Researchers have developed a handheld device that could potentially replace stethoscopes as a tool for detecting certain types of heart disease.

Researchers from the University of Cambridge developed a device that makes it easy for people with or without medical training to record heart sounds accurately. Unlike a stethoscope, the device works well even if it's not placed precisely on the chest: its 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. The researchers are also developing a machine learning algorithm which can detect signs of valve disease automatically. The results are reported in the IEEE Journal of Biomedical and Health Informatics.

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 50% of patients with significant VHD remain undiagnosed, 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 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. However, just 38% of patients who present to their GP with symptoms of valve disease receive an examination with a stethoscope.

"The symptoms of VHD can be easily confused with certain respiratory conditions, which is why so many patients don't receive a stethoscope examination," said Professor Anurag Agarwal from Cambridge's Department of Engineering, who led the research. "However, the accuracy of stethoscope examination for diagnosing heart valve disease is fairly poor, and it requires a GP to conduct the examination."

In addition, a 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 this can only be done in a hospital, and NHS waiting lists are extremely long—between six to nine months at many hospitals.

"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," said Agarwal.

Agarwal and his colleagues have developed a handheld device, about the diameter of a drinks coaster, that could be a solution. Their device can be used by any health professional to record heart sounds and can be used over clothes.

While a regular or electronic stethoscope has a single sensor, the Cambridge-developed 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.

The device contains materials that can transmit vibration so that it can be used over clothes, which is particularly important when conducting community screening programs to protect patient privacy. Between each of the six sensors is a gel that absorbs vibration so the sensors don't interfere with each other.

The researchers 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.

In parallel with the development of the device, the researchers have 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.

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

The researchers say that the device could be a useful tool to triage patients who are 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. Anurag Agarwal is a Fellow of Emmanuel College, Cambridge.