Figure 13. 3D printed assistive technologies designed by Physical Therapy graduate
students using clay that was later 3D scanned and printed. 27 These include a wrist brace
(left) hand spreader (center) and pencil grip (right).
Figure 12. Some examples of objects generated using Reprise and the original designs
from our survey that inspired them (shown in insets). Clockwise from top left: a wrapper
for a fork; a lever for controlling a spray bottle; an anchor for using a tool with one hand;
a handle for a key.
PARTs’ basic abstraction is
functional geometry. Functional geometry
incorporates the modern programming concept of classes, which encapsulate data and functionality, making
it easier to validate and mutate data,
manage complexity, and support
modularity. Specifically, it includes
assertions that test whether a model is
used correctly and integrators that mutate the larger design context. These
abstractions are available in an interactive graphical form and increase
model usability and reusability.
The PARTs framework can flexibly
address a wide variety of 3D modeling challenges for non-experts. It supports many tasks in-situ that are normally handled in separate dialogues or
tools that non-experts may not find or
understand how to use. While PARTs
intentionally uses simple concepts,
many model-specific design goals can
be encapsulated using its assertions
One of the benefits of PARTs is its
generality. Reprise and Encore represent tools that provide specific, carefully constructed solutions to important problems. However, they were
each created outside the traditional
3D-modeling context (CAD tools).
In contrast, PARTs is integrated into
the professional Autodesk Fusion360
Discussion and Future Work
The body of work we described in
this article outlines the beginning of
a path for empowering end users to
design pleasing and functional assistive technologies to share with others.
Despite the many opportunities for
consumer-grade, desktop 3D printers
to solve accessibility challenges, we
have observed few examples of end users adopting these solutions. This slow
adoption is troubling, and we must
delve deeper to understand the impact
of fabrication on assistive technology.
Here, we discuss the stakeholders currently engaged in AT production and
the barriers they face in adopting fabrication technology. We then discuss the
importance of understanding use and
abandonment of AT that has been 3D
printed. Finally, we examine potential
models for the sustainable production
and personalization of digitally fabricating assistive technology.
Stakeholders. To fully understand
the potential for new fabrication
technologies to transform AT use, we
must understand the stakeholders
involved in the design, production,
and use of do-it-yourself (DIY) AT.
Most existing research in this area focuses on the design of the AT, DIY-AT
end users, and volunteers who help
with fabrication. Studies have explored AT’s efficacy3, 19 and the potential for people with disabilities to
participate more directly in AT fabrication. 15, 18 The volunteer communities that supports DIY-AT have also
been thoroughly studied, both by reviewing the artifacts they produce5, 9
and by interviewing members of communities such as e-NABLE. 30 These
communities tend to be dominated
by people with strong STEM backgrounds and education. This lack of
diversity reveals opportunities to expand who can be a maker, particularly in the AT context.
In contrast, many of the stakeholders involved in the more traditional AT
ecosystem do not have a STEM background. These may include educators,
clinicians, family, and students (for
example, Buchler et al. 6, 7) and physical therapists (for example, Hofmann
et al. 13 and McDonald et al. 27). Further
study is needed to explore how best to
support these stakeholders.
Our own plans include teaching
physical therapists to use fabrication
tools, expanding on the methodologies developed by McDonald et al. 27
and Buehler et al., 6 who had therapists
design assistive technology using clay
that is later 3D scanned. Figure 13 depicts custom AT recently co-designed
by older adults and physical therapy
In contrast to DIY-AT communities, much less is known about AT
making in medical settings. Clinicians are using fabrication for more
than just assistive technology. For