New device could replace stethoscopes for heart disease screenings

By Stephen Beech

A new handheld device could replacing traditional stethoscopes for heart disease screening, say scientists.

University of Cambridge researchers have developed an instrument for detecting certain types of heart disease.

They say the device makes it "easy" for people with or without medical training to record heart sounds accurately.

Unlike a stethoscope, the team explained that the device works well - even if it’s not placed precisely on the chest: as it's larger, flexible sensing area helps capture clearer heart sounds than traditional stethoscopes.

The device can also be used over clothing, making it more comfortable for patients – especially women – during routine check-ups or community heart health screening programs.

The heart sound recordings can be saved on the device - which can then be used to detect signs of heart valve disease, according to a study published in the IEEE Journal of Biomedical and Health Informatics.

The Cambridge team is also developing a machine-learning algorithm that can detect signs of valve disease automatically.

Heart valve disease - valvular heart disease or VHD - has been called the "next cardiac epidemic" - with a prognosis worse than many forms of cancer.

Up to half of patients with significant VHD remain undiagnosed, say scientists, and many patients only see their doctor when the disease has advanced and they are experiencing significant complications.

In the UK, the NHS and NICE have identified early detection of heart valve disease as a "key" goal, both to improve the quality of life for patients and to decrease costs.

An examination with a stethoscope, or auscultation, is the way that most diagnoses of heart valve disease are made.

But just 38% of patients who present to their GP with symptoms of valve disease receive an examination with a stethoscope.

Research leader Professor Anurag Agarwal, of Cambridge’s Department of Engineering, said: “The symptoms of VHD can be easily confused with certain respiratory conditions, which is why so many patients don’t receive a stethoscope examination.

“However, the accuracy of stethoscope examination for diagnosing heart valve disease is fairly poor, and it requires a GP to conduct the examination.”

A traditional stethoscope examination requires patients to partially undress, which is both time-consuming in short GP appointments and can be uncomfortable for patients, particularly for female patients in routine screening programs.

The "gold standard" for diagnosing heart valve disease is an echocardiogram, but that can only be done in a hospital and NHS waiting lists are between six to nine months at many hospitals.

Agarwal said: “To help get waiting lists down, and to make sure we’re diagnosing heart valve disease early enough that simple interventions can improve quality of life, we wanted to develop an alternative to a stethoscope that is easy to use as a screening tool."

Agarwal and his colleagues have developed a handheld device, about the diameter of a drinks coaster, that could be a solution.

The device can be used by any health professional to accurately record heart sounds, and can be used over clothes.

While a regular or electronic stethoscope has a single sensor, the new device has six, meaning it is easier for the doctor or nurse – or even someone without any medical training – to get an accurate reading, simply because the surface area is so much bigger.

Between each of the six sensors is a gel that absorbs vibration, so the sensors don’t interfere with each other.

The research team tested the device on healthy participants with different body shapes and sizes and recorded their heart sounds.

Their next steps will be to test the device in a clinical setting on a variety of patients, against results from an echocardiogram.

The team has also developed a machine learning algorithm that can use the recorded heart sounds to detect signs of valve disease automatically.

Early tests of the algorithm suggest that it outperforms GPs in detecting heart valve disease.

Agarwal added: “If successful, this device could become an affordable and scalable solution for heart health screening, especially in areas with limited medical resources."

The researchers say that the device could be a "useful" tool to triage patients waiting for an echocardiogram so that those with signs of valve disease can be seen in a hospital sooner.

A patent has been filed on the device by Cambridge Enterprise, the University’s commercialization arm.