A Cut Above: Robotics in Surgery

What began as a prototype system for performing battlefield surgery under contract to the US Army now offers thousands of patients shorter hospital stays, less scarring and a faster return to normal life after major surgery.

The da Vinci surgical systems from Intuitive Surgical Inc. of Sunnyvale, Calif., are the only commercially available robotic systems that can be used to carry out minimally invasive, soft tissue surgery. Such robots afford surgeons greater precision, increased range of motion, enhanced visualization and improved access to tissues. After becoming the first robotic surgical system cleared by the FDA for general laparoscopic surgery in 2000, more than 1500 units have been shipped to more than 30 countries.

The da Vinci Si HD surgical system offers dual consoles, enabling two surgeons to collaborate. The patient side cart, pictured here, has four instrument arms, which facilitate this collaborative effort. Three of the arms hold instruments, and one holds the endoscope. Images courtesy of, and ©2010, Intuitive Surgical Inc.

Robotic-assisted surgery enables surgeons to perform many more major procedures using much smaller incisions – typically 1 to 2 cm. But as with any minimally invasive operation, vision and imaging become all the more essential. With some of the latest imaging technology onboard, the third generation, and the latest in the line of da Vinci surgical systems, the da Vinci Si uses two high-definition cameras to bring a crucial aspect back to surgeons: depth perception.

Although traditional laparoscopic, or keyhole, surgery is minimally invasive, one drawback is that it limits the surgeon’s view to 2-D images displayed on a television screen. Open surgery, on the other hand, provides surgeons with a 3-D view but requires a large incision, which means more scarring for the patient and a longer recovery time.

Today’s robotic-assisted surgery machines combine the best of both by restoring the surgeon’s 3-D view while maintaining a minimally invasive approach. The da Vinci Si encompasses a custom dual-lens endoscope coupled with two three-chip cameras to effectively take the surgeon “inside” the patient. The high-resolution 3-D endoscope has two independent vision channels linked to two high-resolution progressive-scan color monitors.

A surgeon uses the da Vinci surgical system console.

Merging the two images provides the surgeon with accurate depth perception. The system also incorporates image processing equipment comprising high-performance video cameras, and edge-enhancement and noise-reduction equipment.

“The resulting high-resolution 3-D image is bright, crisp and clear, with no fatigue-inducing flicker or cross-fading, as with single-monitor systems,” said Nora Distefano, market development specialist at Intuitive Surgical. “Camera control is provided through hand controls and foot pedals … [offering] near-seamless transition between views. Repositioning your head at the console does not affect image quality, as with other 3-D display systems.”

When you think of robots in the operating theater, you can’t help but imagine long metallic arms hovering above the surgical table mechanically repeating a series of steps programmed into an electronic brain. But this is a common misconception. Today’s robotic systems are simply tools to aid the surgeon. As with a scalpel or a laparoscope, the robots are an apparatus designed to enhance the surgeon’s capabilities, but they remain completely under the surgeon’s control.

By mimicking the surgeon’s hand, the robotic arm can carry out complex procedures such as excising and suturing within the body. Couple this with 3-D magnified views provided by high-definition cameras, and you have a powerful medical instrument that can operate through tiny incisions.

Public acceptance of robotic-assisted surgery seems to be mixed. Some believe it to be a natural progression of technology in the medical field, while others see it as a step too far. But for Gregory S. Fischer, assistant professor of the robotics engineering program and director of the Automation and Interventional Medicine Robotics Research Laboratory at Worcester Polytechnic Institute in Massachusetts, the bigger question is related to acceptance by doctors.

“For the technology to take off, I think it will require some significant new applications, where procedures can be done with robots that cannot be done – or done safely – otherwise,” he said. “Incremental improvement with slightly faster or better results won’t provide enough incentive for adoption.”

This image shows engagement of the robotics system with the patient. Images on this page courtesy of Dr. Hiep T. Nguyen.

Another possible barrier to adoption is the cost of the robotic units. Dr. Hiep T. Nguyen, director of the Robotic Surgery, Research and Training Center at Children’s Hospital Boston, said that at a cost of between $1 million and $2.3 million, a hospital must think seriously before purchasing one.

“The price of a robotic system is exorbitantly high,” he said. “We’ve looked at the cost of utilizing robotic surgery compared with open surgery, and in some cases it is beneficial, because if you can minimize hospital stay, you can make up for the price of the instrument. However, what’s going to limit the use of the robotic system in medicine for sure is the price.”

Children’s Hospital Boston was the first of its kind to use the robotic system – about a decade ago – and has since invested in the da Vinci Si. Besides offering 3-D imaging, the Si provides two consoles, enabling two surgeons to operate at once.

The dual console allows for two surgeons to operate simultaneously. Image courtesy of Dr. Hiep T. Nguyen.

“Being the director, I am responsible for making recommendations to the hospital, and what really attracted me to [the da Vinci Si] was the availability of a second console,” Nguyen said. “This is extremely important when doing very complicated cases, and, oftentimes, having another hand, as you have in open surgery, is very beneficial. Also, because we are a training center, we really felt it was important to use the second console to help teach residents and fellows without any sacrifice to patient safety.”

But the only way to bring the cost of units down is by encouraging competition in the marketplace, Nguyen said. New technologies are already in the pipeline that not only involve advanced imaging but also explore the possibility of giving surgeons back their sense of touch.

Object recognition and 3-D tracking have come a long way and allow localization of targets and critical structures, Fischer said. Tracking enables registration of medical images with video signals, to allow augmented reality image overlay. Sensing can include tactile sensing for haptic feedback or optical sensing for analyzing tissue properties and guiding an intervention.

“The integration of real-time tomographic imaging has allowed for interactive localization of targets and tools,” he said. “What’s more, the recent push toward MRI-compatible robotic systems will enable the use of interactively updated volumetric anatomical and functional imaging to guide surgical procedures.”

So what can we expect to see in the operating rooms of the future? It seems that our first ideas of autonomous robots performing surgical tasks may not be as far off as once imagined.

Mobile robots are being tested for basic patient aftercare, from delivering food and dispensing drugs to monitoring blood pressure and oxygenation. But automation in the operating theater may not be far behind.

“The technology already exists in industries like manufacturing and aeronautics,” Nguyen said. “It’s just getting those technologies into medicine. We’re working with a lot of new robotics companies and institutions like the Massachusetts Institute of Technology. It’s going to be sooner than we think – hopefully within my lifetime.”

Eventually, complex sets of orders could be programmed into one command, such as “Robot, go to liver,” and the robot automatically will position itself. Further intelligence could be built in specifying “no go” areas to prevent delicate organs from being hit accidentally.

We also can expect major advances in visualization. Much of today’s medical imaging is performed using ultrasound or radiation, but neither method works particularly well with live surgery. Ultrasound does not provide a clear enough image, and too much radiation is hazardous. MRI can provide interactively updated, very clear imaging of soft tissue, but it brings with it the additional challenge of compatibility with traditional surgical equipment.

Nguyen is working with several companies to find alternative light sources – such as fluorescence – to probe specific targets in the body for what he dubs “tailor-made surgery.” One aim is to track urine – typically obscured by layers of fat – as it travels within the body, an important step in bladder surgery.

Using fluorescent probes to pinpoint structures such as tumor cells and lymph nodes during live surgery also is in the cards. This will help surgeons excise just the part that contains the tumor cells, resulting in very precise and less radical surgery.