Abstract: A catheter (1) is disclosed which has a primary balloon (2) to be inflated or deflated, a pumping means (3) for pumping a working fluid into and out of the primary balloon (2) to inflate or deflate it, and a restraining mechanism (4) to keep a first part (5) of the primary balloon (2) or an opening (7) of the primary balloon (2) in a restrained position until a pressure inside the primary balloon (2) is within a predefined threshold and in an expanded position when the pressure inside the primary balloon (2) surpasses the predefined threshold and until the pressure inside the primary balloon (2) gets below the predefined threshold. This helps in retaining the working fluid inside the primary balloon (2) until the pressure is within the threshold, and to move it out of the balloon when it is beyond the threshold.