Sealed two-way magnetic manifold

A computer software product, operated in conjunction with a probe that is configured for insertion into a body cavity of a patient, the probe comprising a handle, and an insertion tube having a distal end and an insulating sheath, the insertion tube comprising:

• an inlet tube configured to receive an irrigation fluid from a pressurized fluid source,
• at least first and second outlet tubes configured to deliver the irrigation fluid to respective outlets of the probe,
• a manifold containing a chamber coupled between the inlet tube and at least the first and second outlet tubes,
• a ball comprising a magnetic material contained inside the chamber,
• a plurality of ablation electrodes, the electrodes comprising thin metal layers formed over the insulating sheath of the insertion tube, wherein the respective outlets are connected to respective apertures of the ablation electrodes, and
• a magnetic field generator disposed outside the chamber,
• the product comprising a non-transitory computer-readable medium, in which program instructions are stored, which instructions, when read by a computer, cause the magnetic field generator to generate a variable magnetic field within the chamber so as to move the ball between at least a first position in which the first outlet tube is blocked, a second position in which the second outlet tube is blocked, and a third position, in which neither of the outlet tubes is blocked.