For several years, technology based on robotic exoskeletons – structures that support and enhance the physical abilities of human beings who wear them – has found numerous and growing applications both in the biomedical field, for the rehabilitation of patients, and in that of manual labor, as a means to reduce loads and improve safety. The automotive industry is among those that have so far hinted at greater prospects for collaboration with companies specializing in the production of exoskeletons. But other possible uses and in some cases already adopted exist in construction or even in agriculture, and in general in the works of the manufacturing industry that involve repetitive and tiring steps for the staff employed.
The production of industrial exoskeletons is mainly of two types: that of “active” systems and that of “passive” systems. The type most often referred to when talking about exoskeletons is the “active” one, in which the thrust is produced thanks to a battery or a different propulsion system. But recent research has also focused on “passive” models, which do not provide direct energy but exploit advances in materials science to build robust and lightweight exoskeletons capable of supporting and facilitating the movements of humans.
Applications in the medical field
Recent significant growth is that involving applications in the medical field, where exoskeletons are used to restore functions in people with disabilities and to help patients with walking difficulties. It is a market that is still affected by high costs and therefore mainly supported by hospitals and rehabilitation centers. But the gradual decrease in those costs is slowly favoring the expansion of the supply of consumer products for the population, which could further absorb research and development costs. According to a forecast by the research company Technavio, the market for exoskeletons used in the medical field should grow by about 290 million euros in the four-year period 2020-2024. For some years now, the progress made in the field of wearable models has been allowing thousands of people to more easily deal with the consequences of spinal injuries, strokes and neurological problems.
Larry Jasinski is the CEO of ReWalk, one of the most active and well-known US companies in the production of robotic medical devices for people with lower limb disabilities. According to data reported by Jasinski there are about 30,000 people waiting to receive an exoskeleton and about 18,000 each year request it. One of the reasons that have increased companies' investments in research has been the gradual increase in approvals of these devices by the authorities.
In 2019 ReWalk received from the Food and Drug Administration (FDA) – the US government agency that deals, among other things, with the regulation of medical equipment – the authorization to sell its model of exoskeleton to rehabilitation centers (ReStore Soft Exo-Suit) intended primarily for patients with hemiparesis due to stroke. It costs around 24,000 euros and is a kind of tibial band connected by mechanical cables to a pouch that operates a hydraulic system. It is used to assist walking by facilitating the flexion of the foot and facilitating its lifting from the ground. The idea of the biomedical engineers who designed the device, supported by a series of specific studies, is that by promoting correct patient walking, the brain can learn again and restore more quickly the function lost after the stroke.
Another very popular ReWalk device, approved by the FDA and known for the longest time in the market, is a home use exoskeleton (ReWalk Personal 6.0) designed primarily for patients with paraplegia due to spinal injuries. It costs between 56 thousand and 70 thousand euros, depending on the customization of the project. It is a system powered by a transportable battery and controlled by a wristwatch that detects movements via sensors positioned at the height of the belt, in order to direct the walk according to the inclination of the bust detected.
California-based Ekso Bionics is another American company famous for manufacturing exoskeletons in the medical field. One of its most used models, the EksoNR, performs a similar function to that of ReWalk's ReStore – it is developed for patients with walking difficulties due to stroke or spinal injuries – and is intended for use only in a clinical setting and in health centers. rehabilitation. The facilities that use Ekso equipment all over the world are over 270, of which eight are in Italy.
In Japan too, research has produced significant results in recent years, and one of the possible reasons for the substantial investments in this sector is that it is in the country's interest to try to keep the growing younger part in the world of work for as long as possible and without accidents. of the population.
HAL (Hybrid Assistive Limb) is the most ambitious and versatile project of the Japanese company Cyberdyne, developed in collaboration with the University of Tsukuba, in the prefecture of Ibaraki. It has already produced several models of exoskeleton, all in constant updating: they share the same technology but are distinguished by the type of support offered to the user (arms, legs, torso or all limbs). It works by using electromyographic signals detected through a series of electrodes attached to the skin and connected to a processor. Depending on the signals received, i.e. based on the user's intentions, the system moves the joints of the exoskeleton in order to support, support and amplify the movement.
In addition to rehabilitation, HAL can also be used to facilitate the performance of heavy work. In 2012 Cyberdyne designed some special versions for decontamination works in the areas around the Fukushima nuclear power plant.
Other applications in work
In recent years in particular, a progressive introduction of exoskeletons in some sectors of work in Japan has been partly conceived as a measure to try to offset the effects of demographic trends on employment. According to data released in 2018 by the Ministry of Internal Affairs and Communications, 28.4 percent of the Japanese population (35.88 million) is 65 or older. And this band represents about 12.9 percent of the country's workforce. The government recently presented a series of bills designed to raise the retirement age by inducing companies to propose incentives for employees who work until they reach the age of 70.
The use of particular “active” exoskeletons to be worn as backpacks, developed to increase the strength and endurance of the operator who uses them, would allow many Japanese older workers to remain active longer doing relatively strenuous jobs previously assigned to people younger. The suits, designed by the Innophys company and sold at a price of around 7,000 euros each, weigh just under 5 kilograms. Through a compressed air mechanism that accompanies the autonomous rotations of the torso, they allow you to lift weights up to 25 kilograms more easily. Unlike other models used in rehabilitation – which in many cases require the rigidity necessary to support people who would not stand on their own – the Innophys exoskeletons used in the work are made of soft materials. In the first quarter of 2020 the company sold 10,000 units.
The prospects of a future massive use of exoskeletons at work by the older working population is considered reassuring in some respects, to the extent that these devices can serve to avoid injuries. But on the other hand, they raise a series of questions relating to the appropriateness of making older people work longer and to the risk of a “normalization” of exploitative practices in social policies. According to Rory O'Neill, chief editor of the award-winning British workplace safety magazine Hazards magazine, the introduction of exoskeletons into the labor market should be preceded by stricter regulations. “It should be remembered that throughout the history behind the solutions imposed by the bosses to increase safety at work, there was then discovered a primary desire to increase production”, warned O'Neill.
Also in the rest of the world and in the United States in particular, active exoskeletons have for some time been a research area of interest for the automotive industry and production with assembly lines. Advances in the science and technology of polymers and other materials are also behind the recent development of less complex and less expensive exoskeletons, including one manufactured by Archelis, a Yokohama-based startup, and unveiled at the virtual edition of CES 2021 ( the great technology fair held every year in Las Vegas).
The strength and lightness of the materials used allowed Archelis to produce a promising model (ArchelisFX) designed to relieve the loads on the joints of the lower limbs when lifting heavy objects. But it is also meant for people who have to stand for prolonged periods of time or for those who have recently undergone surgery. The cost estimated by the company for ArchelisFX should be around 4 thousand euros.
According to recent research conducted by the University of Tampere and the Lappeenranta University of Technology Campus in Finland, the stable use of wearable exoskeletons could also serve to improve ergonomics and increase the strength of geriatric care staff. One of the points highlighted by the researchers is that these technologies – mainly used in production, logistics and rehabilitation – should be more present in sectors with a high concentration of workers and especially female workers suffering from musculoskeletal disorders due to overload.
Similar research is also carried out at the Vrije Universiteit Brussel, in Belgium. “We don't want people to work faster or harder,” said Sander De Bock, a PhD student in exoskeletal research. “We want to reduce absenteeism by making exoskeletons reduce sustained strain and improve conditions. of work”. Future studies, according to Jean Theurel, researcher at the French National Research Institute for Health and Safety at Work (INRS), will have to focus on the long-term – still unavoidably unclear – effects of prolonged use of these devices on joints and on other parts of the body involved in the assisted movements.
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The research around exoskeletons could in the future also involve companies interested in less specific applications and aimed at a very wide audience. The Nike apparel company recently co-funded a Stanford University research that produced a prototype robotic exoskeleton for the ankles. According to the first results shared by the researchers who measured it, the efficiency of the device should allow runners to save 14 percent energy compared to running in normal sports shoes without an exoskeleton. “We thought these exoskeletons of ours could make it easier and more fun to run, and get people to do it more often,” said Steve Collins, one of the mechanical engineers involved in the development of the device.
And supersoldiers?
For a long time, technological research on exoskeletons has been directed towards possible military uses, mostly producing experiments without follow-up. This condition, combined with the reflections of a long, first literary and then successful cinematographic narrative, has helped to strengthen in the common opinion the link between the idea of exoskeletons and that of “super soldiers” (if only in the de inclination that does not involve the modification of genes). But the boundaries between research focused on medical applications and that in the military are not stable and defined, and are often ethical in nature.
According to Patrick Lin, professor of philosophy at California Polytechnic State University and director of the research group Ethics + Emerging Sciences Group, “almost everything in this area lends itself to dual use.” “Therapeutic use can easily be converted to military use, and it's not that easy to find ways to prevent that from happening without resorting to too broad regulation that would also hinder therapeutic research,” Lin told the BBC. It is rather a distinction made a posteriori: in practice the two lines of research often proceed in parallel.
Ekso Bionics worked extensively with the US military before expanding its exoskeletal offering to suit a wider audience. One of the first models produced for the army, a hydraulically operated 'active' exoskeleton (HULC), was designed to help soldiers in war zones carry loads of up to 90 kilograms at maximum speed. of 16 kilometers per hour.
In 2018, military-based aerospace engineering firm Lockheed Martin obtained a $ 6.9 million (approximately € 5.6 million) grant from the US government to deploy and adapt an exoskeleton model originally developed by the US government. Canadian medical technology company B-Temia for assisting people with mobility difficulties.
It is a wearable exoskeleton (called ONYX) that uses a sensor system and other battery-powered technologies to provide support for the body's natural movements. The objective in this type of research is basically to develop systems capable of reducing the efforts of soldiers in the transport of normal military equipment, which between bulletproof vests, radios and night vision goggles can reach a total weight of 64 kilograms. The same reasons could make these systems also useful for public rescue departments such as firefighters, to facilitate their operations in emergency situations.
Previously, other very ambitious US Army programs with exoskeletons, such as the Tactical Assault Light Operator Suit (Talos), had been progressively shelved or split into programs with more realistic objectives. “Basically I'm here to announce that we are building Iron Man,” President Barack Obama said jokingly in 2014 as he presented a series of innovation plans for the manufacturing industry resulting from the collaboration between various companies and research institutes.
A major challenge in developing exoskeletons for use in the military, according to Vikram Mittal, professor in the systems engineering department at West Point Military Academy (USMA), has always been reaction times. Without instantaneous detection of the operator's intentions – currently still difficult to obtain – the delay between intention and movement gives the operator “the sensation of moving in a pool of jelly,” writes Mittal. Another technical difficulty is linked to the current limitation of the movements of the joints of the exoskeletons, which ends up determining a reduction in general agility. And then there is the whole problematic part relating to energy. For the type of power required, too noisy engines, too hot fuel cells or too heavy batteries would be needed, without considering all the safety risks.
Even if all these technical problems were resolved one day, Mittal continues, military exoskeletons would likely produce more disadvantages than advantages. Equipping entire military corps with efficient and customized exoskeletons would probably cost exorbitant. And in the event of a battle, enemies would easily find ways to exploit vulnerabilities in equipment. The suit could also be built to withstand explosions and falls, but the sudden acceleration and deceleration would kill the operator inside. “The logical approach would be to take the human out of the suit, which in turn eliminates the need for an exoskeleton,” concludes Mittal.
