Why Boston Dynamics Is Putting Legged Robots in Hospitals

For the past eight months, Boston Dynamics has been trying to find ways in which their friendly yellow quadruped, Spot, can provide some kind of useful response to COVID-19. The company has been working with researchers from MIT and Brigham and Women's Hospital in Massachusetts to use Spot as a telepresence-based extension for healthcare workers in suitable contexts, with the goal of minimizing exposure and preserving supplies of PPE.

For triaging sick patients, it's necessary to collect a variety of vital data, including body temperature, respiration rate, pulse rate, and oxygen saturation. Boston Dynamics has helped to develop a set of contactless monitoring systems for measuring vital signs and a tablet computer to enable face-to-face medical interviewing," all of which fits neatly on Spot's back. This system was recently tested in a medical tent for COVID-19 triage, which appeared to be a well constrained and very flat environment that left us wondering whether a legged platform like Spot was really necessary in this particular application. What makes Spot unique (and relatively complex and expensive) is its ability to navigate around complex environments in an agile manner. But in a tent in a hospital parking lot, are you really getting your US $75k worth out of those legs, or would a wheeled platform do almost as well while being significantly simpler and more affordable?

As it turns out, we weren't the only ones who wondered whether Spot is really the best platform for this application. We had the same response when we started getting pitched these opportunities in Feb / March," Michael Perry, Boston Dynamics' VP of business development commented on Twitter. As triage tents started popping up in late March, though, there wasn't confidence wheeled robots would be able to handle arbitrary triage environments (parking lots, lawns, etc)."

To better understand Spot's value in this role, we sent Boston Dynamics a few questions about their approach to healthcare robots.

This video shows Dr. Spot (their nickname, not ours) walking around Brigham and Women's Hospital.

While the video is very focused on Spot itself, the researchers also released a paper about the effectiveness of Spot's payload, and about how well it worked in the triage tent, which was outside of the hospital and looks like this:

Photo: MIT/Brigham and Women's Hospital/Boston Dynamics

The COVID-19 triage area at Brigham and Women's Hospital includes a medical tent outside of the emergency department (a), where the researchers deployed a Spot with IR camera for fever screening and respiratory rate detection (b).

To me, this seems like somewhere a wheeled robot would do just fine, although Boston Dynamics told us that the tent also had concrete bumps and curbs that made mobility a challenge." Spot left the tent and wandered around the hospital when the small number of hospital staff that had been trained to operate the robot rotated to the emergency department instead. It turns out that there's a second, separate paper in the works about the effectiveness of Spot for telemedicine that's still under peer review, but it'll more directly address how useful Spot itself is as a platform in a busy hospital.

But back to our question of how useful a legged robot like Spot is in a well-constrained and mostly flat environment like the triage tent-concrete bumps and curbs could certainly be a challenge, but it seems like minor alterations to the environment (say, adding some ramps or something) would be much more cost effective than picking a legged robot over a wheeled robot. Even if there are obstacles (like stairs) that are difficult for a wheeled robot, using two (or more?) wheeled robots instead of one legged robot could still potentially be a more efficient solution.

Photo: MIT/Brigham and Women's Hospital/Boston Dynamics

The researchers mounted four cameras on Spot and showed that they can measure skin temperature, breathing rate, pulse rate, and blood oxygen saturation in healthy patients, from a distance of 2 meters.

For that matter, why use a robot when you could just make your remote monitoring system stationary, instead? That was our first question for Boston Dynamics roboticist Marco da Silva and field applications lead Seth Davis.

IEEE Spectrum: From what I understand from the paper, the goal was to develop a system that can adapt its distance and angle of view to take more accurate readings of patients, rather than asking patients to adapt to a static system. Why make this a mobile robot at all, rather than (for example) something that sits on a table with a couple of actuated DoFs that make the necessary adjustments?

Marco da Silva: It's possible that you could build an actuated device expressly for this purpose but Spot already existed and was ready to be deployed. Further, the Brigham and Women's team was expecting long lines of patients at intake or patients seated in the tent. The expectation was that Spot could efficiently move from patient to patient.

Your Boston Dynamics colleague Michael Perry mentioned that there wasn't confidence wheeled robots would be able to handle arbitrary triage environments (parking lots, lawns, etc.)." Can you elaborate on that?

Seth Davis: We initially questioned the need for legged robots or even a mobile platform. In this case, the Brigham and Women's and MIT teams informed us that a wheeled robot with sufficient payload capacity was not readily available and not well suited to the initial concept which was to operate outside the hospital in temporary treatment areas. In addition to its mobility, our robots' obstacle avoidance abilities and simple user interface also seemed appealing to the Brigham and Women's team as they worked right out of the box and did not require additional development or significant training in order to get something their staff could use.

In addition to its mobility, our robots' obstacle avoidance abilities and simple user interface also seemed appealing to the Brigham and Women's team as they worked right out of the box and did not require additional development or significant training in order to get something their staff could use." -Seth Davis, Boston Dynamics

With the experience that you have now, do you think that legged robots are worth the extra cost and complexity in these situations, relative to a (likely much less expensive) wheeled platform?

Davis: It depends on the environment, the requirements for speed of deployment, and how flexible the solution needs to be. It's highly likely that the pandemic is going to have researchers looking at creating one robotic solution (fixed or mobile) to interact with patients. In this instance, the rapidly evolving pandemic situation necessitated a robot that could be deployed in a tent, a parking lot, a lawn, or in the Emergency Department, and rapidly adapt to the sensor and data collection needs of their team.

Has this experience suggested any other healthcare applications where legged robots would be uniquely useful?

Da Silva: We have a few hospitals around the world that are interested in this specific configuration of Spot as a just in case" solution if or when their triage facilities need to be set up in an unknown environment. Moving forward we have teams that are looking at delivering goods and doing rounds in convalescent facilities, and mobile disinfection in ad hoc or unstructured environments. One thing we learned as well is that elevator usage is often over capacity in hospitals causing long wait times, so we've been approached to see how Spot can carry physical items up and down the stairs to alleviate elevator congestion.