Ogden College Dean helps design PPE
- Author: Thursday, April 16th, 2020
Pictured: Converted scuba mask prototypes. On the left is the first prototype with a P100 filter attached. On the right is the second prototype with a powered air-purifying respirator (PAPR) unit attached.
Dr. Greg Arbuckle, Interim Dean of WKU's Ogden College of Science & Engineering, has been working to turn scuba masks into personal protective equipment (PPE) for healthcare workers.
Dr. Hugh Sims approached Arbuckle about this project in late March. Sims, an ENT-otolaryngologist at the Medical Center in Bowling Green, was inspired by similar efforts to convert scuba masks into PPE for hospital staff in Italy. He requested Arbuckle’s assistance in prototyping a 3D attachment to connect the filter and scuba mask. By converting these scuba masks, healthcare workers would have a reusable mask that provides full-face coverage. "We want to try and provide PPE that will stop the spread between frontline healthcare workers and patients," Arbuckle said.
Arbuckle began work on creating prototype attachments in AutoCAD, a computer aided design software. "I started drawing simple, rough designs in AutoCAD, tested to see if it fit, and started making small changes in each one as I went through," Arbuckle said. With multiple revisions to the drawings, Arbuckle overcame fit issues between the 3D printed prototype and the mask. "It's not like we have the dimensional drawings," Arbuckle noted. Their first prototype connected a scuba mask with a P100 filter. However, the prototype had a problem - a lack of airflow inside the mask. "Without some kind of forced air into the mask, the mask was very hot and not comfortable to wear for extended periods of time," Arbuckle said.
After going back to the drawing board, Arbuckle had another workable prototype to test. "We realized that we could develop a filter that would hook up to a powered air-purifying respirator (PAPR) unit directly," Arbuckle said. This change in direction improved airflow and made the mask more comfortable to wear.
Arbuckle also refined the printing process to create the adaptor. Using a plastic filament, he can print six adaptors at one time. With three hours of preparation, it takes sixteen hours to make those six adaptors. Additionally, those newly printed adaptors must spend another four hours in an ultrasonic wash tank. This additional step removes excess plastic and opens the gaps in the adaptor where it snaps into place on the mask. Printing is the longest part of the creation process. "It's the 3D printing time that affects things. It's easy to assemble - it just snaps together," Arbuckle said.
After printing the prototype, Arbuckle’s next step was to ensure the mask and PAPR unit would work with a saccharin fit test. This test determines if the mask will keep out particles. "A person wearing the mask and adaptor gets inside a hood and sprays saccharin (a sweet-smelling chemical). If they can smell or taste it, [the mask] fails the test," Arbuckle explains. "Once we get a good saccharin fit test, we are hoping to find a method of supplying a full list of what is needed," Arbuckle said.
Arbuckle and Sims plan to release the schematic file for this adaptor online and make it available for hospitals and other medical facilities across the country. So far, Arbuckle has produced 8 masks that successfully passed a saccharin test. "We want to open source the drawing to allow as many people to print these adaptors as possible," Arbuckle said.
To learn more about the WKU Ogden College of Science and Engineering, visit www.wku.edu/ogden.