It's been more than three years since Nintendo first revealed it was developing a "Quality of Life" product, but the company has yet to formally announce the proposed device. The last time we'd heard about it was over a year ago, in February 2016, when Nintendo president Tatsumi Kimishima revealed that it would not be ready for some time. However, according to its annual report for the fiscal year 2017, it appears that Nintendo's mysterious QOL system is still very much in development.

In the section regarding its research and development activities, Nintendo reveals that one of its current initiatives is a "new product that improves people's QOL (Quality of Life) in enjoyable ways." The excerpt does not give much more insight into the product or offer any more details about how it will function, but from the description, it appears to be the same sleep sensor the company has been discussing for the past several years. "Our aim is to enable consumers to make daily efforts to improve their QOL in a fun manner by making sleep and fatigue status visible and offering various services based on this information," the report reads.

Nintendo's first QOL product was to be a sensor that could measure a person's sleep and fatigue levels without the need to be worn. According to the company's late president, Satoru Iwata, the product would be placed at a user's bedside and would automatically measure data about the person's sleep quality. "Inside the QOL Sensor is a non-contact radio frequency sensor, which measures such things as the movements of your body, breathing and heartbeat, all without physically touching your body," Iwata explained.

Since then, however, Nintendo has shared few details on the product. Last year, president Kimishima briefly discussed the device at an investor's briefing, and from the sound of things, it appeared it had a long way to go before it was ready for release. "We do not feel that we are currently at a stage where we can commercialize a product that deals with sleep and fatigue," he said. "So we are not planning to launch any products in this area in the fiscal year ending in March 2016. However, we do believe there is potential in the QOL sector, so we will continue to consider further development in this area."

Nintendo's mysterious QOL product isn't the first time the company has experimented with health and wellness; the exercise game Wii Fit was one of Wii's most successful titles, and Nintendo had even announced a Vitality Sensor peripheral for the console, though that device ultimately never materialized.

More recently, the company has been branching out into other avenues of entertainment, such as partnering with Universal Studio Japan to develop a Nintendo theme park. Nintendo designer Shigeru Miyamoto has also recently expressed interest in creating more video tie-ins for the company's franchises.