Ongoing nausea, vomiting and stomach pain can be difficult for doctors to fathom. Once the obvious causes like a gut infection or food poisoning have been ruled out, many patients find themselves on what gastrointestinal surgeon Greg O’Grady calls “a diagnostic treadmill”. The process can take years, involving multiple tests and scans and over-exposure to radiation. Some people never pin down exactly what is going on.
“Unexplained gastrointestinal symptoms are common,” explains O’Grady, a professor at the University of Auckland. “About one in 10 people experience symptoms like indigestion, nausea, pain after eating, bloating. But the clinical tools to diagnose these disorders are poor and have lagged behind other fields of medicine, like cardiology.”
Clearly, what was needed was a non-invasive and accurate way to diagnose patients more quickly. To develop such a solution, O’Grady and a team of Auckland researchers joined forces with a US expert in wearable technologies, Armen Gharibans. The result, a medical device called Gastric Alimetry, is now in use in 37 hospitals and clinics in six different countries.
The innovative system performs a procedure known as body surface gastric mapping. Painless and a relatively speedy procedure, it involves placing a sticky patch of sensors and a recording device onto the skin above the stomach. Over a period of five hours, patients consume a meal to stimulate their digestive system and regularly log symptoms using an app.
The Gastric Alimetry device works on a similar principle to a heart ECG (electrocardiogram), picking up on the electrical pulses that stimulate the muscle contractions that move food through the digestive tract.
“It’s much harder with the stomach because the electrical activity is a hundred times weaker than cardiac electricity, so you need to have very clever technology that can pull out the weak signal, remove other noise from it and distil the important information,” says O’Grady.
A team of medics and engineers has collaborated on the project, with support from the university, the Health Research Council, Callaghan Innovation and venture capital funds.
Moving medical technology from the laboratory to clinical use is a costly and time-consuming process. With patient safety at stake, there is a lot of regulatory scrutiny and high-quality evidence is demanded. Gastric Alimetry now has FDA approval and is approved for use in New Zealand, where currently it is being rolled out to hospitals in the main centres.
The test, which can be performed by any trained nurse or technician, is already helping doctors make better sense of their patients’ symptoms.
“Some do have a serious degenerative stomach disorder that is very hard to treat but fortunately they are the minority,” says O’Grady. “With many patients, the stomach has become hypersensitive, possibly as a result of an infection, and we can treat that with neuromodulation drugs. Others we can reassure that their stomach is fine and move them onto to dietary and psychological support, helping them avoid invasive interventions, which can sometimes do more harm than good.”
As CEO of Alimetry, O’Grady heads a large team. The company now has a commercial base in the US and is raising funds for a wider release there. Meanwhile, clinical trials are ongoing.
“We’re adding to our evidence because we have to show that the device is useful for diagnosis and is making a difference to the patient’s health and their quality of life,” says O’Grady.
He and his team are focused on modifying the system so it is more suited to younger children – currently it is suitable for those over 12 – as they often suffer from unexplained stomach problems.
AI projects are also under way to expand what the system can do. And a wearable take-home version of the device is being explored.
Ultimately, the test has the potential to help diagnose more than solely gastro-duodenal disorders.
“We’re very interested in irritable bowel syndrome, constipation, incontinence; it’s the obvious progression,” says O’Grady. “That’s what we’re evaluating at the moment, to see whether we can provide helpful diagnostic support for those patients.”
