Medical Device Link.

OEMs are being driven to deliver this continually improving equipment by four key factors: the need to contain costs, a decreasing time to market, the advantages of improved resolution, and a shortage of engineers. These interrelated market factors operate in the context of an increasingly global customer base.

OEMs are addressing these factors chiefly through rapid deployment of the latest technology and an increased dependence on outsourcing. They have always closely tracked technological advances and have traditionally used them to improve their products and, ultimately, reduce costs. A newer response to this challenge is their recourse to the extended engineering workforce and life-cycle management capabilities that are available through an experienced outsourcing partner.

Electronics designers for radiology equipment must investigate system architectural changes to keep pace with market trends. Related medical equipment, such as hard-copy output stations, data storage devices, and picture archiving and communication systems, is also subject to these pressures. Improving functionality is the natural starting point for architectural innovation, followed by the need for enhanced performance. Increasing global competition means OEMs must innovate under extremely short development schedules and intense containment restrictions, both in unit product costs and life-cycle development expenses. One answer is to move from proprietary solutions to standards-based designs. Although this approach initially presents new challenges, it can be effective in getting products to market quickly and keeping costs under control.

Another example would be the process required to add a digital imaging and communications in medicine (DICOM) interface to a radiology modality. In the past several years, the medical market has come to expect a DICOM port on many radiology information system modalities, thereby providing a standards-based connectivity scheme. However, this imposes additional processing, storage, connectivity, and data flow requirements—without sacrificing any performance in the baseline system. Rather than taking on this design problem internally, OEMs can work with a DICOM-focused partner company to provide this increasingly common interface. The OEM hires experts to handle the DICOM-related issues, allowing it to focus its resources on strategic innovation within the modality, resulting in better use of resources and a reduced time to market.

Figure 1. A schematic representation of an imaging system with a DICOM interface.

The medical imaging system in Figure 1 requires a DICOM interface. The modality acquires the data and displays it on a console for viewing by a technician. The DICOM interface box provides connectivity between the modality and the hospital information system network. Because processing power and connectivity are important attributes, working with a partner that also has expertise in central processing unit (cpu) design and networking technologies is a significant advantage. Outside expertise can help OEMs get the most out of the equipment design, for example, by configuring state-of-the-art cpus to meet software image-processing requirements while designing the latest network interface 10/100/ 1000BaseT (gigabit) Ethernet expansion capabilities right on the platform.

To see this partnership at work, consider the development of an advanced MR system. As MR systems increase in speed, so do their potential applications. For example, while once capturing static images on film, today's functional MR applications highlight organs in operation. To make this leap in technology, a change in a fundamental design parameter, such as speed, often has systemwide implications. At the board level, even a simple change like the move to gigabit Ethernet places throughput demands on the local PCI bus that can ultimately affect image-capture performance.

A partner can bring to the table an understanding of end-product requirements, system performance, and the latest computer technologies to help the OEM manage these requirements during the conceptual phase, through performance evaluation, and ultimately through product deployment. Throughout the development process (often years for medical equipment), the OEM is freed to focus on applications and other design attributes that distinguish its product in the market. Meanwhile, its partner organization is managing all issues related to the product infrastructure over its life cycle, such as technology seminars, detailed design and modeling, prototypes, product integration, and test.

Figure 2. Using a CompactPCI architecture can solve system-level design issues by providing 250-plus pins on three connectors.

A good example of this kind of design process is the utilization of a CompactPCI system to solve a systems-level issue (see Figure 2). In this example, a dedicated chest computed-radiography system uses CompactPCI to provide the electronics platform. In addition to processing requirements, a typical medical modality has demanding I/O data requirements, particularly in the areas of data acquisition and transmission. Although VME is alive and well, CompactPCI has advantages. Because most high-speed bus traffic has gravitated to add-in buses, a significant advantage of CompactPCI in a market that does not yet require high availability (defined as 99.999% availability, the equivalent of five minutes or less of downtime per year, both planned and unplanned) is the 250-plus pins of user I/O available on three connectors. For example, this additional I/O can be used for rear connections for all I/O on two PMC (PCI mezzanine card) modules, allowing add-in I/O modules that tailor the system to exact interface requirements. There are even adequate pins to implement a user-defined imaging bus and handle module I/O, opening up architectural alternatives even further. The user, therefore, can develop an industry-standard PMC that provides the custom I/O interface, with confidence that the PMC card can be utilized on future (or other) systems.

Because medical equipment lifetimes are relatively long, an OEM may wish to provide a technology refresh of the electronics platform to add new features while retaining key architectural elements of the system. As functionality of medical devices advances, there will come a point at which reaching levels of high availability (99.999% or 5-nines availability) will be a crucial aspect of the equipment's performance, especially when complex and expensive combined-modality systems (for example, computed tomography) require constant use to provide payback. In all these cases, if the platform selection has been carefully done with an eye on standards and future product road maps, integration of a new technology to replace or supplant the existing system can be planned as a natural evolution.

Regulatory agencies play a part in the relationship between OEM and vendor. For example, manufacturers of medical equipment are subject to new quality system standards adopted by FDA in 1997 and enforced since 1998. The requirements applicable depend on the end product. They can include design controls on hardware and software developed in-house. An outsourced product is likely to be subject to a different portion of the quality system regulation and have a purchase specification as well as other requirements. An end-device manufacturer must carefully evaluate the trade-offs involved and work with vendors to ensure that requirements in the regulations are met.

No matter what choices are made during the design cycle, medical equipment manufacturers are required to control product changes after the design has been transferred to production. All changes may be subject to verification and validation. Depending on the extent of the changes involved, this cycle can become time-consuming and expensive. Given the very high level of product turnover in the electronics industry, an electronics vendor may be better suited to managing this part of the process. Judiciously selecting platforms and technologies through partnerships, and then using in-house designs when appropriate, can minimize the impact of design changes.