Abstract: A transducer mounting device maintains a transducer at a constant level in relationship to the patient lying on an operating table regardless of any raising, lowering, tilting or rotating of the operating table that may occur during an operation. The transducer mounting device is securely fastened to the frame of the operating table and comprises a bar that includes a horizontal arm portion extending along the side of the table and a vertical arm portion extending upward from the end of the horizontal arm portion to provide a mounting surface for the transducer at the level of the patient's heart. The horizontal arm portion is laterally offset from the frame of the operating table to allow clearance space during the initial orientation of the horizontal and vertical arm portions.