Moving Toward a More ElegantOrthopedic Device Development Path
Wed, 08/31/2005 - 10:05am
Emphasis on Testing & InspectionBy Luther Johnson and Steve Trout
This exclusive report examines the importance of testing and modeling as an integral part of a structured design process. It takes a look at how testing in the orthopedic device market has become an essential part of the design process and promises to continue to grow as more complex products are developed for patient needs.
By integrating testing processes at all stages of the development cycle, medical device manufacturers are able to perfect designs more quickly.
AT A GLANCE
As this spine test system demonstrates, multiple degree-of-freedom control technology, increased processor speeds, and sophisticated test algorithms afford device designers the multi-channel control and better compensation required to test complex orthopedic devices.
Structured design approach’s advantages
The “aerospace/automotive” connection
Hip, knee, and spine applications
The medical device industry has expanded rapidly over the past 20 years, driven in no small part by entrepreneurial medical professionals who have conceived innovative, next-generation orthopedic products that have helped improve patient quality of life worldwide. Talented surgeons, engineers, and scientists have served as the engine behind this rapidly growing industry, devoting enormous energy
In response to these pressures, large manufacturers have increasingly followed the example of their counterparts in the aerospace and automotive industries, choosing to augment the innovative entrepreneurial model with a more elegant and structured device development path. This “elegant development path” affords manufacturers the engineering wherewithal to conduct meaningful testing earlier and more frequently throughout the development process to better mitigate risk and integrate advanced modeling techniques to perfect designs more quickly.
Integration of TestingIn addition to the emergence of more structured device development programs, the orthopedic device industry is seeing an increasing sophistication in patient quality of life needs and subsequent growth in the complexity of the devices designed to meet them. Testing capabilities have evolved to meet the design challenges of these devices, and more and more design engineers are integrating testing throughout the development process from initial concept stages to clinical validation. This evolution of testing capabilities is best exemplified by the progression in orthopedic device testing needs from hip to knee to spine applications:
More complex knee applications require four controller-driven channels and must account for greater soft tissue influence.
Extremely complex spine applications require up to eight controller-driven channels and must account for a very high influence of soft tissue.
And this evolution of testing capabilities will certainly continue. As device complexity and impact on patient quality of life increases, the full integration of testing throughout the development of materials, components, and full devices will become the norm.
One way that test system suppliers have been able to match the increasing sophistication of orthopedic device designs is to leverage advanced test technologies and techniques pioneered originally for the aerospace and automotive industries. Multiple degree-of-freedom (DOF) control technology, increased processor speeds, and more sophisticated test algorithms afford device designers the multi-channel control and better compensation they require to test today’s most complex orthopedic devices.
By integrating testing processes at all stages of the development cycle, medical device manufacturers are able to perfect designs more quickly, resulting in reduced costs and decreased time-to-market. Design engineers also are able to develop safer, more reliable products using the data generated from their tests. In fact, the FDA has increasingly recognized the tight link between testing and clinical studies, using test data from the development process to validate results observed in clinical studies.
Rise of Virtual ModelingAs in the more structured development approaches employed in the automotive and aerospace industries, virtual modeling also is becoming increasingly commonplace in medical device development. Modeling offers several major benefits to design engineers, including acceleration of the development process, reduction in time-to-market, and improvements to the quality, effectiveness, and safety of the final product. However, modeling and analysis are capabilities that require considerable resources to achieve critical mass. Once these capabilities are in place in a larger corporation, they can be leveraged efficiently across many products.This rise in the use of modeling will result in the need for more device testing, not less. As medical devices become more sophisticated, more complex models will need to be developed. And as these models progress in complexity, they will need to be reconciled, or correlated, with data gleaned from regular and frequent physical testing. Thus, there will be a need for “discovery” testing earlier and more often, model validation test throughout, and more targeted “verification” testing undertaken at the end of the development process. Typically, numerous iterations of a model will be developed and tested to create confidence in the design and provide background data that can be submitted to validate results seen in clinical studies.
Emergence of Technological Driver
Luther Johnson, BSME, PE, is a product manager for MTS Systems Corp. and has more than 20 years of materials and component testing experience. Steve Trout is the biomaterials and biomechanics application specialist for MTS Systems Corp. with more than 25 years of materials and component testing experience. He is also an active member of the ASTM F04 Medical and Surgical Materials and Devices Committee. MTS Systems Corp., 14000 Technology Dr., Eden Prairie, MN 55344, is a global supplier of mechanical testing and simulation equipment in many product design verticals including medical devices. Johnson and Trout can be reached at 800-944-1687.
ONLINEFor additional information on the technologies discussed in this article, see Medical Design Technology online at www.mdtmag.com or MTS Systems Corp. at www.mts.com.