Abstract: A flexible plastic cannula for use in directing liquid to or from the suprapatellar pouch during arthroscopic knee surgery. The cannula is comprised of a flexible elongated stem, a valve housing and an attachment means, all molded in a single piece of high density polyethylene. The stem is tapered along its length so that the end nearest the valve housing is relatively rigid, while the distal end is narrower and more flexible. The flexibility of the cannula stem is sufficient to allow it to bend with the knee during the arthroscopic surgery.

Abstract: A preventative device against nuisance from birds comprised of a base to which spikes are fitted vertically on the side opposite surfaces of a structure to be protected in order to discourage birds from landing on those surfaces. The base is provided with canals, and each spike has a protuberance obtained by flattening the material of which it is made. The protuberance is slightly larger than the cross section of the canals. The spikes are force fit into the canals so as to be held firmly therein. In an embodiment of the invention, the base of the device is made from polymethylmethacrylate. In another embodiment, the adhesive used to secure the base to the surface being protected is a neutral silicone adhesive.

Abstract: A system for electrically heating a volume of windshield cleaning fluid in a motor vehicle includes a metallic vessel connected between a windshield fluid reservoir and a nozzle for spraying the windshield with the fluid. The vessel has a metal heater wall heated by PTC thermistors thereon and provided with a plurality of metal heat exchange pins extending into an internal chamber in the vessel through which the fluid flows to be heated. A control circuit is provided and includes an electronic timer circuit for controlling the length of time the thermistors are energized to heat the fluid in accordance with the prevailing ambient temperature, an engine speed sensor including a pulse stretching circuit for preventing energization of the thermistors if the engine of the vehicle is not running, and a differential input circuit for simplifying the attachment of the system to a standard windshield cleaning fluid pump.