Staying Connected - November 2010

Encapsulating Electronics in a "Smart Cable"

As medical devices become more sophisticated, requirements for medical cables and interconnect systems are becoming more complex.  This often leads to the requirement that electronics to be incorporated into a connector or cable system.  A cable assembly in which active electronics have been incorporated is often referred to as a “smart cable.”

Often the need arises to add electronic circuitry to a medical device without redesigning the device itself.  One option is to add the necessary electronics in an external housing connected by a cable assembly. This is a common situation where legacy devices need to be made compatible with newer technologies.

Cooperation between device manufacturers has increased the need for dissimilar medical devices to be interconnected.  One way to facilitate communication between different devices is to use an external cable assembly with imbedded electronics to handle the signal translation.

Enclosure Options


Overmolded electronics
package provides shock
and vibration resistance


Clamshell enclosure –
injection molded halves
ultrasonically welded together

Hybrid enclosure – inner
ard plastic clamshell with
overmolded outer surface

The three most common methods used at Affinity to incorporate electronic assemblies into cables are:

  • Overmolded or encapsulated electronic circuits
  • Clamshell housings
  • Hybrid enclosures

The optimum enclosure method is dependent on a number of factors including size, durability, ingress protection requirements, cost, development time and the look and feel of the final assembly.

Direct Overmolding

Of the three options, overmolding active electronic components presents the greatest challenge for manufacturing.  Molding typically involves injecting hot thermoplastic material at high pressure into a cavity where the electronic assembly is suspended.  The temperature of the injected material does not typically cause solder to reflow, but the mechanical forces present in the injection process can damage the components and affect the electrical integrity of the PCB.


PCB with active components
before molding


Complete overmolded “smart cable”
converts RS232 signal to USB
compatible signal

An additional obstacle to overcome when directly overmolding electronics is the effect on components due to shrinkage of the thermoplastic material as it cools.  Experience has taught us that this failure mode must be considered when specifying materials, designing tooling and establishing molding parameters.

Overmolding directly over a PCB typically involves an inner and outer mold.  The inner mold adds mechanical strength and is commonly used to anchor any cables and connectors.  An outer overmold finishes the assembly, adding the desired look and tactile feel as well as providing areas for branding and labeling.

Direct overmolding of electronic components adds additional opportunities for failures due to the nature of the molding process.  Because of this, it is generally advantageous to confirm the electronics are functioning properly at various stages of the molding process and to conduct a final functional test prior to shipment.


Custom connector with PCBs
before overmolding. Finished
connector will withstand
sterilization by autoclave

Even considering the manufacturing challenges, encapsulating electronic components by overmolding offers a number of advantages:

  • Is durable and improves resistance to vibration and shock
  • Has an appealing look and tactile feel
  • Offers a high degree of ingress protection
  • Is more difficult to reverse engineer, adding a level of security

Clamshell Enclosures


Interior of custom enclosure with
flexible strain relief and PCB standoffs

One common alternative to directly overmolding electronic circuit boards is using two injection-molded clamshell pieces that fit together, holding the electronics package.  This enclosure may be a simple box with a top, or more sophisticated with interlocking groves and a gasket to achieve a waterproof seal.

Stock clamshell enclosures are available from a variety of sources, but they are rarely found in the exact configuration needed.  Openings for cables or connectors may not be present, may not be in the right location or of the right size.  Rarely do stock enclosures have appropriate features to mount PCB’s or provide anchor points for cables or wiring.


Clamshell bottom with PCB
wired to cable before top
is permanently attached

An alternative is to design a custom clamshell enclosure.  A custom clamshell enclosure can be designed to precisely match the size of the electronics package and can also be contoured to look like it is part of the cable assembly.

A custom clamshell can be designed to be permanently sealed or reopened, depending upon the application.  Ultrasonic welding or adhesive is commonly used when the enclosure is permanently sealed and screws are often used when the enclosure is designed to be reopened.  If an enclosure is designed to be screwed shut, screw placement can often be hidden by labeling.  When a label is used to cover screws, it can also act as a deterrent to tampering because the label will not remain intact if the screws are removed to open the case.

 

Hybrid Enclosures


Clear clamshell case holds and protects
circuitry from direct overmolding


Finished assembly after overmolding
inner clamshell with softer
thermoplastic material

Hybrid enclosures are a combination of hard plastic cases overmolded with a softer thermoplastic material.  Typically for this type of construction, the clamshell case is filled with a light weight potting material before being overmolded.  If this is not done, mold pressures could collapse the case.

There are several advantages to this type of enclosure including:

  • Protecting the electronic components from the temperature and pressure of direct overmolding
  • Achieving a lighter weight assembly by using a fill material that is lighter in weight than mold material
  • Producing larger overmolded electronic packages than could be achieved by direct overmolding.

With a hybrid design, the outer mold can be designed to follow the contours of the inner case allowing a uniform wall thickness.  A uniform wall thickness will typically produce a more consistent outer surface even when large assemblies are encapsulated by overmolding.

Summary

Incorporating electronic circuits into external enclosures can offer medical device manufacturers additional alternatives.  The Affinity engineering team has experience designing and manufacturing a wide variety of enclosures and incorporating circuits, connectors and cable assemblies.

For more information on how Affinity can help you with “smart cables,” external enclosures, custom cable assemblies and connectors, contact us at customercare2@affinitymed.com or call us at +1 949-477-9495.

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Meet Hank Mancini – Affinity Medical Business Development Manager


Hank Mancini – Affinity Medical
Technologies Business
Development Manager

Hank Mancini joined Affinity nearly four years ago as Business Development Manager.  He brought with him more than thirty years of experience in the medical industry.  While managing a Tyco Healthcare (now Covidien) plant in Huntington Beach, California he worked with many current Affinity team members.  “Joining Affinity was almost like coming home,” Hank said.

 Although Hank’s title is Business Development Manager he enjoys being involved in all aspects of the company.  In addition to selling, Hank oversees marketing - including trade shows, Affinity’s monthly card mailings, the company’s web site, and “Staying Connected,” this electronic newsletter.  “I like to keep busy and one way to do that is to always have multiple projects to work on.  If there is any down time, I always have something else productive that I can immediately jump to” said Hank.

When asked what he likes most about his Affinity, Hank replied, “I appreciate and am completely “in tune” with the customer focus that our President, Mary Phillipp insists on.  Mary understands and that without our customers there is no need for Affinity.  Mary has attracted a wonderful and talented group of people which makes Affinity a great place to work.  We all work hard to satisfy our OEM partners.”


Hank and Teresa on the
Lakers court at Staples Center

Much of Hank’s time is spent traveling to visit medical device manufacturers across the country.  “Mary Phillipp and I often travel together.  We feel that it is very important to meet with our OEM partners and prospective customers face to face,” said Hank.  “While travel is expensive in terms of both time and money, there’s no substitute for personal contact.”

When asked to tell something interesting about himself, Hank said, “My first car was a Goliath!  It was a 1956 model that I bought in 1963 for $200.00.  My Goliath had front wheel drive which was an oddity at the time.  It was manufactured in Bavaria, Germany by Borgward-Lloydwerks.  If I still had it today, it would probably be a very valuable car because I have never seen another one!”


Hank’s 1956 Goliath

Hank and his wife Teresa live in Huntington Beach, share six grown children and have four grandchildren.  They are huge Los Angeles Lakers fans attending most home games for the past ten years.  Besides the Lakers, Hank enjoys digital photography, reading, red wine and dark chocolate.  Hank is a big fan of the TV reality shows The Amazing Race and Survivor.

Hank and Teresa share their home with Kobe, their 8-year old pug, Magic a year old cat, and Gumby their 9-year old Eclectus parrot.

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MEDICA 2010 Wrap-Up


The Affinity team at Medica

Once again, Affinity Medical exhibited at Medica - World Forum for Medicine, the world’s largest medical exhibition and trade fair.  The exhibition was held Wednesday, November 17th through Saturday, November 20th at the Messe in Dusseldorf, Germany.  Affinity’s stand was located in Hall 9, one of the main halls for medical device manufactures.

Mary Phillipp said “The show was noticeably busier this year as compared to 2009.  We had more visitors to our stand and the mood of the other exhibitors we talked to was upbeat.  One of the things that always amaze me is how many U.S. customers we have the opportunity to visit with while we are at Medica in Germany.”

One of the highlights of the show for the Affinity team was when German Chancellor, Angela Merkel visited the Getemed stand.  Getemed was showing their new device which features a cable assembly manufactured by Affinity.

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Announcements, Information, and Trivia

Holiday Trivia - Christmas Tree Lights

The first Christmas tree lights were small candles attached to tree branches with wax or pins.  Because of the high danger of fire, people generally did not put up their trees with lights until Christmas Eve.  Even then, fires were common.

To reduce the risk of Christmas tree fires, Edward Johnson, an associate of Thomas Edison, invented electric Christmas tree lights in 1882.  In 1895, President Grover Cleveland set up a tree in the White House which had electric lights.  That started the tradition that is common around in many parts of the world today. 

Affinity will be closed Friday, December 24th and Monday December 27th to observe the Christmas Holiday and to give our team members a much-deserved four-day weekend.

The Affinity team is grateful for the continued support from each of our OEM partners.  Affinity exists because of you.  We wish you and your family a wonderful, healthy and happy Holiday Season.




Suzann Sitka, Cesar Jara and Candy Golding
- the Affinity Customer Care Team

Affinity Customer Care and
Hours of Operation

At Affinity Medical, we don’t have a customer service department.  In place of customer service, we have Customer Care Coordinators.  While our Customer Care Coordinators perform many of the same functions that customer service representative would, we strive to offer our OEM partners more than that.  The job of our Customer Care Coordinators is to take care of our OEM customer partners.

Affinity’s Customer Care team consists of Candy Golding, Suzann Sitka and Cesar Jara.  Candy is the team supervisor and has over twenty years experience working with medical cables.  Suzann Sitka joined Affinity over five years ago.  She has extensive experience, having worked for several medical device manufactures before joining Affinity.  Cesar is the newest member of the team, joining Affinity in mid 2009.

Affinity Medical Technologies Customer Care specialists are available to assist you from 7:00 A.M. until 4:00 P.M., Monday through Friday U.S. Pacific Time, except holidays

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Affinity Medical Technologies

1732 Reynolds Ave
Irvine, CA 92614  USA
Phone: +1 949 477 9495
Fax: +1 949 477 9499
Email: CustomerCare2@affinitymed.com
Website: www.affinitymed.com