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 Overdosing on Calcium
19.06.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Observing the cell's protein factories during self-assembly
15.06.2018 | Charité - Universitätsmedizin Berlin

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: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>