Abstract: Disclosed is a system and method for suppressing rotor noise by distributing mass and momentum sources and sinks on the rotor blade. A source is located on the blade, and therefore has the directivity of moving, as opposed to a stationary source. Moreover, the motion of the blade with respect to the observer amplifies the sound from the source in a manner similar to the manner in which motion of the blade amplifies all other sources of noise associated with the rotating blade. Two sources can be used to cancel noise. The first source, created by ejecting air from or drawing air into the blade, is used to cancel the "load" portion of rotor noise. The second source, created by developing a radial force with a proplet, is used to cancel the "thickness" portion of rotor noise. More control can be achieved by time modulating the rate of suction or the amplitude of radial force developed by said proplet.

Abstract: Disclosed is a double balloon multiple lumen nasobiliary occlusion catheter including two inflatable balloons positioned about the distal end of the catheter. The catheter comprises several lumens which are used for inflating and deflating the balloons, venting bile, and infusing and aspirating a dissolution solution. When inflated, the balloons occlude the lumen of the bile duct at two points thereby creating a sealed space between the balloons into which a treatment solution may be infused. Since this space is sealed from the remaining biliary tree, the treatment solution will find access to the gallbladder and any stones therein via the cystic duct with the exclusion of bile from the gallbladder fundus, or it will be confined in high concentration around bile duct gallstones located between the inflated balloons. While the treatment solution is applied to the gallstones, bile is excluded from the treatment site.

Abstract: The liquid chromatograph detector of the present invention includes a nozzle communicating with a liquid chromatograph column. A piezoelectric element is firmly affixed to the nozzle and is actuated by an alternating current of a frequency appropriate to cause the firing of charged droplets of a predetermined, uniform size from the nozzle. The emitted droplets pass between two planar deflector plates which are maintained at a DC voltage sufficient to produce a transverse electric field between the plates. The electric field causes droplets passing between the plates to be deflected towards one of the plates and away from the other in a manner and to a degree sensitively dependent upon the charge acquired by the droplet upon discharge from the nozzle. A moving recording medium, such as paper, is positioned to receive the droplets passing between the deflector plates. If necessary, the recording surface is then processed so as to make the impinging droplets visible.

Abstract: Disclosed is an apparatus and method for controlling the cursor of a computer display. The apparatus includes a headset which is worn by the computer operator and an ultrasonic transmitter for transmitting sound waves which are picked up by the receivers in the headset. These sound waves are compared for phase changes, and circuitry is provided for converting the phase changes into position change data which is used by a computer to control the cursor.

Abstract: A flow-through filter including a two-stage valve head assembly and a filtering body which is designed to provide a helical flow path for the solution over a cylindrical porous filter which captures the particulate matter contained by the solution being filtered. An extended filtering capacity is achieved due to the ability of the filter to remove and eject separated solids retained by the porous filter. An expander tube is positioned within the filter and, when connected to a pressure source, the expander tube forces solids from the pores and into the primary volume of the filter where a flushing medium is circulated. The filter clearing is made possible by an accurately controlled and metered volume of uniformly distributed reverse flow which effectively lifts the solid material out of the pores.