A "potentially revolutionary" device to help women during difficult births has come from an unlikely source - a car mechanic from Argentina, who based the idea on a party trick.

Apart from having five children of his own, Jorge Odon had no connection with the world of obstetrics. He did however have a talent for invention.

"It comes naturally - for instance if I have a problem in my workplace I will go to bed and my head will think it through and I will wake up in the middle of the night with a solution," he says.

But until 2005, all his patents - eight in total - were in the field of mechanics, stabilisation bars, car suspensions and the like.

All this changed after Odon's staff at the garage showed him a YouTube video revealing how to extract a loose cork from inside an empty bottle. It's remarkably simple. You tilt the bottle, stuff a plastic bag down the neck and blow into the opening. The bag balloons inside the bottle, wrapping itself tightly around the cork. Then you just pull it out.

Two men in the toilet, with my daughters' toys, taking them out of a jar, with Vaseline - our colleagues thought we were mad Jorge Odon

Odon immediately challenged a friend, Carlos Modena, to a bet over dinner. He placed a bottle containing a cork on the dinner table, and laid out several objects, including a bread bag. Thoroughly puzzled, Modena insisted the only way of getting the cork out would be to smash the bottle. So Odon showed him his trick, and won the bet.

But that night, as he slept next to his wife, Odon had a lightbulb moment - what if he used the same principle to help women give birth? At 04:00 he tried to wake her up. "Marcela, this cork trick could make labour easier!" he said. His wife mumbled, "That's nice," turned over and went back to sleep.

In the days that followed, Odon kept mulling it over, but found it difficult to get people to listen to him. Most thought the idea was crazy. Eventually he persuaded Modena to introduce him to his family's obstetrician.

Image caption Jorge Odon demonstrates the device on a dummy at Des Moines University

"We went to a hospital and sat - in our suits - in a room full of expectant mothers," Odon says. "My friend was still sceptical, so when we went to see the doctor, at first he sat quite far away from me. But once he saw that the doctor was interested in this idea and quite impressed, he moved his chair closer and started saying 'we' have invented this!"

For many years, almost centuries, there has been no innovation in this area of work Mario Merialdi, WHO

Encouraged, Odon registered a patent and set about building a prototype. He and Modena took his daughter's dolls and some jam jars, and began experimenting in his workshop. "Two men in the toilet, with my daughters' toys, taking them out of a jar, with Vaseline. Our colleagues could see us and obviously they thought we were a little bit mad," he says.

Once he had a working model, Odon approached Dr Javier Schvartzman at the Centre for Medical Education and Clinical Research in Buenos Aires. When Odon got out his bottle and cork, Schvartzman wondered if he was being secretly filmed for a hidden-camera show.

"When he showed me the trick I thought it was crazy - crazy but interesting," he says. But he agreed to work with Odon to develop the device.

The first prototype was a glass uterus, into which two large bags were introduced. When Schvartzman explained that thrusting a bag all the way into the uterus might perforate its lining, Odon adapted the model so that the bag was only applied over the head.

By 2008, the project had come to the attention of the World Health Organization. On a visit to Buenos Aires, its chief co-ordinator for improving maternal and perinatal health, Dr Mario Merialdi, asked for a demonstration. The meeting, planned to last 10 minutes, stretched to two hours.

"I was intrigued, but also sceptical because for many years, almost centuries, there has been no innovation in this area of work," Merialdi says.

Birthing instruments are used in about one in 10 births, usually forceps, or the ventouse - where a suction cap attached to the head helps to pull the baby out. Both have downsides. Forceps may damage vaginal tissues and can fracture the baby's skull, as there is no limit to how much force you can apply. A ventouse delivery is less traumatic for the mother, but may still damage the baby's scalp.

Image caption Bruising from forceps and scabs from ventouse

Forceps were first developed in the 16th Century by the Chamberlen family, Huguenot surgeons who fled to London from France, and kept their invention under wraps. Once their secret got out, other surgeons copied them. "The Victorian era saw some monstrous modifications such as attaching the handles of the forceps to a winch, while the mother was tied down, in order to improve the traction," says Damian Eustace from the Royal College of Obstetricians and Gynaecologists. However, the forceps in use today haven't changed much since the late 1800s - the more complicated they become, the harder they are to use and the more expensive to sterilise.

The earliest known vacuum extractor - the Air Tractor - was produced in 1838 by James Young Simpson in Edinburgh. But it only really became a practical alternative to the forceps in the 1950s with the development of the Malmstrom extractor, named after Swedish professor Tage Malmstrom. "Modifications of his original design are still in use on labour wards today," Eustace says, but new materials (plastics and siliconised rubber) have radically improved the apparatus and, at least in the UK, it is now used more commonly than forceps.

History of birthing instruments Chamberlen forceps (top) date back to the 16th Century

The ventouse (above) has been widely used since the 1950s, when a metal cap was designed in Sweden by Professor Tage Malmstrom

The Odon device imitates the bottle trick. A double layer of plastic is inserted via the birth canal to surround the baby's head. Some air is then pumped into the bag, inflating a plastic chamber that gently grips the head around the chin (there is no obstruction to the baby's breathing because it does not breathe through the nose until birth). Then the baby can be pulled out through the birth canal, without causing damage or bleeding.

In 2008, Odon took his creation to Des Moines University in Iowa for extensive testing in a state-of-the-art birth simulator, with WHO experts observing closely. This was a turning point for Odon.

"I couldn't believe that they would believe in me. It was a special moment," he says.

The experts could see the potential for this cheap and simple device in developing countries, where prolonged or obstructed births are often fatal.

Media playback is unsupported on your device Media caption Animation showing how the Odon device works

Worldwide, about 5.6 million babies are stillborn or die soon after birth every year. Some 260,000 mothers die as well - 99% of all maternal deaths occur in developing countries. Mothers may bleed to death or die from infection, whereas newborns are in danger of suffocating. Where the mother survives, she may suffer serious complications such as fistula, where tearing links the vagina with the rectum or bladder.

Schvartzman says the most important thing is that the Odon device is easy to use - it could potentially be used by a midwife without a doctor present. It also reduces the risk of transmission from mother to baby of infections such as HIV. And, in developed countries, it could help bring down soaring rates of Caesarean births.

"These features combined make it a potentially revolutionary development in obstetrics," says Merialdi.

The next phase was to test the device in real-life situations.

"The first time I saw it used I promised that if it worked, I would shave off my moustache," Odon says. The moustache had to go.

"I am not sure I would be very comfortable letting my wife, the mother of my children, use some device that has never been tested," Odon says. "But all the women who have volunteered for these trials, they do it for the progress of science, which is something truly beautiful."

Mariana Macchiarola, a 35-year-old singing teacher, was one of 30 women who agreed to pioneer the device. Like the others, she had given birth before.

"To give birth to my first son was a good experience, but quite painful," she says. "I was very frightened and they ended up having to help me by giving me an episiotomy (a cut to the perineum). I suffered a little - it's labour, right?"

In the initial trials the bag was inserted using a spatula, but it wasn't easy. So Odon went home to work on the problem. By the fifth birth, he had invented an inserter, "a very ingenious instrument that permits us to introduce the bag in a very easy way," Schvartzman says.

Macchiarola was the first patient to benefit from the inserter, which was finished the night before she gave birth, in an unusually busy hospital ward.

"Jorge was there, as well as several midwives and obstetricians. There were people filming. It was something truly spectacular," she says. "I had no pain whatsoever. It was very quick and I got to enjoy watching the birth of my son. The first time, I hadn't managed to see it, given my desperation! This time around, I could enjoy it. And it wasn't necessary to get an episiotomy."

Image caption Patient No 5 - the inserter was invented the night before baby Leon was born

The inserter evolved still further, with Odon submitting three more patents over the course of 30 trial deliveries. Trials are now continuing on 100 healthy women in Argentina. The next phase of the study will see it tested in problem births in Africa, Asia and Europe.

If the trials go well, Merialdi predicts the device could be in clinical use in two or three years' time. The US company that will manufacture the device, Becton Dickinson and Company, says it will sell it cheaply to developing countries. This is very important to Odon.

"The important thing is that it's affordable so that it can reach everywhere," he says. "More than the economic side of this I have always wanted to save lives, to help people."

Schvartzman puts the success of the project down to two factors: "The genius of Jorge Odon - and the fact that we paid attention.

Delivery is a mechanical process so it's not surprising a mechanic solved this problem Dr Mario Merialdi, WHO BBC Health: Pregnancy calendar

"Maybe another doctor would have said goodbye, but we didn't, and that's what has led to this fantastic device," he says. "Doctors are very structured in their thinking and Jorge is a free mind, he can think of new things."

Merialdi agrees that it took an outsider to think of a new approach.

"Albert Einstein used to say that sometimes imagination is more important than knowledge and this is actually the case, because Jorge didn't have any knowledge of obstetrics," he says.

"It's also true that although delivery is a biological function, it's also a mechanical process and so it's not surprising that a mechanic found a way to solve the problem of protracted or obstructed labour. I doubt an obstetrician like me would have thought of a plastic bag with an air chamber in it."

Odon's life has changed completely since he developed his device, and he has handed over the running of the garage to his son.

"In the beginning I used to work in my mechanic workshop so every time there was a birth I had to change my clothes very quickly and go to the hospital, so it was quite crazy. Now I am just working 24/7 on this, otherwise my health would have deteriorated."

But he still can't quite believe that his dream is about to become reality.

"I woke up one night with this idea, it almost felt magical. What I cannot understand is how I came up with a solution to help babies be born. I'm moved by the potential of this invention and I'm especially grateful to the doctors who first believed in me."

Additional reporting by Marco Silva. Jorge Odon spoke to Outlook on the BBC World Service. Listen again on iPlayer or get the Outlook podcast.

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