Why 3D design matters for medical equipment.
|The Predator 360 is a disposable diamond-coated catheter-based device from Cardiovascular Systems Inc.
With vascular disease being a major health problem for more than 17 million people, the continued discovery of new, more effective treatment methods is of tremendous importance. Whether it is for the buildup of arterial plaque occurring in the extremities (i.e. peripheral arterial disease (PAD)), or in the blood vessels surrounding the heart (i.e. coronary artery disease), these conditions threaten the health and compromise the lifestyles of its victims.
Both conditions affect a large number of Americans, but as many as 12 million suffer from PAD, and most are over age 65. As a result of an accumulation of plaque in peripheral arteries (commonly the pelvis or leg), those affected by PAD experience reduced blood flow in one or more extremity. While symptoms such as light to moderate leg pain are most pervasive amongst those with PAD, a lack of treatment can lead to severe pain, immobility, non-healing wounds, and eventually, limb amputation. Most alarmingly, the rise in the number of Americans suffering from diabetes and obesity has the number of cases of PAD growing at double-digit rates.
Cardiovascular Systems Inc. (CSI) sought to develop a treatment of vascular disease that would physically remove that calcified plaque in order to provide patients with a longer-term solution in their management of PAD. In August of 2010, the company developed just such a product; a second-generation disposable, diamond-coated, catheter-based device called the Diamondback Predator 360.
Seeking to develop a product for the treatment of vascular disease, one that would physically remove that calcified plaque in order to provide patients with a longer-term solution in their management of PAD, were Cardiovascular Systems Inc. (CSI) engineers. In August of 2010, CSI developed just such a product; a second-generation disposable, diamond-coated, catheter-based device – the Diamondback Predator 360. Utilizing SolidWorks enabled CSI engineers to make changes to the design and manufacturing processes, allowing for the quick and cost-effective development of the Predator 360.
Like CSI’s original Diamondback 360 device, the Predator system has its diamond-coated crown attached to a guide wire to sand away plaque while preserving healthy vessel tissue, or medial integrity – a critical factor in preventing reoccurrences. Utilizing the principle of centrifugal force, CSI’s device orbits the interior wall of the artery at speeds of 200,000rpm and grinds away up to 90% of the plaque creating the obstruction – a procedure known as orbital atherectomy. Compared to balloon angioplasty, there is obviously a great deal more design work necessary to ensure the safety and effectiveness of the device. Although CSI originally used 2D design techniques to conceptualize the technology, commercializing the products required a more capable 3D system. This enables the design team to visualize and analyze design concepts, materials, and manufacturing techniques.
After evaluating several 3D design systems, CSI chose SolidWorks, implementing its simulation analysis and technical communication software. These software sets allowed the company to easily model, test, and continually assess the device’s manufacturability, comprehensively simulate the device’s action without prototyping, and communicate the design to internal parties for additional input.
As the orbital atherectomy devices CSI used for its clinical trials were all steel, manufacturing disposable versions that adhered to FDA guidelines required an examination of less expensive materials. With SolidWorks, engineers were able to analyze, thoroughly, the utilized blend of high-strength plastics to validate performance prior to testing, and conduct structural and fatigue analyses to optimize the design and material selection. This helped CSI control costs while ensuring the device remained manufacturable, with the software’s specialized tools including DFMXpress and moldability analysis helping CSI cut development time by 25% and the cost of manufacturing by 20%.
In addition, this software allows the company to better automate assembly operations. CSI assembles its products in a Class 10,000 cleanroom. Therefore, for years, cleanroom operators had to keep paper assembly instructions in plastic sleeves and swab the documents regularly with alcohol. With 3DVIA Composer, a technical communications software suite from SolidWorks, the company’s engineers created easy-to-follow assembly animations that run on a computer terminal inside the cleanroom, eliminating the time-consuming sleeving and cleaning process. Additionally, this ensured assembly was uniform, eliminating errors that could ultimately mean faults in the product.
|Product demonstration created in 3DVIA Composer. Photo Courtesy of Cardiovascular Systems Inc.
These changes to the design and manufacturing processes enabled by SolidWorks have allowed CSI to create, quickly and cost-effectively, a unique, complex product with the Predator 360, and initial clinical trial results have been impressive. In a 35-patient, CONFIRM II study conducted at Utah Cardiology, results included a reduction in stenosis from 89% pre-procedure, to 31% post orbital treatment and 7% post-adjunctive therapy. Device run time averaged 71 seconds per patient, followed by low-pressure balloon angioplasty (mean 2.61 atmospheres of pressure) in 92% of patients, with no occurrences of perforation, slow flow, abrupt closure, or distal embolization across all study participants.
|An example of the manufacturing process for the Predator 360.
The reporting doctor, Dr. Gaurav Aggarwala states that, “This data validates that the Predator 360 can safely remove moderately to severely calcified plaque throughout the entire leg.” Dr. Aggarwala also discusses how, “This method of plaque removal, followed by low-pressure balloon angioplasty, provides predictable, repeatable results.”
The SolidWorks design software will also help in providing doctors with the necessary information on the product, as CSI is using 3DVIA Composer to create animations for consulting physicians to show how the product will inject, travel, and operate.
|Shown is the manufactured component of the Predator 360.
These in-depth, visual materials will give more doctors the information they need to make the best decision for their patients. In addition, since these sets of information tie directly to the SolidWorks design software, the product’s functionality and method of operation will display more effectively and comprehensively, with no room for human error. More than 46,000 orbital atherectomy procedures have been performed in leading institutions across the United States using CSI’s first generation Diamondback 360 product since its debut in 2007, but this only represents a small fraction of the number of PAD-related balloon angioplasties performed over that same period.
CSI hopes that education will spur higher rates of adoption moving forward, and the use of highly functional CAD tools like SolidWorks will be of tremendous help here. Additionally, the software allows the company to roll out, quickly, product improvements to make the procedure more effective and as quick and painless as possible for the patient. While sound medical science is at the heart of CSI and orbital atherectomy, this assistance on the design side is of tremendous importance in making the best and biggest impact possible in the bid to preserve cardiovascular health.
Cardiovascular Systems Inc.
St. Paul, MN