Robotic System Aids CT-Guided Needle Biopsy

Lung biopsies and ablations are just some of the procedures that could become less complicated and more precise if a newly designed robotic system that aids in CT-guided percutaneous medical procedures earns FDA approval and makes its way into clinical practice.

Inventors of Robopsy (left to right) Nevan Hanumara, Alexander Slocum, Ph.D., Rajiv Gupta, M.D.,and Conor Walsh, pictured with the robotic system (forefront) that aids in CT-guided percutaneous procedures. Designed to sit over a patient's chest during a CT scan, the device grips, orients and inserts a biopsy needle or ablation probe while that patient remains inside the CT gantry. Photo courtesy of Stuart Garfield.

The robotic biopsy device, called Robopsy, has the potential to impact the healthcare industry far beyond lung procedures, said Rajiv Gupta, M.D., Ph.D., a radiologist at Massachusetts General Hospital (MGH) in Boston. Dr. Gupta has been collaborating on the project since 2004 with Conor Walsh and Nevan Hanumara, doctoral candidates at the Massachusetts Institute of Technology (MIT), and Alex Slocum, Ph.D., a professor in MIT's Department of Mechanical Engineering.

"Robopsy has the potential to change how a number of image-guided procedures are performed," said Dr. Gupta. "It can also open new ways to approach procedures that are currently performed through open surgery."

For example, with minor modification, the device could aid in the placement of ventricular drainage catheters in the head, said Dr. Gupta.

Designed to sit over a patient's chest during a CT scan, the device grips, orients and inserts a biopsy needle or ablation probe while that patient remains inside the CT gantry. The small, lightweight and disposable actuator can target lesions as small as 5 millimeters and significantly cut procedure times, saving the patient time under anesthesia and cost per procedure, said Dr. Gupta.

"Currently these are manual procedures that are performed in what are essentially blind steps," said Dr. Gupta. "It would be much easier if the probe could be placed under the command of the physician while imaging is under way. A real-time feedback loop is possible with a device like this."

MIT Students Create Prototype

A CT scan of the Robopsy prototype demonstrates minimal distortion to the images, which allows the needle to be clearly visualized. Image courtesy of Robopsy team.

This image of the Robopsy prototype shows the lightweight, patient-mounted device attached to the box housing electronics for controlling the motors. Photo courtesy of Robopsy team.

The device has been under development since Dr. Gupta made a presentation to Dr. Slocum's mechanical engineering class at MIT about five years ago. The class was held in conjunction with the Center for Integration of Medicine and Innovative Technology (CIMIT), a non-profit consortium of Boston teaching hospitals and engineering schools.

Intrigued by Dr. Gupta's presentation, students Walsh and Hanumara began creating a prototype for the device during the course.

"We thought that it sounded like a great problem we could work on," Hanumara said. "Three months later we decided to file the provisional application for a patent and we've been moving ahead with it ever since."

Hanumara and Walsh hope the device will eventually have many useful applications for radiologists.

"We tried to design the system to be as general as possible," said Walsh. "We initially focused on percutaneous needle insertions guided by CT, but they could potentially be guided by MR imaging or ultrasound as well."

Physicians Aid Design Process

Along with Dr. Gupta, the team has worked closely with physicians including Joanne Shepard, M.D., division chief of chest radiology at MGH, from whom they sought input on designing the device to better suit physicians' needs.

Although Robopsy was originally designed to be controlled with a joystick, designers discovered radiologists preferred using 2D scans and were more comfortable working off a computer screen.

"As one doctor said to us, 'I work in a 2D environment. My son might enjoy using a joystick like he does in a video game, but I don't want it,'" Hanumara said. "We got rid of that. We made that transition from thinking, 'Let's add all the cool engineering features' to 'Let's just include what the doctors need.'"

Another key was making sure the device actually aided doctors without hindering them in the process.

"It has to be fast," Walsh said. "Anything that slows a physician down at all is realistically not going to get adopted. The way our device works, all the doctor has to do is follow the same steps that are currently performed. They place the robot on the patient and once the device is scanned, we have software that semi-automatically figures out where the needle is and determines all the necessary equations. All the doctor is really left to do is just point and click."

The group also had to be careful in assuring doctors that the device is not intended to replace them, but to serve as a time-saving aid that also benefits patients by enabling earlier diagnoses and reducing the risk of complications through more precise probe placement.

At RSNA 2006, Hanumara and Dr. Gupta privately demonstrated the system to about 30 interventional radiologists—some who were resistant to the technology, fearing they would be replaced by a machine.

"That was a very small minority," Hanumara said. "The majority was favorably impressed by Robopsy's simplicity, size and functionality and expressed willingness to try it. Many suggested other soft tissue procedures where they could envision the device being useful."

Prototypes Prepared for FDA Approval

Despite the generally positive reception, Robopsy needs FDA approval before it can be marketed to the healthcare industry. As a step in that direction, the team has formed a manufacturing partnership to prepare the device for production. The prototypes that come from that process will be used in seeking FDA approval.

"The device is fairly close, but the process of bringing a device to the FDA is expensive," said Dr. Gupta, who added that further testing is also under way.

The team, which has raised $300,000 so far from CIMIT, the Department of Radiology at MGH and the Massachusetts Technology Transfer Center, estimates it will need $3 million to bring Robopsy to market.

"Our primary goal is to try to get this device out as quickly as possible so it can be used by physicians and assist patients," Walsh said.