Abstract: The present invention provides a new method to alert the computer operator to events. The inventive device includes a computer, the computer sound file, an audio connection, and an alerting device. The computer will preferably present text, graphics, video, animation, and sound in an integrated way. In addition, it will play operator-selectable sound files in response to an event. A sound file comprises a quantity of data that may be decoded as an audible sound. For this invention, the sound file will additionally contain a distinct sound known as a trigger-sound. The alerting device plugs into the audio-output port on the computer and allows the speakers to be connected inline. The alerting device selectively activates on computer output of the trigger-sound to gain operator attention. Example alerting devices include: a wireless pager, incremental counter, an animated figure, or a flashing light.

Abstract: A pulsating impeller system is provided for moving a body through a fluid medium. The pulsating impeller includes an enclosure mounted on a vessel or other body. The enclosure is provided with an inlet-outlet aperture to facilitate the flow of the fluid medium into and out of the enclosure. An expansible membrane is positioned in the enclosure. The volume of the expansible membrane is inflated and deflated on a regular cycle by a compressed air or other similar system in the vessel. When the enclosure is placed in a fluid, such as water, and the expansible membrane inside the enclosure is inflated, the volume of the membrane is increased, which results in the water being forced through the outlet hole in the enclosure to propel the vessel. This force will generate a reactive force which will thrust the enclosure and vessel in the opposite direction. The vessel may be provided with a plurality of enclosures, and each enclosure may have one or more expansible membranes.