Optimal design of electrodes for an electrical impedance tomography based flexible sensor

摘要

A large flexible sensor based on electrical impedance tomography (EIT) is limited in detection area and resolution. It canbe improved by introducing center electrodes. However, the number, the position and the new drive patterns will have agreat impact on the performance of the sensors with large area. Based on the typical 16-electrode flexible sensor, one,two and four center electrodes are introduced in the design to improve the sensors’ resolution, and the new drive patternsfor current injection and voltage measurement are proposed. In evaluating the performance of flexible sensors for thedifferent drive patterns, the detecting resolution and position error are obtained for different numbers of center electrodes.Simulation results show that the flexible sensor with two center electrodes has a satisfactory detection accuracy. And oneof the center electrodes is used for current injection and the other is used for voltage measurement. Mainly consideringthe resolution and position error, the particle swarm optimization (PSO) algorithm is used to optimize the position of thecenter electrodes. The simulation results show that when the center electrodes are positioned at 0.24 from the center, theflexible sensor has a better performance for multi-objective recognition. Compared with the typical 16-electrode flexiblesensor, the detection position error can be reduced by 85.1%. This study provides a new method for finding the suitablenumber and position of the center electrodes for the design of large EIT based flexible sensors.