Please assess the completion status of the following clinical trial:

Trial Title: NATO Litter: Fluid Immersion System (FIS) Versus Traditional Mattress for Pressure Dispersion

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: HEALTH_SERVICES_RESEARCH
- Time Perspective: None
- Masking: NONE
- Phase: None
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* Adults over the age of 18 years with lawful access to Travis Air Force Base (AFB)~Exclusion Criteria:~* Orthopedic or neurological conditions that prevent a subject from lying flat (supine) without any pillows for head, neck, or lumbar support~* Medical conditions (such as an uncontrollable tremor or twitch) that prevent a subject from staying still for the required periods of time (20 minute increments).~* Pregnancy~* Inability to ambulate unassisted, unstable gate (presenting increased fall risk)~* Extremity prosthetics (hand/arm or foot/leg)~* Height greater than 72 inches (6 feet) - exceeds length of the litter \& mattress surfaces~* Body weight greater than 300 lbs~* Subjects who find it difficult, uncomfortable or impossible to remain still for the necessary study time durations (20 minute increments) on the relatively narrow litter surfaces will be removed from the study.~* Subject does not speak or understand the English language

- Gender: ALL
- Minimum Age: 19 Years
- Maximum Age: None
- Healthy Volunteers: t

Study Arms:
- NATO WELP combination (Type: EXPERIMENTAL): Subjects will be their own control and have repeated measurements to compare baseline and supine transcutaneous oxygenation levels and interface pressures on NATO litter and WELP mattress combination
- NATO FIS combination (Type: EXPERIMENTAL): Subjects will be their own control and have repeated measurements to compare baseline and supine transcutaneous oxygenation levels and interface pressures on NATO litter and Fluid Immersion System (FIS) mattress combination
- RAVEN WELP combination (Type: EXPERIMENTAL): Subjects will be their own control and have repeated measurements to compare baseline and supine transcutaneous oxygenation levels and interface pressures on Raven 90C litter and WELP mattress combination
- RAVEN FIS combination (Type: EXPERIMENTAL): Subjects will be their own control and have repeated measurements to compare baseline and supine transcutaneous oxygenation levels and interface pressures on Raven 90C litter and Fluid Immersion System (FIS) mattress combination

Based on this trial design, predict the completion outcome and termination type (if applicable).