Needle system for injection and aspiration

A needle system, comprising:

• a needle arrangement including a needle having a first length between a proximal end and a distal end, the distal end of the needle having a needle opening, and a rod having a second length between a proximal rod end and a distal rod end, the second length being greater than the first length, wherein the rod includes an elongated rod shaft portion configured to fit inside the needle and a rod tip portion located at the distal rod end;
• and
• an actuator device, comprising an actuator body defining a cavity having a proximal wall at a proximal end, a distal wall at a distal end, and a first opening configured for fluid connection to a fluid transportation device, to allow fluid to flow into and/or out of the cavity;
• wherein the needle system has a closed state and an open state, wherein the rod tip portion blocks the needle opening in the closed state, and wherein the rod tip portion is shifted distally relative to the needle to unblock the needle opening in the open state;
• wherein the proximal end of the needle is connected to the actuator body and is open to the cavity;
• and
• wherein the rod is configured to interact with the actuator device such that , when the cavity is de-pressurized, the volume of the cavity changes, and a first force is exerted on the rod by the actuator device in a distal direction, setting the needle system in the open state, thereby allowing fluid to be aspirated through the needle.