Abstract: A water well filter device and a method for preventing airborne microorganisms from entering into a water well are disclosed. The water well filter device of the present invention contains a microorganism filter element having sufficiently small pore sizes to stop microorganisms from passing through. The water well filter device can further contain a pre-filter, a vacuum relief valve, or both. The method for preventing airborne microorganisms from entering into a water well involves connecting the water well filter device of the present invention to an opening of the well that is otherwise sealed from open air.

Abstract: A water well filter device and a method for preventing airborne microorganisms from entering into a water well are disclosed. The water well filter device of the present invention contains a microorganism filter element having sufficiently small pore sizes to stop microorganisms from passing through. The water well filter device can further contain a pre-filter, a vacuum relief valve, or both. The method for preventing airborne microorganisms from entering into a water well involves connecting the water well filter device of the present invention to an opening of the well that is otherwise sealed from open air.

Abstract: A prosthetic joint such as a hip prosthesis includes a semipermeable membrane to encapsulate articulating surfaces of the joint. The semipermeable membrane permits circulation of natural body fluid to the articulating surfaces of the joint for lubrication purposes, while preventing systemic distribution of particulate generated at the articulating surfaces in the course of normal mechanical wear. In addition, the membrane isolates the articulating surfaces from other particulate debris, such as fragments of bone cement and/or bone ingrowth materials associated with the prosthesis-bone interface. One or more stay rings are carried by the membrane to prevent the membrane from becoming entrapped between articulatory surfaces of the prosthetic joint.