Injectable pressure sensor detects full bladders for people
suffering neurological disease
4 April 2014
A small pressure sensor developed by SINTEF in Norway can help
people suffering from a neurological disease that affects control of
the bladder and can lead to a life threatening situation.
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 then creates an excessively high pressure on the
bladder, which affects the kidneys and can lead to damage that may
More than 220,000 people in Norway suffer from a neurological
disease that means that they have difficulties with urinating and
incontinence, and have problems controlling their bladders. About
3,000 of these are particularly badly affected.
Measuring pressure with a catheter
"Measuring pressure in the bladder is essential in order to see
whether an operation is necessary, or whether the condition can be
treated with medication. The measurements reveal how the bladder
fills and empties", explains Dr Thomas Glott of Sunnaas Hospital.
Currently, measurements are taken using a catheter which is
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, the method is
For many years, researchers at SINTEF have been working on
developing tiny sensors for measuring pressure in the body. When the
chance to work closely with Sunnaas Hospital came up, they decided
to focus on measuring pressure in the bladder.
The sensor is small enough to be inserted through the skin and
into the bladder using a thin needle. It is positioned without
causing discomfort to the patient, who can then move about normally
without the disruptive catheter, and thus reducing the risk of
The sensor is now being tested on three patients. One long-term
plan is to test the system on 20–30 patients.
"Working with Sunnaas has given us a great chance to try out our
technology on patients. It has also provided a useful insight into
other medical applications. Our long-term aim is to develop a method
of implanting the sensor more permanently, since many patients need
measurements to be taken regularly", says Ingelin Clausen of SINTEF.
"These would be sensors that could be implanted for several months
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.