Abstract: A prosthesis that replaces the articulating surfaces of the knee joint with mechanical devices which are designed to reproduce its function. A portion of the lower end of the femur is removed and replaced by a cap while the upper tibia is cut off and replaced by a tibial plateau. The articulating surface of the patella is modified to permit fixation of a third component which articulates with a groove in the anterior part of the femoral cap.

Abstract: Mask includes support member with head band arranged horizontally to fit head of wearer. Conduit sections are secured to each side of support member, and flexible ventilation conduit is connected to exhaust means. Transparent face plate is held to support member in spaced relation to wearer's head. Aperture means in conduit allow ingress of air, and exhaust means connected to conduit sections exhaust air from ventilation conduit and interior of mask. In one form, means in upper portion of face plate admit airflow and direct it down over inner surface of face plate to prevent fogging. Hood of air-impermeable material fits over head and shoulders. Gown of similar material over body and lower part of hood and tied at neck completes assembly. Any leakage is that of sterile air from exterior to interior of mask because of continuously operating exhaust system.