Embarking on a Fantastic Voyage
Technology has made it possible for medical robots to evolve from the pages of science fiction novels to operating rooms.
Michael Barbella
Although microscopic-sized humans (and sexy female scientists) are still strictly science fiction fodder, the notion of treating medical conditions by actually entering the human body through tiny machines or robots is one that is no longer limited to the imagination. Advances in technology over the last four decades has enabled biomedical researchers to develop devices that can journey through the body to diagnose disease, deliver drugs or perform surgery.
The most clinically advanced devices have been developed for the digestive tract, which is easily accessible and can accommodate objects several centimeters in size. One of the pioneers of these gastrointestinal Magellans is Given Imaging, an Israeli firm that developed the PillCam, a capsule equipped with a tiny camera for recording images (via computer) of the GI tract and intestines.
Measuring 1.1 cm in diameter and 2.6 cm in length, the vitamin-sized device transmits pictures at a rate of two images per second and can generate more than 50,000 pictures over an eight-hour period. The device provides both doctors and patients with an alternative diagnostic tool, but there is some uncertainty about its ability to detect cancerous growths in the colon. Despite a study funded by Given Imaging concluding that the PillCam is less effective than standard colonoscopies at finding precancerous polyps and cancer, the PillCam has become widely used by physicians since its approval by the U.S. Food and Drug Administration (FDA) in 2001.
Technological advances over the last four decades have allowed doctors to operate on patients using robotic devices such as the da Vinci Surgical System, pictured above. Last year, 136,000 procedures were performed with the da Vinci System, up 60 percent from 2007. Photo courtesy of Intuitive Surgical, Inc. |
Before these capsule robots can do any of those things though, scientists must figure out how to overcome the challenge of miniaturization. Hollywood conquered this challenge by having its scientists invent a large contraption called a Miniaturizer that reduces the size of any type of matter within seconds (“Our Miniaturizer can shrink anything!” one of the characters in “Fantastic Voyage” proudly exclaims). In the real world, however, miniaturization is not so easily rectified. For starters, the robot’s entire technology, including the power supply, must be housed within a few cubic millimeters. Considering that the batteries in existing micro-cameras take up 60 percent of the capsule’s volume, such a feat poses quite a challenge.
A team of researchers from France, Italy, Spain and Switzerland, however, is working on a solution. The team, called ARES, is experimenting with a way for multiple capsules to magnetically snap together once they are inside the stomach. Each capsule (swallowed separately) would perform a different task once it is inside the body. One would take images; another would power the device; a third would take tissue samples; and others would perform various other jobs as needed. The capsules are polarized at right angles to the surface, so they attach themselves in the correct order in the stomach.
The ARES team tested its self-assembling robot in an artificial stomach with a 75 percent success rate.
The CyberKnife Robotic Radiosurgery System has helped more than 60,000 patients worldwide fight tumors in various parts of their bodies since its introduction to the market in 1999. Photo courtesy of Accuracy Inc. |
Magnetism is proving to be a powerful tool in helping researchers overcome the limitations of miniaturization. Besides using magnetic fields to link capsule-sized cameras, researchers are using the laws of attraction to develop a steering system for these devices. Scientists with the Institute of Robotics and Intelligent Systems at the Swiss Federal Institute of Technology in Zurich, Switzerland, are hoping to use external magnetic fields to steer tiny robots inside the eye for sensing, drug delivery and surgery. The robots contain magnetic material and would be navigable by controlling the magnetic fields surrounding it. Researchers at the institute have designed a special opthalmoscope to track these robots inside the eye.
Sylvain Martel and his colleagues at the NanoRobotics Laboratory of École Polytechnique de Montréal in Canada are using magnetic fields as well to guide medical robots but are enlisting the help of magnetic-resonance imaging machines to propel small beads through the bloodstream. Martel hopes to use the electromagnetic forces to deliver medicine to specific areas of the body.
There are, however, some disadvantages to using magnetic fields to power robotic devices in the body. The most important of these is control. Without the proper control of the fields, micro-robots could veer significantly off course, resulting in harmful or possibly fatal consequences inside the body.
As the Australian researcher works to perfect the tiny, flagella-powered robots, a team half a world away in Tel Aviv, Israel, is building a “submarine” that will rival the vessel featured in “Fantastic Voyage.” Composed of biological materials, this real-life version of the Proteus (the vessel carrying the surgical task force in “Fantastic Voyage”) ditches its human cargo for drugs that can kill cancer cells and eliminate faulty proteins.
The team, led by Dr. Dan Peer of the Department of Cell Research and Immunology at Tel Aviv University, plans to pair its “submarine” with various RNAi compounds to target such diseases and disorders such as cancer, inflammation, and neurodegenerative conditions. Peer’s team plans to launch its medical submarines (following FDA regulations, of course) within three to five years.
Robotics' Recent Rise in the O.R.
Biological “submarines,” minuscule magnetic beads and self-assembling robotic surgeons certainly will make for a promising and exciting future in health care. But that future is still several years away at best.
As scientists work to fine tune the mechanical devices that may one day perform surgery or examine diseased tissue while inside the body, doctors are increasingly using robotic devices in the operating room to boost the accuracy of surgical procedures and improve patient outcomes.
“Robotic surgery really is just the natural progression or the next advancement of laparoscopic surgery,” said Stuart R. Geffner, M.D., director of Kidney and Pancreas Transplant Surgery for Saint Barnabas Health Care System’s Renal and Pancreas Transplant Division in Livingston, N.J.
While the concept of robotic surgery has existed for decades (at least on film, anyway), scientists and engineers have only recently been able to translate such a revolutionary idea from the silver screen to the operating room.
Doctors experimented sporadically with robotic devices in the 1980s, using machines with futuristic-sounding names like the PUMA 560 and the PROBOT (the latter was used to perform prostatic surgery). More of these machines began to pop up in the 1990s to help surgeons replace joints, reconnect fallopian tubes and perform heart bypass surgery.
It took until the turn of the millennium, however, for medical robots to be considered a viable (and safe) alternative to traditional surgery. In 2000, the FDA approved a robotic device called the da Vinci Surgical System for general laparoscopic surgery. Developed by Sunnyvale, Calif.-based Intuitive Surgical Inc., the da Vinci Surgical System (aptly named after the inventor of the first robot) consists of a small motorized cart with four arms. One of the arms holds a camera and the other three arms hold the surgical instruments necessary for surgery. A second unit, where the surgeon sits, is connected to the robot.
The da Vinci System gives surgeons a three-dimensional image of the work area through a viewfinder at the console. The image mirrors what physicians would see during traditional open surgeries, though some experts argue that the device actually enhances visualization.
“The da Vinci System offers surgeons obvious advantages in the areas of visualization, precision, dexterity, control and ergonomics through its 3-D vision system and EndoWrist instruments, as well as robotic-assisted and computer-enhanced technologies,” said Nora Distefano, market development specialist at Intuitive Surgical. “These advances are a distinct advantage for surgeons relative to existing laparoscopic and endoscopic technology.”
One of the key features of the da Vinci System that has helped make it a popular choice among surgeons is its ability to precisely mimic the operator’s motions. If, for example, a surgeon makes a pinching motion with his or her fingers, the instrument at the end of the machine’s “arm” will immediately pinch whatever object it is grasping.
Another unique feature of the da Vinci that its creators like to tout is the enhanced mobility of the
Proponents of robotic surgical devices claim the machines provide surgeons with an increased range of motion, improved dexterity, enhanced visualization and better access. Photo courtesy of Intuitive Surgical Inc. |
device’s “wrists.” The system’s EndoWrists move 360 degrees, providing surgeons with better mobility than their own joints and making it easier for them to access and maneuver in smaller, more intricate areas of the body such as the bladder, prostate or kidney.
Geffner can attest to the accessibility and maneuverability of the da Vinci System. He used the device to perform the world’s first robotic-assisted kidney transplant shortly before Christmas last year.
“Laparoscopic instruments really only move in two planes. They move in and out and the jaws open and close, kind of like a scissors opens and closes. If you want to move the instrument an inch you have to move your hand an inch because it’s directly connected to the surgeon’s hand,” Geffner told Medical Product Outsourcing. “Robotic instruments are different. They wrist and turn the way your hands wrist and turn, so they move in three dimensions as opposed to the two dimensions laparoscopic instruments move in.
Robotic devices enable you to make very, very fine movements—finer movements than you could with your hand. They also remove the natural tremor that everyone has. So the combination of better visualization, the wristing, the 3-D movements of the instruments and the ability to make very fine movements with instruments made me realize we could now do certain things robotically that we could not do laparoscopically.”
Namely, the fine suturing when connecting blood vessels, which is a vital part of any kidney transplant. Though he had performed donor surgeries using the da Vinci System, Geffner said he practiced on a variety of materials and in an animal lab before trying the actual transplant procedure on a human patient. He also performed different parts of the procedure on patients before conducting the groundbreaking surgery on a diabetic woman at Saint Barnabas Medical Center.
Saint Barnabas is one of 916 hospitals throughout the nation that have the da Vinci System. Its prevalence can be attributed to the fact that Intuitive Surgical is the only manufacturer of a robotic-assisted medical device for use in minimally invasive soft-tissue surgery. Earlier this year, the company introduced the da Vinci Si Surgical System, an upgrade to its existing systems that features enhanced 3D high-definition resolution, an updated and simplified user interface to enhance operating room efficiency, an optional dual console that allows a second surgeon to assist during surgery or observe the procedure, and new ergonomic settings to the surgeon console.
Robotics Market Becoming More Crowded
The success of Intuitive Surgical’s da Vinci System over the last nine years has prompted other companies to design robotic or computer-assisted devices in the hopes of scoring similar victories in the market.
MAKO Surgical Corp. of Fort Lauderdale, Fla., has developed a robotic arm system that cuts down on recovery time and pain for patients undergoing knee resurfacing. The robotic arm resurfaces the knee while a stereo camera system updates the surgeon about the precise location of the diseased part of the knee. If the surgeon gets too close to healthy tissue, audio and visual alarms sound, and the robotic arm gives resistance so the doctor feels as if he or she has hit a wall.
MAKO, however, is not alone in its use of robotics in orthopedic surgery. CUREXO Technology Corporation of Fremont, Calif., has developed a device called the ROBODOC Surgical System, which allows doctors to pre-operatively plan their surgery in a 3-D virtual space and then execute the procedure exactly as planned in the operating room.
Pre-dating both MAKO and CUREXO’s products though, is the CyberKnife Robotic Radiosurgery System from Accuracy Inc. When it was approved by the FDA in 1999 for the treatment of head, neck and upper spine tumors, the device was the first and only commercially available radiosurgery system to combine image guidance and computer-controlled robotics, according to the Sunnyvale, Calif.-based firm.
In 2001 (the same year Intuitive Surgical received approval for its da Vinci System), the FDA approved CyberKnife Radiosurgery for the treatment of tumors anywhere in the body. Since then, the company has received FDA approval for systems that enable doctors to track, detect and treat tumors in the lung, liver, pancreas and spine.
CyberKnife Radiosurgery is not actually a knife, but rather a radiation tool that can destroy tumors and lesions without surgery, pain, anesthesia or long recovery times. “CyberKnife [Radiosurgery] is able to accomplish an equivalent and perhaps superior treatment because it is not limited by the ability to remove critical tissues,” said Gregg A. Dickerson, M.D., F.A.C.R., and specialist in CyberKnife Radiosurgery at Denver CyberKnife, a radiation therapy center based in Colorado’s capital city. “We can radiate them. It’s a very surgical modality rather than a radiation tool. It’s more of a surgical instrument.”
CyberKnife Radiosurgery uses image guidance software to track and continually adjust treatment for any patient or tumor movement, allowing patients to breathe normally and relax comfortably during treatment. Before treatment, the patient undergoes imaging procedures (usually CT scans) to determine the size, shape and location of their tumor.
After the scanning is completed, doctors transfer the image data to the system’s workstation, where they identify the exact size, shape and location of the tumor to be treated. Doctors also identify the surrounding healthy tissue to be spared doses of radiation.
Once a treatment plan is created, the patient lies on a table for radiation treatments that last between 30 and 90 minutes. The treatment typically involves the administration of between 100 and 200 radiation beams delivered from different directions, each lasting 10 to 15 seconds. Before each beam of radiation is delivered, the CyberKnife Radiosurgery system simultaneously takes X-ray images and compares them to the original CT scan. This image-guided approach continually tracks, detects and corrects for any movement of the patient and tumor during the treatment process.
“CyberKnife Radiosurgery costs 30 percent to 50 percent less than a dose of radiation delivered the traditional way,” Dickerson noted. “It is a tremendous cost savings to the health care system. And patients love it. They don’t have complications afterward, they go on with their lives.”
SIDEBAR
Robotics' Fight for Acceptance
Michael Barbella
Todd D. Tillmanns, M.D., no longer lets an intolerance of robotic surgery annoy him.
“My hope is other doctors will adopt this technology for their patients’ care and I will be there if they need me and I will be their best advocate,” said Tillmanns, a gynecological oncologist at The West Clinic in Memphis, Tenn.
Despite the advocacy of Tillmanns and a growing number of other surgeons, however, many doctors remain skeptical of robotic surgery. They consider the technology to be intriguing but believe it has no place in the operating room.
Robotic surgery uses three-dimensional imaging and instruments that mimic a doctor’s wrist, thereby helping physicians overcome the challenge of mastering counter-intuitive hand movements. The robotic system eliminates hand tremors and lets the surgeon sit during the procedure, which can help reduce fatigue.
One of the reasons for doctors’ skepticism about robotic surgery is the lack of long-term clinical data. While the technology has been in development for decades, it did not receive the blessing of the U.S. Food and Drug Administration (FDA) until 2000. In July of that year, the FDA approved the first robotic surgical device—the da Vinci Surgical System. The product helped revolutionize surgery and prompted the development of other robotic and computer-assisted devices, such as the ROBODOC Surgical System by CUREXO Technology Corporation of Fremont, Calif., a robotic arm system from MAKO Surgical Corp. of Fort Lauderdale, Fla., and the CyberKnife Robotic Radiosurgery System from Accuracy Inc.
These products, however, have done little to change doctors’ attitudes toward robotic surgical devices. Advocates have been touting the benefits of these devices for years, saying robotic systems help patients recover quicker from surgeries and leaves them with smaller, less visible scars. And, studies have shown that robotic surgery patients have shorter hospital stays and need less pain medication in the first 24 hours after their procedure. But without long-term data, many doctors are still not convinced that robotic procedures are any more beneficial than traditional operations.
“What we really need to know is if this holds up long term,” said Arnold P. Advincula, an M.D. from the University of Michigan who moderated a robotic surgery session in May at the American College of Obstetricians and Gynecologists’ 57th Annual Clinical Meeting in Chicago, Ill.
“In cancer surgery, studies show that you can obtain a better surgical dissection, particularly for lymph nodes, but we don't know the five-year survival rates,” he said.
Training also has become a thorny issue. The FDA requires one- to two-day training to certify that a surgeon can use a robotic system, but certification does not guarantee a doctor’s proficiency in a particular system, industry experts said.
Issues such as the lack of uniform training standards are not uncommon to industries still in their infancy. Robotic surgery proponents, however, are working to address these issues through the professional organizations they recently have formed to promote and support the growth of the technology.
The Minimally Invasive Robotics Association was founded in 2004 to “raise the level of robotic surgery care,” according to its Web site (www.mirasurgery.org). The Los Angeles, Calif.-based organization also disseminates information about the performance and “perfection” of robotic surgery, as well as facilitates the exchange of information about the technology between interested doctors.
In August, a group of surgeons launched the Clinical Robotic Surgery Association (CRSA), an organization that is described as an “international think tank and discussion forum to support the growth of robotic [surgery].”
“It’s our vision that CRSA will become an organization where robotic surgeons from all over the world can work together in a cohesive effort to further the development of robotic surgery innovations,” said Pier Cristoforo Giulianotti, M.D., chief of general, minimally Invasive and robotic Surgery at the University of Illinois in Chicago. The group, which held its first international conference in Chicago earlier this month, plans to develop an online training center where surgeons worldwide can access videos of robotic surgeries and discuss innovative approaches to different surgical techniques.
Such a collaborative approach to learning and the exchange of ideas was the driving force behind the creation of The Memphis Robotic Surgery Society in Memphis, Tenn. Besides acting as an outlet for collaboration, the society is designed to help train healthcare workers, inform patients and gather clinical data about robotic technology.
“I have always thought the mission of medicine should be collaborating to provide the very best care to patients,” explained Tillmanns, the society’s president. “The idea behind the society was to have different kinds of surgeons get together and learn from each other. We bring together a whole society so when a patient says ‘I want robotic surgery done,’ there’s a whole group of surgeons in town for the patient to choose from instead of one surgeon monopolizing all the patients. Instead of being an impediment to each other, we’re all helping each other.”