A Wireless Closed‐Loop System for Real‐Time Hemorrhage Monitoring and Autonomous Thermal Hemostasis

Failure of hemorrhage control during dynamic transport remains a critical challenge in prehospital trauma care. While various advanced biomaterials have been developed to facilitate hemostasis, their therapeutic actions are largely passive and open‐loop. Here, we present a wireless closed‐loop hemostatic system enabling real‐time hemorrhage monitoring and autonomous thermal hemostasis. Within the system, a conductive chitosan‐dopamine/PEDOT:PSS/graphene cryogel converts blood infiltration and clot disruption into characteristic resistance signatures while conducting heat to the wound. These signals are processed by miniaturized wireless electronics to enable rapid identification and quantification of repeated bleeding and blood loss, while on‐demand thermal actuation accelerates coagulation cascades until clotting is restored. In vivo evaluations demonstrated that this strategy reduced primary blood loss by 70%–80% and secondary bleeding by >65% compared with standard dressings, with histological confirmation of minimal thermal damage and normal tissue repair. This work establishes a self‐regulated sensing‐treatment paradigm for preventing secondary hemorrhage and autonomous intervention.