FAQs

FAQs

Alpha® Liners - General

How should Alpha® Liners be cleaned?

What should Alpha Liner wearers do to deal with daily changes to the volume of their limbs?

What might cause an Alpha® Liner user to develop a skin irritation?

Are there any tips for traveling with Alpha® Liners?

Alpha® SmartTemp™ Liners Featuring Outlast®

How is this liner different from other liners, regardless of silicone, urethane or thermoplastic elastomer?

How does this liner work in cold temperatures?

How does this liner stop a patient from sweating?

This is a silicone liner but the details say it acts like a thermoplastic elastomer. What’s the liner durometer, or firmness, like?

Who is this liner appropriate for…or for what activity level?

Does the Alpha SmartTemp Liner retrofit with other liners?

Do these liners need to be stored differently?

What are the care instructions for the silicone of this liner?

Will the performance of the Outlast® material reduce over time?

Is this liner suitable for use with amputees who are also diabetic?

How does the Alpha SmartTemp Liner compare to the Alpha Silicone or WillowWood Express Liners?

Alpha Duo™ Liners

I noticed some oil on the exterior of the Alpha Duo Liner. Is this normal?

WillowWood Express Liners

What does ‘soft’ silicone mean and how can it replicate the feel of TPE?

What sizes other than Medium Plus and Large may be ordered in the Express Liner?

How does sizing compare between the Express Liners and the Alpha Classic and Hybrid Liners?

When will additional liner profiles be available?

Is a new socket needed in order to use an Express Liner?

Does the Express Liner have mineral oil in it?

Can amputees use mineral oil or other skin conditioners with the Express Liner?

Are lubricants or powders needed in order to don this silicone liner?

Can the Express Liner be heat-stretched?

How much testing has been done on the Express Liner?

What are the care instructions for the silicone of the Express Liner?

How should a clinician modify a shape for a vacuum socket if a patient has been cast over the Express Liner?

WillowWood has previously stated that the Original fabric now being used on the Express Liner is inappropriate for use in a vacuum environment. What makes it OK to use it now?

How much does the WillowWood Express Liner, made of silicone, weigh in comparison to an Alpha Classic or Hybrid Liner that was made of TPE?

Feet

What makes the Pathfinder® II different from other feet?

Which prosthetic foot is best for a particular patient?

LimbLogic®

Do you offer training courses on LimbLogic?

Can LimbLogic be used with Thermoplastic Sockets?

What comes in a LimbLogic box?

What comes in the Thermoplastic Drop-in Adapter kit?

To fabricate a thermoplastic LimbLogic socket, do I need a tooling kit?

How many applications are available from the Resin Kit that comes with the Thermoplastic tooling kit?

Is LimbLogic waterproof?

What changed from the old unit to the new LimbLogic unit?

Is LimbLogic safe to use if a patient has a defibrillator or pacemaker?

Can the LimbLogic VS 1600 series be used in water?

What is the warranty for the LimbLogic?

Is there a trial period for the LimbLogic?

How much does the LimbLogic vacuum pump weigh?

What is the battery life for the LimbLogic?

Are any special procedures required for fabricating a socket for use with LimbLogic?

When using the LimbLogic, does the socket need to be sealed?

What type of maintenance is required for LimbLogic?

What are the LimbLogic system settings?

What type of liners should be used with the LimbLogic?

How do I convert from inches of mercury (in-Hg) to millimeters of mercury (mm-Hg)?

How does vacuum suspension work?

What is the difference between suction suspension and vacuum suspension?

What L-codes are suggested for the LimbLogic system?

What is the torque required to attach the LimbLogic pump to the prosthesis?

What is the difference between the System Maximum, the User Maximum, and the Upper Set Point?

Pediatric

Does WillowWood make prosthetic components for children?

What is the difference between the Pediatric SACH Foot and the Pediatric  Impulse® Foot?

Suspension

When should a suspension sleeve (or seal) be worn?

Which type of suspension is best – suction, vacuum, or locking pin?

General

I am an amputee. Can I buy directly from WillowWood?

Does weight gain or weight loss impact the comfort of a lower extremity prosthesis?

Can you recommend an amputee support group?

In addition to support groups, are there any additional resources for parents of amputees?

How do I find the best prosthetist for me?

What can an individual do to ensure that a prosthesis is covered by medical insurance companies?

Some amputees wear cosmetic coverings over their prostheses and others don’t. Is there any reason for wearing a covering or not?

Plaster casting is so messy and time-consuming. Are there any alternatives?

Answers

Alpha® Liners - General

How should Alpha® Liners be cleaned?

At the end of the day, wash the liner with water and a body soap that does not irritate the skin. Allow the liner to dry on the drying stand overnight. Once a week, disinfect the liner by wiping the gel with ethyl or isopropyl alcohol and allowing the liner to dry overnight.

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What should Alpha Liner wearers do to deal with daily changes to the volume of their limbs?

  • Examine Alpha® Liners daily. Report any signs of unusual wear to your prosthetist.
  • Apply volume management pads, 3mm-thick, on the limb in the area where volume has been lost – for example, at the back of the leg for a BK amputee.
  • Avoid the use of socks, which increase the volume symmetrically (not just in the places where volume has been lost).
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What might cause an Alpha® Liner user to develop a skin irritation?

  • Although our Alpha® liners have proven to be very skin-friendly for most amputees, we do occasionally hear reports of skin irritations. Possible causes:
  • Not cleaning the liner daily. Neglecting to clean the liners daily may cause a rash to occur on the residual limb due to a buildup of bacteria from the skin.
  • Not rinsing all the soap off the liner. Soap residue may cause an irritation to develop.
  • Not drying the liners correctly. Drying the liner gel side out (instead of gel side in) can damage the liner and can allow dirt to stick to the gel, which can lead to skin irritation.
  • Not disinfecting the Alpha Liner with alcohol every week. If a rash appears after two or three months of using an Alpha Liner, this is the likely cause. Note: using an anti-bacterial soap instead of alcohol is not an effective means of disinfection
  • Use of a harsh or irritating soap, lotion, or cream. Use the same soap on the liner that is used in the bath or shower. Do not use talcum powder, or any creams or lotions that contain animal fats or oils (lanolin, vitamin E oil, etc.) or hydrocarbon oils (petroleum jelly, silicone oil, etc.).
  • Pulling the liner onto the limb instead of rolling it on. Some amputees will grab the top edge of the liner and try to pull it as high on the leg as possible, like putting on a boot. This can lead to irritation along the top edge of the liner. Be sure to roll the liner onto the limb without pulling.
  • Gouges, holes or other damage on the gel surface. Cleaning the gel by scrubbing it instead of wiping it gently can cause damage.
  • Liner is loose. If a liner is too big, or if the limb has shrunk, air can get trapped between the skin and the liner. This can result in excessive sweating that can lead to a rash. Also, a liner that is too loose allows the limb to rub back and forth on the liner. Try applying volume management pads to the area that has shrunk.
  • An allergic reaction. Though we’ve never had a documented case of an allergic reaction to the Alpha gel, it’s possible. To rule this out, put a clean piece of Alpha gel somewhere else on the body for a few days to see if the skin reacts the same way.
  • Fungal and/or bacterial infection. This will require treatment from a dermatologist.
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Are there any tips for traveling with Alpha® Liners?

  • Trim the drying stand to a shorter length to make it easier to fit in a suitcase.
  • When packing a liner in a suitcase, put some socks or a t-shirt in a plastic bag and roll the liner over it.
  • To dry a Locking Liner without having to pack a drying stand: take a shoe string (or other similar string), tie a slip knot on both ends, slip one knot over a coat hanger, slip the other end around the pin on the end of the liner, and hang the liner to dry.
  • Avoid leaving Alpha Liners in hot places (like the trunk of a car), because the heat can deform the liner.
  • Pack some volume management pads to help deal with daily volume fluctuations.
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Alpha® SmartTemp™ Liners Featuring Outlast®

How is this liner different from other liners, regardless of silicone, urethane or thermoplastic elastomer?

The Alpha® SmartTemp™ Liner uses Outlast® technology to pull heat away from an amputee’s limb throughout the day as well as during times of high-activity or elevated temperature. To help illustrate this, think of a sponge. When dry, a sponge is firm to the touch. When placed in water, a sponge soaks up the water until is it completely saturated. Once all the water is absorbed by the sponge, over a period of time the water evaporates out of the sponge and it returns to its dry state. The Alpha SmartTemp Liner with Outlast® goes through the same basic cycle, but with heat rather than the water in our sponge example. The length of time it takes for all the absorbed heat to be released can vary depending on a person’s environment and if the liner is left on a residual limb or removed.

The Alpha SmartTemp Liner also differs from other liners in regards to its firmness. Using the same sponge example as above, the dry sponge is firm to the touch. As the sponge absorbs water, it becomes softer to the touch and more flexible. After the water is removed from the sponge and it dries, the sponge returns to its firm state. The Alpha SmartTemp Liner with Outlast® responds similarly to heat as it is absorbed and stored in the liner. The silicone of the liner is firm before it is donned onto a residual limb. As the liner absorbs heat, the silicone properties begin to act more like thermoplastic elastomer. When the liner is removed from a limb or an amputee moves to a cooler environment, the stored heat is released and the silicone reverts back to its normal state.

At any activity level, the Alpha SmartTemp Liner absorbs heat while on an amputee’s limb creating a comfortable skin temperature level by balancing the amputee’s skin temperature and the liner temperature. The liner though can become saturated with heat and can reach a point at which it can no longer absorb more heat. Once the liner is saturated with heat it needs to be cooled back to room temperature and return to its normal state. After the liner is cooled, which could be achieved by doffing the liner and letting it rest or by going into a cooler environment such as an air-conditioned building, it will once again be ready to absorb and store heat.

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How does this liner work in cold temperatures?

The Alpha SmartTemp Liner with Outlast® works the same in warm or cold temperatures. The liner will absorb heat from the residual limb to create a comfortable skin temperature. However, the colder the environmental temperature, the quicker the liner dissipates the absorbed heat.

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How does this liner stop a patient from sweating?

The technology in the Alpha SmartTemp Liner does not stop sweating. The Outlast® material that is included in the liner will delay the onset of sweating and should delay patients from excessively sweating. During clinical testing, several amputees reported they could wear the liner 14 to 20 hours without having to remove the Alpha SmartTemp Liner, pour out the accumulated sweat, dry their limbs and liners, then re-don the liners. By incorporating Outlast® with the silicone, the liner absorbs heat from a person’s limb and environment, stores it in the liner, and delays sweat from starting.

Every amputee is different. A person’s activity level, environment, and personal metabolism are all variables that contribute to how long the onset of sweat is delayed. This can vary for each individual yet all amputees who wear the liners will realize the benefits of the liner technology.

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This is a silicone liner but the details say it acts like a thermoplastic elastomer. What’s the liner durometer, or firmness, like?

The Alpha SmartTemp Liner is a silicone and has a durometer similar to our Alpha Silicone Liners. By incorporating Outlast® with the silicone, the liner absorbs heat from a person’s limb and environment and stores it in the liner. Once the Alpha SmartTemp Liner is donned, has absorbed heat, and is warm, the liner durometer then is similar to that of thermoplastic elastomer, or gel liner. The liner actually becomes more comfortable throughout the day as it is worn.

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Who is this liner appropriate for…or for what activity level?

The liner is suitable for any activity level. Amputees who regularly experience mild/moderate perspiration or discomfort from heat or sweat are candidates for the Alpha SmartTemp Liner. Additionally, amputees who currently wear silicone and like its durability yet desire a more comfortable interface are also be appropriate candidates for this liner.

However, amputees with fragile or highly-sensitive skin may not be best suited for Alpha SmartTemp Liner.

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Does the Alpha SmartTemp Liner retrofit with other liners?

Yes! Any liner with WillowWood’s progressive or symmetrical AK profiles will retrofit with the Alpha SmartTemp Liner. Alpha Classic Liners, Alpha Hybrid Liners, and Alpha Silicone Liners with progressive profiles will retrofit with an Alpha SmartTemp Liner with a progressive profile. Likewise, an Alpha Classic AK Liner, Alpha Hybrid AK Liner, or Alpha Silicone AK Liner with a symmetrical AK profile will retrofit with the Alpha SmartTemp AK Liner.

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Do these liners need to be stored differently?

No, Alpha SmartTemp Liners may be stored the same as other Alpha Liners.

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What are the care instructions for the silicone of this liner?

The care instructions for this liner have not changed. At the end of each day, wash the liner with water and a body soap that does not irritate the skin. Allow the liner to dry on the drying stand overnight. Once a week, disinfect the liner by wiping the interior with ethyl or isopropyl alcohol and allowing the liner to dry overnight.

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Will the performance of the Outlast® material reduce over time?

No, Outlast® does not degrade over time.

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Is this liner suitable for use with amputees who are also diabetic?

The Alpha SmartTemp Liner is suitable for a variety of patients. Several of our test patients who participated in clinically testing this liner were diabetics. These patients had healthy residual limbs and experienced no problems with the Alpha SmartTemp Liner. The decision to use this liner on diabetic amputees is up to an individual’s clinician. An amputee’s lifestyle/activity level, environment, and metabolism as well as skin sensitivity should be considered in clinical decision-making.

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How does the Alpha SmartTemp Liner compare to the Alpha Silicone or WillowWood Express Liners?

All of these liners use a proprietary, platinum-cured, medical grade silicone. The liners do share some common traits such as profiles and fabrics yet they also each have unique characteristics.

WillowWood Express Liner is a softer-durometer silicone that replicates the feel and comfort of thermoplastic elastomer (gel) liners. The profiles of this liner are uniform for transtibial use and AK for transfemoral use. Original or Select fabrics are used for transtibial liners and Spirit or MAX fabrics are used for transfemoral liners.

Alpha Silicone Liner is unique blend of silicone, Vitamin E, and skin conditioners with a surface that is non-greasy and comfortable against the skin. The profiles for this liner are progressive for transtibial use and Symmetrical AK for transfemoral use. The Alpha Silicone Liner uses the one-way stretch Select fabric to control pistoning.

Alpha SmartTemp Liner featuring Outlast® is the only liner in the WillowWood product line, as well as within the industry, that blends silicone with Outlast®, the original heat management technology. The liner absorbs heat from the residual limb, stores it, then releases the heat as the liner cools, thereby delaying the onset of sweat and helping an amputee stay comfortable throughout the day. The profiles for the Alpha SmartTemp Liner are progressive for transtibial use and Symmetrical AK for transfemoral use and can retrofit with any Alpha Liner having these same profiles. The liner uses Select fabric.

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Alpha Duo™ Liners

I noticed some oil on the exterior of the Alpha Duo Liner. Is this normal?

The Alpha Duo Liner combines Alpha Classic® Gel, with mineral oil, on the interior with Alpha Silicone® on the exterior into one liner. Temperature fluctuations of the Alpha Duo Liner may cause mineral oil from the Alpha Classic Gel to migrate to the exterior liner surface.

Should this occur, a replacement liner is not needed. Simply wipe the liner exterior to remove the mineral oil. You may then proceed with donning the liner as usual.

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WillowWood Express Liners

What does ‘soft’ silicone mean and how can it replicate the feel of TPE?

We’ve adjusted the silicone formula used in our Alpha Silicone Liners in order to create what can best be described as a ‘soft’ silicone. This means that the durometer of the soft silicone is much less than the silicone in our Alpha® Silicone Liners.

The silicone of the Express Liner is soft to the touch and exhibits some performance characteristics common to our Alpha Classic Gel. For example, the soft silicone in the Express Liner flows away from high-pressure areas yet rebounds back to its original shape like that of silicone.

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What sizes other than Medium Plus and Large may be ordered in the Express Liner?

We have broadened the product offerings for the Express Liner since its initial release. We are working to expand into additional options as quickly as possible. Please check the product page for updates or call our customer care team at 800.848.4930 for the latest.

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How does sizing compare between the Express Liners and the Alpha Classic and Hybrid Liners?

We’ve kept sizing simple. The size worn in an Alpha Classic or Alpha Hybrid is the same size an amputee would wear in the Express Liner. If an amputee wore an M+ Alpha Classic Liner with a 6 mm, uniform profile, they would wear an M+ WillowWood Express Liner with 6 mm, uniform profile.

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When will additional liner profiles be available?

We are working to expand into other profiles as quickly as possible. Please check the Express Liner product page for updates or call our customer care team at 800.848.4930 for the latest.

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Is a new socket needed in order to use an Express Liner?

For amputees currently wearing a 6 mm, uniform profile Alpha Classic or Alpha Hybrid Liner it should not be necessary to make a new socket if switching to an Express Liner. In our clinical testing, our test patients were able to be retrofitted into the Express Liner and continue to use their existing sockets.

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Does the Express Liner have mineral oil in it?

No, however our blend of silicone used in the Express Liner includes Vitamin E as well as a skin-friendly emollient that is light, non-greasy, and moisturizing.

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Can amputees use mineral oil or other skin conditioners with the Express Liner?

Our recommendation would be to use mineral oil or desired skin conditioner overnight rather than when wearing the liner.

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Are lubricants or powders needed in order to don this silicone liner?

No lubricants, oils, or powders of any kind are needed in order to don the WillowWood Express Liner.

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Can the Express Liner be heat-stretched?

If the Express Liner has Original Fabric, it may be heat-stretched. We have tested heat-stretching the Express Liner in Original fabric. It may be done with a slight gain in patient fit. If you wish to heat-stretch, please click here for instructions. Heat-stretching so NOT recommended for Express Liners that have Select Fabric.

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How much testing has been done on the Express Liner?

We’ve conducted both mechanical and clinical testing on the Express Liners. Performance of the liner has consistently performed at levels comparable to our Alpha Classic Gel throughout our gamut of mechanical tests. Clinically, all Express Liners have successfully retrofitted with existing sockets of our test patients. Additionally, we have previously conducted biocompatibility testing on the elements used in this silicone formula and no concerns were reported.

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What are the care instructions for the silicone of the Express Liner?

The care instructions for this liner have not changed. At the end of the day, wash the liner with water and a body soap that does not irritate the skin. Allow the liner to dry on the drying stand overnight. Once a week, disinfect the liner by wiping the gel with ethyl or isopropyl alcohol and allowing the liner to dry overnight.

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How should a clinician modify a shape for a vacuum socket if a patient has been cast over the Express Liner?

Volume reductions are consistent with those previously done with Alpha Classic and the Alpha Hybrid Liners.

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WillowWood has previously stated that the Original fabric now being used on the Express Liner is inappropriate for use in a vacuum environment. What makes it OK to use it now?

It is what is on the inside of a liner that makes the primary difference rather than the fabric. Alpha Classic Liners with Original fabric were composed of thermoplastic elastomer which contained mineral oil. Our testing had found that mineral oil would ‘leech’ through the Original fabric and into the vacuum pump.

The Express Liner uses our soft silicone which contains no mineral oil. This makes the liner, with the Original Fabric, compatible for use with elevated vacuum.

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How much does the WillowWood Express Liner, made of silicone, weigh in comparison to an Alpha Classic or Hybrid Liner that was made of TPE?

Expect this silicone liner, of equal volume, to be about 25% heavier than an Alpha Classic or Hybrid Liner that was made of TPE.

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Feet

What makes the Pathfinder® II different from other feet?

Unlike any other foot, the Pathfinder II features a toe spring, a foot plate, and a pneumatic heel spring all connected in a triangular configuration. This design provides shock absorption during heel strike without diminishing the energy return of the toe spring. The result is a foot that requires less energy for walking or running, yet provides excellent balance and stability.

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Which prosthetic foot is best for a particular patient?

Every amputee is different, and every amputee has different needs. Amputees must talk to their prosthetists about their pre-amputation activity level, their current activity level, and the activity level they hope to achieve. Foot weight, energy return, and response must also be discussed so that the prosthetist can select a foot that matches the amputee’s needs.

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LimbLogic®

Do you offer training courses on LimbLogic?

We offer courses for prosthetists at our Education Center. Visit our Calendar of Events to view course offerings or call 1.877.665.5443.

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Can LimbLogic be used with Thermoplastic Sockets?

Yes. When ordering LimbLogic, be sure to specify that a thermoplastic socket will be used so that the correct adapter will be shipped.

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What comes in a LimbLogic box?

Each single-unit box includes a LimbLogic pump, a hand-held fob, a lamination kit OR a thermoplastic fabrication kit, a patient accessory kit, the patient and prosthetist manuals, a battery charger, and an international power plug.

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What comes in the Thermoplastic Drop-in Adapter kit?

A drop-in adapter, a Poron Filter, four M6 x 55 screws, a ¼ x 20 Cap Screw, a Plastic Anchor, a Latex Form, and two Forming Sleeves (one large, and one small). The kit also includes a fabrication instructional video.

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To fabricate a thermoplastic LimbLogic socket, do I need a tooling kit?

Yes, a one-time purchase of a Thermoplastic Tooling Kit (LLV-02100) is required.

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How many applications are available from the Resin Kit that comes with the Thermoplastic tooling kit?

You should get 6-8 applications from the resin in the kit. Additional resin is available by the gallon (LLV-02102).

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Is LimbLogic waterproof?

The current version of the LimbLogic pump (the 2000 series that is round in shape) is waterproof for FRESH WATER only to a depth of 3 meters (10 feet) for up to 12 hours at a time. The hand-held fob is NOT waterproof and should not get wet.

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What changed from the old unit to the new LimbLogic unit?

LimbLogic now has a round 4-hole controller design with field-serviceable exhaust filter and inductive charging. The product also utilizes a small, convenient, Bluetooth® Low-Energy remote.

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Is LimbLogic safe to use if a patient has a defibrillator or pacemaker?

WillowWood’s LimbLogic products have been designed, manufactured, and tested to operate properly when used in proximity to other products that have been properly designed and tested.

 

WillowWood does not know how non-WillowWood medical products are made or how other companies choose to monitor, power, or connect to their devices. As such, WillowWood cannot determine how use of WillowWood products might affect other products.

 

Determinations of susceptibility for non-WillowWood devices must be made by the companies that manufactured the product in question. 

 

When asking other companies about compatibility with the LimbLogic products, the following information may be of help to these companies.
  1. The LimbLogic pump and its accessories were designed and manufactured in accordance with medical electrical standards including IEC 60601-1 and IEC 60601-1-2 ed 3.0.  As such, its emissions are within the acceptable range for a medical product. LimbLogic products and accessories pass all FCC, CE, and Industry Canada standards for exposure and comply with the guidelines of the ICNIRP.
  2. Emissions from the charger are probably the most likely to be of concern. The power emitted from a powered charger which has been unplugged from the pump is low, largely confined to a few millimeters from the charger tip, and compliant with all relevant regulations and guidelines.  However, the LimbLogic charger is an inductive charger, and as such, an FCC Class B intentional radiator. The center frequencies for the charger are 42 kHz and 84 kHz.
The most relevant sections of our manual for discussion with another supplier will be:
  1. “Guidance and Manufacturer’s Declaration – Electromagnetic Emissions.”  This lists the basic emissions standards that we comply with, for both the pump, the charger, and the fob.
  2. “FCC AND IC COMPLIANCE INFORMATION” This mentions that the charger is a Class B device.  In other words, it intentionally radiates power. The power carrier frequencies are 42 kHz and 84 kHz.  We pass ICNIRP, FCC, CE, and Industry Canada standards for exposure.
  3. We used a certified Bluetooth Low Energy module.
  4. There is also the warning “Electrical equipment can interact. Do not operate the fob, charger, or either LimbLogic pump design while they are stacked upon, or in close proximity to, other electrical equipment without monitoring performance. Doing so may result in equipment malfunction or failure.”

Again, the LimbLogic product line complies with relevant medical products safety guidelines and can be expected to function properly in proximity to other electrical devices.  However, WillowWood cannot know how another company’s devices are made and therefore cannot make a judgement as to how they will function in proximity to a LimbLogic device. If it would be helpful, with prior notice, WillowWood would be happy to talk with other manufacturers with regards to their products.

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Can the LimbLogic VS 1600 series be used in water?

LimbLogic VS has been water resistant since the product was launched in 2007. If a patient was in a wet environment, the LimbLogic VS was usually not at risk. In 2009, LimbLogic pumps became waterproof in FRESH WATER only to a depth of 3 meters (10 feet) for up to 12 hours at a time. Today, every LimbLogic pump is waterproof for fresh water.

The hand-held fob is NOT waterproof and should never get wet.

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What is the warranty for the LimbLogic?

Two years. Damage from misuse is not covered.

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Is there a trial period for the LimbLogic?

Yes, there is a 30 day trial period.

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How much does the LimbLogic vacuum pump weigh?

The distal-mount LimbLogic pump weighs 225 g.

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What is the battery life for the LimbLogic?

The pump’s battery life depends on the quality of the seal and the amputee’s activity level. Our tests show that the system can normally last between 1 day and 1 week on a patient. We recommend charging the unit daily.

The fob uses a commercially available CR2032 coin cell battery. The battery will normally have to be replaced every 3 months depending upon how much the fob is used.

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Are any special procedures required for fabricating a socket for use with LimbLogic?

Yes. An airtight socket is critical to proper operation of the overall system. We recommend specific fabrication methods to achieve airtight sockets. These methods are included in the kit instructions, are available on our website, and are taught in our training classes.

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When using the LimbLogic, does the socket need to be sealed?

Yes. An airtight sealing sleeve in normally required, but there may be other methods for achieving a good vacuum seal.

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What type of maintenance is required for LimbLogic?

Keep debris away from the filter in the socket. Do not  use in corrosive environments, such as salt water.

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What are the LimbLogic system settings?

The vacuum is adjustable from 0 to 20 in-Hg (508 mm-Hg) with most BK patients using a 10 to 16 in-Hg upper set point. The default control range is a span of 6 in-Hg.

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What type of liners should be used with the LimbLogic?

Our tests show that the best compatibility with vacuum is provided by Alpha Silicone or Alpha SmartTemp Liners. If patients prefer gel liners, we suggest the Alpha Hybrid Liner with the Progressive gel pattern. You can use the Uniform gel pattern if you like, but the top edge tends to be bulky when it’s reflected.

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How do I convert from inches of mercury (in-Hg) to millimeters of mercury (mm-Hg)?

The LimbLogic System displays vacuum settings in inches of mercury. To convert from inches of mercury to millimeters of mercury, multiply by 25.4.

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How does vacuum suspension work?

A negative air pressure is created between the outside of a fabric-coated liner and an airtight socket when the vacuum pump pulls the air from the between the liner gel and socket wall. The negative air pressure pulls the liner towards the wall of the socket. The liner gel creates a similar airtight seal to the limb, so when the liner is pulled towards the socket, the limb is held firmly in place.

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What is the difference between suction suspension and vacuum suspension?

Both methods use a difference in atmospheric pressure to attach the socket to the residual limb. But because suction suspension uses a passive expulsion valve to allow air to leave the socket, a negative pressure differential is only created when the limb begins to move. The active pump used in vacuum suspension doesn’t depend upon the limb position.

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What L-codes are suggested for the LimbLogic system?

L-5781 for the vacuum pump is the suggested L-code.

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What is the torque required to attach the LimbLogic pump to the prosthesis?

The M6 flathead screws provided should be tightened to 9 ft-lbs or 12 Nm of torque.

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What is the difference between the System Maximum, the User Maximum, and the Upper Set Point?

  • The System Maximum is 20 in-Hg, which is the highest vacuum setting that is possible with the pump hardware.
  • The User Maximum is set by the prosthetist as the maximum vacuum level that should be applied to the limb. The User Maximum cannot be set higher than the System Maximum.
  • The Upper Set Point is the highest vacuum level that will be automatically maintained by the pump. It can be adjusted by the amputee, but cannot be set higher than the User Maximum.
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Pediatric

Does WillowWood make prosthetic components for children?

Our pediatric product line includes feet, durable Alpha® Liners, and tough components…even a growth kit for accommodating growth spurts.

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What is the difference between the Pediatric SACH Foot and the Pediatric  Impulse® Foot?

The pediatric SACH Foot is a basic foot that is intended for children who are not mature walkers (when they walk, the heel may not come into contact with the ground at all). The pediatric Impulse Foot is intended for children whose gait has matured to the point where they can benefit from more advanced foot function.

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Suspension

When should a suspension sleeve (or seal) be worn?

A suspension sleeve should be worn with any kind of suction or vacuum socket to prevent air from entering the socket after it has been expelled. WillowWood offers the LimbLogic Sleeve for use with either vacuum sockets or suction sockets (or with locking sockets if a little additional security is desired).

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Which type of suspension is best – suction, vacuum, or locking pin?

What works best for one amputee might not be what works best for another, but here are some of the pros and cons of each method:

  • Locking Pin Suspension
    Locking pin suspension, in which a pin on the bottom of liner fits into a lock in the bottom of the socket, gives many amputees the feeling of a secure suspension. It is also generally the easiest of these three methods to don and off. The main disadvantage is “pistoning”, which is when the liner and limb stretch out within the socket while the leg is swinging forward due to daily volume fluctuation. Also, the pin must be centered exactly within the lock, which can be hard for amputees who have poor eyesight.
  • Suction Suspension
    Suction suspension holds the limb secure because air in the socket is forced out through a valve at the bottom of the socket, creating a vacuum effect. Pistoning is not an issue, because the weight of the prosthesis is not focused on one small point at the bottom of the socket. Also, there’s no need to line up a pin with a lock. However, a suspension sleeve is required to prevent air from entering the socket, which adds a little bit of weight and bulk.
  • Vacuum Suspension
    Vacuum suspension, like suction suspension, uses a difference in atmospheric pressure to attach the socket to the residual limb. But because suction suspension uses a passive expulsion valve to allow air to leave the socket, a negative pressure differential is only created when the limb begins to move. The active pump used in vacuum suspension doesn’t depend upon the limb position. A disadvantage is that this type of suspension requires more maintenance (battery charging, system flushing, etc.) than the others.
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General

I am an amputee. Can I buy directly from WillowWood?

No. Because the selection and fitting of WillowWood products require the technical and clinical knowledge possessed by certified prosthetists, we do not sell any of our products directly to amputees. If you are interested in one of our products, talk to your prosthetist to see if it might be suitable for you.

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Does weight gain or weight loss impact the comfort of a lower extremity prosthesis?

Yes. A gain or loss of more than 10 pounds can result in discomfort, change in gait, skin breakdowns, and stress on other parts of the body, and should be reported to the prosthetist so that appropriate adjustments can be made.

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Can you recommend an amputee support group?

While we do not recommend support groups, we can suggest the following sources for information:

  • Ask your prosthetist or look for information in their office’s waiting area
  • Ask other amputees for recommendations
  • Search online for the closest group
  • Contact the Amputee Coalition at 888-267-5669 or go to http://www.amputee-coalition.org/npn_group_list.html for a list of amputee support groups that are registered with the National Limb Loss Information Center.
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In addition to support groups, are there any additional resources for parents of amputees?

The Amputee Coalition holds summer camps for young amputees ages 10 through 17. Find out more at http://www.amputee-coalition.org/youth_camp.html.

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How do I find the best prosthetist for me?

While we do not recommend specific prosthetists, we can suggest the following sources for information:

  • Other amputees: Suggestions from amputees who have amputations similar to yours can be especially helpful.
  • Amputee Support Groups: Support groups can be helpful resources for just about every situation an amputee faces. For a listing of Amputee Coalition member support groups in the US, visit http://www.amputee-coalition.org/npn_group_list.html
  • Your physician and/or hospital staff: Hospital staff members, including surgeons, physical therapists, nurses, and staff social/family workers may all be sources for suggestions.
  • Amputee Coalition: Call the Amputee Coalition at 888-267-5669 for a wealth of information to amputees on choosing a prosthetist.
  • The American Board for Certification in Orthotics and Prosthetics, Inc. (ABC) and the Board for Orthotist/Prosthetist Certification (BOC): The ABC and BOC are the two national boards that certify prosthetists and orthotists. Both organizations offer search features on their websites for locating prosthetists by city, state, zip code, or name. Contact ABC at www.abcop.org or 703-836-7114. Contact BOC at www.bocusa.org/how-choose-practitioner or call 877-776-2200.
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What can an individual do to ensure that a prosthesis is covered by medical insurance companies?

  • Educate yourself: Take time to carefully review what your insurance covers, what requirements must be met, and if there is a lifetime maximum for any procedures or equipment.
  • Choose the plan best suited for you: Do your research of what options your employer or private insurance agent offers and select the plan that best suits your needs.
  • Take charge: Check with your employer’s human resource or benefits manager to see how your needs can be expressed when negotiating for new or renewal of the company’s insurance plan(s).
  • Don’t give up easily: When a medical claim has been declined, insurance companies do provide an appeals process.
  • For more information, contact the Amputee Coalition at 1-888-267-5669 or visit their website at www.amputee-coalition.org.
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Some amputees wear cosmetic coverings over their prostheses and others don’t. Is there any reason for wearing a covering or not?

This is a very personal decision. Some amputees want to blend in, while others don’t mind if anyone sees their prostheses. There are many options available, ranging from fairly simple to highly customized. Talk to other amputees or to your prosthetist for more insight on this matter.

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Plaster casting is so messy and time-consuming. Are there any alternatives?

WillowWood offers the OMEGA® System, which allows clinicians to capture the shape of a limb electronically for the creation of a socket, a custom liner, or an orthosis.

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