Abstract: A grinding apparatus optimizes grinding efficiency within the grinding chamber by providing grinding action over a 360.degree. range encompassed by a set of breaker bars and one or more arcuate screening elements. Arcuate screening elements have an inside radius that identically matches the inside radius of the breaker bars. The screening elements act as grinding mechanisms as well as more conventional filtering mechanisms due to increased grinding capacity when the inside radial surface of the screening elements and the inside radial surface defined by the breaker bars are equidistant from the axis of a rotational shaft that supports a plurality of circumferentially spaced hammers.

Abstract: A maintenance free, easy to install portable dock system has a rotational molded shell constructed of a UV resistant, linear low density polyethylene. The dock shell includes a plurality of internal columnar truss supports strategically located to provide structural integrity. An "L" or "T" pier type or floating type dock can be formulated simply by coupling a desired number of dock shells together in a desired configuration via a full width self-aligning latching structure which does not require the hand and eye coordination generally required for known dock structures. The dock shell has support beams which run longitudinally over the entire length of the dock shell. Metal stringers are inserted into the outer most support beams to further enhance the structural integrity and increase the rigidity of the dock shell. Buoyancy for the dock shell is ensured with a polyurethane foam which is injected into the dock shell.

Abstract: A Condition Sensing Hydromechanical Fuze to sense hydraulic line flow for velocity, volume, direction and flow measurement. The fuze is self adjusting with temperature changes and safely enables hydraulic circuit segregation and cross porting to maintain normal operation of a primary hydraulic circuit following degradation or failure of a secondary hydraulic circuit in a dual input manual vehicle brake system or other nonbrake system application which requires the ability to segregate one portion of the system from another based on regulated flow volume and rate.

Abstract: An apparatus which reduces arm, wrist and shoulder stress and pain while using a computer mouse device. This apparatus includes an adjustable working surface which is capable of aligning the angle inclination as well as the angle of rotation of a mouse device user's hand, wrist and forearm with respect to the stationary working surface of the structure on which the apparatus is resting while operating the mouse device. The apparatus is adaptable to fit any adult size and is capable of use with either the left or right hand.

Abstract: An ornamental hair barrette provides a mechanism allowing for rapid replacement, removal or addition of alternate ornamental appendages without requiring the wearer to remove the barrette from the wearer's hair each time the ornamental appendages are replaced, removed or supplemented. The mechanism includes ribs and recesses for interlocking a stem to a shaft having at least one slot extending substantially lengthwise along the stem or the shaft which allows the interlocking to take place via spring-like expansion and retraction of the stem or shaft respectively.

Abstract: A monitoring system for an oxygen sensing, dual-wavelength, reflectance oximetry based, rate responsive cardiac pacemaker, is capable of automatically and continually adjusting an oxygen sensor signal comparator threshold such that the effects of noise, sensitivity and drift on oximeter output signals sent to the pacemaker are minimized. A comparator and related circuitry are configured to sample and compare supply excitations for multiple oxygen sensor light sources. The comparator threshold is adjusted as a function of supply excitation for each light source independently of one another, thereby providing an oxygen sensing pacemaker with optimal noise immunity since one of the more vulnerable portions of the pacing system is the transfer of the light source signals which are susceptible to noise.

Abstract: A low cost, limited-function implantable medical device. The device's synchronous circuits are driven by an ultra-slow master clock signal produced without utilization of a crystal oscillator. The device is non-invasively programmable by means of an externally applied programming magnet, which is detected by a solid state magnetic sensor (MAGFET) circuit in the implanted device. The MAGFET circuit is capable of discriminating between two polarity orientations of the programming magnet, so that one polarity is associated with increasing programmable parameters and the opposite polarity is associated with decreasing programmable parameters. Upon initial placement and detection of the programming magnet, the disclosed device performs a threshold margin test comprising three asynchronous stimulating pulses at the current pulse width and pulse amplitude settings.

Abstract: A rate responsive cardiac pacemaker for providing an optimized pacing rate of stimulation pulses as a function of at least one selected rate control parameter. Each rate control parameter has a value which varies as a function of changes in a patient's physiologic demand and includes a sensor system for sensing the rate control parameter value and for providing a sensor output representative thereof.

Abstract: A rate-responsive cardiac pacemaker comprising a minute ventilation circuit and an activity circuit. The minute ventilation circuit computes a first target pacing rate as a function of measurements of the patient's pleural blood impedance, and the activity circuit computes a second target pacing rate as a function of measured levels of patient activity. A rate control function establishes a rate-responsive pacing rate based on the first and second target pacing rates. The minute ventilation circuit delta-modulates an analog impedance waveform and maintains short-term and long-term weighted averages of delta-modulator output counts. Variations in the difference between the short-term and long-term weighted average values are determinative of the first target pacing rate. Variations in an activity sensor output signal are determinative of the second target pacing rate.

Abstract: An apparatus for communicating an electrical signal from a first portion of circuitry to a second, wherein there is no direct electrical contact between the two portions. In one embodiment, an EKG transmitter is disclosed which receives surface EKG signals from a patient, amplifies the EKG signals, modulates an oscillating carrier signal with the EKG signals, and transmits the resulting modulated signal across an optocoupled boundary. The modulated signal is then digitized directly, without demodulation, using phase progression digitization. The digitized information, from which the patient's EKG signal may be reconstructed, is then transmitted via a modem over conventional telephone lines. DC power drawn from the telephone line may be used directly to power the modem and phase progression digitizer, and may also be coupled via an isolating DC-to-DC transformer, to the frequency modulator and amplifier.

Abstract: A cardiac pacemaker of the type including a sensor responsive to the patient's metabolic demand for oxygenated blood and which varies the pacing rate in response to the output of the sensor. In the disclosed embodiment, a piezoelectric sensor bonded to the inside surface of the pacemaker's outer shield delivers a pulsatile sensor signal to activity circuitry, where the different peak values of the pulsatile signal correspond to different levels of patient activity. The activity circuit defines a plurality of sensor signal threshold levels. Rate control circuitry increases the pacing rate of the pacemaker by amounts corresponding to the threshold level exceeded by recent peak values of said pulsatile signal; peaks of said pulsatile signal which exceed only the lowest of the thresholds cause the smallest increase in the pacing rate, while sensor signals which exceed higher thresholds cause larger increases in the pacing rate.

Abstract: A pacemaker capable of automatically adjusting the activity threshold setting of its activity sensor signal processing circuitry to its optimal value is disclosed. In one embodiment, the pacemaker maintains a running average of zero activity time and a cumulative summation of zero activity time over a predetermined history period. Periodically, the pacemaker computes a time difference between the running average of zero activity time and the cumulative summation of zero activity time, and adjusts the activity threshold of the activity sensor signal processing circuitry according to this computation. By basing the adjustment of activity threshold on a long-term average of zero activity time, the effects of cycle-to-cycle variation in sensed zero activity time are minimized. In another embodiment, the pacemaker periodically computes a time difference between a preprogrammed margin value and the cumulative summation of zero activity time.

Abstract: A post-extrasystolic potentiation (PESP) cardiac pacing energy stimulator for applying paired and/or triggered pacing stimulation pulses to the right atrium and/or ventricle incorporating one or more sensors, such as a venous oxygen saturation, ventricular, atrial, or arterial blood pressure, or intracardiac or systemic blood flow sensor, and signal processing circuitry for controlling the frequency of or number of heart cycles between periodic delivery of triggered or paired pacing to induce PESP for the treatment of congestive heart failure or other cardiac dysfunctions. Preferably, a first sensor, e.g., a ventricular or arterial blood pressure or flow sensor, is employed to monitor the performance of the heart, and develop a cardiac performance index (CPI) and a second sensor, e.g., an oxygen saturation sensor positioned in the coronary sinus, is employed to monitor cardiac muscle stress and develop a cardiac stress index (CSI) to balance performance and stress.