摘要:
A sample cell for use in spectroscopy includes two cell portions that are mutually adjustable to enable a user to vary the cross sectional geometry of sample cell flow path thereof between at least two discrete configurations or positions. In a first position, the flow path may be provided with a relatively small cross-sectional area to provide a relatively small pathlength and generate high velocity fluid flow therethrough. The small pathlength enables use of relatively small sample volumes and facilitates optical measurement of samples, such as blood, which have relatively high optical density, absorbance or light scattering properties. In a second position, the flow path provides a larger cross-section adapted to permit larger agglomerations or clots to pass through the flow path to facilitate cleaning of the sample cell. The cell portions are maintained in slidable engagement with one another so that the adjustability of the flow path is accomplished by sliding movement of the cell portions relative to one another. In one embodiment, the cell portions are engaged along generally planar mating surfaces and the adjustability is accomplished by sliding the mating surfaces relative to one another. In another embodiment, the mating surfaces are superposed in spaced relation to one another, and the adjustability is accomplished by varying the distance therebetween.
摘要:
A novel fluid sampling device has been developed. This device provides for sample entry to be handled automatically by the instrument, thus allowing the operator to be involved in other activities while the sampling process is underway. It also assures reproduceable sample size, automatically cleans the sampling device between samples, and reduces the risk of user injury. Furthermore, the sampling system allows for the use of any forseeable collection mechanism.
摘要:
A novel fluid sampling device has been developed. This device provides for sample entry to be handled automatically by the instrument, thus allowing the operator to be involved in other activities while the sampling process is underway. It also assures reproduceable sample size, automatically cleans the sampling device between samples, and reduces the risk of user injury. Furthermore, the sampling system allows for the use of any forseeable collection mechanism.
摘要:
A capnography system has a 4.2 micron LED emitter of narrow-band radiation having a center wavelength very close to the 4.26 micron absorption band of CO.sub.2 breathing gas in a breathing tube. The radiation passes through windows in an insert in the breathing passage between the LED source and an infrared detector in an opposite side of the insert. A mirror is optionally placed in the opposite wall to reflect the radiation back to the detector which is then placed on the same side as the emitter. The LED emitter is pulsed at a low frequency repetition rate with a regulated voltage from a power supply. The detector output is applied to processing electronics which includes amplification and dual integrators that integrate the detector output on two signal paths, one the integration of each pulse and the other the integration of detector background with the two differences to provide self calibration against drift and noise. A heater heats the emitter, infrared detector, local electronics and the windows thereby stabilizing these temperature sensitive components to minimize the measured CO.sub.2 value error to a few mm of mercury and to prevent condensation on the insert particularly in the windows. A second emitter is optionally used as a reference and/or to detect additional gas concentrations.
摘要:
An electrochemical/gas analyzer providing a rugged contact system for removable sensors capable of withstanding inexpert sensor insertion or removal, providing protection for high impedance input electronics against electrostatic discharge (ESD) damage, and providing automatic connection to diagnostic circuitry upon sensor removal has been developed. The contact system includes a plurality of stamped contacts electrically connecting a diagnostic circuit, including a source of diagnostic signals and a ground path, to analyzer signal processing circuitry. Removal of a sensor from this system electrically connects the sensor signal processing electronics to the diagnostic circuit. Insertion of the sensor interrupts electrical connection between the diagnostic circuit and the stamped contact, which connects the sensor terminals to the signal processing circuitry.
摘要:
Methods and apparatus wherein a very small number of sorted cells are attached to specified locations on a microscope slide circumscribed by well areas of a retainer slip. The cells are deposited in the wells and during centrifugation of the slide-retainer sandwich, are contacted with and attached to the serum albumin present in the well and coated on the slide. Removal of excess fluids, optional clamping means and the retainer slip followed by air drying provides for permanent attachment of rare, sorted cells in a localized, known area for subsequent staining, examination and analysis.
摘要:
A novel method and system are disclosed for detecting the breakpoint of a perturbed flow stream. The scattering and extinction of light caused by a perturbed stream at a preselected flow stream sensing point therealong is measured to produce a real time waveform proportional thereto. The real time waveform is differentiated to produce a differentiated waveform, which is then selectively monitored to distinguish a waveform exhibiting substantially three (positive and negative) peaks per cycle, whereby such detection indicates that at least a portion of the breakpoint region of said flow stream corresponds with said flow stream sensing point. In order to align the stream sensing point with respect to a preselected point within the breakpoint region of the flow stream, the breakpoint region of the stream is caused to move with respect to the stream sensing point until the breakpoint pulse width of one of the peaks corresponds with a preselected pulse width reference.