Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rice University seniors automate process of lengthening children’s limbs

24.04.2012
Another day, another four turns of the screw. That’s just a part of life for people, primarily children, undergoing the long and difficult process of distraction osteogenesis, a method to correct bone deformities that leave one limb shorter than the other.

A team of Rice University undergraduates has invented a device they hope will make the process safer and easier.

In collaboration with Shriners Hospital for Children in Houston, the students came up with “LinDi,” a self-adjusting, automated linear distractor. It eliminates manual manipulation of the screw with a motorized process that makes the gradual growth of new bone a more natural process. And for the first time in such a device, they have built in a force-feedback loop that protects fragile tissues and nerves from being overstressed.

To correct deformities suffered by as many as 10 million children due to trauma, infection or congenital causes, surgeons break a bone and apply a distractor that stretches the bone as it heals and gently nudges the arm or leg to a more appropriate length.

The distractor incorporates long pins sunk right into the bone on either side of the surgical break. As the bone heals, but before it sets, the patient uses an Allen wrench to give the drive screw a quarter turn four times a day and push the pins further apart a tiny bit at a time.

That’s inconvenient, even risky if a child or parent forgets to make the adjustment, said Rice mechanical engineering student Raquel Kahn. And wearing the bulky brace is no treat, either.

Team members Kahn, Alvin Chou, Mario Gonzalez, Stephanie Herkes and Elaine Wong took LinDi on as their senior design capstone project at the behest of Gloria Gogola, an orthopedic hand and upper-extremity surgeon at Shriners who specializes in pediatrics.

“The process of limb lengthening — essentially creating a localized mini-growth spurt — works well for bones, but is very hard on the soft tissues such as nerves and blood vessels,” Gogola said. “This team has done an outstanding job of designing a creative solution. Their device not only protects the soft tissues, it will ultimately speed up the entire process.”

“The problem with the current device is that there’s a lot of room for error,” Kahn said. “You can imagine that one might forget to turn it once, or turn it the wrong way, or turn it too much. And a lot of problems can arise in the soft tissue and the nerves surrounding the bone. That’s the limiting factor of this process. But LinDi implements a motor to make the distraction process nearly continuous.”

Kahn said the motorized, battery-operated LinDi adjusts the device almost 1,000 times every day, “so the process is more gradual and continuous, similar to actual bone growth.”

Working at Rice’s Oshman Engineering Design Kitchen (OEDK), the students had access to all the materials and expertise they needed to conceptualize, build and test a prototype even while completing their coursework. “We’re teaching students the importance of prototyping as early as possible,” said Marcia O’Malley, an associate professor of mechanical engineering and materials science and the team’s faculty adviser. “Even if it’s cardboard and tape, they’re able to visualize a project early in the process.

“One of the big features of this project is the force sensor,” she said. “If the loads on the tissue are too high, the device shuts the motor off.” O’Malley said early tests with strain gauges paid off in the team’s level of confidence when the time came to build a working prototype. “The great thing about the OEDK is that everything is so accessible here. I could say, ‘Well, that team over there is working with strain gauges. Go talk to them and find out how they’re doing it,” she said.

Current patients wear distractors for as long as it takes to complete the process, typically stretching a limb for two to four months, Kahn said. Then they leave the device on for six more weeks, like a cast, while the bone sets. Each of the Rice students wore a standard distractor (minus the bone-drilling part) for 24 hours to get a feel for what patients endure. “The hardest part was we kept banging into things,” Gonzalez said.

But through interviews with Gogola’s patients, they learned how tough children are. “We were really concerned, because it looks like a pretty scary, uncomfortable process,” Herkes said. “It looks like a torture device. We asked one little boy who had it on his humerus his No. 1 complaint and he said, ‘My school uniform is red, and it doesn’t match.’”

Through Shriners, the team got the opportunity to perform short-term animal testing that “helped us work out some of the kinks we weren’t aware of in the device,” Herkes said.

“We’ve gotten some nice results,” Kahn added. “Our device is doing what we want it to do.”

Though the students are about to graduate, they expect another team to continue development of the LinDi. One goal will be to make the device less bulky, and therefore curtail wear and tear on both the distractor and the patient.

David Ruth | EurekAlert!
Further information:
http://www.rice.edu
http://news.rice.edu/2012/04/20/lindi-a-stretch-for-student-engineers/

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>