Abstract: A selected part of or the entire body of a patient on an operating table can be insulated from air in the surrounding atmosphere by a stream of clean-room air which issues from a distributor head and is caused to form a relatively thin layer between the selected part and the surrounding atmosphere. Such relatively thin layer can be established and maintained by heating or cooling the stream so that its temperature deviates from that of air in the surrounding atmosphere by a few degrees centigrade. The direction of flow of a portion of or the entire stream can be changed by one or more secondary streams. The moisture content of the stream of clean-room air can be increased by causing it to flow through a steam chamber. Heating or cooling of the stream can precede or follow sterilization of atmospheric air which is to form the stream.

Abstract: An operation area on an operating table is flanked by a blower unit and a suction unit. The blower unit creates several vertically spaced and independently adjustable streams of gas each of which is aspirated by a respective intake of the suction unit. The lowermost stream of gas, which is sterilized, flows just tangent to the operation location on the body of a patient lying on the operating table. The outlets of the blower unit and the intakes of the suction unit are independently adjustable to position the respective gas streams in accordance with the dimensions of the body part being shielded.

Abstract: An arrangement for preventing access of bacteria and other contaminants to an area in which medical operations are carried out, having first instrumentalities for producing a stream of sterile gas, second instrumentalities for directing the stream tangentially over the area to form a gas curtain which prevents access of contaminants to the area, and third instrumentalities for preventing ambient contaminants from penetrating into the stream of sterile gas.