Tissue Smearing Plate

Glioblastoma is a highly aggressive form of brain cancer that presents significant challenges in diagnosis and treatment, impacting patients' quality of life. This report outlines an innovative device developed to smear multiple tissue samples at once, to increase efficiency in the analysis process and thus reduce time for overall detection and treatment of glioblastoma. The device will help standardize and optimize the process of smearing to ensure consistent samples are produced without damaging cells. 

Stakeholder needs were carefully considered, identifying six important groups: surgeons, glioblastoma patients, pathologists, researchers, manufacturers, and the provincial government. Based on their needs, key consumer requirements were determined, and a Quality Function Deployment (QFD) was developed. The key requirements included ease of use, durability, a smooth smearing surface, and fluid channels. The device should ensure even force distribution on the cells and be easy to clean. Additionally, the design must allow optical clarity for transmission optical microscopy, be purely mechanical, compact, and minimize dye waste.  

A parallel design process was used to develop and evaluate multiple concepts simultaneously. Based on team feedback, the designs were iterated to better meet customer requirements. The designs were evaluated using the Weighted Evaluation Matrix (WEM), Failure Modes and Effects Analysis (FMEA) and a cost-analysis. Sensitivity analysis indicated that the criterion of accurate smearing significantly influences outcomes, necessitating careful attention in the final design. The final design was chosen due to its balance of usability, cost-effectiveness, and reliability.  

Finite element analysis (FEA) was used to perform stress testing, and a reliability analysis were performed on the device. It is proposed that the body of the device will be machined using Stainless steel 304, and the handle will be 3D printed using Polycarbonate. For the client, in addition to the computer-aided model (CAD), device instructions and a cleaning protocol will also be provided. 

By improving the speed and accuracy of glioblastoma diagnosis, our device has the potential to significantly impact patient outcomes and healthcare efficiency.  

Problem Definition

The current biopsy testing process is time and labor-intensive, requiring pathologists to manually smear samples onto glass slides. This method, while acceptable, is dependent on user skill and can be prone to inconsistencies between samples due to human error. The team’s goal is to develop a mechanical smearing device that can smear multiple samples simultaneously and standardize the compressive and shear forces applied to the samples.  

During the design process, all stakeholders and their requirements were considered. Key stakeholders were identified for this project by considering the device lifespan and all potential user interactions. The six key stakeholder groups identified are surgeons, glioblastoma patients, pathologists, researchers, manufacturers, and the provincial government. 

It is assumed that users of this product will have an appropriate technical background as well as laboratory or clinical experience. For this project, murine brain tissue was used in preliminary testing, because it is assumed to show similar behavior to human brain tissue. 

The device should be easy to use, durable, and designed with smooth surfaces for effective smearing with even force distribution. It must be easy to clean, biocompatible, ensure optical clarity for microscopy, mechanically operated, compact, reliable, and minimize dye waste.  

Microscope Pictures

Dr. Purzner conducted two additional smears for visual analysis. The demonstration involved the compression and subsequent smear of the two microscope slides with the murine tissue in between. This sample, once smeared, was put under the microscope at 40x magnification to view the cells. The results of the smears are shown below.

Viable Cells Smeared Microscopy

Crushed Cells Microscopy

Design

Our final design consists of five key components: base body (1), smear plate (2), microscope slide (3), silicon sticker template (4), and the handle (5).

These parts work in unison to ensure ease of use and precision in tissue smearing.

Step 1: The user presses the top plate down onto the base plate, compressing the tissue sample 

Step 2: The user smears the sample by sliding the top plate along the guide rails until the mechanical stoppers halt the motion, ensuring consistent smearing. 

Video Demo

Concluding Statement

This innovative smearing device addresses critical challenges in glioblastoma diagnosis by improving efficiency, accuracy, and sample consistency. Developed through a stakeholder-driven process and validated with rigorous analysis, the device balances usability, reliability, and cost-effectiveness. By enabling faster and more accurate microscopy, it has the potential to significantly enhance patient outcomes and healthcare efficiency.