| Description |
Electrical impedance measurements were taken on 269 samples of human urine to compare the mean impedance of abnormal urine to the mean impedance of normal urine. Samples obtained from the population of specimens sent to The University of Utah Clinical Chemistry Lab were assigned to seven different categories based on their urinalysis results. The methodology controlled for the following variables: (1) solution volume; (2) type, size and distance between electrodes; (3) frequency and amperage of the input current; and, (4) temperature of the solution. Impedance measurements were taken using a High Resolution Impedance Convertor (Transmed Scientific Model 2991), which provided 50 uA constant current at 50 kHz. The results of this study indicate that: (1) There is no significant difference in mean impedance between normal urine and urine containing higher than normal amounts of either red blood cells, white blood cells, protein, glucose, bacteria, or Pyridium; and, (2) there is a significant difference between the mean impedance of normal urine and urine that is either concentrated (specific gravity ? 1.025) or dilute (specific gravity ? 1.003). It was also found that impedance readings varied considerably within each category. These findings suggest that factors other than those identified for this study may significantly influence the electrical impedance of human urine. |
