A computer program to aid in learning differentials and morphologies.

IN HEMATOLOGY, as in all areas of clinical pathology, it is possible to recognize "abnormal" only if one is thoroughly familiar with "normal." Not so many years ago, all differentials and morphologies were performed at the microscope with the majority of the slides examined being normal. This provided student technologists with the perfect environment for learning to recognize "normal." The student could sit beside a teaching technologist and receive immediate feedback on performance and progress. Once the necessary proficiency was achieved with normal films, the student could move on to abnormal ones.

* Changing learning environment. The introduction of automated particle counters, capable of performing three- and five-part screening differentials, has changed not only the workload in modern hematology departments but also the teaching and learning environment. The number of leukocyte differentials and erythrocyte morphologies examined microscopically has decreased markedly, and much less time is spent examining normal blood films. For proficient technologists, this is a boon. For students, however, these automated instruments have made it more difficult to develop proficiency in performing differentials and morphologies.

Because of this new technology, it is important that student technologists receive more preparation in the performance of differentials and morphologies during their didactic years. Financial and time constraints, however, have increased the student-to-instructor ratio and decreased the amount of laboratory time available for initial instruction in performing these tasks.

* Common approaches. A number of approaches have been used to provide students with the opportunity to perform more differentials. A more common one is to make available a collection of slides for students to examine. After examining the slides, students hand in their results for review by the instructor.

Another approach is to provide both the slides and the correct results. Students examine the slides at a convenient time and compare their results with the results recorded in a binder or file.

Several deficiencies exist with these systems. First, they bear no resemblance to what goes on in a modern clinical laboratory. Second, the students can record the differential and morphology results from the binder before they have examined the film. Third, the instructor can't know if, in fact, a student examined the slides, how many times the slide had to be examined to get the correct results, or if a student is having difficulty. Fourth, ever-increasing workloads mean that it is often several days after handing in results that students see how they performed. By this time, it is unlikely that students or instructors will go back to the slides to see exactly where errors were made.

* Object-oriented languages. Personal computers (IBM-compatible or Macintosh) have become more available in the last few years. They are less expensive, more powerful, and easier to use than they were 5 or 6 years ago. More importantly, they are much easier to program by using the new object-oriented languages.

Languages such as "Hypertalk" (Apple Computer, Cupertino, Calif.) and "Plus" (Spinnaker Software, Cambridge, Mass.) allow a programmer with even limited experience to write complex programs that would have been very difficult to write with the earlier linear languages. In addition, programs written with these languages can be ported from one platform to another. That is, a program written in Hypertalk can be converted to a Plus program and will run on an IBM-compatible PC under DOS 5.0 and Windows 3.1. Similarly, a program written on an IBM-compatible using Plus can be convened to run as a Plus program on a Macintosh. The conversion is extremely fast and not much more difficult than saving a word processing document on either system.

* How the program works. Using Hypertalk, we wrote a program that: provides students with the cell panel before examining the slide; accepts the results of the differential and morphology; records which students examined which slides and what their results were on each slide; and provides immediate feedback in the form of the actual results and a percentage grade.

Using this system, a student selects a blood film from a slide box and enters his or her name and the slide number into the computer. The program checks to ensure that the student name and slide number are valid and, if so, displays the results for the cell panel. The program does not display the correct differential or morphology at this time.

After examining the cell panel and histograms, as would be done in a real lab, the student proceeds to the microscope to perform the differential, erythrocyte morphology, and platelet estimate. Students can enter these data in any order they wish. The differential is entered as a percentage, the RBC morphology is entered as a single digit from 0 to 4, and the platelet estimate and platelet morphology are entered as 1 for decreased or microcytic, 2 for normal or normocytic, and 3 for increased or macrocytic.

Students can enter any WBC or RBC anomalies by selecting the "WBC anomalies" or "RBC anomalies" buttons. Either button displays the appropriate list of anomalies. Students then enter 1 to 4 to indicate the relative frequency of the anomaly they feel is present.

Once students are satisfied with the data they have entered, they depress the "All data entered" button. At this point, and at this point only, the program displays the correct data in bold, alongside the student data. The program determines if the student result is within one standard deviation of the correct result. If so, the student receives full marks for the result. A final percentage score is then calculated and displayed.

The program then follows the grade with a series of questions: Is an anemia present? If so, what is its morphologic type? Is there a leukocytosis? Are the RBC, WBC, and platelet histograms normal? What condition most closely correlates with the presented data? The answers are graded and a question score is displayed, followed by a total score. The slide number, student name, all student data, the student scores, and the correct data are then stored in a special file that can be reviewed by the instructor at a convenient time.

Any discrepancy between the correct and student results is immediately seen by the student; they can return to their microscopes and attempt to correct the differences. If they are unable to do this, they can note the errors and discuss them with the instructor at a later date.

* Hefty investment, but worth it. The program has been written in such a way that new data can be entered easily. In addition, it is easy to retrieve and examine student records in a variety of ways. Although the preparation was time consuming, the program now provides us with a great deal more time to spend with students who need help in becoming proficient at performing differentials and morphologies.

The students have found this to be an extremely effective and convenient manner in which to practice their differentials and morphologies. They are able to receive immediate feedback and progress at their own pace.

To obtain a copy of this program, please send a 3 1/2" floppy disk, a self-addressed stamped return mailer, and a check for $25 made payable to Frederick A. Rice to: Medical Laboratory Sciences Program, University College of the Cariboo, Box 3010, Kamloops, B.C., Canada, V2C-5N3. Keep in mind you must have Hypertalk or Plus in order to run the program.

Frederick A. Rice, RT(CSLT)ART, CLS(NCA) The author is an instructor in the medical laboratory sciences program at the University College of the Cariboo in Kamloops, B.C.