Image: The Instant Heart Rate monitoring application (Photo courtesy of Azumio).
A smartphone application that assesses ulnar artery patency via photoplethysmography is diagnostically superior to traditional physical examination, according to a new study.
Researchers at the University of Ottawa (Canada), Mount Sinai Health System (MSHS; New York, NY, USA), and other institutions conducted a study in 438 patients in order to compare the use of the Azumio Instant Heart Rate monitoring application on an iPhone 4S to the modified Allen test, which measures blood flow in the radial and ulnar arteries of the wrist in order to evaluate the collateral circulation to the hand, and determine patient eligibility for radial artery access.
Study participants were split into two groups; one group was assessed using the app, and the other was assessed using the Allen test. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries. The primary outcome was diagnostic accuracy of the heart rate monitoring application. The results revealed that the Azumio app had a superior diagnostic accuracy (91.8%) than that of the modified Allen test (81.7%). The study was published on April 3, 2018, in the Canadian Medical Association Journal (CMAJ).
“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 Benjamin Hibbert, MD, of the University of Ottawa Heart Institute. “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.”
“When smartphones and apps begin to be used clinically, it is important that they are evaluated in the same rigorous manner by which we assess all therapies and diagnostic tests,” said lead author Pietro Di Santo, MD, of the University of Ottawa. “When we designed the study, we wanted to hold the technology to the highest scientific standards to make sure the data supporting its use was as robust as possible.”
Color Doppler ultrasonography imaging is the gold standard method for assessing arterial patency and collateral competency, but it is relatively resource-intensive and thus seldom feasible or cost-effective in routine clinical practice.
University of Ottawa
Mount Sinai Health System