Robotic Blogs

U0307654 Lian Weiwen, Mervyn

Currently in the medical field, skull surgery to remove brain tumour is a delicate and tedious operation that lasts for an average of 9 hours. It requires 6 hours to drill through the skull and 3 hours to remove the tumour. Moreover, such tumours can be extremely invasive. Thus, their removal is extremely complicated. Furthermore, there may be a need to drill through the temporal bone which is porous and not solid. This increases the complexity of the surgery. Lastly, if the surgeon damages sensitive areas (like the inner ear and facial nerves) of the patient during surgery, it may lead to permanent distortions of the facial features of the patient. Therefore, doctors in this field face a lot of difficulty in performing these operations. (Picture from http://it.asia1.com.sg/specials/spotlight20030108_004.html)

However, a robot has provided an answer for them! In a joint collaboration between the department of mechanical and production engineering of NTU and the National Neuroscience Institute (NNI), Singapore experts have designed what is believed to be the first robot that is capable of drilling through the temporal bone to remove tumours during surgery. In addition, it is also capable of drilling through the other parts of the skull to remove deep-seated brain tumours. The six-legged computer controlled robot is called Hexapod. With its advent, it is able to shorten operation time to 50 percent. Furthermore, it is also capable of higher precision drills on the skull of the patient. This has translated to a saving in time and an increase in precision.

Before the operation, high-resolution magnetic resonance imaging (MRI) scans are done on the patient to obtain information on the location of the sensitive areas of the patient. Such locations vary from patient to patient, so the path that the robot has to take to reach the tumour differs from patient to patient.

After this information is obtained, the information is loaded onto a computer to determine the best route to reach the tumour. This route has to avoid the sensitive areas of the patient and has also got to be the shortest route. Next, the robot has to be programmed to take the route that has been planned for it. This program is written on a Linux platform.

Besides these, the computer connected to the robot is capable of being preloaded with information obtained from the MRI scans to do a simulation of the actual surgery. This means that there will be greater safety in the procedure because the simulation can be run first and errors can be spotted before the actual surgery. Lastly, the surgeon places physical markers on the patient’s head to guide the robot during the surgery. Currently, trials have been successfully completed on cadavers and trials are being done on animals.

In the technology used, there is a high level of accuracy involved. Thus, there is a need to ensure that the control circuitry has to be extremely precise. The controllers have to be well-tuned for movement of the robot and the drilling process. It appears that in this application, the concepts of locomotion and obstacle avoidance have been implemented to enable the robot to avoid the sensitive areas and to move towards its goal, the tumour.

In this robot, there seems to be little autonomy. However, this is understandable because in medical applications, if the patient has to pay a high price due to a bug in the software, it would be disastrous. It would have a severe implication on the field of robotics as critics would jump at the opportunity to argue against further research in such a field. Moreover, the feedback from the sensors given to the doctors operating the robot ensures a greater amount of safety in the procedure being performed.

Clearly, this robot is a boon to mankind in the field of medical applications. It has helped us to save time and effort. In addition, it has given us greater confidence in executing intricate and delicate medical procedures. Indeed, humans deserve better!

References:
1. http://it.asia1.com.sg/specials/spotlight20030108_004.html
2. http://virtualtrials.com/news3.cfm?item=1879
3. http://www.theage.com.au/articles/2003/01/15/1042520663224.html
4. http://www.smh.com.au/articles/2003/01/15/1042520673704.html