FPGAs advance medical imaging

Medical research can only advance as quickly as the technology that supports it. Medical imaging in particular plays a huge role in the entire clinical process—from diagnostics and treatment to surgery and research. In addition to the hurdles medical professionals encounter, “seeing” (in the medical sense) is one of the biggest challenges. Diseases are difficult to spot because they tend to hide deep inside the body. Techniques that enable clinicians to noninvasively see these areas are critical to ensuring progress in this field.

Optical coherence tomography (OCT) is a promising diagnostic tool that could have applications in many different medical fields. The technology takes advantage of the latest computing hardware architectures and is used to create medical instruments that can detect cancer and other conditions in a safe, simple, and effective manner.

 A real-time rendered 3-D images of finger skin shows the fingerprint.

How does OCT work?

This noninvasive imaging technique provides subsurface, cross-sectional images of materials. Interest in OCT technology has grown significantly because it provides much greater resolution than other imaging techniques such as magnetic resonance imaging (MRI) or positron emission tomography (PET). In addition, OCT requires relatively little preparation by medical staff and is safe for patients because it uses low laser outputs without the need for ionizing radiation.

To create images, OCT uses a low-power light source and the corresponding light reflections. It measures light in a way that is similar to how ultrasound machines measure sound. When the light beam is projected into a sample, much of the light is scattered. A small amount reflects as a collimated beam, which can be detected and used to create a very detailed image.

Critical computing elements

Field-programmable gate arrays (FPGAs) enable design flexibility, helping designers explore new ideas and reduce risk in the system development process. This capability is important in the medical space because it is critical to get to market quickly. Traditionally, demonstrating hardware-based processing required a custom application-specific integrated circuit (ASIC), but ASIC development is expensive and functionality is fixed. 

FPGAs are reconfigurable through software. This advantage enables a designer to save development time by demonstrating hardware-based processing while preserving the option of reprogramming the FPGA to accommodate modifications that are required after initial specification. Although FPGA board designs can be complex and modular, off-the-shelf FPGA boards provide hardware to build around with infrastructure components for I/O connectivity, bus interfacing, and DRAM communication. Developing these components in-house can be time consuming and distracting. 

FPGAs have rapidly grown in popularity for medical applications. With regard to medical imaging, FPGAs are primarily used in detection and image construction. The detection application involves embedded systems, with real-time performance requirements and significant hardware interface challenges. Image reconstruction, on the other hand, is similar to a high-performance computing problem.

To read the entire article, which originally appeared at sibling site Medical Electronics Design, click here.

About the authors

Shelley Gretlein is director of software product marketing, and Casey Weltzin is a product manager for embedded software; both are at National Instruments (Austin, TX).

Editor's note: Liked this? Want more?

If you are interested in "medical-design" issues including transducers and interfaces; processors; software; and system design, then go to the Medical Designline home page here for the latest in design, technology, trends, products, and news. Also, sign up for our weekly Medical Designline Newsletter here.