F.I.S.H. Testing

Air Force Research Laboratory engineers test the Flashing Indicator of Swimmer’s Health system at Wright State University, Dayton, Ohio, November 27, 2019. F.I.S.H. is a personal underwater blood-oxygen monitor that detects potential blackout conditions and alerts users. (U.S. Air Force video by Christopher Decker and Jose Sanchez Alonso)

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So today, what we’re doing is an extension of a project that’s been going, probably over the last two years. It started with us designing an in-house oxygen saturation sensor to address safety concerns with water competence trainees. Right now, there’s instructors on the edge of the pool looking for any signs of fatigue. But, the problem with that is sometimes there’s upwards of 40 trainees in the pool at any given time. So, it’s not hard to imagine that there might be some things that go unseen.

[Trainee] 92%.

[Instructor] What this system’s deigned to do is create an overt alert system that can draw an instructor’s attention to a trainee that might need some help. So, it’s not designed to make the training any less rigorous. It’s also not a diagnostic tool. It’s just to let them know who might be closer to potentially passing out. So, we started with a sensor we built in-house. We validated that system and we worked with a company. And they’re attempting to mass-produce our design. So, what we’re deliberately doing out here is testing their first prototype and comparing it to our industry-accepted system already.

So, at the training school, they train at depths of up to 18 feet. So, we want to ensure that their LED can be visible from the surface at depths of up to 18 feet. Another aspect is accuracy of the system while a swimmer is wearing it and we want to make sure that it actually is waterproof. And there are fitness watches that measure oxygen saturation and they’re already in a watch form detector. And we keep being asked the question “Why can’t we use those?” Those aren’t designed to be used under water in a very dynamic situation where you have water sheer passing between the sensor and the body. So, the sleeve is a limitation of the current design and current technology. The sleeve is there both to hide the lead, the wire, the sensor lead, and also to prevent snag hazards of that. Right now, we’re restricted to areas of the body with small cross-sectional area. So, we’re looking at our fingers, toes, tongue, earlobes, nostrils. Those are the only areas you can use to transmit and sensor. So, the main goal of the system is not to interfere with training at all. So, there aren’t any lights going on when there aren’t any problems. If a trainee’s oxygen saturation level starts dropping, a green light will flash. Then, as their SpO2 level drops even further to dangerous levels, a red light will flash. And then that red light is the indicator to instructors that hey, this person could potentially need some help.

I love this project. The potential to save their lives is readily apparent when I see them wearing it. I don’t think I could ask for a better position as an engineer, a bioengineer. Like, this is what I hoped that I’d be working on.

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