Medical Wire and Cable-Applications of Medical Wire

Medical wire and cable is different than wire and cable

used in other applications. Design engineers need to keep this in mind when specifying their cable. Often time custom medical cables are needed due to bio-compatibility, sterilization and possibly smaller sized device requirements.

When specifying a medical cable one needs to keep in mind several factors such as:

• Sterilization techniques autoclave, gamma, alcohol?
• Will this be a disposable cable?
• Will the cable come in contact with the patient? Bio compatibility.
• Flexibility requirements.
• How will the device be used day to day?

Due to time constraints many times engineers will sometimes settle for a readily available off the shelf cable for prototypes or proof of concept, which is fine for the short term. When it comes to field and clinical trials a prototype should be made with wire or cable specifically designed for the application to better measure longevity and functionality. Medical cable applications fall into several categories; handheld medical devices are a large segment of medical cable applications.

Medical Hand Piece Cables

Cables for medical hand pieces must carry the power, control, sensor and data to and from the hand piece. The cable may be as simple as a two-conductor cable, providing power to a cut & cauterize scalpel or a multi-conductor power, control and sensor cable used on an orthopedic surgery device. Cables for handheld medical lasers likely contain lumens for cooling. Ablating hand piece cables can also contain lumens for irrigation and suction removal.

The design of medical hand pieces falls into two categories: re-useable and disposable. See below for information on Disposable Medical Cables and Re-useable Medical Cables.

Disposable Medical Cables

Disposable medical cables are made from the lowest cost materials that will meet the design needs of the device. Conductor cost is dictated more by the number of strands used to make the conductor. The higher the strand count the more flexible the wire becomes. A marketing trade-off is often made for disposable cables, i.e. increase stiffness can be tolerated by the need to hold cost down. 7 or 19 strand conductors can be used, where in re-useable cables the strand count can be well over 50. The use of plating is reviewed and bare copper is the most often used. Tin plating is used only to enhance solder ability. Crimping the wires is often the cheapest means of terminating the conductor. Silver plating is rarely used for disposable cables. Conductor sizes are determined by the current needs of the device.

Insulation and jacket materials are chosen by cost. Low cost materials such as Poly Vinyl Chloride (PVC) or Thermo Plastic Elastomers such as poly urethane are often used. Polyethylene can be used as insulation. Insulation and jacket thickness are determined by the voltage ratings of the signals in the cable.

Shields, when required, are usually of a spiral type rather than braid to hold the cost down. Spiral shields may lose shield effectiveness during repeated flexing, but the number of flexes for disposable cables is limited.

Jacket colors usually are chosen by the program. The need for gamma sterilization may limit the color shades available. Colors can change during gamma sterilization and are usually required to be stable for less than 10 cycles to allow for re-sterilization when repackaging is needed.

Re-useable Medical Cables.

Medical cables designed for re-useable devices have to use materials that will withstand several cycles of sterilization by alcohol based agents or autoclaves.

Conductors are made from high strand count conductors for maximum flexibility and often they are made from high strength copper alloys. The size of the conductors is determined by the current they must carry to the device. To withstand the rigors of sterilization, plating’s of tin or silver plating may be required.

Insulation must also withstand the rigors of sterilization and are often either Teflon’s such as FEP, PFA or Tefzel® or Silicone Rubber. The use of lower cost materials may be made on a case by case basis.

When shields are required, they must be made from materials resistant to many sterilization cycles and are often silver plated copper or silver plated high strength copper alloys. Shield construction is usually of a braid rather than a spiral, as spiral shields can move during flexing and compromise the shielding effectiveness.

The more popular choice for cable jackets are made from Santoprene™ TPE which is good for up to 100 cycles of autoclave, or Silicone Rubber.

Medical cable applications also include implantable, medical robotics, therapeutic devices, sensors and monitoring equipment.

To find out more or discuss your applications with medical wire and cable please contact Calmont Wire & Cable.

Please feel free to leave your comments; we would enjoy hearing from you.

Medical Cable- Applications of the Lumen in the Medical Industry

In the medical device industry a lumen is a term used to describe tubing which is typically used to transfer liquids, gases/air or even other cable components such as fiber optics and cameras. Lumens can be manufactured in a variety of configurations and incorporated inside a cable with multiple lumens (multi-lumen).

If you have been to the dentist then you have had experience with lumens. The handpiece used for air and water has lumens within the cable. The suction piece placed in your mouth is a disposable lumen. Other uses for lumens include micro-surgical instruments and pressure transducers. Cables for handheld medical lasers likely contain lumens for cooling. Ablating handpiece cables can also contain lumens for irrigation and suctioning.

Lumens are not limited to the medical cable industry. Lumens are used in many industries and are often called other names such as tubing or hose.

Other industries using lumens include:

• Industrial
• Automotive
• Instrumentation and sensors
• Automation/ robotic

As products become smaller and more compact and it is more common to see tubing and cable incorporated into one component. A few examples outside the medical industry include hi-tech hand sprayers with electronic controller in handpiece, cables with hydraulic fluid tubes, pressure transducers and air controlled switches.

Often when designing a device or equipment with tubing or lumens a custom cable solution is needed. It is important to tell your cable manufacture as much information as possible about the application and its intended use.

Key information may include:

• Used for fluid, air or other?
• Will it be pressurized?
• Type of fluid or gas?
• Flexibility requirements?
• Bio-compatibility requirements?

The more your cable manufacture knows, the better the design will meet your needs. Working with a cable manufacturer early in your design phase will help to determine tubing size, material and construction to insure your project goes smoothly from the start.

Comments are welcome! Tell us about your lumen application or challenge.

Implantable silicone lumen One of the obvious benefits for using silicone wire

Silicone wire and cable is known for being extremely flexible and resistant to high temperatures, which makes it the material of choice in a variety of applications and industries that require an extremely flexible cable. Silicone wire is also flexible in the many applications and industries that it is used in. For example, Calmont is involved in a wide spectrum of projects using silicone wire and cable ranging from medical implants, automotive ignition wires to applications where the wire was weaved into fabric and even used for art and decorative lighting.

Industries that use silicone wire include:

• Medical
• Aerospace
• Robotics and automation
• Automotive

for wire and cable is the flexibility. Silicone wire, depending on the construction can be as limp as a piece of string. This type of wire is ideal with applications where routing a wire through a tight space is required such as, box builds, equipment, robotic arms or handheld devices. Other benefits include resistance to gasoline, alcohol-glycol. The temperature range for standard silicone is -60°C to 200°C and has excellent weather-ability. The downside to silicone is it's abrasion resistance which is fair. Depending on the application this may have no impact, best uses are static installations or when the wire or cable is not subject to contact with sharp objects.

Fluorosilicone is another type which is widely used and has a significantly greater chemical resistance than silicone. It is resistant to hydrocarbon fluids (gasoline / diesel) and solvents. The temperature range varies by the grade. Most is 250C it is available up to 350C upon request. Fluorosilicone also has excellent flexibility and flame retardant properties.

Tell your wire and cable manufacturer any special requirements your application has to get the right silicone compound. There are different grades, and durometers available. Sometimes a special formula or additive may be needed to meet the requirements listed below.

A few options include:

• Medical grade
• Flame retardant
• Low smoke
• High temperature to 350°C

Silicone ribbon cables are often used in place of PVC ribbon cables when flexibility is required. Silicone ribbon cables can be extruded or manufactured using a special process to bond the conductors. The construction of the silicone ribbon cable can be from two conductors to over twenty depending on the manufacturer's capabilities.

Co-extrusion: Silicone wire to the Hula Hoop.

Choosing co-extruded silicone wire for applications that require suppression of electrical noise, corona resistance, low loss of power and extremely flexible nature is ideal. The co-extrusion process for silicone wire involves the combination of two extruders running simultaneously to produce the semi conductive silicone insulation and the silicone outer jacket. There are many applications which require this type of performance.

These applications include:

• Aerospace
• Medical
• X-Ray and MRI
• Radar systems
• Photo copiers
• Robotics

Extruding the semi-conductive insulation and the outer jacket layers of silicone at the same time insures that there is no air or any contamination particles at the joining of the two layers. The use of a semi-conductive silicone layer over the copper conductor reduces corona by filling the space around the conductor with semi-conductive silicone to remove the air. The semi-conductive material also increases the effective corona inception diameter from that of one of the strands in the conductor to a diameter slightly larger than the total conductor diameter. This results in the higher corona inception values and increase effective radius of conductor found in co-extruded silicone wires.

Features and Benefits:

• Corona, moisture and ozone resistant
• Lightweight and extremely flexible design
• Radiation resistance
• Excellent electrical characteristics
• Resistant to temperature extremes
• Lower EMI

Increased Customer Benefits:

• Reduces noise on radar
• Spots on Xerox copies
• Error spots on medical x-ray's

Built in stripes

Other uses for Co-extrusion
In 1958, The Wham-O Company had a problem: The stripe in the original Hula Hoop was painted on and was wearing off quickly after a short time of use. The Wham-O Company asked Calmont Wire & Cable's founder Bill Chilcote to find a solution to the problem. Bill seized the opportunity and developed a co-extrusion process and built the equipment to add the stripe right into the tubing, which made the stripe permanent. The stripe has evolved over the years but the fundamentals of Bill’s technology are still being used today for the Hula Hoop and many other applications in a variety of industries.

Flexible Wire- Conductor and Insulation selection for flexible wire and cable

Medical device, aerospace and automation manufacturers often require flexible cables for their products. Flexible wire and cable can have many interpretations. Sometimes a simple description such as, “the wire needs to be as limp as a wet noodle” is enough to understand your needs. The choice of type of conductor and insulation can greatly influence the flexibility of the cable performance. Understanding what the flexibility requirements are will help to determine the materials and construction for the flexibility of the wire or cable.

When specifying a flexible cable you need tell your cable manufacturer what the intended use will be.

• Do you need to route it through equipment or a tight space?
• Will it be subject to repetitive flexing?
• Do you need the cable to flexible during use?

There are several factors which make a cable flexible, a few are:

• Conductor stranding
• Shield types
• Cable lay
• Insulation materials.

Typically in conductor stranding, the more strands a conductor has the more flexible the wire will be. Normally “off the shelf” wire and cable is stranded in 7 or 19 strand configurations, is not flexible enough for most applications requiring flexible or high flex cycles. The general rule is the higher the strand count of the conductor, the more flexible the wire or cable will be. Stranded conductors are composed of un-insulated “strands” of wire twisted together. The advantages of stranded conductor over a single strand are increased flexibility and flex-fatigue life. When you see 22AWG (19/34) for example, what the description means is that there are 19 strands of 34 AWG making up the 22 AWG conductor. Other common options for a 22 AWG is a single strand (solid) up to 168/44 strands. The construction of the conductor also plays a role in the cable’s flexibility, for example a rope stranding is the most flexible. For repetitive flexing applications such as robotics and automation, the use of high strand alloy material is recommended.

Choosing the right insulation can add to the cable’s flexibility. Silicone is one the most flexible of the compounds used. Silicone wire is used to meet a variety of demands such as extreme high and low temperature requirements, flame resistance, flexibility, strength and purity. The application and environment also play a role when choosing jacket material. Harsh environments, chemicals, and abrasion will narrow down your insulation and jacket options. Discussing your flexible wire application with a cable manufacturer can help you choose the right materials for the performance and longevity of your product

Finding Reliable Aerospace Products

Though it is not something most of us think about every day, some people’s livelihoods are dependent on finding high-quality aerospace products. Things like a specialty wire and cable and other materials need to be reliable and trustworthy. When you are building flying machines, you have to understand you have the lives of others in your hands. Though you need to protect your bottom line and make smart investments to save money, you also need to make safety your main priority.

Industrial wire and cable products are one of the most important investments you will make as an airplane manufacturer. If you are in charge of buying materials, you will probably have access to several different options. Your choices will not be unlimited, though. Most airplane parts and airplanes are built by one of just a few different companies. All have comparable quality and are well-known within the industry. If you have spent any length of time working in the industry, you are familiar with the companies that manufacture parts. If you should come across a company that offers parts for a deeply discounted rate, you should be skeptical of their quality.

It might be tempting to look for discounts on coaxial cables you buy in bulk. This is the common line of thinking for managers and buyers in large companies. You are always looking out for your bottom line. However, when you are dealing with an industry in which safety is a factor, the price should be secondary. Finding quality materials is your main priority. If you try to cut corners, it could cost people their lives.

Conductor flexible cables are just a few of the components you will be focused on when building an airplane. You might feel as if your attention is being pulled in several different directions. You have a lot of responsibility, but you still need to make intelligent decisions that provide you with the safest materials possible. Do your research and make sure you are making a smart choice. You can look for a good deal or buy parts from a lesser-known manufacturer, but in the long run, you are likely to regret your decision. Proceed with caution and make sure you have your priorities in order. There are plenty of ways to get great deals on parts without sacrificing quality or safety.

Custom Cable Requirements for Aerospace, Defense, And Medical Industries

Wire and cable companies have the unique privilege and responsibility of supplying materials to important applications ranging from medical fields to military defense. Common requirements of military or aerospace wire and cables include tensile strength, longevity, temperature resistance, purity of materials, conductivity, and a host of other factors. Let’s examine each of these properties that custom cables and wires must possess in order to serve the function these wires are designed to fulfill.

Tensile strength, longevity, and temperature. In the harsh, zero gravity environment of space, and the unforgiving climate conditions in parts of the Middle East, having equipment that will perform optimally despite adverse temperature, humidity, and impact damage can mean the difference between a successful mission, or the loss of human and equipment assets. In a context closer to home, a team of surgeons assisted by surgical robot machines employing high-tech robotics cables, can help a patient undergoing surgery in ways not previously possible. And it is important to the success of a surgical operation that these robotic components perform at the highest level of efficiency with regards to conductivity and strength.

Conductivity and purity of materials. This refers to the ability of custom cables to convey power and data through their medium within acceptable parameters of time taken and power transferred. For equipment to operate properly, the right amount of data or power within the allotted time required for a wide range of applications. Much of the technology employed by the medical, defense, and aerospace engineering fields run on electric power, and that power is conveyed through various lengths of wires and cables from a power source to the end of a crane’s arm or a space shuttle’s piloting console HUD display.

All these critical qualities of custom wires and cables play an integral role when operational requirements call for specified and tangible results in the context of aerospace, defense, and medical applications. And since these applications by nature have high standards of performance due to the stakes involved for each respective industry, experts in this specific field of custom cables and wires manufacturing are usually the ones who handle these requirements for NASA, government agencies, and various medical practices.

Wire Applications in Military Vehicles: H Model Cougar MRA

Applications for custom wires and cables generally fall into one of several categories, one of which being mechanical requirements for military vehicles and equipment. Military wires and cables provide electrical power, communications, and a host of other functions within a given piece of hardware.

As combat operations in Afghanistan and Iraq (Operations Enduring and Iraqi Freedom) intensified, there was a growing need for a series of vehicles designed to survive the explosive threats posed by the Improvised Explosive Devices (IEDs) as well as conventional mining and ambush tactics employed against Coalition personnel. These vehicles were collectively described as MRAP (Mine Resistant Ambush Protected) capable, and would be specifically built to defeat these threats. One such vehicle is the Cougar. Manufactured by Force Protection Inc. employing advanced flexible wire technology, the Cougar has been in production, and in service for the past seven years.

Vehicles such as the Cougar are not new designs. While new to the US military, the Cougar design can trace its origins to the Olifant Manufacturing Company of South Africa, which originally developed the multi-wheeled, "V" shaped blast hull design for use by the South African military in its operations against Angola and Namibia in the 1980s. These vehicles were designed to have good road speeds and endurance (to allow for the long distances traveled, as well as reduced maintenance requirements because of their wheeled design) and were specifically designed with advanced silicone wires and armor technologies to maximize passenger survivability against small arms ambushes and conventionally laid mines and IEDs.

The Cougar MRAP H model is a 19.4 feet long, 9 feet wide (spare tires mounted), 8.6 feet tall (not including turret splash shield.) 3-door, diesel powered, 3-ton capacity 4-wheel drive Mine Resistant Ambush Protected vehicle. The Cougar-H is The Cougar is equipped with an automatic transmission and in addition to the driver and co-driver, has seating for 4 additional passengers. Each seat is equipped with a 4-point ribbon cable shielded pur safety harness. The vehicle is equipped with driver/co-driver doors, as well as double doors for the passenger compartment, and a single vehicle accessibility hatch on the roof. The Cougar is equipped with dual A/C units (24,000/48,000 BTU/hour), is NBC overpressure and filter protected, and is equipped with a 9,000-pound capacity electrically powered winch. The unprepared fording depth is 39 inches, an approach angle of 40 degrees and a departure angle of 50 degrees. The Cougar is capable of travel both on and off road and is equipped with run-flat tire inserts. The Cougar-H is air transportable by the C-17 transport aircraft.

Requirements Information On Custom and Medical Cables

Custom cables are cables specially designed and manufactured to meet specific needs of clients. Companies that manufacture custom cables offer a whole variety of specialist services in diverse fields such as aerospace, telecommunications, radar, military, medical, industrial electronics, transportation, commercial, marine and many other fields. Custom cable manufacturers provide complete control from unique design to finished product, extremely competitive service and lead times that suit their clients. They also work with their clients to find a cost effective solution for all their clients’ custom cable needs.

High performance military wires and cables must meet the most stringent requirements for airframe defense wiring and other on-board applications. Military wire should have high temperature resistance, be small in dimension, be low weight, have low flame propagation and be mechanically tough and chemically resistant. Custom designed cables are used in radar systems, wire and special avionics cables, weapons systems cables, electronic surveillance and others. Custom military wire manufacturers develop, manufacture and market custom designed cables and cable assemblies for demanding military applications.

Aerospace cables are designed to offer optimal performance in the special conditions found in aircraft, where requirements commonly include high reliability, long lifetime, high strength, light weight and wider temperature ranges than standard telecommunications grade fiber/cable. Typical applications of aerospace cables are In-flight entertainment systems, In-flight networking systems, display systems, data transmission, communication systems, high-temperature environments and corrosive chemical environments.

Medical cables manufacturers provide medical wire for the demanding requirements of medical instrumentation. These cables provide consistent and reliable performance. The designs of medical cables utilize features that are important in health care applications. Flexibility and extended flex life, high strand counts, coolant tubes, flat cables and bonded-zip constructions, lead free insulations, coaxial composite cables, shielding and high strength conductors and shields are some of the important features provided by custom medical wire companies. Medical imaging, diagnostic instrumentation, dental x-ray machines, medical robotics, cardiac instrumentation and precision lasers are some of the fields where custom medical cables are used

Custom Cables: Quality Counts

There are plenty of jobs in the world that require some sort of cable. Because these jobs are so diverse, most hardware and home improvement stores carry all kinds of different cable. But even with this level of variety, not every cable need can be met by a local hardware store. For special jobs, it may become necessary to order flexible cables from a cable manufacturer. There are many reasons why a company might need to purchase a custom-made cable, but there aren't too many places to get cable made exactly to your specifications. That's why, when you find a good one, you've got to hold on to them.

If you need a specific type of silicone wire, then a company that makes custom cables might be able to make exactly what you need. Silicone is a great material for wire because it's heat-resistant, extremely flexible and durable, and it doesn't stick to things. If you need a special type of wire for a delicate job, then silicone is an excellent material to choose for the job. The problem is more one of finding someone who makes wire with this material than of figuring out what material you should use.

The aerospace industry is an industry that often needs custom wire and cables made. Because precision and durability are key in aerospace applications, it is of utmost importance for silicone cables to be of the highest possible quality and durability. If you skimp on cost in the aerospace industry, you're playing with people's lives just to save a few dollars. It's definitely worth the money to have custom wire made that is sure to do the job that you need done, as opposed to opting for the next-best thing or any other cheaper alternative to your first choice of material.

If you need super flexible custom cable, silicone is also an excellent choice. It bends easily and doesn't lose elasticity with movement. Some materials lose their elasticity the more you move them around, but not so with silicone. There are all different kinds of wire out in the world, and not all of them are cheap. But, in some cases, it's not about how much something costs. It's about how effective and durable that product is because a high-quality could make a life-saving difference in practice. And it's worth the money to keep people safe as they push the boundaries of what mankind can accomplish. For additional information, visit http://www.calmont.com/ to learn more.