Thread save UIAutomation problem

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C#

I am attempting to write a console application to Automate an existing GUI application. I am getting the following error when I attempt to select a tree item in the GUI application.

System.Runtime.InteropServices.COMException (0x8001010D): An outgoing call cannot be made since the application is dispatching an input-synchronous call. (Exception from HRESULT: 0x8001010D (RPC_E_CANTCALLOUT_ININPUTSYNCCALL))

Here is the code that selects the tree item:

AutomationElement elementNode = TreeWalker.RawViewWalker.GetFirstChild(SensorTreeCollection);
            SelectionItemPattern selectElement;

            while (elementNode != null)
            {
                try
                {
                    Console.Out.WriteLine("node of type " + elementNode.Current.ControlType.LocalizedControlType + " with name of " + elementNode.Current.Name);
                    sw.WriteLine(elementNode.Current.Name);

                    try
                    {
                        selectElement = elementNode.GetCurrentPattern(SelectionItemPattern.Pattern) as SelectionItemPattern;
                        selectElement.Select();
                        
                    }
                    catch (InvalidOperationException)
                    {
                        return;
                    }    
                }
                catch (Exception e)
                {
                    Console.Out.WriteLine("{0} Exception caught.", e);
                }
                elementNode = TreeWalker.ControlViewWalker.GetNextSibling(elementNode);
            }

From what I can tell the error is occurring because I'm making the change to the GUI application from a different thread and that I need to use a thread safe implementation to do this. Unfortunately, at best I am a threading novice and don't understand how best to do this. Can someone help?

I've expanded the code by including the automation treewalker. The error occurs when the selectElement.select() call is made.

I looked at delegates and the Invoke method but I don't know how to adapt control.invoke() for for use with an AutomationElement. Is there someway to cast an AutomationElement to a control so it can access invoke?