February 8th 2010

"Surgeons, Computers and Robots"

         given by Dr Rudy Lapeer
                  School of Computing Sciences, UEA

The meeting was well attended for this potentially interesting and intriguing talk. Dr Lapeer introduced himself by giving an outline of his various interests and activities as a university lecturer. He then went on to describe the main features of his work with computers and their use in robotics associated with medical surgery. These areas include Computer Assisted Surgery (CAS), Surgical Navigation (SN) and Surgical Simulation.

Then a brief resume of current techniques and problems followed. Minimally invasive surgery such as keyhole surgery is common today and is not usually aided by computers and robots. The problems which arise and which may be helped by using innovative techniques could be listed as an aid to the dexterity of the surgeon using robots and manipulators; improvements to the vision of the surgeon since he is not always able to see clearly the site on which he is working. Help here might include magnification and more navigational information. Finally perception of hidden structures could be assisted. For example, what sensitive nerve is hidden beneath the structure currently being incised.

Computers also are helpful at the planning stage of surgery and can be applied to simulation and training exercises. Surgical navigation or helping the surgeon to locate areas and image guided surgery in which a virtual image of the site is superimposed on the surgeons vision were also indicated.

Robots help the surgeon to improve the accuracy of his work since a large movement of the surgeons hand can be translated into a minute movement of the tool by the robot. Robots also give the possibility of remote surgery in which the surgeon may be some considerable distance from the patient as in dealing with operations on a battle field. We were then shown a picture of a robotic operating theatre in which the patient was surrounded by mechanisms carrying out the procedure. Another slide showed the Da Vinci machine. This has more than one arm under the control of the surgeon thereby enabling him to do work which would normally require several assistants.

Micro robots in the form of a large pill which can pass through the digestive tract transmitting video pictures along the way are already in use but the view they give is very random and they are uncomfortable for the patient.

Dr. Lapeer then moved on to describe some of his research work on surgical navigation. He described how a three dimensional image from an MRI scanned patient could be produced and manipulated and then this image could be superimposed on the view through an endoscope which is seen by the surgeon. This gives the surgeon more information about the location of his surgical instruments. The question of accuracy of alignment of the images was described. The solution seems to lie in keeping the patient perfectly motionless and in using a grid system of dots on apparatus attached to the skull of the patient via a contraption fastened in the patient's mouth. The endoscope is then adjusted so that its image of these dots is coincident with similar dots superimposed on the virtual image related to the MRI scanned volume. An accuracy of alignment of less then 2mm is currently available but greater accuracy is needed for neuro-surgery for example. Similar points of identification can be attached to the surgeon's instruments so that the location of the working tip of the instrument can be calculated by the computer and fed into the screen image viewed by the surgeon. He would then know were he was working without being able to view the work site directly.

Another area of investigation is concerned with the speed of tracking of the images seen by the surgeon. If he is using augmented reality which by the use of special eyepieces he see the actual patient's hand and for example an x-ray of the hand superimposed on his view then when he moves his head the two images must track together and maintain accuracy of alignment. The usefulness of such an augmented reality view is immediately obvious.

Examples of the use of simulation for open surgery were described. Computer generated images showing an incision through skin and other tissues were seen using modified real instruments which the surgeon could manipulate for practice. Problems here included producing a virtual flesh which had similar characteristics to real flesh when giving feedback from the simulation to the surgeon. Also the robustness of the physical apparatus was put to the test by youngsters at an open day event!

Unfortunately time ran out for us to hear details of how simulations are helping midwives deal with rare problems arising during delivery, vital training for that once in a million event.

The lecture finished with a question and answer session which gave a good indication of the great interest in the topic. Our warm thanks to Dr. Lapeer for a stimulating presentation in which he gave us a glimpse of his enthusiasm for his work and possibilities for the future.

Bernard Ambrose February 2010.