Gone are the days of visiting a doctor's or dentist's office to have X-rays taken and being told to wait hours or even days to have results returned from a lab. A growing and aging population knows more about their healthcare options than ever before. For example, it is not uncommon for patients to request several medical-imaging scans or scans at regular intervals to ensure their peace of mind. Add to this that healthcare spending is soaring while insurance coverage is declining. This increase in out-of-pocket costs fuels patient demand for better value and higher expectations in response time and quality of care.

The healthcare industry today must work under tight budgets while simultaneously increasing productivity. Inefficient practices and outdated equipment can push facilities into financial distress. A solution is the move towards digitized or “paperless” medical information using electronic media that can be accessed from many locations. Medical facilities are implementing internal networks that connect X-ray, CT scan, and PET-scan equipment so diagnostic data and patient information can be fed and accessed over a network for almost instant access.

Also, bedside monitors analyze, document, and display patients' vital signs while transmitting the data to a central location where healthcare personnel can see it without walking to each patient's bed. Medical-equipment suppliers are developing complete systems that include the diagnostic or monitoring equipment, data-storage servers, and interface software. Networked equipment let fewer staff monitor more patients. This boosts productivity and helps facilitate early diagnosis and treatment.

PLDs foster paperless hospitals

A key driver to going paperless is innovative technology such as programmable logic devices (PLDs), a programmable semiconductor. More of today's medical equipment contains semiconductors, a trend that is on the increase. Medical manufacturers are using more PLDs than other devices because they provide a powerful alternative to application-specific integrated circuits (ASICs) and application specific signal processors (ASSPs). PLDs eliminate the up-front, non-recurring engineering costs and minimum-order quantities associated with ASICs.

And because PLDs can be reprogrammed, they eliminate costly risks associated with multiple silicon iterations during the design cycle. When compared to ASSPs, PLDs provide design flexibility and board-integration capabilities that can give manufacturers a competitive advantage. In addition, units can be updated in the field as standards evolve or requirements change. And a common hardware platform lets designers create differentiated systems that support a variety of feature-sets with one basic design. This helps cut manufacturing costs. Last but not least, PLDs have a long lifecycle that protects customers against product obsolescence, a critical consideration for medical designs because of their long product cycles.

PLDs are particularly useful in the area of diagnostic imaging. Here, shapes such as ligaments, organs, and bones are initially captured in 1D but need translation into 2D or 3D formats. Captured images thus require compensation and filtering through signal-processing techniques. This has been done in one, or sometimes up to 20, different and perhaps costly data-acquisition cards. Filtered data travels to a data-consolidation card for buffering and data alignment. In CT and PET scanners, where detectors rotate around the body, data is serialized and sent across a slip-ring electromechanical subassembly, with collected data going to an image-processing card. It performs heavy-duty filtering and algorithm-intensive image reconstruction. Healthcare personnel can then see the final image on an attached LCD or thin-film-transistor monitor. The image can also be compressed and transmitted across a network for storage or viewing in a remote location.

In the design of equipment containing PLDs, it is necessary to consider several factors including portability, image resolution, 2D versus 3D imaging, and the number of required channels. Each parameter affects PLD selection. For low-cost data-acquisition cards, a type of PLD called a field programmable gate array (FPGA) — such as our company's Cyclone III — make a good candidate. They provide plenty of digital signal processing multipliers to implement image compensation and filtering.

FPGAs for portable equipment

Other FPGAs also work well in a range of applications. For example, the use of a soft-core processor-development environment, such as the Nios II embedded processor, lets designers quickly and efficiently assemble elements to drive a wide range of LCD-panel configurations. Functions such as timing control and interfacing to external memory devices can be implemented as simple building blocks in the FPGA.

An increasing trend towards portable imaging equipment has developed because of a potentially wider customer base. However, space-constrained equipment requires low-cost semiconductors with low-power consumption and a small form factor. Low-cost FPGAs can be a good solution. Some devices provide up to 120,000 logic elements with 288 digital signal processor (DSP) multipliers and 4 Mbits of embedded memory while consuming less than 200 mW of standby power. These FPGAs come as small as 8 × 8 mm.

Mid-range FPGAs such as the Arria GX, or high-performance FPGAs such as the Stratix IV and HardCopy IV are well-suited for data consolidation and data-processing cards. They give engineers flexibility, performance, and design resources for the highest level of system integration and bandwidth. This range of FPGAs provides dedicated high-performance DSP blocks and a variety of embedded memory blocks to perform heavy-duty image-processing functions. These include scaling, image recreation, and fast-Fourier-transform algorithms. The high-performance of these FPGAs also let suppliers combine equipment, for example, combined CT-PET machines.

Versions of these semiconductors also feature 1.25 to 8.5 Gbps serial transceivers to transport high-speed data across slip rings and backplanes. For example, FPGAs with these transceivers can connect scanning equipment to a PC-based program using the widely adopted PCI Express (PCIe) protocol. The tranceivers do not eliminate the slip rings. Rather, the tranceivers allow pushing data across at the high speeds required by the slip rings or backplanes. Raw data coming from an ultrasound transducer or magnetic resonance imaging scanner can be pre-formatted for easy communication to the PC-based analysis and display software.