Physicians treating patients whose spines have been damaged by arthritis or other afflictions would like to replace damaged spinal elements with artificial implants.
Development of such spinal implants isn't as advanced as it is for knees and hips, however. To help the process, engineers at Purdue University are creating a computer model to assist researchers at orthopedic device companies.
Implants are attached to cadaver spines and a hydraulic device simulates the spine's natural movements to determine how well the implant will stand up to daily activities. Data from these experiments are fed into computers to validate a complex model Purdue is putting together.
"Creating implants for the spine presents interesting challenges, different from those encountered in implants for other parts of the body," said Eric Nauman, an assistant mechanical engineering professor.
Purdue machines simulate complex movements of the human neck and lower back to determine whether implants will perform for long periods.
"In order for implants to be approved by the Food and Drug Administration, they must be shown to last 10 million cycles, or 10 million movements, which translates into about 10 years of living," said Ben Hillberry, a mechanical engineering professor leading the Purdue effort. "Our goal is to complete 10 million cycles over a four-month period."
Current treatments fuse elements of the spine, limiting normal motion. This may provide short-term pain relief, but eliminating or reducing normal spinal movement can lead to further problems for the patient in the future, said Nauman.
"Basically, the medical community is trying to create new devices that duplicate the spine's natural motion instead of immobilizing the damaged area," he said.
Archus Orthopedics Inc., based in Redmond, Wash., is working with Purdue's engineers to develop mathematical tools to accelerate development of next generation implants.
"Application of 3-D computational models such as the one at Purdue will enable companies like Archus to reduce the cost of developing implants and increase the speed of new product realization," said Jorge Ochoa, Archus' chief technology officer.
Response time: Customers of Internet telephony services such as Vonage need to be aware of information about 911 emergency calling they receive and respond to it, a consumer advocacy group warns.
Customers who fail to acknowledge receiving the 911 information by a deadline that has been extended to Sept. 28 could find their service cut off, warns John R. Perkins, president of the National Association of State Utility Consumer Advocates.
"It is crucial that consumers respond to the notice from their provider if they wish to keep their Internet-based telephone service," he said.
The deadline is part of an order by the Federal Communications Commission that requires Internet telephony providers to offer enhanced 911 emergency calling to customers. The required notifications inform customers about any differences in 911 service between their voice over Internet protocol service and traditional telephone service.
"Beyond the need to take action to avoid being disconnected, consumers should use the notices as an opportunity to fully explore the differences between traditional home telephone service and calls made over broadband," said David Bergmann, chair of the consumer advocates' telecom committee.