By Sean Fenske, Editor-in-Chief
 
Medical technology is getting more advanced quite rapidly. Devices are being developed with more electronic components and being made “smart.” They are following trends seen in consumer products, such as 4k televisions or video game systems. This evolution presents an array of challenges for designers.
 
One such obstacle to success can be ensuring the right connection solutions are identified for a variety of medical equipment. Whether a patient monitor, surgical system, or diagnostic device, connecting the technology properly and sufficiently to fulfill all power, data, and other needs has to be correct.
 
To ensure device manufacturers are using the correct connector or considering the best cable for their product, Steven Lassen, senior customer applications engineer at LEMO USA, has addressed a number of questions about this subject to help clarify what factors designers should be considering. He discusses fiber optics, electronic connectors, and high density design.
 
Sean Fenske: When it comes to the design of electronic medical devices, what are the most common requests or considerations you are seeing?
 
Steven Lassen: Customers are requesting connectors with higher bandwidth to accommodate high resolution video displays such as 4K. For some longer cables, this can become a problem with copper-based signals. Changing to higher bandwidth fiber optics solves the length issue but brings up other challenges such as more frequent cleaning of the fiber optic endface. The medical industry has a learning curve when adopting standard fiber optic connectors in the aspect of maintaining clean endfaces.
 
Another common request is the need for higher voltages in patient treatment with multiple contacts within the same cable. This can be a challenge to respect the safety standards while also maintaining a small connector size.
 
Fenske: Why should designers of these devices consider high density design?
 
Lassen: Surgical instruments held by hand need to be lightweight to minimize fatigue during long operations. Connectors with higher density contact arrangements allow for smaller conductor AWG and closer pin spacing, as well as a lighter weight and smaller size. More electrical contacts for additional sensors allow for higher precision in diagnostic, imaging, and treatment applications.
 
Fenske: What are the challenges that need to be addressed with high voltage?
 
Lassen: Patient and user safety is of the highest importance. Using high voltage for patient treatment while combining multiple contacts within the same cable can be a challenge, as there is a balance between meeting the electrical safety standards with respect to creepage and clearance, while also maintaining a small connector size.
 
Fenske: What impact are fiber optics having on medical device design and what advantages does the technology provide?
 
Lassen: With the need for higher bandwidth and data transfer, fiber optics offer a solution. Single mode and APC fibers offer the highest performance; however, the use of these types of physical contact (PC and UPC) requires cleaning as the core is only 9 um. Multimode fiber is a bit better with a 50/62.5 core, but it can still be difficult for the medical personnel to remember to clean the endfaces of the fiber. As a solution, expanded beam fiber connectors allow for a much larger surface area for easy cleaning.
 
Fenske: What are the most common missteps device manufacturers make with regard to the design of electronic medical devices and how does LEMO help resolve those issues?
 
Lassen: For connectors and cables, sometimes the conductors in the cable are too large to fit into the connectors so we will need to verify the electrical requirements and change either the cable or connector to match. Also, when customers need to combine high speed data and low power in the same connector, sometimes the throughput performance can be impacted by adjacent power conductors that cause interference. In those cases, LEMO offers suggestions on alternate pinouts or a more shielded data solution.

Learn more about LEMO here >>>>>