Staying Connected - June 2013

The Value of the Product Specification

One of the first steps in designing or developing a new medical cable assembly, connector, or other interconnect device is preparing a specification for the product.  The complexity of the proposed product dictates the level of detail required to be included in the product specification.  However, in almost every instance, the greater the detail, the greater the likelihood the product will be designed and manufactured as expected.

Product Description

The product description should
include what the intended use is
and who the intended user
of the product will be

It is helpful for a design team to understand what need the proposed product is intended to fulfill, who the product will be used by and how the product is expected to work.  As an example, the design of a cable may be different if the intended user is a patient verses the intended user being a medical professional who has experience with similar devices.

It is helpful if the description describes the environment in which the product is expected to be used.  A product designed to be used in a hospital setting may be designed differently than one intended to be used in an ambulance, even though both would likely be used by trained personnel.

A product description should help the team tasked with designing the product to understand the nature of the product and how and where it is intended to be used.

Physical and Dimensional Characteristics

Once the general concept of the new device is established, the physical and dimensional characteristics can be addressed.  Physical and dimensional characteristics may include:

  • Desired size or size constraints
  • Length of cable and/or leads
  • Cable and/or leadwire diameter
  • Specific materials – if any
  • Cleaning, disinfecting and sterilization requirements
  • Branding
  • Desired or maximum weight
  • Locking mechanism – if any
  • Ergonomic features
  • Keying


Because medical cables, connectors and interconnect systems typically carry a signal, power, data or any combination, electrical requirements are a significant part of the device specification.  Parameters that require definition and documentation include:

  • Number of conductors
  • Cable and wire shielding
  • Voltage and current ratings
  • Resistance
  • Capacitance
  • Bandwidth
  • Defibrillation protection
  • Polarization

ANSI/AAMI EC53 provides minimum
electrical and mechanical performance
standards for ECG cables and leadwires


Along with electrical requirements, defining mechanical requirements for a cable assembly or connector is necessary before design work can begin.  Requirements that require specifications to be established may include:

  • Flex life for each cable or wire termination point
  • Tensile strength for each cable or wire termination
  • Tensile strength of cable and wire material
  • Number of mate and un-mate cycles
  • Connector mate and retention force
  • Wheel rollover
  • Ingress protection rating (IP rating)

Minimum mechanical requirements for ECG cables and leadwires are established in ANSI/AAMI EC53.  While the requirements contained in this standard may be suitable for the intended use, other applications may call for higher requirements.  EC53 is often used as a basis upon which to build a product specification.


Regulatory requirements should be evaluated and documented in the product specification.  Regulatory requirements may include compliance to:

  • FDA
  • Medical Device Directive
  • IEC
  • RoHS
  • UL/CSA

Example of custom nameplate, details
of which should be included as part of
product specification

Labeling and Packaging

Medical cables and wires require labeling and marking for identification and to comply with regulatory standards.  While some may not give these specification the same importance as mechanical or electrical requirements, products cannot be sold without proper labeling and packaging.

Defining and documenting labeling, marking and packaging requirements as part of the original product specification will help ensure an on-time product release.  Typical labeling and marking requirements to be considered as part of the product specification include:

  • Brand labeling
  • Regulatory requirements labeling
  • Part number and lot or date code
  • Serialization – if required
  • IFU/DFU – instructions or directions for use
  • Required languages
  • Harmonized medical symbols
  • Bar coding
  • Packaging
  • Packaging for shipping

Characterization or programming requirements

For interconnect devices with active electronics, writing characterization or programming data to embedded electronics is becoming more common.  Defining what information must be recorded and equally importantly, how it will be verified should be part of the product specification.

If ESD protection is required
it should be part of the product

ESD Protection

With more active and passive electronics being incorporated into medical cables and interconnects, defining what level of Electro Static Discharge (ESD) protection is required for manufacturing and packaging should be incorporated into the product specification.

Cleaning and Sterilization Requirements

Unless designed for single use, medical cables and leads will need to be cleaned.  Even cables or leads designed for single use may require sterilization prior to being used.

If the product will be sterilized, the
acceptable methods must be included
in the product specification

Depending upon the use, cleaning may range from a wipe down with soap to the elimination of all micro-organisms by sterilization.  Cleaning and disinfection requirements

must be considered in the early product design so that appropriate materials and production processes will be specified.

Common cleaning, disinfection and sterilization methods include:

  • Green soap or alcohol-free hand soap
  • 2% glutaraldehyde
  • Sodium hypochlorite (bleach) solution
  • Isopropyl Alcohol 70 or 100%
  • Autoclave
  • Ethylene oxide
  • Gama radiation
  • Sterrad® (low temperature hydrogen peroxide gas plasma)

In order for the finished device to successfully survive cleaning, disinfection and sterilization, these requirements must be included in the product specification in order for the design team to address them when materials and components are selected.

Product Appearance and Aesthetics

It is helpful for the design team to understand what the finished device is expected to look like.  The appearance and aesthetics of a product will often be one of the key factors in determining how the user will perceive the product.  Some examples of descriptive statements that can help facilitate the design are:

  • A specific color (possibly to match corporate branding) or the desired effect of a color: e.g. “to reduce visible marks from normal handling”
  • Reduce features that can trap dirt and make cleaning difficult
  • Rigidity or pliability, hardness or softness of user interface surfaces: e.g. “soft rubbery feel”
  • Smooth edges and no sharp corners
  • Surface finish: e.g. “dull to eliminate glare or reflections”

If marks on an assembly will detract from
use or perception, calling out a dark color
in the product specification may be desirable

Often the originator of a new product has a clear idea of what the finished device should look like.  If those ideas are not documented and made available to the design team, the product may not turn out as the originator expected.

Component Specification

For a device to function as intended it may be necessary to require approved components to be used.  When this is the case, any required components, including manufactures name and part number should be listed and included in the product specification.


The value of a well prepared product specification is that it will generally shorten the overall project timeline and may also reduce costs by reducing or eliminating mid-project design changes.

The Affinity engineering team can assist you in developing your product specification.  To take advantage of our experience and expertise contact Affinity Medical at +1 949-477-9495 or email


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Meet Leslie Parra – Affinity Manufacturing Associate

Leslie Parra,
Affinity Manufacturing Associate

Leslie was raised and lives in nearby Santa Ana, California only about five minutes from the Affinity plant in Costa Mesa.  She did not know exactly what Affinity did when she applied for a job that she found on-line, but was interested because it was in the medical field.

Leslie joined the Affinity manufacturing team in August 2011 and worked until February when she took a break in her career to have her second baby.  She rejoined Affinity a few months later, in June 2012.

Leslie is now assigned to one of the work cells that manufacture cables for electrophysiology.  Before that she said “I worked in many different work cells and have had the opportunity to learn new things, which I like.  Learning to solder correctly to the IPC standards was the most challenging thing for me to learn”

After graduating from high school, Leslie completed two years of college earning certification for medical billing and front office.  Before joining Affinity she worked in an insurance office and as a receptionist in a doctor’s office.  “I am proud to say that I work in a company that produces medical devices,” commented Leslie.

Leslie working with Production Supervisor
Eric Schnitzler

Since joining Affinity, Leslie is proud that she has not missed a single day’s work.  “I take pride coming to work every day and being dependable,” said Leslie.  Asked about plans for her future Leslie replied, “I take each day as it comes.  I enjoy what I am doing and enjoy my family.”

Commenting about Leslie, Production Supervisor Eric Schnitzler said, “Leslie is a really a pleasure to work with.  She is positive, hardworking, liked by everyone, and generally a delight.”

Leslie is the mother children, a one-year-old girl and six-year-old boy.  Leslie works on first shift which means she begins work before it is light at 5:00 AM.  Asked about the early hours she commented, “I have gotten used to the hours.  The best thing is that I am home early in the afternoon for my children.”

When asked what she enjoys doing when not working Leslie replied, “I enjoy playing soccer and tennis.  I really enjoy outdoor activities.  For vacations, I like camping, hiking and fishing – anything outdoors.  I also enjoy reading and spending time with my family.”

“Affinity is a really good and comfortable work environment,” said Leslie.  “Everyone is very friendly and I like coming to work.”

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Bonded Leadwire

Connector end of 5-lead bonded leadwire set

One of the components that Affinity Medical has a great deal of experience in is bonded leadwires.  Affinity offers medical device manufacturers a wide variety leadwires including many configurations of bonded leadwires.

Bonded leadwires help eliminate wire tangle that is common when individual leadwires are used.  The longer the length and the greater the number of leads, the greater the opportunity there is for leadwires to become tangled.  Tangled leadwires can lead to incomplete monitoring, patient discomfort and frustrated clinicians.

Affinity offers bonded leadwires and in various configurations:

  • Tinsel, copper alloy or copper conductors
  • Shielded or unshielded
  • Two to ten leads
  • Various colors
  • Wire diameter from .040” to .120”
  • Polyurethane and Santoprene® wire jacket

Almost any length lead is possible and it is common that the bonded wires typically separate into individual conductors 12 to 15” from the patient end.  To keep the bonded section from separating further than desired a rip-stop is commonly added.

Bonded leadwires with wire diameter of
1mm, 1.5mm, and 2mm

Molded rip-stop prevents
bonded leadwires from splitting

The engineering team at Affinity has experience in designing bonded leadwire systems for medical monitoring.  If you would like to see samples of cables incorporating bonded leadwires, contact Affinity Medical Customer Care at 949-477-9495 or email to

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Announcements, Information and Trivia

Glaciers contain nearly 70%
of the earth’s fresh water

Our atmosphere, including
clouds, contains much of
the earth’s fresh water

Water vaporizes at 100º C
and is visible as steam

Water Trivia

Salt Water – 97% of the water found on earth is salt water, leaving only 3% as fresh water.

Glaciers – nearly 70% of the fresh water on earth is trapped in glaciers

Lakes and Rivers – less than 1% of the earth’s fresh water is contained in lakes, rivers and streams

Unrecognized Water – there is more fresh water contained in earth’s atmosphere than in all of the lakes and rivers on earth.

Physics – a gallon of water weighs 8.34 pounds and water vaporizes – aka boils – at 100º C (212º F)

Bread and Water - Due to the amount of water needed to grow wheat, it takes about 200 gallons of water to make a loaf of bread

You and I – water makes up between 55 and 78 percent of the weight of a typical human body