Overview
The latest, next generation surgeries are being performed today using Intuitive Surgical Inc.'s (Sunnyvale, CAA) da Vinci™™S HD Surgical System, which allows surgeons to perform the most minimally invasive procedures to date. This robot-assisted surgery from Intuitive Surgical has helped surgeons overcome the limitations off manual laparoscopy.
Laparoscopy uses long instruments inserted through small incisions. Compared with traditional open procedures, laparoscopy has revolutionized the treatment of abdominal pathologies by shortening recovery time with less pain and fewer adhesions, resulting in better postoperative quality of life. However, manual laparoscopy has also revealed several limitations, including lack of depth perception, poor camera control, limited degrees of freedom for the instrument tips, and inverted hand-instrument movements. These limitations lead to unnatural and painful surgical postures that result in surgeon fatigue.
In robot-assisted laparoscopy, the surgeon sits at a console and remotely controls endoscopic instruments via a surgical robot. The 3D visualization provides depth perception, and the wrist-like articulations of the console instruments improve surgeons' dexterity by diminishing tremor and scaled motion and increasing range of motion. The coordinated hand-instrument movement reduced laparoscopic surgeon training time using robotic systems in comparison to using manual laparoscopy. The dVS has been approved by the FDA for gastrointestinal, thoracic, urological, gynecological, and cardiac procedures.
The Surgical System
The surgical system itself requires only the use insertion of the two surgical manipulators and a camera. Only the robot and surgical assistants stand over the patient, while thee surgeon, the system operator, can be across the room at the Surgeon's console where even the look and feel of the open surgery is duplicated with precision.
The da Vinci S HD Surgical System was designed to be integral to the operating room. It had to support the entire surgical team; just as every other member of the operation is expected to do. The whole system consists of three distinct components, which includes the surgeon console, patient-side cart that holds the instruments, and the image processing equipment.
The Surgeon Console is central to the ability of the da Vinci S HD to perform operations. Other attempts at performing surgery while using video proved difficult. The most prevalent challenge was that of directional reversals the surgeons had to deal with. Think of tying your shoes with chopsticks. When you move the chopsticks to the left, the tip moves to the right. That's the counter-intuitive movement that is experienced in traditional laparoscopic surgery. At one time these counter-intuitive movements needed to be overcome by the surgeon through experience.
Through the use of the da Vinci S HDD Surgical System, thee surgeon is able to perform the operation while seated comfortably at a console viewing an unparalleled 3-D HD visualization of the surgical field. As the world's first robotic surgical system with 3D HD vision, the system provides twice the effective viewing resolution than older models too now offer improved clarity and detail of tissue planes and critical anatomy. The InSite™ Vision System, the High resolution 3-D HD Endoscope and Image Processing Equipment used by the system provides true-to-life images of the operative field. Operating images are enhanced, refined, and optimized using image synchronizers, high-intensity illuminators and camera control units.
Also at the console, the surgeon performs movements using masters (that replicate surgery motions). The surgeon's fingers grasp the master controls below the display with wrists naturally positioned relative to his or her eyes. Then, the surgeon's movements are seamlessly translated into precise, real time movements inside the patient.
The robotic manipulators are controlled by the surgeon through wrist, hand, and finger moves just as a typical surgery would be. A full range of optional EndoWrist Instruments are provided for the system. These instruments are designed with seven degrees of motion that mimics the dexterity of the human wrist. Each instrument has a specific surgical mission such as clamping, suturing, and tissue manipulation.
The patient-side cart houses the two robotic arms and one Endoscope arm, which duplicate the surgeon's movements. System options are available for a third robotic arm, allowing surgeons to utilize an additional endoscopic instrument and further enhance surgical capabilities. The laparoscopic arms pivot at the operating port, eliminating the use of the patient's body wall for leverage. This minimizes tissue and nerve damage. Supporting surgical team members install the correct instruments, prepare the port in the patient, and supervise thee laparoscopic arms and tools being used.
Sophisticated Actuation
The da Vinci S HD Surgical System incorporates the height of motion control technologies so that every motion provides the smooth, accurate movements reminiscent of a skilled surgeon——even at slow, calculated speeds. Over the past few years, as technological advances continue in the motion control industry, Intuitive Surgical has continued to upgrade its da Vinci S HD System using the best components and controls on the market to produce the da Vinci S HDD, which continues to perform life-saving operations. Each da Vinci S HD System contains over thirty motors manufactured by Maxon Precision Motors (Fall River, MA). These motors are located at the heart of each manipulator.
According to Mike Prindiville, Manager, Manufacturing Engineering for Intuitive Surgical, "While there are many options available on the market, Maxon Motors have consistently met our demands for performance and quality, and been a strong partner in the success of our product." The Maxon motors provide the inputs and outputs to the da Vinci S HD System. Through a series of feedback controls, the motors and encoders receive inputs from the surgeon, are translated in real-time through the console electronics, and provide output signals to the motors in the manipulators. In turn, the manipulators exert forces back through the console electronics to the surgeon's hands.
Intuitive engineers have designed in over thirty Maxon motors, including RE 25 motors, some with and some without encoder feedback; RE 13mm motors equipped with GP 13 series gearheads and 13mm magnetic encoders; and RE 35 series motors with third party encoders.
Maxon motors are designed with rare earth magnets in their stators and incorporate an ironless rotor design that eliminates magnetic cogging, even at slow operating speeds. The motors also offer good power density and smooth rotation, both of which are important to the Intuitive application.
The motors used on the surgeon's side cart are called masters to distinguish their dual role. The slave side, or manipulator motors, required the same precision, but also needed to be able to be backdriven while an assistant surgeon moved the end effectors into position. The motors also exhibit low hysteresis at the instrument tips.
Sophisticated Training
Although the prevalence of robot-assisted surgery has tremendously increased, the development of training protocols is limited. Surgeons previously equipped with only their two hands must now master the manipulation of an extensive variety of remotely-operated surgical tools. Comprehensive practice and experience is necessary in order to develop proficiency with a sophisticated tool such as the da Vinci S HD. Thus, establishing training programs for robotic assistive surgery will be critical in helping meet the demand for the advancing technique.
At the Nebraska Biomechanics Core Facility in the HPER Biomechanics Laboratory at the University of Nebraska at Omaha, a group of PhD students worked with the Robotic Surgical Laboratory at the university's medical center to develop a training program for robotic surgery where new surgeons can learn how to use this advanced technology.
Two training platforms were developed with National Instruments LabVIEW graphical programming software. The first is designed for monitoring and recording a surgeon's performance during a training program and ensuring that the surgery is performed using the correct movements. This training platform also incorporates visual real-time feedback to show trainees how much force they apply on the training task or animate tissue. This visual feedback helps trainees reduce tissue damage inflicted during the procedure.
NI LabVIEW was also used to create a working environment for training in virtual reality. This second training platform offers flexibility to conduct research by collecting data and adjusting training tasks in the virtual simulator via Ethernet. Virtual robotic surgical training opens a new realm of possibility where multiple surgeons can train simultaneously and provide problem-based training protocols for new surgeons to learn robotic surgery. With LabVIEW, it was easy to continuously improve the training system because of the modular approach of software-defined hardware.
All of the information from the robotic surgical system is acquired by connecting with the dVSS via TCP/IP. The National Instruments USB-6009 data acquisition board was used to connect to the electromyography system and electrogoniometers to acquire physiological measurements such as muscle activations and joint angles from the surgeons.
With this system, researchers and medical personnel can objectively evaluate surgical proficiency before and after the robotic surgical training protocol. The application assists in training doctors on a system that mutually benefits doctors and patients alike by reducing surgeon fatigue and minimizing tissue damage inflicted during laparoscopic procedures.
Conclusion
The da Vinci S HD Surgical System is the only commercially available technology that can provide the surgeon with the intuitive control, range of motion, fine tissue manipulation capability, and 3-D visualization characteristic of open surgery, while simultaneously allowing the surgeon to work through small ports of minimally invasive surgery. The sophisticated training program for surgeons and the availability of motors and other components that are designed and manufactured using the latest technologies allows such systems to enter the marketplace.
The da Vinci S HD Surgical System is based on foundational robotic surgery technology developed at SRI (formerly known as Stanford Research Institute). Intuitive Surgical later formed relationships with IBM, Massachusetts Institute of Technology, and Heartport, Inc. to further develop the da Vinci S HD System. The FDA had approved the system for use in such abdominal surgery as gall bladders and colon surgery, for chest surgery excluding the heart, and for prostate surgery. The da Vinci S HD System is already used in Europe for heart bypass procedures.
According to Mike Prindiville, Manager, Manufacturing Engineering for Intuitive Surgical, "On any given day, we rely on 10,000+ Maxon motors to deliver patient, surgeon, and hospital value all over the world. Maxon motors have demonstrated a proven track record of reliability, low friction, and extended life. Each da Vinci System is tested for critical performance characteristics, including friction, backlash, and compliance profiles, and a wide range of sensor feedback monitoring."