College - Author 1
College of Engineering
Department - Author 1
Biomedical Engineering Department
Degree Name - Author 1
BS in Biomedical Engineering
College - Author 2
College of Engineering
Department - Author 2
Biomedical Engineering Department
Degree - Author 2
BS in Biomedical Engineering
College - Author 3
College of Engineering
Department - Author 3
Biomedical Engineering Department
Degree - Author 3
BS in Biomedical Engineering
Date
6-2021
Primary Advisor
Britta Berg-Johansen, College of Engineering, Biomedical Engineering Department
Abstract/Summary
The purpose of this project was to design a device that interfaces with the previously created gap balancer to simultaneously measure the gap between the femur and tibia and measure the tension in the ligaments of the knee. First, we met with Dr. Delagrammaticas to outline the key customer requirements: we wanted the device to be precise, sterilizable, reliable, and compatible with the gap balancer. Based on the customer requirements, we outlined the specifications that would drive our design and testing, which included precision, ease of use, size, and material properties. The design process began by using a morphology to select a method to measure tension. After selecting the “slipper method” for our tension measurement method, we sought to determine the best shape to make the CAM wheel. We decided on a circular CAM wheel after analysis showed that more complex shapes would not significantly improve the design's functionality, but would increase the manufacturing complexity. We then chose a threaded knob as our tension setting and locking mechanism due to its intuitive and easy to manufacture nature. After constructing a design that fit our requirements and specifications, we outlined machining and manufacturing plans which were performed in the following weeks to create a functional prototype. We then outlined and executed test plans that aligned with our engineering specifications. After performing these tests, we found that our device met our specifications for precision, most of our specifications for ease of use, and our specifications for size and reliability. However, we found that our device did not meet the specification for gap balancer user interface visibility or the specifications for material properties. Necessary alterations to our design that must be made to meet these specifications are outlined at the end of this report.
URL: https://digitalcommons.calpoly.edu/bmedsp/154