Picture the scene: you're in an operating theater and the surgeon, Professor Gero Strauss, is about to operate on your paranasal sinus. Five monitors are positioned in a semi-circle around the operating table. And hanging above the largest monitor - in the middle - are two infrared cameras.

Gero Strauss says the idea is similar to the way Global Positioning Systems (GPS) are used in cars.

"In a car, you have a satellite and the satellite can detect the car's position in relation to a map," says Strauss.

In an operation, the infrared cameras do the same thing by constantly updating and sending images of the operation. A small receiver is attached to the patient, who is filmed by the cameras. But instead of a map - as used in the GPS scenario - surgeons have computed axial tomography (CT or CAT scan) or magnetic resonance imagining (MRI) to help them on their way.

Saving vessels and nerves

The high resolution CT and MRT images can show a surgeon the precise, individual structures of bones, blood vessels and nerves. Any images recorded during the patient's pre-examination can now also be compared with what is filmed in real time during the operation. This means the surgeon can see exactly where they are working in the patient's body and navigate around any important blood vessels or nerves. The surgeon can even mark up a patient's body ‘map' to help them spot the things they need to avoid.

Effectively, the surgeon will mark in border regions - as defined areas. In the case of the sinus operation, one such area would be around facial nerves. To mark out the region, Strauss uses a computer mouse to position a series of small dots on the image, and all the data is hooked up using integrated software.

Early warning with Distance Control

"The camera recognizes the position of the patient and of the instrument, and presents them in relation to one another," explains Strauss.

Distance control works a lot like parking sensors in a car - but it's a lot more precise. The infrared cameras can measure a patient's position to the nearest quarter of a millimeter - that's the same as two or three strands of hair.

But, if the surgeon does veer too close to a critical region, an alarm sounds and the instrument - such as a surgical fraise in the sinus operation - shuts down automatically.

All the navigational data is on one monitor, while another monitor shows the real time images from inside the patient's body, filmed with an endoscope.

Safety in 3D

It's hoped that this navigation technology will make operations safer. The theater of the future is constantly being improved at the International Reference and Development Center for Surgical Technology (IRDC) in Leipzig. It may soon be possible to even work with 3D images.

Author: Anna-Lena Dohrmann, Gudrun Heise / za
Editor: Gregg Benzow