ASU, Mayo Clinic team work to help diabetes patients

March 17, 2011

New device holds promise of making blood glucose testing easier

People with diabetes could be helped by a new type of self-monitoring blood glucose sensor being developed by ASU engineers and clinicians at Mayo Clinic in Arizona. Ira A. Fulton Schools of Engineering Download Full Image

More than 23 million people in the United States have diabetes. The disease is the fifth leading cause of death in the United States. It contributes to a higher risk for heart disease, blindness, kidney failure, lower extremity amputations and other chronic conditions.

Many people with diabetes are tasked with the difficulty of managing their blood glucose levels. It’s recommended that they monitor their own glucose levels, but current monitoring devices typically require  patients to perform the painful task of pricking their finger to draw blood for a test sample – and many patients must do it several times each day.

The new sensor would enable people to draw tear fluid from their eyes to get a glucose-level test sample.

Glucose in tear fluid may give an indication of glucose levels in the blood as accurately as a test using a blood sample, the researchers say.

“The problem with current self-monitoring blood glucose technologies is not so much the sensor," says Jeffrey T. LaBelle, a bioengineer. "It’s the painful finger prick that makes people reluctant to perform the test. This new technology might encourage patients to check their blood sugars more often, which could lead to better control of their diabetes by a simple touch to the eye."

LaBelle, the designer of the device technology, is a research professor in the School of Biological and Health Systems Engineering, one of ASU’s Ira A. Fulton Schools of Engineering. He is leading the ASU-Mayo research team along with Mayo Clinic physicians Curtiss B. Cook, an endocrinologist, and Dharmendra (Dave) Patel, chair of Mayo’s Department of Surgical Ophthalmology. The team reported on their early work on the sensor in the Journal of Diabetes Science and Technology last year and at various regional and national conferences.

Because of its potential impact on health care, the technology has drawn interest from BioAccel, an Arizona nonprofit that works to accelerate efforts to bring biomedical technologies to the marketplace.

“A critical element to commercialization is the validation of technology through proof-of -concept testing,” says Nikki Corday, BioAccel business and development manager. “Positive results will help ensure that the data is available to help the research team clear the technical hurdles to commercialization.”

Researchers must now compile the proper data set to allow for approval of human testing of the device.

“With funding provided by BioAccel, the research team will conduct critical experiments to determine how well the new device correlates with use of the current technology that uses blood sampling,” says Ron King, BioAccel’s chief scientific and business officer.

The results should help efforts to secure downstream funding for further development work from such sources as the National Institutes of Health and the Small Business Incentive Research Program, King says.

BioAccel also will provide assistance using a network of technical and business experts, including the New Venture Group, a business consulting team affiliated with the W. P. Carey School of Business at ASU under the supervision of associate professor Daniel Brooks.

The ASU-Mayo research team began the project with funds from a seed grant from Mayo Clinic. Researchers got assistance in the laboratory from ASU students involved in research at ASU’s Biodesign Institute and the Ira A. Fulton Schools of Engineering Fulton Undergraduate Research Initiative program.

Team members assessed how current devices were working – or failing – and how others have attempted to solve monitoring problems, LaBelle says. They came up with a device that can be dabbed in the corner of the eye, absorbing a small amount of tear fluid like a wick that can then be used to measure glucose.

The major challenges are performing the test quickly, efficiently, with reproducible results, without letting the test sample evaporate and without stimulating a stress response that causes people to rub their eyes intensely, LaBelle says.

A study commissioned by the American Diabetes Association reported that in 2007 the national economic burden related to diabetes was more than $170 billion – including about $116 billion in additional health care costs and $58 billion in lost productivity from workers debilitated by the disease.



Jeffrey LaBelle, jeffrey.labelle">">

Biodesign Institute at Arizona State University

(480) 727-9061

Ron King, info">">


(602) 385-3212


Joe Kullman, joe.kullman">">

Ira A. Fulton Schools of Engineering

(480) 965-8122 direct line

(480) 773-1364 mobile

Lynn Closway, closway.lynn">">

Mayo Clinic Public Affairs

(480) 301-4337

Joe Kullman

Science writer, Ira A. Fulton Schools of Engineering


The state of solar

March 17, 2011

Arizona has more sunny days per year than any other state in the United States, and Phoenix residents enjoy more than 300 sun-filled days per year, according to the city’s official website. Given this seemingly endless supply of sunlight, why isn’t the state completely powered by solar electricity?

ASU researchers explain why Arizona has yet to see a complete solar overhaul and what projects are under way to make solar electricity more accessible to everyone. Download Full Image

Compared to the east coast, Arizonans enjoy relatively low electricity costs. This is partly because the largest nuclear power plant in the country, Palo Verde, is located here, says Stephen Goodnick, a professor of electrical engineering in the Ira A. Fulton Schools of Engineering. Goodnick also serves as deputy director of ASU LightWorks, an initiative that brings together all light-inspired research at ASU.

Since solar is more expensive than conventional electricity, Arizona residents have been slow to convert.

“People started adopting it because of the incentives and rebates,” Goodnick says. “But without that economic incentive it just depends on helping the environment, and that motivates a much smaller group.”

Solar panels are expensive to install and cost more per watt of electricity, says Venkatachalam Krishnan, a graduate student and research assistant in the School of Electrical, Computer and Energy Engineering. While a kilowatt-hour of electricity that originated from a nuclear power plant may cost 10 to 12 cents, the same amount of solar electricity could cost 25 to 30 cents per kilowatt-hour, Krishnan says.

Large-scale solar projects have been stalled because of project financing difficulties as well. For example, the Solana Generating Station is an APS solar plant that has been in the works for several years but has not been completed due to a lack of financial support.

“They finally received loan guarantees from the government, but it took that federal intervention,” Goodnick says. Once completed in 2013, the Solana Generating Station will be one of the largest solar power plants in the world, serving 70,000 APS customers.

Aside from cost, the other reason solar is not our main source of electricity is because it is difficult to store. Sunshine is plentiful during the day, but people need access to electricity at night as well. If the prevalence of solar continues to increase within the existing energy infrastructure, this problem will need to be solved.

“There’s not a good storage technology, which you would need to mitigate the fact that it’s not working at night or if it’s a cloudy day,” Goodnick says. Engineers at ASU are working to improve existing storage methods, such as batteries, which currently don’t provide adequate storage for their weight. Another possibility is using solar thermal technology to heat up a carrier liquid, such as molten salt. The liquid can store heat for eight to 10 hours, producing steam to power turbines and generate electricity, even at night. APS will use this method at the Solana Generating Station, Goodnick says.

Once the problem of storage has been addressed, solar electricity will make more economic sense for both businesses and residents of Arizona.

“The cost of solar electric has been coming down rapidly,” Goodnick says. “Based on current trends, some say by 2015 it will be at least equal to the cost of utility electricity.”

Henry Braun is another ASU research assistant and graduate student in engineering. He says residents will probably switch to solar electricity before businesses, recognizing solar as a smart long-term investment.

“If you’re paying retail price for your electricity, it becomes worth it to do solar sooner,” Braun says.

Residents who do switch to solar will need to connect to the existing electrical grid – the network that links power suppliers and consumers. Researchers at ASU’s Power Systems Engineering Research Center are working to build a smart grid that adapts to advancing technology as hundreds of thousands of people begin producing solar power locally.

ASU researchers also are working to make solar panels more powerful and effective once they are more widely used. Solar panels are made up of solar cells, or photovoltaic cells, which are made of amorphous silicon. “It’s similar stuff to what the processor in your computer is made of,” Braun says.

Photovoltaic cells convert photons – the basic unit of light energy – directly into electricity.

“The basic idea is that when a photon hits an electron, it adds energy to it and you harvest that energy,” Braun says.

Rooftop solar panels typically have a large, rectangular surface area made up of solar cells. Unfortunately, current systems operate at about 18 percent efficiency, which means just 18 percent of the sunlight hitting the solar panel is converted into electricity. With this low efficiency rate, panels must be large enough to collect as many photons from the sun as possible, and building these large panels is expensive. However, another approach is to concentrate sunlight onto smaller, more efficient solar cells. ASU is taking its expertise in materials and combining it with the University of Arizona’s expertise in optics to develop a new technique that will make such concentrating solar systems more efficient.

“If the cost of the solar cell is the limiting factor, we could make a very small solar cell and then make a giant mirror that concentrates all the light on it,” Goodnick says. “It’s the same amount of sunlight but focused on a very small piece of solar cell.”

A solar cell built for one of these concentrated systems would operate at a 35 percent to 40 percent efficiency rate. The cell structure would be more complicated, with different types of cells layered on top of one another.

“Each part of that stack is optimized for a particular part of the solar spectrum, and that’s why it’s more efficient,” Goodnick says. These new solar panels also will be equipped with a special tracking system that allows them to follow the sun as it moves across the sky, ensuring maximum sunlight absorption all day long.

ASU’s campus is already partially powered by solar electricity. The university is considered a leader in college sustainability by the Sustainable Endowments Institute, earning a grade of A- on the College Sustainability 2010 Report Card.

“We’re about to celebrate reaching 10 megawatts of solar power generated at peak power, which is the largest of any university in the country,” Goodnick says. As the ASU campus continues its solar transformation, it also serves as a testing facility for new advances in solar technology.

Written by Allie Nicodemo, Office of Knowledge Enterprise Development

Director, Knowledge Enterprise Development