[Lever type push-pull device for ACD-CPR].
Prolonged use of the CardioPump can cause fatigue and may impair performing the ACD-CPR maneuver accurately. We applied a lever mechanism to lessen the fatigue. The fixed part of the lever consists of a 40 cm metal pipe, 2 cm in diameter, mounted vertically to a rectangular metal base plate (45 cm x 20 cm) placed under the patient when the device is used. The fulcrum of the lever is positioned at any height on the vertical tube. One end of the 65 cm lever was connected to a pin-joint hub at the fulcrum. The height of the fulcrum is adjusted for each patient according to the anterior-posterior dimension of the thorax. The Cardio-Pump is mounted in a frame which is movable along the shaft of the lever between the fulcrum and the handle at the operator end of the lever. ACD-CPR is performed by lowering and raising the handle. The range of motion is controlled for safety by observing the movement of the chest wall of the patient from the side. We were able to maintain ACD-CPR with this device for more than 30 minutes without significant fatigue.