[Image from Caltech]
Ultrasound scans take 45 minutes using the machine. Using the Caltech-developed app, the procedure is cut down to a minute or two.
Huntington Medical Research Institute engineers created a technique that could interpret the left ventricular ejection fraction (LEF) of the heart by measuring the displacement of the skin caused by the carotid artery on the new as blood pumps through. LVEF is an indicator of how much blood is pumped from the heart with each heartbeat. Normal hearts have an LVEF range of 50 to 70%. Weaker hearts tend to have lower LVEF values.
“In a surprisingly short period of time, we were able to move from invention to the collection of validating clinical data,” Mory Gharib, senior author of the paper, said in a press release.
To test the smartphone app, the research team performed a study with 72 participants who were between the ages of 20 and 92. The clinical trials took place at an outpatient MRI facility. Usually, MRIs are the best method to measure LVEF, but it is rarely used because of its high cost. LVEF is most commonly measured using an ultrasound machine during an echocardiography, but needs a trained technician to operate as well as 45 minutes of spare time.
The researchers measured LVEF by holding s smartphone’s camera to the volunteers’ necks for a couple of minutes. The volunteers then had an MRI. The data from both methods was compared and showed that the smartphone measurements had an error of ±9.9& when compared to the MRI. The error for echocardiography had an error of ±10.2%.
“What is exciting about this study is that it shows our technique is as accurate as echocardiography at estimating LVEF when both are compared to the gold standard of cardiac MRI. This has the potential to revolutionize how doctors and patients can screen for and monitor heart disease both in the U.S. and the developing world,” Gharib said.
The walls of the arteries are almost completely elastic which helps the app work. The expanding and contracting of the arteries helps the Caltech-developed smartphone app measure the movements as a waveform that can encode information about the heart.
Massachusetts Institute of Technology researchers also recently developed their own smartphone app that could accurately detect heart arrhythmia by evaluating the amount of light being reflected off of a person’s skin.
Gharib and the researchers are currently working on determining what other measurements an be determined from the data that coms with the smartphone app measurements. The team hopes that the technique could diagnose heart valve diseases in the future.
The study was published in the journal Critical Care Medicine and was funded in part by the Rothenburg Innovation Initiative.
