New Applications of CAD/CAM
September 2008 Issue
The integration of computer aided design and manufacturing (CAD/CAM) has been around for five decades. The technology, which was originally developed in the mid-1950s for use in the U.S. military, quickly spread to use by the automotive industry. As the technology grew in sophistication, so did its applications. Today, CAD/CAM technology is being used to manufacture everything from fine china and jet propulsion systems to-you guessed it-orthotic and prosthetic devices. Patients are already benefiting from digitally designed and created cranial helmets, AFOs, and multiple other orthotic applications, all or most of which have been made possible by the laser scanner, which has changed the way shapes are captured and enabled immense progress in the ways O&P practitioners are able to care for their patients.
New developments in CAD/ CAM continue to dazzle us as they debut. Chief among those, according to Randy Alley, BSc, CP, CFT, FAAOP, are contributions to upper-limb design. Alley is chair of the American Academy of Orthotists and Prosthetists (the Academy) CAD/CAM Society, which recently provided templates for the newer upper-limb interface designs to the industry's leading CAD/CAM providers.
|Body jakcet design. Photograph courtesy of Vorum Research Corporation.|
Despite the impressive and growing array of CAD/CAM capabilities, innovations are not being embraced and utilized as universally as one might expect-an issue that Alley aims to address. The problem is not that amazing capabilities aren't available to the industry, but rather that many potential users aren't aware of or can't afford them. Alley has developed a four-step plan to spread the CAD/CAM gospel to more who might benefit from its use:
- Education : Compile an easily understood and readily accessible directory detailing which CAD/CAM capabilities are currently available from which systems, who is providing them, and what they cost. Alley's goal is the development of a website that can be easily updated with the latest developments in the field as they are introduced.
- Reimbursement : Justify increased reimbursements for CAD/CAM use. "If we can show that there are improved outcomes because of CAD/CAM, then I think there's a strong argument that it should be reimbursable," Alley says.
- L-Codes : Assist with the assignment of L-Codes to identifiable and quantifiable CAD/CAM processes, such as the use of imaging devices, templates, digital exchange of information, and incremental changes in volume by percentages. "All those things are definable," Alley says. "We just have to make the effort to do so."
- CAD/CAM Society Membership : Increased membership in the society will increase awareness as well as the society treasury, thereby enabling faster progress toward the above-mentioned goals.
|Cranial remolding orthosis functionality. Photograph courtesy of Ohio Willow Wood.|
Alley's program is still in the early implementation phase, beginning with a direct survey of CAD/CAM manufacturers, the results of which will be available soon.
Meanwhile, CAD/CAM technology and fresh and insightful ways to tap its potential continue to develop:
Scoliosis consultant Jose Miguel Gomez, T. MD, LO, discovered years ago that CAD provides an easy, reliable, and consistent method for modifying and designing custom orthoses for his patients. He now uses CAD to develop custom orthotic solutions for 99 percent of his scoliosis and spinal deformity patients and rarely uses plaster molds. The Gomez Orthotic System begins with a careful evaluation of the patient's deformity in the coronal, sagittal, and transverse planes, documented with digital photos. "The key is determining the plane of most involvement, quantifying it in percentage of flexibility or correct-ability in each plane," Gomez says. "Only then can we begin to design the appropriate orthosis. Our goal is to help the clinicians to better understand the patients needs through the use of new tools."
|Cranial implant creation. Photograph courtesy of SensAble Technology.|
Those new tools have been appearing at ever-greater levels of sophistication over the last two decades.
The Evolution of CAD/CAM
"When CAD/CAM came out 20 years ago, capabilities were limited, partially because of computer technology?' remembers Mark Mazloff, vice president and chief engineer of BioSculptor®, Hialeah, Florida. "Now there really isn't any body part you cannot scan. We have many different ways to bring a model into the computer, like our BioScanner™, which is a twin-head laser scanner, non-contact solution.
Included on its list of new orthotic capabilities are cranial helmets, manufacture of which requires pre-market approval from the U.S. Food and Drug Administration (FDA). (BioSculptor has applied for the mandatory premarket notification, the 510k).
Richard Hughes, technical-clinical training, BioSculptor, says he has seen an increase in CAD/CAM interest over the past year. "We have so many different ways of bringing information in-via scanner or imager or through hospital-based CT [computer tomography] or MRI [magnetic resonance imaging] equipment. That's an idea that's been in development for a long time, but now there's more interest in where we're going with it. We can download CT and MRI data into the BioSculptor program and create the 3-D model from that as well.
What makes this process advantageous and attractive, points out Alan Finnieston, CPO, BioSculptor's president, is that in many cases, such as spinal trauma, the CT and MRI scans already exist in the patient's hospital records, so no secondary impression is necessary. BioSculptor's technology can use existing scans to create and return a three-dimensional model to the practitioner-to be used just as if the practitioner had taken a cast.
The new scanning technology has made it possible for BioSculptor to write a number of requested custom applications. "We've done a special custom liner system, wheelchair rehabilitative-seating systems, foot systems, knee braces, and applications that are specific to other industries," Finnieston says, adding that the applications are limited only by the user's creativity.
BioSculptor has also created an Internet portal ( www.noplaster.com ) that Finnieston describes as "international one-stop shopping, where anybody in the world can send in a digital file or can order their materials, component parts, anything they want. We're using an open forum that allows a prosthetist or orthotist to do business with a growing number of manufacturing partners signed up with the portal.
"The portal converts your digital file to whatever format is necessary to be able to manufacture in your usual manner."
CAD/CAM Pioneers Solutions for Seating
Carl Saunders, CEO of Vorum Research Corporation, Vancouver, British Columbia, notes, "From our perspective, what we see is a pretty significant shift over to the orthotic side. [Technology for prosthetics] has been around since the late '70s and is certainly 'mature' technology, while orthotic potential really wasn't looked at until the '90s.
"In the North American market, last year was a phenomenal year for us in P&O-especially in orthotic applications-in part because people had the opportunity to see our new software."
Three years ago, Vorum began a radical housecleaning effort, in which it essentially threw out 15 years of research and restarted all of its software from scratch. "There was a significant need," Saunders says, "but we couldn't address it unless we had a completely different software architecture than everybody's used for years."
|Image courtesy of Vorum Research Corporation.|
In January 2007, Vorum reintroduced its full fleet of CAD/ CAM solutions for spinals, AFOs, KAFOs, prosthetics, and more. "All of what we had before," Saunders says, "but in a very different interface, much more about working directly on the 3-D shapes; working, seeing your orthotic device-not just your positive model but the actual device you're making. Now you can see how it's going to look before it's manufactured, and show the patient, the patient's family, and the physician ahead of time."
Vorum's new applications include pediatric AFOs, pedorthics in the form of hard insoles about to join the soft insoles and orthopedic shoes already on its menu-and disabled seating, which Saunders says has traditionally been "a very labor-intensive process," involving large hunks of plaster and hours of labor sculpting them. Typically a form of beanbag chair is used, in which the orthotist or rehab professional positions the patient appropriately; then a vacuum pump sucks the air out of the bean-bag, leaving a rigid customized mold of the patient's body.
|Images courtesy of Vorum Research Corporation.|
Instead of creating a plaster negative model from which a positive mold can be made and adjusted, Vorum's solution allows scanning the inside of the rigid beanbag form, eliminating the need for manipulating a 200-pound plaster model.
"This is brand spanking new technology," Saunders says. "We showed it for the first time in May at the rehab and orthopedic show in Leipzig, Germany. CAM limitations prevented anyone from addressing this issue before. The complex shape capture was phenomenally challenging, but it also required a much more sophisticated carving technology than has previously existed, with three- or four-axis carvers. None of that is enough for these complex seats. So we introduced a...six-axis carving machine that allows us to produce the types of molds that are needed for seats."
Jennifer Dowell, CPO, Ohio Willow Wood/OMEGA® Clinical Research, also notes the recent focus on orthotics. "Most of our development projects are orthotically based, centering around the addition of the OMEGA Scanner, which has opened the door for orthotic applications.
Introduced by Ohio Willow Wood as part of the OMEGA Tracer® system in December 2006, the OMEGA Scanner is the only hand-held scanner certified as a Class 1 laser device. "A primary reason we chose to go this route was for cranial remolding helmets, as there's no eye safety concerns with a Class 1 laser device."
The OMEGA Scanner has enabled the clinician to create cranial helmets, insoles, AFOs, and knee braces, in addition to a full range of prosthetic applications including both upper- and lower-limb applications. Dowell announced that scanning for spinal applications will be available soon-debuting in OMEGA Tracer Version 11.
The Version 11 release will also introduce direct milling abilities that will streamline the fabrication process, eliminating the carving of foam models for molding insoles. "We are already looking ahead to Version 12 including spinal applications specific for scoliosis, custom shoes, and face masks for burn patients and fractured noses. KAFOs are in the future as well."
|Photograph courtesy of Ohio Willow Wood.|
Looking at prosthetic advancements, specifically liner technology, Dowell says, "Clinicians can create custom gel liners for their patients within the software. We are able to scan directly over skin, capturing invaginations and crevices due to scar tissue, for which you can adjust by adding or thinning the gel as needed. The OMEGA Tracer user can then e-mail Ohio Willow Wood the shape file of the liner for fabrication." There's still a considerable amount of development occurring on the prosthetic side as well, she adds, with new brim and socket designs still in development.
Dowell says that the federal government is currently working on establishing recommendations regarding the maintenance of electronic medical records (EMR). "The implementation of CAD/CAM into patient care is an integral part of becoming compliant with this federal requirement. OMEGA Tracer is already working toward providing these capabilities and continues to look at ways to not only further meet this protocol but also to provide a method that improves patient care and makes it easier for clinicians to provide that care. To accomplish this, OMEGA Tracer is working with OPIE [Software] so that the two systems share information. The partnership [makes it possible] to keep everything under one roof-with everything accessible within one system."
Increased Accuracy Spurs Progress in Breast Prostheses
Susan Cassidy, MD, president of ContourMed, Little Rock, Arkansas, describes collaborative efforts with Ohio Willow Wood that resulted in a recent upgrade of its breast prosthesis software program. "This program supports the CAD/CAM capabilities for capturing data, sending, driving our cutter, the whole process. The handheld scanners have also been a huge boon. Although we have stand-alone scanners and software packages, we've also been able to work with Ohio Willow Wood in order to have our software put on the same platform as the...upgraded Tracer system, so that anybody buying that has the capability to contact us and get [our software] enabled."
The advances in accuracy have been remarkable, she notes. "Prior to the introduction of the new software and...scanner, we always had some challenges in the fitting stage because the alignment wasn't quite right [and] the fit might not be quite as accurate as you would wish." Now, Cassidy says ContourMed has far fewer changes in the fitting-form stage. "It's decreased our cycle time, improved the accuracy, and the results are archived and easily reproducible," she says.
No Technology Is Without Its Limits
|Photograph courtesy of Ohio Willow Wood.|
But there are impediments to the use of this technology, reimbursement being foremost among them. Cassidy is working with various stakeholders to persuade Medicare to reimburse using the L-8035 code for custom breast prostheses, which is routinely downcoded to L-8030, a silicone-covered non-custom prosthesis.
"With the passage of the 2007 amendment requiring health plans that provide breast cancer mastectomy benefits to provide coverage for surgical breast reconstruction under the Women's Health and Cancer Rights Act of 1968, Congress mandated that health plans pay for surgical breast reconstruction," Cassidy explains. "Unfortunately, women who are not candidates for reconstruction or do not want further surgery are not really left with any good viable options because an external breast prosthesis is the only external prosthesis for which Medicare does not pay custom, despite the existence of a reimbursable code.
"Our website ( www.contourmed.com ) touches on this issue, and we're getting a lot of hits-the need and demand is huge. At this point, reimbursement is all that's standing in the way of significantly increased demand for the newer technology," she believes.
On the CAD/CAM Horizon
The full potential of CAD/CAM is just beginning to be tapped. Researchers are currently pursuing a number of avenues to expand the applications of the technology. Joshua S. Rolock, PhD, lead investigator on CAD/CAM research projects at Northwestern University, Chicago, notes that one of the things they are beginning to pursue is cosmetic finishing of both lower- and upper-limb prostheses. "Our initial thrust is more with upper limb, where we will try to bring some low-cost solutions that might give much higher realism to the finish of the prosthesis. But at this point, it's a conceptual thing that hasn't really gotten rolling." Several other projects are in stages too early to discuss.
Joan Lockhart, vice president of sales and marketing for SensAble Technologies Inc., Woburn, Massachusetts, a provider of touch-enabled modeling solutions and haptic devices, which can both sense (receive) and send information, said that use of its FreeForm® 3D modeling system will be expanded to include the digital modeling of prostheses. FreeForm is being used to create soft- and hard-tissue implants and prostheses faster and with fewer fittings. Innovative applications include custom-created cranial and maxillofacial implants and prostheses, such as a soft-tissue orbital implant and a nasal prosthesis.
|Photograph courtesy of Ohio Willow Wood.|
Gomez is developing a prototype scanning frame upon which scoliosis patients can be positioned in supine or prone position, or lying on their side. The portable frame can be easily placed over the examining table, Gomez notes, and by placing patients in good alignment and applying some forces, not only can you train patients to reduce the deformity using gravity, but you can also scan the desirable "end shape"-providing patients with a picture to guide them in recreating this position, as part of an exercise/training program.
By positioning patients in the desirable or "corrected" position, says Gomez, "you capture not the deformity, but the ultimate correction of the deformity-the final shape that CAD will use, rather than the usual method of capturing only the deformity and using it as the basis for creating the new shape of a theoretical correction."
Gomez, who teaches nationally and internationally, has successfully used his method on more than 1,000 patients in the United States, Colombia, and Mexico over the last five years, and is currently developing an outcomes study.
Gangming Luo, PhD, of the New York University School of Medicine and Veterans Affairs New York Harbor HealthCare System (NYHHS) Rehabilitation Engineering Research Center, shared recent upgrades to the award-winning pedorthic CAD/CAM system, LastMaker and PatternMaker.
Thirty patients with foot deformities participated in clinical testing, wherein the foot was scanned to capture its 3-D geometry. "Then an insole was created to address the various deformities that can affect the bottom of a patients foot-collapsed arches, for example."
The insole is carved based on the adjustment needed, as shown by the scan, says Luo. "The bottom of the insole fits the shoe smoothly. In this way, we can fit from the bottom and take care of the arch support if needed, building in relief from heel spurs and so forth."
A database of patterns for different shapes and sizes was also created-the most common being boots and oxfords-and imported into its software. "When a person needs a specific kind of shoe, we can just get the pattern from our library and use our pattern-making system to scale up or down to adjust the shape."
The pattern is printed on paper, which is then cut out to make the leather pattern.
All patients included in the study were satisfied with the comfort and fit of the shoes and insoles created for them, Luo reports.
Sheku Kamara, manager of operations at the Milwaukee School of Engineerings Rapid Prototyping Center (RPC) described new investigations in the area of three-dimensional modeling. They are currently working on a National Institute on Disability and Rehabilitation Research (NIDRR)-funded research program for digitally creating custom orthotics for a club foot. The work is being carried out under the supervision of Robert Rizza, PhD, (Mechanical Engineering Department, Milwaukee School of Engineering) and Xue-Cheng Liu, PhD, MD, of the Medical College of Wisconsin (MCW). "At MCW, Dr. Lius Musculoskeletal Evaluation Laboratory is employed to evaluate the clubfoot deformity," Kamara says. "Children with the deformity are asked to walk over a plate containing pressure sensors in order to determine the severity of the irregularity. Dr. Rizza uses that pressure data to construct CAD models. At RPC, our objective is to use the CAD model to digitally create an orthosis without a cast or mold."
A traditional, cast-based orthotic takes one to two weeks to deliver, he continues. Using the three-dimensional modeling system, however, creating an orthosis takes only a day and a half "and is a lot less stressful to the patient," Kamara says.
The greatest challenge, he says, is working with the appropriate polypropylene material necessary for a serviceable orthosis-using a machine designed to produce its prototypes in nylon-based plastic.
Kamara is also developing a project to benefit people who use walkers but have problems holding onto them because of disabilities that affect their grip. "The idea is to have the person grab a clay model so you capture the imprint of their hand and their usual gripping pattern. By scanning that clay model, I can create a reverse of that digitally and can use that reverse to create a custom handle for the patient to grip. This should make it more comfortable for them to ambulate a little bit farther."
What else lies ahead for CAD/CAM and those who benefit from its capabilities? That may depend, in part, on how successful Alley's program is in paving the way for more visionaries to reshape CAD/CAM technology into forms beyond our imagination-and for the rest of us to readily and affordably access it.
Judith Philipps Otto is a freelance writer who has assisted with marketing and public relations for various clients in the O&P profession. She has been a newspaper writer and editor and has won national and international awards as a broadcast writer-producer.
Editor's note:The O&P EDGEdoes not endorse any products or vendors. This article does not attempt to cover every CAD/CAM system available on the market today, but rather to present readers with a representative sampling.