Emerald Group Publishing Limited
Copyright © 2008, Emerald Group Publishing Limited
Master and commander
Article Type: Editorial From: Industrial Robot: An International Journal, Volume 35, Issue 4
In this issue, we are revisiting medical robotics, but you do not need to be working in this area to find it of interest. What makes medical robotics so challenging and deserving of our attention is that the robots need to have very different characteristics to their industrial cousins.
For robots working in industry, speed of operation and rigidity are prime design goals, whereas in medical applications these are the very characteristics that you probably want to avoid.
If your doctor has signed you up for a prostatectomy, then the very last thing you want to see is a robot brandishing a scalpel at 3 m/s.
Medical robots need to be precise and capable of very fine movements, but they do not need to work at high speed or move to precise locations in world coordinates.
Robots are now being used as a matter of routine for operations in cardiology, neurology, orthopaedics and prostatectomy.
For neurology and orthopaedics, 3D pre-operative scans of the patient are often made and the robot is first aligned and registered to the patient and then the robot proceeds with a program of moves that have normally been planned in advance and which the surgeon just oversees with a finger on the STOP button. These operations are not too dissimilar to industrial applications.
For cardiology and prostatectomy however things are very different. For one thing the patient is constantly moving and changing shape as they breath in and out. Also, there is no pre-planned program – instead the surgeon controls the robot in teleoperator mode, while working on a master that can be in a different room, or even in a different country to the slave arm that holds the endoscopic cameras and 10 mm diameter 7 DOF operating instruments.
The surgeon’s movements can be scaled down by the system software to give the surgeon a clear view and delicate control while working with arteries that may be only a millimeter in diameter.
This is very fancy (and expensive) equipment, but what can the world of industrial robotics gain from medical robots?
One lesson is that it shows that robots can be commercially viable in areas that are a million miles from mass production, and for companies struggling to make a profit from sales of robots that cost less than a 1/50th of their medical counterparts, this may come as good news. Another major feature is that teleoperation is a primary means of control and for me this is one of the most exciting areas of development, and the one that still has the greatest need for further improvement. Haptics (sense of touch) is one important addition that even the medical robots have yet to fully develop, but even ignoring this we still have a long way to go in the development of Master teleoperation.
A large percentage of industrial robots are still programmed using pushbuttons and joysticks that allow the operator to move the robot one joint at a time, or move in one axis in world or tool coordinates. This makes programming a time consuming task which in turn prohibits the use of robots in one-off applications. Imagine the new areas that robots could be used in if the robot could be taught a complex task in a matter of minutes.