It is likely to be Saint Kosmas (Косьма). He is seated and several people came to him to be healed. He is wearing clothes that are typical for праведник. And the text reads: 'приведите семо и далее :стый Косьма' which means he is asking for someone to be brought to him to help or heal them. The fact that his name is in the writing gives a good chance of the icon to be a depiction of him.
Saint Kosmas, along with his brother Damian, were third century martyrs known for their philanthropic medical services. Together, they are the patron saints of the medical profession.
We are grateful to our colleague Yuliya Lennon at the Princes Foundation School who identified this scene.