Staying Connected - January 2010

Ingress Protection and Medical Cables

It is often desirable and sometimes necessary to require protection against the intrusion of foreign objects, dust, or water into medical devices, including cables and connectors.  A method to clarify various degrees of protection is provided by the International Electrotechnical Commission (IEC) standard 60529.  Titled “Degrees of protection provided by enclosures,” it is commonly referred to as the Ingress Protection or “IP” Code.

Ingress protection is most often thought to mean protection against ingress of harmful water or moisture.  While moisture protection is one of the levels of ingress protection, keeping solid objects, such as a finger or tool, out of a device or connector is also a significant part of the standard.


IEC 60529 Establishes and
defines standards for Ingress
Protection of electrical devices

IEC 60529

IEC 60529, second edition is but one of many standards adopted by the International Electrotechnical Commission.  This standard defines degrees of ingress protection for enclosures including:

  • Protection of persons against access to hazardous components within the enclosure
  • Protection of components within the enclosure against harmful ingress of solid foreign objects
  • Protection of components within the enclosure from harmful effects of ingress of water or moisture

It is important to understand that IEC 60529 specifically address and strives to protect against harmful ingress.

The Ingress Protection Rating


Example of printed IP rating
on medical device

The Ingress Protection Rating is more commonly referred to as the IP code.  The IP code as defined in IEC 60529 pertains to the broad category of electrical enclosures.  An electrical enclosure may be an electric or electronic device, an electrical component, or as related to Affinity, a medical connector or cable assembly.  The IP code should not be confused with the term IP address, used in data communications.

IP ratings are generally presented as two digits; the first digit refers to protection against ingress by solid objects and the second digit refers to protection against ingress by moisture or water. 

For protection against solid objects level 2 is designed to prevent fingers or similar sized objects from touching hazardous components, such as electrical contacts.  Level 4 protection prevents contact by objects 1mm or greater and is often referred to as “tool-proof.”  Levels 5 and 6 offer dust protection, and level 6 provides complete protection against solid objects such as fine dust.

The second digit of the IP rating refers to protection of the device against harmful ingress of water or moisture.    Level 4 protection will prevent water splashed onto the enclosure from any direction from causing harm.  A device with level 4 water protection should withstand cleaning with liquids except for submersion.  It is important to understand that an IP rating does not indicate materials are able to withstand various cleaning solutions; only that moisture from those solutions will not enter the device in an amount to be harmful.

The IP Code Table

Level

Protected against

Details

Level

Protected against

Details

0

None

No protection

0

None

No protection

1

> 50mm

Protection against accidental contact by hand

1

Dripping water

Water dripping vertically will not cause harm

2

> 12.5mm

Protection against accidental contact by finger

2

Dripping water when tilted up to 15°

Water dripping vertically will not cause harm when the devices is tilted up to 15°

3

> 2.5mm

Protection against accidental contact by most tools

3

Spraying water

Water sprayed at an angle up to 60° from vertical shall not cause harm

4

> 1mm

Protection against accidental contact by small tools and wires

4

Splashing water

Water splashed from any direction shall not cause harm

5

Dust protected

Complete protection against moving parts and protection against harmful deposits of dust

5

Water jets

Protection against low pressure water jets from all directions snall not cause harm

6

Dust tight

Protection against penetration of dust

6

Powerful water jets

Protection against direct spray from all directions shall not cause harm

 

7

Submersion to 1 meter

No harmful ingress of water when submersed up to 30 minutes

8

Submersion beyond 1 meter

No harmful ingress of water with conditions specified by the manufacturer

Ingress Protection vs. Touch Proof


Recessed pins meet DIN 42-802
touch-proof standard

For medical cable assemblies and connectors, ingress protection for solid objects and a touch proof design are similar, but have slightly different design goals.  DIN 42-802 details the design of touch proof plugs and receptacles while IEC 60529 establishes degrees of protection, leaving the design undefined.

DIN 42-802 achieves a touch-proof design by establishing overall dimensions and a 1.5mm set-back for plugs and a 1mm set-back for receptacles.  The DIN standard goes beyond safety in attempting to establish interchangeability between manufacturers.


Inner mold provides
protection against ingress
of liquids or moisture

Achieving Ingress Protection for Liquids

Protection against harmful ingress by liquids or moisture is not difficult to achieve when addressed early in the design stage.  Protection is commonly achieved by molding thermoplastic material over other components.  When done properly, a high level of ingress protection is achieved without adding cost to the product.

Many medical connectors consist of insulators with pins or sockets inserted into hard plastic.  When overmolded with common thermoplastic materials, the assembly achieves a high degree of protection against harmful ingress by liquids.  Providing the same degree of ingress protection when mated to another connector requires additional engineering and design considerations.

The most common method to achieve a high degree of ingress protection between two connectors is for one side to be made of a hard material and the opposite side to be made of a softer material.  The size and geometry of the softer material is designed so that it must be stretched over the mating component.


IP67 connector system showing
groves in plastic receptacle
and soft outer TPR plug

To achieve a tight, waterproof fit, tooling is designed so that when first fabricated the fit of one component over the other is too loose, offering little ingress protection.  This tool-safe method requires subsequent machining to remove material from the mold for the outer component.  Each time material is removed from the tool, the fit of the molded part becomes tighter until the desired feel and level of ingress protection is achieved.

To achieve an IP X6 or IP X7 rating and maintain reasonable mate and un-mate force, ribs designed to fit into groves in the receptacle may be employed.

Summary

The need for ingress protection and the level of protection desired or required are elements that should be addressed early in the design phase of medical connectors or cable assemblies.  Affinity has experience and expertise in designing and manufacturing devices which meet our OEM partner’s ingress protection requirements.  If you would like to discuss ingress protection and how it relates to your cable or connector project, contact the Affinity engineering team.

^ back to top

 

Meet Nannette Filbeck – Affinity Information Technology Administrator


Nannette manages Affinity’s
network, email, and IT systems

“Help, Nannette.  My computer doesn’t work!”  This type request is very familiar to Nannette Filbeck, IT Systems Administrator, also known as Affinity’s “Computer Goddess.”

When Nannette re-entered the work force after raising three children, she resumed her career by accepting a position with Castrol Oil taking on such diverse positions as Customer Service, Sales Analysis, Purchasing and Information Technology.

Many at Affinity knew Nannette before she joined the team five years ago.  Like other Affinity team members, Nannette worked at Tronomed with Mary Phillipp and Bob Frank.  It was an easy decision to add Nannette to the Affinity team when the company switched from using an outside contractor to bringing IT services in-house.

Nannette is responsible for Affinity’s computer system and network as well as application programs and programming.  She is also responsible for the company’s communications needs including data communications, the phone system and company mobile phones – a lot of responsibility for one person!


A view of Pismo Beach –
oil painting by Nannette Filbeck

When asked what she likes most about working at Affinity, Nannette answered, “I like helping people and dealing with diverse situations.  Every day at Affinity is different and offers a new and exciting challenge to me.”  Nannette’s expertise and resourcefulness is greatly appreciated by everyone at Affinity Medical today.  “Nannette has done an excellent job of keeping all of Affinity’s systems up-to-date and virtually trouble free,” said Hank Mancini.  “She does a great job”

Nannette and her husband Leon live in Lake Forest (about fifteen minutes from the Affinity plant).  Nannette is an avid and excellent artist who enjoys oil painting.  She also enjoys camping trips with her husband, a former professional baseball player.  Nannette has lived in many different states and has visited every state in America except Alaska.  Nannette and Leon also had the opportunity to live in Guasave, Sinaloa Mexico when Leon played professional baseball in a winter league.

Baseball runs in the Filbeck family with their son Ryan also having played professional baseball.  In addition to Ryan, Nannette has two daughters, Amber and Andi and spends as much time as possible with her extended family while being a devoted “grandma” to her two beautiful baby grandsons.

^ back to top

 

ECG Snap Electrode Connectors


Affinity snaps with label pockets

Affinity produces a variety of ECG electrode snap and pinch connectors.  Each is designed to mate securely to a standard stud-type electrode.  Part of mating securely is mating in such as a way to not produce any unwanted noise when the pinch or snap is moved while attached to the electrode.

A snap connector is made up of the metal snap assembly which at Affinity is overmolded with thermoplastic rubber or polyurethane.  A flexible strain relief is part of the snap body and is molded over the leadwire terminated to the metal snap assembly.


Affinity’s proprietary metallic
snap assembly offers
reliable performance

Affinity uses a proprietary metal snap assembly that has been proven for over ten years to provide reliable and long lasting performance. 

The strain relief is an important part of a snap connector.  Often it must absorb the substantial perpendicular force used to disconnect the snap from the stud when the leadwire is used as a removal device.  A well designed strain relief will absorb the force over its length, preventing the force from acting on the electrical termination within the snap assembly.


One of Affinity’s standard snap
configurations with segmented strain
relief and molded-in lead designations

Affinity Medical owns a variety of proprietary snap connector and strain relief designs.  These designs will accommodate leadwires with diameters of .060, .080, .090, .100, and .120 inches accepting both shielded and unshielded leadwires as well as tinsel Kevlar wire.

Defibrillation protection is often required in medical monitoring devices.  Defib protection resistors are most commonly built into the yoke of a patient cable, however when that is not possible or desired, they may be located within the snap assembly.  Affinity offers tooling to accommodate defibrillation resistors in the snap assembly with only small lengthening of the snap.

(Insert Image: “http://www.affinitymed.com/images/news/LED%20Snaps.jpg” Caption: “Custom electrode snap with LED indicator”)


Custom electrode snap
with LED indicator

Besides standard electrode snap assemblies, Affinity produces a number of custom snaps for our OEM partners.  One unique custom product incorporates LED’s within the snap head giving the operator visual confirmation via a green light that the connection is good.

If you would like to see examples of our standard snap assemblies or discuss a custom snap, please contact Affinity Medical Customer Care at 949-477-9495 or email to customercare2@affinitymed.com.

^ back to top

 

Announcements, Information, and Trivia

Gold Discovered in California

Not today, but in 1848!  January 24th marks the anniversary of gold being discovered at Sutter’s Sawmill on the American River in Colima California.  The discovery of gold started the Gold Rush of 1849.

Early gold-seekers were called "forty-niners" and traveled to California by boat and by land, facing substantial hardships on the trip.  Besides Americans, the Gold Rush attracted tens of thousands from Latin America, Europe and Asia.  Gold was so plentiful that the first prospectors panned for gold in streams and riverbeds.


Edison’s incandescent
lamp changed the world

A few lucky prospectors became wealthy, but most returned home with little more than they had started with.

A bright Idea

Thomas Edison received the first patent for his incandescent light on January 27, 1880




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

Affinity Customer Care -
Hours of Operation

Affinity Medical Technologies customer care specialists are available to assist you from 7:00 A.M. until 4:00 P.M., U.S. Pacific Time, except holidays.

^ back to top

 

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