Manikins with human-like chest properties--a new tool for chest compression research

Commercially available training manikins for cardiopulmonary resuscitation (CPR) do not accurately mimic the mechanical properties of human chests. This may limit the usefulness of CPR research performed on such manikins. This paper presents the construction of manikins with chest properties matching those measured in patients during an ongoing CPR. The chest stiffness and damping of 59 cardiac arrest patients was measured during out-of-hospital CPR, using a defibrillator with a compression sensor with built-in force sensor and accelerometer. A manikin with eight interchangeable chest force-depth profiles, representing the measured range of chest stiffness and the average damping of these patients, was then specified and constructed. The stiffness and damping of the manikins were verified using the same equipment and method as was used during data collection. Between 30 and 50 mm compression depth, the force-depth relationship of all eight manikins were found to be within +/-30 N of force or +/-2 mm of depth from the reference specifications derived from measurements on patients' chests. The average damping was also found to closely match the specified value.