The electronic canvas: teaching with computer graphics. With commercial software, this hematology lab created a short microcomputer course on the morphology of peripheral blood cells - and displayed drawings of cells.
Hard-copy hematology learning packages may be sprinkled with photomicrographs, but such products are often complex and inconvenient. In addition, students who learn to identify blood cells from a single set of atlas photomicrographs lack the experience and flexibility to recognize the wide range of variations in normal cells.
When we found a personal computer program with which we could create line drawings of blood cells, we set about designing a computer-assisted instructional presentation in basic morphologic hematology. It was constructed and is used on an Apple II Plus microcomputer. Here's how we did it.
Our basic-level, self-teaching unit reviews the classification and differentiation of normal peripheral blood cells. We use it to orient new employees, as a refresher course for part-time or less experienced personnel, as a review for technology students.
We developed the presentation in two stages. First, we created illustrations of blood cells with a program called the Koala Micro Illustrator (Koala Technologyies Corporation, Sana Clara, Calif.), which consists of a touch-sensitive electronic drawing pad and stylus, and graphic options that are displayed in the "commands" menu screen (Figure I). The Koala Micro Illustrator generates circles, squares, disks, and other shapes, and also lets the user create free-hand drawings. Its "brush set" changes the width or style of the line drawn by the cursor. When using a color monitor, choices of hues are displayed in the "color set" at the bottom of the commands screen. With a black-and-white monitor like ours, colors are repreented by textures--stripes, stippling, and so on.
We drew the blood cells by using the Koala pad and stylus like paper and pencil, together with the freehand draw command. This gave us the cytoplasmic membrane and the nuclear membrane. Next, we painted colors (that is, textures) on the cells and nuclei with the fill command. As we drew on the pad, the cell appeared on the screen. We changed the style of the line to fit our needs.
Once satisfied with our depiction of a cell--having corrected or redrawn it as necessary with the erase command--we gave it a name and stored it with other previously illustrated cells on a separate disk, using the storage command. We can recall any cell from storage by entering its name.
We drew 10 peripheral blood cells for the package: RBC, platelet, band neutrophil, segmented neutrophil, normal and variant lymphocytes, two monocyte variations, eosinophil, and basophil. Examples are shown in Figure II.
In the second stage of constructing the presentation, we wrote descriptive text for each cell and merged it with the corresponding drawing. We used a program called Executive Briefing Session (Lotus Development Corp., Cambridge, Mass.) to write the text. This created what amounts to a slide show, in which each screen or information display is a slide.
Screens in the Executive Briefing Session program can take the form not only of text, but also of graphs, tables, and charts. Our presentation contains some screens of full text and others of text and illustration (Figure III).
Once entered, screens can be reshuffled and presented in any desired order. Executive Briefing Session provides other options: screens can be advanced automatically or manually, and by different cutting techniques, such as dissolves or curtains.
We found the Koala Micro Illustrator adaptable to our drawing needs. Combining text and illustrations via the Executive Briefing Session program was easy, too. We can also make hard copies of the presentation because we have access to a printer with the necessary graphics capability.
The most gratifying aspect of our learning package is its simplicity. Staff members and students who use it need no knowledge of programming. They turn on the system, and the presentation begins by explaining how to advance and reverse screens--just press a single key to go in either direction. They must change disks if more than one disk is used. But having a second drive, as we do, facilitates this task.
When we designed this presentation, we wanted to give staff members and students a chance to review or update their knowledge of peripheral blood cells without the assistance of other personnel. They could choose a convenient time and review portions as required. In time, their experience with this kind of presentation will allow us to evaluate its effectiveness as a teaching aid.
There's one major advantage in the schematic representation of normal cells. It can heighten technologists' ability to identify normal variations of mature leukocytes when performing differential counts. They are not locked into the specific colors or shapes that they would learn in an atlas of photomicrographs.
The colors available on the Apple II Plus are too limited to even remotely illustrate human blood cells, but even before knowing that, we had chosen to create our package in black and white. Blood cell colors depend on staining techniques that vary from lab to lab, so we prefer to have technologists learn the patterns and textures of chromatin and granulations, for example, because they are more reliable guides to what appears under the microscope. This should make it easier to identify normal cells. When it's helpful to know the color of a portion of a cell, our text describes it.
Less experienced technologists performing differential counts routinely pass along slides with immature cells, abnormal cells, or both to personnel with greater expertise. Encouraged by our initial computer graphics efforts, we intend to design an intermediate-level package that will present immature cells and variations from normal in the cells studied in the basic package.
How far this will lead depends on how adept the computer program is at generating and displaying the subtle distinctions that separate normal cells from immature cells. Our early results are promising enough to make it worth a try.
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|Author:||Beam, Kenni B.; Dotson, Mary Ann|
|Publication:||Medical Laboratory Observer|
|Date:||Aug 1, 1984|
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