Studying the surface electrode switching of a sixteen electrode EIT system using a LabVIEW-based electrode switching module (LV-ESM)

Surface electrodes are essentially required to be switched in a sequential fashion in electrical impedance tomography (EIT) system for current injection and voltage measurement in particular current pattern. Analog multiplexers or other electronic switches are generally used to switch the driving and sensing electrodes attached to the object boundary for current-voltage data collection. Analog multiplexers used for electrode switching are operated by the digital data generated by an electronic hardware-software module (HSM) working within the EIT electronics. Lab VIEW based National Instrumentation Hardware are found very suitable hardware-software module for digital and analog or mixed data acquisition and signal processing which can be suitably used for digital signal generation and electronic switching of EIT surface electrodes. In this direction a LabVIEW based electrode switching module (LV-ESM) is developed for a sixteen electrode EIT system and surface electrodes switching is studied with opposite and neighbouring current injection pattern. LV-ESM is tested and evaluated with sixteen electrode EIT phantoms and results demonstrated that the LV-ESM accurately switches the surface electrodes for boundary data collection.