Reports

Subpages:

• Budget

  • CAD files 

  • Docs files

  • Parts used in final product

Executive Summary

    Blood smears are commonly used in hematology labs to diagnose many hematological disorders such as sickle cells or leukemia. Manual smears are made by placing a drop of blood on one glass microscope slide and using another slide to smear the blood along the first glass slide. This process often results in inconsistencies between technicians and an inability to vary the smearing speed or angle that is required by the hematocrit, the volume percentage of red blood cells in the blood. Without consistent smearing results, the accuracy of the test results are compromised and potentially invalidate with any diagnostics made. Alternatively, there are companies which produce large all-inclusive devices, such as the Sysmex SP-1000i, that create consistent and completely automated smears; however, these devices tend to be costly and only larger labs are able to purchase these. The goal of this project was to create an alternative to the Sysmex SP-1000i and other smearing devices at a lower production cost for availability in smaller hematology laboratories. A few initial design requirements for this project include:

• • A small laboratory device that requires minimal lab bench workspace

  • A low cost solution with a budget below $2000

  • User friendly set-up and minimal technical interaction with said device

  • Consistent quality smears comparable to those smears created by other devices

  • Eliminate cross-contamination between samples

The final design, shown partially in Figure 1,  successfully created automated smears and required little user interaction with the mechanical aspects of the device. The slide was secured to a 3D printed slide platform which was mounted onto a belt-driven linear actuator. This linear actuator was the main component of all subcomponents in the device as its primary function was transporting the slide safely and smoothly from one location to the next. The smearing unit was custom made to hold PerfectSmear Blades which were purchased for this project based on their low cost and one-time-use functionality to eliminate cross-contamination between samples. These blades would be disposed of automatically in the disposal unit on the side of the device. All the electronics were securely wired and connected onto a PCB and held within the electronics compartment. To simplify user interaction with the device, a touchscreen LCD was used and automatically displayed a graphical user interface. Finally, an enclosure was created using acrylic and 80-20 aluminum t-slots for security and minimal risk of contamination.

Figure 2 shows smearing results made with the device. These smears were made with pig blood as opposed to human blood. The smears are consistent in length and quality, validating the devices ability to create consistent smears. However, there is noticeable chattering in this smears, as seen towards the end of the smears. This defect is a result of vibrations in the linear guide system. This is one aspect that can be improved about the device but, overall, the prototype successfully proved that a cheap alternative to the Sysmex device is possible.

3/21/19 Risk Reduction Presentation