Patent ID: 7833321

Claim:
A protective filter for an extracorporeal circulation circuit pressure monitor, having a dialysis device side housing having a lumen penetrating therethrough, an extracorporeal circulation circuit side housing having a lumen penetrating therethrough, and a hydrophobic filter held between the housings, said filter allowing passage of a gas but not allowing passage of a liquid, characterized in that a plurality of ribs capable of supporting the hydrophobic filter are respectively provided in both housings, and a protective member capable of preventing direct contact between the ribs provided in the extracorporeal circulation circuit side housing and the hydrophobic filter is interposed between the ribs provided in the extracorporeal circulation circuit side housing and the hydrophobic filter, the protective member being porous and having pores having a size of 1-100 μm; and the protective member having a thickness of 0.1-1 mm.