The follow-up session reconvened the participants from the prior session. OTs will try and evaluate the printed hand ATs in this session.
Facilitating the identification of appropriate grips based on distinct pathologies and the specific requirements of users.
The image to the right displays the grips printed using our recommended settings for PLA, PETG, and TPU. The infill percentage, layer height, and wall line count can be adjusted according to specific requirements, and the test samples were designed with time efficiency in mind. It is important to note that different printers and nozzles may require varying temperature settings.
The advent of presents a significant opportunity to and of augmented ATs. This innovation enables the rapid fabrication of diverse adaptations within a . And studies have shown the practicality of using 3D printing as an effective tool in both rehabilitation settings and the clinical manufacturing of assistive technology.
10 - 15 minutes
Thermoplastic Polyurethane (TPU)
regain
cost and time efficiency
SUS survey
hand AT user profile
Nonetheless, the of professional Computer-Aided Design (CAD) software for creating printable 3D models poses a for novice users.
Customization
Polyethylene Terephthalate Glycol (PETG)
Qualitative Analysis - Interface
detail
Printed Grips
Add a section to allow changing .
filleted
What is Assistive Technology?
During the initial session, OTs had an opportunity to manipulate the computational tool and develop a customized adaptive grip that suits the user's needs. Prior to this session, participants were required to complete a . This profile encompasses a comprehensive range of user-specific details such as age, gender, medical pathologies, occupation, various assessments (strength, dexterity, range of motion, sensation). OTs will also complete a regarding the interface usability and semi-structured during this session.
devices that meet the personal needs
customize
PLA
2 - 3o
240°C
Light weight
Oval Cylindrical Grip
Spinal cord injury
Hooks
PLA
Designed for
platform
hard to clean
Visualization
Valuable insights and suggestions from different perspective are provided by occupational therapists.
Current Situation
Bended Grip
Specify the of measurement.
intuitive interface
shape handle to prevent hand sliding off onto the spoon.
ATs can be acquired
Assistive technologies (ATs) enable individuals with disabilities to participate in (ADL) that would otherwise be unattainable for them.
EaseGrip offers three unique textures designed to enhance grip through for individuals with reduced hand sensation. Each texture is crafted for ease of cleaning and visual appeal, ensuring functionality meets style.
Our opportunity is to develop an for OTs, facilitating the digital design of grips for 3D printing. This aims to offer a more durable and cost-efficient solution for AT users.
Cost & Time Effectiveness
inside
Using for easy visualization of the immediate effects on the display.
Strengthen the sense of size in the virtual 3D display.
weight
Enhance navigation and comparison of different grips.
robustness
Contact PageContact
Contact PageHome Page HPContact
Contact PageGRACE LI
Home Page HPHome Page HPWork
Home Page HPHome Page HPWork
Home Page HPextend the
not durable and can pose hygiene
unit
intuitive
Costs
infill
Enabling OTs to customize pre-designed adapted grips according to dimensions, materials, colors, and weights.
Oval Cylindrical Grip
heavy
problems
By employing a color swatch, OTs can alter the grip's color and instantly see the rendered effects on the real-time display.
Curvy Texture Grip
medium
Ability to switch between imperial and metric units.
Grip with Hooks
“If you had a Dropbox … if you had only one screen and then you could choose and maybe you could pop up different ones... I could pull up the three, but at the end of the day I can only manipulate one at a time... in one screen then I would have a better rhyme or reason for why I picked this versus that one and be able to contrast them side by side.”
temperatures
Ease of cleaning is critical in the design of adapted grips for eating utensils.
Real-Time Interactive Display
Comparison between grips
Layer height
Search pre-designed grip
light
Follow-up interview
Easy to clean
The interface has been refined based on feedback from OTs and an AT engineer at a local clinic, making it more and .
Have on the surface to provide sensory feedback.
TPU is a flexible, elastic material with a soft-touch surface. The recommended printing temperature is 225-240°C. Figures g-i show that printing at provides the smoothest and cleanest surface with minimal wadding and well-defined layers. At higher temperatures, TPU becomes stickier, causing more dents and bumps on the top surface (h). The internal view (i) indicates increased wadding and slight deformation at higher temperatures. TPU’s internal structure is designed for flexibility and strength, accommodating bending better than rigid materials. Like PLA, higher temperatures make adhesive removal more challenging.
risk of warping
participants
78.96
However,
Providing an intuitively designed comparative analysis of grips enables OTs to make expedited, informed decisions.
interface and design
Supplementary instructional documentations outlining the setup procedures for the 3D printer should be attached to the downloaded grip model file.
real-time display
Qualitative Analysis - Interface
affordable 3D printing technology
~ 50 min | 5 participants
Straight-line Texture Grip
slider scale
Designed for
Round Cylindrical Grip
TPU
Straight-line texture
Hooks + flared
Muscle weakness
Medium weight
interior
mechanical strength
Scroll down
Usefulness
The dimensions are categorized into two sections: and . The exterior part enables OTs to modify the grip's diameter and height to suit the patient's hand, while the interior dimensions are tailored to accommodate the utensils.
Customization - Grip Color
Opportunity
In individuals with hand impairments, reduced hand mobility and grip strength, attributed to aging and various pathologies, can have a detrimental impact on the performance of activities of daily living, ultimately .
color
Recommended settings
strap
Designed for
Neuropathy
Light weight
Polygon Cylindrical Grip
PLA
Therefore,
Handle Design Suggestions
The display will reflect any changes in parameters and color on time. It also enables OTs to use their mouse or touchpad to drag or zoom for a detailed view of the grip.
Session 1
design guideline of
density
Thoughtfully designed
sensory
Parametric Software
Pros
of EaseGrip
User-centric
not durable
System Usability Survey (SUS) Result
Flared Grip
Offering an immediate and interactive real-time visual representation to promptly demonstrate any modifications enacted by OTs.
Storyboard
This project aims to showcase the feasibility of a proof-of-concept that empowers occupational therapists in fabricating customized adaptations of assistive technologies to effectively address the distinctive requirements of individuals with hand impairments. The platform enables OTs to modify pre-designed models of utensil grips, serving as
200°C
Interface design requirements were outlined to detail the essential components needed.
The wall line count affects the of printed items. We evaluated 2, 4, and 6 wall lines [m]. More wall lines enhance strength but also increase weight, print time, and cost: 2 layers used 6g of material and took 42 minutes, 4 layers used 8g and took 51 minutes, and 6 layers used 9g and took 61 minutes.
Qualitative Analysis - Interface
The first iteration is designed to provide OTs with a better comprehension of this type of tool, while also helping us in identifying the essential parameters.
hand assessments, specific
of EaseGrip Interface
through commercial or by them or everyday items to cater to specific individual requirements.
parametric software
Manufacture
extensive parameters
Designed for
Medium weight
Hooks + flared
Round Cylindrical Grip
TPU
Diabetic neuropathy
Curvy texture
Oval Cylindrical Grip
Heavy weight
Parkinson
Designed for
PLA
Straight-line texture
Straight-line texture
Light weight
Round Cylindrical Grip
Designed for
Central cord syndrome
PLA
Upon computing the SUS scores for each participant, the mean score across 12 participants is found to be . Generally, scores exceeding 68 were considered as positive feedback. Consequently, a mean SUS score of 78.96 indicates that the users perceive the system as , , and , .
Interface Design Suggestions
easy-to-clean texture
of EaseGrip Interface
high degree of customization
off-the shelf solution: It is of users. Because mass-produced assistive devices are primarily designed to meet the needs of the general population and may not be suitable for individuals with specific and unique requirements.
user-friendly
dimensions
download process
3D printing and experiments
Session 2
Curvy texture
PLA
Stroke
Medium weight
Designed for
Round Cylindrical Grip
Hooks
handle
material
exterior
An affinity diagram was utilized to organize and categorize the feedback provided by occupational therapists during the usability test. Occupational therapists have confirmed the effectiveness of EaseGrip, highlighting its and .
3D printing proficiency requires time and is not within OTs' expertise. Safety, durability, and hygiene are critical as OTs assess its potential. This part explores the performance and optimal settings of three common 3D printing materials— , , and —using cylinders as adapted grips.
This interview is to sought OTs’ opinions about the and designs included in the first iteration. And affinity diagram was adopted to analyze data.
Before creating the grip, OTs are required to measure specific dimensions (A, B, C, E, and F). These measurements are correlated with the software's parameters to ensure precision in the design. OTs can also adjust parameters freely depends on the needs.
weight
Parametric Software
The advent of affordable 3D printing technology presents a significant opportunity to improve the durability and extend the lifespan of augmented ATs. This innovation enables the rapid fabrication of diverse adaptations within a reasonable cost. And studies have shown the practicality of using 3D printing as an effective tool in both rehabilitation settings and the clinical manufacturing of assistive technology.
Qualitative Analysis - Interface
OTs expressed
Refined
improve the fit
Materials used for adaptation making like foam, Velcro, tape, sponge, and popsicle sticks are . While thermoplastics offer greater strength, they come with a and the in high temperatures, such as inside a car.
Percentage of infill
Co-Design
visually appealing
OTs have the option to select the grip's weight as (~95g) , (~180g), or (~250g), depending on the patient's needs. This weight adjustment is achieved by changing the infill percentage of the filament during the 3D printing process.
Adjustable weight using a slider scale.
usable
higher
Inclusive
cost
I tested each material's minimum, middle, and maximum , considering the wide temperature ranges specified. vary: PLA and PETG are $0.022/gram, while TPU is $0.124/gram. I also evaluated , percentages, and wall lines to optimize print , , and . The prints were created on UltiMaker printers using Cura, with time, cost, and status recorded to visually classify key parameters for AT fabrication.
Ergonomics
develop
layer
Use of for better support.
PETG
Adjusting the infill percentage alters the , , and of printed items. We tested infill percentages ranging from 20% to 100% [l]. Higher infill percentages extend print times: 20% took 43 minutes, 60% took 58 minutes, and 100% took 87 minutes. Increased infill also raises material usage and cost: 20% used 6g of filament, 60% used 11g, and 100% used 16g.
of EaseGrip
prescribing
reasonable cost
“explaining like what the material is ... because when it says flexible or rigid, I don't know like what necessarily they are talking about with flexible or rigid.”
Nevertheless,
Add explanations of different material options.
variety of grips
, , and the are the most important.
feedback
Future...
PETG is a rigid, food-safe material known for its durability, thermal stability, and chemical resistance, outperforming PLA in these areas. The recommended nozzle temperature for PETG is 220-260°C. Figures d-f show that printing at produces the shiniest surface, while 220°C yields the smoothest finish. Higher temperatures create a more matte surface and slightly more pronounced seams. The top view (e) reveals the clearest top structure at 220°C, while higher temperatures cause more internal crystalline fractures. The sectional view (f) indicates that PETG has cleaner internal structures than PLA, but higher temperatures can increase internal wadding.
requirements, and health condition.
Occupational therapists have also validated the uniqueness of EaseGrip, emphasizing its , , and the .
Four Different Shapes of Grip
3D printing
Suggestions
“I do think using slider scale instead of like option 1, 2 or 3”
12
Flared Grip with Hooks
Outside dimensions
EASEGRIP
Add option for specific needs.
Design
TPU
Flexible
3D
Moving forward, addressing the feedback from OTs highlighted in the usability tests is a key priority. Looking ahead, we envision transitioning this product to an online platform, which will simplify access significantly. Instead of requiring the download of Grasshopper, OTs and AT users could achieve the same functionalities directly through a dedicated website. This transition not only streamlines the user experience but also broadens accessibility, allowing for more seamless integration into professional practice and daily use.
Hooks
Designed for
Stroke
Oval Cylindrical Grip
Straight-line texture
PLA
Heavy weight
complexity
Build-up grip tailored to specific pathologies, needs, and hand conditions were printed using the Ultimaker 3/5s printers.
Four distinct grip shapes offer a diverse range of options to meet varied purposes and user requirements.
Polylactic Acid (PLA)
intuitive
enhance usability
PLA is a versatile and affordable material known for its durability and safety. I used 2.85mm MatterHackers white PLA with a recommended nozzle temperature of 180-220°C. The results (Figures a-c) show that printing at provides the smoothest surface and uniform layer distribution. Although seam differences are minor, the 200°C sample exhibits more consistent seams. The top view (b) shows noticeable gaps at 180°C, while the sectional view (c) highlights a cleaner internal structure at 200°C with solid support and fewer adhesions. Higher temperatures, however, make adhesive removal more challenging and may produce sharp edges.
interview
Avoid technical jargon on demonstrating materials.
activities of daily living
heights
strength
are now highlighted for better visibility, while parameters like weight and material have been , as these can be adjusted directly in 3D printing slicing software based on available materials. The has been streamlined—OTs no longer need to access Rhino software to download the generated models. Instead, it's a simple two-step process: bake the model in Grasshopper and save it directly to their computer.
Cost-effective
Occupational therapists also pointed out the , , , and as crucial features for their quick comprehension and everyday use.
Human-Computer Interaction UI/UX Design Paper admitted to ASSETS '23 Conference
A Need
Display
Practical
removed
Customization - Grip Material
Anthropometry
225°C
hard to find
Requirements
Parkinson
TPU
Heavy weight
Oval Cylindrical Grip
Designed for
quality
interface
Adaptive Grips
Hygiene
satisfying
First Prototype iteration
lifespan
Include more different types of grips.
--- Click to view other works ---
OTs can select between flexible and rigid materials.
OTR/L
improve the durability
User Interface
Additionally, I've the edges of the hooks for enhanced safety and a more comfortable wearing experience.
Quantitative analysis - Interface
off-the-shelf solutions
reflecting positively on the user experience
Why hand?
Three Distinct Textures
parameters
They are...
critical role of user engagement
Incorporating static anthropometric data during the design process of the adapted grip.
Enhancing a precise comprehension of size on the interface through the display of diagrams or the inclusion of a reference object for scale comparison enhances user clarity.
Self Explanatory
maintain
challenge
Customization
deformation under high temperature
About the design
modifying
years as OT professionals
Customization - Grip Weight
Hooks
Light weight
Designed for
Oval Cylindrical Grip
Neurological deficits
Straight-line texture
TPU
So occupational therapist (OTs) assists individuals with mental, physical, or emotional impairments by , ATs to , , or the skills necessary for everyday life and working.
The design steps for creating a 3D model of a desired hand grip. After conducting a clinical assessment of an individual’s hand, OTs can begin the process by selecting the appropriate grip type. They can then customize the design by choosing different surface textures, colors, and other features. Next, they can adjust the parameters based on the individual’s hand measurements and the specific utensil to be used. Finally, they can specify the 3D printing options based on our recommended properties, including the device’s weight, material, printer set up, and download the file for printing.
Round Cylindrical Grip
The design process should thoroughly take into account the diverse needs and pathologies of different users.
quality
Rigid
Customization - Grip Dimensions
Arthritis
Straight-line texture
Designed for
Bended Grip
TPU
Hooks + flared
Light weight
Uniqueness
Selections
45 - 80 minutes
Based on feedback from OTs, I have designed four different grip patterns to accommodate a wide range of needs.
Wall line count
Customizable
necessity
tailoring
: Soft PLA, TPU (certain degree of TPU is dishwasher safe) : PLA, ABS, PP (dishwasher safe), PETG (dishwasher safe), ASA (dishwasher safe)
examples of ATs, based on individuals’
ease of use
“Maybe like an example of where the X&Y are... Just give a correlation of a scale... or a map like a legend.”
weight
height
Customization - Grip Designs
What would OTs do?
Smooth Grip
OTs often employ various materials such as foam, tape, Velcro, cardboard, string, thermoplastic, and sponge to off-the-shelf or everyday objects, aiming to and for individuals with specific needs.
Flared
“I know that millimeters are probably the most accurate. So I understand using millimeters. However, I could see my coworkers being like why is this not inches.”
Light weight
Designed for
Oval Cylindrical Grip
Stroke
Hooks
TPU
Beyond my expectation
UPGRADED PROTOTYPE
Layer height significantly influences the and of 3D printed items. We tested layer heights of 0.1mm (fine), 0.15mm (normal), and 0.2mm (fast). The side view [i] shows that smaller layer heights produce smoother textures and surfaces, reducing seam unevenness. The sectional view [k] indicates that finer layer heights also minimize internal adhesions. However, while thinner layers offer better quality, they increase print time: 0.2mm took 32 minutes, 0.15mm took 41 minutes, and 0.1mm took 59 minutes.
Regular Grip
have certification of
Polygon Cylindrical Grip
The interface design should demonstrate intuitiveness and harmonize with the OTs' professional workflows and vocabulary.
restricting personal independence
expensive