Musculoskeletal disorders are a common occupational hazard in Europe and North America and are among the most common reasons for long-term absences. Wearable technologies can reduce such injuries and loss of productivity and livelihood. One example is the Ironhand soft robotic glove from Bioservo Technologies AB.

Work-related upper-limb disorders annually cost €2.1 billion ($2.48 billion U.S.) across the EU and are responsible for 45% of all occupational diseases. Repetitive work is the greatest risk factor, and 74% of employees in Europe spend at least 25% of their working time performing repetitive arm or hand movements. Musculoskeletal disorders are the most common cause for limited capabilities on the job, severe disabilities, early retirement, and temporary incapacity to work, reported the German Federal Institute for Occupational Safety and Health (BAUA).

According to a survey performed by the European Agency for Health and Safety at Work (the equivalent of the U.S. Occupational Safety and Health Adminisration), 45% of those surveyed suffer from painful or fatiguing positions at work, 25% from back pain, and 20% from muscle pain. Studies show that half of all EU workers could be affected by musculoskeletal-related disorders by 2030.

Work-related disorders of the neck and upper extremities affect the throat, shoulders, arms, hands, wrists and fingers and can cause tingling, numbness, discomfort or pain. The use of vibrating tools or cold environments can worsen these problems. The effects include reduced mobility or grip strength, which can cause additional hazards, such as if an employee can no longer safely operate or even hold a tool.

Furthermore, demographic changes in the developed world mean that people are working and living longer. Improved ergonomics are increasingly important – both for healthy people as well as for those with disabilities. Industry is increasingly turning to systems that augment human capabilities, such as exoskeletons.

Workers get a better grip with Ironhand

Bioservo Technologies has designed Ironhand, which strengthens the human grip with help of the company’s patented SEM technology. The active gripping force support of the individual fingers is made possible with FAULHABER drives.

Normally, a gripping action is made possible by the muscles in the lower arm and hand. These muscles pull on tendons, thereby moving the fingers. Ironhand functions in a similar way: Pressure-sensitive sensors in the fingertips of the glove detect the gripping action that the user performs with his or her hand. A computer integrated in the wearable system calculates the additional gripping force that is necessary and small servomotors pull thin cables in the fingers. The higher the pressure on the sensors, the more power delivered by Ironhand.

The settings of the soft glove can be adapted according to personal preferences, as well as the type of work being performed. Data functions enable a digital risk assessment of the hand and the integration of the user in an Industry 4.0/factory-of-the-future concept. Grip-intensive applications with high ergonomic risk can be identified by analyzing the data during practical work, and users can take appropriate countermeasures.

Designed for versatility

The Ironhand glove is available in four different sizes and can be worn by left- and right-handed users, as well as both male and female users.

The battery pack, which is worn like a backpack, contains both a computer unit and the motors that control the individual fingers. Users can preset various profiles that contain different combinations of sensor sensitivity, force, finger symmetry and locking tendency. To change the profile, the user only needs to press a button on the remote control, which is located in the chest area.

For example, users can use the profile to flexibly respond to different requirements encountered during the course of a workday. A person may perform slightly stressful tasks in the morning, followed by activities during the afternoon that place heavy strain on muscles. Within milliseconds, Ironhand can provide up to 80 N of gripping force.

The system is designed to not interfere with personal protective equipment (PPE), such as gloves, fall-protection devices, helmets, or warning clothing. Users can put on Ironhand and take it off for breaks without external help. The capacity of the batteries in the power supply is designed for a typical workday.

DC micromotors provide power

To control the individual fingers, Bioservo uses DC micromotors with graphite commutation of the 1741 … CXR series in Ironhand. The series combines power, robustness, and control in a compact form, according to FAULHABER. This is ensured by graphite commutation, high-quality neodymium magnets, and the tried-and-tested winding of the rotor, said the company.

The powerful neodymium magnet gives the motors a high power density with a continuous torque ranging from 3.6 to 40 mNm. FAULHABER added that the CXR’s performance characteristics and compact size make it useful for a wide range of potential applications at an optimized price/performance ratio.

FAULHABER specializes in the development, production, and deployment of high-precision miniaturized drive systems, servo components, and drive electronics with up to 200 watts of output power. The company offers an extensive range of brushless motors, DC-micromotors, encoders, and motion controllers, as well as customer-specific systems. It said its systems reliably serve in complex and demanding applications, such as medical technology, factory automation, precision optics, telecommunications, aviation and aerospace, and robotics.

“We decided on the 1741 … CXR for the Ironhand because we have had very good experiences with FAULHABER drives in our products and have a long-standing cooperation with the drive specialist and its Swedish sales partner Compotech,” stataed Martin Remning Wahlstedt, development director at Bioservo.