Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


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


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:

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: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>