Abstract: An elastic cord having at least one tapered protruding portion along its length, wherein the extent of protrusion is reduced when the cord is axially stretched, and returns to its original size when the cord is relaxed, is described. One embodiment includes an elastic core about which a flexible sheath is fitted, wherein chosen axially spaced-apart portions of the sheath form tapered isolates or knots in accordance with selected patterns for protrusions therein when the elastic core is in its relaxed state. Such knots are formed when the sheath is cause to bunch up at these axial locations. Sheath patterns may be achieved by employing a woven structure for the sheath. The protruding portions or knots reversibly resist movement of the elastic cord through an opening having a chosen size, such as an eyelet of a shoe.

Abstract: A particulate monitor includes a housing, an air-moving device coupled to the housing, and an air passageway disposed at least partially within the housing. The air-moving device is operable to create an airflow through the air passageway. The particulate monitor also includes a real-time measuring device positioned at least partially within the housing and in fluid communication with the air passageway and a particulate collection device positioned at least partially within the housing and in fluid communication with the air passageway. The collection device is positioned downstream of the real-time measuring device.

Abstract: A cordage for threading through an opening. An elastic cord is provided with an elongated shank component and at least one outwardly expandable component. When the cord is under tension, the expandable component shrinks to a diameter which is sufficient to enable its movement through an opening, such as an eyelet of a shoe. In response to the tension being released, the expandable component enlarges to a diameter which is sufficiently large to resist movement through the opening.

Abstract: The present invention imports network communication concepts into a motor and/or motion control system. The motor and/or motion control system is divided into various modules. A preferred configuration includes a motor drive control module, a user command module, and a master control module. The modules are interconnected by a simple hardware bus, such as an RS-485 bus. Communication between the modules is accomplished using a time division protocol.

Abstract: An electronic control system for a stair climbing vehicle, such as a wheelchair is disclosed. Front and back sensors are provided for detecting a stairway or slope. The electronic control system determines from the sensor data whether the slope has an acceptable incline for traversing. If it is not acceptable, the vehicle will be prevented from entering onto the stairway or slope. A seat for a user is tilted in accordance with electronic controls to keep the user approximately vertical with respect to gravity as the vehicle traverses the stairs. The allowed operation of the vehicle is controlled via parameters which can be changed by removable memory which configures the vehicle for a particular user or group of users.

Abstract: The present invention provides a sensor for detecting the angle of an incline, such as a staircase, before it is reached by the wheelchair. A control signal is provided to a motor for tilting the seat to cause the seat to be tilted to a predetermined minimum safe angle before the wheelchair reaches the staircase. The minimum safe angle is an angle of tilt at which the wheelchair will not roll over if the tilting mechanism should fail to completely rotate the seat to a horizontal position and as the stairs are descended. The minimum safe angle is determined by the position of the center of gravity of the wheelchair which is affected by the users weight. If the seat does not achieve this minimum tilt, the wheelchair is prevented from going over the stairs.