The vast array of medical devices in hospitals fills the environment with noise. This affects equipment performance and is a cause for concern among manufacturers. For this reason, the medical industry has turned its attention towards developing smaller, more compact equipment.  Most of these ultra-modern medical devices are made with Injection molded plastics which help them to meet strict performance requirements. Non-conductive in nature, these plastic components are excellent at preventing EMI emission and penetration, thereby facilitating smooth gadget functionalities.  Even then, conductive coatings, which consume almost no volume at all within electronic devices, are applied. The right amount of coating can help design engineers meet cost budgets.  For this reason, manufacturers of modern medical equipment that utilize injection molded plastic shielded enclosures use conductive coatings to impart cost-efficient, reliable performance.

A Point to Remember While Using Plastic Enclosures for Medical Devices

To be used in the medical industry, any equipment must have three basic characteristics, namely,  chemical resistance, thermal resistance, and EMI shielding. Hence, just about any plastic materials will not do. Manufacturers must procure the items from a reputable supplier with suitable experience and a reliable supply chain.

shielded enclosures

When choosing the right materials for a new medical electronic device, manufacturers will benefit from having a qualified design partner who can guide them towards success. After all, the price is not always indicative of quality, and designers should focus more on materials that best fit their enclosure criteria. So, having a good design and manufacturing service saves both time and money by preventing mistakes that might end up costing more in the long run. A design partner may even suggest new solutions that address upcoming device design trends, such as EMI shielding, and offer a unique, cost appropriate look representing the best the brand has to offer.

EMI Prevention in Medical Devices

Devices, especially the ones with smaller dimensions, require a design approach that is streamlined using basic EMI shielding design practices. But the more complex the equipment, the harder it is to shield the entire system against the debilitating effects of electromagnetic interference. For example, equipment such as interventional lasers, injection systems, and diagnostic devices often rely on lasers, electric motors, power hardware, and high-power lamps for efficient performance – all of which emit EMI radiation.

Manufacturers will encounter difficulties while achieving electromagnetic compatibility (EMC) with complicated medical systems. But the use of modest EMI control methods at the front end of the design cycle removes various issues and minimizes their impact down the line.

Designing the Proper Enclosure for Medical Devices

The first step towards developing a fully-functional shielded enclosure for medical equipment involves designing the ground. While designers are free to use as much metal as required, injection molded plastics will always be the better choice. But irrespective of the material used, care must be taken to ensure that the mating surfaces are nearly continuous or continuous. Depending on the material choice, the joints will either be welded or secured using screw fasteners.

Modules must be positioned carefully, so the ones interfacing with the outside world remain near the enclosure boundary. Every module must be bolted directly to the ground, leaving the contents isolated. The conductive mating surfaces must have low impedance. Otherwise, hinges, latches, screw threads, and shudder bearings are unsuitable for low contact resistance. But if the design demands these components, a ground strap must be present that goes around.

Unfortunately, this type of setup poses certain problems when electronics are mounted on the door panel. For starters, a good ground connection is necessary between the access door and the housing.  Thankfully, the problem can be resolved easily by routing a ground strap between the door and the housing and running interconnections alongside the ground strap. Moreover, manufacturers must exercise caution when running cables through a cable shield and grounding them at both ends.

EMI shielding in medical equipment requires careful planning. To make their devices foolproof, manufacturers need to choose the right shielded enclosures. Besides, they must also focus on other aspects of design so that the equipment receives total protection from harmful EMI radiation.