Foam formation device and method

A handheld device for mixing a liquid and a gas to form foam before a treatment procedure, the device comprising:

• an inlet adapted to be attached to an opening of a first syringe containing a liquid for letting said liquid enter the device from the first syringe;
• an outlet for letting a formed foam exit from the device into a member of a group consisting of an opening of a second syringe, a needle, and a catheter;
• a chamber containing a gas, the chamber comprising the inlet and the outlet;
• and
• a plurality of agitation elements disposed in the chamber and connected to one another by at least one wire, the plurality of agitation elements being arranged for independent movement in at least one degree of freedom, the plurality of agitation elements sized and shaped to mechanically agitate liquid flowing past the plurality of agitation elements, the liquid flowing in an overall inlet-to-outlet direction, the agitation being sufficient for at least some of the liquid to mix with the gas to produce the formed foam;
• wherein the device is dimensioned so as to be held in one hand.