At first glance, it looks just like a regular iPhone case. The only detail that seems unusual about the sleek black phone cover is the two small silver pads on the back.

However, this cover is actually a brand-new piece of medical technology: it's a portable heart monitor that uses an iPhone app to record patients' heart rhythms. And Dr. Robert Roeser of Integrity Medicine in Newton will be taking this technology with him when he goes on a medical mission trip this week to the Dominican Republic.

"I am thrilled," he said. "This year, we'll have an EKG that's simple and I can put in my pocket. ... We'll be able to tell them what's going on with their heart rhythm and why."

Roeser will be leaving Saturday for an eight-day trip to the Monte Plata area of the Dominican Republic. He said it was a previous mission trip that inspired him to seek out the iPhone heart monitor, which is manufactured by a company called AliveCor.

On a previous trip, Roeser examined a patient who was experiencing fainting spells. He took her pulse and found it was 120, above the normal* resting heart rate of 60 to 100 beats a minute (*according to Mayo Clinic). Her steady, fast heartbeat was caused by atrial flutter, which meant the patient's heart was pumping too quickly and without enough volume. He suspected the fainting spells were being caused by the patient's lack of blood flow to the brain.

However, Roeser did not have an electrocardiogram (EKG) machine and wasn't able to study her heart rhythm more closely. As he was flying back home, he considered purchasing a portable EKG machine but wasn't sure how easily he could get it through customs. He said the machines can be cumbersome to carry around and to use, since electrodes must be attached to the patient's chest.

When he heard about the AliveCor monitor, he knew he'd found his solution. The monitor consists of an app and a $200 case for iPhones. The patient holds the iPhone and places their fingers on the two small pads on the iPhone case, and the app charts their heart rhythm. The report can be stored on the iPhone or printed out on a piece of paper.

Roeser said the AliveCor device is cheaper than traditional EKG machines, and it's easy to use and sterilize. The device recently was cleared by the FDA and can only be purchased by medical professionals, though Roeser hopes it will be made available to patients at some point.

Roeser is excited to try the device in the mission field and to help provide medical care for those who might not have easy access to treatment.

The first trip to the Dominican Republic can be a "culture shock," he said. The doctors there don't have the luxury of the same type of training as American doctors, and they don't have as much medical equipment. Resources, such as running water, also can be scare.

"They just (make) do with what they have," he said.

No records are kept at hospitals or doctor's offices, so patients must keep their own records. Those who go on the medical mission trip have to set up their own pharmacy and see an average of 110 patients a day.

However, Roeser said the trip is a rewarding — and life-changing — experience.

"I felt like I was doing the same thing I do here," he said. "That was cool."