Why isn’t augmented reality ready for spinal surgery?
At this point, augmented reality is not appropriate for use in live surgery, because the image resolution is not fine enough to be better than a surgeon. Even a 3 or 4 millimetre inaccuracy in an image you’re using to make a surgical decision is not adequate for neurosurgery – that can be the difference between being inside a nerve or the spinal cord, or outside it. So at this point it’s a good training tool, and it will continue to be a good training tool.
One of the issues in the spine is keeping the patient still. If the patient’s spine moves even 3 or 4 millimetres on the operating table – and often we’re moving patients around to get into better positions, the patient’s being ventilated, even the surgery itself can move the patient marginally – then any imaging study taken before the surgery and referenced into the surgery becomes inaccurate. And that inaccuracy plays out in the images you’re receiving.
The holy grail of robotic, augmented reality, image-guided surgery is an image that is continually updated. But our imaging modalities are either MRI or CT. A CT scan shows bones very well, but it doesn’t show soft tissues. An MRI shows soft tissues very well, but it doesn’t show bones. And you can’t do the surgery in an MRI scanner, because you need huge magnets around – anything magnetic will fly around the room.
So we’re still trying to get to an imaging modality that’s small enough to be in the operating room, safe enough to be in the operating room, and able to continuously update.
