Smartphone app performs better to detect cardiac arrest

A smartphone application using the camera function was able to detect flawed blood flow in a wrist artery for patients undergoing coronary angiography, during a randomized trial, said some recent findings.

The results highlight the potential of smartphone applications to help physicians make decisions instantly, said researchers. "Because of the widespread availability of smartphones, they are being used increasingly as point-of-care diagnostics in clinical settings with minimal or no cost," said Dr. Benjamin Hibbert of the University of Ottawa Heart Institute, Ottawa, Ontario.

Built-in cameras with dedicated software or photodiode sensors using infrared light-emitting diodes have the potential to render smartphones into functional plethysmographs or instruments that measure changes in blood flow, he said. The researchers compared the use of a heart-rate monitoring application (the Instant Heart Rate application version 4.5.0 on an iPhone 4S) with the modified Allen test, which measures blood flow in the radial and ulnar arteries of the wrist, one of which is used to access the heart for coronary angiography.

A total of 438 participants were split into two groups; one group was assessed using the app and the other was assessed using a gold-standard traditional physical examination (known as the Allen test). The smartphone app had a diagnostic accuracy of 94% compared with 84% using the traditional method.

"The current report highlights that a smartphone application can outperform the current standard of diagnostics, said Dr. Hibbert. "However, it is important that they are evaluated in the same rigorous manner by which we assess all therapies and diagnostic tests," said lead author Dr. Pietro Di Santo.

Although this application is not certified at present for use in health care by any regulatory body, the study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient’s bedside in the future, said Dr. Hibbert.

The findings have been published in the Canadian Medical Association Journal (CMAJ).