摘要:
A method and apparatus for correcting a particle pulse count subject to coincidence error is disclosed wherein particle pulses, developed in response to passage of particles in a particulate system through a sensing zone, are counted for a predetermined period of time. The predetermined period of time is increased or extended in response to each pulse counted by a time increment that is related to a characteristic of the counted pulse, such as the pulse width, duration, or amplitude. The total additional time period allows the counting of additional particle pulses such that the total count at the end of the extended time period is an error corrected count for the number of particles detected in the predetermined time period.
摘要:
A method and apparatus for correcting a particle pulse count subject to coincidence error is disclosed wherein particle pulses, developed in response to passage of particles in a particulate system through a sensing zone, are counted for a predetermined period of time. The predetermined period of time is increased or extended in response to each pulse counted by a time increment that is a function of a characteristic of the counted pulse, such as the pulse width, duration, or amplitude. The total additional time period allows the counting of additional particle pulses such that the total count at the end of the extended time period is an error corrected count for the number of particles detected in the predetermined time period.
摘要:
A particle analyzer of the Coulter type has at least first and second sensing zone arrangements, each having substantially the same dimensions and each generating a train of particle pulses in response to passage through the respective sensing zone of a sample containing a plurality of particles to be counted. A summing circuit connected to the output of each sensing zone sums together each of the trains of particle pulses to develop a summed train of pulses. Additional circuitry is connected to each sensing zone and the summing circuitry. This circuitry is operative to change mathematically at least the number of particle pulses in the summed train of particle pulses. The mathematically changed summed train of pulses and the train of pulses from the first and second sensing zones then are accumulated to produce an error corrected particle pulse count.
摘要:
An apparatus which includes circuitry for automatically sampling each pulse in a series of pulses a predetermined average number of times, sequentially storing the samples for a period of time, and reproducing the pulses from the samples, delayed in time.A method of operation is encompassed within the invention as well as use of the above apparatus in a particle study device.
摘要:
An apparatus for determining the correct particle sizes at predetermined percentiles of the size distribution of a particulate system having a known size distribution characteristic such as for example a normal or log-normal size distribution, wherein a portion of the particles are too small to be measured. The particulate system is first passed through a particle detecting device which can be of the Coulter type. The particle detecting device produces particle pulses proportional to the size of the particles in the particulate system which can be measured. At least three percentile size determining circuits receive the particle pulses and develop first, second and third particle size signals respectively, indicating the size of the particles in the particulate system at the first, second and third predetermined percentiles. Two of the size signals are combined in a particular manner based on the known size distribution characteristic for the type of particulate system to yield a combined signal which approximates or is and estimate of the third percentile signal. The combined signal is compared with the measured third signal to obtain an error signal. The error signal is used in turn to add into all three size percentile circuits compensation or correction signals for the total volume of particules too small to be included in the measurements. This process causes the error signal to decrease toward zero, and results in all three circuits having outputs truly representative of their nominal percentiles.
摘要:
By creating at least two related raw counts N.sub.1 and N.sub.2, of particles in a fluid suspension either as two physcially derived particle counts, or one physical count and an artificial count derived from the physical count, there can be developed a mathematic function relationship by which the "scanning constant" K of a particle analyzer, for example of a Coulter type, can be factored out and a resultant equation obtained. The resultant equation is employable in operating upon the input N.sub.1 and N.sub.2 raw counts for generating the ultimately desired corrected particle count N.sub.0, which eliminates particle coincidence errors. The disclosure encompasses several methods and apparatuses by which the raw counts are developed and by which the related mathematic functions are defined and then employed to obtain corrected counts.
摘要:
A method and transfer device for transferring fluids between closed vials. The transfer device includes a cylinder having a pair of opposing open tubes or tubular portions into which a pair of vials can be inserted to transfer fluid therebetween. The tubes are separated by a wall through which extends a fluid transfer needle and a vent needle which first is inserted into a first vial to vent the first vial into a vent chamber or reservoir formed in the transfer device before the transfer needle is inserted into the first vial. The first vial, stopper first, is inserted into first tube until seated onto an exposed end of the transfer needle. A second vial, stopper first, then is inserted into the second tube until seated onto the opposite exposed end of the transfer needle. A pressure differential between the closed vials preferably can be utilized to transfer a desired fluid portion between the vials.
摘要:
A separation procedure for separating a selected desired or undesired population from a biological sample utilizing relatively heavy, dense particles and gravity sedimentation. The particles have one or more reactants bound thereto which are specific to and will bind with the selected population. The particles preferably are mixed with the sample by repeatedly causing the particles to settle through a substantial portion of the sample to bind to the selected population. The particles with the bound selected population then are allowed to preferentially settle in the sample and the supernatant including an enriched population is separated from the particles with the selected population bound thereto. The enriched populations in the biological sample supernatant can be further enriched by multiple removal steps.
摘要:
A method and apparatus for accelerating at least one definitive biological reaction including increasing the accuracy of determinations made therefrom. The reaction involves selected viable biological cells which are prepared in a small sample volume and rapidly mixed with microspheres having antibody specific at least to specific ones of the cells bound thereto. The microspheres can be magnetic and the bound cells can be magnetically removed to analyze the remaining blood cell populations. The microspheres can be introduced sequentially or simultaneously.
摘要:
A method and apparatus for automatically and rapidly, retrieving, counting and/or analyzing at least one selected white blood cell population and/or subset thereof of a whole blood sample or portion thereof. A volume of a biological sample containing the white blood cells is prepared and at least one reactant specific or preferential at least to some selected biological cells is introduced thereto and rapidly mixed for a short period of time. The opacity and/or volume parameter of the cells can be modified and the mixture is then counted and analyzed in one or more steps to obtain the desired white blood cell population analysis.The biological sample can be a whole blood sample and the reactant can include or be a lyse or a monoclonal antibody bound to microspheres, which will bind to specific ones of the cells or a combination of lyse and microspheres with antibody bound thereto. The microspheres can be magnetic and the bound cells can be magnetically removed for retrieving and analyzing the remaining blood cell population.