A trial that involved primary school pupils wearing a head-mounted device that monitored their attention spans has been halted in China amid parents’ privacy concerns and fears they could be used to control the children, local media have reported.

The device monitors brainwaves and sent data to the computer system at Xiaoshun central primary School in Jinhua City, Zhejiang province, and some data was shared with parents, according to state-run newspaper Beijing News.

It also quoted a teacher as saying the experiment had been going for a year and that data was also transferred to a company server. Students had reported no side effects from the device, the teacher named Zhang said, and the full data was not shared with parents.

“All we are doing is providing some assistance for the students to see how much they are paying attention,” Zhang said. “Because the data is transferred to the teacher, the students will concentrate more than usual, and we’ve indeed seen some improvements.”

The u-shaped device, which sits across the forehead, was reportedly developed by US-based company BrainCo and local Chinese partner company Zhejiang BrainCo Technology Co Ltd, co-founded by Kong Xiaoxian, a former PhD student at the Harvard centre for brain sciences and a one-time student of the primary school.

A representative from the Chinese partner of BrainCo, also surnamed Zhang, told Beijing News the students wore the devices twice a week for 30 minutes at a time and used them for concentration training courses.

With many children across China using smartwatches, mobile phones and other devices that track location and personal information, parents are becoming increasingly concerned about how that data is used, and who can access it.

A regulation on protecting children’s online information issued by China’s Cyberspace Administration went into effect on 1 October and calls for information to be encrypted, parental consent for collecting, transferring or using that information, and establishing user agreements.

After-hours calls to BrainCo on Friday were not answered and company representatives did not immediately respond to other requests to comment.

Yang Zhangpeng, director of Zhejiang BrainCo Technology Public Relations, told the Guardian: “I’m not sure why the government has barred the use of the bands but it might be partly due to media pressure.”

“Currently this is the only school in China that’s been using them. The products are more widely used in the US but since Kong was once a student of that school, he decided to donate some of these headbands out of gratitude for his alma mater, with no ill intention.”

“The data collected will only be stored at the school’s database, not even the company’s; nor do we share these data with parents; even teachers can only view the average numbers instead of those of specific individuals.”

Additional reporting by Zhong Yunfan