If you think stroke and heart attack are mainly problems in wealthy countries, think again.

Middle-income and low-income nations account for about eighty percent of the world’s cardiovascular disease.

Addressing the situation isn’t easy. One reason is, medical equipment may be scarce in poor communities.

Take the basic blood pressure monitor, so common in the U-S that it’s found in supermarkets.

In many places, you can’t even find these monitors in clinics.

So the World Health Organization invited several manufacturers to design a low-cost, solar-powered blood pressure monitor.

It had to be accurate, durable and automated, with a digital readout.

Three companies took up the challenge.

The monitors they designed were first evaluated in a laboratory. Only one was accurate enough for clinical use.

That monitor was then field-tested. The results were published in the journal Hypertension.

The device was provided to health care centers in the Central African nations of Uganda and Zambia.

Almost six-hundred patients volunteered to help with the study.

Each patient had blood pressure readings taken with the solar-powered monitor, and a standard monitor.

The solar-powered model was very accurate for systolic blood pressure, when blood flow is strongest.

It didn’t perform as well on diastolic blood pressure, when blood flow is weakest.

Nevertheless, the health care workers involved gave the solar-powered monitor glowing reviews.

The manufacturer now sells the device.

Perhaps this example will prompt other companies to develop similar products.

After all, it’s a big world out there.

And if businesses can sell affordable medical equipment where it’s needed most, that sounds like a worldwide win-win situation.