Coronavirus has the greatest effect on the human lungs. This is why lungs of patients with COVID- 19 require constant medical monitoring. One of the tools for the lungs condition monitoring is based on the wireless pulse oximeters connected to smartphones. There is an attempt to analyze the types of pulse oximeters, their technical characteristics, principles of operation and basic requirements for these measuring instruments in the article. According to this study, the most effective pulse oximeters for 24/7 monitoring of lung function were selected.