A spin-off from the University of Ulm aims to help people whose hands are paralyzed due to an accident or illness regain some of their grip function with a novel orthopedic device. Dominik Hepp and Tobias Knobloch are developing the prototype of this customizable hand orthosis to the point where it’s ready for mass production. This year, the two medical technicians from Ulm, through their company HKK—founded in 2017— Bionics GmbH, which they founded in 2017, before the patented medical device “exomotion® hand one” is set to fill a gap in the market once it receives approval.
Intelligent Control via Muscle Signals
According to the founders, previous approaches have been limited to short-term use in a therapeutic setting and are hardly suitable for everyday use.
This battery-powered medical device was developed for adults with distal paralysis of the hand resulting from strokes or nerve injuries. The orthosis is not suitable for complete hemiplegia. This is because it uses sensors attached to muscles that are still intact on the corresponding side of the body; together with intelligent software, these sensors detect the wearer’s intended movement and use tiny actuators to assist the hand’s movement. The micro-actuators precisely transmit force to the actuation mechanisms, which open and close the fingers, thereby providing them with the necessary grip strength.
The hand orthosis consists of a supportive arm splint, the drive unit, a modularly adjustable finger exomechanism, a silicone glove, a sensor, and the control unit. This allows the range of motion of the fingers to be individually controlled; in other words, the orthosis can accommodate anatomical variations, such as limited finger joint mobility following prolonged paralysis. Additionally, individual fingers or multiple fingers can be flexed and extended independently of one another.
Exomechanics Instead of Electrical Stimulation
Unlike conventional models, the orthosis does not require electrical stimulation pulses, which is advantageous for a hand that is paralyzed but not necessarily numb. The new device developed in Ulm operates on an exomechanical principle, in which the fingers inside the glove are moved mechanically. It is therefore the glove that is worn over the paralyzed hand and activated by a sensor and control logic.
The hand orthosis can perform six different types of grips, including a closed fist, the so-called “credit card grip” (in which only the thumb moves), and the three-finger grip. The goal is to enable the paralyzed hand to perform everyday tasks again, whether it’s holding a bottle to open it with the other hand or carrying a laundry basket with both hands. The touchscreen display, which houses the control unit containing the orthosis’s power supply and logic, can be attached to clothing and folded open for easier operation. After use at the end of the day, the battery must be recharged.
The orthosis distinguishes between short and long muscle contractions. This allows it to generate control commands such as “Open,” “Close,” or “Change Grip.” This improves ease of use because it allows the hand to open and close, as well as switch back and forth between two grips, without using the touchscreen. The control technology is based on the principles of hand prosthetics. This is because, from a technological standpoint, the human-machine interface does not yet allow for live, simultaneous control of all fingers, explains engineer Dominik Hepp.
Craftsmanship and Industrial Manufacturing
The specialized exomechanics and the supportive arm splint, as used in the Ulm hand orthosis, can only be produced using 3D scanning and 3D printing. This has the advantage of combining the reproducibility and precision of industrial manufacturing methods with the traditional craftsmanship of orthopedic technology.
A customized medical device such as a bionic hand orthosis is assembled using a modular design. In medical supply stores with on-site orthopedic workshops, the orthopedic technician creates the glove based on a plaster cast (of the hand and forearm), which is fitted with varying numbers of these biocompatible exomechanical components. A 3D scan is then created, and based on this data, the brace is printed by a professional 3D printing service provider. The hand orthosis is assembled at medical supply stores that have the necessary technical expertise.
The medical device is initially set to be distributed in the DACH region through select medical supply stores. A robust and extensive network of doctors, therapists, medical supply stores, and patients has since been established. Over the course of the year, the usability and functionality of the medical device will be demonstrated in collaboration with patients. Doctors and clinics have already expressed interest in collaborating with the Ulm-based company.
A tool for everyday life
The hand orthosis is designed to help people with disabilities—ideally—reintegrate into daily life and the workforce. This requires that the hand orthosis be worn all day as an assistive device for daily living. The young entrepreneurs know that providing proof of this is important for obtaining reimbursement from insurers.
The company’s origins date back to 2011. At that time, student Dominik Hepp was exploring the idea of a hand prosthesis as part of a bachelor’s thesis project at Ulm University of Applied Sciences. The project grew in scope, providing material for additional theses, including one by Tobias Knobloch. The aspiring founders had meanwhile discovered a better—because relatively untapped—market for hand orthoses. After completing their studies and with the help of an EXIST startup grant starting in 2015, the technology was adapted from prosthetics to orthotics, the prototype was built, the business plan was developed, and its feasibility was demonstrated.
Meanwhile, the young company—which has expanded to include a business administration specialist and is backed by several investment firms—is increasingly making its presence felt in the public eye and has already achieved success there. Most recently, in 2018, at the renowned technology association VDE, where HKK Bionics was honored as one of two innovative startup teams shaping an electric and digital future. The winners from Ulm are now looking forward to a week-long trip to the technology mecca of Silicon Valley. The young entrepreneurs will surely bring back inspiration for successful business models from there to the city of Münster.
