Although Arizona officials have claimed that Joseph Wood was "brain dead" during his two-hour execution on July 23, prominent medical experts from around the country strongly disagreed. David Waisel, associate professor of anaesthesia at Harvard medical school, said a person who is brain dead will stop breathing unless kept alive on a ventilator. “There is no way anyone could ever look at someone and make that kind of diagnosis. He was still breathing, so he was not brain dead. This is an example where they threw out a term that has a precise medical definition, but they didn't know what it means.” Dr. Chitra Venkat, clinical associate professor of neurology and neurological sciences at Stanford University, said, “If you are taking breaths, you are not brain dead. Period. That is not compatible with brain death, at all. In fact, it is not compatible with any form of death.” And Dr. Robert D. Stevens (pictured), associate professor at Johns Hopkins University School of Medicine, noted, “Any type of breathing, gasping, whatever it is, immediately indicates that the patient is not brain dead.” Columbia University anesthesiologist Mark Heath called the use of midazolam (part of Arizona's lethal injection regimen) "a failed experiment."