iPhone app measured blood flow better in cardiac assessment

Scientists have used an app on iPhone 4S to assess blood flow in a wrist artery for patients undergoing coronary angiography that performed better than the traditional physical examination.

The smartphone app had a diagnostic accuracy of 94 per cent compared with 84 per cent using the traditional method.

Although this application is not certified at present for use in health care by any regulatory body, "our study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient's bedside," said Dr Benjamin Hibbert from the University of Ottawa Heart Institute, Ottawa.

Researchers used the smartphone's camera function to reach the conclusion, according to a randomised trial published in CMAJ (Canadian Medical Association Journal).

"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 Hibbert.

"For example, built-in cameras with dedicated software or photodiode sensors using infrared light-emitting diodes have the potential to render smartphones into functional plethysmographs [instruments that measure changes in blood flow]," he added.

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 the Allen test.

"The current report highlights that a smartphone application can outperform the current standard of care and provide incremental diagnostic yield in clinical practice," Dr Hibbert wrote.

"However, while smartphones aren't designed as medical devices, it is important that they are evaluated in the same rigorous manner by which we assess all therapies and diagnostic tests," noted lead author Dr Pietro Di Santo.