maxon Story
State-of-the-art surgical robots.
Critical components used in the latest versions of the da Vinci™S HD surgical system include the high-quality motors that run smoothly even at extremely low speeds.
The latest, next generation surgeries are being performed today using Intuitive Surgical Inc.’s (Sunnyvale, CA, USA) da Vinci™S HD surgical system, which allows surgeons to perform minimally invasive procedures. The system incorporates state-of-the-art motion control technologies so that every motion of the surgical instruments provides the smooth, extremely accurate movements reminiscent of the hand of a skilled surgeon – even at extremely slow speeds. Intuitive Surgical has continued to upgrade its da Vinci S HD System, consistently using the best components and controls on the market. The da Vinci S HD thus remains able to perform highly complex operations that save lives. Each da Vinci S HD system contains 39 maxon motors.
A high-precision surgical system
The surgical system itself requires only three small incisions 8 to 12 mm wide, to insert a camera and two manipulator arms carrying surgical instruments into the body of the patient. Only the robot and surgical assistants stand over the patient, while the surgeon can be across the operating room, controlling the system from the surgeon’s console where the look and feel of real surgery is duplicated with very high precision.
The da Vinci S HD surgical robot is designed to integrate perfectly into the operating room, and to give optimum support to the surgical team, just as every other participant in the operation is expected to do. The whole system consists of three main components: the surgeon’s console, a patient-side cart that holds the instruments, and the image processing module.
The surgeon’s console is central to the da Vinci S HD surgical system. There, the surgeon controls every moment of the operation. Trials with other kinds of techniques using a video transmission system proved less effective. The main challenge was the directional reversals that 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 learned by the surgeon through experience.
Through the use of the da Vinci S HD surgical system, the surgeon is able to perform the operation while seated comfortably at a console, viewing an unparalleled 3D high-definition visualization of the surgical field. As the world’s first robotic surgical system with high-resolution 3D HD vision, the system provides twice the effective viewing resolution of older models to now offer improved clarity and detail of tissue planes and critical anatomy. The InSite™ vision system, the high-resolution 3D HD endoscope, and the image processing module provide 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 (controls that replicate surgery motions). The surgeon's fingers grasp the master controls below the display with wrists positioned naturally relative to his or her eyes. Then, the surgeon’s movements are seamlessly translated into precise, real time movements, transmitted to the instruments at work inside the patient.
The robotic manipulator arms, carrying the surgical instruments, are controlled by the surgeon through wrist, hand, and finger moves just as a conventional surgery would be. An extensive range of EndoWrist™ instruments is available for the system. These endoscopic instruments are designed with seven degrees of motion that mimic 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. A third robotic arm can be installed as an option. It allows surgeons to utilize an additional endoscopic instrument and further enhance surgical capabilities. The laparoscopic instruments pivot at the operating ports, 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 insertion of the probes into the patient’s body, and supervise the laparoscopic arms and tools being used.
maxon motors selected for their extreme reliability
Absolutely precise motion control is necessary when manipulating robotic surgical tools through small (8 to 10 mm) incisions to perform an operation inside the patient's body. At the heart of each manipulator are DC motors designed and manufactured by maxon.
According to Mike Prindiville, Manufacturing Engineering manager at Intuitive Surgical, “While there are many options available on the market, maxon has 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 that are essential to the da Vinci S HD system. Through a series of feedback controls, the motors and encoders receive inputs from the surgeon, which are translated in real time through the console electronics, and transformed into 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 Surgical engineers have integrated over 30 maxon motors in the design, including RE 25 motors, some with and some without encoder feedback; RE 13 motors equipped with GP 13 series planetary gearheads and 13 mm magnetic encoders; and RE 35 motors with third party encoders.
maxon motors are designed with rare earth magnets in their stators and incorporate an ironless rotor design, thus eliminating magnetic cogging. Especially at slow operating speeds, this represents a considerable advantage compared to conventionally designed motors. The motors also offer unparalleled power density and extremely smooth rotation, both of which are essential to the Intuitive Surgical application.
The motors used on the surgeon’s console are called masters to distinguish their dual role. The slave drives, installed in the manipulators, have the same precision, but can also be backdriven while an assistant surgeon moves the end effectors into position. The motors also exhibit low hysteresis at the instrument tips.
Intuitiveness, full range of motion, and latest technologies
The da Vinci S HD surgical system is the only commercially available technology that can provide the surgeon with the intuitive control, full range of motion, fine tissue manipulation capability, and 3D visualization characteristic of open surgery, while simultaneously allowing the surgeon to work through small ports of minimally invasive surgery. The use of the latest technologies in the motors and other components allows such systems to enter the marketplace.
The da Vinci S HD surgical system is based on foundational technology developed at SRI (formerly known as Stanford Research Institute) for computer-assisted surgery. Intuitive Surgical later formed relationships with IBM, Massachusetts Institute of Technology, and Heartport, Inc. to further develop the da Vinci S HD system. The American FDA (Food and Drug Administration) has approved this surgical system for use in such abdominal surgery as bladder and colon surgery, for chest surgery excluding the heart, and for prostate surgery. In Europe, the da Vinci S HD System is already used for heart bypass procedures.
According to Mike Prindiville, Manufacturing Engineering manager at 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 unfailing 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.”