A wearable smart device currently in development could one day keep an eye on smokers as they light up and decide whether they need assistance in their goals to quit.

The necklace, called SmokeMon, currently consists of a rather simple blue box that hides heat-sensing technology, though in time it could be reduced to suit a stylish pendant that satisfies just about any fashion taste.

Unobtrusive and lacking a means of identifying users or those around them, the technology aims to meet privacy and stigma concerns, with early user testing already returning a positive response.

If you smoke, you likely already know that your habit not only puts your own health at risk, it can affect the health of those around you, potentially for generations to come.

Given the impact cigarette smoking has on public health, there are now plenty of scientifically-backed methods for kicking the habit. As experts learn more about the behaviors of smokers who are keen to give it up, they can continue to shape their advice on how to proceed.

Development of the monitoring device is being led by researchers at Northwestern University in the US with the goal of helping smokers quit by understanding their smoking habits that might signal a return to old ways.

"For many people who attempt to quit smoking, a slip is one or two cigarettes or even a single puff. But a slip is not the same as a relapse (going back to smoking regularly)," says senior author Nabil Alshurafa, a behavioral and computer scientist from Northwestern University.

"A person can learn from slips, by gaining awareness that they did not fail, they just had a temporary setback. To avoid a relapse, we can then begin to shift their focus on how we handle their triggers and deal with cravings."

The key advantage of this new technology is that it detects smoking behavior more accurately and discreetly than other prototype devices.

The battery-operated device uses thermal sensors to detect heat radiating from the tip of a lit cigarette and collect information about each cigarette. These measurements include details like how many puffs were taken, the amount of smoke inhaled, and time between puffs.

Nineteen people took part in the study and the scientists observed their smoking behavior while wearing the device in 115 sessions, both in a laboratory setting and in real-world conditions. Testing the device outside of the lab allowed the team to determine if smokers were uncomfortable wearing the necklace in public and if they reported any reactions from bystanders.

The researchers used a machine learning algorithm to process the data, and compared SmokeMon's performance and usability to an existing "gold-standard" device for monitoring smoking behavior. Called CReSS pocket, it requires users to insert a cigarette into one end and inhale through a mouthpiece on the other.

The measurements recorded by SmokeMon showed similar accuracy compared to those of the CReSS pocket device, and the participant responses in post-experiment questionnaires are promising.

Most participants reported it did not interfere with their daily life or smoking behavior, and they were not concerned about discomfort or invasion of privacy to themselves or those around them.

One participant stated "I had one friend who inquired about what the device was recording, and he seemed satisfied when I told him it wasn't recording audio or video."

The researchers argue their results suggest "considerable promise" in using thermal cameras to assist smoking cessation, but noted they needed more data. There are also limitations, they note, such as how performance could be affected when smokers are in cold surroundings.

To facilitate future research that aims to explain or evaluate smoking behavior, the authors have provided an open-source data-processing platform.

"Now we can begin to test the effectiveness of this device in improving the success rate of smoking cessation programs by preventing relapse in smokers who are planning to quit," Alshurafa says.

"We will be able to test whether real-time feedback and interventions can be more effective than usual care. "

The study has been published in Proceedings of the ACM on Interactive, Mobile, Wearable, and Ubiquitous Technologies.