To test the device, a SOLIDWORKS flow simulation was created. Fluid Flow simulations revealed that the tube design, and by extension the overall device design, would work effectively and as intended. At a pressure differential of 25 Pa, the flow simulation revealed an average velocity of 0.248 m/s. Surface plots of where the insulin exits the tube revealed that maximum flow occurs towards the center of the tube, with laminar flow affecting the flow rate of the insulin at the very edges of the tube (shown below in Figure 6). After all iterations of the flow simulation were run, a clear asymptote was displayed on the graph which plotted iterations against velocity (figure 7).
The necessary information & procedures needed to conduct the flow simulation were obtained through an exploration in which the flow of insulin through a tube was analyzed. Because the SolidWorks material library did not have insulin as a pre-loaded fluid, it was created as a user-generated fluid. The flow simulation was conducted using an arbitrary pressure difference between the insulin reservoir and the end of the tube. Due to fluid flowing perpendicular to an opening creating a lower pressure around the orifice, the pressure differential was reasoned to be a difference of 25 Pa. The simulation was run at 310.15K (internal body temperature) for a total of 150 iterations. The mesh size was 150, 150, 75 (x, y, z). The flow simulation was not done to prove the exact flow rate of the insulin, but rather to demonstrate that the tube design for insulin transport would allow for effective insulin delivery to the patient.
Figure 6: SolidWorks flow simulation surface plot Figure 7: velocity vs. iterations
Additionally, research was conducted to determine if the device met all the requirements. For example, the device case is made from titanium, which is a safe material for implanting. The size of the device was greater than 4 cm, which was the requirement that it did not meet. With two batteries, the device lasts for a year, and the insulin must be replaced every two weeks. Also, the device connects to the user’s mobile device.