The concept of a medical robot constructed by parallel mechanisms for chest compressions in rescuing a patient is proposed in this paper. In light of the requirements of cardiopulmonary resuscitation (CPR) from medical aspects, a new translational parallel manipulator (TPM) employing the architecture of a modified version of DELTA parallel robot is designed, which utilizes an architectural optimization methodology for such applications. The mobility and velocity analysis of the manipulator is carried out in details. By introducing a simplifying hypothesis, the inverse dynamic modeling is performed based upon the principle of virtual work. Moreover, the dynamic control using computed torque method is implemented, and simulation results illustrate the well performance of the control algorithm. The research works lay a sound foundation on developing a medical robot prototype to assist in CPR operation.