Abstract: Processing waveform data for compressed display. A parameter to be displayed is measured, digitized, and displayed on a device that does not permit display of all of the data samples; thus, the digitized data is converted to a compressed form. For a compression factor of N input samples for each displayed sample, a displayed sample is taken from each successive group of N input samples. The choice of input sample is as follows: the sample having the maximum value of the group is chosen if all of the samples of the group are greater than or equal to the previous displayed sample; if all of the samples of the group are less than or equal to the previous displayed sample, then the sample having the minimum value is chosen; if the maximum and minimum values of a group straddle the value of the previous displayed sample, then a maximum sample and a minimum sample are chosen from the combination of that group and the next group. The technique can be applied in situations where N is not an integer.

Abstract: A cap for sealing pressure vessels is disclosed. The present invention permits a nominal closure to be formed by hand tightening and a substantially higher force to be applied to a cap by a separate clamp mechanism, thereby forming a pressure seal. In certain preferred embodiments, means for providing a process flow through a hole in the seal and filtering means are also provided as part of the cap assembly. A preferred application of the cap of the present invention is for the sealing of sample vessels used for supercritical fluid extraction of compounds from a solid matrix for subsequent chemical analysis. Methods of supercritical fluid extraction are also disclosed. The present invention thus provides methods and apparatus whereby the placement of a sample into a pressurized system may be automated and monitored to ensure adequate seals have been created and maintained within such pressurized systems.

Abstract: A method and apparatus for accurately regulating the compressibility of a compressible fluid in a thermoelectrically cooled pumping system having a first heat exchanger for precooling the compressible fluid utilizing cooled fluid which has been outputted from the pump and a second heat exchanger, coupled to the pumphead which incorporates thermoelectric cooling elements, for cooling the compressible fluid immediately prior to being pumped.

Abstract: A valve assembly is provided for controlling pressurized inputs from two separate fluid sources, and in particular to provide enhanced isolation between the sources and to buffer short-term fluctuations in fluid flow. A high pressure chamber is provided which is separated into two chamber portions by a fluid-impervious flexible membrane. A valve, such as a ball valve, having a movable member is positioned in an inlet port in each channel portion, fluid flowing, for a preferred enbodiment, from a fluid source under pressure through the inlet port of a chamber portion, an output port in the portion and a restrictor to a mixer. A pressure differential in the chamber portions deflects the diaphragm to bear against the movable member in the lower pressure chamber portion, closing the valve for this chamber portion before the pressure is sufficient to result in any backflow therethrough.

Abstract: A solenoid driven valve is disclosed which is adaptable for controlling the introduction of a high pressure fluid into a fluid trapping assembly having an absorption column topped with an annular orifice expansion nozzle. The valve has an inlet port to introduce high pressure fluid, an axially moving solenoid driven pin which engages means to restrict fluid flow into said column. A diaphragm is located within the valve to direct fluid into the column and which separates the fluid in a region of high pressure from ambient pressures.

Abstract: An efficient cache write technique useful in digital computer systems wherein it is desired to achieve single cycle cache write access even when the processor cycle time does not allow sufficient time for the cache control to check the cache "tag" for validity and to reflect those results to the processor within the same processor cycle. The novel method and apparatus comprising a two-stage cache access pipeline which embellishes a simple "write-thru with write-allocate" cache write policy.

Abstract: A multislope continuously integrating analog-to-digital converter for converting an analog input signal into a digital output signal where the converter employs an integrator for continuously integrating the input signal in relation to a series of reference voltages of increasing magnitude and a zero crossing detector to determine when the reference voltage has completely discharged the integrator. A counter or the like is employed for timing the duration of the discharge which corresponds to the digital equivalent of the analog input signal.

Abstract: A method and apparatus for accurately regulating the compressibility of a compressible fluid in a pumping system utilizing a single zone of controlled cooling. Cryogenic cooling is employed for cooling a pump head and a thermally integrated heat exchanger such that a single source of cryogenic fluid can be applied to the heat exchanger to increase the bulk modulus of the compressible fluid just prior to and during the pumping process.

Abstract: A delay circuit for producing in an electrical circuit a time delay. The circuit includes a pulse generator which produces an edge at a given time interval after an edge is applied to its input. The time interval can be adjusted so that it automatically follows a reference time interval such as a clock period. The circuit has application in the read circuitry of digital tape devices.

Abstract: A method is used for processing signals, particularly for oximetric measurements on living human tissue. Spurious signals are suppressed with respect to information signals. The spurious signals have a frequency lying in a first frequency range, and the information signals have a frequency lying in a second frequency range being different from said first frequency range. The signals are conducted over a filter having essentially a blocking characteristic in said first frequency range and having essentially a transmission characteristic in said second frequency range. An output signal of the filter is further processed.In order to eliminate distorting effects from the filter on the information signal, a first function is determined representing the deviation of the frequency response of the filter in said frequency range from an ideal transmission characteristic. A second function inverted with respect to said first function is generated.

Abstract: The invention is a method and apparatus for significantly improving the performance of a reciprocating pump by delivering the pumping fluid at a desired pressure and flow rate with minimal flow fluctuations. The compressibility of the pumping fluid directly effects volumetric flow rate and mass flow rate. The method includes the step of sensing various pump parameters related to said compressibility and adjusting the pumping speed to make appropriate accommodations. In particular, the compressibility of the pumping fluid is effected by the adiabatic heating of the pumping fluid during compression, variations in pumping fluid density, leaks in the check valves of cylinder/piston seals and the primary and secondary switching losses in the fluid flow occurring when the primary and secondary pistons reverse direction.

Abstract: A system for quadratic and higher order interpolation of pixel color and other pixel values into a bitmap image enables enhanced shading for generation of realistic computer graphics images. The system incorporates modules for executing incremental evaluation of pixel values, utilizing forward differencing in N arbitrary directions of incremental evaluation. The system alternatively incorporates non-incremental evaluation elements for directly evaluating polynomials or executing a spline function of control points.

Abstract: A fault tolerant power supply comprises a first rectifier and a second rectifier with a boost circuit for correcting line current harmonics. The second rectifier, the boost circuit and output diodes are connected in parallel with the first rectifier. A capacitor circuit is charged through the second rectifier and boost converter when a 240 volt line input is present, but the circuit is charged through the first rectifier when a 120 volt line input is present. With failure of the boost converter circuit or with removal of the boost converter circuit from the system, the capacitor circuit is charged through the first rectifier.

Abstract: Methods and apparatus for extracting sample components from complex matrices using supercritical fluid as the principal extracting solvent are disclosed. The invention takes advantage of the fact that the solvent power of a supercritical fluid is stepwise settable by the parameters of density, modifier concentration, and temperature. Accordingly, methods and apparatus for extracting a component from a sample using fluid flow system having a variable and controllable flow restriction are disclosed. The methods of the present invention comprise the steps of inserting the sample into the sample container section, inputting temperature, pressure, flow rate and extraction time set points. Flow rate is controlled and system pressure regulated by the variable flow restriction.

Abstract: A fault tolerant power supply comprises a first rectifier and a second rectifier with a boost circuit for correcting line current harmonics. The second rectifier, the boost circuit and output diodes are connected in parallel with the first rectifier. A capacitor circuit is charged through the second rectifier and boost converter when a 240 volt line input is present, but the circuit is charged through the first rectifier when a 120 volt line input is present. With failure of the boost converter circuit or with removal of the boost converter circuit from the system, the capacitor circuit is charged through the first rectifier.

Abstract: In a system comprising a plurality of digitally addressable electronic devices, all devices have the same construction and are designed for being connected in series to a common central monitoring station. The addressing of these devices is accomplished by a plurality of address lines which are connected to input contacts of the respective device. Within each device, a selection gate is connected to the input contacts which provides an enabling signal if the signal on said address lines has a predetermined bit pattern. Each device has output contacts connected to its input contacts to which the input contacts of a next device are connected. The address lines are connected from the input contacts to the output contacts of the device in such a way that the contacts are interchanged, and an inverter is inserted in one of said lines so that the bit pattern forming the address provided at the output contacts is different from the bit pattern received at the input contacts.

Abstract: An apparatus and method are disclosed for an IV pump which can act also as a passive infusion controller. The apparatus has a disposable flow chamber with two pumping subchambers connected by a first collapsible passageway. A pump drive is used to operate the pumping subchambers and includes a first control valve for depressing the first collapsible passageway to control flow between the subchambers and an outlet control valve for depressing an outlet collapsible passageway to control flow of infusate out of the flow chamber. The flow chamber has a base surface and first and second caps, each cap being spaced apart from the base surface and having means for attachment to one of two moveable connector rods. The caps each act as one side of the first and second pumping subchambers, respectively, the base surface being the other side. A flexible wall is connected to the base surface and to each of the caps providing the subchamber volumes therebetween.

Abstract: An input device, in particular for a medical monitoring system, comprises a keyboard, a screen and a control processor. The keyboard comprises various hardkeys enabling access to an object mode in which the user may enter an object to be manipulated. Once an object is selected, the device enters a task/action mode in which the user may define an action to be performed on the selected object.

Abstract: Apparatus and method for concurrent dispatch of instruction words which selectively comprise instruction components which are separately and substantially simultaneously received by distinct floating point and integer functional units. The instruction words are powers of 2 in length, (measured in terms of the smallest machine addressable unit) typically a 4 byte longword and an 8 byte quadword aligned to the natural boundaries also corresponding to powers of 2. To provide maximum operating efficiency, each functional (or processing) unit executes a component of an instruction word during an execution cycle. The type and length of the instruction word are indicated by one of the bit fields of the instruction word, which permits the apparatus to properly detect, store and transfer the instruction word to the appropriate functional unit.