how to create isolate function with BLoC

Question

I have a BLoC with an event that repeats every second.

How I can move function in a different thread?

I would use an isolate but I can't find examples that work with this code

class ScanBloc extends Bloc<ScanEvent, ScanState> {
  Timer? _timer;

  ScanBloc() : super(ScanningState()) {
    on<StartScanEvent>((event, emit) {
      _startTimer();
    });

    on<StopScanEvent>((event, emit) {
      _stopTimer();
    });
  }

  void _startTimer() {
    _timer = Timer.periodic(Duration(seconds: 1), (_) {
      //My function
    });
  }

  void _stopTimer() {
    _timer?.cancel();
    _timer = null;
  }

  @override
  Future<void> close() {
    _stopTimer();
    return super.close();
  }
}