College of Engineering
Biomedical Engineering Department
BS in Biomedical Engineering
Christopher Heylman, Michael Whitt
This project aims to integrate an automatic gas release system in a pre-existing scaffold fabrication process for tissue engineering applications.
To form the proper scaffold structure, the fabrication process is heavily influenced by the change in its surrounding pressure. The current production involves a pressure transducer and electric valve that is managed manually to create a suitable pressure environment for the scaffold. This method, although functional, proves to be ineffective when creating several batches; the user needs to constantly monitor the developing pressure profile and alter voltage parameters accordingly to create a linear gas release under a predetermined slope.
To alleviate this problem, this project designed and implemented a feedback loop within the present system. This would allow the user to set a time frame for the gas release, thus directing the system to produce the desired pressure profile. The negative feedback loop follows a set line equation in conjunction with a Boolean case structure that dictates how the release valve must behave to create the user-defined pressure drop.
The constructed LabVIEW code was tested in its performance in the following categories: linearity in the pressure profile produced, variability between the set point equation and the actual pressure drop, usability of the graphical interface, and electric valve response time. Applications of test protocols showed that the LabVIEW code achieved its intended function and improved upon the predecessor system currently in use in the laboratory.
This project also incorporated a design and build of a housing unit to hold the components involved in the pressurization process. The procedure requires a tube-like pressure chamber with a top-heavy electric valve attachment that causes the center of gravity of the apparatus to shift when in use.
The manufactured housing unit was tested in the following criteria: variability in angle measurements, and structural stability during use at extended periods of time. Implementation of the test procedures revealed that the manufactured housing unit was structurally sound and stable. The housing unit is now used in the laboratory.