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Thermo-responsive hydrogel-based circular valve 471

20.5 Conclusion and future work

In conclusion, both the TRHV and the SMAHV present translatable functionalities in terms
of application into the CBI process. Both can achieve multiple lumen areas based on stimuli
variation to achieve at least three states, which are the current levels of sterile solution flow
rate moderation present in CBI guidelines. However, both require additional external
equipment set up to provide the stimuli. The TRHV requires an additional cooling system
downstream due to the temperature stimuli not being isolated from the CBI system. In terms
of the time for actuation, the SMAHV has a much lower actuation time (2 5 seconds) than
the TRHV (100 seconds). However, if coupled with a proper sensing system, it could
drastically improve the regulation quality and frequency compared to the current frequency,
which is dependent on the nurses’ rotation and shifts, which range in the order of minutes to
hours. The valves at the present stage are still unsuitable for clinical use.
To be used clinically, the TRHV and SMAHV need to be improved and coupled with an
appropriate sensing system. The current designs of TRHV and SMAHV are unsuitable for
clinical use due to the lack of consistency. For the TRHV, the chemical composition needs
to be modified to create a more responsive and consistent thermo-responsive valve. Testing
with a variety of temperature variations and valve dimensions to determine ideal
dimension temperature relationships needs to be done to obtain an accurate and more ideal
valve with set temperature points to achieve target lumen areas to regulate the flow of
sterile solution properly. For the SMAHV, testing needs to be conducted to determine ideal
SMA diameter and hydrogel stiffness relationships. In testing the stiffness of hydrogels, the
composition of the hydrogel may need to be changed. Once that has been accomplished,
testing needs to be done to determine input current and lumen area relationships to establish
accurate input current for set SMAHV lumen areas. More research needs to be conducted to
compare the use of SMA springs compared to SMA wires in the CBI process valve
application. Lastly, to create an automated CBI process, an appropriate sensing system
needs to be incorporated with the possible effectors, TRHV and the SMAHV, to quantify
gross hematuria levels in urinary discharge.

References

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