Written by Abby Robinson
After peeling off the protective film from one side, the patch – which is about the size of a postage stamp – is pressed onto the forearm of a young child. Hundreds of tiny microneedles located on the surface of the patch painlessly enter the upper layers of the child’s skin, where they quickly dissolve. Made of a medical polymer, the needles carry vaccine particles directly to the specialized cells used by the skin to battle invading microbes.
This is one scenario that Georgia Tech researchers envision for using the microneedle-based vaccine patch they are developing with immunology experts at Emory University. The patch, which could be available within five years, might be administered by persons without medical training, providing a simple way to rapidly immunize large populations during pandemics.
Microneedles are just one example of the medical devices under development at Georgia Tech, often in collaboration with institutions such as Emory. By harnessing its engineering, scientific and computing capabilities and its entrepreneurial tradition, as well as the Atlanta medical community, Georgia Tech is advancing the field of medical device design and bringing new devices to market.
“One of Georgia Tech’s major research strengths is its ability to bring engineering together with the biosciences to create new solutions for health care problems,” said Stephen E. Cross, executive vice president for research at Georgia Tech. “Georgia Tech has a history of bringing innovations from the laboratory through the functional prototype stage, while coordinating the other commercialization activities necessary to bring them to market.”
Beyond the health benefits, these medical devices also have an economic development benefit. Displaying more robust vital signs than most business sectors, the global medical device market could top $300 billion this year, according to industry estimates. Research institutions like Georgia Tech have played a critical role in this growth by developing technologies that are ultimately licensed to medical device firms or that form the basis for startup companies that commercialize them for clinical use.
The roster of Atlanta-based startup companies that have built new medical devices based on technology developed at Georgia Tech includes CardioMEMS, MedShape Solutions and Zenda Technologies. The Global Center for Medical Innovation (GCMI), a new medical device development center under construction in midtown Atlanta, promises to expand this roster, while assisting both established and early-stage companies. And startup assistance is available from the VentureLab unit in Georgia Tech’s Enterprise Innovation Institute and from the Georgia Research Alliance’s commercialization program.
Depending on the type and complexity of the medical device, the process of moving technology innovations from the research laboratory to the bedside can take years. Prototypes must be designed and improved upon, preliminary laboratory and animal tests must be conducted, and the safety and efficacy of many new medical devices must be tested in clinical trials. Most devices also require federal regulatory approval before they can be introduced into the marketplace.
This article examines various health care technologies developed at Georgia Tech that are in different stages of research, development and commercialization. The article includes devices designed for condition detection and diagnosis, monitoring and treatment, surgery, drug delivery, and rehabilitation and mobility assistance.
Devices Designed to Detect and Diagnose Clinical Conditions
Advancing the Detection of Neurological Conditions
Tests capable of detecting early Alzheimer’s disease are typically taken with a pen and paper and last about an hour and a half. Because of their length and expense, the tests are not used as regular screening tools.
Researchers at Georgia Tech and Emory University have developed a portable screening device called DETECT that makes quick neuropsychological assessments to identify mild cognitive impairment, which could indicate the early stages of Alzheimer’s disease. The device runs patients through a 10-minute battery of visual stimuli that requires simple responses, assessing cognitive abilities such as reaction time and memory capabilities.
Results of a 400-person clinical study conducted at Emory’s Wesley Woods Center demonstrated that the DETECT test had accuracy similar to that of the pen-and-paper test.
“We envision the DETECT test could be part of normal preventative care an individual receives from a general practitioner, like a prostate-specific antigen test or mammogram, serving as a cognitive impairment vital sign of sorts that can be tracked from year to year,” said Michelle LaPlaca, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
LaPlaca and device co-creator David Wright, an assistant professor of emergency medicine at Emory, founded a startup company called Zenda Technologies to commercialize the technology, which is currently being used in doctors’ offices in Georgia and Alabama. DETECT also has potential for use in assessing concussion and mild traumatic brain injury.
For another project, researchers are focusing on one of the pencil-and-paper tests neurologists administer to quickly screen for signs of cognitive dysfunction: the clock-drawing test. For example, an individual being assessed is asked to draw numbers on a circle so that it looks like a clock, with hands pointing to “10 minutes after 11.”
To automate and standardize the administration and evaluation of the clock-drawing task, Georgia Tech researchers have designed a software program called ClockReader that allows users to complete the test on a tablet computer with a stylus pen. The software provides spatial, temporal and geometric sketch information, along with behavior data, including time required to complete the task and pressure of the pen. Physicians can also watch a video of how an individual drew the clock.
“Our software program has the potential to reduce the amount of time required to analyze the results of the clock-drawing test, which would hopefully promote more frequent administration to measure variation over time,” said Ellen Yi-Luen Do, an associate professor with a joint appointment in the School of Architecture and School of Interactive Computing at Georgia Tech.
In collaboration with Allan Levey, director of the Alzheimer’s Disease Research Center at Emory University, more than 30 individuals with an average age of 75 tested the usability of the software. While most of the participants reported limited or no computer experience, their drawings using a stylus were almost identical to their drawings with a pencil and paper. The researchers are currently testing the software’s value to physicians.
This project is supported by the National Science Foundation, Korean Institute for the Advancement of Technology, Atlanta Clinical & Translational Science Institute, Health Systems Institute, and the Alzheimer’s Disease Research Center at Emory.
Neuropsychological exams are also sometimes given to individuals who have suffered a concussion. Because walking and thinking at the same time can be especially difficult for these individuals, scientists hope to use that multitasking challenge – measured by a simple radar system – to quickly screen individuals who may have suffered brain injuries.
By asking an individual to walk a short distance while saying the months of the year in reverse order, researchers at the Georgia Tech Research Institute (GTRI) are trying to determine if that person is impaired. This simple test, which could be performed on the sideline of a sporting event or on a battlefield, has the potential to help coaches and commanders decide whether athletes and soldiers are ready to engage in activity again.
“Research performed at the University of Oregon found that when a person with a concussion performs cognitive and motor skill tasks simultaneously, they have a different gait pattern than a healthy individual, and we are working to identify those anomalies in a person’s walk with a radar system similar to those used by police for measuring the speed of vehicles,” said GTRI research engineer Jennifer Palmer.
The researchers have successfully used this method to distinguish the gait patterns of healthy individuals wearing calibrated vision-impairment goggles – which have been shown by research to potentially simulate the visual impairment one might experience with a concussion – from the patterns collected when the individuals did not wear the goggles. GTRI research engineers Kristin Bing and Amy Sharma, principal research scientist (ret.) Eugene Greneker and research scientist Teresa Selee are also working on this project.
Simplifying the Detection of Cancer and Pneumonia
Another GTRI researcher, Charlene Bayer, is developing a portable breathalyzer to detect the presence of breast cancer. Bayer, a GTRI principal research scientist, designed and tested the device in collaboration with Brani Vidakovic, a professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University; Sheryl G.A. Gabram, a professor of surgery in the Division of Surgical Oncology at Emory University; and University of Ulm professor Boris Mizaikoff.
When an individual exhales into the device, compounds in the breath are trapped for further examination. The sensing methodology combines gas chromatography – a technique for separating complex compounds – with mass spectrometry, which identifies the chemical makeup of a substance. Specific patterns in the compounds are then found and used to confirm the presence or absence of the disease.
The research team conducted a clinical study analyzing more than 300 volatile organic compounds in breath samples of 20 healthy women over the age of 40, and 20 women recently diagnosed with stage II-IV breast cancer who had not yet received treatment. The results showed that the breath analysis was able to determine whether the sample came from a cancer patient or healthy subject 78 percent of the time.
Bayer recently completed a pilot study on individuals diagnosed with lung cancer, in collaboration with Suresh Ramalingam, an associate professor in the Department of Hematology and Medical Oncology at Emory University.
Also utilizing the exhalation of breath, a device called PneumoniaCheck could help identify the pathogens responsible for an individual’s pneumonia. After an individual coughs deeply into the device, the apparatus segregates contents from the upper and lower airways without complicated valves, buttons or active user control. The aerosol specimens captured from the lower lung can then be analyzed using commercial genomic DNA methods to determine the pathogen that should be treated.
“Identifying the pathogens that cause pneumonia can be challenging because a high-quality specimen from the lower lung is difficult to obtain. PneumoniaCheck contains a filter to collect the aerosolized pathogens and excludes oral contaminants from the sample to improve specimen quality,” said David Ku, a Regents professor in the Woodruff School of Mechanical Engineering at Georgia Tech. Ku is also the Lawrence P. Huang Chair Professor for Engineering Entrepreneurship in the Georgia Tech College of Management and professor of surgery at Emory University.
PneumoniaCheck has been approved by the U.S. Food and Drug Administration. The device was designed by Ku, Georgia Tech graduate students Tamera Scholz and Prem Midha, and Larry Anderson, who worked at the U.S. Centers for Disease Control and Prevention while this research was conducted. Results of verification testing of the device were published in the December 2010 issue of Journal of Medical Devices.
Facilitating Diagnoses of Heart Disease and Ear Infections
Levent Degertekin is designing tiny devices micromachined from silicon that may make diagnosing and treating coronary artery diseases easier.
Degertekin, the George W. Woodruff Chair in Mechanical Systems, and Paul Hasler, a professor in the School of Electrical and Computer Engineering at Georgia Tech, micromachined intravascular ultrasound imaging arrays with integrated electronics. The devices can be inserted into one-millimeter-diameter catheters to image the arteries of the heart in three dimensions at high resolution using high-frequency ultrasound waves.
“The ability to integrate electronics on the same silicon chip is key for successful implementation of cost-effective, flexible catheter-based imaging arrays to reduce the number of cables and electronic interference noise,” said Degertekin. “Current piezoelectric transducer materials cannot be manufactured with the precision to implement these arrays.”
The system boasts a more compact design and three-dimensional imaging capability for guiding cardiologists during interventions, such as those for completely blocked arteries. The technology also offers higher resolution than current intravascular ultrasound systems, which help diagnose vulnerable plaque, a leading cause of heart attacks.
Funding for this research currently is provided by the National Institutes of Health. To commercialize the technology, the researchers have formed a startup company called SIBUS Medical, which is receiving assistance from VentureLab, a unit of Georgia Tech’s Enterprise Innovation Institute that nurtures faculty startup companies.
Another device that may be commercialized in the future is the RemOtoscope – a smartphone attachment designed for at-home ear examinations. Ear infections result in more than 15 million doctor office visits each year in the United States because diagnosing them requires direct observation of the child’s eardrum and ear canal with a device called an otoscope.
Wilbur Lam, an assistant professor with a joint appointment in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University and the Department of Pediatrics at Emory University, envisions a physician remotely guiding placement of the device and diagnosing the condition via real-time video consultation with parents at home. Diagnosing ear infections at home could result in significant savings to the health care system.
The RemOtoscope attachment includes an illumination system that uses the smartphone’s flash as the light source, an optical system to provide magnification, and a software application to record data to the phone. With funding from the Atlanta Clinical & Translational Science Institute, Lam plans to solicit physician feedback, improve the device based on that feedback, and conduct a double-blind study assessing the diagnostic image quality of the device.
“Once we collect clinical data and quantify the diagnostic efficacy of the RemOtoscope as it compares to a conventional otoscope, we may be able to begin changing how ear infections are diagnosed and treated,” added Lam.
Devices Designed to Treat and Monitor Clinical Conditions
Designing Systems to Treat Ovarian Cancer and Pediatric Kidney Disease
There is no FDA-approved continuous bedside dialysis device for children. When critically ill children need kidney dialysis, doctors are forced to adapt adult-size dialysis equipment. These adapted adult devices can withdraw too much fluid from a pediatric patient, leading to dehydration, shock and loss of blood pressure.
To address this problem, which affects at least 4,000 children in the United States per year, doctors and engineers teamed up to develop a kidney replacement device designed especially for children. The prototype device is much smaller than existing dialysis equipment and works in tandem with equipment that supplements the function of the heart and lungs for severely ill patients.
“We have built a robust device that achieves automated and accurate fluid management,” said Ajit Yoganathan, a Georgia Tech Regents professor and the Wallace H. Coulter Distinguished Faculty Chair in Biomedical Engineering.
With funding from the National Institutes of Health, Yoganathan and Arvind Santhanakrishnan, a postdoctoral fellow in the Coulter Department, worked with Matthew Paden, an assistant professor of pediatric critical care at Emory and a physician at Children’s Healthcare of Atlanta, to design the device. The team is currently testing the prototype’s biological compatibility and hopes to be ready for in vivo studies later this year and clinical trials in five years.
John McDonald, a professor in Georgia Tech’s School of Biology and chief research scientist of Atlanta’s Ovarian Cancer Institute, and research scientist Ken Scarberry are designing a similar system that would treat ovarian cancer. Comparable in principle to kidney dialysis equipment, the system would circulate a buffer solution through the peritoneal cavity to pick up free-floating cancer cells that have broken off the primary tumor. The device is the basis for a startup company called Sub-Micro.
Added to fluids removed from the abdomen, magnetic nanoparticles engineered to capture cancer cells would latch onto the free-floating cancer cells, allowing both the nanoparticles and cancer cells to be removed by magnetic filters before the fluids are returned to the body. In mice injected with ovarian cancer cells, a single treatment with an early prototype of the system captured enough of the cancer cells that the treated mice lived nearly one-third longer than untreated ones.
The research, which was published in the January 2011 issue of the journal Nanomedicine, has been supported by the Georgia Research Alliance, the Ovarian Cancer Institute, the Robinson Family Foundation and the Deborah Nash Harris Endowment. Sub-Micro also has raised private funding to support its prototype development and is receiving assistance from VentureLab, a unit of Georgia Tech’s Enterprise Innovation Institute that nurtures faculty startup companies.
Utilizing Smartphones to Monitor Cancer Treatment and Parkinson’s Disease
For individuals receiving treatment for cancer, complete blood counts are vital for assessing the degree of toxicity from treatment with chemotherapy or radiation, which places patients at high risk for serious infections and requires that they remain at home to prevent acquiring infections from public places.
Instead of making weekly visits to clinics or commercial laboratories to have blood drawn, patients may one day use a cell phone attachment and software being developed by biomedical engineers to measure platelet count, neutrophil count and hemoglobin levels in real time at home. The information can be obtained from a single drop of blood obtained via finger prick.
Analogous to at-home glucose monitors that diabetics use, the device – called the Quantum CBC – uses a cell phone-integrated microscope to analyze the blood, which is loaded into a disposable cartridge. The cartridge contains a channel with a fluorescent dye that binds to platelets and white blood cells, along with quantum dots targeted to neutrophils.
“Using this system, patients could test themselves whenever and wherever they desire to determine when they are at risk for infection, when they can leave their homes and when they require a transfusion,” said Wilbur Lam, an assistant professor with a joint appointment in the Coulter Department and the Department of Pediatrics at Emory University. “This device will empower cancer patients, allowing them to take an active role in their treatment and enhance their quality of life.”
Lam is collaborating on this project with Gang Bao, the Robert A. Milton Chair in Biomedical Engineering and College of Engineering Distinguished Professor at Georgia Tech. It is supported by the Coulter Foundation.
Also using smartphone technology, researchers at the Georgia Tech Research Institute (GTRI) have developed a novel iPhone application that may enable persons with Parkinson’s disease to use the ubiquitous devices to collect data on hand and arm tremors and relay the results to medical personnel. The researchers believe the application could replace subjective tests now used to assess the severity of tremors, while potentially allowing more frequent patient monitoring without costly visits to medical facilities.
The program, known as iTrem, utilizes the iPhone’s built-in accelerometer to collect data on a patient. The application directly tracks tremor information and in the future may use simple puzzle games to record tremor data, which will then be processed and transmitted. The GTRI development team presented a paper on iTrem in January at the 2011 International Conference on Health Informatics.
“We expect iTrem to be a very useful tool for patients and their caregivers,” said Brian Parise, a research scientist who is principal investigator for the project along with Robert Delano, another GTRI research scientist. “And as a downloadable application, it also promises to be convenient and cost-effective.”
iTrem will undergo a clinical study led by Stewart Factor, a professor of neurology at Emory University.
Improving Drug Dosing Following a Heart Attack
A research team led by Georgia Tech mechanical engineering assistant professor Craig Forest is designing a device to quickly and accurately personalize a patient’s drug dosage to prevent blood clots that can cause heart attacks.
When someone experiencing heart attack symptoms arrives at an emergency room, he or she typically receives a standard dose of aspirin and/or clopidogrel to prevent further blood clotting. But that standard dose may not be the best dose for a given individual.
With Forest’s device, a small blood sample is sent through a microchip containing a network of microfabricated capillaries that mimic the branching coronary arteries around the human heart. Because the branches contain flow restrictions of different sizes, the failure of blood to flow through the branches with smaller restrictions indicates that a higher drug dose may be required.
“This bedside device should be a huge improvement compared to the way dosage is determined today, which is by observing if the standard dosage leads to gastrointestinal bleeding, which means the administered drug dose was too large, or the patient has another heart attack, which means the dose was too small,” said Forest.
Emory University Department of Emergency Medicine assistant professor Jeremy Ackerman and Georgia Tech Regents professor of mechanical engineering David Ku are working with Forest on this project, which is supported by the American Heart Association.
Improving Treatment of Chronic Wounds
When patients spend time in the hospital recovering, they may develop chronic wounds, such as pressure ulcers, stasis ulcers and diabetic ulcers. Approximately 20 percent of the hospitalized population in the United States suffers from these chronic wounds. By gathering information about the wounds over time, clinicians can identify wounds that may require different treatment.
Current methods and devices for wound measurement range from low-tech to high-tech. Simple ruler and tracing-based methods are easy to use but lack accuracy and reliability, and require contact with the wound. Devices using structured light and stereophotogrammetry methods are accurate and repeatable, but very expensive.
Stephen Sprigle, a professor in the Georgia Tech College of Architecture’s Center for Assistive Technology and Environmental Access, and Thad Starner, an associate professor in the School of Interactive Computing at Georgia Tech, developed a low-cost, high-precision wound measurement camera. They received funding from the Georgia Research Alliance, tested the device at Atlanta’s Shepherd Center rehabilitation hospital and recently licensed it to a medical technology company.
The hand-held device, which could be used by hospitals, nursing homes and home health agencies, quickly determines and captures information on wound boundaries and wound area. The device provides fast, accurate and repeatable digital documentation of wound progression, a necessary component to validate payment from insurance and government agencies.
Improving Rehabilitation for Hand Injuries and Balance Disorders
Starner also is involved in the development of Mobile Music Touch, a device originally designed to teach people to quickly learn to play a musical instrument – but which is currently being investigated for use in hand rehabilitation. The device consists of a leather athletic glove with a small plastic box on the back and vibration motors attached to each finger. Wireless impulses from a computer, MP3 player or cell phone transmit signals to the device, causing a specific finger to vibrate. The user then presses that finger onto a key on an electronic keyboard, the key lights up and the note sounds.
Mobile Music Touch was created by Georgia Tech graduate student Kevin Huang. Currently, Starner, graduate student Tanya Markow, and architecture and computing associate professor Ellen Yi-Luen Do, are working with Deborah Backus, the associate director of spinal cord injury research at Shepherd Center, to investigate the device’s potential for hand rehabilitation.
“When people are injured, they may go through intense depression,” said Markow. “Music can bring them a level of pleasure and enjoyment, and that’s important because folks are dealing with the psychological aspects of being injured. It’s soothing and relaxing – a way to raise their spirits.”
An initial study with Shepherd Center patients indicated significant improvement in both sensory response and motor skills. Researchers found it particularly surprising because people with spinal cord injuries do not typically experience further recovery more than a year after their injuries. The researchers also were surprised that patients said they were more conscious of their hands, suggesting a change in their nervous systems.
In the area of rehabilitation from balance disorders, Georgia Tech electrical and computer engineering assistant professor Pamela Bhatti is working on a system that uses inexpensive gyroscopes embedded in a visor to monitor patients during in-home rehabilitation exercises. These vestibular rehabilitation exercises can improve balance, thus reducing dizziness, disorientation and blurred vision during head movement, and ultimately the number of falls.
Typically, a physical therapist guides a patient through vestibular rehabilitation exercises and verifies proper execution, but the patient is unsupervised for in-home exercises. Bhatti’s head angular motion-monitoring system (HAMMS) uses microelectronics and motion sensors to instantaneously capture angular head rotations during exercises in a user-friendly and untethered fashion.
With a grant from the Atlanta Clinical & Translational Science Institute, Bhatti will use HAMMS as a data-logging tool to study the execution of in-home gaze stabilization exercises by patients in the Emory University Dizziness and Balance Center.
“This device provides a user-friendly technique for tracking and optimizing rehabilitation exercises with real-time performance feedback, which I believe will result in improved outcomes, improved monitoring and reduced cost,” said Bhatti.
In the area of minimally invasive cardiac surgery, researchers have developed a technology that simplifies and standardizes the technique for opening and closing the beating heart during surgery.
Apica Cardiovascular, a Georgia Tech and Emory University medical device startup, licensed the technology from the institutions. The firm recently received a $5.5 million investment to further develop the system, which will make the transapical access and closure procedure required for delivering therapeutic devices to the heart more routine for cardiac surgeons. The goal is to expand the use of surgery techniques that are less invasive and do not require stopping the heart.
With research and development support from the Coulter Foundation Translational Research Program and the Georgia Research Alliance, the company has already completed a series of pre-clinical studies to test the functionality of the device and its biocompatibility. James Greene currently serves as the CEO of the company, which has offices in Galway, Ireland, and in Atlanta.
The technology was invented by Ajit Yoganathan, Georgia Tech Regents professor and Wallace H. Coulter Distinguished Faculty Chair in Biomedical Engineering; Vinod Thourani, an associate professor of surgery and associate director of the Structural Heart Center in Emory University’s Division of Cardiothoracic Surgery; Jorge H. Jimenez, chief technology officer of the company, who received his Ph.D. from the Coulter Department; and Thomas Vassiliades, formerly an associate professor of cardiothoracic surgery at Emory University.
Through another Georgia Tech-Emory partnership, researchers have developed a hand-held device called SpectroPen to help surgeons see the edges of tumors in real time during surgery. Statistics indicate that complete removal, or resection, of most solid tumors is the single most important predictor of patient survival.
With funding from the National Institutes of Health, SpectroPen was designed by Coulter Department professor Shuming Nie and associate professor May Dongmei Wang. The researchers recently launched a startup company called SpectroPath to further develop and commercialize this technology.
The device detects tiny nanoparticles coupled to an antibody that sticks to molecules on the outsides of tumor cells. Nie and his collaborators have shown that the SpectroPen can detect tumors smaller than one millimeter in rodents. The device was described in the October 2010 issue of the journal Analytical Chemistry.
Emory University radiology professor James Provenzale and surgeons at the University of Georgia’s College of Veterinary Medicine are currently using this device during operations to remove naturally occurring tumors in dogs. University of Pennsylvania assistant professor of surgery Sunil Singhal is applying for approval to conduct clinical trials involving patients with lung cancer.
Drug and Vaccine Delivery Devices
A new vaccine-delivery patch based on hundreds of microscopic needles that dissolve into the skin could allow individuals without medical training to painlessly administer vaccines – while providing improved immunization against diseases such as influenza. These microneedle patches could simplify immunization programs by eliminating the use of hypodermic needles, and their “sharps” disposal and re-use concerns.
The National Institutes of Health recently awarded $10 million to Georgia Tech, Emory University and PATH, a Seattle-based nonprofit organization, to advance the technology. The five-year grant will be used to address key technical issues and advance the microneedle patch through a Phase I clinical trial. The grant will also be used to compare the effectiveness of traditional intramuscular injection of flu vaccine against administration of vaccine into the skin using microneedle patches.
“We believe this technology will increase the number of people being vaccinated, especially among the most susceptible populations,” said Mark Prausnitz, a Regents professor in the Georgia Tech School of Chemical & Biomolecular Engineering. “If we can make it easier for people to be vaccinated and improve the effectiveness of the vaccine, we could significantly reduce the number of deaths caused every year by influenza.”
Prausnitz is also working with Georgia Tech postdoctoral fellow Samirkumar Patel and Emory Eye Center professor Henry Edelhauser to develop a hollow microneedle that can effectively deliver drugs to the back of the eye. This device could benefit individuals with retinal diseases such as age-related macular degeneration, which can require injections on a monthly basis. Development of the device is supported by the National Institutes of Health and the Georgia Research Alliance.
“Our hollow microneedle technology is less invasive than direct injection into the eye because the microneedle apparatus is an order of magnitude smaller than currently used intravitreal needles and its length is less than one millimeter,” said Patel.
The hollow microneedle, fabricated from stainless steel, penetrates the white of the eye – called the sclera – to reach a unique location underneath it called the suprachoroidal space. Results published in the January 2011 issue of the journal Pharmaceutical Research showed for the first time that nanoparticles and microparticles can be delivered in this way to target drug delivery to the parts of the eye needing therapy in diseases like macular degeneration.
More recently, the researchers demonstrated that microneedle injections into the suprachoroidal space resulted in sustained concentrations of drugs and particles for several months, which could enable less frequent visits to the doctor for injections.
“Because we can use the microneedle to target a drug to this specific space in the eye, we believe we can minimize side effects while maximizing exposure of the drug to the tissues where it would be most effective,” added Patel.
The researchers are currently forming a startup company based on the technology, which they plan to test in clinical trials in a few years.
Enhancing Mobility, Access for Persons with Disabilities
The Tongue Drive System is a wireless and wearable device that enables people with high-level spinal cord injuries to operate a computer and maneuver an electrically-powered wheelchair simply by moving their tongues. Maysam Ghovanloo, an associate professor in Georgia Tech’s School of Electrical and Computer Engineering, and his team have been recruiting individuals with high-level spinal cord injuries to test the system at the Atlanta-based Shepherd Center and the Rehabilitation Institute of Chicago.
Trial participants receive a clinical tongue piercing and tongue stud that contains a tiny magnet embedded in the upper ball. Users wear a wireless headset outfitted with sensors that track the movement of the magnetic tracer in the mouth. Software running on an iPod interprets the tongue commands and translates the information into commands for the wheelchair or computer.
During the trial, participants repeat two test sessions during a six-week period that assess their ability to use the Tongue Drive System to operate a computer and navigate an electric wheelchair through an obstacle course.
“Based on previous studies, we expect that as users learn to use the system, they will move the computer cursor quicker and with more accuracy, and maneuver through the obstacle course faster and with fewer collisions,” said Ghovanloo.
This research is supported by the National Institutes of Health, National Science Foundation, and Christopher and Dana Reeve Foundation.
Researchers led by Stephen Sprigle, director of the Rehabilitation Engineering and Applied Research Laboratory at Georgia Tech, also are designing devices to improve wheelchair users’ experiences. To help elderly users who propel their wheelchairs with their feet, the researchers have designed a wheelchair seat based on tension support that allows users to sit low enough in the chair for their feet to touch the ground. The seat, which was licensed by The Posture Works, offers buttock support while maintaining a wheelchair’s folding capability.
For individuals with weak hands or poor hand sensation, it can be difficult to slow down or stop a manual wheelchair using friction on the hand rims attached to the wheels of the wheelchair. While earning his master’s degree in industrial design at Georgia Tech, Jonathan Jowers designed a hands-on brake to help these wheelchair users slow down more easily and quickly, while reducing burning and fatigue.
Individuals with quadriplegia, paraplegia and muscular dystrophy have used the device to perform a series of deceleration maneuvers on a sloped surface. During the tests, the users were able to quickly and easily maintain speed, slow down and stop using the braking system.
In the Coulter Department, assistant professor Charlie Kemp is designing robots to help people with limited mobility perform everyday tasks. Kemp designed a robot named EL-E that can find and deliver items that are highlighted with a simple laser pointer.
The robot autonomously moves to an item selected with a green laser pointer, picks up the item and then delivers it to a selected person or location. EL-E can grasp and deliver several types of household items, including towels, pill bottles and telephones.
“Humans naturally point at things, but we aren’t very accurate, so we use the context of the situation or verbal cues to clarify which object is important,” said Kemp, who is also an adjunct professor in Georgia Tech’s College of Computing. “Robots have some ability to retrieve specific, predefined objects, but retrieving generic everyday objects has been a challenge.”
More recently, Kemp designed a robot named Dusty to retrieve small objects dropped on the floor. Using a wheelchair joystick, users drive Dusty to a position in front of an object and press a button. Dusty autonomously moves forward and scoops the object into a tray for delivery. The user can navigate the robot back and press the lift button, which commands Dusty to lift the tray to a comfortable height for the user to grasp the object.
In collaboration with the Emory ALS Center, Kemp’s laboratory conducted a 20-person user study with individuals who have motor impairments. Participants were highly satisfied with Dusty, and found it easy to use.
When Alpharetta, Ga., company Access Product Marketing wanted to add a cane to its line of mobility devices, the company came to the Georgia Tech Research Institute (GTRI) for help. GTRI senior research scientist Brad Fain and his team designed a sturdy folding cane for the company.
The team designed the tip of the Hugo folding cane so that it could bear heavy loads and be highly resistive to slipping. The cane was successfully tested with 550 pounds of weight applied. The cane was also designed with an interchangeable handle that could be chosen by each user. The personalized handle feature came to the attention of the producers of the Fox television show, “House, M.D.” The main character, Dr. Gregory House, used a Hugo folding cane with a customized handle in more than eight episodes.
Increasing Sense of Touch and Awareness
While using a cane can improve balance, wearing a glove with a vibrating fingertip might improve sense of touch. Georgia Tech researchers designed such a device and attached it to 10 healthy adult volunteers who performed common sensory and motor skill tasks, including two-point discrimination, single-point touch, texture discrimination and grasp tests. The results showed that the volunteers performed statistically better on all of the tasks when mechanical vibration was applied.
The device uses an actuator made of a piezoelectric material to generate high-frequency vibration. The actuator is attached to the side of the fingertip so that the palm-side of the finger remains free and the individual wearing the glove can continue to manipulate objects.
“This device may one day be used to assist individuals whose jobs require high-precision manual dexterity or those with medical conditions that reduce their sense of touch,” said Jun Ueda, an assistant professor in the Woodruff School of Mechanical Engineering at Georgia Tech.
Minoru Shinohara, an associate professor in the School of Applied Physiology at Georgia Tech, and visiting scholar Yuichi Kurita worked with Ueda to design the device. Details were presented in May at the 2011 IEEE International Conference on Robotics and Automation in Shanghai.
In another project, researchers led by Bruce Walker, an associate professor of psychology and interactive computing at Georgia Tech, are helping to refine and improve an automated driving coach system designed at the Shepherd Center to aid drivers with brain injuries and other cognitive deficits.
The prototype system plugs into the car’s power outlet. The driver receives intermittent verbal reminders to check mirrors, speed, and distance from other vehicles and objects. When the driver completes a task, he or she presses a button positioned on the car’s armrest and then gets a brief verbal message of encouragement. If the system reminds a driver to complete a task and does not receive a response within three minutes, the system’s prompts increase in frequency.
Walker’s team gathered feedback from Shepherd Center patients who have used the automated driving coach to determine what speech and non-speech sounds and cues would be least intrusive and most helpful to its users. They are currently conducting evaluations of advanced versions of the system in the new driving simulator located in the Georgia Tech School of Psychology. They also consult with Centrafuse™, an Atlanta-based startup company that designs automotive software, on how to give the automated driving coach more functionality.
John Anschutz, the director of Shepherd’s Assistive Technology Center, led the initial development of the device, with the help of driver rehabilitation specialist Michele Luther-Krug, vice president of technology Mike Jones and director ofbrain injury research Ron Seel.
The development of medical devices is a logical outgrowth of many research activities at Georgia Tech. Moving these devices from the laboratory into the clinic is becoming an increasingly important part of Georgia Tech’s mission – and its collaborations with other institutions. The development and commercialization of medical devices supports Georgia Tech economic development goals and its mission of improving the human condition.
With design and prototyping support from the Global Center for Medical Innovation and commercialization support from the Georgia Research Alliance and Georgia Tech’s VentureLab, Georgia Tech will continue to advance the medical device industry.T.J. Becker, John Christensen, Quinn Eastman, Rick Robinson, Jane Sanders, David Terraso and John Toon also contributed to this article.