MEDICAL EQUIPMENT & DEVICES  ANALOG DEVICES


High performance data converters for medical imaging systems


Ya Liu, Jian Li, San-Hwa Chee and Marvin Macairan, all with Analog Devices, highlight that there has been a shift in data centre and telecom power system design.


T


he discovery of X-radiation by Wilhelm Conrad Röntgen in 1895 earned him the 


 imaging. Since then it has developed into an  designates diverse techniques for non-invasive    This article considers the main types of modern medical imaging systems that utilise fundamentally different physical principles and processing techniques but have one thing in common - an analogue data acquisition front end serving for signal  into a digital domain.   its performance that has a crucial impact on the resulting image quality of the complete system. Its    main subject of this article. The data converter constitutes the most demanding challenges imposed by medical imaging on the electronics design in terms of required


 noise. This article discusses these design challenges in the context of different imaging modalities and   optimum levels.


DIGITAL RADIOGRAPHY  principles common to all conventional absorption- based radiography systems. The X-rays passing through the body are attenuated by tissues of different radiographic opacity and projected on a  in Figure 1.


The detector converts the X-ray photons into electrical charges that are proportional to the energy of the incident particles. The resulting  a digital domain to produce an accurate digital representation of the X-ray image. The quality of this image depends on the signal sampling in the spatial and intensity dimensions. 


 detector and the update rate for real-time  millions of pixels and typical update rates as high


as 25fps to 30fps employ channel multiplexing and    


 X-ray photons absorbed in a given pixel over a    


 of the system to faithfully represent the anatomic   70dB up to 100dB depending on the type of the     


COMPUTED TOMOGRAPHY   it is based on an arc-shaped detector system  utilises more sophisticated processing techniques to


Figure 1: Digital X-ray detector signal chain 18 October 2024 Irish Manufacturing www.irish-manufacturing.com


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