OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
A B-spline surface patch having 8×8 control points net was used to represent food (jelly) for interaction with the
spoon to mimic eating with a spoon [34]. A 12×12×12 mass spring damper mesh was used to incorporate material
properties of jelly to this model, as discussed in Section II. Figure 7 shows the results of the interaction of the
jelly with the spoon [35]. The spoon was tilted at different degrees to know, what should be the optimal
inclination of the bowl part of the spoon with its handle.
(a) Jelly flowing
due to its own
weight
(b) Jelly does not
spill out of spoon,
when bowl is tilted
by 10 o .
(c) Jelly spills
out of spoon,
when bowl is
tilted by 20 o .
Figure 7. Simulation Of Food (Jelly) In A Spoon (A) Spoon Without Tilting (B) When The Bowl Is Tilted By
Ten Degree. (C) When The Bowl Is Tilted By Twenty Degree.
Due to its own weight, jelly started flowing downwards as shown in Figure 7(a). This means that if this design is
used, the user cannot eat jelly by using this size without spilling it. It is clear that the jelly is spilling from the
front portion of the spoon bowl. At this point, an industrial designer can start modifying the design in such a way
that the jelly does not get spilled. If the bowl is tilted about 10 degree in the backward (clockwise for the spoon
shown, when seen from the handle side along the handle) direction. Figure 7(b) shows the jelly put in a spoon
with tilted bowl. This time it does not spill out of the spoon and it spreads in the spoon evenly. This shows that
there was improvement in the design. The bowl was tilted by 20 degree to see if it further improves the design.
However, as shown in Figure 7(c), the jelly started flowing from the back part of the spoon. This means that by
tilting the bowl by twenty degrees, the design deteriorated rather than improving its functionality. Thus, by using
the VR environment, the spoon can be evaluated and modified at the concept state, thereby reducing the lead-time
and cost of design.
2.2.User Training
Even when a product design for a given user segment is ready, the users may require training to benefit from the
unique features of the design. Even when a variety of shapes is available for a spoon, adaptations needed for
eating may still be overwhelming for patients suffering from rheumatoid arthritis or aged people having weak
grips. An occupational therapist can help train these people. However, this would require that products are readily
available in the market. In the absence of a suitable product, it might be difficult for an occupational therapist to
train this user segment. Virtual reality environment can be used to efficiently train these users. At the same time,
an industrial designer can have better understanding of the difficulties of the user group. This can help the
industrial designer to come up with better design after receiving valuable inputs from the users.
A major challenge for patients of rheumatoid arthritis or aged people is to eat food with a spoon without spilling
it. There are primarily two reasons for spilling food from the spoon; tilting of spoon and shaking of hands while
eating with a spoon. Virtual reality environment can provide various scenarios in which a user can interact with
spoon while eating food. A variety of spoons developed during the interactive design phase can be used to
determine the best fit for the user. In the simulation study, different scenarios were considered, which included
different angle of tilt for the spoon and shaking of hands. Acceleration was imparted to spoon to simulate shaking
of hands. When the spoon gets tilted, jelly may start spilling out of the spoon. A larger tilt will increase the rate of
spilling of jelly. However, by practicing with the virtual spoon, a user can be trained to eat without spilling food.
Figure 8(a) shows the interaction of spoon and food to simulate a user tilting his/her spoon while eating food.
Different angle of tilt were considered which resulted in spilling of jelly by different magnitudes. Figure 8(b)
shows spilling of jelly when the spoon was tilted by ten degrees. The spilling of jelly increased with increased
angle of tilt as shown by Figure 8(b-c). Figure 8(d-f) show the side view of the spoon and jelly.
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