Medical Device Design: Challenges of Miniaturization and Harsh Rural-Clinic Environments

By Contributed Article | March 16, 2013

Medical Device Design – Challenges of Miniaturization and Harsh Rural-Clinic Environments

Smaller, lighter, more portable, and more affordable are the primary objectives for just about every medical device manufacturer. The demand to succeed in achieving these attributes is particularly strong from remote medical clinics in rural settings, where funds are often scarce.

In light of Congress’s recent decision to not repeal the medical device excise tax, manufacturers are currently looking for any competitive edge they can gain. Succeeding in the tele-health initiative to enable healthcare devices to reach more people in remote places will go a long way in helping manufacturers differentiate themselves. They can enable doctors to provide medical care using the most advanced technologies.

Design Considerations for Medical Devices in Harsh Conditions

Design engineers producing medical electronic diagnostic and monitoring devices for rural clinics face the challenge of developing products that work in harsh environments, such as extreme temperatures and non-traditional shock vibration. These conditions typically do not exist in hospital settings.

The choice of system interconnects is a key consideration when designing devices that stand-up to harsh conditions. One approach taken by leading interconnect manufacturers

is to stack PCB board-to-board connectors with very low profiles (heights of 0.7mm) that feature a narrow footprint (2.5mm wide). Such interconnects also typically come with high retention-force, dual-contact systems to provide strong locking for electrical signal integrity.

The leading providers offer stacking connector material that is high-temperature LCP plastic rated up to 260ºC and plated in gold flash (4µ” minimum), which is the best signal contact plating material for harsh environments. Another key interconnect attribute is a small pitch, in the range of 0.2mm.

Connectors with these attributes are critical because medical device designers need to pack more and more features into thinner and smaller spaces. Connector density and thermal management are thus ongoing challenges.

Micro-Electro-Mechanical Systems (MEMS) technology is helping by enabling a 60% reduction in space requirements compared to the traditional stamped and formed connectors. The MEMS technology in micro flex-to-board and board-to-board applications has also been tested to withstand up to 60G shock/vibration. In addition, the technology can provide up to 5A of continuous current for low power. These attributes enable medical devices to perform well when subjected to harsh applications.

Heat Dissipation Critical for Portable Devices

As for heat sinks, medical devices such as tablets, portable ultrasounds, and diagnostic monitors are now designed with the fastest and newest IC chips to run complex algorithms. As they become smaller and more user-friendly for patients and doctors, these devices generate more heat, making it difficult for traditional heat sinks to work effectively.

To resolve this thermal management challenge, new FGHP (Fine Grid Heat Pipe) technology spreads the heat more quickly away from the heat source while reducing the size and weight of the required copper material. FGHP technology also saves space with a low profile (2mm height) and allows medical devices to work more efficiently.

For both connectors and heat sinks, medical device designers must ensure they use materials in their device designs that require as little space as possible and hold up to the harsh conditions that many rural clinics present. This approach improves the performance and endurance of devices to help increase market share over the long run, a critical objective for an industry that is ever-ready to evolve for the needs of the future.

As the micro products division-Lisle satellite team manager at Molex, Joe Falcone has 15 years of experience in the interconnect industry in various sales, marketing, global business development, and product management roles. He holds a BSEE in electrical engineering and an MBA in finance/marketing. Falcone’s experience in product management and product development has focused on the consumer, mobile, computer/telecom, and medical industries.

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