A system for testing a helmet includes a simulated skull comprising a cranial cavity; a brain surrogate disposed inside the cranial cavity; and a cell pack comprising at least one culture well suitable for three-dimensional growth of live neurons therein, the cell pack comprising a retaining plate having at least one opening exposing a portion of a flexible membrane containing the at least one cell culture well, the exposed membrane portion being substantially flush with an exterior surface of the retaining plate, wherein the brain surrogate is configured to closely surround the cell pack inside the simulated skull. Also disclosed is a method of using the system.