AUGMENTED reality (AR) software has been developed by researchers at the University of Dundee to increase accuracy in administrating thoracic epidurals into the upper back.
It is the first time this technology – which blends virtual and real worlds through a visor headset – has been used for this purpose.
Upper back epidural procedures, known as thoracic epidurals, are essential for numbing of the upper torso area during chest and abdominal surgeries, and recovery processes post operation.
Traditionally a thoracic epidural is administered by anaesthetists by inserting a needle through the back onto bone of the spine, then angulating it along to locate a small area required for injection, near to ligaments, between vertebrae.
This “blind” approach can cause the patient pain as several insertions may be needed, and it comes with a high level of risk if the drug is inserted into the wrong area, which could result in spinal cord damage or life-threating conditions.
Honorary professor Graeme McLeod is a medical researcher at the University’s School of Medicine, and also a practicing consultant anaesthetist at NHS Tayside.
Working with NHS Tayside’s Medical Physics team at Ninewells Hospital and other private partners, Professor McLeod has optimised AR technology to simplify the upper back epidural procedure and improve accuracy of administration.
While wearing a VR headset, the anaesthetist can see reality and a virtual impression of inside the patient’s body created from a CT scan, shown as a 3D hologram over their back.
This means the anaesthetist can insert the needle straight onto the target area.
The technology was tested on 58 practicing anaesthetists of varying levels of seniority, based across Tayside, Aberdeen and Edinburgh, and was shown to half the number of needle insertions required – reducing from an average of four to two.
An academic paper outlining the revolutionary approach has been published in the British Journal of Anaesthesia.
Professor McLeod, who came up with the idea for the tool, said: “I was looking for a 3D solution to a 3D problem.
“Working with the medical physics department, we established a way to create a hologram of the internal bone structure, using images collected through CT scanning.
“We’ve developed something which could potentially revolutionise lower back epidural administration, and the opportunity is there to develop it further for deep tissue procedures, chronic pain, radiology and injections into joints.”
Thoracic epidurals are considered the most effective form of pain relief and are most commonly given to cancer patients before surgery.
But administration is so complex that many anaesthetists opt for a simpler procedure in which local anaesthetic is injected into the abdominal muscles, known as a fascial plane block.
However this has a lower level of effectiveness of pain relief, which is why researchers are keen to develop processes to improve administration of thoracic epidurals.
Professor McLeod added: “The upper back epidural is much more complicated to administer than the lower back epidural which is typically used during childbirth.
“That’s purely down to the shape of the vertebrae at the upper location – the bones overlap, the angles are more acute and getting the needle into the right place is more complex.
“It’s also very near to the lungs, spinal cord and blood vessels of the vertebral canal. If any of those were hit then there could be huge, life-threatening complications.
“Patients’ bodies can vary in appearance on the inside as much as they do on the outside.
“The bones of the vertebra could meet at different places for example, or the ligament might not be directly in the middle.
“That’s why a personalised CT scan of the patient is essential.”
The technology is currently undergoing further tests to integrate digital planning, improve automation and to simplify the user experience.
