Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04783688 |
Other study ID # |
Pro00106241 |
Secondary ID |
|
Status |
Completed |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
March 9, 2021 |
Est. completion date |
June 11, 2021 |
Study information
Verified date |
March 2021 |
Source |
Duke University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Recently, multiple models of Full Face Snorkel Mask (FFSM) have entered the retail market.
However, several fatalities have been reported to the non-profit agency Divers Alert Network
(DAN) for snorkelers who were using FFSMs, and most of these fatality reports have unclear or
unreported causes of death. This project is to determine the characteristics of the FFSMs
when they are in use by snorkelers. Volunteers will be asked to snorkel in a water tank while
breathing through several models of commercially available FFSM, one at at time.
Description:
The scientific testing will take place in the water tank of Foxtrot chamber at the Duke
Center for Hyperbaric Medicine & Environmental Physiology. This Center (referred to as "Duke
Hyperbarics") has a long history of testing various aspects of undersea physiology and causes
of injury and death. Duke Hyperbarics will conduct the physical tests, and DAN (Divers Alert
Network) personnel will also supervise the scientific testing.
The experimental test subjects will be divided into two categories. Before testing, both
categories will come in for a screening day, where they will go through the informed consent
process and be medically screened for safety to perform activity. For the first category of
subjects (Group A), five volunteer subjects will be recruited with no restrictions on age or
fitness level. An effort will be made to include representative test subjects from older age
ranges (>35 years old) in this group. To ensure they can safely perform light activity, they
will be screened for cardiovascular disease, both by questionnaire and by a physical exam
during the screening day.
The second group (Group B) will be age 18-40, non-smoking, and screened for fitness using a
physical exam and a VO2max test. The reason for these two groups is to ensure that a spectrum
of test subjects is examined across the comprehensive range of ages and fitness levels that
may participate in snorkeling as recreation.
The testing will be designed to assess the function of the FFSMs produced by multiple brands
compared to each other as well as compared to conventional snorkels. Test subjects will be
positioned horizontally in warm water. They will be face-down on a bicycle ergometer,
grasping handlebars for stability. On the test day, each subject will undergo three test
procedures, using first a conventional snorkel then two different brands of FFSM while
pedaling the underwater bicycle. Group A will be asked to pedal at a rate that is comfortable
for them, while Group B will be given a targeted higher work rate to achieve.
For each FFSM test, the test subject will be asked to place the mask on themselves but
provided no further instruction. The pressure exerted by the mask on the forehead will also
be measured by placing a small, flexible, force-sensitive gauge between the skirt and the
skin (this gauge needs to be in place for only a few seconds and will be removed before
snorkeling). At the end of each test, the subjects will be asked to remove the FFSM quickly
in response to an audible or visual alarm that will appear three times at randomized
intervals. Their ability to remove the masks quickly will be timed.