One evening in March, Daryn Peterson was stretched out on his sofa at home. After a hard day's work, he was totally relaxed and just watching TV. Then, when the weather forecast came on, he sat up suddenly. It was as if lightning had struck his brain; an idea had suddenly flashed into his mind.

"I saw a mother having trouble carrying her baby while trying to hold up an umbrella in the rain," said Peterson. "And all of a sudden, the exact design popped into my head that would make a standard umbrella become hands-free with the addition of only one part -- and my Kataburera (shoulder umbrella) was born."

Peterson's Kataburera was, he says, "inspired by our backbone." It is basically a regular folding umbrella but with an 80-cm-long, 3-cm-wide handle made of bendy plastic with a nonslip cover that can be wrapped round the shoulder to make it hands-free, then unwrapped and straightened out again for normal use. Weighing in at just 220 grams, it's no problem even for the elderly or infirm to use.

Peterson, who practices holistic medicine in Tokyo's Kita Ward, did everything himself. Starting from scratch, he went to hardware stores to find the perfect material, then he researched and contacted a factory in China that could make the umbrellas for his target price. He even studied a bit of Chinese so he could communicate with the factory workers.

"I used 3 million yen of my savings on this," said Peterson with a laugh. "I had no weekends, no time to play. I was seeing patients during the day, and creating my Kataburera during the night."

But before his invention went into production in China, for Peterson -- just like any other product manufacturer -- there was the essential process of market research to go through.

For this, with a few prototypes he made himself, he made his way to the popular Tokyo districts of Shinjuku, Omotesando, Ikebukuro and Omiya, where he got 600 people to "road test" his bendy brolly.

The results were extremely encouraging. "Many people pointed out that the Kataburera was convenient not just for those holding children or lots of bags, but also for gardening, riding a bicycle or mountain climbing," he recalled. "And only a few said it was uncool," he added with a laugh.

It is now three months since his Kataburera went on sale in April, and already Peterson has sold more than 3,000. But now, he has a loftier goal -- to tap into the health-insurance market.

According to Peterson, the Kita Ward Office is planning to assess the suitability of his Kataburera for use by the elderly, the infirm and those using wheelchairs or white sticks. If it is approved, such citizens of Kita Ward will be able to buy one for only 30 percent of the regular 2,440 yen retail price.

"In Tokyo alone, nearly 40 people die every year from accidents like slipping in the rain," said Peterson. "In fact the government recommends that elderly people stay home when it rains to avoid accidents like that. But now the Kataburera will give them new freedom in the rain as they will be able to use both their hands freely."

"I think that the Kataburera will change the umbrella era," said Peterson. "Soon, holding an umbrella with your hands will become old news."