How to emit a signal from a static function

[buster]

I have been trying to emit a signal from a static function, but get an error message:
error: cannot call member function ‘void MyClass::myStaticFunction()’ without object
emit connectionChanged();
^
The function myStaticFunction() is declared as static because it is a callback function from some processing interface. I have verified that when I do not try to emit a signal myStaticFunction() is duly called. MyClass is derived from QObject:

class MyClass : public QObject
{
Q_OBJECT

I presume there must be a (simple?) solution to this?