Electrical impedance tomography (EIT) is a non-invasive, real-time, continuous imaging technique that has multiple applications in health care. EIT is a realizable technique for radiation-free medical imaging ranging from real-time monitoring of bone fracture repair to lung functioning. This work explores the prospect of printing a wearable bioimpedance sensor on textiles for EIT imaging. Screen printing and stencil printing were applied to fabricate the sensor on the textile substrate and the imaging was carried out with the worn sensor on the human body. The first part of this work focuses on developing a flexible textile sensor in the form of a bracelet to obtain cross-sectional images of the forearm that unravel bone features like shape, size and position. However, body parts such as the thorax have added complexities due to their constantly varying perimeter and uneven shape. It is a significant prerequisite for the wearable sensors to apply to dynamic body parts where irregular shape and continuous volume variations occur. The second part of the paper therefore addresses the fabrication and testing of a stretchable textile-based sensor to address such instances of body dynamicity. The proposed stretchable sensor, worn on the thorax, demonstrates the feasibility of imaging such an uneven and dynamic body part. Although the EIT images are inherently attributed to low resolution, this work shows the prospect of wearable imaging applications in health monitoring. Apart from demonstrating the printed sensor for EIT imaging, this paper shows the image rendering quality dependency over the frequency of the signal and the number of electrodes. This work could initiate further research on wearable EIT based health monitoring devices for real-life scenarios.

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Electrical Impedance Tomography (EIT) is a non-invasive, non-ionizing, and inexpensive imaging modality that is used to image the conductivity distribution inside the subject under test. EIT is an emerging imaging technique that has the potential to be used in a variety of (bio)medical applications. A technology that is easy to integrate into a small portable device and also easy to setup. In this work a custom made impedance analyzer is used as a measurement device. The working principle is based on the different conductivity distributions of the material under test, this due to inhomogeneous bioelectrical properties. However there is one major downside of this technique, the reconstruction problem of EIT is severely ill-posed. This means that the definition of a correct model is essential. Because of this ill-posed condition, a comparison of different models is done. In this work, an in depth study is performed to achieve the most optimal way of solving the inverse problem, which leads to noise suppression and reproducible results. This technology, integrated in a lab-on-chip for monitoring cellular growth, is based on a spatial reconstructed imaging technique using electrical impedance tomography.