Understanding Congestive Heart Disease
One out of five people in the world are at risk of developing congestive heart failure. Risk of contracting the disease rises with age. Since there is no cure for it at present, patients must closely monitor their lifestyle changes or medication to prevent irreversible damage to their heart function.
In congestive heart failure, the diseased or overworked heart ventricle is unable to pump out enough of the blood received from the lungs. Pressure builds up first in the heart, then in the veins and capillaries in the lungs. In turn, fluid is pushed back through the capillary walls and into the air sacs of the lungs.
Hence, when air passes through these fluid-filled air sacs, crackles are heard from the lungs. Depending on the intensity, a crackle may sound like salt added to a hot pan, or Velcro being torn apart.
To confirm symptoms of congestive heart failure, such as fluid accumulation in the lungs, patients have to go for a clinical examination. Even so, results from the test are subjective, or expensive and timely given the need for imaging modalities and serum biomarker tests.
Devices for Congestive Heart Disease
Faced with this challenge, a team of researchers from Singapore’s Nanyang Technological University (NTU) and Tan Tock Seng Hospital (TTSH) have developed a smart handheld medical device. NTU’s Associate Professor Ser Wee and TTSH’s Associate Professor David Foo led the team in creating the non-invasive device. Associate Professor Ser is from NTU’s School of Electrical and Electronic Engineering.
Associate Professor Ser clued in on the unique set of diseases’ symptoms to identify characteristic sounds unique to patients with fluid accumulation in the lungs. Next, they developed a proprietary AI algorithm capable of identifying and processing these signals to determine if there is fluid accumulation in the lungs.
The device will enable early intervention for patients with congestive heart failure. Resembling a stethoscope, the portable device is made up of an acoustic sensor connected to a smartphone. A mobile app then picks up breathing sounds and sends them to a server in the cloud. The NTU-developed algorithm stored in the cloud processes the sound signals. The processed results are shown on the mobile app.
Although it is at the prototype stage, the device is able to detect any excess fluid in the lungs in a short span of ten seconds as soon as it is placed on the patient’s chest or back.
During a pilot study, lung sounds from 86 TTSH’s congestive heart failure patients were recorded. When Associate Professor Ser and his team tested the device on patients, they found it was able to yield a 92% accuracy in identifying patients with the condition. This is comparable to present ‘gold standard’ diagnosis methods like X-rays and CT scans.
Associate Professor Foo, Head of Cardiology at TTSH, said, “Patients can monitor their condition at home and use the device whenever they feel slightly breathless at home. It is potentially a game-changer in the management of ambulatory heart failure patients. It can also provide a rapid and accurate acute diagnosis of heart failure in situations of undifferentiated shortness of breath symptoms.”
Associate Professor Ser added, “Currently, such diagnosis can only be conducted through clinical examination, which cannot be made frequently. Our smart medical device can be used by anyone, anywhere and any number of times, which will enable the possibility of early intervention of congestive heart failure.
“The next wave of MedTech (medical technology) start-ups will see the massive proliferation of smart medical devices that rely on artificial intelligence (AI) and sensing technologies, such as the one we invented, and that will enable personalised self-assessment and screening of cardiopulmonary and other diseases, and revolutionise the way healthcare is managed in future.”
In the Pink of Health
The team is running a third round of tests on the device to further validate its sensitivity and specificity. In the process of product refinement, the research team has filed a patent for the invention.
A promising MedTech product, a major pharmaceutical company, a healthcare MNC and a local healthcare company have approached the team to explore the possibility of collaborations already. A MedTech startup from NTU is also looking to commercialise the device.
Before mass producing the product, the team will seek clinical and regulatory validation for the device.
The team’s findings were also presented at the 2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society.