Suitability of a PXI platform for an electrical impedance tomography system

Abstract

There are many different electrical impedance tomography (EIT) systems which are either non-commercial (in-house products) or commercial products. However, these systems are usually designed for specific applications and therefore the functionality of the systems might be limited. Nowadays there are commercially available many low-cost, efficient and accurate multifunctional components for data acquisition and signal processing. Therefore, it should be possible to construct an EIT system which is mainly built from commercially available components. The main goal of this work was to study the performance of a PXI-based EIT systemPCI eXtension for Instrumentation.. In this work, a PXI-based EIT system with 16 independent current injection channels and 80 independent measurement channels was constructed and tested. The results indicate that an EIT system can be constructed using a PXI platform which decreases the construction time of the system. Moreover, the system is efficient, accurate, modular, and it is not limited to any predetermined measurement protocols.

FPGA-Based Voltage and Current Dual Drive System for High Frame Rate Electrical Impedance Tomography

“…The EIT system presented here uses a PXI platform similar to the previously reported KIT4 [22]. There are, however, several differences between the EIT system presented here and the KIT4 [22].…”

“…For the AFE test, a 545Ω (equivalent) resistor was connected between source channel and current to voltage converter's virtual ground. Use of discrete loads is a standardized approach typically used to evaluate EIT systems [22], [24], [28]. The source and sink PGA gains were set to 2.52 each.…”

“…The NI hardware and software modules are inherently compatible with each other through generations of hardware and software advancements, this makes them a suitable choice for developing an EIT system that can be upgraded with newer hardware modules that work with the existing code. The suitability of PXI platform for EIT has been previously reported [22]. The NI hardware includes PXI chassis, Field Programmable Gate Arrays (FPGA) for deterministic signal acquisition and spectral characterization, and additional hardware modules for timing and synchronization, signal generation, and ADC.…”

Dynamic Link Library and Signal Conditioning System for Electrical Impedance Tomography Virtual Instrumentation

“…For a discretized volume this integral corresponds to the sensitivity coefficient matrix S. A number of researchers have addressed the linearized EIT image reconstruction problem using quantitative and qualitative methods. This work uses the qualitative weighted sensitivity backprojection method where the reconstructed pixel grey levels are obtained by (12): (12) where υ p is the perturbation voltage and υ ref is the reference value. In simple terms, this means that although the backprojection method does not yield the exact impedance values throughout the volume, the reconstructed images represent the changes in impedance values within the bounded volume.…”

“…The usefulness of VI for diverse applications is now widely addressed for a diverse number of applications ranging from signal processing [10] to control [11]. One of the advantages is that a virtual instrument can be constructed using commercial software and off-the-shelf data acquisition systems [12] as well as software and hardware designed for any specific application.…”