Collaboration of three different fields from three different faculties of the University of West Bohemia in Pilsen (UWB) discovered new possibilities for manufacturing sockets for myoelectric hand prostheses.
The interdisciplinary international project Research Innovations in Prosthetics, which the Pilsen team implemented together with colleagues from Deggendorf Technical University, examined opportunities to use 3D printing in making hand prostheses and discovered new options in their design and technology.
“The manufacturing of a prosthetic hand is a complex technological process. The external socket of the prosthesis is usually made through lamination. Instead, we tried to use 3D printing, which allows for unlimited replicability and fairly simple adjustments to the design. It also makes it possible to pay much more attention to the aesthetics of the prosthesis while meeting functional requirements,” said Rita Firýtová from the Faculty of Health Care Studies (FHCS), the principal investigator of the project. The FHCS is the only faculty in the Czech Republic offering a full-time study programme in orthotics and prosthetics. Three Ph.D. students were invited to take part in the project.
The aim of the project, which also involved the Ladislav Sutnar Faculty of Design and Art and the Regional Technology Institute (RTI) at the Faculty of Mechanical Engineering, was to develop new methods for creating the shape, design and 3D printing models of sockets of myoelectric prostheses of the upper limb. The team of experts was testing various solutions with the help of Jiří from Pilsen, 55, who lost his right hand in an accident in 2001. “We have managed to develop a complete technological process and are actively looking for partners who would transfer the acquired know-how into application practice. In addition to technical elements, there is also the transfer of knowledge, based on our experience from interdisciplinary teamwork, which significantly helped us improve the innovation potential,” added Tomáš Chochole from the Ladislav Sutnar Faculty.
The author of the final design of the prosthesis is Zdeněk Veverka, head of the Product Design Studio at the Ladislav Sutnar Faculty, whose task was to utilise the space defined by the prosthetists on the one hand, and 3D printing experts from RTI on the other, as much as possible.
The strength of the 3D-printed prosthesis was a very nice surprise for the team members. “The 3D-printed prosthesis turned out to have very good mechanical properties and meets all the requirements,” said Tomáš Tykal from Protetika Plzeň, which also participated in the project.
And yet he claims that 3D printing is still a rarely used technology in prosthetics. “Some companies offer for example 3D-printed accessories that can be fitted onto a prosthesis. But this is purely for aesthetic purposes,” explained Tomáš Tykal.
Throughout the project, the Czech team was in contact with researchers from the Cham Technology Campus, which is part of Deggendorf Technical University. “This was a very close collaboration; particularly Zdeněk Chval’s team from RTI consulted the selected methodology and shared results of pressure, fatigue and other tests,” said Rita Firýtová from FHCS. The Bavarian team tested the designs in collaboration with Anna, 28, whose right hand was amputated due to a congenital deformity.
“Both teams reached similar conclusions,” said Rita Firýtová about the Czech and Bavarian parts of the project. “3D printing turned out to be a suitable method for designing a socket for a prosthesis. It can be assumed that future development will proceed in this direction,” she thinks. She believes that one of the benefits of 3D printing is the affordability of the prostheses. “So far, neither Czech nor German health insurance companies cover the costs of 3D-printed prostheses. But this may change over time,” she added.
“In any case, we will continue working on this topic. Jiří, who helped us test the prosthesis, has decided to start using it in his everyday life. This will help us see how it performs under heavier stress and compare this with the results of our laboratory tests,”
added Rita Firýtová.