Staying Connected - September 2011

ANSI/AAMI EC53 – the ECG Cable and Leadwire Standard



ANSI/AAMI EC53 – the Standard for
medical cable and leadwire assemblies

The primary purpose 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 patients requiring continuous monitoring in emergency care.

Prior to the adoption of the standard, rare, but serious, incidents occurred when patient leads with exposed male pins were inadvertently plugged into power outlets.  The primary way that EC53 addresses safety is by defining cable and leadwire connections with no exposed electrical contacts.

Equally as important as safety issues are the mechanical and electrical performance requirements detailed within EC53.  Medical cable assemblies meeting the performance requirement of the Standard offer a degree of reliability that would likely not be present otherwise.

More often than not, our OEM partners establish higher performance and safety requirements than established in EC53.  Understanding the various components of the Standard facilitates establishing appropriate specifications for other types of medical cable assemblies.


EC53 defines the plug that
attaches the cable to the device
as the Instrument Connector


Definitions

Section three of EC53 contains definitions.  While the included definitions were meant to apply specifically to the Standard, they have become the most common terms that are used by medical device manufacturers when describing cable assemblies and connectors.

Physical Requirements

To achieve the safety and interchangeability goals for leadwire connection to a cable, EC53 specifies that DIN 42-802 be followed.  The DIN reference specifies pin and socket (plug and jack) dimensions as well as electrical contact setback to achieve a “touch proof” connector.

Mechanical Performance Requirements

To establish minimum physical performance of cables and leadwires, the standard contains requirements for:

  • Number of mate and un-mate cycles
  • Retention force of connector
  • Flex life of various components
  • Tensile strength of the connections and materials

Cleaning, disinfection and sterilization requirements are also specified within EC53.



Testing the tensile strength of custom lead
assembly using a motorized pull tester

Electrical Performance Requirements

Minimum performance standards for critical electrical requirements are defined in EC53, including:

  • Dielectric withstand, also referred to as Hipot
  • Sink current
  • Defibrillation withstand
  • Cable and leadwire noise
  • Contact resistance
  • Leadwire resistance for metallic, tinsel, and carbon materials

One significant requirement is for defibrillation withstand.  The cable assembly should help maintain the effectiveness of the defibrillation pulse by not allowing current to travel from the patient into the device.  It should also protect the device so that ECG monitoring can continue after defibrillation.

Noise in an ECG signal may make accurate diagnosis difficult, if not impossible.   Triboelectric noise can occur when a cable or shielded leadwire is flexed causing the internal conductors and other components to rub together.  Emergency care and stress testing are particularly susceptible to the generation of triboelectric noise because of movement of the cable.  The issue is addressed in EC53 by establishing a 50µV maximum for triboelectric noise and also a standard test method to measure cable noise.


Cable being tested in Affinity’s lab
for defibrillation withstand


Dropping weighted length of cable
to measure triboelectric noise

Testing Compliance


Affinity lab manager, Bob Evans and
lab tech David Moreno wiping cables
as part of EC53 compliance testing


Finally, EC53 provides test methods and procedures by which compliance to the Standard can be verified.  Test equipment, test circuits, and specific procedures are provided to allow uniform and consistent testing.  Affinity Medical’s in-house engineering lab is staffed and equipped to perform all tests associated with the Standard.

Similarly, procedures for complying with cleaning, disinfection and chemical resistance are specified by EC53.  At Affinity, cable assemblies are typically preconditioned prior to testing to help ensure test results mirror conditions found during clinical use.  Except for sterilization, preconditioning is done in Affinity’s lab.

EC53 Rationale

An annex to the specification provides the rationale for the development of the Standard and the various provisions.  Why each requirement is included in the Standard and the benefit of compliance is detailed.



Testing the durability of a cable
assembly by flex testing

Beyond EC53 Requirements

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

Depending upon the intended use, elements of EC53 may be either more or less stringent than the clinical application requires.  As an example, EC53 calls for a minimum of 300 mate and un-mate cycles for instrument connectors.  We recently completed a project where the cable was intended to be connected to the device and possibly never be removed.  Testing to 300 mate and un-mate cycles was neither reasonable nor required.  On the opposite end of the spectrum, another project involved a cable that would be implanted and was expected to function for five years or longer.  The 1,000 flex cycles required by EC53 were well short of the customer’s requirement of 250,000 flex cycles!


Affinity Director of Engineering,
Bob Frank was a member of
the AAMI Working Group that
developed the EC53 Standard


Knowledge of ANSI/AAMI EC53

Bob Frank, Affinity Medical’s Director of Engineering, was a member of the AAMI Working Group that developed the EC53 Standard.  Affinity Medical’s knowledge and experience can help shorten the design and development process by understanding which elements of the Standard are relevant to your application.

Summary

Involving the Affinity engineering team early in the design process can help achieve the desired results with an efficient design that meets applicable standards and regulatory requirements.

The Affinity engineering team has extensive knowledge and experience with ANSI/AAMI EC53.  We can help you apply the Standard appropriately to your medical cable or connector design.  For more information contact Affinity Customer Care at +1 949-477-9495 or email to customercare2@affinitymed.com.

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Affinity Partners With MPS-Terminal to Better Serve German-speaking Customers


Affinity Medical has formed a partnership with MPS-Terminal of Feldkirchen-Westerham, Germany to better serve our OEM customers in Germany, Austria and the German-speaking area of Switzerland.

“We have been trying to serve our customers in Germany by making two or three trips a year to Europe, but we realized that is just not enough,” said Affinity President and CEO Mary Phillipp.  “Germany is home to a number of the world’s leading medical device manufactures and we want to be more responsive to their needs.  Our motto is Staying Connected and we think we can better do that in conjunction with our partner MPS-Terminal.”

Affinity’s long-time European Business Consultant, Didier Chabault, identified MPS two years ago.  He was impressed with the capabilities of MPS, but more importantly he was impressed with the Company’s management and excellent reputation.  “I thought MPS would be a good fit with Affinity,” said Didier.  “We started working with MPS about a year ago, but only formalized our partnership earlier this year.  Being based near Paris, I cannot support our German OEM customers as they desire.  Partnering with MPS will allow Affinity to give better service.”

The MPS Group was founded in 1997 and currently has a team of 52.  MPS is ISO 9001-2000 certified and is in the process of being certified to ISO 14001.  MPS operates out of a 2,100 m2 facility that they moved into in 2007.  Affinity’s new partner MPS-Terminal is one of the operating companies within MPS Group.

MPS-Terminal represents a number of well respected manufactures besides Affinity including: Amphenol, Brady, Hypertac, Souriau, Switchcraft and TE Connectivity.


Lorenz Huber,
MPS- Terminal General Manager


Roberto Henker,
MPS-Terminal Business
Development Manager

Lorenz Huber is the General Manager of MPS-Terminal.  In August, MPS-Terminal hired Roberto Peter Henker as Business Development Manager specializing in the medical device market.  Roberto is very familiar with medical device manufacturers having worked for Hypertac Group for many years.  He is also very familiar with Affinity and Affinity’s design and manufacturing capabilities.

“We have known and respected Roberto for many years and are very happy to have him working for MPS-Terminal representing Affinity,” said Mary.  “He understands the unique demands of medical device manufactures and has an excellent technical background.  We’re proud to have Roberto, Lorenz and MPS-Terminal associated with Affinity.”

MPS-Terminal can be contacted at:

Lorenz Huber
Pfarrer-Huber-Ring 8
D-83620 Feldkirchen-Westerham
Germany
T: +49 (0) 8063-8101-300
www.mps-terminal.de
l.huber@mps-terminal.de
Roberto Henker
Breitenweg 1
88457 Kirchdorf                  
Germany
T : + 49 (0) 7354 9335 88
C:  + 49 (0) 151 46123594
r.henker@mps-terminal.de

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Meet Candy Golding – Affinity Customer Care Supervisor



Candy Golding – Affinity Medical
Customer Care Supervisor

When Candy joined Affinity in March 1999, the company was less than two years old, had 18 employees and 20 customers.  It has change a lot, but Candy’s dedication to providing excellent customer service has not!

As Customer Care Supervisor, Candy supervises two Customer Care Coordinators: Suzann Sitka and Cesar Jara, as well as Administrative Assistant Edith Cuatlayotl.  Candy reports to Affinity Business Development Manager, Hank Mancini.  Candy is responsible for several of Affinity’s largest OEM customers.

With over 12 year’s service, Candy has seniority over the vast majority of Affinity team members.  As such, she knows things about the company, our OEM partners and the products that we manufacture that few others do.  “Candy is the person we all go to when we need to know something that happened in the past.  She not only knows just about every product we have manufactured, she often remembers the part numbers,” said Hank.

Candy started her career fresh out of college working for Graphic Controls, a company that manufactured ECG chart paper and other cardiology-related supplies.  A few years after Graphic Controls expanded and acquired cable manufacturer Tronomed, she was transferred to that division.   She consulted with the sales team at Tronomed until it was acquired by Tyco and left voluntarily to join Affinity.

“Candy is always the first to volunteer whenever and wherever needed,” said Hank.  “If she sees something that needs to be done, she does it.  She not only does it, but she takes ownership and does it well.  Candy is one of the first to arrive and one of the last to leave.  She works hard and is very accurate.”


Candy reading names of those
celebrating birthdays during the month


In addition to providing excellent customer service Candy often works on special projects.  She is a trained Internal Auditor, has worked on Affinity’s Lean Manufacturing teams and has participated in projects that have streamlined the company’s MRP system.  Candy also helps out at the monthly birthday celebrations, being the “designated cake cutter” for years.

Candy’s customers truly appreciate her dedication and hard work on their behalf.  “I always ask about our service when I visit customers,” said Hank.  “Without exception, Candy’s customers say she is the best customer service person they have ever worked with.”

When asked what she enjoys most about her job, Candy said: “I consider myself part of our customer’s team and do whatever it takes to help them achieve success. When our OEM customers are successful, we are successful.” 

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