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The Story Behind: Robotic-assisted endoscopic surgery
First came the endoscope
Surgery is serious business; it's dangerous for the patient, and can be tiring for the surgeon (many surgeries routinely take hours to complete). One approach to ease the danger and the fatigue associated with surgery is the minimally invasive approach.
Endoscopy is a minimally invasive medical procedure in which a tube with a camera is inserted into the body; the endoscope transmits images to a view-screen, takes pictures, and can be used for performing biopsies and removal of foreign objects. An endoscopy is done to either check for or identify internal problems, such as with a colonoscopy, or for laparoscopic (abdominal) and thoracoscopic (chest cavity) surgeries. Laparoscopic and thoracoscopic surgeries are, like endoscopy, minimally invasive surgical procedures, using either a natural body cavity, or an incision of .5 - 1.5 cm, instead of the hand-sized hole necessary for traditional surgery.
Endoscopes are not a new idea - inventors have been refining them since the first one was developed in the early 1800s. However, although an endoscope was successfully used in a laparoscopic surgery in 1902 (on a dog), it wasn't until much later that the minimally invasive approach to surgery would be a commonplace reality. Research was done, and procedures were improved upon, but the minimally invasive (endoscopic) approach to surgery has several drawbacks without a camera. The biggest and most obvious is that the surgeon can't really see what's happening at the surgical site. Of course, the endoscope was like a telescope in the body, but the surgeon had to look through it to see what was happening. An odd position, no doubt. Another problem was that the surgeon often would be holding the endoscope steady with one hand, and operating with the other.
With the introduction of the computer chip television camera, quickly followed by its attachment to the endoscope, research into minimally invasive surgical methods began to thrive. The endoscope-with-camera alleviated the biggest problem with laparoscopy - now the surgeon could really see what was happening - and freed both of the surgeon's hands for operating. Very useful, it turns out. Up next are robots.
Early days of robotic surgery
There are three kinds of robots. An active robot is fully autonomous - it requires no input from a surgeon during surgery. A semi-active robot is somewhat autonomous, but depends on input from the surgeon. A passive robot is fully dependent on the surgeon's input - it won't do anything without being told to do it. Passive robots are the most common in surgical procedures.
Following the PUMA 560 biopsy assist mentioned above, also in 1985, Dr. Erich Mühe performed the first robotic-assisted laparoscopic cholecystectomy (gall-bladder removal). In 1991, an active robot was used to remove soft tissue from a patient, using only inputs from a computerized preoperative planning system. In 1992, researchers developed a robot to "mill out" the femur in preparation for cement-less total hip replacements. An exact fit is critical because cement-less prostheses only succeed when the patient's bone grows into the porous coating of the implant. This procedure also eliminated the danger of femoral fractures, although it was associated with increased blood loss in clinical trials.
Tele-surgery
In the United States, doctors and researchers were looking at computer technology, virtual reality technology and successful robotic-assisted surgeries, and wondering why they couldn't be combined into one system. Scott Fisher, PhD, of NASA and Joseph Rosen, MD, a plastic surgeon at Stanford University, wanted to do just that. They imagined a "telemanipulator" to be used in minimally invasive hand surgery. They went to Phil Green, PhD, a recognized inventor and pioneer in ultrasound technology, and pitched their idea. Dr. Green and his team got to work developing a telepresence system.
Later, Richard Satava, MD, a general surgeon, heard of what was being developed and encouraged Dr. Green and his team to widen their scope. He felt like there was no reason that this technology couldn't be used for almost any surgery, and Green and his team accepted the challenge. Of course, widening the scope of a project adds to the cost of a project. And, unfortunately, any research or invention endeavour needs a steady source of funding.
Enter the army
The US Army funds a great deal of medical research, and doctors in it were particularly interested in the idea of a robotic-assisted telepresence surgical system. The army further agreed with Satava - why just hand surgery? If a surgeon sitting at a hospital in Washington DC can perform surgery on a wounded soldier in a MASH unit, that would be good for the whole army. Green and his team agreed, and with funding from the US Army, they developed and patented the Green Telepresence System.
The Green Telepresence System consists of three main components. The first is a surgeon's console, ergonomically designed for the comfort of the surgeon and for accuracy in movement. The next is a vision cart, which holds a dual light source and dual 3-chip cameras. Finally is a moveable surgical cart with 2 to 3 mounted arms, for performing the surgical movements, and a camera arm. The surgeon has a magnified 3-D image in the view port, foot pedals to control the electrocautery, camera and instruments, and master control grips that direct the robotic arms. The hand-eye axis is positioned to give the illusion to the surgeon that he or she is directly operating on the patient through an open incision, and there is sensory feedback from the tools. In addition, the instruments are designed with complex cable-driven joints at the distal end, allowing the same degree of movement as the human hand during surgery. The system was successfully tested remotely on an animal, but it has never been used in a combat situation.
Also in the early 90s, the US Army was funding the research of Yulan Wang, PhD. Dr. Wang developed an robot to hold an endoscopic camera, which he named AESOP, which stands for Automated Endoscopic System for Optimal Positioning. The AESOP is designed to hold and move an endoscopic camera and light source during minimally invasive procedures; it moves in response to joystick or foot pedal commands. (It later became voice-activated.)
Soon after that, Computer Motion produced a competing telemanipulating platform, called Zeus. Zeus used the AESOP system and two table-mounted robotic arm controlled from a surgical workstation. The surgeon, who was seated, used a 2-dimensional video monitor and instrument handles to conduct the surgery. Two-dimensional surgery is very difficult. The view is distorted, and the movements of the surgeon, no matter how ergonomic his chair, are counter-intuitive. This problem was addressed, and later versions were three-dimensional.
Patient benefits
By providing proper hand-eye co-ordination, an ergonomic position and increased dexterity, da Vinci's Hands and Zeus overcame previous obstacles to minimally invasive surgery. From the patient's point of view, there are many benefits. Specifically, there is reduced trauma to the body, reduced blood loss, less post-operative pain, a lowered risk of infection, a shorter hospital stay, a faster recovery time and less scarring. This is a relatively new medical field, so of course there are still drawbacks, but the future of surgery lies in robotics, and so long as the machines keep getting better, the better it is for the patient.
Read more about the inventor: Philip S. Green (US)