Abstract: Inexpensive communication is provided between a data base and a plurality of subscribers each equipped with only a telephone and a TV set by using only tone signals to communicate from the subscribers to the data base, and data signals at least partially to communicate from the data base to the subscribers. For this purpose, each subscriber location needs to be provided with only the demodulator portion of a modem, and the base location needs to be provided only with the modulator portion of a modem and a tone decoder. A microprocessor-controlled security device is disclosed for remotely disabling a subscriber's module in case of misuse.

Abstract: Adjustment of the field-of-view angle in a surgical microtelescope from the outside of the patient's body is made possible by including in the objective optical system an assembly of mutually movable prisms. The prisms can be moved by a wire running alongside the optical fibers which convey illumination through the tube. In one embodiment, a movable prism pivots with respect to a fixed prism about an axis coincident with the axis of the image as it is transmitted between the prisms; in another embodiment, a partially silvered prism is slidable between two fixed prisms so as to pick up the image from one of them in one position, and the image from the other in the other position. Apparatus in the eyepiece is also disclosed to compensate for the rotation of the image when the pivoting embodiment is used.

Abstract: A device in which to place an article to be retrieved later by an intended recipient employs a container having a forward portion defining a first opening through which to insert an article, a rearward portion defining a second opening through which to retrieve the article, and a size and shape enabling the container to be mounted on a conventional door. The device includes a lockable cover member for limiting access through the first opening, and a bracket for supporting the container adjacent the door by closing the door with the bracket between the door and door frame. The bracket is attached to the container to support the container in a position enabling cover removal for access through the first opening while retaining the rearward portion closely adjacent the door to inhibit access through the second opening.

Abstract: A safety system for battery-operated, microprocessor-controlled infusion pumps using separate primary and reserve batteries. When the primary battery nears exhaustion, the reserve battery is switched in and an interval timer is started, but the pump operation is not interfered with. At the expiration of the timer interval, the pump is switched to a KVO mode to keep it in minimal operation as long as possible. When the reserve battery also nears exhaustion, the microprocessor is signalled to perform an orderly shutdown routine while battery power is still available. Audible alarms may be provided to apprise nursing personnel of the various phases in the system's operation.

Abstract: A high-quality, real-time text-to-speech synthesizer system handles an unlimited vocabulary with a minimum of hardware by using a microcomputer-software-compatible time domain methodology which requires a minimum of memory and computational power. The system first compares test words to an exception dictionary. If the word is not found therein, the system applies standard pronunciation rules to the text word. In either instance, the text word is converted to a phoneme sequence. By the use of look-up tables addressed by pointers contained in a phoneme-and-transition matrix, the synthesizer translates the sequence of phonemes and transitions therebetween into sequences of small speech segments capable of being expressed in terms of repetitions of variable-length portions of short digitally stored waveforms.

Abstract: A vibrato device for guitars which is easily omnidirectionally adjustable by a clamp screw and a pivot screw concentric therewith, both conveniently accessible from the rear of the device, and by elevation screws mounted in the string-supporting saddles and conveniently accessible from the top of the device. The brass saddles are provided with a steel block insert for improved resonance and damping, and the control lever can be conveniently either locked in one position, or allowed to swing freely, at any time during play. The device is provided with self-centering straight knife-edge bridge pivots. The free ends of the strings are clamped to the bottom of a steel sustain block depending from the bridge of the device, and the clamp screws for both the strings and the lateral saddle position adjustment are turnable with coins.

Abstract: Malfunctions in an automatic span line switch due to resonances in high-speed span lines are avoided by interposing signal-free intervals whenever the switch causes a possible phase change to occur in the signal being supplied to the span, preventing the transmission of partial signal pulses, and using quasi-random code and keep-alive signals. Unnecessary phase changes are avoided by verifying the validity of data before allowing it to be put on the span following a data loss; disabling the error detection circuitry for a limited time following a switching operation; and preventing the switching of low-priority span on standby if the failure has been remedied during the standby period.

Abstract: Accurate in vivo measurement of blood oxygen saturation by fiberoptical means is made possible throughout a wide range of hematocrit or total hemoglobin values by using a single R/IR ratio I and calculating the SO.sub.2 value therefrom through the use of a second-order polynomial of the formSO.sub.2 =Ak.sup.2 I.sup.2 +BkI+Cin which A, B and C are hematocrit or total hemoglobin-dependent coefficients. These values may be contained in a lookup table accessed by a hematocrit or total hemoglobin value selection, and k is a purely multiplicative calibration constant which can be readily determined for any individual fiberoptic system.

Abstract: Previously undesired artifacts in a color signal used in fiberoptic cardiac catheters to measure blood oxygenation levels are used to produce indications of blood flow and true pulse. For this purpose, the color signal is band-pass filtered to derive a DC mean signal level .mu. and an AC signal containing only those frequencies at which the signal is affected by blood flow variations. The RMS value of that band-pass-filtered AC signal (which corresponds to the standard deviation .sigma. of the AC signal) is divided by the DC value .mu. to produce a .sigma./.mu. signal representative of flood flow. By clipping the AC signal and using the resulting square wave to drive a one-shot multivibrator, an indication of the patient's true pulse can be obtained.

Abstract: Stress cracking of polycarbonate parts during prolonged storage while assembled with plasticized polyvinyl tubing is greatly reduced by using tubing in which tri-2-ethylhexyl trimellitate is the predominant or sole primary plasticizer.

Abstract: An opposing vortex oscillator is used to control the frequency and duty cycle of a high-frequency jet ventilator for trauma management in acute and uncontrolled situations where no power other than the pressure of the ventilation gas itself is available. Frequency adjustment is achieved by connecting variable volumes to one inlet of the oscillator while duty cycle control is achieved by supplying fluid to one inlet of the oscillator through a variable-orifice bias control valve. Safety means are provided to automatically disable the ventilator in case of airway blockage.

Abstract: A removable cover for converting a programmable infusion pump into a patient-controlled analgesia (PCA) device. The cover can be placed onto an infusion pump and electrically connected thereto when open. The cover includes an internal switch which allows selection of normal or PCA pump operation. A second internal switch automatically disables the keyboard of the pump when the cover is closed. The cover is lockable, and when it is closed and locked, the internal switches are inaccessible, the cover cannot be removed from the pump, and the electrical connection to the pump cannot be disconnected. When closed, the cover also defines an inaccessible compartment for the storage of medication. An external push button is provided to allow the patient to trigger analgesia doses at safe intervals when the pump is in the PCA mode.

Abstract: Full-flow cardiac assist is provided for cardiogenic shock patients without major surgery by a miniature axial-flow pump which can be inserted into the heart through the femoral artery and driven via a flexible cable from an external power source. The cable is contained within the catheter attached to the pump. The catheter also provides a conduit to supply the pump bearings with a blood-compatible purge fluid at a rate and pressure sufficient to prevent thrombus formation and introduction of blood elements between rotating and stationary elements of the pump. Due to the very small diameter of the pump, rotational speeds on the order of 10,000 to 20,000 rpm can be used to produce a blood flow on the order of about four liters per minute without significant hemolysis.

Abstract: The memory needed for the digital storage of a waveform having an amplitude range of .+-.128 units is compacted by nearly 50% through the use of a 16-position table containing selected increments. Each waveform sample value is first predicted from at least two prior samples by linear prediction, and the predicted value is then incremented by the most nearly accurate increment in the table to obtain an approximation of the actual waveform value at the sample point. The appropriate increment for each sample can be defined by a 4-bit table address. The best-fit increment values for any given waveform can be calculated by a reiterative trial-and-error computation process. By the use of a best-fit table, inaccuracies in the waveform reproduction can be held below audible levels.

Abstract: A small, simple, yet accurate probe for producing a sector scan for ultrasonic medical diagnostic apparatus is provided by positioning a curved transducer array within the probe opposite a window, and filling the probe with a fluid having an acoustic velocity on the order of 0.5.times.10.sup.5 cm/sec. This combination is made possible by forming the window from a stiff polyionomer material whose acoustic velocity is closed to that of human skin, yet which is stiff enough even when thin to be essentially non-deformable in clinical use. Grating lobes of the ultrasonic beam, as well as the scatter produced within the probe by the high reflectivity of the window material, are absorbed by coating or lining the inner side walls of the probe with an open-celled polyether urethane foam having a cell diameter slightly smaller than one wavelength of the ultrasound in the probe fluid.

Abstract: Calibration testing of a blood pressure transducer can be performed in immediate proximity to the body of the patient by including in either the transducer housing or the housing of a connector located adjacent thereto, a pair of membrane switches on opposite sides of the housing. The switches are connected in series with each other and with a shunting resistor which, when connected across one input and one output port of the transducer's circuit, will produce a predetermined pressure reading. The switches are so arranged as to require simultaneous actuation from two sides of the housing to prevent accidental actuation of the testing circuit by the patient.

Abstract: A slit lamp with surgical laser capability includes an x-y table. An optical micrometer, readily retrofittable onto existing slit lamps, is mounted on the x-y table to measure table displacement in the y direction. The measuring electronics are resettable to allow the operator to select any y position from which the displacement is to be algebraically measured. Compact display optics are retrofittably mounted on the ocular assembly of the slit lamp between the collimator and the eyepiece to insert a reduced image of an LED indicator displaying the measured data into the periphery of the ophthalmic image seen through the eyepiece. An LCD indicator displaying the same data is mounted on the x-y table to allow positioning of the table without looking into the eyepiece. The LED indicator lends itself to display of laser operational data in addition to positional data.

Abstract: In devices such as electronic calculators, which perform mathematical or like functions and require plurality of data inputs to perform their functions; a data input key is pivotally maintained within the body of said device and is adapted to provide a plurality of input data. The data input key has an upper exposed portion having an opening configured and adapted to be engaged by the thumb or finger of the user whereby the key may be manipulated to various contact positions situated in a circular or longitudinal path. These various contact positions provide different input data to the device. In another embodiment, a plurality of the input keys may be used to accommodate a large number of inputs, for example, the inputs of a typewriter.

Abstract: A disposable strain gauge pressure sensor providing reliable electrical isolation even at defibrillation voltages in the measurement of biological fluid pressures is produced by floatingly mounting a glass plate on a closed cell, fluid-impervious foam pad within a firm but not totally rigid plastic housing. The glass plate has a thin glass diaphragm integrally formed therein which carries the strain gauge element. Openings in the foam pad and the housing allow a fluid contained in a fluid dome on the outside of the housing to bathe the side of the glass diaphragm opposite that on which the strain gauge element is mounted. The glass plate, foam pad, and housing are bonded together in fluid-tight relationship so that fluid cannot reach anything within the housing other than the glass diaphragm. The housing is preferably transparent to allow observation of the diaphragm during operation.