Traditionally, surgeries were accomplished by cutting the skin and tissues of the patient in order to expose the structures and organs for operation. This required making sizable incisions on the patient’s body, which in turn led to consequences such as longer recovery times and large post-operative scars. Since the efforts to advance robotics in medicine started in the 1960’s, several prototypes have been created – none of them, however, has been able to successfully address the needs of complex surgery in a considerable scale. Since the beginning of the century, Intuitive Surgical’s da Vinci® Surgical System has proved itself to be a solution to the problems associated with traditional, open surgery by providing a sophisticated robotic interface between surgeon and patient. The benefits of a robot-assisted surgery include smaller incisions, reduced bleeding, faster recovery periods, and improved post-operative cosmetics.
Introduction
Nearly five centuries ago, Leonardo da Vinci designed the first robot in human form to prove that the human body’s mechanism could be emulated by machines [1]. Since then, this idea has evolved and spread to different areas of application. In the medical field, engineers have devised a robot that not only assists physicians during complex surgeries, but offers them several advantages over conventional surgical methods in use today.
The da Vinci Robot (Fig. 1), built and designed by Intuitive Surgical in Sunnyvale, California, is a robot that has been revolutionizing medicine by helping surgeons treat a multitude of conditions, including, but not limited to, bladder cancer, coronary artery disease, prostate cancer, and throat cancer [2]. By using a medical camera and precise robotic arms, the da Vinci robot creates a reliable and effective interface for the surgery, simplifying the work for the doctor and speeding up the recovery of the patient.
The History of Medical Robots
The origins of medical robots date back to the 1960’s, when the U.S military researched a method of decreasing the number of specialized surgeons on the battlefield. These efforts led to the creation of “telepresence surgery”, a platform in which a master surgeon controls a slave machine from a remote location [3]. With the collaboration of the United States Department of Defense, the National Aeronautics and Space Administration (NASA), and the Stanford Research Institute, the technology for the master-slave system was developed.
Medical robots have made an appearance on the surgical market during the past two decades, but its beginnings were relatively modest. In 1985, a surgical robot was used for drilling and performing biopsies during a brain surgery [3]. In 1989, an automaton named PROBOT was used to assist in a urological surgery and, even though it was proven to be safe and clinically effective in five patients, it was never mass produced [3]. Finally, in 1994, the Food and Drug Administration (FDA) approved the first surgical robot to be made available commercially. Known as the AESOP (Automated Endoscopic System for Optimal Positioning), it was utilized by urologists and had a robotic arm with seven degrees of freedom. This arm was used to hold and manipulate the camera, eliminating the need for a surgical assistant and allowing the surgeon to have direct control over his field of vision [3].
These advances in robotics and medicine eventually led to the creation of the da Vinci robotic system, which was approved by the Food and Drug Administration into the surgical market in 2000 [3].
A Breakdown of the da Vinci Robot
The da Vinci robot system consists of three primary components: a surgeon console, an InSite® Vision System that processes the image through the medical camera, and a medication cart that supports the robotic arms and operation tools (Fig. 2) [4]. These three components work together to give the surgeon complete control of the surgery [5].
Surgeon Console
The surgeon console is like the brain of the da Vinci Robot. It provides a workstation for the surgeon to control the robotic arms and tools without even having to be in the operating room. The console itself is composed of three parts: a visual display, a foot pedal for camera manipulation, and a master controller that captures the movement from the surgeon’s hands [3]. At the end of the controller are attachments that resemble surgical tweezers, which the surgeon manipulates using his thumb and index finger. The movement of these tweezers are then translated to move the tools at the operating table.
Since medical procedures often require the surgeon to be concentrated for several consecutive hours, the console was designed to be as comfortable as possible. The seat and control handles can be adjusted to provide an ergonomic workplace for the surgeon during the operation. Also, the console has arm and head rests that improve comfort levels for the surgeon and help avoid fatigue during long procedures (Fig. 3).
Robot Arms and EndoWrist® Instruments
The robot cart is placed at the operation table, separate from the surgeon’s console. One of the robotic arms holds the camera, while the other three arms hold the special da Vinci robot tools, or EndoWrist® instruments (Fig. 4). In order for the robotic limbs to perform the operation inside the patient’s body, incisions of 3-12 mm in length are made (a significant improvement from the typical 10-40 cm incision made during a traditional open surgery). These less invasive incisions dramatically decrease the area of the patient’s body that is exposed to the outside environment, thus decreasing the risk of an infection and significantly reducing the size of postoperative scars. The smaller incision points also reduce blood loss and lead to an easier and speedier recovery for the patient [6].
The Endowrist® instruments provide for the surgeon a multitude of surgical tools. The surgical tools can be exchanged throughout the surgical procedure by a bedside surgeon [4]. Some of the instruments provided include the traditional surgical tools such as a forceps and the curved scissors (Fig. 5), as well as more specialized and surgery-specific devices, which allow for minimal equipment exchanges during a surgical procedure [4]. The tools offer seven degrees of mobility, meaning that they are capable of surpassing the limits of the human wrist [3]. With such a wide range of motion, the surgeon is able to perform maneuvers that would be impossible to accomplish with his own hands [3].
The robotic arms and the computer system also reduce the physiological tremor produced by the human hand. Since even the smallest vibration could result in a surgical failure, it is imperative that any hand shaking is filtered out so that surgeries can be more exact. The computer system can also scale the motion of the surgeon, enabling him to work in smaller areas yet still have a comfortable range of motion [7].
InSite® Vision System
In order to provide surgeons with a clear and three dimensional picture of the operation, a special imaging technique is used. The InSite® Vision system consists of two high-resolution cameras and two light sources that capture images of the surgical area from two different angles (Fig. 6). The two images are then synchronized and shown on the surgeon’s console as a stereoscopic, three-dimensional image [3]. In addition to constructing a three-dimensional view of the operation, the vision system is also able to magnify the image up to 10 times the original scale [3]. The magnified image enables the surgeon to manipulate smaller areas with increased precision and accuracy.
In order to control the camera movement, the surgeon must press down on the console’s foot pedal, which picks up and moves the cameras. The surgeon then uses the master controller to direct the movement of the camera inside the patient [6].
The Limitations of Robotic Surgery
Though the da Vinci robot offers a multitude of technological tools to make minimally invasive surgeries a viable option, there are still several issues that must be addressed. Not unlike any other technique in the medical field, the da Vinci robotic system requires extensive training in order to be mastered. It is estimated that surgeons must undergo over 1,600 robotic surgical operations before they can perform with a high success rate [8]. This implies longer training times and more resources expended in training surgeons.
Also, surgeons have no tactile feedback and cannot physically feel the tissue and area they are working in. Moreover, robotic surgery offers a limited view of the surgical area and does not expose the areas above and below the view provided by the camera [5]. Though there currently are severe limitations to robot-assisted surgeries, it is important to continue striving for new technologies to automatize the operating room, as they may one day completely change the course of surgical medicine for the better.