Medical Device Link.

While the medical sector in general is experiencing steady growth, portable medical equipment is a segment of the industry that is booming exponentially. Small, handheld devices are improving healthcare for millions of people in hospitals, doctors’ offices, homes, and emergency situations.

From diagnostic equipment that informs and monitoring devices that keep tabs on existing conditions, to equipment that can actually perform lifesaving treatment, a host of electronic medical devices have enhanced the quality of life for people worldwide. Coming years will continue to bring many new, innovative products for medical applications that will vastly improve the delivery and effectiveness of healthcare.

Medical equipment manufacturers are now pioneering the concept of these take-everywhere diagnostic tools to enable medical practitioners to make faster and more-accurate clinical decisions at the point of care. Ultraportable point-of-care units, such as portable ultrasound systems, require low power and high performance in a very small form factor. Key design considerations continue to focus on low power consumption, high efficiency driven by extended battery life, and high precision for fast response time driven by the user’s need to quickly know the status of the patient’s health.

Until recently, the convenience of portability has required manufacturers to sacrifice image quality, limiting the medical diagnoses that could be made with portable ultrasound equipment. In addition, there have been few options available among the standards-based embedded computing platforms thatcould adequately meet the requirements. The platforms were not small enough to encompass the board and cooling products, lacked the right mix of integrated features, or failed to provide a seamless migration for next-generation product revisions.

The COM Evolution

Computer-on-modules (COMs) have come into their own as an option for a broad range of medical electronic applications where they fit mechanically, economically, and functionally. Today’s COM products can drive faster time to market, reduce development cost, and minimize design risk, as well as simplify future upgrade paths and scalability, and increase application longevity. But the medical electronics industry is moving fast, following a path not unlike consumer electronics, and portable is now evolving to ultraportable. COMs have answered early portability requirements with performance, flexibility of design, and easy customization. A broad range of COM-based products is now on the market, and micro and nano options have extended the definition of the word portable.

ETX (Embedded Technology eXtended)—an open standard from Kontron that became the de facto standard for PCI- and ICA-based COMs—was the beginning of the COM evolution. This original ETX standard offered a number of advantages, including full PC functionality, minimum engineering and adoption cost, reliable connectors, and extremely slim design. It also offered simple upgradability and scalability, allowing the integration of embedded computing technology into next-generation applications such as advanced medical imaging.

It was upgraded to ETX 3.0 to bring in two serial advanced technology assessment (SATA) connectors on the top side of the module while keeping the same pin-out for the connectors. This upgrade ensured that no carrier board redesign would be required to allow use of the new SATA hard drive. As PCI Express began to deliver more-advanced technologies, ETX could not be modified and still retain the same pin-out, so a new COM standard was required.

COM Express was the next to be developed. It is a proven PICMG open specification, originally sponsored by Kontron, Intel, PFU, and RadiSys. The COM Express standard provides the advantages of a modular, off-the-shelf design and implementation approach, with benefits including reduced cost, improved quality, standard architecture, scalability, and flexibility. COM Express is simply the evolution of the already successful de facto ETX standard for PCI- and ISA-based COMs that was developed by Kontron in early 2000. It includes specifications for small-form-factor modules to satisfy the [high-performance] requirements of the embedded industry, including medical electronics. For embedded applications, higher performance comes from selecting the appropriate power and performance to provide the optimal balance. Using the Atom and Core 2 Duo as examples, the power envelope for an embedded application is a system TDP of 45 W. This is paired with a low-profile passive or active cooling system and appropriately designed carrier board.

COM Express modules provide a smooth transition from PCI, ISA, and IDE (legacy technology) to PCI Express, SATA, and others. Additionally, the support of PCI Express Graphics (PEG) rather than older AGP graphics has greatly improved medical imaging. Support for gigabit Ethernet and USB 2.0 (advanced communications technologies) allows medical personnel to view images in real time. While serial DVO and LVDS capabilities eliminate the bottleneck in the transmission of data to the user or in the initial development of the product, COM Express enables portability as well. Much of the hardware development, design, and testing is done by the module manufacturer, allowing the medical application developer to focus on the software and special features of the tool itself.

COM Express modules can support large (e.g., a 2-GHz CPU and up to 8 GB system memory) processor and memory requirements. Up to 440 pins of connectivity are available between the CPU modules and the carrier board. Legacy buses such as PCI, parallel ATA, LPC, HD Audio (or AC’97) can be supported as well as new high-speed serial interconnects such as PCI Express, SATA, or SAS and gigabit Ethernet. To enhance interoperability between COM Express modules and carrier boards, five common signaling configurations (pin-out types) have been defined to ease system integration. Some pin-out types require only a single 220-pin connector, and others require both 220-pin connectors to supply all of the defined signaling.

Customization of COMs

In general, COMs are well suited for designs that demand a lot of application-specific customization and can afford to use two PCBs (a module plus a custom carrier board). Modules themselves are a standard off-the-shelf product within the module core. Customization is designed into the module’s carrier board and can last for generations with various CPU cores, for example, swapping out one for the next. If the design plan includes multiple variations of a product within the same generation, perhaps with different performance capabilities, designers can use the same carrier board for those variations by just changing the module within it. And medical applications, with their tremendous range of function and purpose, are an excellent match for this technology.

The end result—and a big advantage for medical electronics engineers—is that COMs work well for devices that not only require scalability from generation to generation, but also within a single generation. When an application requires something special that is not typically found in a standard motherboard, those computing issues can be customized into a COM’s accompanying carrier board, which allows for easy transitions to future generations. For example, an imaging application that in the past has run on a cart now needs to be developed on a smaller scale. Its carrier board has been customized to talk to the components that run the actual image capture, and now designers want to shrink down that entire process into a smaller device.

Medical applications require very long life cycles—10 years is typical. Commercial computer boards, as opposed to COMs or embedded SBCs and motherboards, simply don’t support such a long product life cycle. They change every nine months or so, and although they may be inexpensive, they cannot be customized in the same powerful way that a module can be.

Designers know that the CPU, chip set, and other existing components have optimal functions; they can keep using the COM they are familiar with and modify the carrier board to accommodate a new, smaller size. Because core elements remain the same, designers can avoid respinning drivers for change of hardware. Computing function is simply ported over to the smaller design.

Smaller COMs, Smaller Devices

Marketplace demands require further downsizing of the existing COM Express form factor while maintaining its feature set. For new and more-portable medical applications, designers now have additional options available within the COMs standard, including the compact microETXexpress and ultrasmall form factor nanoETXexpress families of COM Express–compatible modules. The primary differences between these COM-based modules are the overall physical size and the performance capabilities supported by each.

The compact microETXexpress form factor measures just 95 × 95 mm and closely follows the already mainstream PICMG COM.0 COM Express specification. Interchangeable with existing COM Express designs, microETXexpress is technically identical to COM Express with respect to the pin-out type 2 definition and connector location. The only significant difference is its smaller board size and the addition of one extra mounting hole in the top right corner.

The important trend here is the reduction in the size of devices, as well as the reduction in the size of components that can be designed in. Size is typically not a limitation with a motherboard, which can easily have all of the components it needs and then some. Ports may even go unused, but that will not affect performance or function in any way. Modules are more limited by physical constraints; all of its different components must fit within the footprint of the module itself, and the connecting pins defined on the bottom must connect appropriately to the processor and controller signals.

COM modules can be used for applications that previously faced barriers due to size, performance issues, or power consumption. A future application could be a miniultrasound machine—perhaps as small as a brick that would fit into the pocket of a lab coat—that could wirelessly transmit images to a standard PC for remote diagnosis.

Engineering BeyondLow Power

COM Express addresses the requirements of mobile medical applications. Designers have multiple power-down options, such as BIOS controlled or core voltage controlled, with switch on-off functionalities and the use of “on device” power-saving capabilities. COM Express modules also support on-module suspend modes with s-mode, wake-on-LAN, and fast-boot options.

In fact, engineering beyond low power is a critical design element for ultraportable medical applications. Power efficiency is essential and may require software-enabled customization. Power needs to stop and start to deliver extended battery life, yet the device needs to always be at the ready for patient service or information exchange. Smart battery technology can recharge certain portions of the device while keeping others in standby mode, resuming full power and function on demand.

Smart battery technology begins with reference designs such as Mobile Application platform for Rechargeable Systems (MARS), which complement the range of COM products and offer a means of putting smart battery capabilities on a customized carrier board. MARS is a modular reference design that adds 2-SMART batteries to the customized carrier board working in conjunction with the COM. Designers have a quick evaluation platform and reference design, which is open for unlimited designing use and provides a guideline for right-sized engineering.

Because the silicon platform and operating system function independently, using the MARS modular approach allows designers to choose only the blocks of functionality required for a particular design. Medical electronics engineers can leverage a number of options to optimize for mobile applications, incorporating uninterruptible power supplies (UPS), in-operation battery recharging, and a wide range of input voltage (from 5 to 20 V dc). MARS allows ATX functionality, offering a single voltage input and ATX voltage output, as well as support for suspend modes S0 through S5. Surge and short-circuit protection and monitoring also improve the overall use of the device and its applicability for ultraportable applications.

How does it work? A SMART battery system uses an input buck-boost convertor to automatically adapt the voltage for various power supplies. A dual buck-boost convertor provides an ATX conforming voltage generator, and a standard buck-boost convertor acts as an extended input voltage convertor for dual batteries to charge. Its best fit is in customizing modules based on ETX, COM Express (basic FF pin-out type 2), and microETXexpress (compatible to COM Express pin-out type 2).

Designers can use the MARS reference design starter kit for quick evaluation and simplified design-in. Applications that previously faced barriers due to size, performance issues, or power-consumption limitations can now be developed using a standard COM implementation with value-added power management features such as MARS.For example, a medical device can acquire data while another portion of the device is at rest or transmitting data. Such capability can tap sophisticated power management to significantly improve the speed and quality of patient care. They provide seamless, uninterrupted usability and data collection with little or no manual management of the devices by healthcare practitioners.

Improved Graphics

COM Express modules offer many advantages for portable devices. They are broadly deployed and deliver the right balance of size, power, and functionality. However, with more-demanding video applications such as high-definition TV and 3-D graphics, sharing the CPU module’s system memory for processing can create a bottleneck. Medical imaging devices have similar demands, and medical electronics engineers must design-in the capability for high-resolution data capture and speedy image processing. Often, even the CPU itself might not be sufficient to effectively manage intense graphics processes. As a result, there is a trend toward shifting those functions to a graphics processing unit (GPU.)

GPUs are dedicated rendering devices—very efficient at managing and displaying high-resolution graphic images—that can live on top of a video card or be fully integrated into the motherboard. There has been no COM Express module developed for a GPU, and designers have relied on dedicated standard graphics cards integrated into the COMs’ custom carrier board. Designers face more complex mechanics in this scenario, including working with high-profile components, fan requirements, and output connectors that are not suitable for a COM design. Additionally, commercial graphics cards did not meet the long life cycles needed for embedded applications.

That has changed within the last two years with the introduction of the universal graphics modules standard and compliant products. Designers now have access to UGMs as a standardized COM graphics solution. UGM is a dedicated graphics module specifically for embedded applications that offers significant improvements and benefits to the COMs’ management of graphics, including a simple connector, accelerated HD video, and no fan requirement.

UGM offers broad interface support and digital/analog video input capability. It simplifies design with a proven all-in-one AMP/Tyco connector, delivering all in and out signals. Its 12-V power supply matches that of the COM Express itself, and it can provide a single voltage supply of up to 130 W. UGM is designed for the embedded market, advancing COMs graphics with one connector, no cables, increased shock resistance, and low power consumption, supported by long-term availability as an embedded component.

UGM leverages the knowledge and design expertise behind COMs and was created to fit COM Express design concepts. Its associated design risk is low based on its independence, interchangeability, and upgradability. UGM is expected to drive new applications, such as powerful video walls. It is suitable for enabling higher resolution and increased data-capture speeds in portable and ultraportable medical devices. Medical electronics engineers can learn more about UGM by reading a detailed technical overview at www.ugm-standard.org.

Portable Devices Drive Portable Data

Although the portability of medical devices is certainly important to patient health, it is the portability of the data that is key to saving lives. Paper medical charts with handwritten notes are not readily accessible, sharable, or, in many cases, even readable. In fact, today’s paper-based records will soon be a thing of the past. The migration to electronic medical records is one initiative propelling new applications that collect, interpret, and transfer data to reduce human error and improve diagnoses.

Other advances include automation. Instead of a nurse taking a patient’s blood pressure and entering the data manually, the blood pressure armband will be connected directly to the tablet PC. From there, the data are automatically extracted and populated into the system, minimizing human error and increasing accuracy of information. A small, portable ultrasound unit will take digital images that will reside directly in the patient’s electronic chart for easy viewing and sharing by medical staff.

Portability of equipment combined with portability of data are driving medical device designers to push the limits of what they currently design—devices that provide greater efficiency, reduction of human error, quick-turn diagnostic capabilities, and seamless information gathering. Whether it be preventive care or treatment of serious illness, these are the tools that will improve healthcare from the quality of the doctor-patient relationship to the accurate diagnosis and treatment of patients.

Being successful in medical design means focusing on core competencies and building a product that stands out among the competition. Getting there first is pretty important too, as designers work to stake out their turf in various areas of medical specialty. Outsourcing selected components means that medical electronics engineers can focus on these core competencies. Choice of architecture is often dependent on function, and for small, portable designs, COMs have solidified their place in medical electronics.