Celebrities and professional athletes are among the few Americans with doctors and other health care workers at their beck and call. The rest of us typically are left to our own devices perhaps more often than is healthy: common ailments can go undiagnosed, chronic conditions can run amok and serious illnesses can be mistaken for common colds. But “our own devices” has gained new meaning in recent years. Medical researchers are tapping into sensors in the smartphones we carry with us just about everywhere. A forthcoming wave of apps will help diagnose conditions, spot trouble from afar, and provide a window into our day-to-day condition and health stats so we can get care when we need it most.



WHAT IT DOES: Determines the cause of a cough

HOW IT WORKS: Because respiratory diseases, such as pneumonia, alter the structure of the respiratory tract, each one creates a unique sound signature in a patient's cough. Based on four to five coughs, signal-processing algorithms in this app can detect those patterns, identifying both the type and severity of an ailment.

STATUS: A proof-of-concept trial of 91 patients in 2013 diagnosed pneumonia and asthma with 90 percent accuracy. A second, larger trial is under way; the additional data should allow refinement of the app for bronchitis, bronchiolitis and upper respiratory tract conditions. A version could be ready for release to doctors next year.



WHAT IT DOES: Predicts bipolar episodes before they occur

HOW IT WORKS: This always-on app records a patient's voice during phone calls, listening for changes in speech patterns, such as speed, that might indicate the onset of a depressive or manic episode. Doctors or caregivers will receive alerts when intervention is needed.

STATUS: A pilot study completed last year correctly identified episodic changes in six patients with type 1 bipolar disorder, which is characterized by severe mood swings. Now researchers are working with a larger group (at least 40 subjects) to further refine the technology, in hopes of producing a beta version of the app by the spring of 2016.



WHAT IT DOES: Diagnoses sleep apnea, a condition in which breathing repeatedly stops and starts during sleep

HOW IT WORKS: Inaudible sonar sound waves from the phone's speaker bounce off a patient's body and back to the phone. Variations in breathing alter the signal, allowing algorithms in the app to determine whether or not apnea is present.

STATUS: An initial laboratory trial has shown ApneaApp to be just as effective as hooking up patients to tracking instruments in a sleep clinic, the most common way to screen for apnea. It correctly classified 32 out of 37 patients (missing only cases that doctors usually would consider borderline). Next, the team will design a trial to test the app in patients' homes.