Staying Connected - July 2013

Custom or Off-The Shelf Medical Connector Design Path

A custom connector allows each
design element to be incorporated

When designing a new device, one of the decisions that medical device makers are faced with is choosing a connector and mating receptacle.  For some applications, a standard, or off-the-shelf connector, is a viable option.  For other applications, a custom or hybrid connector may be more appropriate..

Reasons why a device manufacturer may consider a custom medical connector instead of an off-the-shelf connector are:

  • A unique design is required to assure that only a specific cable or connector can be mated to the device
  • The shape of the connector needs to match the profile of the device
  • A variety of signal types must be carried within a single connector (high voltage, low voltage, high bandwidth, data, thermocouple)
  • An off-the-shelf connector is may not meet the cost target
  • Custom logo or markings on the connector are desired or required
  • Lead-time for an off-the-shelf connectors may be unacceptably long

Safety may be enhanced by designing a custom connector.  Unique pin-to-socket patterns or connector shape can prevent mating by incompatible connectors thereby enhancing safety.

Custom 11 contact connector

Custom connector fits contour
of device case

A custom connector will typically involve engineering and tooling fabrications costs.  These up-front charges can be a roadblock to selecting a custom connector solution.  However, once the costs to design the connector and fabricate tooling are realized, a custom connector can often cost much less than an off-the-shelf connector.

Physical Properties

With a custom connector solution, each desired physical property can be addressed.  A custom connector can be designed so that mate and un-mate force matches specific customer requirements.  This force is composed of the friction from each pin and socket as well as the mechanical interface of the connector and receptacle.

Moisture protection is often a consideration in medical interconnect systems.  Off-the-shelf connectors typically incorporate shells and pre-molded boots or collars.  When these components are assembled into a finished connector, they often do not offer the required degree of ingress protection.  Custom overmolded connectors can be designed with any required ingress protection (IP) rating.

Standard boots typically do not provide
high levels of ingress protection

Custom edge card connector designed
to mate directly with PCB

Availability of connectors from major manufacturers can also be an issue with lead times of 8-16 weeks being common.  Once tooling has been fabricated, the lead time for custom connectors can be much shorter than for off-the-shelf connectors.

Design Requirements

Establishing detailed design requirements is one of the first steps in determining whether a custom or standard connector is the best option.  Factors that may require consideration include:

  • Number and type of contacts (pins or sockets and specifications for each)
  • Cable configuration (ECG, defib, power, analog, digital, bandwidth, pneumatic, fiber optic, or combination of two or more.)
  • Cable diameter, materials and shape
  • Regulatory and environmental ratings (RoHS, REACH, ISO 10993, UL)
  • Strain relief requirements
  • Shielding requirements for both the connectors and the cable
  • Voltage and current requirements
  • Size constraints and/or desired physical size
  • Ingress protection (IP) requirements or rating
  • Number of mate and un-mate cycles required
  • Locking mechanism – if any
  • Keying requirements
  • Desired mate and un-mate force
  • Cleaning, disinfection and sterilization requirements
  • Logos, markings and serialization

Custom connector with
customer’s branding

Keyway prevents non-keyed
connector from being mated

Components of Custom Connectors

A custom connector typically involves an injection molded hard plastic insulator into which pins, sockets or both are inserted.  Termination of conductors to the pins or sockets by solder or crimp is most common.  This assembly is then overmolded with a rigid material such as polypropylene which holds the construction together and provides physical strength.  A second overmolding with a material such as a thermoplastic resin or silicone gives the connector the desired color, finish, look and feel.

Hybrid Connectors

For some applications, a hybrid connector may be the best option.  A hybrid connector is an off-the-shelf connector with custom features such as an overmolded grip or strain relief.  Design and tooling costs for a hybrid connector can be less than for a custom connector yet the finished product can have the look, feel, and some of the additional performance advantages of a custom connector.  Besides lower engineering costs, a hybrid connector can have a shorter design and development schedule than a fully custom connector design.

Off-the-shelf connector with custom overmolded bend relief becomes
hybrid connector

Hybrid 3M MDR connector with custom
angled overmolded strain relief

Freedom to Design

Example of custom ECG plug and
custom case-mounted receptacle

Affinity is in a unique position when compared to most connector manufacturers.  Because we are not a connector company, we routinely incorporate connectors from all major manufactures into our products if this option best matches our customers design requirements.  Since we are not constrained by legacy connector designs, we are free to create an entirely new connector when a unique interface is required.


A custom or hybrid connector can provide unique features and benefits for medical devices.  Each design element can be addressed with less need to compromise as compared to using an off-the-shelf connector.  Safety and reliability can be enhanced and a custom connector may be a more cost effective solution.  However custom and hybrid connectors typically require a greater investment in engineering and tooling than an off-the-shelf connector.

Whether you need a custom connector, an off-the-shelf connector or a hybrid connector, the Affinity engineering team can help.  Affinity Medical has decades of experience and expertise in designing and manufacturing custom medical connectors and cable assemblies.  For additional information, please contact Affinity at +1 949-477-9495 or email to

^ back to top


Meet Maggie Carranza – Project Engineer

Maggie Carranza
- Affinity Project Engineer

Maggie joined the Affinity engineering team in April 2013 transferring from Molex headquarters in Lisle, Illinois to Southern California.

Recruited from the Illinois Institute of Technology, Maggie began her career with Molex 16 years ago.  Her first position, before graduating, was assisting the marketing team create a technical cross reference of competitive connectors.

After graduating, she was able to put her technical education to use for the cable assembly production line at Molex’s Nogales plant.  As a product coordinator she traveled frequently and was also able to be involved in new product development.

One of Maggie’s early successes was creating a sales tool to make quoting custom cable assemblies faster and easier.  What had often taken two to three weeks was shortened to as little as one to three days by using the system she created.

Promoted to an Associate Engineer in Molex’s Commercial Products Division, Maggie stepped into new product development and was awarded her first of three U.S. Patents for a unique switch design for a SIM card reader connector.  Promoted to a Design Engineer Maggie began working on custom connector solutions for various markets, while earning her Master’s in Business Administration in Management of Innovation and Technology from Benedictine University.

Maggie was promoted to Project Engineer in 2004 after developing a product line of smallest blind-mate interconnect system and joined the Backplane Group where she worked for eight years in a team developing Molex own brand of high speed interconnect systems.  “The pace of product development was fast in the Backplane Group,” Maggie said.  “We went from design concept into prototype builds in 3 months and into fully automated mass production in six months.  This is because continuous development of new products and launching them faster than competition is an important part of Molex’s business.”

U.S. Patent 6,802,746, one of Maggie’s three patents

Maggie said she enjoys challenges of new product development and therefore was intrigued when she saw the internal posting for a Project Engineer position at Affinity.  “I was looking for an opportunity to work for a new venture for Molex, with greater challenges and smaller teams,” said Maggie.  “The position at Affinity seemed like it offered both.  I am very passionate about Affinity’    s products and customers.”

Affinity Engineering Manager, Matt Pathmajeyan commented, “Maggie is a bright and articulate engineer with many years of project engineering experience at Molex. We are excited that she is now part of the Affinity/Molex engineering team and I look forward to her growth within the organization.”  General Manager Bob Frank offered, “Maggie has a “can do” attitude and is willing to take on most any engineering challenge.  Maggie arrives at work each day with an infectious smile.”

“Relocating to Southern California’s warmer climate was good for our daughter’s health and also put us closer to family in Colorado,” said Maggie.  From the time Maggie accepted the engineering position in the Costa Mesa plant to her actual move was only six weeks.  “I think it was meant to be,” said Maggie.  “We found a house in two weeks and everything worked out for us to make the move very quickly.”

Born in Warsaw, Poland, Maggie and her family emigrated to the U.S. in 1989 and settled in the Chicago area.  She was an independent teenager, working at 16, playing tennis and enjoying arts and crafts.  “Math was not one of my strengths; I was a more creative person, designing and fabricating my own toys as early as I can remember.  No project was ever too big or too complicated; I always accomplished what I was set out to do.  Design and development was always a big part of my life and that’s why I am an engineer.”

Maggie was naturalized as an American citizen only two months after 9/11 and said, “It was very emotional to become a U.S. citizen right after the country was attacked.  I was raised in Poland while it was a communist country and really appreciate the freedom we enjoy in the United States.  I consider myself patriotic and appreciate the opportunity to vote.”

Inspiring kids to become interested in engineering was always important to Maggie, so over the years she volunteered in multiple events sponsored by Molex to introduce kids to engineering careers.  Most recently, Maggie volunteered as a Board Vice President at her daughter’s school and wrote two major award-winning grants sponsoring STEM education (Science, Technology, Engineering and Math).  Maggie hopes that her daughter will follow her parent’s career path.  “She builds these amazing structures with such creativity, patience and civil engineering skill, and then runs off to put on her tiara and her princess dress.”  Maggie laughs and adds, “I think girl engineers are awesome!”

Maggie and her husband Carlos met while both worked for Molex.  They now live with their daughter Natalie Grace in nearby Lake Forest.

^ back to top


Announcements, Information and Trivia

George Eastman – U.S.
photographic inventor
and pioneer – image U.S.
Library of Congress

Twelve very expensive
Hasselblad cameras have
been left on the moon!

Nikon cameras are
recognized for quality
around the world

Photography Trivia

Kodak – U.S. photographic pioneer George Eastman had a fondness for the letter ‘K’. He reportedly said, “It seems a strong, incisive sort of letter.” He came up with the name ‘Kodak’ for his company with help from his mother and registered the name in 1888.  A year later The Eastman Company was founded and in 1892 it was renamed The Eastman Kodak Company.

Moon Cameras – The U.S. has left 12 very valuable Hasselblad cameras on the surface of the moon in order to accommodate the extra weight of lunar rock samples to be returned to earth.

Most Expensive Camera – The most expensive camera ever sold was a 1923 Leica which was sold at auction in Austria for $2.8 million U.S. dollars.

Polaroid Land Camera – Edwin Land invented the first commercial instant camera in 1948 which was sold and known by combining the name of the company he founded eleven years earlier, Polaroid, with his name.

Nippon Kogaku – a Japanese company founded in 1917 manufactured and sold the first Nikon branded camera in 1948 and is, today, one of the most respected photographic brands in the world.