Masimo Corp. received a $4.95 million grant from Bill & Melinda Gates Foundation in advance of World Pneumonia Day.

The Irvine-based device maker is in the process of developing a low-cost pulse oximeter for pneumonia screening to be used in developing countries around the world.

The device will measure oxygen saturation and respiration rate, two key parameters in identifying potential pneumonia.

Masimo is among the largest publicly traded companies based in Orange County, with a market cap of about $3 billion and more than $600 million in annual sales.

Masimo is led by Chief Executive Joe Kiani.