Abstract: In a digital text-to-speech conversion system of the type usually contained in all-software form on a floppy disk, memory requirements for the storage of digitized waveform samples are reduced while speech quality is improved, by providing compression techniques and anti-distortion techniques which interact to provide clear speech at widely varying speeds with a minimum of memory. These techniques include using Huffman coding of first- or second-order differences, encoding only differences between successive waveforms where feasible, using a demi-diphone organization of the speech to allow use of the same instruction lists for several sounds, selectively deleting or repeating waveforms in the concatenation to vary speed without affecting pitch, and encoding waveforms linearly or anti-logarithmically for storage while converting the stored linear or anti-logarithmic codes to logarithmic codes such as .mu.-law codes upon retrieval.

Abstract: An in-room sharps container for hospital rooms and the like provides superior safety, versatility and economy by featuring a tapered, stackable body with a permanently hinged cover which is irreversibly interlockable with the body and which carries a semicylindrical dome covering the major portion of a pivotable semicylindrical dump tray. The dump tray can be permanently locked for disposal of the container by an over-center biased pin which locks the dump tray in the closed position. A stepped notch is provided in the cover above the tray for unscrewing and dumping blood collection needles without touching them. Hollow carrying handles protect personnel from contact with contaminants on the exterior of the container when it is being carried.

Abstract: The outside diameter of an intravascular axial flow blood pump is reduced without reducing the size of its journal bearings by causing the pumped blood stream to exit through apertures in the cylindrical outside wall of the pump housing between the rotor blades and the rotor journal. This allows the journal to have a diameter of the housing, without the need for a space-consuming blood flow path around the journal.

Abstract: Speech analysis is performed by synchronizing, with the initiation of glottal pulses produced during the voicing of phonemes, a pitch-independent transform that performs analysis entirely within a pitch period. Analysis is made of the three most dominant formant frequencies of the sound sets involved in the enunciation of voiced phonemes. Peaks in the transform represent formant frequencies. Three peaks are selected from the transform identifying the frequencies with the first, second and third greatest amplitudes. Correlation of the waveform between successive pitch periods detects whether a sound is a vowel, a voiced sibilant, or unvoiced. Unvoiced sound sets are similarly analyzed but the analysis is synchronized with artificially generated synch pulses. The sound sets are analyzed to determine (1) whether the sound is a vowel, a voiced sibilant or an unvoiced sound; (2) the primary formant frequency, i.e.

Abstract: Clear speech can be produced on a DAC-less personal computer from an all-software speech-generating program with an unlimited vocabulary by applying to the computer's speaker a square-wave carrier signal of ultrasonic frequency, and varying the duty cycle of the carrier signal in accordance with digitized speech samples to produce an audio signal. The computations necessary to produce the speech samples are so timed by the program that the CPU is free to turn the speaker on and off between computations at precisely the right instant for the correct generation of a carrier having a constant ultrasonic frequency and a duty cycle determined by the value of the speech samples.

Abstract: Cyclic total parenteral nutrition is safely administered by tapering the infusion rate over a substantial period of time at the beginning and end of the infusion cycle. An infusion pump is disclosed which automatically calculates and performs a cycle profile having an appropriate steady-state rate and appropriate tapers in accordance with pre-established criteria when total volume and total infusion time per cycle are entered. The pump has a sleep mode for energy conservation without loss of memory when predetermined periods of inactivity occur.

Abstract: An automatic signaling arm attachment for a standard rural mailbox with a beveled edge which can be wedged between the door and the sidewall of the mailbox to hold the signaling arm in a generally inconspicuous position alongside the mailbox when the door is closed, and which allows the arm to pivot by gravity to a highly visible position below the mailbox when the mailbox door is opened.

Abstract: An implantable axial flow blood pump maximizes the blood flow while minimizing the dimensions of the pump. By magnetically suspending a rotor of relatively small diameter coaxially in a cylindrical blood conduit of substantially larger inner diameter, an adequate flow area through the pump is provided, and the need for bearings, lubrication and seal purging fluid is eliminated. This is made possible by the use of neodymium-boron-iron rotor magnets which allow a substantial gap between the static motor armature and the rotor. The rotor is simultaneously torqued and maintained in a position coaxial with the blood conduit by individually varying the current in the armature windings while they are being commutated. The position of the rotor axis is accurately sensed by placing magnetically permeable strips into opposite ends of the pump stator blades in such a manner that they transmit to Hall sensors variations in an annular magnetic field surrounding the rotor adjacent the ends of the pump stator blades.

Abstract: A device for dispensing a caked composition into a liquid employs a container filled to a desired level with a cake of the composition to be dispensed, and an upwardly opening vessel over which to place the container telescopically so that the cake surface is disposed over the vessel mouth. A support structure is included upon which the vessel is mounted in a position enabling placement of the container over the vessel, the support structure serving to support the vessel so that the vessel mouth is facing upwardly and the rim portion is disposed horizontally. Liquid coupling components couple a flow of liquid from a separate source through an inlet opening in the vessel, so that with the cake surface disposed over the vessel mouth, the liquid fills the vessel, washes across the cake surface to dispense the composition from the cake, and then discharges over the rim portion.

Abstract: A system includes a power supply unit adapted to provide power from a separate backup source of power to a computer in the event of an interruption in a primary source of power, the unit having a size and shape adapted to be set on a support surface in a position above a keyboard utilized to provide input to the computer. An illumination panel, including at least one lamp on the power supply unit, illuminates the keyboard when activated, and a control circuit activates the illumination panel utilizing the backup source of power when there is an interruption in the primary source of power.

Abstract: A plurality of infusion pump modules are detachably connected to a portable central management unit. The modules can be programmed by the central management unit, and their operating information displayed by the central management unit, when they are connected to it; yet the modules, once programmed, can operate independently when detached from the central mangagement unit, and they can display limited operational information on their own.

Abstract: In a scan converter for converting polar-coordinate radar data into a standard video display scanned at a 100 ns per pixel rate, the reading of sixteen x-y pixels into the video buffer, writing of two polar pixels into the x-y memory, and fading of four x-y pixels in the x-y memory can all be accomplished in a single 1600 ns time slot by using a nibble mode of addressing with an x-y memory made up of four standard 64K chips operable in parallel. In another aspect of the invention, radar data can be written into the x-y memory of a scan converter at double that rate without affecting the read or fade capabilities by configuring the x-y memory chips in such a manner that a given address on the memory chips represents a group of adjacent pixels of one line of the display and a corresponding group of pixels of the next adjacent line of the display.

Abstract: The hematocrit of a volume of blood can be determined in real time without volume or flow rate limitations by sensing the diffusion of infrared light by the bloodstream. For this purpose, an infrared light beam is directed at a transparent cuvette through which the blood is conveyed, and a photodetector is mounted beside the cuvette at an angle such that the intersection of the light beam and of the principal sensitivity lobe of the detector is wholly spaced from the multiple scatter zone adjacent to the light source. The hematocrit signal produced by the photodetector can be corrected for the effect of oxygen saturation by providing an oxygen saturation signal, multiplying the hematocrit signal by a function of the oxygen saturation signal and using a look-up table to derive a linear true hematocrit signal. Means are also provided to compensate the detected hematocrit signal for the effects of temperature, drive current, and aging.

Abstract: An eyepiece assembly for an endoscope focusable by an exterior focusing collar is made soakable by using an O ring and very fine screwthreads to prevent liquid sterilant from penetrating under the collar and entering the interior of the eyepiece. The use of an O ring also provides a uniform resistance to the turning of the focusing collar and makes the focusing adjustment shock resistant. In another aspect of the invention, the placement of the light fiber connector on the discardable stop housing improves light transmission and allows one-handed focusing of the eyepiece.

Abstract: In a CRT display of digitized gray scale information from a diagnostic scan, an operator-selectable area of the display can be highlighted to increase the contrast and brightness of a selected portion of the image while simultaneously viewing a wide range of information levels in the background portion of the image. The highlighted area and the background may encompass different operator-selectable information level windows. To accommodate the wide dynamic range necessary for such a display, and eliminate possible contouring effects when enhancing dark areas of the image, more gray scale display levels are used than are commonly used with diagnostic scanning systems, and full black on the CRT is set to correspond to a minimum digital display level sufficiently high so that no single display step results in more than a maximum predetermined contrast ratio in the display.

Abstract: A vibratory massage device for use in conjunction with therapeutic exercises. The device has several belts of varying sizes, to which one or two vibrator units can be releasably attached for use on various body parts. An elastic band on each belt firmly presses the vibratory unit against the belt web when the belt is tightened, so as to prevent irritation-producing movement between the belt and the patient's skin. The motor of the vibratory unit is provided with a carrier bearing and eccentric-operated air flow means to permit miniaturization of the vibratory unit without loss of effectiveness.

Abstract: Filter quality is substantially improved (or complexity substantially reduced) in a digital PSK modem requiring an overall filter characteristic of the percent raised cosine type by using, in both the transmitter and the receiver, a filter having the same percent raised cosine response but at a higher cutoff frequency which satisfies the formula ##EQU1## where f.sub.f is the cutoff frequency (6 db) of the new filter, f.sub.o is one-half the baud rate of the modem, and .alpha. is the percent raised cosine expressed in decimal form.

Abstract: Error multiplication in the differential decoder and descrambler of V.22 bis modems is avoided by replacing the differential coding with forward error correction and single symbol coding. The error syndrome bit of the error corrector is used in establishing phase and timing synchronization by causing the receiver to try all possible combinations of phase and timing, and to lock onto the combination which produces a minimum of error syndrome bits. The descrambler receives the error-free corrected bit stream, whereby the descrambler's inherent error multiplication becomes moot.

Abstract: A nut for stringed instruments which allows unimpeded movement of the strings within the grooves of the nut for accurate and stable tuning. The nut includes grooves which are flared outwardly and downwardly in the direction of the body of the instrument beyond the support point of the string. The string is supported on rollers which are freely rotatable within the nut, and whose surface protrudes into the grooves to support the strings. The rollers may be circumferentially grooved to maintain the strings in lateral alignment on the nut, and in one embodiment of the invention, they may be of different diameters so as to maintain a constant spacing between each string and a cambered fingerboard.

Abstract: Thrombus formation in an implantable blood pump is prevented by using a close-tolerance purge seal for the impeller shaft or rotor. A blood-compatible fluid is used for the purge fluid (which is preferably also the bearing fluid), and the purge flow into the blood stream presents to the blood stream a benign interface between the rotating and stationary parts of the pump. The rotating and stationary surfaces adjacent the interface are so configured as to present an essentially continuous smooth surface across the interface which can be swept by the blood stream and presents no cavities in which the blood can stagnate. The close clearances of the purge seal allow a sufficient purge flow rate to be maintained with only a minute amount of purge fluid; and in accordance with one aspect of the invention, the purge fluid can be derived from the blood stream by a protein-filtering membrane system so that no external replenishment of the purge fluid supply is necessary.