This automated, portable, battery- or AC-powered solution provides adult victims of sudden cardiac arrest (SCA) the precision needed for high quality and continuous chest compressions associated with better survival. With an innovative and elegant design, the ARM is easy to deploy and use. Using a proprietary algorithm, the removable compression module delivers smooth and consistent compressions, with complete chest recoil, as recommended by AHA/ERC cardiopulmonary resuscitation (CPR) guidelines. A rigid backboard with a stiff frame of single-piece design facilitates operation without unwanted flex.