In sleep medicine, there is a push to move the diagnosis of sleep apnea from the sleep lab to the patient's home. Home sleep studies are done routinely in certain regions of the US - the northeast and west coast, specifically.
Smartphones can do many things these days. These researchers from Japan developed an app for an Android phone that can monitor snoring and even obstructive sleep apnea. The app did this by measuring sound from the patient. Snoring was measured in a similar way that it is done in a sleep lab. But sleep apnea was measured in a novel way - by counting the number of "dips" in sound during recording. The app was tested alongside a standard in-lab sleep study and found to be relatively accurate.
The authors point out that the study has limitations...the first being that the subjects who tested the app were suspected of having sleep apnea. So more research is needed to see if this app would work in the general population as a screening tool. Also, how would the smartphone react if the patient and their bedpartner were snoring? Perhaps the bedpartner could sleep in a separate room for a night to allow the app to evaluate only the patient. The last limitation was that the correlation between sleep apnea severity detected by the app and the in-lab sleep study was not as good when the patient has mild to moderate sleep apnea. It was more accurate for severe sleep apnea.
The authors propose that an app like this could be used less for diagnosis, and more for monitoring changes in snoring as patients change their sleeping position or lose weight. In a commentary after the original article, it was suggested that the app could be used in combination with the phone's accelerometer to alert a patient that they are on their back and snoring. The patient would then roll on their sides again. I can envision an app like this combined with a wire that measures oxygen levels and pulse rate to make a diagnosis at home. This could be an even cheaper home study than what is available now.