A newly-developed device which can be implanted into the spinal column to treat severe pain could also be a potential treatment for paralysis.
The ultra-thin inflatable invention, which is about the width of a human hair, can be rolled up into a tiny cylinder, inserted into a needle, and implanted into the epidural space of the spinal column – the same area where injections are administered to control pain during childbirth.
Once correctly positioned, the device – developed by engineers and clinicians at the University of Cambridge – is inflated with water or air so it unrolls like a tiny air mattress, covering a large section of the spinal cord.
When connected to a pulse generator, the ultra-thin electrodes start sending small electrical currents to the spinal cord, which disrupt pain signals.
Early tests of the device suggest that it could be an effective treatment for many forms of severe pain – including leg and back pain – which are not remedied by painkillers. It could also be adapted into a potential treatment for paralysis or Parkinson’s disease.
However, extensive tests and clinical trials will be required before the device can be used on patients.
Although other types of spinal cord stimulation devices are currently used to treat severe pain, the most effective of these devices are bulky and require invasive surgery, while current keyhole devices are far less effective at treating pain.
By combining the clinical effectiveness of the surgical devices and the ease of implantation of the keyhole devices, the device could be an effective, long-term solution to intractable pain, which affects millions worldwide.
“The way we make the device means that we can also incorporate additional components – we could add more electrodes or make it bigger in order to cover larger areas of the spine with increased accuracy,” says Dr Damiano Barone, from Cambridge’s Department of Clinical Neurosciences.
“This adaptability could make our SCS device a potential treatment for paralysis following spinal cord injury or stroke or movement disorders such as Parkinson’s disease. An effective device that doesn’t require invasive surgery could bring relief to so many people.”
Spinal cord stimulation (SCS) is an option for those who suffer from intractable back pain or other types of neuropathic pain, but despite its effectiveness, its use is limited, with just 50,000 procedures carried out worldwide each year.
“Spinal cord stimulation is a treatment of last resort, for those whose pain has become so severe that it prevents them from carrying out everyday activities,” says Dr Barone.
“However, the two main types of SCS devices both have flaws, which may be one reason their use is limited, even though millions struggle with chronic pain every day.”
“Our goal was to make something that’s the best of both worlds – a device that’s clinically effective but that doesn’t require complex and risky surgery,” says Dr Christopher Proctor, from Cambridge’s Department of Engineering.
“This could help bring this life-changing treatment option to many more people.”
The researchers used a combination of manufacturing techniques to build their device: flexible electronics used in the semiconductor industry; tiny microfluidic channels used in drug delivery; and shape-changing materials used in soft robotics.
Their finished device is just 60 microns thick – thin enough that it can be rolled up and placed in a needle for implantation. However, after implantation, the device expands out to cover a wide area of the spinal cord, thanks to the microfluidic channels.
The researchers validated their device in vitro and on a human cadaver model. They are currently working with a manufacturing partner to further develop and scale up their device and are hoping to begin tests in patients within two to three years.
“This technology has the potential to transform clinical treatment, significantly improve pain management for so many people, and reach patients who cannot be treated with existing devices,” adds Dr Rachel Atfield, commercialisation manager at Cambridge Enterprise, the University’s commercialisation company, which has patented the device.
