The American journal of medical technology最新文献

In summary, it is our conviction that each clinical hematology laboratory must perform a rigorously controlled primary whole blood calibration of their ELT-8 or other CBC instrument. Commercial controls should be obtained from more than one source, and assayed by each laboratory. The ELT-8 Control Libraries are a convenient electronic medium for storage of these assay values and subsequent accumulation of control runs. The moving average library needs to be configured for mean value and ranges by each laboratory and serves as an extremely sensitive real time monitor of instrument performance as well as a guide to the use of stable commercial controls.

As the use of laboratory techniques in diagnostic medicine increase, it became obvious that standardized reference methods and stable controls were essential in order for results obtained in different laboratories to be comparable. Certain procedures and standards have been adopted to provide QC in hematology. Currently procedures include the following: cyanmethemoglobin for HGB determinations; particle counter for RBC and WBC counts; phase microscopy for PLT counts; and packed cell volume for HCT determinations. These serve as acceptable reference methods for multichannel hematology instruments. Instruments that are used must be carefully calibrated. Calibration of the spectrophotometer should be performed using an acceptable standard for hemoglobin. Calibration of the particle counter to determine RBC and WBC counts should be performed using a fresh sample of anticoagulated (EDTA) blood. PLT counting by phase hemacytometry should be used to obtain reference values for automated PLT counters. Centrifuges that are used to obtain microhematocrit values should be calibrated for maximum packing times and times checked against an electric clock. After the instruments have been calibrated, fresh whole blood is measured to determine a target value for each determination. Primary calibration of multichannel instruments is performed by calibrating each parameter to the target value. This is performed initially and then once each week. Two techniques that are commonly used to monitor instrument performance are: 1) the use of at least two levels of commercially prepared control samples to prepare either Levey-Jennings charts or the simple Cusum charts, which detect presymptomatic instrument problems; and/or 2) the use of 500-1,000 patient indices and mean WBC counts analyzed by the XB statistic to establish limits for monitoring instrument performance.

Quinidine is a commonly used drug for the treatment of cardiac arrhythmias. Avoidance of toxicity and monitoring of therapy can be readily accomplished by determining serum concentrations of quinidine by enzyme immunoassay (Emit) using a centrifugal analyzer and reducing the data with a desk-top microcomputer. For therapeutic and toxic drug ranges maximum within-run CV was under 6.0%, while between-run CV was under 10.0% in the therapeutic range and under 15.0% in the toxic range.

Instruments designed by Kolb, Canfield, and Rezler-French have been used to measure the learning style preferences of students in several health fields. The majority of students in these fields prefer learning in concrete, active experimentation, and teacher-structured formats. Using the Rezler-French instrument the learning preferences of medical technology (MT) and physical therapy (PT) students were studied. It was found that their first preference was on the concrete scale and that their second preference was on the teacher-structured scale.

Establishing thorough maintenance and operational protocols for multichannel hematology instruments is an integral part of any QC program. Implementing appropriate collection techniques and properly informing the technical staff about all protocols are equally important. Selecting standards and/or controls for use on the multichannel instruments frequently presents difficulty. However, fresh WB samples (EDTA, 1 mg/ml) can be used to calibrate the instruments periodically. Additionally, data from the Coulter S-Plus II print-out of WB patient samples can be statistically evaluated using R and/or XB statistics to monitor instrument performance.

Two major viruses have been clearly associated with gastroenteritis: the Norwalk agent and the rotavirus. The former is associated with epidemic outbreaks in adults or schoolchildren, while the latter causes endemic illness in young children during winter. Neither can be grown in routine cell cultures. Both of these viruses, and others, can be detected in patients' stools by electron microscopy. Enzyme linked immunosorbent assay (ELISA) kits are commercially available for detection of rotavirus antigen in stools. This test, which can be readily performed in the routine laboratory without specialized equipment, offers useful diagnostic and prognostic information.

Cognitive style addresses the individual's unique preference for learning. Cognitive style differs from ability, achievement, performance, and productivity in that it is not measured quantitatively; it is value-free. Non one cognitive style is better than another. It is established in early childhood and remains stable. Cognitive style information has immediate use for those in an academic setting and those in any setting requiring effective communication. Cognitive style information has been widely used in medical settings, schools, hospitals, post graduate training and patient instruction. A practical model used in community colleges and in medical education is the Modified Hill Model. In that model 28 elements are assessed and the resultant "map" presents a graphic picture of learning preference. Research indicates that knowledge of cognitive style is effective in improving academic achievement and person-to-person communication. In medical technology, cognitive style can be effectively used in teaching (students, staff or patient), in work group communication, and in informing the many publics of the vital role played by medical technology.