Car-maker Honda has unveiled a prototype of a battery-powered unicycle, deigned for the elderly.

The one-wheeled U3-X "personal mobility vehicle" can travel at speeds up to six kilometres (3.7 miles) per hour and was shown off in Tokyo, Japan.

The sit-on design allows a rider to move by leaning their weight in the direction they want to travel

Some of the technology in the vehicle was originally developed as part as Honda's humanoid robot project ASIMO.

For example, it uses the same balance control technology as the bipedal robot, featured in its television adverts.

The 10kg vehicle also uses what the firm claims to be the "world's first omni-directional driving wheel system", which enables it to move in all directions.

The "Hot-Drive" system uses a series of small motor-controlled wheels connected together to form one large wheel.

This main wheel allows a rider to move forward and backward. The smaller wheels allow the device to move from side-to-side. A combination allows the device to move diagonally.

Honda is planning to showcase the U3-X at the Tokyo Motor Show 2009 on October 24, 2009.

However, Honda President Takanobu Ito said the machine was still "a proposal" and the company had no plans for when and if it will go on sale.

With more than 22% of Japans population over retirement age, the country is increasingly turning towards technology to help deal with its rapidly aging society.

Toyota, for example, has previously demonstrated its Winglet to help people move around. The device is similar to the Segway, an upright two-wheeled scooter manufactured in the US.