Within the context of medical malpractice, the term “gross negligence” refers to conduct so reckless or mistaken as to render itself virtually obvious to a layman without medical training. Examples include a surgeon amputating the wrong limb or leaving a surgical instrument inside a body cavity of the patient. Some states will permit a person to establish a cause of action for medical malpractice grounded in gross negligence without the need for expert testimony. A minority of states still permit an action for “res ipsa loquitur” (“the thing speaks for itself”), meaning that such an accident or injury to the patient could not have occurred unless there was negligence by the doctor’s having control over the patient.