Spinal injuries can damage the nerve supply to the bladder, meaning that people cannot tell when their bladder is full and needs to be emptied. This can create excessively high pressure on the bladder, which affects the kidneys and can lead to damage that may be life-threatening. Measuring this pressure is needed to see how the bladder fills and empties. Currently, measurements are taken using a catheter inserted into the urethra so that the bladder can be filled with water. This is uncomfortable for the patient, and since the bladder is filled with saline at an unnaturally high speed, it’s also unreliable.

Researchers at SINTEF, a major research organization in Trondheim, Norway, have been developing tiny sensors to measure pressure in the body. Now they are focusing their efforts on measuring pressure in the bladder in conjunction with Sunnaas Hospital.

The tiny pressure sensor looks like a pinprick, and unlike a catheter, the sensor can be inserted under the skin by inserting a thin needle through the skin and into the bladder.

Advantages include that the sensor is positioned without causing the patient discomfort, no disruptive catheter, and a reduced risk of infection.

The sensor is currently being tested on three patients. Their long-term goal is to develop a method of implanting the sensor more permanently, since many patients need measurements to be taken regularly. This would involve sensors that could be implanted for several months or years.

At the moment, the sensor is connected to a thin wire, but the next step would be to make it wireless. Another long-term option could be to allow the measurements to be read by a smart phone. That way, any increase in pressure could be detected even when patients are at home, thereby avoiding resource-intensive and uncomfortable examinations in hospital.