Abstract:
A system for plotting the total luminescence spectrum of a sample comprises a spectrofluorometer including excitation and emission monochromator stages having operating wavelengths dependent on applied stepping pulses, and an X-Y plotter having a marking pen synchronized for movement along X and Y axis with changes in the wavelengths of the monochromators. A control circuit generates pulses to incrementally step the emission monochromator and horizontally scan the marking pen. A level detection circuit monitors the output of the spectroflourometer and activates the pen upon attainment of a desired contour level. Limit circuitry incorporated in the control circuit momentarily actuates the excitation monochromator following each horizontal scan to increase the excitation wavelength for the subsequent emission scan to complete the plot.
Abstract:
Cuvette positioning apparatus for use in a spectrophotometer adapted for comparing first and second material samples includes a carrier in which cuvettes to be alternately analyzed are arranged end-to-end. The carrier is reciprocated along a vertical axis to expose the cuvettes in alternation to the monochromatic beam of the apparatus. The rate of reciprocation is selected to avoid cavitation of the samples, and a sinusoidal drive arrangement increases the exposure time of the samples to the light beam and minimizes transit time for optimum measurement efficiency. Circuitry responsive to synchronizing signals derived from the drive arrangement is utilized to form an output signal indicative of the difference in measured characteristics between the samples.
Abstract:
The present invention relates to a blood analyte measurement system for the procurement of blood samples for measurement of blood properties such as analyte concentration or analyte presence. A blood access system can be coupled with a measurement system such as an electrochemical sensor, and can also be used with other measurement modalities. Embodiments of the present invention can facilitate accurate measurement of blood glucose by the clinician in a sterile manner. Embodiments of the present invention can also enable the calibration of the sensor at one or more calibration points. One desired analyte of measurement is glucose for the effective implementation of glycemic control protocols. Embodiments of the present invention can also be used for the measurement of other analytes such as arterial blood gases, lactate, hemoglobin, potassium and urea. Additionally, embodiments of the present invention can function effectively on a variety of blood access points and specifically enables glucose monitoring in an existing arterial line that is already in place for hemodynamic monitoring. The present invention does not consume a significant amount of blood. Some embodiments of the present invention can re-infuse the blood into the patient, which can facilitate operation of the system in a sterile manner.
Abstract:
A method for removing bubbles adhering to the interior wall of a fluid-filled chamber through which a fluid flows, and a related method and apparatus for removing bubbles from a chamber having medical sensory equipment such as a blood gas and chemistry analyzer. The method includes drawing a quantity of gas into the chamber to empty the chamber of fluid, maintaining the chamber in an empty state for a predetermined period of time, and then refilling the chamber with fluid at a rate low enough to remove remaining bubbles and to prevent the formation and trapping of new bubbles within the chamber.
Abstract:
A spectrofluorometer providing wavelength correction by means of an arbitrary function generator driven by a wavelength scanning element of the spectrofluorometer. The arbitrary function generator may be driven by the emission scanning monochromator to derive a wavelength-dependent voltage signal which is combined with the measure photomultiplier output to thereby provide a base-line compensated resultant output signal. Alternatively, the arbitrary function generator may be driven by the excitation scanning monochromator to derive a wavelength-dependent voltage signal which is combined with the output of a reference photomultiplier tube receiving part of the output of the excitation monochromator to derive an excitation-corrected reference signal which is in turn combined with the measure photomultiplier tube output signal to thereby provide an energy-corrected resultant output signal. An analog divider may be employed to divide this last-named resultant output signal by said excitation wavelength-dependent voltage signal to thereby derive a quantum-corrected fluorescence emission output signal. The arbitrary function generator has successive incremental wavelength range segments provided respectively with independently adjustable potentiometers to suitably shape the wavelength-dependent voltage signal curve.
Abstract:
A mixing device includes a plurality of elongated ampules mounted on a rotatable support with the longitudinal axis of each ampule inclined inwardly toward the rotational axis of the rotatable support. When the mixing device rotates about the rotational support, centrifugal force causes fluid in each ampule to move toward the end farthest away from the rotatable support. A bubble in each ampule then moves toward the opposite end. In one embodiment, the rotational support is inclined so that the end of each ampule positioned farthest from the rotational support is positioned sufficiently above the other end so that the bubble rises to the end farther from the support in at least one position as the support rotates. As a result, a bubble in each ampule moves back and forth between the ends of the ampule as the rotatable support rotates to mix respective fluids in the ampules. In another embodiment, the ampules are pivotably mounted on the elongated support so that opposite ends are alternately positioned farthest from the support, thereby causing a bubble to move back and forth in each ampule. A chamber for collecting a blood sampling may be positioned on the rotatable support for subsequent analysis by an analysis machine that uses the fluids in the ampules for calibrating and washing purposes.
Abstract:
A disposable sampling cartridge for use with a blood sample analyzer. The cartridge includes a blood reservoir communicating with a hypodermic needle, a waste collection chamber adapted to receive waste fluids from the blood sample analyzer, and a plurality of ampules each containing a respective analyzing fluid adapted for use by the blood sample analyzer. Each of the ampules contain a piston, and the analyzing fluids in the ampules are expelled by forcing an actuating rod through a frangible wall of the ampule to displace the piston. In one embodiment, the analyzing fluids are withdrawn through a conduit in the actuating rod while the blood and spent analyzing fluids flow through the blood reservoir port on which the hypodermic needle is mounted. In another embodiment the waste fluid flows through an inlet port while the analyzing fluids from the ampules flow through a common port outlet port which selectively communicates with the blood reservoir and the ampules by a valve arrangement.
Abstract:
The input polarizer and the output polarizer of a spectrofluorometer are each mechanically identical except for the optical elements, and are constructed as modules which plug into a spectrofluorometer base. Each of the polarizer modules includes a polarizing filter that is rotatable and a self-contained motor drive for rotating the polarizing filter. Each of the motor drives comprises an electric motor mounted on the respective module, a pulley mounted on the respective module and rotatable with actuation of the electric motor, a loop coupling the pulley to the polarizing filter for rotation of the filter with rotation of the pulley, and means for enabling the filter to rotate exactly 90.degree. in opposite directions.
Abstract:
A rotary sample changer for a spectrofluorometer has a revolving turret base which can be indexed and which carries an interchangeable sample carrier. Different sample carriers accommodate test cells, test tubes and cuvettes of different sizes and shapes.The revolving turret base and the interchangeable rotary sample carriers are constructed of material having good thermal conductivity and rotate on a large stationary hollow axle which is thermostated by thermally controlled internal fluid circulation to act as a heat source or sink to the samples. Thus, the sample carriers can readily be interchanged without disturbing the plumbing by which the thermostatic fluid is circulated.The revolving turret base is detented at the stations to which it is indexed without kinematic ambiguity and without application of any cocking force. Two spring biased ball detents, symmetrically spaced 180.degree. about the axis of rotation, are provided. At the four index stations one ball catches on one of two indexing grooves spaced 90.degree. apart, while the other ball bears against a flat.