Abstract: A hand-held electronic pipettor is designed particularly to be programmed and operated with one hand for the convenience of the user. It uses a capacitance touchpad control for programming, and a separate run button for the operating mode. Internal components are located so that the center of gravity of the pipettor is located within the palm of the user. Flash memory stores an empirically derived table that correlates aspiration volume to motor steps and a separate empirically derived table the correlates dispensing volumes to motor steps.

Abstract: A hand-held electronic pipettor is designed particularly to be programmed and operated with one hand for the convenience of the user. It uses a capacitance touchpad control for programming, and a separate run button for the operating mode. Internal components are located so that the center of gravity of the pipettor is located within the palm of the user. Flash memory stores an empirically derived table that correlates aspiration volume to motor steps and a separate empirically derived table the correlates dispensing volumes to motor steps.

Abstract: A hand-held electronic pipettor is designed particularly to be programmed and operated with one hand for the convenience of the user. It uses a capacitance touchpad control for programming, and a separate run button for the operating mode. Internal components are located so that the center of gravity of the pipettor is located within the palm of the user. Flash memory stores an empirically derived table that correlates aspiration volume to motor steps and a separate empirically derived table the correlates dispensing volumes to motor steps.

Abstract: A hand-held electronic pipettor is designed particularly to be programmed and operated with one hand for the convenience of the user. It uses a capacitance touchpad control for programming, and a separate run button for the operating mode. Internal components are located so that the center of gravity of the pipettor is located within the palm of the user. Flash memory stores an empirically derived table that correlates aspiration volume to motor steps and a separate empirically derived table the correlates dispensing volumes to motor steps.

Abstract: A pipetting system having a plurality of tip fittings whose spacing can be simultaneously, quickly, and accurately adjusted so that the spacing between each adjacent tip fitting is substantially identical. The tip fittings are attached one to another by a linkage such as a pantographic linkage. The spacing is limited by an adjustable, slidable stop. Uniformly increasing and decreasing the spacing is accomplished by pulling and pushing a rod attached to one tip fitting.

Abstract: A pipettor including a body portion, a cylinder having an interior channel, and a filter plug disposed within the channel is disclosed. The filter plug may include a plurality of pores and may preferably be treated with a first chemical, so as to affect closure of the pores when the filter plug contacts a pipetted fluid. The pore closure helps contain leakage of the fluid into the pipettor by sealing the pipettor to additional fluid flow. The filter plug may also be treated with a second chemical to affect a change in the color of the filter plug upon contact with the pipetted fluid. The color change acts as a signal to an operator that possible contamination of the pipettor has occured. The color change and/or closure may also be affected by an aerosol generated from the pipetted fluid.

Abstract: An improved pipette tip support rack having a honeycomb structure. The rack includes an array of interconnected sleeves, each of the sleeves being constructed to support a pipette tip therein. The sleeves are connected by bridges which form along abutting, touching surfaces thereof, or which extend between non-touching sleeves. Openings are formed between adjacent ones of said sleeve which occupy substantially all of the space between adjacent sleeves not occupied by the bridges. Inwardly extending lips on the interior of each sleeve support the enlarged portion of the pipette tip and provide a channel through which the stem extends. Interior side walls of each sleeve provide lateral support to the pipette tips. The tray may be used in conjunction with a container to provide ventilation during autoclaving. The tray snaps into the container and rests on shoulders therein. A finger tab is provided for lifting the tray out of the container.

Abstract: An implantable medical device uses a solid-state sensor for detecting the application of an external magnetic field. The sensor includes first and second split-drain field-effect transistors (MAGFETs) which are cross-coupled such that an external magnetic field perpendicular to the channel regions of the MAGFETs causes an increase in current through one split-drain half of each MAGFET, and a decrease in current through the other split-drain half of each MAGFET. The sensor also includes a high-gain differential amplifier coupled between the MAGFETs for detecting changes in the current conducted through the respective split-drain halves, and produces an output voltage which changes upon application of an external magnetic field to the implantable medical device. The magnetic sensor operates at low power supply voltages and bias currents available in implantable medical devices such as a cardiac pacemaker, so that current drain and power consumption are minimized.

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 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 battery powered cardioverter or defibrillator employing output capacitors for delivery of cardioversion or defibrillation pulses. The capacitors are charged by means of a step-up transformer, coupled and uncoupled from the battery by means of a voltage controlled oscillator which varies its off and on times as a function of the voltage on the battery and the voltage stored on the output capacitor to allow for rapid charging of the capacitor even under conditions of battery depletion. The voltage controlled oscillator is constructed to provide a highly accurate timing signal with a low current drain.

Abstract: A pipetting system having a plurality of fittings whose spacing can be simultaneously expanded from one dimension to another. Increasing the spacing is accomplished by pulling a rod, attached to one fitting, which elongates the series of fittings to a second position. In addition, there is a release mechanism for removing disposable tips attached to the fittings. The release mechanism can be operated in either position of the fittings. The mechanism is trigger actuated.

Abstract: A pipetting system having a plurality of fittings whose spacing can be individually adjusted by sliding the fittings along a track. Changing the spacing is accomplished by releasing a clamping plate which secures the fittings to the track. The fittings are then slid into the desired position and reclamped. In addition, there is a stripper mechanism for removing disposable tips attached to the fittings. The release mechanism can be operated in any positioning of the fittings. The mechanism is trigger actuated.

Abstract: A computer controlled pipetting system with a hand held pipettor and a control assembly. The pipettor has a motor driven pump for aspirating and dispensing liquid through a pipette which is inserted to the pipettor. The control assembly has a keyboard for controlling operation of the pipetting system. A calibration pipette is inserted into the pipettor for establishing reference signals corresponding to a selected density and temperature of a liquid which is aspirated into the calibration pipette by the pump. The reference signals are stored in a memory and subsequently used for aspirating selected quantities of liquid into a laboratory pipette which is inserted into the pipettor in place of the calibration pipette.

Abstract: Herein presented is a device for shutting off the flow through a pipe. The device is basically a pincers tool with two jaws and two handles. It, however, has special and unique features that make it rugged, reliable, efficient and easy to use.It has compound leveraging. It has pivotal features that allow the inner surfaces of its jaws to remain parallel to one another as the jaws are opened and closed. A latching and releasing mechanism permits the locking of the handles once the jaws have reached a desired closed position.

Abstract: A pacemaker sense amplifier circuit exhibiting a very high common mode rejection ratio for detecting intracardiac electrogram signals is disclosed. The circuit includes a sampling capacitor which is differentially charged by the intracardiac signal. The voltage stored on the sampling capacitor is periodically applied to a high input impedance differential voltage amplifier which is referenced to the battery ground. The signal is smoothed and reconstructed by a bandpass filter, and is applied to a comparator to generate a logic level pulse indicative of the occurrence of a cardiac depolarization.