Medical Device Link.

DESIGN

Medical devices are becoming more complex and technologically advanced. Many now incorporate electronics with embedded software that is difficult and expensive to develop, validate and maintain. The standard development approach to medical devices with embedded software is to define the requirements well in advance, develop the appropriate software and then validate that it meets the requirements. However, because there could be millions of these devices deployed in the world, any change to the embedded software is expensive.

A critical issue is how medical device manufacturers create products that are complex and yet low cost to develop and manufacture whilst remaining responsive to future needs. The answer can lie in thin-client medical devices. They are cheaper to develop and provide the flexibility required to survive in a rapidly-changing environment. Thin-client medical devices have the additional benefit of opening up opportunities for more revenue generation or providing a better service.

Thin-client architectures

For large, complex software applications, there are usually two sides to the system. The “client” side is responsible for receiving input and displaying results to the user. The “server” side is responsible for processing the input and producing the results. For this client–server architecture, there is, therefore, a question concerning how much logic is placed into the client and how much into the server. Thin-client architectures place as much as possible of the processing burden on the server rather than on the client. The best example of this is accessing an Internet application. The “client” is an Internet browser such as Internet Explorer, which has no processing power of its own and merely displays formatted text. The “server” is the website providing the text to be displayed, which will normally be a more process-intensive system, for example, searching for stock, price and matching titles on Amazon.

The advantages of thin-client architectures are

• lower IT administration costs: these are managed almost entirely at the server end, thus there are fewer points of failure and the local environment is restricted
• easier to secure: no application data need reside on the client
• lower hardware costs: the client hardware is basic and therefore cheap
• worthless to thieves: the intellectual property remains on the server and there is nothing on the client worth stealing.

Lower-cost medical devices

A thin-client medical device is a medical device that adopts the principles of thin-client architectures, that is,

• it is designed to have as little functionality as possible on the device
• it communicates to a central server.

Figure 1. Authentication at the point-of-dispensing, used in an anticounterfeiting service for drug products.

A barcode and radiofrequency-identification scanner from Aegate¹ is an example of a thin-client medical device (Figure 1). The scanner was designed to do as little processing as possible, deferring responsibility to the central database. The scanner is employed in a global anticounterfeiting service for drug products and determines authentication status at point of dispensing.

Development

Experience in developing products and processes within a regulated environment shows that is it unwise to specify all requirements in advance. In particular, it is virtually impossible to understand the problem space well enough to comprehensively define all of the requirements whilst still maintaining cost and development timescales.

Flexibility in requirements and the thin-client approach is better for many product life cycles because it permits the majority of development to take place on the central server. The overall development cost of the software will be lower because more development takes place on the central server as opposed to the embedded device. Embedded software development can cost up to three times as much as conventional software development.

Manufacture

Figure 2. System for noninvasive monitoring of vital physiological parameters.

A thin-client medical device will also benefit from reduced on-board functionality because this requires fewer or less-able components such as less memory or a lower specification processor, which will reduce the cost of the device. In addition, size and battery capacity are often important considerations for medical devices. Thin-client devices, with fewer components, will require less space and less battery power. For example, a noninvasive monitoring system from Critikon² took advantage of simplifications to save a significant amount of its unit cost (Figure 2).

Future-proofing

Thin-client medical devices can be highly responsive to changes in business processes. Because any changes to the business processes will happen on the server, these can be controlled more easily and can be seamlessly rolled out to all deployed medical devices. In contrast, a change to business processes for a conventional medical device, for example, a different algorithm for a heart defibrillator, would require a recall of all existing devices, followed by a complex and expensive upgrade procedure.

Easier to validate

Because the medical device itself is as simple as possible, it will be significantly easier to validate than if it is developed conventionally. There will be some increase in cost on the server side as a result of the increased burden on the server. However, validation of the business layer on the server will be significantly easier than on the device, because the server-side software will not be embedded and will therefore be more available.

Open channel to the consumer

As well as reducing the cost and complexity of the medical device, thin-client medical devices provide additional value and revenue opportunities for the manufacturer by opening a channel to the consumer. These additional opportunities include

• direct communications between manufacturer and consumer such as for recalls, advertising and sales
• gathering of data on how the individual consumer is using the product n remote diagnosis using the data provided by the device.

Adoption

Thin-client medical devices require a diverse range of skills for

• design and development of the medical device
• development of the embedded software
• communications to the server
• understanding of the underlying IT hardware and infrastructure
• development of the server/enterprise software
• understanding of the manufacturing process and selection of manufacturing partners.

Thin-client architectures provide an effective way for medical device manufacturers to reduce the bottom-line cost of their business. In addition, for manufacturers seeking to increase their revenue streams, thin-client architectures will help to open up new areas in a competitive market place.