A novel 3D-printed head phantom with anatomically realistic geometry and continuously varying skull resistivity distribution for electrical impedance tomography

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).

Fundamentals, Recent Advances, and Future Challenges in Bioimpedance Devices for Healthcare Applications

“…In the biomedical field, EIT has been applied to the examination of chest [283], to manage patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) by estimating regional lung ventilation at the bedside [284]. Other areas of application include stroke imaging [285], the characterization of brain tissues [26,286], the monitoring of regional cerebral edema during clinical dehydration treatment [287], the early warning of brain injury during aortic arch replacement operation [288], gesture recognition [289], cancer detection [290][291][292], pediatric intensive care [293], tissue engineering [294], thermal management of hyperthermia [295], or laparoscopic surgery [296]. Another application of EIT is the gating of positronemission tomography (PET) and single-photon emission computed tomography (SPECT) images.…”

Brain Haemorrhage Detection Through SVM Classification of Electrical Impedance Tomography Measurements

“…Naturally, more complex models exist and may be relevant depending on the research question. For example, physical phantom models which model the differing resistivity across the skull are reported in the literature [38,39].…”

Electrical properties, accuracy, and multi-day performance of gelatine phantoms for electrophysiology

“…For brain stimulation situations [22] presented a three layer model for comparing the distribution of brain stimulation currents to a finite element model. For electrical impedance tomography [23] presented a multi-layer 3D printed head phantom, while [24] used a saline water phantom for the same application. Focusing on electrophysiology multi-layer works are more limited, with [25] presenting a three-layered model consisting of a brain (made of urethane resin), skull (made of silicone), and scalp (made of silicone) for testing EEG caps and indicated that realistic scalp electric potentials were generated.…”