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Biomedical subjects

A Lamont

Publications and source records attributed to A Lamont.

47 records · Page 3Linked to original sources
PubMed1972

An evaluation of the Celloscope 401 electronic blood cell counter.

For counting erythrocytes the instrument was precise, with a mean coefficient of variation of 1.21%. Erythrocyte counts showed close agreement with results obtained on a Coulter A electronic counter of proven accuracy. When the Celloscope 401 was modified by the manufacturers to eliminate electrical interference from other laboratory equipment, satisfactory precision and accuracy for white cell counting was obtained. Using cetrimide diluent the coefficient of variation was 1.6% but when using saponin/saline diluent the coefficient of variation was 3.5%. For leucocyte counting there was close agreement between duplicate tests performed on the Celloscope 401 and the Coulter S. The instrument was capable of satisfactory precision and accuracy in platelet counting, provided that the sedimentation method was used to obtain a platelet-rich plasma. The best results were obtained if a two-step dilution was carried out with a first dilution in 10% EDTA and a second in 2.5 mM cocaine in water. Using this method the precision study indicated a coefficient of variation of 3.11%. Close agreement was obtained between platelet counts on the Celloscope 401 when compared with the results obtained either by phase-contrast microscopy or using another electronic counter. Allowing for predilution and duplicate counts on each sample, the rate of throughput was approximately 32 samples per hour. Throughout the test period, the instrument remained electronically and mechanically stable.

Blood Cell Count↗
PubMed1970

An evaluation of the Fisher Hem-Alyzer.

The Fisher Hem-Alyzer is a multitest sequential discrete analyser with automatic printout of digitized results on paper tape. The instrument is well designed, soundly constructed, and reliable in routine use. Cross contamination from the sampler probe or between the cuvettes is minimal. Accuracy and precision are both highly satisfactory. Although the standard rate of throughput is 32 specimens per hour the instrument can be used at irregular intervals to analyse smaller batches or even individual specimens. In a routine daily service the Hem-Alyzer was capable of handling a workload of 200 specimens per day, requiring three hours of laboratory technician time. The Hem-Alyzer produces only three parameters. By not determining the packed cell volume it is not possible to incorporate the derived indices (MCV and MCHC) into the system and this, in the long term, is bound to be a disadvantage.

Autoanalysis↗
PubMed1969

An evaluation of the autoanalyzer SMA-4.

The Technicon AutoAnalyzer SMA-4 has been systematically evaluated. Carry-over from the sample cups was found to be within an acceptable range. The precision and accuracy of the four parameters determined by the instrument have been investigated. The haemoglobin results were found to be accurate. There was good agreement with leucocyte counts performed on the model A Coulter electronic cell counter. After certain modifications had been made in the manifold, satisfactory degrees of accuracy were also obtained for the erythrocyte counts. Although the determination of the haematocrit by conductance is influenced by a variety of factors, the mean coefficient of variation was found to be 0.83% and 95% of the results agreed within +/- 2% of those obtained by the microhaematocrit centrifugation method.A logistic assessment of the SMA-4 when it was put into routine use indicated the need to select blood samples without excess anticoagulant, to calibrate the instrument before each run, to test for instrumental drift, to use a rapid method of correcting stoppages, and, if concurrent reporting is carried out, to employ the part-time services of a second operator. The presence of dust in the environment was found to have a deleterious effect on both the mechanical and electronic components of the system requiring preventive maintenance. It should be possible, by interfacing an analogue-digital converter and automatic punch, to produce data compatible with records.

Analog-Digital Conversion↗