Infusion of drugs

A method of replenishing a system for injecting a substance into the patient's body, when the system is implanted in the patient's body, wherein the system comprises:

• an infusion device for injecting a substance into a part of the body of the patient, wherein the infusion device comprises at least one infusion needle disposed at least partly within at least one housing having at least one outer wall, wherein the at least one infusion needle is arranged for penetrating the at least one housing's outer wall in at least one penetration area,
• at least one drive unit coupled to the at least one infusion needle and arranged at least for advancing the tip end of the at least one infusion needle so that the at least one infusion needle penetrates, upon advancement of the tip end or ends thereof, the housing's outer wall,
• at least one reservoir comprising at least one compartment which accommodates and preserves or is adapted to accommodate and preserve the substance to be injected, the reservoir being adapted for implantation inside the patient's body in fluid connection with the infusion device to supply to the infusion device the substance to be injected into the patient's body, and
• an active cooling device adapted to cool the reservoir and thereby keep the substance within said at least one compartment of the reservoir at a temperature below 37º C,
• the method comprising the step of:
• replenishing the implanted reservoir by a replenishing needle penetrating the patient's skin and injecting infusion liquid comprising the substance through the replenishing needle directly or indirectly into the reservoir.