Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Promise of ‘Bladder Pacemaker’ for People With Spinal Cord Injury

02.02.2005


Their research could lead to a device that would restore bladder control for the more than 200,000 Americans living with spinal cord injury or disease-related spinal cord problems

Biomedical engineers at Duke University’s Pratt School of Engineering have demonstrated for the first time that stimulating a specific nerve in the pelvis triggers the process that causes urine to begin flowing out from the bladder, refuting conventional thinking that "bladder emptying" requires signals from the brain. Their research, carried out with animals, could lead to a "bladder pacemaker" to restore bladder control for the more than 200,000 Americans living with spinal cord injury (SCI) or disease-related spinal cord problems.
Neural engineer Warren Grill and biomedical engineering doctoral candidate Joseph Boggs found that applying small electrical currents to the pudendal nerve triggered coordinated contraction of the bladder and relaxation of the urethral sphincter, which controls the bladder’s outlet. The electrical stimulation emptied 65 percent of the bladder’s volume.


In contrast, the bladder overfills without such intervention, triggering spastic contractions that empty only about 32 percent of the volume. The urethral sphincter frequently closes, blocking the flow of urine and forcing the urine back up toward the kidneys. This backup causes the chronic urinary tract infections and kidney problems that typically plague people with SCI.

What’s surprising and encouraging about the findings, said the researchers, is that electrically stimulating the pudendal nerve caused the urethral sphincter to function normally and to efficiently empty the bladder.

Boggs, Grill and biomedical engineers Brian Wenzel and Kenneth Gustafson at Case Western Reserve University in Ohio published the findings in the Journal of Neurophysiology. The paper is now available online and will be published later in 2005. The research was sponsored by the National Institutes of Health and the Whitaker Graduate Student Fellowship program.

The researchers used cats in their studies because cats, like humans, empty their bladders through coordinated bladder and urethral sphincter activity. NIH animal care and experimental procedures were followed and approved by the Institutional Animal Care and Use Committee of Case Western Reserve University, where the studies took place.

Until now, most bladder control research has focused on treating incontinence, a major cause of health problems such as urinary tract and kidney infections, and of skin degradation. Other research teams have reported that electrical pulses with low frequencies, about 2 to 20 cycles per second, help control incontinence by calming involuntary bladder contractions, while higher-frequency pulses do not help.

The new research demonstrates that the higher-frequency pulses fail to control incontinence because they trigger bladder contractions. The team found that frequencies in the range of 20 to 40 cycles per second work best for bladder emptying. "It was a surprise that no one had figured this out yet. But now that we understand the whole picture, we can pursue an engineered solution to help people restore bladder control," Boggs said.

"With this new understanding of the function of the pudendal nerve and the beneficial application of both high- and low-frequency pulses in controlling bladder emptying and incontinence, it should be possible for us to create a ‘bladder pacemaker’ analogous to a heart pacemaker," said Grill, who previously (in 2004) published preliminary human research that supports his optimism in extrapolating from the new studies with cats. Those earlier studies showed that a similar reflex in bladder contraction exists in people with SCI.

In January 2005, the National Institutes of Health awarded Grill a 5-year, $1.8 million grant to develop a system to sense involuntary bladder contractions and trigger a calming low-frequency electrical signal. The project also seeks to enable patients to generate a high-frequency signal on demand so they can empty their bladders at will.

"More control over bladder function could significantly improve quality of life, such as by allowing people the simple freedom of going to the movies without worrying about an accident," Boggs said. "Our objective is to complete clinical testing and be able to put bladder control implants in humans by the year 2010," said Grill, who plans to carry out human experiments at Duke to follow up the research with cats.

Today, people with SCI typically manage their bladders with catheters or an implanted device that empties the bladder by stimulating sacral nerves at the base of the spine. However, implanting this "Vocare device" requires doctors to cut sensory nerves and insert electrodes into the spine. Many patients are reluctant to do this because of concerns about losing bowel control or sexual function such as erection in men and lubrication in women. "Our goal is to create a system that performs as well as existing technology, but that is less invasive to install and preserves as much of the person’s remaining function as possible," Grill said.

He envisions a simple system with an electrode on the pudendal nerve attached to an electrical signal stimulator placed in the abdomen. The bladder pacemaker operation would be optimized by a doctor and then run by the patient using a wireless control device.

Grill is a founding partner in NDI Medical Company, which has exclusive license to the selective stimulation patent relevant to this research. NDI Medical is also the U.S. distributor of the Vocare device.

Deborah Hill | EurekAlert!
Further information:
http://www.duke.edu

More articles from Health and Medicine:

nachricht Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>