Standardization News

The Promise of Exoskeletons

Better, stronger, faster. We have the technology, but do we have the standards?
Jack Maxwell

The idea of a mechanical suit that a person could put on to enhance strength or speed or jumping ability has been a staple of science fiction for decades. And though a number of such devices were designed over the years – with fanciful names like the pedomotor, the pedipulator, and even the “man amplifier” – none came to fruition.

Until Hardiman.

Hardiman – the earliest modern example of a powered exoskeleton – was the result of a collaboration between General Electric and the U.S. military in the 1960s. Hardiman could enhance the strength of the wearer by a factor of 25.

Unfortunately, the apparatus never advanced beyond the prototype stage due to issues with weight, stability, and power supply.

Fast forward to 2017, however, and you’ll see that many of those challenges have been overcome. The exoskeleton industry has dramatically matured, with dozens of companies using cutting-edge materials and technologies to launch viable products that leave Hardiman in the dust. 

Some exoskeletons help workers maneuver heavy tools. Others give stroke victims greater mobility. Still others have military applications. It’s an exciting time to be involved in this industry.

As is often the case with new innovations, the development of standards (to measure performance, to evaluate safety, etc.) needs to keep pace with the stunning technical advances in labs and workshops. Even something as basic as terminology – What exactly is an “exoskeleton”? – needs to be considered in order to drive these exciting new products toward full acceptance in the marketplace.

Answering the Call for Standards

ASTM International’s new committee on exoskeletons and exosuits (F48) will work to address this standards vacuum. The group was formed in September at a meeting held at the organization’s global headquarters, attended by dozens of representatives from industry, trade associations, and government agencies. This included experts from Australia, Japan, the United Kingdom, and the United States.

At that meeting, they decided to initially focus on five areas, with separate subcommittees for each:

  • Design and manufacturing
  • Human factors and ergonomics
  • Task performance and environmental considerations
  • Maintenance and disposal; and
  • Security and information technology

Based on the committee's first meeting, it was clear that the industry had already reached consensus on what exoskeletons and exosuits are not.

They are not robots. Webster’s dictionary defines a robot as both “a machine that looks like a human being and performs various complex tasks (such as walking and talking) of a human being” and “a device that often performs complex and repetitive tasks.”

Robots operate autonomously. An exoskeleton, on the other hand, is a machine that a man or woman essentially puts on.

“An exoskeleton is a wearable system,” says Roger Bostelman, advanced mobility systems engineer at the U.S. National Institute of Standards and Technology. “It basically can be powered or unpowered, tethered to a wall for working in a room, or untethered for free mobility. They’re able to be strapped on very quickly, donned and doffed, and basically used for whatever the task is at hand.”

It’s the word “task” in that quote that speaks to the incredible potential of exoskeletons and exosuits.

Picture this:

  • A soldier carrying a heavy pack on a long mission — an exoskeleton could help her go farther and faster, with less fatigue;
  • A construction worker using a heavy rivet gun all day — an exoskeleton could help him work more efficiently, with no late-day drop-off as his arms begin to tire;
  • Or, perhaps most poignantly, a stroke victim learning to walk again — an exoskeleton could help her retrain muscles that have atrophied by enabling her to do more repetitions during rehab sessions.

These examples illustrate the three burgeoning segments of the exoskeleton market: military, industrial, and medical. (Recreational use is considered a more distant prospect, though it’s hard not to get excited about the idea of putting on your exosuit to do a quick 50-mile run before breakfast.)

A popular industry website ( lists nearly 60 companies, businesses, and startups directly involved in building exoskeletons and related devices.

The list includes a few familiar names like Hyundai, Lockheed Martin, and Panasonic, but most are relatively new and young. The products they make range from the SEM glove, a soft device for people who have difficulty gripping objects (Bioservo Technologies AB, Sweden), to the ATLAS powered lower-back skeleton, which relieves pressure on the spine (Japet, France), to an upper limb exoskeleton, a 3D-printed arm-and-wrist unit designed to suppress tremors (MedEXO Robotics, Hong Kong).

Clearly, exoskeletons and related technologies take many different forms. But all are designed to achieve one fundamental goal: helping humans realize or enhance their potential.

The Standards Gap

As the companies mentioned hire and expand, a growing challenge facing the exoskeleton and exosuit industry is lack of standards. Individual companies have created their own testing protocols as a matter of necessity, but the formation of the new committee – formally approved Oct. 16 by the organization’s board – marks the beginning of a broadly inclusive process that will develop industry-wide standards for design, performance, and safety.

“I think it’s important to have standards for at least two reasons,” says Maury Nussbaum, Ph.D., a professor in the department of industrial and systems engineering at Virginia Tech, Blacksburg, Virginia.

“The first is that there’s not a lot of formal research out there on the effectiveness of these types of devices. People are developing their own testing protocols, their own testing methods. It would be ideal if there were some consensus on how to evaluate these devices so that results can be compared across groups,” he says.  “The second is that eventually standards will allow for some consensus on evaluating the potential benefits, or limitations, of these devices.”

Russ Angold, president of EksoWorks (the industrial division of Ekso Bionics, Richmond, California,), notes that standards will also increase the pace of innovation. “Having published standards, or the ‘rules of the road,’ will allow us as an industry to innovate faster by having consistent specifications to design to, while at the same time providing confidence to the end users, who will know that they are getting exoskeleton products that are safe, reliable and perform as advertised.”

Donald Peterson, Ph.D., chairman of the new committee, and dean of the College of Engineering and Engineering Technology and professor of mechanical engineering at Northern Illinois University, agrees with Angold’s assessment. “Standards will allow exoskeleton and exosuit companies to enjoy both short- and long-term cost benefits, particularly through access to intellectual property and technologies for use in product research and development,” he says. “I believe the infrastructure that will be established from these consensus industry standards will make innovation feasible and lead to continuous ingenuity, entrepreneurship, and domestic and global competition.”

“Standards are going to be key to communicate,” adds William Billotte, Ph.D., manager of the National Security Standards program at NIST. “There’s a lot of terminology out there, and when people say a word it means many different things to many different people. That’s the first thing that standards are really going to help us with: creating a common language for exoskeletons.”

Here’s one example. The acronym HMI stands for human machine interface. But, as Angold points out, “You have to define what HMI is. Is it a graphical interface, or an interface that the physical therapist is using to input the settings into the device, or is it the actual part of the exoskeleton that’s touching the human?”

The new committee plans to address the standardization of terminology as one of its first actions. Reaching consensus on a defined set of terms could help lay the groundwork for more complex technical discussions that lie ahead.

Fortunately, a number of well-established ASTM International committees are doing strong work in related areas that F48 may be able to draw upon. These include medical and surgical materials and devices (F04), personal protective equipment (F23), homeland security (E54), driverless automatic vehicles (F45), and additive manufacturing technologies (F42), which is responsible for standards relevant to making exoskeletons and exosuits, and is developing standards for AM used for medical devices.

Many of those who attended the organizational meeting expressed excitement to learn that the global experts on existing committees had already created some of the technical foundation to support exoskeleton and exosuit standards.

The Promise of Exoskeletons

Notably, the attendee makeup of the organizational meeting for the new committee reflected the fact that medical uses of exoskeletons represent the largest segment of this emerging industry. (More than half of attendees had a primary interest in medical applications.)

Ekso Bionics is one of the more active companies in this segment. “We have hundreds of devices being used at customer sites, primarily in North America and Europe, on the medical side,” says Angold.

According to Angold, the company created the first exoskeleton cleared by the FDA for stroke and spinal cord rehabilitation. It’s designed to help patients get back on their feet by helping them relearn correct step patterns and weight distribution. It also allows real-time settings adjustment as well as software customization to adapt to the patient’s needs.

Interestingly, the company tracks data generated by its devices in use around the world; at the time of this writing, the number of steps taken by people using them topped 80 million.

Ultimately, the lines between various applications of exoskeletons and exosuits could easily blur. For example, one variation on an exosuit could help prevent workplace injuries while another variation could help a worker recover. Also, a nursing home employee could maneuver a heavy patient with the help of an exoskeleton device, ensuring that both the worker and the patient are safe.

“At the end of the day, the look on that construction worker’s face when you make his job that much easier is very similar to that stroke patient who is up and walking again,” Angold notes.

Indeed, overall quality of life – at the most fundamental level – may be where the promise of exoskeletons is most compelling.

From children born with significant disabilities… to military responders to a natural disaster… to aging construction workers who want to keep working… exoskeletons and exosuits – and the standards that support them – will help us all perform at our highest level throughout our lives.

Photo courtesy of BMW Group, Plant Spartanburg

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