At around 11 a.m. last December 30, from his office in Oklahoma City, an inventor named David Albert uploaded a webcam video in which he demonstrated how to obtain an electrocardiogram with an iPhone.

Opening his shirt and white lab coat, he placed the phone against his chest. “Now you will see a very clean ECG,” Albert explained, as a heart rhythm pulsed across the screen. “I am detecting and storing, wirelessly transmitting, and storing locally in real time. It’s being analyzed, beats are being identified.”

By noon, the video had 10,000 views. Three days later, it had 100,000. Bloggers and online commenters were insisting the iPhone ECG was a fraud. That was enough to impress Albert’s 12-year-old son: “Dad, you’ve made it. You have YouTube haters!”

The story of the iPhone ECG may also be remembered as an early demonstration of how mobile technology made medicine faster and cheaper. U.S. industry delivers constant advances in high-tech medicine, including new drugs and million-dollar medical scanners. But it does so at a staggering cost. After posting the video, Albert, who is 56, was flooded with thousands of inquiries from first responders and doctors all over the world, as well as from executives at big medical-device firms. “It’s very clear the established companies view this as a threat,” he says.

A serial inventor with 33 issued patents, Albert says that for much of his career, including his years as a top cardiology scientist for General Electric, he was part of the problem. “The job was to create 10 percent improvements in performance for 100 percent price increases,” he says. “For 25 years, I designed ever more expensive technology.”

The ECG reader being developed by Albert’s company, AliveCor, will cost around $100. While it’s not as accurate as a hospital-grade 12-lead ECG, the kind that uses many electrodes pasted to the chest, arms, and legs, Albert calls his phone ECG “almost as good and disruptively less expensive.”

ECGs are used to diagnose irregular heartbeats, or arrhythmias, a common type of medical problem that can also be the result of a heart attack. AliveCor’s monitor is built into a case that slips onto an iPhone. It has two electrodes that pick up voltage changes on the skin—the ECG signal—produced by the contraction of the heart. A low-power wireless transmitter sends the signal to the phone. Power comes from a lithium watch battery that Albert claims will last for 180 hours of continuous use.

“It’s quite a nifty device,” says Eric Topol, a cardiologist and chief academic officer at Scripps Health in San Diego who has been testing it. “Instead of doing a cardiogram, I just have them put their fingers on my phone. It’s really frugal and is a cost savings.”

The phone ECG, which AliveCor manufactures in China, is being studied in clinical trials in Oklahoma and at the University of Southern California and will need approval from the U.S. Food and Drug Administration before being sold in the United States. Albert says it will go on sale in Europe this fall.

At first, AliveCor planned to sell its device to doctors in poor countries. But after meeting with Apple executives about carrying his invention in their stores (discussions are ongoing), Albert believes he could have a consumer hit on his hands, or what he calls a “personal ECG acquisition device you could buy at Walmart.”

Topol says five to six million Americans suffer from the most common arrhythmia, atrial fibrillation. “It’s on my phone, but I’d like to get it on the patients’ phones, so they can send me their rhythm,” he says. “I could instantly tell them whether to go to the emergency room.”

Because so many people have smart phones—some 500,000 Android phones are activated daily worldwide—mobile technology may also upend the economics of some medical devices. Albert knows the low-priced iPhone ECG won’t generate the billion-dollar revenues big companies get from selling medical scanners, but he believes he “can make a little money from an awful lot of people and do really well.”

This August, AliveCor raised $3 million in financing with venture capital firms Burrill & Company, Qualcomm Ventures, and Oklahoma Life Sciences Fund. Following the investment, the company is valued at between $5 million and $10 million.