Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stretchable Balloon Electronics Get to the Heart of Cardiac Medicine

07.03.2011
Cardiologists may soon be able to place sensitive electronics inside their patients’ hearts with minimal invasiveness, enabling more sophisticated and efficient diagnosis and treatment of arrhythmias.

A team of materials scientists, mechanical and electrical engineers, and physicians has successfully integrated stretchable electronics technology with standard endocardial balloon catheters. Led by John A. Rogers, the Lee J. Flory-Founder Chair in Engineering at Illinois, the team will publish its work in the March 6 online edition of Nature Materials.

The team previously demonstrated a sensor-laden sheet that could laminate to the surface of the heart in 2010. Now they have expanded their technology to endocardial balloon catheters, one of the most common, least-invasive devices for cardiac procedures.

Catheters are long, flexible tubes that can be threaded through a vein or artery to reach the inside of the heart. Catheters with balloons at the end are commonly used for angioplasty, stent placement and other procedures as passive mechanical instruments. When in place, the balloon inflates and gently presses against the surrounding tissue to open blood vessels or valves.

Invasive cardiologists specializing in heart rhythm disorders use catheters with electrodes at the end for detecting and mapping arrhythmias and for ablation, or selectively killing small patches of cells that beat off-rhythm. Current invasive arrhythmia procedures involve two separate, rigid catheter devices: one that maps the heart point-by-point as a cardiologist maneuvers the tube in search of irregularities, and one with an electrode at the end that ablates spots identified as aberrant, one at a time.

The balloon device Rogers’ team developed can perform both functions over large areas of the heart simultaneously, using integrated arrays of multifunctional sensors and ablation electrodes.

“It’s all in one, so it maps and zaps,” said Rogers, a professor of materials science and engineering. “The idea here is instead of this single-point mapping and separate single-point zapping catheter, have a balloon that offers all that functionality, in a mode that can do spatial mapping in a single step. You just inflate it right into the cavity and softly push all of that electronics and functionality against the tissue.”

The researchers created a meshwork of tiny sensor nodes that could mount directly onto a conventional catheter balloon. The device holds an array of sensors to measure electrical activity of the cardiac muscle, temperature, blood flow, and pressure as the balloon presses against the tissue, along with electrodes for ablation. The entire system is designed to operate reliably as the balloon inflates and deflates.

“It demands all the features and capabilities that we’ve developed in stretchable electronics over the years in a pretty aggressive way,” Rogers says. “It also really exercises the technology in an extreme, and useful, manner – we put everything on the soft surface of a rubber balloon and blow it up without any of the devices failing.”

The Illinois team collaborated with cardiologists at the University of Arizona and Massachusetts General Hospital (MGH) to determine what types of features would be most useful for patient care.

For example, the researchers added temperature sensors and mapped temperature distribution on actual tissue as areas were ablated. From this data they developed a model to predict temperature distribution so cardiologists know how deep into the tissue they are ablating.

“Adding a feature such as temperature detection and distribution gives us greater insight as to what we are actually doing to the tissue,” said co-author Dr. Marvin J. Slepian, a practicing cardiologist and a professor of medicine at the Scarver Heart Center of the University of Arizona. “This will enhance the safety and effectiveness of ablation catheters, providing a new level of precision that we have not had to date, while simultaneously shortening the length of procedure times, which is an overall ‘win’ for patients, physicians and hospitals.”

Rogers’ team also worked closely with mc10, a company he co-founded that is commercializing the underlying technology for both medical and non-medical applications. Several researchers at mc10 are co-authors of the paper. The company has tested the devices in live animal experiments with medical collaborators at Arizona and MGH.

The biggest challenge for the researchers was ensuring full functionality of the electronics at all levels of balloon inflation. Since the center of the balloon stretches more than the ends, they had to figure out the range of strain the sensors would encounter and how to accommodate it so that sensors at the most strained points would function the same as those at areas of lower strain.

Through a collaboration with researchers at Northwestern University, led by Younggang Huang, the team solved this problem by mounting the sensors and electrodes on tiny rigid islands so they wouldn’t be affected by the balloon stretching. They also used spring-like interconnects between the sensors to handle the 100 percent distance increase between the islands when the balloon inflates.

The fabrication techniques the engineers used in developing the balloon device could be exploited for integrating many classes of advanced semiconductor devices on a variety of surgical instruments. For example, the team also demonstrated surgical gloves with sensor arrays mounted on the fingertips to show that the electronics could be applied to other biomedical platforms.

Next, Rogers would like to further increase the density of sensors on the balloon, up to thousands of tiny, multiplexed devices on the surface. This design would enable the integration of sophisticated electronic systems with the capability for even greater resolution for mapping and the ability to ablate the minimal amount of tissue. He also plans to continue exploring medical device applications for stretchable, flexible electronic arrays in other surgical tools.

“Being able to embed these kinds of advanced semiconductor devices into tissue-like formats creates all kinds of new ways to do minimally invasive procedures,” Rogers said. “I’m hopeful that this will be the first of many devices that collectively can have a major impact on the way human health care is done.”

This work was supported by the National Science Foundation and the Department of Energy. The authors will present related findings at the Heart Rhythm Society Meeting in San Francisco in May.

Liz Ahlberg | University of Illinois
Further information:
http://www.illinois.edu

More articles from Medical Engineering:

nachricht Virtual Reality in Medicine: New Opportunities for Diagnostics and Surgical Planning
07.12.2016 | Universität Basel

nachricht 3-D printed kidney phantoms aid nuclear medicine dosing calibration
06.12.2016 | Society of Nuclear Medicine

All articles from Medical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>