Abstract: A localized clean air system for operating theaters and a method of supplying clean air to a localized region in such situations. A fan is connected to a delivery head, which has an outlet for directing inlet clean air to the localized region in a particular pattern. A streamlined body is positioned in the outlet so that, in use, the clean air flows around the body and is modified thereby to form, immediately downstream of the body, an inner region of low velocity air encircled by an outer region of higher velocity air. Preferably, the streamlined body is symmetrical about its axis and is aligned with the clean air flow, for instance by being centrally positioned in the air outlet. The streamlined body preferably comprises a rounded head and a tapered tail. A diffuser is disposed in the clean air flow upstream of the streamlined body to minimize turbulence in the air flow.

Abstract: A touch sensing direct input data display device is described. The data display screen is directly and solely supported within a housing by stiff springs having essentially uniaxial freedom of motion. Strain gauge sensors are applied directly to the springs and are connected in a full Wheatstone bridge sensing circuit. The outputs of the sensors are fed to a calculating and processing device for calculaating the X, Y and Z coordinate information relative to the point on the face of the display which has been pushed or touched. The Z component is of total force and the X any Y components give the two dimensional location for the application of the force measured in the Z axis. The stiff springs allow very little deflection to occur under normal touch imposed fores on the display screen. They permit essentially uniaxial motion only in the Z axis.

Abstract: A touch sensing display apparatus having improved electrical signal processing is described. A plurality of signal threshold comparison levels are employed by the electronic signal calculating and processing unit to identify actual touch signals and to exclude extraneous vibration and offset signal components. Static thresholds of comparison are utilized at lower signal levels and a dynamic, signal tracking threshold is utilized at higher signal levels. The apparatus is particularly effective for use in designs employing a suspended CRT display or other display device in which the screen of the display device is directly touched by a user to record selections of information presented or to input graphical or handwritten information.

Abstract: A piezoelectric touch screen assembly can be attached to mounting ears on an ordinary CRT assembly. The touch screen assembly includes a frame, a glass plate which is seated on a gasket at one surface of the frame and a plurality of piezoelectric elements which are bonded to the glass plate and are "trapped" between the CRT face and the glass plate. Studs extend outwardly from the CRT ears through openings in the frame. Coil springs are placed on the studs and are trapped by washer nuts to load the touch screen assembly toward the CRT by a predetermined amount. Grommets with a unique cross sectional configuration are mounted at the openings through the frame. The grommet is designed to provide minimal resistance to movement of the touch screen assembly toward or away from the CRT face but greater resistance to movement of the assembly in other directions.

Abstract: An implant of H shape for use in bone surgery, specifically in re-attaching the greater trochanter after osteotomy. The cross-bar (28) of the H forms a bridge and has two longitudinal holes (24) in it for receiving a tying cable (22). At each end of each limb (32, 36) of the H there is a tooth (34, 38) which is either impaled in, or fits around, the trochanter or other bone. The limbs can be straight in the region of the bridge or can be markedly curved. The teeth all lie on the same side of the structure constituted by the limbs and bridge, and, where the limbs are curved, lie on the inside of the curve.