Electrical impedance imaging system using FPGAs for flexibility and interoperability

BioMedical Engineering OnLine

Harsh Sohal¹  Hun Wi¹  Alistair Lee McEwan²  Eung Je Woo¹  Tong In Oh¹ 

[1] Department of Biomedical Engineering and Impedance Imaging Research Center, Kyung Hee University, 446-701 Yongin, Korea

[2] The School of Electrical and Information Engineering, The University of Sydney, NSW2006, Sydney, Australia

关键词: Fast multi-frequency imaging;    Biosignal-gated imaging;    Application specific integrated circuit (ASIC);    Field programmable gate array (FPGA);    Electrical impedance tomography (EIT);   

Others  :  1084457
DOI  :  10.1186/1475-925X-13-126

 received in 2013-12-04, accepted in 2014-08-25,  发布年份 2014

【 摘 要 】

Background

Modern EIT systems require simultaneously operating multiple functions for flexibility, interoperability, and clinical applicability. To implement versatile functions, expandable design and implementation tools are needed. On the other hand, it is necessary to develop an ASIC-based EIT system to maximize its performance. Since the ASIC design is expensive and unchangeable, we can use FPGAs as a prior step to the digital ASIC design and carefully classify which functions should be included in the ASIC. In this paper, we describe the details of the FPGA design adopted in the KHU Mark2.5 EIT system.

Methods

We classified all functions of the KHU Mark2.5 EIT system into two categories. One is the control and processing of current injection and voltage measurement. The other includes the collection and management of the multi-channel data with timing controls for internal and external interconnections. We describe the implementation of these functions in two kinds of FPGAs called the impedance measurement module (IMM) FPGA and the intra-network controller FPGA.

Results

We present functional and timing simulations of the key functions in the FPGAs. From phantom and animal imaging experiments, we show that multiple functions of the system are successfully implemented in the FPGAs. As examples, we demonstrate fast multi-frequency imaging and ECG-gated imaging.

Conclusion

Given an analog design of a parallel EIT system, it is important to optimize its digital design to minimize systematic artifacts and maximize performance. This paper described technical details of the FPGA-based fully parallel EIT system called the KHU Mark2.5 with numerous functions needed for clinical applications. Two kinds of FPGAs described in this paper can be used as a basis for future EIT digital ASIC designs for better application-specific human interface as well as hardware performance.

【 授权许可】

   
2014 Sohal et al.; licensee BioMed Central Ltd.

【 图 表 】

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