Patients battling severe heartburn could find relief from a small silicone ball implanted in the stomach.

The device, which is a bit smaller than a table-tennis ball, can radically reduce the pain in the chest caused when corrosive stomach acid that breaks down food leaks back up towards the throat.

While heartburn – known as acid reflux or, in severe cases, gastro-oesophageal reflux disease – is common, and can be triggered by eating certain foods, the damage it causes to the oesophagus, which connects the mouth with the stomach, can cause serious complications, including cancer.

The new device, called RefluxStop, tackles the problem by simply exerting gentle pressure on the faulty valve at the top of the stomach to stop acid from escaping.

One of the first Britons to benefit has told how the £12,000 operation ended his two-decade battle with acid reflux. Since undergoing surgery in September, research scientist Dr Andrew Gilfillan's symptoms have gradually improved and now he is able to eat foods he had to avoid for years.

Ever wondered how much of your brain you actually need? The answer may be: not much.

In 2007, Billy McNabb, a 44-year-old French civil servant, visited his doctor complaining of weakness in his left leg.

Scans revealed his skull was filled with fluid – a condition known as hydrocephalus – which left just a thin layer of brain around the outside.

The condition can cause learning disabilities, as well as speech and memory problems, yet Billy had lived a normal life, got married and had two children. Tests showed he had an IQ of 75.

Doctors later drained the fluid, although his brain remained tiny.

'I recently had a curry, which I hadn't been able to eat for as long as I can remember,' says Dr Gilfillan, 57, from Lincoln. 'I also used to have to sleep propped up in bed, as lying flat made the reflux worse, and that was giving me a terrible bad back. Now I don't have to.'

The procedure is available privately at the Spire Manchester Hospital. However, Paul Goldsmith, an NHS upper gastrointestinal surgeon who has specialised in the implant technique, hopes it will soon be rolled out more widely. 'This op is suitable for all patients with reflux disease,' he says.

Although many people experience heartburn from time to time, up to one in five adults suffers painful episodes at least once a week – they are considered to have gastro-oesophageal reflux disease.

Regular heartburn is typically due to a weakness or fault in the lower oesophageal sphincter – a valve at the top of the stomach that allows food to pass through. If it doesn't close properly, stomach acid can flow backwards into the oesophagus, causing pain.

Over time, this can even increase the risk of oesophageal cancer.

The condition is more common in people who are over 40 and obese, as excess weight can put pressure on the stomach and push acid upwards. Smoking, alcohol, spicy foods and citrus can also trigger symptoms. Most people will find that losing weight, avoiding certain foods and taking anti-reflux medicines such as Gaviscon eases the problem, but these do not work in up to 40 per cent of sufferers.

For these patients, an operation is available called fundoplication, in which part of the stomach is stitched round the oesophagus to tighten the sphincter.

Unfortunately, some have problems swallowing afterwards, making matters worse.

The RefluxStop implant works in a different way. The silicone ball is inserted into the stomach and the gentle pressure it puts on the lower oesophageal sphincter helps keep it closed, stopping acid from leaking. However, it doesn't exert enough pressure to hinder swallowing.

Mr Goldsmith says: 'A significant number of reflux patient suffer poor oesophageal motility – problems with the muscles that control the way food passes down the oesophagus into the stomach. This is caused by long-term poorly controlled reflux and the damage stomach acid causes to the oesophagus.

Noses are able to detect and discriminate between a huge range of odours.

They are lined with cells called olfactory receptors, and when the molecules that create an odour bind to one of these receptors, a nerve impulse is triggered which is sent to the brain. There the scent is identified and processed for future recall.

One study, published in the journal Chemical Senses, found that participants in an experiment were able to identify more than 1,000 odours, while other research has put that figure in the tens of thousands.

'Some patients say they have difficulty swallowing – food that 'sticks' or doesn't go down – but others might have no symptoms at all, and it's only when we test that we discover the motility problem.

'These patients typically say their reflux symptoms aren't being controlled by lifestyle or medication, but they might be also unsuitable for fundoplication.

'RefluxStop allows us to maintain the natural anatomy of the oesophagus, treating acid reflux without affecting the food passageway.'

Dr Gilfillan, a married father-of-one, says he had tried to manage his reflux by not eating after 7pm, having smaller, regular meals throughout the day, avoiding his trigger foods and taking over-the-counter medication.

But he adds: 'About four years ago the condition started getting worse. I'd wake up at night coughing due to the acid and partially digested food moving back up into my throat, so I had to sleep propped up. It was horrible.'

When he read about RefluxStop in a newspaper, he decided to try it.

'I dipped into my savings – and I'm glad I did,' he says. 'It's early days, and I'm still getting a bit of reflux, but the night-time symptoms that were not pleasant at all are much better now.'