Search PubMed⌕ Search

Biomedical subjects

M G Nelson

Publications and source records attributed to M G Nelson.

29 records · Page 2Linked to original sources
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↗
PubMed1969

Punch card data processing in haematology.

A method of processing haematological laboratory data based on the IBM 870 system is described. As the cards are being punched with the identification particulars of the patient and source of the sample, a worksheet is automatically generated on which the tests are indicated. The results of the laboratory tests are recorded by the technician on the worksheet and reproduced on the punch cards which are subsequently used for the automatic printout of the results on self-adhesive preprinted labels. The resulting report is clear and legible and is transferred onto the request/report document. The data processing is carried out by clerk/typists who have been trained as punch card operators. The present workload of approximately 2,000 items of information obtained from some 170 samples per day is handled by one punch card operator in less than three hours. The punch cards are manipulated in a sorter for quality control purposes and are stored for subsequent retrieval of information.

Hematology↗
PubMed1965

Simultaneous free and bound radioactive vitamin B-12 urinary excretion test.

The absorption of vitamin B(12) following the simultaneous administration of (58)Co B(12) and a complex of (57)Co B(12) with human gastric juice was assessed by measurement of urinary excretion of radioactivity. Sixteen control subjects, 13 patients with pernicious anaemia, and four who had had total gastrectomy were studied. The method proved a reliable means of detecting those with intrinsic factor deficiency.

Anemia, Pernicious↗
PubMedDate not supplied

Effect of age and activity on knee joint proprioception.

Falls lead to significant morbidity and mortality in persons older than 65 years of age. Impaired proprioception may be a contributing factor to falls, and this may be influenced by the level of habitual physical activity. The primary purpose of this study was to investigate knee joint proprioception among young volunteers and active and sedentary elderly volunteers. Knee joint proprioception was measured through reproduction of static knee angles using a Penny and Giles electrogoniometer. The secondary purpose of this investigation was to test the reproducibility of the Penny and Giles electrogoniometer in measuring static knee angles. Sixteen young subjects (age range, 19-27 years) and 24 elderly subjects (age range, 60-86 years) participated. Subjects were given a screening history and physical examination to exclude neuromuscular or vestibular disorders or lower limb injuries. Knee joint proprioception was measured two times during one week. The elderly group was separated into active and sedentary subgroups based on their level of activity during the past year. The electrogoniometer was placed laterally across the dominant knee joint. From the prone position each subject attained one of ten randomly predetermined knee joint angles from 10 degrees to 60 degrees. The subject then returned to the starting position and reproduced the test angle. The absolute angular error (the absolute difference between the test angle and subject perceived angle of knee flexion) was determined. A positive correlation was found between control visits for all subjects (r = 0.88), and significant differences were observed between young (mean, 2.01 +/- 0.46 degrees) and active-fold (mean, 3.12 +/- 1.12 degrees; P < 0.001), young and sedentary-old (mean, 4.58 +/- 1.93 degrees; P < 0.001), and active-old and sedentary-old (P < 0.03). These findings demonstrate that the Penny and Giles electrogoniometer is a reproducible device for measuring knee joint angles in both young and elderly subjects. Furthermore, we found that proprioception is diminished with age and that regular activity may attenuate this decline. One strategy to reduce the incidence of poor proprioception and fall with ageing may be regular exercise.

Accidental Falls↗