Doppel is a new breed of wearable device that delivers tactile beats to the wrist of the wearer in order to change the person's mood. It is said that the device can adjust the body's natural rhythm, depending on whether the owner wants to feel more alert or to feel more relaxed.

The effect of the wearable device is likened to the effect of music to a person - upbeat music awakens the body while downbeat music helps relax the body.

The device is synchronized to a smartphone app that initially measures the resting heart rate of the wearer. This is the only data needed by the device to function and perform its mood-changing capacity.

"You take your resting heart rate through your phone, and then that's the bio-data we need to set the levels that you need to either get calm or to get going. It's not a lot of data, but we're using it very smartly, and that's the approach we take," said co-developer Jack Hooper, according to Reuters.

Using the device, if you want to increase your pulse rate to make yourself more alert, you only have to press the face of the device until it reaches a beat that makes you feel the most comfortably alert. If you want to relax, you can stroke the bezel - the grooved ring holding a watch face cover - to decrease the pace into a beat that is most soothing and relaxing for you.

Developers say they have successfully tested the device on more than 100 people, and had its effects independently verified, The Malay Mail Online reports.