Medical equipment design engineers are constantly challenged to develop leading-edge electronic devices that help improve patient care. Anthony J. Kalaijakis, Molex Incorporated, takes a look at the technologies paving the way for medical device innovations, including microminiature connectors
Over the last decade or so, there have been remarkable advances in the world of medical equipment, ranging from easy-to-use home monitoring devices for blood pressure and blood sugar levels, to complex diagnostic imaging machines, sophisticated robotics and laser surgery equipment.
However, today’s healthcare industry is undergoing significant changes due to recent reforms, and government and industry regulations and oversight are becoming ever more stringent. This means equipment and device designers need to ensure the quality, durability and reliability of the products they develop.
One significant trend is the medical industry’s growing adoption of the same electronic design strategies and components that have propelled the rapid growth of the consumer electronics and telecommunications industries in recent years. New design strategies have been built around increased demand for miniaturisation, mobility and portability – as evidenced by the proliferation of next-generation smartphones and other handheld devices, as well as notebook and tablet computers.
These market forces are similarly driving convergence of electronics and medical devices, impacting on medical device design engineers responsible for creating today’s next-generation of intelligent medical devices.
Networking is beginning to play a key role in medicine because, in many situations, collaboration of medical teams across geographic distances can reduce costs while improving the quality of medical care.
Telemedicine allows diagnostic images and test results to be transmitted between medical professionals in seconds – even in remote areas – via broadband networks to hasten potentially life-saving diagnostics and decision making. Another form of telemedicine involves establishing direct connections between physicians and patients at home. The higher bandwidths and data integrity demanded by these kinds of medical advances – whether used for digital imaging, voluminous data sharing or physician-patient interaction – have set the stage for all-digital fibre optic connections.
Fibre optics and laser
In digital imaging and diagnostic applications, optical fibre cables are increasingly replacing copper-based cables as they provide higher speeds for faster downloads and ensure more reliable, distortion-free electrical signal transmission – improving the image quality. Optical cables can eliminate ground loops and EMI/RFI, which provides better clarity on video displays of MRI and X-ray imaging.
Optical fibre is also being used in sophisticated laser surgical devices, which are becoming more common as a preferred tool for performing a multitude of minimally invasive therapeutic procedures and can typically result in shorter recovery times and lower risk of infection. Here, the laser’s light is transmitted using flexible optical fibre smaller than half a millimetre in diameter.
The demand for smaller and more portable form factors for medical devices is driving the miniaturisation of embedded electronic components and interconnects to unprecedented micro sizes. Microminiature connectors, for example, designed for use in mobile phones and handheld devices, have now evolved into viable medical device solutions.
When selecting these, product designers need to carefully assess and compare products to ensure that all performance and reliability requirements will be met. One popular connector, for example, has a 0.40mm pitch, a low-profile height of 0.70mm, and comes in several configurations to accommodate a variety of device designs.
It is important to note that, as portability increases and the size of devices decreases, power management becomes a major factor that must also be evaluated carefully. In the medical device arena, the scale of power requirements ranges from high power equipment such as MRIs, to small, battery-operated devices for home health monitoring. In both cases, the application requirements must be clearly understood and applied with a focus on patient safety, equipment performance and reliability, and energy conservation.
Ease of use and aesthetics are key factors in designing user interface pads and touch-point switches for home monitoring medical devices; and membrane switches not only provide an excellent value-to-performance ratio, but they are rugged, easy to clean and intuitive to use. Design elements may include such additions as embedded LEDs, dome arrays, silicone rubber keypad assemblies and multi-language capabilities.
Medical device design
The first axiom in the healthcare environment is ‘do no harm’ – which assigns a heady responsibility to those involved in developing products for the medical space. This becomes especially important in overlapping areas such as telehealth, where COTS (commercial off-the-shelf) components used in the telecom industry may conveniently appear to solve a technical challenge. But, these products must be vetted thoroughly to assess their suitability for the medical environment.
Some factors medical device designers must consider to ensure each product’s safety, performance and reliability include: the product’s operating environment, interconnect sealing requirements, bio-compatibility, intuitive operation, resistance to sterilisation and cycle life durability. Once these factors have been considered, you may find it necessary to tweak or modify COTS components to meet specific application requirements. In many cases, taking a MOTS (modified off-the-shelf) approach can be a practical alternative that allows for some level of customisation without the cost burdens of custom tooling.
Before selecting components, it can therefore be helpful to work with an industry leader in electronic design that is familiar with the application specifications across multiple industries.