A pilot study by researchers in the Netherlands has shown the potential of voices recorded on smartphone to detect an impending serious flare up of COPD (chronic obstructive pulmonary disease). COPD is an inclusive term for diseases such as emphysema and chronic bronchitis and is the third leading cause of death worldwide.
Flare ups of COPD, called exacerbations, are characterized by symptoms such as coughing or difficulty breathing. During an exacerbation, the risk of a patient dying increases dramatically and hospitalization is often required. But if patients can receive treatment in the very early stages of an exacerbation, the risks to the patient are significantly lowered.
“After an exacerbation, patients report a lower quality of life, their lung function can decline, and patients are at an increased and prolonged risk for cardiovascular events such as heart attack and stroke,” said Loes van Bemmel, a researcher in the department of respiratory medicine at Maastricht University Medical Center in the Netherlands who presented the findings at the European Respiratory Society (ERS) Congress in Vienna.
“It’s vital to detect exacerbations as early as possible so appropriate treatment can be given. Unfortunately, it has proved difficult to detect exacerbations at their onset, since symptoms usually start when patients are at home,” van Bemmel added.
The research was spurred by patients and families of people with COPD reporting that they have noticed voice changes before and during exacerbations. The pilot study, therefore, sought to see if recording patients’ voices while they were home could provide detectable changes to predict early signs of exacerbations.
For their study, the researchers enrolled 28 people with COPD who were asked to record their voices every day for 12 days on a smartphone app. The participants recorded themselves say “aah” for as long as they could in one breath, then either read a short passage of a story or answered a question.
The patients also completed daily questionnaires to measure their COPD symptoms. During the study, there were 16 instances of exacerbations among the study group.
After the 12-day period, the investigators analyzed the recordings to see if there were specific voice changes that coincided with the patients’ flare ups. They found that patients’ voices showed a higher pitch in advance of an exacerbation and that there was more “jitter” in their voices when an exacerbation was beginning.
“There were clear differences between patients’ recordings on a normal day and on the first day of an exacerbation. This confirmed our hypothesis that speech changes significantly, even at the very beginning of an exacerbation,” van Bemmel said.
Buoyed by their results, the team now plans to partner with researchers at Radboud University Medical Center in the Netherlands to create a mobile app for people living with COPD. Called the SPEAK app, it will be used to help detect exacerbations from speech as well as provide support for treating COPD symptoms at home. The team is also looking for ways to collect, store and analyze speech data from patients while also protecting their privacy rights.
These findings will need to be validated in a larger study, but the Maastricht University researchers believe their work could have broader implications.
“While every disease is different, speech analysis could potentially help in other respiratory diseases as well. We suspect there are speech biomarkers for many respiratory diseases,” van Bemmel concluded.
