- Canadian researchers have found that an mHealth app is better than a traditional bedside examination for determining blood flow in a patient’s wrist.
In a study published this month in the Canadian Medical Association Journal (CMAJ), doctors at the University of Ottawa Heart Institute have reported that a heart rate monitoring app installed on an iPhone 4S had a diagnostic accuracy rate of 94 percent in measuring blood flow in the radial and ulnar arteries in the wrist of patients undergoing coronary angiography.
When doctors performed a bedside exam, called a modified Allen test, the diagnostic accuracy rate was only 84 percent.
"The current report highlights that a smartphone application can outperform the current standard of care and provide incremental diagnostic yield in clinical practice," one of the researchers, Dr. Benjamin Hibbert, told domain-b.com.
"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," Hibbert said. "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.”
In the study, led by Dr. Pietro Di Santo, the researchers noted that the mHealth app could improve clinical outcomes for coronary angiographies and other procedures, as there are some concerns that the traditional method of analyzing blood flow by a physical exam isn’t reliable.
“Performing the modified Allen test before radial artery access is recommended currently by numerous medical societies — including before transradial cardiac catheterization, acquisition of arterial blood gases and harvesting of the radial artery for coronary artery bypass grafting,” they wrote. “In addition, the reverse modified Allen test is performed commonly to assess for radial artery occlusion after transradial artery catheterization. Although Doppler ultrasonography remains the gold standard, the modified Allen test remains the predominant form of ulnar patency assessment because this test can be performed at point of care. Based on our results, if the modified Allen test is to be used, replacing it with a photoplethysmography-based assessment using a smartphone application has the potential to increase the number of patients eligible for radial artery access by 10 percent over standard clinical care.”
In an accompanying commentary, Dr. Kumanan Wilson, a specialist in general internal medicine at the Ottawa Hospital, said the study proves “there is much to be optimistic about in mHealth.”
“Cell phone technology provides an easily accessible and superior alternative to physical examination to assess radial collateral circulation,” Wilson writes. “The study’s authors should be congratulated for conducting a rigorous evaluation of the application of their technology, because most mHealth applications do not undergo any evaluation. As the authors point out, in addition to its potential health benefits, this technology could have important implications from a resource perspective; given the ubiquity of smartphone technology, the cost of its application would be minimal.”
Both the study and Wilson’s commentary also highlight the challenges to adoption for diagnostic mHealth technology. Wilson notes the study used the iPhone 4S, which has since been surpassed by newer models, requiring more testing to make sure the technology is still effective.
And, he added, there are still many hoops to jump through to verify that mHealth technology is reliable and safe enough for clinical use.
“A previous analysis of US Food and Drug Administration regulatory studies showed that few mHealth technologies receive approval for clinical study,” Wilson said. “Arguably, the use of a smartphone for the purposes described in Di Santo and colleagues’ study meets the standards of a medical device — a health or medical instrument used in the treatment, mitigation, diagnosis or prevention of a disease or abnormal physical condition. However, uncertainty remains over the regulatory standards governing many mHealth applications, and, as previously discussed in CMAJ, it is not clear which mHealth medical devices are low or high risk and, therefore, what the process should be for achieving regulatory approval.”
But both Wilson and those involved in the study say the technology offers an improvement on the current way of doing things – and could make the smartphone the diagnostic device of choice for physicians in the hospital.
“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,” the study concluded.
Added Wilson: “the impact of digital technologies will be both disruptive and transformative. The continued maturation of technologies, such as artificial intelligence, virtual reality and blockchain, will further expand the possibilities for mHealth in both diagnosis and treatment in health care. It is incumbent upon the health care profession to address proactively the many challenges mHealth presents to best maximize its benefits.”