Electric Device That Tells You When to Pee

Researchers develop neuroprosthetic to restore bladder control after spinal cord injury

2 min read
Electric Device That Tells You When to Pee
Photo: Daniel Chew

People who suffer severe spinal cord injuries and subsequent paralysis often lose bladder control too. But a new electronic device may restore that bodily function. British neuroscientist James Fawcett and his colleagues have developed a neuroprosthetic device that replaces damaged nerves that convey the bladder's sense of fullness. The device also blocks or triggers bladder emptying on cue through electrical stimulation. Fawcett and his team successfully demonstrated the technology in rats and published their results yesterday in Science Translational Medicine.

In a normal bladder, nerves sense when the bladder begins to fill up and electrochemically send a message to the brain. When the signals say it's time to go, the bladder contracts, the sphincter relaxes, and presto: urination. But a spinal cord injury can disrupt the signals to the brain and eliminate the fullness sensation and muscle control. A person with this kind of injury is forced to empty his bladder with a catheter.

In Fawcett's design, parts of the spinal nerves called dorsal roots are teased out into rootlets; the rootlets are placed in an implanted microchannel electrode interface. The microchannels record signals from the nerves and can determine, by the amount of activity, when the bladder is getting full. A stimulator connected to the nerves sends high-frequency stimulation to stop the bladder from emptying itself. When the user is ready to urinate, he or she can push a button that causes the device to deliver low-frequency stimulation that allows the bladder to empty. The researchers envision a handheld device that buzzes to let the user know it's time to go. (Parents: wouldn't it be great to have a buzzer like that for potty training preschoolers?)

Of course it will be a while before the device is ready for humans. In the rat experiments, the rootlets only survived for a few months after they were placed in the microchannels. That lifespan will have to be increased considerably before the device would be useful in humans, the authors said.

In a separate approach, researchers at the University of Louisville have been experimenting with epidural stimulation of the spinal cord to restore bladder control and other functions in people with spinal cord injuries. The work has been largely successful, but experiments have only been completed in a few people. 

Illustration: Evangelos Delivopoulos

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This CAD Program Can Design New Organisms

Genetic engineers have a powerful new tool to write and edit DNA code

11 min read
A photo showing machinery in a lab

Foundries such as the Edinburgh Genome Foundry assemble fragments of synthetic DNA and send them to labs for testing in cells.

Edinburgh Genome Foundry, University of Edinburgh

In the next decade, medical science may finally advance cures for some of the most complex diseases that plague humanity. Many diseases are caused by mutations in the human genome, which can either be inherited from our parents (such as in cystic fibrosis), or acquired during life, such as most types of cancer. For some of these conditions, medical researchers have identified the exact mutations that lead to disease; but in many more, they're still seeking answers. And without understanding the cause of a problem, it's pretty tough to find a cure.

We believe that a key enabling technology in this quest is a computer-aided design (CAD) program for genome editing, which our organization is launching this week at the Genome Project-write (GP-write) conference.

With this CAD program, medical researchers will be able to quickly design hundreds of different genomes with any combination of mutations and send the genetic code to a company that manufactures strings of DNA. Those fragments of synthesized DNA can then be sent to a foundry for assembly, and finally to a lab where the designed genomes can be tested in cells. Based on how the cells grow, researchers can use the CAD program to iterate with a new batch of redesigned genomes, sharing data for collaborative efforts. Enabling fast redesign of thousands of variants can only be achieved through automation; at that scale, researchers just might identify the combinations of mutations that are causing genetic diseases. This is the first critical R&D step toward finding cures.

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