Abstract: A sterile zone is provided above a horizontal working surface of a mobile casing by provision of an upstanding top section fitment having perforated walling. A fan inside the casing draws air in through lower inlets, and through filters, and clean air passes out via the perforated fitment walling. A major portion of the air flow is preferably directed across the working surface by provision of larger perforations in the fitment wall region which faces that surface and/or by provision of curving air deflector plates inside the top section. Airflow at a lower level from the remainder of the top section prevents any inflow or entrainment of contaminents to the sterile zone.

Abstract: A sleeved gown is formed with an integral hood having a narrow front opening in line with the eyes of the wearer. The material of the gown is held in close contact with the wearer's face across the forehead and below the eyes but above the nose by means of tapes tied around the hood. An exhaust duct extends over each of the wearer's shoulders beneath the gown and has a plurality of exhaust inlets in the region of the wearer's chest. Preferably, upward airflow is restricted to a vertical passageway formed by an outward billowing of the gown material. This arrangement is most effective in drawing away air-borne emissions from the wearer's body and causing ambient air to enter from the bottom of the gown and gaps at each side of the wearer's nose. It is more comfortable than previous arrangements as there is no rigid mask or visor. Also as air extraction does not take place adjacent the wearer's face, no special communication equipment is required.

Abstract: A table top is provided, at least along one side, with a number of sockets into which air entry devices or blanking units are fitted, as required. In use the air entry devices project above the table top and have openings facing inwardly of the table top. The sockets lead to an exhaust duct and when a body lying on the table top is being dissected, an extractor fan located in the duct is switched on to draw air across the table top, into the devices and through filters for exhaustion via the duct. This pattern of air flow minimizes the likelihood of an operator inhaling noxious substances or gases from the body, and the devices do not impede access to the body by the operator.The air entry devices may be slideably adjustable in the sockets or else provided in a range of lengths and be interchangeable so that they can be arranged at optimal levels above the table top.

Abstract: A sterile air trolley introduces sterile air into a zone adjacent all outermost boundaries of an upper part of a casing which extends laterally outboard of all sides of a lower part of a casing. The sterile air so introduced is without or free of any contaminated ambient air being entrained by the air so being emitted from the trolley and so introduced into the zone.

Abstract: Apparatus for generating a clean air zone, for example around a patient undergoing surgery or for a pharmaceutical or electronic clean room, has air supply means and air delivery means, inlets to the air supply means being distributed about the periphery of the apparatus so that clean air issuing from the delivery means travels first away from the delivery means, next outwardly from the center of the zone and finally inwardly to the inlets, thus sweeping an area larger than the size of the apparatus, and obviating the need for the apparatus to clean large quantities of ambient air.