‘X-ray’ specs give boost to surgeons

A virtual reality system has been developed which will guide surgeons during operations by helping them to ‘see’ inside a patient’s body before making a single incision.

Cutting into a patient is hazardous because surgeons may not know the exact position of an individual’s veins and organs. While removing a tumour or making internal repairs they could accidentally damage healthy tissue.

The virtual reality system combines live video images with pre-recorded medical scans of a patient’s body. The images appear on a liquid crystal display in a pair of goggles. The system, called Reality Augmentation for Medical Purposes (RAMP), was developed by Siemens in the US.

Frank Sauer, project manager for the technology at Siemens’ US central laboratory in New Jersey, explained that improved computing power is the key to making the new device work.

‘Previously RAMP would have only been available using super-computers. But now this in-situ visualisation can happen with two high-specification desktop PCs operating together processing the data.’

The virtual reality goggles are designed to work with computer tomography (CT) scans, MRI (magnetic resonance imaging) scans and ultrasound. Only one scanning technology can be used at a time, and will be chosen according to the patient’s needs.

Computer tomography uses a series of X-ray images at different depths to build up a 3D image of the patient’s internal organs. MRI does the same thing using the response of cells to magnetic fields.

Once scanned that image data is sent to the computer. At the same time the PCs are receiving images from the video cameras attached to the surgeon’s goggles. The computer will take these images and combine them to generate a dynamic three-dimensional picture. The two LCD screens in the goggles enable a stereoscopic view for the surgeon creating an impression of depth.

To avoid overwhelming the viewer with imagery, the computer can ‘erase’ much of the body from the picture, enabling surgeons to focus on the blood vessels that must be avoided or the tumour that needs to be removed.

If those vessels or tumours are intertwined the surgeon does not just have to rely on a top down view. As the picture is 3D surgeons can move their heads and look round body parts to gain a full view of their position.

The firm has demonstrated CT and MRI versions of its technology. An ultrasound version, which would provide live internal images, is soon to follow. The next step will be to conduct preliminary clinical trials for approval by US medical authorities later this year.

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