Every minute a hospital worker spends delivering bed linens or pushing a medicine cart means time away from patient care. Automating these mundane tasks frees up medical staff for more important duties, and that's just what one company is doing with its hospital service robots. Aethon Inc., Pittsburgh, Pa., has developed the TUG robotic indoor transport system, an automated courier that can deliver and track instruments, medications, meals, and lab specimens anywhere in a facility. Sophisticated microprocessors, along with infrared and ultrasonic sensors called “light whiskers,” are at the heart of the robot's intelligence, while its muscle comes from battery-powered gearmotors.

Design dilemmas

Navigating a bustling hospital environment is difficult enough for a person pushing a delivery cart, and exceedingly more complex for a robot. Add in the ability to enter an elevator, go to the right floor, find the nursing station that ordered a particular medication, and deliver it on time. Years of development went into creating the decision-making capability within software, designing the complicated sensor array, and enhancing communication capabilities so that the TUG always knows where it is and where it's going. A touchscreen interface helps workers communicate with the robot and tell it what to do. The design team had to confront system compatibility issues with other wireless communication networks, as well as resistance from hospital workers wondering whether robots may be taking their jobs.

Back story

Robot entrepreneur Henry Thorne founded Aethon in 2001. A graduate of the Robotics Institute of Carnegie Mellon University, Thorne worked at General Motors for five years engineering robotic systems including one of the largest robotic arc welding assembly lines ever created. In 1990, Thorne founded Cycle Time Corp. where he created the first graphical user interface for industrial robots, a technology now used on more than 5,000 robots within automotive manufacturing. In 1995, Thorne began working on mobile robots and created the first personal robot — CYE — originally sold by Probotics Inc. He founded Aethon in 2001 to commercialize bigger and brighter robots. The TUG was inspired by tugboats and their “trailer hitch” interface, according to Thorne. TUGs are actually base robots that can be attached to various delivery carts.

Design impact

TUG robots are now employed in more than 100 hospitals delivering supplies, meals, and medications. The price tag is $105,000 for purchase or $1,500 per month for a lease. TUGs could also be used to track and recover hospital equipment using RFID technology, perform security patrols, and transport medical waste. In the future, they might be found delivering hotel room service or distributing merchandise within warehouses.

For more information, visit www.aethon.com.

How TUG travels

Before a TUG system is installed in a hospital, Aethon engineers map the landscape corresponding to the areas that the robot will travel and designate a “home base,” such as a pharmacy. Navigation software absorbs and accommodates the facility's layout.

Computer - The onboard computer uses its detailed hospital map and navigation software to plan routes, avoid obstacles, and track its own location.

Batteries - Four lead acid batteries provide six hours of operation, fully charging in four hours or less.

Motors - Two independent dc motors control wheel movements.

Light whiskers - Infrared and ultrasonic “whiskers” detect objects such as IV poles and people in TUG's path. Upon sensing an obstacle, the robot stops. It then announces, “Waiting to proceed,” and maneuvers around the object.