New research led by the University of Cambridge in the UK brings hope for people with spinal cord injury to regain control over their bladder.
Writing in a recent online issue of Science Translational Medicine, Dr. Daniel Chew, of the Cambridge Centre for Brain Repair, and colleagues describe how they tested their neuroprosthetic bladder in rats.
Neuroprosthetic devices have long been known to help paralyzed individuals regain control of an arm or a leg. Now this new study shows they may one day help them gain control of organs like the bladder.
When the spinal cord is intact, nerves sense when the bladder fills up and signal this to the brain. The ability to urinate also depends on nerves sending signals to muscles that control bladder emptying.
But in a person with spinal injury, damage to the nerves means they have no sense of when their bladder is full and no ability to empty it. They have to rely on catheters to do this for them, or the urine backs up into the kidneys. Without a catheter, they would end up with kidney failure and eventually die.
Many spinal injury patients rate being able to urinate as one of the most important functions to regain.
Electrode device senses bladder fullness, triggers emptying on cue
Dr. Chew and colleagues developed an electrode device that records sensory nerve signals that indicate when the bladder is filling up, when it is full and when it contracts.
They implanted electrodes attached to the device in the bladders of rats and saw that it was able to detect when the animals' bladders were full and by how much.
Plus, they demonstrated that the device, whose electrodes are wrapped around bundles of nerves, could block and trigger bladder emptying on cue through electrical stimulation.
There is still a long way to go before such a device can be used in humans. For instance, it needs to be miniaturized and made from materials that will work in the human body.
However, the researchers foresee a handheld version that buzzes when the patient needs to use the bathroom, and when they are ready, they just press a button to start emptying their bladder.
In another study published earlier this year, scientists in the US reported using a new technique that regrows nerves across a site of injury that enabled rats with spinal cord injury to urinate normally.