nerve regulating the digestive system. The rechargeable device is considered a "reversible" weight-loss therapy, because it doesn't surgically alter the digestive system or create barriers to food absorption.

The device will cost between $10,000 and $15,000, and the total cost of an outpatient procedure will range between $20,000 and $25,000 — midway in price between a gastric band and bypass surgery.

The device is approved for patients 18 and older who, in the past five years, haven't been able to drop pounds through a supervised weight-management program. Eligible patients must have a body mass index between 40 and 45, (or 247 to 278 pounds for a person who is 5-foot-6 inches tall) but people with BMIs of 35 or more are eligible if they have a related condition such as high blood pressure or high cholesterol.

A recent clinical trial found that people with the device lost significant weight — but so did people in a control group of the same study.

A randomized placebo-controlled study sponsored by the company found just more than half of the patients using the device lost at least 20 percent of their excess weight within a year — a result that Binks said was noteworthy, since any weight loss of 5 percent or more is considered significant. But the study's control group members, who had devices implanted but not switched on, also lost weight. The experimental group lost only 8.5 percent more weight than placebo.

An FDA panel eventually concluded that weight loss with the device appeared to be sustained after 18 months, and therefore the benefits of the Maestro outweighed its risks. The company will be required to follow 100 patients over five years and submit their data for a future safety and effectiveness review.

EnteroMedics, a one-product company with no revenue that reported a $5.7 million loss during the three months ended Sept. 30, intends to launch the Maestro in the U.S. on its own. When asked whether the company would entertain a buyout offer from a bigger device company, Lea said that while it's not the plan, directors would have to consider any offer.

"If the right partner would come along, we'd certainly look at what's best for our shareholders," he said.