Carefully avoiding the hall mirror you reach for your car keys - and find instead a sturdy-looking, little black box.
You pick up the device, take a deep breath, put it to your lips and blow. If your alcohol level is low enough, a green light comes on and out pop your keys. But you may face instead a brief pause followed by the ominous winking of a red light. Then the box remains stubbornly shut. It has been six hours since you stopped drinking but you are still over the limit and unfit to drive. A momentary feeling of irritation, and a fleeting desire to smash the box and snatch your keys, fades when you realise it is probably too strong for you. Now, where did you put that bus timetable?
The key-safe breathalyser won for its inventor, Rebecca Child, now 18, the title of Young Innovator of the Year. "My dad saw an advert for the John Logie Baird Awards last year," she says. "And I'd already designed the key-safe for entry into the product design engineering course I'm doing at Glasgow University. So I thought I'd send it in.
"I got the idea after reading about doctors going to work and making mistakes because they'd been drinking the night before. I wanted a device that would prevent that, and could hold keys for other equipment, such as industrial machinery, that you don't want people to use when they're under the influence.
"I did some research and found there were several types of breathalyser. But I didn't find anything like the sort of thing I had in mind that would hold your keys for you. So I made a model out of a wee garage door remote-control, which is a handy size to fit in your pocket. And I prepared a set of drawings and wrote down what the device would do, where the idea came from and other possible applications for it.
"After I'd contacted Scottish Innovation, they asked me to go to a workshop on designing, giving presentations and setting up a business. I wasn't sure what to expect, so I took my mum. But it was great. There was nobody near my own age - it seemed to be all men and women who had their own businesses or invented as a hobby. But they gave me a lot of help about things like patenting, how to get further with the design, who to go to for money and so on. I learned a lot.
"Later on they told me I'd got through to the Ayrshire finals, and then I made it to the national finals. Eventually I won the Young Innovator of the Year award, which was presented by John Logie Baird's son Malcolm. There were loads of people there and it got me a lot of recognition and contacts. It was great."
For application forms and further information on the John Logie Baird Awards, contact Scottish Innovation, 8 Park Quadrant, Glasgow G3 6BS, tel: 0141 332 3535, fax: 0141 332 2525Chris Smith, the Culture Secretary, recently announced the launch of the National Endowment for Science, Technology and the Arts (NESTA), a fund to support innovators which has been set up with pound;200 million of lottery money. More information at http:www.nesta.org.uk