A cost-effective next-generation wearable heart and cardiovascular function monitor which uses AI to diagnose heart rhythm and respiratory problems in real time has been developed by a Cambridge spinoff company, Cambridge Heartwear. The company's device, called Heartsense, includes a multiple lead ECG, oxygen sensing, temperature, and tracking device which can be comfortably worn by patients for early screening. Sensors are enclosed in a robust waterproof casing, and the data produced is far more sensitive than that from current single lead wearable devices, as the development team has used their knowledge of clinical anatomy and electrophysiology to place leads for maximal signal output.
This data is wirelessly streamed in real time to the cloud where adaptive AI algorithms are able to identify clinically relevant irregular and dangerous rhythms just as a physician would. The device incorporates multiple independent sensors, in order to produce more specific and sensitive data than current heart monitors can provide. The research challenge was to produce algorithms that can learn from a limited amount of supervision from the cardiologist. To encourage the adoption by clinicians the team ensured that the output of the AI algorithms also included the information commonly used by a cardiologist. This was not necessary for the final diagnosis but made the system a little more understandable and explainable than typical Deep Learning systems, which are still thought of as black boxes.
NHS figures suggest atrial fibrillation (AF), the most common heart rhythm disturbance encountered by doctors, affects in excess of one million people across the UK. According to national and international data, more than 80% of people who either die or are left with severe neurological deficits following a stroke (lat. Apoplexia) had an irregular heartbeat as the underlying cause. However, irregular heartbeat is often diagnosed only after a person has had a stroke.
Heart rhythms are currently measured by an electrocardiogram (ECG). To use an ECG as someone is going about their daily business, rather than in a GP surgery, a device called a Holter monitor is used. This requires fixing 12 leads to the patient's chest and carrying the cumbersome device around for 24 hours. It can take as long as four to six weeks from the time when a patient is referred by their GP to when the data from the Holter monitor is analysed and an irregular heartbeat is detected or not. Additionally, a Holter monitor costs as much as £2000.
The team began collaborating with Cipolla, a world leader in computer vision and real-world applications, and students from the Department of Engineering. The collaboration led to the founding of Cambridge Heartwear in 2017 and the development of the unique device and some powerful algorithms that can automatically interpret ECG data, which have an accuracy level in excess of 95%. In 2017, the company secured funding to build and test 100 prototypes of the new heart monitor and to extend its AI capability. The Royal College of Art was also helped in the ergonomic design of the device. Heartsense will cost substantially less than a Holter monitor. Clinical trials in Lancashire, UK have begun with patients enrolled from the primary care setting.