Go deep inside a human lung, where a suspicious mass may be cancer.

Above you, broad airways offer cancer doctors' probes relatively easy access to snip out samples and test them for cancer. But down below, an explosion of tiny airways shoots off in every direction, concealing the potential tumor somewhere among a maze of tens of thousands of branches in the lung's lower half.

Several methods exist to reach lumps deep inside the lung, but most involve slicing through tissue to get there. That can be bad. Open-chest surgery, even minimally invasive surgical procedures, can collapse a lung — a risk that discourages some people from getting tests to find out if they have cancer.

Yet lung cancer keeps killing Americans in large numbers. About 160,000 died from the disease last year, more than cancers of the colon, breast and prostate combined.

Tucked away in a Plymouth business park along Interstate 494, a unit of Covidien Inc. is perfecting the latest iteration of what it says is a technology that could boost lung-cancer survival rates by taking the bloody incisions out of lung biopsies.

The superDimension Navigation system uses advanced imaging and computer modeling to help a doctor guide a skinny probe through existing airways to within millimeters of a lesion, without boring holes or cutting skin. The procedure is called electromagnetic navigation bronoscopy, or ENB.

"In the past, patients used to go to surgery, and their big chunk of lung tissue comes out, and then they see it's not cancer. People used to get surgery for not a good reason," said Dr. Erhan Dincer, a lung-cancer doctor at the University of Minnesota Medical Center. "With this, we can do a biopsy of the lung, and see, no this is not lung cancer, without surgery."

SuperDimension was founded in Israel and established U.S. operations on Cheshire Lane in Plymouth. The company was bought for about $300 million in 2012 by global health care supplier Covidien, which is now in the process of merging operations with Medtronic through a $43 billion acquisition expected to close early this year.

While older versions of the superDimension ENB technology improved on the system's technical operation, Covidien engineers have worked mainly to improve its user interface, which now includes slick 3-D graphics and a GPS-like navigation system, offering turn-by-turn directions for how to park next to a lesion.

"Ease of use becomes really important. It becomes an indirect determinant of patient outcomes," said Chuck Brynelsen, president of the Covidien early technology division that includes superDimension. "By virtue of having a safer alternative, doctors are more likely to go in and do a diagnosis earlier."

The process starts with the patient getting a detailed chest scan that yields more than 300 separate cross-section images of the lungs. A computer analyzes those images and creates a three-dimensional model of each lung's unique airways, down to the smallest level. After some calibration work, doctors pinpoint the exact dimensions of each suspicious lesion, and the computer figures out the precise sequence of ups, downs, lefts and rights that will guide the probe to its target.

"There are thousands of airways, so we need a road map," said Michele Bazinet-Bossert, a vice president with the company, who helps train doctors on the technology.

The patient may get just local anesthesia before the bronchoscope is inserted through the mouth and into the lungs, quickly passing through the wide upper airways that have long been accessible by scope, and into the thicket of tiny tunnels that are impossible to navigate without computer assistance. When the goal is reached, the scope can be withdrawn, leaving just a tube through which other tools can be passed to snip out samples and leave biological markers for future procedures.

Brynelsen said that ideally a pathologist is involved in the procedure to offer a quick diagnosis, avoiding the infamously painful several-day wait to find out whether a person has lung cancer. "We really think this should be the standard of care," he said.

Twitter: @_JoeCarlson