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AJR April 2017

Daniel R. Swerdlow
Chief, Department of Medical Imaging Medstar Montgomery Medical Center
Associate Professor of Radiology
Georgetown University Hospital

Robotic Arm—Assisted Sonography: Review of Technical Developments and Potential Clinical Applications

While ultrasound imaging traditionally requires trained personnel, advances in robotics and data transmission create the possibility of telesonography. The review discussed in the questions that follow introduces clinicians to current technical work in and potential applications of this developing technology.

1. How did you become involved in this research?

Through Kevin Cleary, a coauthor and doctor of engineering who runs a lab at Children’s National Medical Center, Washington DC. Cleary received U.S. Army funding to build a prototype of a robotic arm that could perform ultrasounds, and asked me to serve as the radiologist-consultant on the team of engineers tasked with the project. The U.S. Army is studying these robotic systems as an alternative to placing skilled personnel in harm’s way on the battlefield. As a result of the project, I became familiar with the work of others in this field, so I wanted to review the research from the radiologist’s perspective as little has been written in the typical radiological literature.

2. What are some of the advantages of a robotic ultrasound arm system?

The robotic arm can be used when skilled personnel are not available to perform ultrasounds. For example, small clinics and hospitals, triage areas of diasters, battlefields, or remote locations typically lack trained personnel. Even when personnel are available, the robotic arm can be used independently to hold the probe still over the target during a procedure or to perform a task that is difficult or cumbersome for the sonographer.

3. What are the technical requirements of a robotic ultrasound arm system?

It must replicate the gross and fine motor control of the human upper extremity, and have a range of motion that would allow examination of all four quadrants of the abdomen. It also must have force limiters to avoid injuring a patient—this is called haptic feedback. The system should be capable of fine adjustments and hold still without drifting. Ideally, it would allow probe changes without human intervention.

4. Would a robotic ultrasound perform as well as an ultrasound performed by a human?

According to research, both approaches are effective, yet both have limitations. While medicine is probably decades away from wide implementation of such robotic arms, it is reasonable to assume that robots could enhance a radiologist’s or a technician’s ability to perform certain duties of the job. Robotic ultrasounds used in more typical clinical settings can reduce repetitive physical stress on sonographers.

5. What are the most important messages from the review?

Robotic systems have been designed for abdominal, obstetric, vascular intraoperative and interventional applications. Existing Internet and satellite links can transmit instructions to the device and return images to the master site in near real time. Many devices currently being used and under development are capable of generating the force, torque, and range of motion needed for typical ultrasound operations. Robotic systems have shown utility during interventional procedures, allowing complex planes and freeing hands from performing ultrasound.


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