MUNICH — A German judge ordered that the trial of John Demjanjuk go ahead Monday after overruling the defence’s argument the 90-year-old’s health is deteriorating and that he can no longer concentrate on the proceedings.Presiding Judge Ralph Alt ruled that the session should continue after the court doctor said he could see no signs that Demjanjuk’s health had deteriorated.Demjanjuk, who was deported from the U.S. to Germany in May 2009, is being tried on 28,060 counts of accessory to murder over allegations that he served as a guard at the Nazi’s Sobibor death camp in occupied Poland.He denies the charges, saying he never served the Nazis as a guard anywhere. The defence maintains Demjanjuk was a Soviet soldier captured by the Germans and spent most of the war in prison camps himself.Demjanjuk suffers from a number of medical problems, and since his trial began last November a dozen sessions have been cancelled due to health issues.He arrives by wheelchair to the courtroom and lies in a hospital bed during the proceedings, usually wearing dark sunglasses.Defence attorney Ulrich Busch told the court Monday that his condition has worsened, and that he is now in almost constant pain and cannot follow the proceedings, nor read the documents being submitted as evidence.