Abstract: A powerline communication system comprises a master and slave configuration in which the master provides both operating power and control commands to the slave over a single pair of wires. The slave, in turn, is able to communicate its status to the master with a return communications channel on the same pair of wires. Each sender impresses its signals on the power lines with an isolation transformer coupled to the gate of a power MOSFET transistor that shunts the power lines. Each receiver samples the signals from the sender with an isolation transformer that has its primary winding placed in series with the power lines. The master initiates a synchronizing pulse and places data in various timeslots. The slave follows with an initiating sync pulse followed by data in a group of timeslots. Edge-detection, rather than level-detection is used at the receivers for added immunity to supply and load changes. A double-pulse sync is used for special time slot reporting.

Abstract: The ultrasonic instrument includes a shaft having an integral sheath of PTFE encompassing the shaft and attached solely to the shaft. At the proximal end of the shaft, wrench flats are exposed through openings in the sheath and grooves cooperate with complementary ribs on the sheath, to prevent relative longitudinal and rotational displacement of the sheath and shaft. The sheath is in contact with the shaft at the nodes along the shaft. The diameter of the sheath is about 5 mm whereby the instrument may be used with a 5 mm trocar port. To manufacture the instrument, the sheath is initially formed to a diameter equal to or less than the diameter of the shaft and then mechanically expanded. Subsequently, the sheath is heat-shrunk about the shaft and rolled continuously along the shaft, except at regions corresponding to the nodes along the shaft, to expand the sheath to a larger diameter to space the sheath from the shaft except at the nodes of the shaft.

Abstract: Disclosed is a ultrasonic scalpel blade with a hook and having flat, non-sharpened, relatively dull edges to improve ultrasonic coupling to adjacent tissue and afford exceptional coagulation and hemostasis. The blade with hook is particularly useful for cutting loose, unsupported tissue by grasping the tissue with the hook portion and tensioning it while cutting. The blade affords improved coagulation and hemostasis in loose, unsupported tissue, while simultaneously providing an improved cutting action.

Abstract: An ultrasonic surgical apparatus includes a surgical instrument having a handpiece with a transducer for converting an electrical signal into longitudinal vibratory motion of a blade connected to the handpiece and an accessory releasably connected to the handpiece to enable clamping of tissue against the vibrating blade to afford improved coagulating and cutting of tissue. Scissors-like grips actuate a pivoted clamp jaw along one side of the ultrasonically vibrating blade to compress and bias tissue against the blade in a direction normal to the direction of longitudinal vibratory movement. The clamp jaw and blade are rotatable relative to one another to align a selected blade edge of a multi-edged blade with the clamp jaw for cutting and coagulating while clamping or circumferentially spacing a selected blade edge from the clamp jaw for cutting and coagulating without clamping.

Abstract: Ultrasonic blade coupler comprising a blade element composed of a material selected from aluminum and titanium rendered sharpenable by a surface hardening treatment. The blade coupler exhibits improved acoustical properties with reduced energy consumption.

Abstract: An apparatus and method for reading a bar code marked on a surface of an item, such as a semiconductor wafer, an improved method for marking the surface and an easily decipherable bar code system are disclosed. The apparatus comprises a collimated light source, a beamsplitter, a first lens system, a second lens system, an image screen and a detector. The method comprises the steps of illuminating the bar code by directing the collimated light perpendicular to the surface, magnifying the coaxial reflected beam, projecting the reflected beam on the image screen and reading the projected image with the detector. The improved method for making the bar code marks on the surface comprises the steps of rotating a diamond impregnated nickel blade, decreasing the relative distance between the surface and the blade until the blade contacts the surface, increasing the relative distance between the surface and the blade, and repeating this process until the desired number of bars are obtained.