Customer Handoff & Final Project Documentation
Table of Contents
Team Vision for Final Demo and Handoff
Issues continued to plague the team with the chest cavity. In order to complete the project, the team decided to utilize Styrofoam instead of ABS to create the mold for thermoforming. Five blocks of Styrofoam (7 inches x 8 inches) were glued together with wood glue. The block was cut and sanded down to the desired shape. A 1/8 inch plastic sheet of PETG was utilized to thermoform as had been done during testing. The team decided not to use the 1/4 inch sheet because of the problems experienced. In the machine shop, heat was used to form holes for the necessary fittings.
Below is the image of the chest cavity when the mold was taken out.
Blow is the image of the chest cavity with 2 out of the 3 fittings attached to the chest cavity with epoxy.
DiaphragmThe piston design could not longer be used because of the problems surrounding the completion of the chest cavity. Therefore, a new design was prepared and executed. A similar design was to be utilized as with the original model. The sheet was 3D printed using Ninjaflex. Below is the image of the 3D printed diaphragm.
Test Results SummaryThe project was not completed until the end of the semester so not all of the tests could be run. Those that were run tested: IPS pressure, lung pressure, tandem movement, and volumetric flow rate. The two pressures were tested by attaching the model to the desired instrumentation and utilizing Capstone software in the BME lab. The IPS pressure differential equated to less than 1 kPa. The lung pressure differential equated to 1 kPa depending on the intensity of diaphragm pumping on the part of the volunteer. The IPS and lung pressures are depicted in Figure 1. Comparing the values obtained to the values in Figure 1, the minimal difference in pressure does relate to the pressures created within the body during inspiration. The diaphragm is not very compliant, stretchy, which allowed for the low pressure differential. Therefore, the finalized diaphragm design is advantageous when compared to the latex.
Although the tandem movement, visual aesthetics, and ease of use were not tested by a panel as proposed, the tandem movement is evident. When the diaphragm is pumped, the pressure differential causes inhalation and exhalation. A last minute decision was to have the rib movement be separate from the pumping of the diaphragm so the ribs are not longer considered when observing tandem movement.
Lastly, the volumetric flow rate was tested by using LabChart software and a compatible flow head. The model was exercised and the tidal volume was calculated. The final, calculated tidal volume equaled 600 mL which is equivalent to that of a normal sized adult. The student is in charge of pumping the diaphragm and is in complete control of the number of breathes to be recorded per minute. Therefore, the desired 60 breaths per minute can be simulated as well as a hyperventilation case.
The final results obtained for the completed model versus the finalized engineering requirements can be found here.
Risk and Problem TrackingThe completed risk management plan can be found here.
The completed problem tracking document can be found here.
Final Project DocumentationThe final technical paper can be found here.
The final poster can be found here.
The final presentation slide can be found here.
The final Bill of Materials can be found here.
The manufacturing instructions can be found here.
The operator manual can be found here.
The service manual can be found here.