The Membrane Petri Nets Patient-Specific models, (computational models of human pathophysiology that are individualized to patient-specific data) fruit of an ambitious long-term project developed by a few enthusiastic teachers and students within the Moldova State University, were in need of a theoretical base, a formal model. Given the opportunity, we have developed, for the first time, an instrument – named RPM-PSYS – that would convert Membrane Petri Nets models into P-systems formal models. RPM-PSYS has been used for obtaining P-system models for the Membrane Petri Nets Patient-Specific Models developed up-to-date.