Rice University bioengineering students are building a device that can help people who have impaired sensation in their feet stay upright and avoid falls.
The students expect what exists currently as a tangle of wires, sensors, circuits and motors will someday be a simple powered insole that can go into any shoe to provide additional tactile sensation to improve the wearer’s motor skills.
That sensory feedback could prevent a tumble. For many elderly and patients with diabetes who might have lost some ability to feel their extremities, that can be a lifesaver.
Rice engineering students developed a sensor system that can help the elderly and those with impaired sensation in their feet avoid falls. From left: Daniel Zhang, Suzanne Wen, Yuqi Tang, Megan Kehoe and Allen Hu. Photo by Jeff Fitlow
The team of Megan Kehoe, Yuqi Tang, Suzanne Wen, Daniel Zhang and Allen Hu, senior bioengineering majors working with faculty adviser Eric Richardson, accepted the challenge posed by Dr. Mehdi Razavi, director of electrophysiology clinical research at the Texas Heart Institute. Razavi asked students working on their required capstone projects at Rice’s Oshman Engineering Design Kitchen to find a way to help his patients maintain their balance.
The students, who call themselves “All the Feels,” solved the problem by dividing the foot into four zones. Under each they placed a sensor that measures the pressure on the foot, which is used to determine how much tactile sensation the user should feel. Above each sensor they placed a vibrating motor, not unlike that found inside a cellphone, to provide additional sensation to the wearer.
They hope wearers will eventually learn to process the feedback unconsciously and adjust their strides automatically to navigate stairs or uneven terrain.
“We’ve designed the system so it can be adjusted to the patient’s needs and degree of peripheral neuropathy,” Kehoe said.
Rice University engineering student Yuqi Tang models a prototype sandal that includes a set of sensors and motors intended to help the wearer stay balanced. The prototype was built as a senior capstone design project at Rice’s Oshman Engineering Design Kitchen. Photo by Jeff Fitlow
“You’ll feel exactly where you’re applying pressure,” Wen said. “The amount of vibration is proportional to the amount of pressure: If you apply a lot, you’ll feel a lot; if you apply just a little pressure, you get just a little vibration.”
The four motor-sensor combinations under each foot operate with complete independence and were placed based on the areas of the foot that are most important for balance control. “How you respond to the vibrations shouldn’t be a conscious decision,” Kehoe added. “Your nervous system should react instantaneously.”
The sensors and motors live for the moment in the middle of a one-size-fits-all sandal for testing, but the students expect that all the elements, including a custom circuit board and the power supply, can be miniaturized. That way, a user could move them between pairs of shoes.
The team will demonstrate its invention at the George R. Brown School of Engineering Design Showcase April 13. More than 80 teams will vie for cash prizes at the annual event, which will be open to the public from 4:30 to 7 p.m. at Tudor Fieldhouse.
Rigging standard dumbbells to keep a user from getting hurt during a solo workout is pretty smart. So the Rice University students who invented the system call themselves “Smart Bells.”
Five senior mechanical engineering students developed a three-point ratcheting system that allows athletes to do all the work when lifting dumbbells, but stops them in space if, for any reason, the user releases his or her grip on the weight.
Members of the Smart Bells team are, clockwise from left: Luke Daniels, Temo Tovar, Michael Groth, Joe Ballard and David Lipsey. Photo by Jeff Fitlow
The Smart Bells team expects to demonstrate its self-spotting dumbbells at the George R. Brown School of Engineering Design Showcase April 13. More than 80 teams will vie for cash prizes at the annual event, which will be open to the public from 4:30 to 7 p.m. at Tudor Fieldhouse on the Rice campus.
The project came about at the request of the Rice Athletics Department, said Michael Groth, who built the device with fellow team members at the university’s Oshman Engineering Design Kitchen. “They wanted something that would allow athletes to exercise with heavy dumbbells and not worry about having a spotter there,” he said.
“You don’t need a whole bunch of these for a gym, just one or two,” said teammate Luke Daniels, who noted the standard dumbbells are interchangeable. “Rice athletes often have crazy schedules, with courses and meetings and labs, and when you need to go work out outside of practice, you might not have anyone with you at that time.”
“If you can’t complete an exercise, there’s a lot of potential for injury,” Groth added. “They wanted a device that could safely protect exercisers while still allowing for free range of motion, so they get the benefit of using stabilizer muscles that dumbbells give and resistance machines do not.”
Rice engineering student Joe Ballard, left, and Luke Daniels adjust the prototype of their Smart Bells system at the Oshman Engineering Design Kitchen. Photo by Jeff Fitlow
Train engineers recognize the basic idea behind Smart Bells as a dead man’s switch that stops a locomotive when a handle is released. But the students who selected the project as their required senior capstone design looked to a few more accessible inspirations as well.
“The spotting mechanism was inspired by car seat belts, because they already use a mechanism that pulls a retracting cable in when you want it to, and can also lock the cable,” team member David Lipsey said. “Seat belts have a much smaller ratchet-and-pawl mechanism.”
“And we thought about ratcheting tie-downs, which allow us to pull something in and won’t let us pull back the other way,” Temo Tovar said. “The way to implement that is with a ratchet and pawl. But we needed a way to disengage the pawl whenever a person wanted to be free to do the exercise.”
Luke Daniels checks a pulley system on the Smart Bells prototype. Photo by Jeff Fitlow
That required the simultaneous activation of solenoids on each motor with an easy-to-grip button on the dumbbell handle. When the handle and button are released, the solenoids release the spring-loaded pawl back onto the ratchet, which instantly freezes the weight. “Having the ratchet means you can still push it up, but you can’t pull it down,” Tovar said.
The students also drew inspiration from cable systems that suspend stunt actors required to fly through scenes, Groth added. “They have a three- or four-point cable system that moves them,” he said. “Having multiple cables balances out the horizontal force. We realized it was OK to just use three.”
The students plan to have two dumbbells rigged and ready for demonstration at the showcase, he said.
“A full system will require two sets of three motors, one for each hand,” said Joe Ballard, also a linebacker for the Rice football team. “We want to have buttons for each dumbbell for symmetry. You don’t want it to feel one way in one hand and feel differently in the other because that may throw you off when you use dumbbells outside of this device.”
Rice mechanical engineering lecturer Matthew Elliott is the team’s faculty adviser.
Getting a prosthetic leg will be a little more comfortable for patients with a device assembled by Rice University freshmen.
The Castaway team of students reconfigured an exercise machine to support patients who have to stand as they are fitted for prosthetics. The goal is to help them be as comfortable as possible while casts are made and prosthetics fitted.
Rice freshman Isabel Gonzalez adjusts a setting on the Castaway team’s device to make long fitting sessions more comfortable for patients being fitted for a prosthetic leg. Photo by Jeff Fitlow
The students — Michael Young, Isabel Gonzalez, Brian Ying, Regina Barcio and Chinwe Appio-Riley — chose the project during a freshman engineering class that challenges them to find practical solutions for real-world problems.
The project began with a request by the Texas Medical Center branch of the Hanger Clinic, which specializes in prosthetics and orthotics. The hope was to not only make patients more comfortable, but also make the final prosthetic a better fit.
“Right now, they use parallel bars, so the patients have to support themselves with just their hands,” Barcio said. “And bigger patients can’t really use the bars.”
The stand, built at Rice’s pioneering Oshman Engineering Design Kitchen, features a backrest and adjustable armrests to help patients balance and stabilize themselves as they stand on one leg for extended periods. “Our stand is designed for patients from 3 feet 6 inches to 6 feet 6 inches tall, and if they’re taller than that, they might have to lean over a bit,” Barcio said.
Team Castaway, from left: Michael Young, Brian Ying, Isabel Gonzalez, Regina Barcio and Chinwe Appio-Riley. Photo by Jeff Fitlow
“The key thing about being casted is being able to stand upright,” Appio-Riley said. “That way, when they make the mold for a leg, it fits perfectly. If the patient is slouching a little bit, it can mess up the mold and it won’t be comfortable.”
The stand would come in handy at both the initial casting and the final fitting, she said. “They make a plaster (cast of the limb) and use that as a mold because they’re going to make a silicon sheath to put the rest of your leg in,” Appio-Riley explained. “That’s what will hold your leg and attach it to the prosthetic. Plastering takes about 20 minutes, and taking it from plaster to plastic takes about two weeks. Then they’ll order the prosthetic to be attached.”
To test the stand, the team recruited fellow students to hold a position for as long as they could, Ying said. “The record was about two hours,” he said.
Team Castaway member Michael Young prepares to drill a part in the machine shop at the Oshman Engineering Design Kitchen. Photo by Jeff Fitlow
The students said they expect to deliver their prototype to the clinic for further refinement. The project was co-sponsored by the Rice 360˚ Institute for Global Health and the Howard Hughes Medical Institute. Renata Ramos, the team’s faculty adviser, is a lecturer in bioengineering at Rice.
The Castaway team will be among dozens from Rice competing for cash prizes at the George R. Brown School of Engineering’s annual Engineering Design Showcase at the university’s Tudor Fieldhouse at 4:30 p.m. April 13. The event is open to the public.
Rice University and Brazil’s Pontifical Catholic University of Rio Grande do Sul (PUCRS) will establish a student-exchange program focused on engineering design, thanks to a grant awarded March 13 by the 100,000 Strong in the Americas Innovation Fund.
The fund is a joint effort by the State Department, corporate and private partners to increase to 100,000 by 2020 the annual number of both U.S. students studying in Latin America and the Caribbean and foreign students from the Western Hemisphere studying in the U.S.
The Rice-PUCRS partnership was one of seven educational exchange partnerships awarded innovation funding by 100,000 Strong in the Americas this week. The new partnerships are among more than two dozen funded by 100,000 Strong since 2014 with support from ExxonMobil Corp.
Rice’s Maria Oden, professor in the practice of engineering education and director of the Oshman Engineering Design Kitchen (OEDK), and OEDK Lecturer Matthew Wettergreen will lead Rice’s efforts on the new exchange. The program will allow students from both Rice and PUCRS to collaborate on real-world engineering design challenges that are proposed by industry and community partners and to learn to work in an international engineering environment.
Located in Rio Grande do Sul, Brazil’s southernmost state, PUCRS has more than 30,000 students and is consistently ranked among Brazil’s best private universities.
The 100,000 Strong in the Americas Innovation Fund is a public-private sector collaboration among the State Department, Partners of the Americas, NAFSA: Association of International Educators, corporations, foundations, U.S. embassies and universities. The partnerships it has helped establish between 24 U.S. universities and community colleges in 16 U.S. states and 28 higher education institutions in Argentina, Brazil, Colombia, Guyana and Mexico are intended to provide more dynamic exchange and training opportunities for students in engineering, physics, geology and geophysics.
Global health program’s Africa project is 100&Change semifinalist
February 15, 2017|Jade Boyd
HOUSTON — (Feb. 15, 2017) — At current rates of progress, it will take more than 150 years before a baby born in Africa has the same chance of survival as one born in the United States, but an international team of global health experts has mapped out a plan to do it in 10 years. All it needs to get started is $100 million.
The Rice University-based team’s odds of getting the money increased to one-in-eight with today’s announcement that Rice 360° Institute for Global Health and its partners are among the semifinalists for the MacArthur Foundation’s innovative 100&Change competition. A $100 million grant will be awarded to a single proposal that promises to make measurable progress toward solving one of the world’s significant problems. The eight semifinalists announced today were selected from more than 1,900 applicants. The foundation plans to select the winner this fall.
“A million African babies die each year, and we know that 85 percent of those deaths could be prevented with relatively simple technologies that keep babies warm, help them breathe and help doctors diagnose and manage infections and other conditions,” said Rice 360° Director Rebecca Richards-Kortum, who is leading a team that includes physicians, engineers and business and entrepreneurial experts from three continents.
Dr. Queen Dube, a clinical pediatric specialist at Malawi’s largest hospital and faculty member at the University of Malawi College of Medicine, said, “We have the human workforce trained in all these interventions, but the technology is lacking. Every morning you go to work full of this knowledge, knowing what actually works, and then you come to work and you’re confronted with 50 or 60 babies. You don’t have the right technology. You cannot do that which you were trained to do, and a baby dies in front of you. It’s very frustrating.”
Rice 360° began working with Dube and other African partners 10 years ago to design robust, inexpensive machines and technologies specifically for African hospitals. The group’s efforts have attracted national and international awards and set the stage for Rice 360°’s bold 100&Change plan to develop and implement a 17-piece Newborn Essential Solutions and Technologies (NEST) package — an integrated group of life-saving neonatal technologies.
“In working alongside Rice 360° to refine, produce and launch the Pumani, we’ve now been able to bring a much-needed product to clinicians around the world,” said Robert Miros, CEO of 3rd Stone Design. “It’s a huge step for low-cost medical technologies to actually make it to market, and with this proposal, we can pave the way for a suite of neonatal technologies to scale.”
NEST collaborator Kara Palamountain, a faculty member at the Kellogg School of Management at Northwestern University, said, “The key to this project’s success does not lie with any one technology. To end preventable newborn deaths in Africa, we must provide access to comprehensive care. The NEST bundle of technologies will enable that holistic care, and there are clear efficiencies in developing and commercializing these technologies as a bundle of goods.”
NEST collaborator Joy Lawn, professor and director of the MARCH (Maternal, Adolescent, Reproductive and Child Health) Centre at the London School of Hygiene & Tropical Medicine, said, “The 17 technologies, when paired with appropriate clinical care, could prevent most newborn deaths in Africa. Our team already has more than half of those products in the late stages of development.”
The Rice 360°-led consortium enables each partner to contribute its unique expertise toward the goal. Lawn, a pediatrician with more than 25 years of clinical and research experience in Africa, will lead efforts to evaluate the impact of NEST technologies. Theresa Mkandawire, dean of engineering at the University of Malawi Polytechnic, and Oden will use existing twinned undergraduate design studios at Rice and Malawi Polytechnic to develop and refine prototypes for clinical study and evaluation. Dube and fellow pediatricians Elizabeth Molyneux and Josephine Langton will oversee clinical studies and evaluation at the University of Malawi College of Medicine. Palamountain will focus on determining user needs, obtaining feedback about prototypes and developing commercialization plans. Finally, 3rd Stone Design will lead efforts to manufacture and gain regulatory approval for NEST technologies.
Oden said the group is committed to ending preventable newborn deaths in Africa and to creating a culture of biomedical innovation there. “There are key educational and entrepreneurial components that will ensure that NEST technologies can eventually be locally sourced, produced and repaired,” she said. “More importantly, they’ll also prepare a cadre of young entrepreneurs who are ready to lead the next generation of global health care innovation in Africa.”
The Chicago-based John D. and Catherine T. MacArthur Foundation is one of the nation’s largest independent foundations. It supports creative people, effective institutions and influential networks building a more just, verdant and peaceful world.
Rice University's Maria Oden was chosen to the 2016-2017 Class of the AAAS-Lemelson Invention Ambassadors by the American Association for the Advancement of Science (AAAS) and the Lemelson Foundation.
The AAAS-Lemelson Invention Ambassadors program serves as a platform for inventors to demonstrate their role as change agents in society and as problem solvers. Since the program’s inception in 2013, there have been two classes and 14 Ambassadors selected to showcase inventors and to inspire, inform and influence thought leaders and the global community.
Oden, a professor in the practice of engineering education and director of the Oshman Engineering Design Kitchen (OEDK) at Rice, is a proven leader in engineering design education and global health technology development. Since the opening of Rice’s OEDK in 2008, student users of the 20,000 square-foot engineering design facility have grown from 250 in the first year to over 1100 in the current academic year. Courses have also increased from fewer than 10 to well over 40 classes. Oden has personally mentored close to 1000 students on at least 200 design teams. Her student teams have filed for more than 20 patents. Over 30 student-teams have won national and international awards for their designs.
Along with her faculty colleague, Rebecca Richards-Kortum, who served as an 2014-2015 AAAS-Lemelson Inaugural Ambassador, Oden co-directs the Rice 360°: Institute for Global Health, and has led the capstone design education efforts for theRice 360° minor in Global Health Technologies and for the Bioengineering program.
AAAS and the Lemelson Foundation welcomed the 2016-2017 Ambassadors at “Celebrate Invention” July 14 at 1200 New York Avenue Northwest, Washington, DC 20005. Invention Ambassadors also shared their stories as inventors, introduced their inventions and their impact in solving global problems.
About 60 students from local middle and high schools were at Rice June 6-10 for the sixth annual Texas Diversity Council Summer Youth Program. Most of the students came from lower-income households, and the program was designed to provide lessons and activities that will equip these students for a successful transition into college and completion of their degree. Included were writing workshops, SAT/ACT practice exams, presentations on financial aid and the admissions process, leadership activities, art exhibits and a tour of Rice’s Oshman Engineering Design Kitchen (pictured). Rice Public Affairs’ Multicultural Community Relations hosted the event. (Photo by Jeff Fitlow)
Rice engineering students have created a minimally invasive device to monitor the pulse and oxygen levels of a fetus undergoing endoscopic surgery in a mother’s womb, and recently carried out proof-of-concept testing at Texas Children’s Hospital. From left: student Claudia Iriondo, Dr. Magdalena Sanz Cortes and students Thomas Loughlin, Samir Saidi and Kathryn Wallace. Photo by Jeff Fitlow
Rice University students have created a prototype of a device to monitor the pulse and oxygen levels of a fetus undergoing endoscopic fetal surgery in a mother’s womb.
The WombOx team of senior engineering students worked in close collaboration with the Texas Children’s Fetal Center to create their device, which miniaturizes the components found in a pulse oximeter commonly clipped to a patient’s finger in a doctor’s office.
Pulse oximeters “see” oxygen levels in the blood by comparing light from a source to the light that reaches a detector on the other side of the finger. The instrument can calculate oxygen saturation by how much light it senses is absorbed by the tissue.
That kind of information hasn’t been available to doctors working to help fetuses suffering from congenital defects such as spina bifida, the incomplete closure of the backbone around the spinal cord.
Texas Children’s Hospital is pioneering efforts to treat such conditions through the endoscopic procedure known as fetoscopic surgery. During surgery, doctors are able to monitor the health of a fetus through ultrasound, but that only gives them a basic heartbeat. Knowing oxygen levels in the blood is critical when doctors need to act quickly to help a fetus in distress, and the WombOx device shows potential for providing such data in real time.
Rice bioengineering students work at the Oshman Engineering Design Kitchen on their prototype of a pulse oximeter intended to monitor the vital signs of fetuses during endoscopic surgery. From left: Claudia Iriondo, Kathryn Wallace, Samir Saidi and Thomas Loughlin. Photo by Jeff Fitlow
To build the prototype, the bioengineering students, Claudia Iriondo, Thomas Loughlin, Samir Saidi and Kathryn Wallace, worked closely with Dr. Magdalena Sanz Cortes, an associate professor of obstetrics and gynecology at Baylor College of Medicine and a clinician at the Texas Children’s Pavilion for Women, as well as their Rice faculty adviser, engineering lecturer Eric Richardson. It is the product of their capstone design project, required of most senior engineering students at Rice.
A few weeks after winning the top Willy Revolution Award, a $5,000 prize presented at Rice’s annual Engineering Design Showcase for innovation in design, and days before commencement, the team spent a morning in a device-testing suite at the Pavilion for Women to watch their prototype in action.
“This project was challenging because of the size of the instruments that we work with,” Sanz Cortes said. “When we started talking about the whole project, we talked about the size of a pulse oximeter. Transforming that into the size of the device they have created is very challenging.
“The other challenging part was the mechanics, how to design something that is safe enough for the baby and can be compatible with our surgeries. It’s not a trivial matter, and they did a great job,” she said.
At first glance, the device is a loop of wire on a hollow stick. But a closer look reveals that the wire is a special hybrid that expands to a predetermined shape at the correct temperature. It carries LEDs and a photodetector on miniature circuit boards that illuminate and sense the flow of blood through the tissue underneath.
The WombOx prototype built by students at Rice miniaturizes the electronics of a pulse oximeter device to enable monitoring the vital signs of a fetus during endoscopic surgery. Photo by Jeff Fitlow
The loop is packaged in a retractable sheath that fits through the small incision made in fetoscopic surgeries. The WombOx device is used like all other endoscopic tools, with a miniature camera. The idea is to insert the tube into the mother’s womb and extend the loop. Once it expands, doctors use the video feed to guide the loop around a limb and gently tighten it, putting the sensors in place to monitor the fetus throughout the surgical procedure.
“Our design, like other endoscopic tools, is intended for single use,” Iriondo explained. ‘The device is durable enough to withstand unsheathing, expansion in the womb, attachment to the fetus and resheathing during removal.”
“We took the same components found in the finger clip and basically mounted them onto flexible circuit boards we printed here,” Loughlin said. “There are two LEDs, a red and an infrared, mounted on one side, and on the other side there’s a photodetector that will detect how much light is passing through, which is related to the absorbance properties of the blood. That’s related to how oxygenated the blood is.
“We turn the signal from the photodetector into a voltage that can be read, processed and turned into a number for oxygen saturation of the blood,” he said.
At the Oshman Engineering Design Kitchen, the team tested their device on a baby doll in a ball, modeled after a similar unit in the Texas Children’s facility. The hospital’s more sophisticated version allowed them to insert a rudimentary WombOx through a port that models an incision and successfully loop it around the arm of the doll within, following their progress on a monitor.
The focus of their project was to get the electronics right, miniaturizing the components of a pulse oximeter to fit inside a tube only a few millimeters wide. What made it possible was having a loop made of nitinol, a flexible wire of nickel and titanium that can be formed into a specific shape. It collapses within the tube and returns to its intended shape when exposed to body temperature.
The team designed a sine wave-like section into the loop to give surgeons a visual reference. If the sine disappears, the loop is too tight.
The device will now go to engineers at Texas Children’s for further refinement and validation, Wallace said.
“A lot of doctors have encouraged us and said, ‘This is amazing, I’m glad you guys are doing this.’ No one is taking it up because there’s not a huge return on investment, but this will be amazing if it can actually monitor a fetus’s vital signs and intervene if something goes wrong,” she said.
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Cali, Jonah, Kamia and Rockie are the Houston Zoo’s resident California sea lions – and they absolutely love fish.
One of the Houston Zoo’s sea lions interacts with the Sea Lion Enrichment Device developed by Rice engineering students. Photo credit: Jeff Fitlow.
They’re also highly intelligent, inquisitive mammals capable of mastering and engaging in intricate behaviors, and they enjoy frequent mental and physical stimulation. This is why the zoo recruited a group of six Rice engineering students enrolled in Introduction to Engineering Design (ENGI 120) to develop a new enrichment device for the sea lions to use during breaks from training sessions, shows and exploring their habitat at the zoo.
The students – Amelia Brumwell, Matthew Chagnot, Cody Davis, Jeremy Palmer, Brady Taylor and Jasmine Zhou – began developing the Sea Lion Enrichment Device (S.L.E.D.) in fall 2015 under the supervision of Ann Saterbak, associate dean of engineering education and professor in the practice of bioengineering education, and Matthew Wettergreen, a lecturer at the Oshman Engineering Design Kitchen (OEDK). The team worked with Houston Zoo trainers to understand the needs of the sea lions and what the trainers were looking for in an enrichment device.
“Throughout the fall semester, we went through the design process, figured out what was going to work, narrowed down our ideas and built our final prototype to give to them at the end of the semester,” Palmer said.
The S.L.E.D. is constructed from PVC pipes and consists of four pieces that can be fitted together as one or two devices. Each section has a hole covered by a rotating collar, which the sea lions must use their problem-solving skills to open. When they use their noses to push these pieces around, they can line up the holes to release fish, ice or toys from the wells.
The trainers introduced the sea lions to the device with the holes exposed, so they would learn that treats and toys were inside. Eventually the trainers closed the holes, and the sea lions learned to manipulate the device to release the items.
“Our primary concern with our design, since we’re working with the zoo and live animals, is … the animals’ safety,” Chagnot said. “Right away, that knocked out a lot of potential materials.”
“The idea whenever we make enrichment is that it satisfies a specific goal, and in this instance, it is foraging and problem-solving,” said Heather Crane, a sea lion trainer at the zoo. “The students had to make sure the device would float, and we wanted it to have four arms so that each of our four sea lions could be involved at the same time if we wanted.”
On April 21 the students had their first opportunity to watch the sea lions interact with the device, something Zhou described as an “interesting experience” for the team.
Her fellow team member, Brumwell, said that all of the interesting places around Rice – including the zoo – and the many opportunities because of these surroundings factored into her decision to come to the university.
“I love going to the zoo,” she said.
Crane called it “extremely rewarding” to have this partnership with Rice University and to be able to fuse the science of engineering and the mental engagement of the sea lions.
“For me personally, (it’s about) reaching out to the students and teaching them the safety aspects of building these types of enrichment devices and what is the goal,” she said. “It’s not just about making a toy; it’s actually about encouraging natural responses from our sea lions.”
For more information on other design projects at the OEDK, visit http://oedk.rice.edu/.
Rice University engineering students have created a method to remove ureteral stents from children that causes less pain and costs less. From left, Margaret Watkins, Valerie Pinillos, John Chen, Allen Zhao and Eric Yin. Photo by Jeff Fitlow
A simple device created by Rice University engineering students may shield young children from much of the pain of having a stent removed after a urinary tract procedure.
Their invention, the Ureteral Stent Electromagnetic Removal Bead, is part of a stent inserted into the ureter, the duct that allows urine to pass from the kidney to the bladder. The stent keeps the passageway open after a pyeloplasty procedure to remove an obstruction.
Removing the stent after four weeks of healing typically involves inserting an endoscope into the urethra and bladder to locate the stent and pull it, an invasive procedure for which children are placed under anesthesia.
The students who call themselves Rice Outstenting were asked by Dr. Chester Koh at Texas Children’s Hospital to find a way to simplify this procedure, which is currently performed on more than 2,000 pediatric patients nationwide each year. They came up with the combination of a small, coated bead of highly magnetic neodymium and a powerful electromagnet. The bead can pass safely through the urethra as the magnet pulls it out of the body, followed by the stent.
The advantages are clear: There’s less pain and it costs two-thirds less than the standard procedure because it doesn’t require anesthesia and can be completed in minutes rather than hours.
“The stent is implanted after surgery in this area because if you don’t put something inside to keep the channel open, the ureter will try to close in on itself,” said team member Allen Zhao. While the procedure is now done in a minimally invasive manner with robotic surgery, “in the past it was much more invasive, when they would just open up the child completely,” he said.
The students used a highly magnetic bead and a strong electromagnet in their method to remove ureteral stents. Photo by Jeff Fitlow
Zhao and teammates John Chen, Valeria Pinillos and Margaret Watkins are mechanical engineering majors; teammate Eric Yin is a bioengineering major.
Their device won two significant awards this month: a top $5,000 prize at Rice University’s annual Engineering Design Showcase and the grand prize for student design at the annual Design of Medical Devices Conference in Minneapolis.
The students, who were advised by Rice bioengineering lecturers Eric Richardson and Matthew Elliott, took on the project at the request of Koh, a surgeon in the Division of Pediatric Urology at Texas Children’s and Baylor College of Medicine and a member of several groups that focus on pediatric devices. “A lot of devices are designed for adults, and Dr. Koh is one of the movers trying to develop more devices that are designed for children,” Yin said.
He said Koh challenged them to look at the procedure with a fresh eye. The students briefly considered designing a stent that would dissolve over time, but decided the magnetic attachment would be far simpler and less prone to complications.
The stent itself is identical to those used currently. It’s a flexible plastic tube with curls at each end that sit in the kidney and bladder and help keep it in place. In adults, a string from the bladder end is usually run outside the body through the urethra. After four weeks, a doctor pulls it free.
But in children, “most times, the string is cut off because the doctor doesn’t want anything hanging out of the child that might lead to an infection or accidental removal,” Yin said. “We’re leaving the string in but clipping it to the appropriate length, for the size of the bladder, at the surgeon’s discretion, and tying our bead to the end of it.”
Rice mechanical engineering student John Chen pulls a magnet attached to a stent from a test device. Photo by Jeff Fitlow
The second part of the system is the custom-built electromagnet with a plastic enclosure the team designed and 3-D printed at Rice’s Oshman Engineering Design Kitchen. “It has 19 layers, 125 turns of enameled copper wire,” Yin said. “Once it’s turned on, we bring it up close (to the patient) and draw the bead out through the urethra.”
“With a couple of tweaks to the magnet power, we could access the adult market as well,” Pinillos said.
The project will move forward as a Rice-Texas Children’s collaboration led by Koh. “They’ll continue to make modifications and continue the project on its medical device development pathway,” Watkins said.
“This is an important example of where academic partnerships are needed to advance pediatric medical device projects, since the pediatric medical device pipeline is currently limited,” Koh said. “I applaud the Rice team for showing its dedication and passion to the kids under our care at Texas Children’s Hospital.”
Without a hint of irony — given that carbon buckyballs were a Nobel Prize-winning discovery at Rice — Yin mentioned the material in the bead is identical to that used in the now-banned desk toy also known as Buckyballs. Those were small, powerful magnets that, if ingested in multiples, could cause severe internal injuries.
Fortunately for the Rice team’s purposes, one small magnet is enough to make a big difference.
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