Student Project Competition: Assistive Devices and 3D PrintingFollow project
Who are we?
We are a team of Glasgow University students driven to producing assistive devices for people in need. This effort not only progresses our key skills in biomedical design and project management but grants us with a fantastic opportunity to harness the skills, resilience and mindset of young engineers to change the lives of others for the better. We are part of the Outreach Division in Handprints e-NABLE Scotland; a non-profit, student-led society that 3D prints prosthetic hands and furthers innovation in the 3D printing biomedical world.
Our team consists of Rebecca and Zarina who are biomedical engineering students and Meda who is a product design engineering student, all fully equipped with essential CAD design skills and determination to produce our innovative assistive devices. Leo and Saoirse are medical students who aid with discerning clinical specifications and applications of the devices. Special recognition has to be given to the Queen Elizabeth National Spinal Injuries Unit for their guidance and continuing support throughout the project.
The assistive devices we have developed are catered to recipients that are affected by blindness, or who have experienced traumatic or non-progressive spinal cord injuries. Our aim is to facilitate function and improve the quality of life for recipients. This project will focus on three devices that we have produced. Our “Braille Tiles” are used to help young children learn braille in a novel and creative way. The universal Tool Holder allows anyone who has limited use of their arm to hold everyday objects such as cutlery or a toothbrush. The Hanoi Tower we have designed is a device made for the rehabilitation and refinement of arm movement after a spinal cord injury.
During the progression of these projects, we have sensed the phenomenal potential of our 3D printed assistive device design efforts and as a result, are driven to share our inspiring efforts and future visions with the Design Spark engineering community!
Introduction to Spinal Injuries and Visual Impairment
Spinal cord injury is defined as damage via trauma or disease, to any part of the spinal cord or nerves which can cause loss of muscle and sensory functions. (1) The clinical presentation varies depending on the site and degree of injury. The higher the spinal cord injury occurs, the worse the resulting paralysis will be. This may result in complete or partial loss of motor and sensory function below the site of injury. (1) Current treatment guidelines include surgical interventions to reduce or regress the progression of symptoms and rehabilitation through physical and occupational therapy. This includes strength and dexterity training in order to retain and retrain movements as well as to prevent muscle wasting. (2)
In general, someone is legally blind if they have 20/200 vision or worse. This describes someone who can see an object from 20 feet, where an average person would see it at 200 feet. Vision impairment is defined as someone with 20/40 vision or worse, i.e. they can see an object clearly at 20 feet where an average person could see it from 40 feet away. (3) Blindness and visual impairment in children can result in delayed motor, language, emotional, social and cognitive development. This can have lifelong consequences. They might also have troubles in school and experience lower levels of educational achievements. (4) To make learning for children with visual impairment easier, visual materials used in classrooms should be properly adapted. Some of the most common adaptations are auditory input, assistive visual devices, and material that can be understood via tactile and kinaesthetic senses. (5) One example of this is Braille.
Our primary motivation is to help people using our 3D printing skills. This can include facilitating basic functions that most people might take for granted. For example, learning how to read, or holding a knife and fork. These small changes can have a huge impact on quality of life. Individuals with spinal cord injuries often have a significant loss of independence. We have targeted our spinal injury devices for two purposes; to facilitate and support functions that were previously lost due to injury, and to train fine motor skills in order to promote independent movement and enhanced life progression.
Handprints is a voluntary run organisation and we place a huge amount of importance on providing our products and services free of charge. Not only does this benefit our recipients but this also extends to our National Health Service. Healthcare professionals are best placed to advise on what the needs of their patients are. Our biomedical engineering skills can be used to develop the devices to meet these needs, and help patients and NHS staff. The aim of our Braille Learning project was to create a Braille learning tool that is widely accessible, easy and cheap to print, and provides a fun and engaging way to learn Braille. During the initial research for our project, we found that many Braille learning materials can be too expensive for Primary schools to purchase. Therefore, we were inspired to design 3D printed Braille tiles that are durable and can be donated free of charge by Handprints to as many schools as possible. We believe that making learning aids for Braille as accessible as possible would allow children with visual impairment to learn Braille from an early age and therefore make the learning process simpler and more intuitive.
Handprints e-NABLE Scotland is an organisation that 3D prints upper limb prosthetics for people who need them. The purpose of the Outreach Division of Handprints is to reach out to other fields and propose solutions by applying our 3D printing skills and knowledge. 3D printed solutions offer a great creative opportunity. We attempt to provide for recipients who need a novel and individualised approach. Part of our motivation is innovation and creativity in the 3D printing field and the furthering of its applications in a wider range of industries. This also serves to bring people from different fields to work together toward their common goals.
Assistive Devices + Design Journey
1. Universal Tool Holder
The universal Tool Holder is a device for someone who has limited use of their hand and/or arm. Where an individual has lost the ability to grip an object, the tool holder is designed to assist with this. For example, holding a toothbrush, cutlery or hairbrush. We printed 3 sizes of tool holder, incorporating a modular design to cater to a range of hand and appliance sizes.
Our designs are constructed using Fusion 360 software. Our prototypes were printed with the help of the 3D printing technicians from Handprints.
Figure 1. Tool Holder CAD designs
Figure 2. Tool Holder 3D printed prototypes
Figure 3. Tool Holder in use
The process in which we achieved the current designs began by contacting the occupational therapists at the Queen Elizabeth National Spinal Injuries Unit in order to gain an understanding as to what kinds of devices would be effective in aiding their work. With guidance from them, we started working on a universal tool holder design. We worked together with the spinal unit to optimise its design. We wanted the material to be flexible and soft in order to reduce agitation to the skin as well as to fit more tools. Due to the clinical setting, it also made it easier to clean and maintain sterility. These requirements led us to choose Thermoplastic Polyurethanes (TPU) as the material of choice that fulfilled our criteria. After creating a simple CAD design, we had another meeting to confirm the design, it was printed off and sent to the spinal unit for testing.
Figure 4. Example of Spinal Unit’s previous Tool Holder (6)
2. Modular Hanoi Tower
The Tower of Hanoi is a mathematical puzzle, utilising rods on a base with discs of differing size, forming a cone-shaped tower. The objective of the puzzle is to move the discs from one rod to another. In conjunction with the spinal unit, our team designed a Hanoi Tower-like device with modular capabilities to assist with occupational therapy. The concept of the Hanoi Tower was taken and enhanced to function to rehabilitate fine motor movements. This was done by adding secondary rods, around which the disc must be rotated to move smoothly through the primary rod. This device requires the execution of the processes involved in the gripping of an object, and also its manipulation via elevation and rotational movements. The modularity of the device allows the difficulty to be changed to fit the needs of the user. This can be done by increasing or decreasing the number of secondary rods, and by changing the size of the discs.
Figure 5. CAD design of Modular Hanoi Tower
Figure 6. 3D printed prototype of Hanoi Tower
The occupational health nurses initially showed us a wooden version which they had been using and we used this as the basic idea to produce our own model. The wooden device was large, heavy and hard to clean, so by producing a 3D printed version we hoped to solve both those issues. Following on from this, we had the idea to make it modular, which would have many benefits. The print for each of the sections would be faster and allow us to form a larger device, and this would help with its storage. It also gives us the opportunity to improve and add more features to the device, allowing for a wider range of actions, whereby the difficulty can be adjusted to suit the needs of the individual.
Figure 7. Spinal Unit’s wooden rehabilitation device
3. Braille Learning
Normally, learning any new script starts from getting familiar with an alphabet, so we decided that the alphabet should be a starting point of our Braille learning tools project as well. After initial brainstorming, we decided to create an alphabet on a single sheet. This seemed like the simplest and most appropriate approach – having all letters neatly ordered in a single place is a helpful reference when learning a script. However, during further discussions, it was noted that next to creating a tool for learning Braille, we also wanted to make the learning process fun. This led us to change the idea of doing a single sheet with all the letters, to doing separate tiles. Having all letters separate would allow a child to engage more with the product – play around with separate tiles, and construct words from them. On each tile, we decided to include a standard raised letter alongside its Braille equivalent. For Braille letters, standard dimensions were followed. (7) In addition, including the English letter adjacent to it would facilitate easier recognition. This would also allow children to engage in the activity together regardless of their knowledge of Braille.
Figure 8. Standard Braille Dimensions (7)
After the alphabet was finished, we decided to create some word tiles as well. Our word tiles are aimed at the early years of Primary School, so we followed the recommended word list for that level of literacy.
We also decided to create textured images next to some words to make learning Braille more fun and interesting. To create textured images for nouns we used the canvas tool on Fusion 360. The features of the picture were traced, and parts raised upwards using the extrude tool. This allows the picture outline to be felt and can be useful for children beginning to learn Braille due to progressive sight loss.
Figure 9. CAD designs for Braille Tiles
The prototypes of the parts printed well using TPU. The Braille dots were tricky in the 3D printer, and some fused slightly, so it was decided to reduce the 3D printer nozzle size for the next print. TPU plastic was used as it is very flexible so will last longer. As it is flexible it poses no risk to the child as there will be no sharp edges if it breaks. It is also nontoxic, so it will not harm the child if accidentally ingested.
Figure 10. 3D printed prototypes for Braille Tiles
The covid pandemic has inevitably had a massive effect on all aspects of life. Online working presents its challenges when trying to implement practical solutions. Detailed, accurate communication was necessary to ensure the correct dimensions were applied in the design stages. Usually, most members of the organisation would be local and have easy access to the university campus. However, due to the pandemic, many students remained at their home addresses, sometimes being in different time zones, which required more logistical organisation than it would usually. It also meant that team members didn’t have access to the 3D printers, so the person who is printing and provisionally testing the devices may not initially have in-depth knowledge of the project.
Limited funding was a setback as we did not have the freedom to experiment with printing different materials to see what would suit our desired functions best. This, alongside some of our members being new to 3D printing, meant that we were sometimes hesitant to print early prototypes. We only had the funding for a limited amount of filament, in case our design contained errors, we did not have the capacity to test countless prototypes. We were also restricted by the size of the printers that we had and the electricity needed to print larger devices. A smaller printer can only print devices of a smaller size which limits the scope of the function of our designs. We tried to get past this as much as we could by printing the devices in smaller parts and fitting them together post-print, and by printing off a smaller prototype to start.
While designing letter tiles for our Braille Learning project on Fusion 360, we found it challenging to follow standard Braille dimensions from scratch. Since word tiles will have more letters on them, we knew we had to find a simpler way to produce Braille in Fusion. Through research, we found a Fusion 360 Braille Creator. (8) This is a fantastic tool that allows the user to easily create Braille lettering by automatically creating the correct Braille layout and dimensions for words or letters. This made the process of creating word tiles much faster and more accurate.
While Handprints is primarily a biomedical engineering venture, this project brought together students from across many different fields. Medical students offer a clinical insight into the project but lack the engineering and CAD skills that are needed for the development and design of a 3D printed device. Getting to grips with CAD software can be a steep learning curve and comes with its teething problems. Furthermore, Handprints is a voluntary, student-run organisation, therefore all our work must be done alongside our university work so we were required to be able to manage our work-life balance well.
Our team aims to continue our Braille learning aids project this year. Our tiles are currently in the process of printing, and we already have a Primary School excited to test them out. After testing we will be advised on how to improve the learning pack. Once our early years Braille learning pack is complete, we hope to donate these to as many schools as possible! Furthermore, we are planning to make a Fusion 360 file of standard letter and word tiles freely accessible. This would allow schools and other institutions that have their own 3D printers to create and print customised words of their own. We made a short video explaining how to easily create a word and tactile image using Fusion 360.
We hope to continue designing new Braille learning aids and have already been thinking of new ideas. We hope to design covers for keyboards with Braille lettering to allow them to be easily adapted. Alongside this, we hope to research and develop some accessible learning games that would work well with the Braille keyboard. While researching we found that the price for Braille board games can be quite high, so we hope to redesign some classic board games on Fusion 360 to include Braille lettering.
Further modulating the design of the Hanoi tower and enhancing its features is one of our key visions. Spinal injury occurs in wide ranges of severity, therefore the patients undergoing rehabilitation in the spinal unit have motor skills that vary across a spectrum. In order to allow for increased modularity and greater range of movement, we aim to add more levels to the tower, both vertically and horizontally. These features would be even more interactive, to facilitate the rehabilitation of patients. Given that the first prototype has been successful, our team will keep in close contact with the spinal injury unit representatives. Together we will determine which 3D printing material is the best option for the design in order to maximise its efficiency. In addition, we aim to improve the connective mechanisms for the modular parts, choosing a solution that ideally would be simple but strong enough to stabilise the pieces. Our team is also working on the further improvement of the Hanoi tower design to ensure the economic utilisation of printing materials.
For the universal Tool Holder, we will be further investigating the most suitable and convenient material to use for the safety and comfort of the patient. We also aim to implement the maximum modularity for the device. That is, catering for different sizes of tools and hand sizes in the most efficient way possible. The future of our projects has strong potential to have a significant impact on spinal cord injury patients. We hope to test Tool Holder and the modular Hanoi Tower very soon in the Queen Elizabeth University Hospital at Glasgow, as soon as the existing precautions and guidelines allow us to do so.
Together with the mentioned projects, we are also hoping to develop the design of a device that assists with holding a pen, for patients with limited hand and arm movement. During the research for our projects, our team realised that there is little available for a universal pen holder design for people who have lost motor control in their upper limbs. People who want to regain their writing motor skills are restricted from doing so due to the unavailability of an assistive device to support their hand in the correct position. In many cases, people need to procure made-to-order products or manage with a DIY solution. Our team is currently trying to progress this pen project forward and create a first prototype that would allow a patient to hold a pen under at the appropriate angle to allow them to write smoothly and comfortably. There are many limitations and difficulties for the pen holder device, but our team is very optimistic. We believe that a device like this could have a significant impact on the rehabilitation of motor skills and on quality of life.
We hope that our assistive devices can be beneficial to the spinal unit in Glasgow, but also to other hospitals and rehabilitation centres in the UK and beyond. By bridging different disciplines together and under the expert guidance of Handprints, we are hopeful that our team will continue to create improved designs of our devices and have great successes in the near future.
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Zarina Issabekova (firstname.lastname@example.org) 3rd year Biomedical Engineering
Rebecca Bean (email@example.com) 2nd Biomedical Engineering
Meda Grondskyte (firstname.lastname@example.org) 1st year Product Design Engineering
Saoirse O’Keeffe-Castrelevich (email@example.com) 2nd year Medicine
Leo Huang (firstname.lastname@example.org) 1st year Medicine