Clinical Translation of the iMASC System
Clinical trial evaluating mask fitting
In a prospective trial, we enrolled 24 healthcare workers at a large, urban, academic medical center who had been previously certified to wear a N95 respirator into our IRB-approved study. We excluded individuals with significant facial hair or those that had failed a N95 fit test. Consenting individuals were subject to a fit test as defined by the United States Occupational Safety and Health Administration (OSHA). Briefly, participants first placed the iMASC system on their face and molded the nosepiece to ensure an adequate seal. Next, the participant’s head and face were placed in a plastic hood, and a saccharine solution was sprayed into the enclosed space as guided by OSHA. Participants were asked to perform four maneuvers:
- rotating head in the lateral plane,
- moving the head up and down,
- verbally counting down backwards from 100 to 90 and
- bending at the waist.
A passing test was defined as no detection of saccharine solution by study participants. The median age of participants was 41 years with a range of 21-65 years with an average BMI of 26.5. The breakdown of participants by profession was 46% nurses (n=11), 21% attending physicians (n=5), 21% resident physicians (n=5), and 12% technicians (n=3). Of these participants, 4 did not perform the fit testing (1 due to inability to detect saccharin solution on pre-mask placement sensitivity test, 2 due to time, and 1 due to fit of the mask on her face). All participants (n=20) that performed the fit test successfully completed the fit test as part of the hospital annual policy. All participants passed their fit test and were also able to successfully replace the filter into the mask, resulting in a 100% success rate for both fit testing and filter exchange.
User experience with the iMASC system was evaluated using a Likert scale with a score of 1 indicating excellent and a score of 5 indicating very poor. Of the 20 participants, the average fit score of the mask was a 1.75. Participants on average scored the breathability of the mask as a 1.6 with a median of 1.5. Finally, ease of replacing the filter on the mask was scored on average as a 2.05 with a median score of 2. Participants’ preference to wear the iMASC over a surgical mask or an N95 respirator was also assessed. Sixty percent of participants indicated they would be willing to wear our mask instead of a surgical mask, with 20% indicating no preference between our mask and a standard surgical mask and 20% indicating they would prefer to wear a surgical mask. When asked about preference to wear our mask instead of an N95 respirator, 25% of participants indicated they would prefer to wear our mask and 60% indicated no preference between our mask and a standard issue mask, with only 15% indicating they would prefer to wear a standard issue N95 respirator.
Figure 1: Demographics of participants (N = 24) enrolled in fit testing clinical trial. (B) User experience (N = 20) with the mask based upon a Likert scale. (C) and (D) User preferences (N = 20) comparing the iMASC system to the standard surgical mask and N95 respirators.