Staying Connected - June 2008

Applying ANSI/AAMI EC53 to Cable and Leadwire Design


ANSI/AAMI EC53 standard

When we work with customers to design new cable systems one of the typical requirements is that the design must “meet EC53.”  What is EC53 and how does it affect medical cable design?

The primary goal of EC53 was to promote patient safety by helping prevent inadvertent connection of patient leads to a power source, as well as allowing more rapid transfer of a patients requiring continuous monitoring in emergency care.

Because ANSI/AAMI EC53 specifically addresses ECG cables and leads, it may not be directly applicable to other medical cables systems.  However, lacking more specific standards, EC53 is often used as a base upon which to build specifications for other medical cable applications.

ANSI/AAMI EC53 is a voluntary standard that promotes safety and reliability by defining minimum mechanical and electrical requirements for compliant cables and leadwires.  Minimum requirements for labeling and packaging as well as cleaning and sterilization are also formalized within the standard.

Mechanical Requirements

To establish minimum mechanical performance of cables and leadwires the standard contains requirements for the number of mate and un-mate cycles, connector retention force, flex life of components and tensile strength.  Cleaning, disinfection, and sterilization minimums are also documented.

Minimum mechanical performance specified in EC53 is generally adequate for ECG cables.  Other diagnostic or therapeutic uses may place lesser or greater mechanical demands on the cable.  As an example a cable used to connect an implanted ventricular assist device may need to withstand hundreds of flex cycles a day for several years or more.  For VAD applications, EC53 mechanical requirements are likely inadequate.  On the other hand, a cable designed to be used for EEG studies may be able to have lower mechanical requirements because of the limited motion and type of use the cable will be normally subjected to.

Electrical Requirements

Minimum performance standards for critical electrical requirements are also defined in EC53.  One requirement is for defibrillation withstand.  Excessive current should be prevented from traveling through the cable to the connected device to assure the entire electrical pulse is delivered to the patient and also to protect the connected device.


Testing for triboelectric
noise in Affinity test lab

Noise in a medical signal may make accurate diagnosis difficult or treatment less effective.  Shielding can help reduce or eliminate EMI noise, but cable movement alone can produce unwanted triboelectric noise.  This issue is addressed in EC53 by establishing maximum peak-to-peak noise of 50µ volts and a standard test method to confirm the noise levels.

Other electrical requirements called out in ED53 are for dielectric withstand (Hipot), sink current, and contact resistance.  Each are generally considered a reasonable requirement for most medical cable assemblies.


EC53 provides a standard for
cleaning medical cables

Cleaning and Sterilization

Another area in which EC53 requirements can act as a basis to establish a specification on is cleaning and sterilization.  Sections 4.3.1 of EC53 address cleaning cables fifteen times using “green soap,” glutaraldehyde, and bleach.  Because in practice cables are typically cleaned more times and with stronger cleaning solutions, more stringent requirements are often called for.

Testing

Finally, EC53 provides test methods and procedures by which compliance to the standard can be verified.  Test equipment, circuits, and specific procedures are detailed and allow uniform and consistent testing.  Test methods defined in the standard can be applied to most medical cable assemblies often with modification of the performance results.


Affinity Engineering Associate
Bob Evans performing Hipot
testing on medical cable

Affinity Medical and EC53

While ANSI/AAMI EC53 specifically addresses ECG cables and leadwires, it is often used as the basis to establish performance requirements for other medical cables.  Part of the design and development process at Affinity is work with our customers to review and apply applicable electrical and mechanical requirements of EC53 to their medical cable design.

The engineering team at Affinity Medical can help you establish appropriate specifications and requirements for your cable system.  Using our experience in cable design and knowledge of EC53 requirements we can help you achieve your design goals and meet regulatory standards.

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Meet Mayuri Patel – Engineering Technician

Mayuri Patel has been with Affinity almost as long as the company has been in existence.  Mayuri joined Affinity Medical over nine years ago and has contributed to Affinity’s success by her skills and abilities in a number of different positions.

Mayuri moved to Irvine, California from London, England with her family ten years ago.  She took a year off to concentrate on helping her family to settle into their new home and to raise her son, Sushil.  Mayuri started her career at Affinity Medical as a production associate.  She soon moved to receiving/inspection and then to quality control and now is a member of the engineering group.


Ever smiling Mayuri Patel

With a Bachelor of Science degree in Physics and Chemistry, her technical knowledge and expertise in cable production was evident and extremely helpful in the manufacturing of new and difficult projects.  Mayuri is always willing to assist the Production and Quality Managers whenever called upon.  

Mayuri was recently promoted to Engineering Technician, responsible for designing new cables and connectors.  She also manages engineering projects and works closely with customers and suppliers throughout the design phase to assure a smooth transition into production.

Mayuri has had extensive training in AutoCAD, Access database and SolidWorks.  Always eager to learn, she continues on-going training with Bob Frank, Affinity’s Director of Engineering.  Recently, Mayuri successfully completed her largest project to date; a new cable system with custom connectors that is now in production for a happy customer.



Recent custom connectors
designed by Mayuri Patel

When asked what she likes most about her job at Affinity Medical, Mayuri replied; “I really enjoy learning new things and the daily challenges of my job.  I am very happy when I start a new project in Solidworks, create the design and complete a project that pleases the customer.”  Mayuri also commended Mary Phillip, our President and CEO on her belief in,”the importance of our families which allows employees the flexibility to attend to family needs whenever necessary.” 


Mayuri is filmed at Affinity
for feature on women who
work in technical jobs

When Mayuri is not at Affinity Medical, she spends time with her husband Bhupen and her son Sushil.  Her family attends Hindu temple together regularly and they are very active in the social events that celebrate their Indian culture and traditions.

Mayuri is at the top of her class at Irvine Valley College where she is studying electronics.  On June 9th, Mayuri was be featured on the Women Tech World website, (www.womentecworld.org.) which focuses on women who work in technical jobs that are usually held by men.   Way to go, Mayuri!

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Affinity Medical Technologies Celebrates 11 Years!

Affinity Medical Technologies is now in its 12th year of operation and recently celebrated with an 11 year anniversary party for employees and members of the Affinity “family.” We look forward to an exciting future as the company develops its resources and expands into new markets.   The entire Affinity team is constantly working to accomplish the same goal: to achieve excellence in everything we do.

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Announcements and Information

Upcoming Holidays

National Flag Day is June 14th
Display our flag proudly


Father’s Day is Sunday June 15th

FATHERS are:
    

Independence Day - Affinity will be closed Friday, July 4th in celebration of Independence Day.

 


Suzann Sitka and Candy Golding
the Affinity Customer Care team

Affinity Customer Care - Hours of Operation

Affinity Medical Technologies customer care specialists are available from 7:00 A.M. until 4:00 P.M. Pacific time.

You may reach us by phone at 949-477-9495 or email to customercare2@affinitymed.com.

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Affinity Medical Technologies

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