The continued rise of 3D printing is having a big impact on the medical world, with scientists using the manufacturing technique to create everything from spine cages to an upper jaw prosthesis for a cancer patient. Now, in Poland, it's been used to create an extremely specialized device – a hand-worn orthosis built specifically for one particular patient.

The new project focused on creating a rehabilitation orthosis to help patients with mild paresis. The wearable device needed to be light and comfortable, so as to avoid damaging the weakened appendage to which it's attached, in this case the patient's hand.

The project was led by Wroclaw University of Technology's Eliza Wrobel, who was asked for help by a 33 year-old man whose partially-paralyzed hand meant that he was unable to hold dumbbells to exercise, or grip a table tennis paddle to play his favorite sport.

The researchers set about tackling the problem by making a plaster cast of the patient's right hand, and then using it to create a detailed 3D model. The model was then used as a guide when using CAD software to design a mechanical solution that would directly assess the patient's needs.

The largest part of the device – referred to as the husk – was designed to fit closely around the wrist of the patient, while smaller parts were conceived to support the fingers, imitating the structure of the joints. A series of lever mechanisms connect the different parts of the device, with a single lever on the back of the hand allowing the orthosis to help the user to grip objects.

The design is made up of more than 70 different parts, and was manufactured on a Zmorph hybrid 3D printer using ABS filaments of different colors. The vast majority of parts were made using the 3D printer, including the small pins used to connect the lever system.

According to the researchers, the orthosis is strong enough for the patient to use during physical activities. In the future, the team hopes that such custom-made 3D printed rehabilitation orthosis could become widely used, significantly improving the day-to-day life of patients.

Source: ZMorph

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