Med-Tech Innovation Products and Services


PRODUCTS AND SERVICES


Successful Electronic Component Selection for New Devices


Designers need to make careful decisions when choosing the best components for their new designs.


The medical electronics market is estimated to be worth more than US$120 billion annually. Financing opportunities and new product design activity are in abundance, but medical technology companies must balance their desire to deliver leading-edge innovations against the need to ensure that each new product can be supported properly, that is, fully serviced and maintained throughout its lifetime. Although there are strict requirements governing medical technology


products such as the Medical Device Directive and US Food and Drug Administration (FDA) regulations, these apply at the finished product level only and are concerned with aspects such as design processes and quality systems. As far as individual electronic components are concerned, there are no independent qualification criteria such as the MIL standards used in sectors such as defence and aerospace. Medical product designers would be wrong to assume that component manufacturers will support any component in any or all medical applications.


In practice, individual component manufacturers offer different levels of support to customers who use their products in medical designs. This can also depend on the type of component and the nature of the application. It is important for product designers to be aware of these differences. A little research and knowledge can avoid potentially costly mistakes as well as provide a source of competitive advantage.


The right type of service To avoid unknowingly selecting the wrong components particular care is recommended when designing patient-connected or safety-critical equipment, because component manufacturers often state categorically that certain parts are not to be used in high-risk applications such as these. Mistakes have actually happened. In some cases, it has fallen to a distribution field applications engineer (FAE) to inform the product designer that certain parts really should not be included in the design, and to recommend a suitable replacement. Of course some manufacturers offer products that are aimed specifically at medical applications. Maxim (www.maxim-ic.com), for example, highlights specific products from its portfolio such as ADCs, amplifiers, protection devices and microcontrollers, and matches these to opportunities in home medical devices, imaging equipment, diagnostic/monitoring/therapy products and medical instruments. These products usually offer part-life longevity and they have been more stringently tested to ensure reliability in critical applications and potentially 100% batch testing. Some semiconductor suppliers have invested in ISO 13485 compliant manufacturing facilities, which allow them to address many applications, but more suppliers are focusing on the mass volume, non-life-critical consumer applications, where an adherence to FDA protocols, for example, is all that is required. In addition to providing technical support including detailed


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illustrations and product comparisons, special back-up from suppliers includes services such as Maxim’s minimal obsolescence policy. Minimal obsolescence extends design life, which is particularly important for equipment that must pass regulatory review or high-value products that are required to operate for several years before being replaced or upgraded. Analogue semiconductor specialist Intersil (www.intersil.com/ cda/home) provides similar application-focused services for medical device designers. Alternatively, some manufacturers recommend specific variants of


standard devices for medical designs and track these by batch, which enables them to respond to any product liability claims. Particular market variations could include special termination finishes to meet specific requirements for all surface mount or leaded components. These finishes can improve the solder fillet and ensure an exceptionally reliable solder joint. In additional, gold terminations can be replaced with tin-lead finishes for exempt applications. It is worth noting that components offered for medical applications should only be used as recommended. Standard terms and conditions tend to restrict use to non-critical sensing and monitoring applications. Written legal authorisation is normally required if components are to be used in products such as implantable devices or safety-critical equipment where failure may pose a significant risk to users.


COTS with caution The strong growth rates and rapid adoption of technological solutions to healthcare challenges present powerful incentives for medical designers to use cutting-edge technologies such as consumer multimedia or wireless devices. Similar to the use of commercial off-the-shelf (COTS) components in military projects, this approach can offer opportunities to differentiate a product, for example, by delivering a better user experience than competing devices. A COTS-type approach can be valid for equipment used in personal medical devices such as digital in-ear thermometers, blood glucose meters, CPAP machines and digital fertility/ovulation testers, which have relatively low value and are often marketed essentially as consumer products. However, the typically short market lifetimes of consumer


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