Abstract
Phantom experiments are an important step for testing during the development of new hardware or imaging algorithms for head electrical impedance tomography (EIT) studies. However, due to the sophisticated anatomical geometry and complex resistivity distribution of the human head, constructing an accurate phantom for EIT research remains challenging, especially for skull modelling. In this paper, we designed and fabricated a novel head phantom with anatomically realistic geometry and continuously varying skull resistivity distribution based on 3D printing techniques. The skull model was constructed by simultaneously printing the distinct layers inside the skull with resistivity-controllable printing materials. The entire phantom was composed of saline skin, a 3D-printed skull, saline cerebrospinal fluid (CSF) and 3D-printed brain parenchyma. The validation results demonstrated that the resistivity of the phantom was in good agreement with that of human tissue and was stable over time, and the new phantom performed well in EIT imaging. This paper provides a standardized, efficient and reproducible method for the construction of a head phantom for EIT that could be easily adapted to other conditions for manufacturing head phantoms for brain function research, such as transcranial direct current stimulation (TDCS) and electroencephalography (EEG).
Highlights
Electrical impedance tomography (EIT) seeks to reconstruct the changes in impedance distribution within tissues caused by related physiological and pathological activities; using the data from injecting a set of currents into the body through surface electrodes and measuring the boundary voltages[1]
As the conductive composite materials with acrylonitrile butadiene styrene (ABS) as the matrix are often used in 3D printing field and showed excellent electric properties[25, 26], we attempted to alter the resistivity of ABS/CB composites according to real values of human head tissues by proportionally mixing two types of ABS/CB particles in which we adjusted the content of conductive agent
Given that the head phantom with anatomically realistic geometry and resistivity distribution is needed in studied of brain function, such as transcranial direct current stimulation (TDCS)[29] and electroencephalography (EEG)[30, 31], and the proposed method can be rapidly reproduced using a similar 3D printer and ABS/ CB conductive composites, this study provides an available method for fabricating a more accurate head phantom for brain function studies related to bioelectricity and bio-magnetism
Summary
Electrical impedance tomography (EIT) seeks to reconstruct the changes in impedance distribution within tissues caused by related physiological and pathological activities; using the data from injecting a set of currents into the body through surface electrodes and measuring the boundary voltages[1]. Due to the sophisticated anatomical geometry and complex resistivity distribution of the human head, constructing an accurate phantom for EIT research remains significantly challenging, especially for skull modelling. In 2014, our group fabricated a plaster phantom with anatomically realistic skull shape and spatially varying skull resistivity distribution. In this phantom, after obtaining a 3D skull geometry from computed tomography (CT) reconstruction, we anatomically divided the skull model into eight separated sections (one frontal bone, two sphenoid wing bones, two temporal bones, two parietal bones and one occipital bone), wherein each section had a specific resistivity value that was replicated by changing the ratio of dental-grade plaster to distilled water[14]. The phantom could not produce a continuously varying skull resistivity distribution because it was unable to model the multi-layer structure of skull
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
