The system sends inaudible sounds from the speaker out into a room and, based on the way the sounds are reflected back to the speaker, it can identify and monitor individual heartbeats. Because the heartbeat is such a tiny motion on the chest surface, the team's system uses machine learning to help the smart speaker locate signals from both regular and irregular heartbeats.
When the researchers tested this system on healthy participants and hospitalized cardiac patients, the smart speaker detected heartbeats that closely matched the beats detected by standard heartbeat monitors. The team published these findings in Communications Biology.
"Regular heartbeats are easy enough to detect even if the signal is small, because you can look for a periodic pattern in the data," said co-senior author Shyam Gollakota, a UW associate professor in the Paul G. Allen School of Computer Science & Engineering. "But irregular heartbeats are really challenging because there is no such pattern. I was not sure that it would be possible to detect them, so I was pleasantly surprised that our algorithms could identify irregular heartbeats during tests with cardiac patients."
While many people are familiar with the concept of a heart rate, doctors are more interested in the assessment of heart rhythm. Heart rate is the average of heartbeats over time, whereas a heart rhythm describes the pattern of heartbeats.
For example, if a person has a heart rate of 60 beats per minute, they could have a regular heart rhythm - one beat every second - or an irregular heart rhythm - beats are randomly scattered across that minute but they still average out to 60 beats per minute.
"Heart rhythm disorders are actually more common than some other well-known heart conditions. Cardiac arrhythmias can cause major morbidities such as strokes, but can be highly unpredictable in occurrence, and thus difficult to diagnose," said co-senior author Dr. Arun Sridhar, assistant professor of cardiology at the UW School of Medicine. "Availability of a low-cost test that can be performed frequently and at the convenience of home can be a game-changer for certain patients in terms of early diagnosis and management."
MEDICA-tradefair.com; Source: University of Washington
