housing 16 in an unimpeded manner the ultrasound leaves the transducer housing 16 through an acoustic window 24 which provides very little disruption in the ultrasound beam to maintain the transducer housing 16 and particularly portions of the transducer housing 16 in contact with the patient at body temperature heating cooling coils 28 are placed in the water coupling mechanism surrounding the transducer the ultrasound irradiator used for closed chest application of ultrasound contains all the features described previously in addition a focussing element 30 of acrylic or other suitable material is placed in front of the transducer 12 to focus the ultrasound to a point within the water bath coupling medium adjacent to the acoustic window 24 this feature provides a narrow beam to pass through small spaces between bones yet the beam expands to irradiate a large portion of the heart in practice the acoustic window 24 in the transducer housing 16 must be in physical contact with the heart 34 or the abdomen not shown respectively in order that ultrasound may be transmitted the ultrasonic transducer device 10 fig1 and 2 is coupled to the myocardium in such a way that the transducer does not exert pressure on the.