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Originally Published MEM Fall 2002

Device Networking

Enabling Medical Devices for Network Connectivity

With many manufacturers deciding to network-enable their devices, here are five tips for medical equipment manufacturers selecting a networking-enabling technology partner.

Tom Armbrust

Network-enabled devices can provide seamless connectivity between medical service providers and patients.
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More and more medical equipment manufacturers are faced with the rising customer demand to network-enable their products. For even non-technically-savvy customers, the value of networking—i.e., instant access to information, the capability to remotely monitor and control equipment, operational cost savings in remotely detecting and fixing faulty equipment, and much more—is becoming more important in doing business. Many times, customers simply decide that networking is something they need to do, even if they do not truly understand its value.

In any case, the customer demand compels many medical equipment manufacturers to speed up their development process to go to market with network-ready versions of their products. This issue addresses a critical decision that may affect the long-term profitability of a medical equipment manufacturer's product lines. Primarily, manufacturers must decide whether to develop a solution in-house or whether to use a ready-made technology. In-house networking solutions often take as long as 9–12 months because they require developing both hardware and software solutions to network-enable products.

Considering that it takes several months to develop a basic real-time operating system (RTOS) and another six months to develop a basic transmission control protocol/Internet protocol (TCP/IP) stack with application-level services like e-mail, file transfer, and a Web server, most manufacturers are inclined to purchase networking technologies from outside vendors.

This article discusses five high-level guidelines that a medical equipment manufacturer should consider when buying a packaged solution from a third-party vendor. Following these guidelines will minimize the time needed for developing network-enabled products. These guidelines should also help a manufacturer better evaluate vendors to determine whether they can assist in the area of network connectivity, as opposed to advising on networking technology options that already exist.

When considering a network-enabling vendor, manufacturers should assess the following five items:

  1. Migration Path. Does the vendor offer a migration path that addresses currently non-network-ready products as well as future, in-development products? In other words, can the vendor help network-enable legacy products that are already deployed, in addition to products that are in the design stages?
  2. Regulatory Compliance. Do the vendor's products adhere to regulatory requirements for patient security?
  3. Proprietary versus Open Standards. Are the vendor's products based on proprietary technology or are they based on open standards?
  4. Demonstrable Technology. Is the vendor capable of easily demonstrating its technology in a live, real-world application?
  5. Domain Expertise. Does the vendor have domain expertise? Has the vendor worked in the medical equipment arena, and does it understand the market?

Migration Path

Figure 1. In-house networking development compared with off-the-shelf options.
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A medical equipment manufacturer should consider a network-enabling vendor that offers technology to address the complete "life cycle of network connectivity" for its products. The life cycle refers to the evolutionary path that the design of a product undergoes on its way toward being network-enabled.

When a device manufacturer decides to network-enable products, it has to consider which of them are already deployed in the market, which are currently being sold, and which will be sold in the near and long terms. Products that are already deployed or currently being sold must use an accessory or add-on approach to provide network connectivity. Manufacturers must employ an external stand-alone box (also called a device server) that uses an existing serial port (RS-232, RS-422/485) to add network connectivity. Device servers typically have a DB9 or DB25 connector on the serial side and 10/100Base-T (RJ45) or 10Base-FL (ST) connection on the Ethernet side.

This design approach generally involves the highest per-unit component expense to achieve networking capability, but provides the quickest and easiest way to get a product to market. Device servers offer a packaged hardware and software solution that alleviates the need for manufacturers to spend a minimum of 9–12 months of development time in creating the solution themselves (see Figure 1). Some manufacturers have found that device servers provide backward compatibility in network-enabling their legacy products, which typically generates a new incremental revenue stream for a product line.

A network-enabling vendor must also have board-level and chip solutions for products that will be sold in the near and long terms, keeping in mind that these horizons are arbitrary. For the purposes of this article, near term refers to products that are 6–12 months away from scheduled general availability, and long term refers to ones that are more than one year down the road.

Even a 6- to 12-month lead time can be too short an interval for manufacturers to make design adjustments to a product. But a manufacturer can usually design-in a board-level solution that includes all of the elements needed for device networking: a processor, an RTOS, a robust TCP/IP stack, a Web server, and a network connection to provide an Ethernet bridge to a product.
Figure 2. An example of a board layout and pinout for an embedded device server.
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Board-level solutions of various sizes can be embedded into a medical electronic product for a moderate unit cost, and with smaller demands for development time and resources from a manufacturer. The only requirements imposed by this approach are adequate physical space for the board; an available serial port; and power, typically 5 V dc. Some board-level solutions are as small as a matchbook (see Figure 2).

For longer development cycles, a manufacturer may consider an Ethernet controller integrated circuit (IC). These chips come with various levels of integration, from simple media-access controllers (MACs) to chips that have the MAC as well as the physical-layer interface (PHY) electronics. Higher levels of integration incorporate a processor, memory, and a number of other interfaces that enable serial, parallel, infrared, fiber, and wireless connectivity. These single-chip solutions should come bundled with the necessary software and tools, including an RTOS, TCP/IP stack, and related network applications, to significantly reduce product development time.

The overarching idea behind the three levels of solutions is that a manufacturer can add network connectivity to any of its products at any stage of development or release. As a result, a network-enabling vendor should have a suite of products that fit the external, board-level, and chip categories (see Figure 3).

Optimally, these three levels of products should be built on the same technology for ease of assimilation into a product line. For example, if a vendor's external device server uses the same chip set that ultimately will be designed into an in-development product, then the design engineers will be familiar with the integration subtleties of both form factors.

Regulatory Compliance

The Health Insurance Portability and Accountability Act (HIPAA) of 1996 has strict guidelines regarding patient security and accessibility of information by authorized parties. Because any piece of medical equipment that is put on a network is a potential point of security risk, a network-enabling vendor must ensure that its products possess the highest levels of confidentiality security. As a result, this criterion becomes a critically important part of the evaluation by a manufacturer.

Proprietary or Open Standard?

First and foremost, manufacturers should be wary of proprietary technologies that provide network connectivity. These technologies may have compatibility problems with current operating systems and software applications as well as those yet to be developed. Manufacturers should consider the widely adopted, ubiquitous method of serial communication, which has been a mainstay of data transfer and acquisition.

The one issue facing serial communication is its limitation of distance. Recently, other communications standards have vied for wider acceptance as a communications medium, including USB, Bluetooth, and Firewire, just to name a few. However, these media are not yet widely accepted or utilized. They also share the same basic limitation as serial communications—limited distance.
Figure 3. Manufacturers should be able to add network connectivity to a product at any stage of development.
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One method of communication that has overcome the distance limitation is Ethernet and IP, which enables global data transfer and communication. Use of Ethernet in its different forms and widespread use of application protocols such as simple mail transfer protocol (SMTP) and hyper text transfer protocol (HTTP) has made IP the de facto standard of next-generation device communication. Therefore, manufacturers should ensure that any network-enabling vendor's solutions support Ethernet and IP as a means of communication. With this type of support, a manufacturer's product can connect to virtually any network in the world and is accessible from anywhere in the world through a Web browser.

Demonstrable Technology

Just as a person wants to test-drive a car before buying it, many manufacturers prefer to see a proof-of-concept of a network-enabling vendor's technology before they commit to purchasing it. Some vendors have established programs whereby they will perform a live, on-site demonstration of their technology.

Manufacturers should consider having a prospective network-enabling vendor provide a trial run of its technology with their products as part of the sales evaluation process. Typically, a vendor will use one of its external device servers to demonstrate the ease and speed with which the product can be connected to a network. As previously mentioned, the ideal circumstance is that the external device server uses the same chip set that would be used as an embedded solution for a product in long-term development.

Domain Expertise

Manufacturers should seek out network-enabling vendors that possess domain expertise in two arenas: networking and the medical industry. With so many mergers and acquisitions, there are many circumstances in which a vendor may "fall" into the networking space solely based on an acquired product. Manufacturers should investigate a vendor's longevity in the networking space, evaluate the company's track record, and pursue references of prior work. The primary questions that a manufacturer wants answered from a reference include the following:

  • How well did the technology actually fit into a product design?
  • How long did the integration into the product design take?
  • What kind of vendor support did the reference receive from the vendor during the integration process?
  • Was that support included in the purchase price?

Of course, one of the top-line questions is how close is the reference's application to that of the manufacturer who is calling. This question leads to the second arena of domain expertise.

A vendor should have experience in the medical industry that is derived from a previous development process with a manufacturer of medical equipment. Network-enabling an automobile or air-conditioning system is not the same as providing network connectivity for a blood analyzer, an x-ray machine, or a patient-monitoring system.

This observation seems simple, but it is sometimes overlooked by manufacturers. Obviously, understanding the intricacies of the medical industry (e.g., compliance with HIPAA) goes a long way toward shortening the development process and avoiding potential industry-oriented pitfalls.

Manufacturers that overlook a vendor's lack of medical industry experience should require price breaks in any development contract to compensate for technology problems that may arise.

Conclusion

For medical device manufacturers, device networking offers a true competitive advantage that enables them to provide value-added services for their customers, increase sales of new products, and enhance the use of existing products.

By adopting device-networking approaches sooner rather than later, a medical device manufacturer can help to ensure that it will remain competitive in terms of technological advances.

Tom Armbrust is the medical marketing segment manager at Lantronix (Irvine, CA), where he is responsible for the company's focus on medical device networking. He can be reached at 949-453-3990.

Copyright © 2002 Medical Electronics Manufacturing