• telemedicine
• Impedance
• tomography

The thesis concerns the fasibility about the electrical impedance tomography (EIT) technique implemented through a device for health monitoring, the BodyGateWay (BGW), developed by STMicroelectronics at Agrate Brianza (MB).
EIT, in clinical practice, is used to provide tomographic images in a non-invasive way, by electrical measurements made from a series of electrodes on the surface of the region of interest. Nowadays the most promising applications of EIT are monitoring of patients with complications related to the respiratory system and surgery assistance for intra-surgical imaging.
BGW is a wireless wearable device for continuous remote monitoring of ECG and bio-impedance signals. It is equipped with an optimized front-end and low-power system management. The challenge of being able to implement additional functionality without drastically changing the architecture of the device have pushed the development of this work.
The first phase of the project involved the analysis of algorithms and mathematical structures developed in MATLAB environment within the EIDORS project for the solution of direct and inverse problem related to EIT. Optimal parameters, regarding methods of acquisition and matrices for conditioning of ill-posed problem (a-priori information about conductivity distribution, noise, geometrical factors) have been identified. These operations were performed through COMSOL simulation on complex anatomical models, demonstrating the feasibility of EIT image techniques reconstruction in ideal case.
The next stage involved hardware and software design of an electronic device, to be interfaced to the BGW, for automatic selection of electrodes pairs for current injection and bio-impedance acquisition. The whole system was tested on a phantom which replicated the typical conductivity of the tissues of the thoracic region.
The results led to a further optimization obtaining image quality comparable to those presented in literature.
The final tests, conducted on healthy subjects, have produced promising preliminary results, highlighting the potential offered by the implementation of this imaging methodology in a low-power device designed for continuous patient monitoring.