Staying Connected - September 2013

Designing a Custom Medical Cable – Anatomy of a Project

Affinity has developed systems and procedures that allow new product development projects to be completed in a timely manner and ensure that the finished product meets customer specifications and expectations.  Affinity is a U.S. FDA Registered Medical Device manufacturer with Design Control and Product Realization procedures in compliance with FDA Quality System Regulations and also applicable elements of ISO 13485.



Example of a complex cable assembly
that required a cross-functional team
for successful development

The Team Approach

Designing and manufacturing medical cable assemblies as medical devices is best accomplished using a disciplined team approach.  The size and make-up of the team is generally dictated by the complexity of the project, but should include members from both the OEM device maker and the cable design team.

Project Scope
           
Understanding the project scope is the first step in both the design process and establishment of an effective team.  Projects vary in scope and several types of projects are listed in order of ascending complexity:

  • Build to print cable assemblies using existing off-the-shelf components and connectors
  • Transfer of existing custom cable assemblies, which include custom components and connectors, from a legacy supplier to a new manufacturer
  • Improvement to an existing cable assembly which will require re-design of custom components and/or custom connectors
  • New interconnect system which requires custom components and/or custom connectors and which includes multiple cable assemblies

Generally speaking, the more complex the project, the greater the resource requirements will be.  Understanding the resource requirements is an important step towards successful completion of a new product development project.

Project Review and Acceptance

A manufacturer may have more opportunities to participate in new product development projects than can be successfully managed.  At Affinity, potential projects are reviewed before making a commitment to quote or accept the project.  Some factors that are considered include:

  • Commercial viability – it is likely that both the customer and the product will be successful?
  • Resource and revenue balance – will the cost of the resources required to design the product and transfer it to manufacturing be recovered by revenue from manufacturing the product?
  • Capabilities match – are the requirements of the project, including engineering and manufacturing within the capabilities of the company. 

If the project passes the initial review – deemed to be a viable new product development project for Affinity - it will move to the quotation or proposal stage.

Quotations and Proposals

Quoting a new cable or cable system requires communication with the OEM customer.  While some projects will be presented with drawings, specifications and even a bill-of-materials, communication is still needed to understand the “soft” requirements including how the product will be used and who will use it.  Often there are expectations for the product that are not stated in the supplied documentation which will influence the design of the product.

Another important consideration is the target cost of the product.  Knowing the target cost will allow the product to be designed and engineered with materials and components that are likely to meet the target.  A target cost will also help determine whether the product will be manufactured domestically by Affinity or by one of Molex’s off-shore locations.


Costs of raw materials and components
such as contacts are obtained as part of
the quotation process


When a target cost is not available it is often desirable to offer a budgetary quotation.  A budgetary quote can help the customer understand what development costs, including tooling may be as well as an estimate of production pricing.  A budgetary quote that is in-line with the customer’s expectations generally leads to a formal quotation or proposal.

Sourcing raw materials and components and obtain pricing for such can take several weeks.  While the materials group is obtaining this information, engineering will be establishing labor to build the part and estimating non-reoccurring charges such as tooling, assembly fixtures and unique test equipment.  Once the cost of materials and amount of labor is known, a quotation can be prepared and presented to the OEM customer.

The Project Team and Kick-Off Meeting

Once a purchase order or other suitable commitment has been received from the customer, the Affinity project team is formed and a project kick-off meeting with the customer is scheduled.  Successful new product development projects are the result of teamwork – teamwork between the medical OEM and the design and development team at Affinity.

Depending upon the scope of the project one or more engineers will be assigned to the project.  In addition to assigning design engineers the Affinity project team will also include one or more representatives from:

  • Customer Care
  • Manufacturing
  • Manufacturing engineering
  • Quality
  • Materials sourcing
  • Product management
  • Sales engineering

At a minimum, the customer team should include representatives from engineering, quality and materials/NPI purchasing.

During the kick-off meeting a point-of-contact for both the Affinity team and customer team will be established.  It is common as a new product development project progresses that the point-of contact will change.  When this happens the change is communicated to all team members.



Designs are reviewed carefully
by a cross-functional team at Affinity

Team Meetings

One of the keys to a successful new product development project is regular communication.  To facilitate communication, Affinity establishes regular team meetings, generally conducted either by phone or on-line.  For complex projects, weekly meetings are held and for less complex projects, bi-weekly meetings are common.

“We don’t want there to be any surprises for our OEM partners,” said Affinity Engineering Manager, Matt Pathmajeyan.  “By holding regular team meetings, publishing action items, and reviewing them at the next meeting, our engineering team is able keep projects on track.  One of the results of regular reviews is that our OEM partner always knows the status of their project and is not surprised if there are any changes to the timeline.”

Direct Communication

While regularly scheduled team meetings greatly facilitate communication, the team should be open to direct communication between any team members.  It is both common and desirable for engineers from both the customer and Affinity to have direct, one-on-one communication.  Similarly, team members from the customer’s quality or NPI procurement groups can communicate directly with their counterparts at Affinity.  If a question needs to be answered or an issue needs to be addressed, immediate and direct communication is beneficial.

Design Input

One of the most important aspects of a new medical cable design project is design input.  Design inputs are the electrical, mechanical, physical and performance requirements of the device that will be used as a basis for device design.  In addition to electrical, mechanical and physical requirements, an understanding of how the product is intended to be used is necessary and should include:

  • What need is the new cable assembly fulfilling
  • Where and by whom will the device be used
  • With what other devices will the new cable assembly interface with
  • How long is the assembly expected to last and under what conditions
  • What safety, regulatory and industry standards is the new device required to comply with
  • What labeling and packaging are required

The more the design team knows about the proposed assembly and how it will be used, the more likely it is that the finished product will meet all of the customer and user requirements.

The Product Specification

Once sufficient design input is received and understood, a draft of the product specification can be written.  The product specification should be as detailed as possible and should include all electrical, mechanical and physical characteristics and requirements.
 
Design Reviews

Throughout the design process design reviews are held.  Required design reviews are conducted at several stages of a new product development project based on Affinity’s Design Control Process.  Additional design reviews are held as the complexity of the project dictates.


Solid models are carefully studied
as part of design review

Fabrication of mold tooling is not begun
until all stakeholders in the project
have reviewed and approved the design

If new mold tooling is required for the project, solid models or prototypes will be shared with the customer for approval before tool fabrication is begun.  “Because we conduct multiple design reviews and include all stakeholders, we have confidence that when we start cutting steel the finished tooling will produce the desired parts,” commented Matt.

Product Qualification


Tensile strength testing is
a common element of DVT testing


All new cable development projects require some level of qualification.  Some require only design verification while others also may require process qualification.

Design verification confirms that the product produced meets the product requirements.  A reasonable amount of design verification testing (DVT) is included as part of non-reoccurring engineering charges (NRE) when projects are quoted.  The Affinity engineering team drafts the DVT protocol based on the product specification and once approved internally, shares it with the OEM customer for their approval.  Once the protocol is approved and initial parts are manufactured, the test protocol is executed and the results are reported to the team.

Production part approval process (PPAP), adopted from the automobile industry, confirms that the product can be consistently manufactured, meeting all critical requirements.  Because PPAP requirements vary, they are quoted as a separate non-reoccurring engineering charge.

Design controls required by the U.S. FDA for medical device manufactures and the requirements of ISO 13485 include some PPAP elements.  Other elements may include

  • DFMEA
  • Process Flow Diagram
  • PFMEA
  • Control Plan
  • Part Submission Warrant

Qualification activities, including PPAP and DVT testing can have a significant impact on the project timeline and should be addressed in the early stages of project planning.

Project Timeline

One key to a successful project is an accurate project timeline.  Affinity uses Microsoft Project® to record and track project milestones and responsibilities.  The project timeline is established by the project engineer and reviewed to ensure that it meets the customer’s requirements.

Once established, the timeline is reviewed during team meetings and if changes are made which will affect the schedule the timeline is re-published to team members.

Summary

To successfully design and manufacture medical devices known as cable assemblies requires a team approach - a team made up of both the OEM device manufacturer and Affinity.  All of the OEM’s requirements will be incorporated and the result will be a medical device that can be produced repeatedly with consistent quality.

If you would like additional information on how Team Affinity can help with your cable or connector project, please contact:

  • Your local Molex Sales Engineer or Account Manager
  • Affinity Business Development Manager, Jim Itkin – Jim.Itkin@Molex.com
  • Affinity Customer Care - customercare2@affinitymedical.com or +1 949-477-9495

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Meet Emily Clark – Product Manager



Emily Clark, Product Manager

Emily joined Affinity in April 2013 stepping into a newly-created and much needed Product Manager position.

Born and raised in Buffalo New York, Emily began her career as a Marketing Intern with Moog Space and Defense while attending State University of New York at Geneseo.  After earning her Bachelor of Arts in Business Administration she joined Moog in 2007 as a Marketing Communication Specialist.  In 2009 she was promoted to Marketing Manager and the following year Emily earned her MBA from Canisius College.

In 2011 Moog offered Emily a position in Southern California as Product Manager for the Spacecraft Mechanisms Division which she accepted and relocated.  “I was interested in experiencing life outside of Buffalo,” said Emily.  “Initially I said that I was willing to go anywhere except California.  But, when I was offered a position by Moog in Southern California it was both the right opportunity and right time so I made the move.”

“We were less than thirty minutes into our first interview with Emily when I knew she was the right candidate for the job,” said Affinity Marketing Manager, Hank Mancini.  “Her background and experience matched our open position perfectly and I could tell that she would fit in well with the people and culture at Affinity.  Our decision to hire Emily has proven to be a good one!  She does a great job interfacing with our OEM customers, the Molex Sales Engineers and the entire Affinity team.”


Emily works closely
with Affinity Engineering Manager,
Matt Pathmajeyan



As Product Manager, Emily coordinates new cable development projects.  She receives and reviews requests to develop new cable assemblies from Molex Sales Engineers and also directly from OEMs.  “A big part of Emily’s job is handling requests to develop new products,” said Hank.  “To evaluate and subsequently quote a project requires a lot of documents.  Emily has a done a great job of organizing our current paper system and is in the process of implementing a paperless system.  Besides handling the paperwork, Emily does a great job of interfacing with our OEM customers.”

Asked, what was the most difficult aspect of her new job Emily replied, “It was difficult adjusting to the medical market from aerospace at first.  I had to learn new terms, procedures and certifications.  And, the engineering approach is different.  However, after four months I am pretty comfortable.  The medical devices which Affinity manufactures are more tangible than the aerospace products I used to work with.  I can relate to how our products are used with medical devices.”

Besides work, Emily goes to the gym to work out every day.  She is also active in the Junior League of Orange County, an organization that stresses volunteerism and mentoring of young adults, both women and men.  During hockey season Emily says she never misses a Buffalo Sabres game.

Emily’s parents live in Buffalo and she has a brother who lives in Texas.  While Emily says she is enjoying Orange County, living in nearby Newport Beach, she enjoys going home to Buffalo whenever possible.

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Increasing Tensile and Flex Life Performance of Cable Assemblies

Most medical cable assemblies use standard stranded copper as the conductor material.  When the appropriate gauge and stranding of the conductor, as well as jacket material, insulation and fillers are specified, a cable assembly that fully meets ANSI/AAMI EC53 requirements for tensile strength and flex life can be produced.  If additional performance is desired or required and the gauge of the wire cannot be increased, one option is to use a high performance copper alloy for the conductor material.

Bare 28 gauge stranded copper conductor, commonly used in medical cable and lead wire assemblies, has a tensile strength of approximately 5.2 pounds.  When a shield and jacket are added to the bare copper conductor and terminated properly, the tensile strength is typically increased.  Tensile strength at the termination is typically above 12 pounds, in excess of the ANSI/AAMI EC53 requirement of 7 pounds.


Tensile strength comparison copper vs. copper alloy conductor

In comparison, a common copper alloy conductor often used to improve performance has a tensile strength of approximately 8.2 pounds, about 60 percent higher than standard copper.  With similar construction of a shield and jacket, tensile strength at the termination is above 18 pounds, a significant improvement that results in a more robust assembly.

If the cost of using copper alloy conductors is prohibitive for the product, increasing the conductor size will increase the tensile strength.  As in the previously cited example, 28 gauge stranded copper conductor has break strength just over 5 pounds.  Increasing the conductor diameter from approximately .4mm to .6 mm - by using 24 gauge conductor - increases the tensile strength of the conductor alone to over 12 pounds.

In addition to an increase in tensile strength, the flex life performance of copper alloy conductors is greater than standard copper conductors.  For the same gauge of conductor, copper alloy conductors can exhibit two to fifteen times the flex life before failure.

If you would like more information on the option of using a copper alloy or a different wire gauge or configuration to increase the performance of a cable or lead assembly, contact the Affinity Engineering team.

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Announcements, Information and Trivia



The flags – top
to bottom – of
Guinea-Bissau,
Guinea and
Equatorial Guinea


Kilimanjaro – the
highest mountain on
the African continent

Geography Trivia

Three Guinea – the African continent is home to three countries with very similar names.  All are located on the west coast of Africa with Guinea-Bissau and Guinea located at about 9 degrees north latitude and Equatorial Guinea located virtually on the equator.

Did you Know? - The first foreign country you encounter heading south from Detroit Michigan is…Canada!  The city of Windsor, Canada is located just across the Detroit River and due south of Detroit.

Time Zones – China and the continental United States both have about the same land mass.  Both are approximately 5,000 kilometers (3,100 miles) across.  The continental United States is divided into four time zones: Eastern, Central, Mountain and Pacific.  China is composed of a single time zone!

Peninsulas - Europe is a collection of peninsulas and nearby islands. The two largest peninsulas are "mainland" Europe and Scandinavia, separated from each other by the Baltic Sea.  Iberia (Spain and Portugal), Italy and the Balkans are three smaller peninsulas.  These five peninsulas make up most of the landmass of Europe.

High Mountains – the highest mountain within the continental United States is Mount Whitney which is 4,421 meters (14,505 feet).  In contrast, Africa has six peaks higher than Mount Whitney