In-water electrical impedance tomography: EIT and the sea

Area of Science:

• Biomedical Engineering
• Marine Biology
• Diving Physiology

Background:

• Electrical impedance tomography (EIT) offers valuable functional ventilation data in terrestrial mammals.
• Applying EIT to marine mammals and divers is desirable for performance, safety, and behavioral research.
• The high conductivity of seawater poses a significant challenge for in-water EIT.

Purpose of the Study:

• To investigate the feasibility of using EIT in aquatic environments.
• To develop and evaluate techniques for overcoming the challenges of in-water EIT.
• To demonstrate the utility of EIT for monitoring lung ventilation in marine subjects and divers.

Main Methods:

• Modeling the electrical properties of the in-water EIT system.
• Developing and assessing image reconstruction algorithms for aquatic conditions.
• Designing and testing custom EIT belts with neoprene insulation to mitigate current leakage.

Main Results:

• Reasonable EIT images can be obtained when the water layer thickness is less than 2% of the body radius.
• Custom-designed insulating EIT belts effectively minimize current leakage in water.
• Successful underwater EIT recordings were achieved in both human divers and dolphins.

Conclusions:

• In-water Electrical Impedance Tomography is a feasible technique with the implementation of specialized methods.
• This advancement opens new avenues for studying lung function in marine mammals and underwater human physiology.
• The developed techniques support enhanced diver safety and provide novel insights into marine animal respiratory dynamics.