By Jason Maurer (Blue Line/Onlinestrategen.dk)
Cleanrooms, regardless of their ISO 14644-1 class, are characterized
by the rigor and efficiency of their cleanliness routines and the reliability
of their requisite technologies (e.g., airflow systems, pressure seals, computers).
Mobile human–machine interface (HMI) workstations specifically designed for
cleanroom use are a comparatively recent invention. Although trolly-mounted
computers have been in use for more than a decade, they have typically relied
on designs used in patient care facilities; as such, they were not designed to
stand up to the rigorous cleaning practices characteristic of cleanrooms. In
this post, I will explain the benefits of mobile HMI workstations in low-to-mid
class cleanrooms (ISO 14644-1 classes B–D), particularly in terms of what they
allow workers to do.
Designed For
Continuous Operation
As I explain in an earlier
post, mobile cleanroom HMI workstations are designed from the bottom-up to
ensure easy but rigorous cleaning, possessing good ingress protection (IP65+)
and typically being resistant to even the harshest detergents. They are also
designed for continuous use during an entire 8-hour shift: workers can switch
them on and begin working as soon as they complete decontamination and donning
personal protective equipment. Continuous (24/7) uptime is a necessity in
production—even a brief shutdown in monitoring or equipment due to power
outages or other electrical faults can lead to millions of dollars in lost
batches and insurance payments. For that reason, mobile cleanroom workstations
rely on hot-swap battery systems. That is, their batteries can be charged
externally and then quickly inserted into the unit without loss of operation,
thereby enabling workers to perform quick and simple handover between shifts.
Sensitive,
Optically Bonded Touchscreens
Touchscreens are in widespread use
in our daily lives, but they are often despised by cleanroom workers because
they tend to be insufficiently sensitive to use with multiple layers of gloves
(a necessity for class B and C cleanrooms). Luckily, mobile cleanroom HMI
touchscreens have been specifically calibrated for these higher-class
cleanrooms, thereby ensuring that workers can utilize them without needing to
remove gloves while also making sure that they do not react to non-user inputs
(e.g., errant water drops during cleaning). This drastically eases cleaning
routines and further limits the possibility of contamination. The highest
quality touchscreens (see Figure 1) also feature auto-calibration, which helps
to reduce translation, scaling, and rotation errors (1) https://www.embedded.com/how-to-calibrate-touch-screens/)
and ensures a smoother user experience. Workers can thereby ensure that their
work is completed with minimal interruption and frustration.
Figure 1. Auto-calibrated
touchscreen
Moreover, cleanroom HMI touchscreens are built with optical bonding to
ensure that they can be cleaned with liquids without worrying about the buildup
of condensation over time, which can lead to fogging and the need to replace.
Accordingly, cleaning agents can be left for longer periods to ensure
decontamination.
One Size Fits All
In smaller scale production cases—something
that is becoming more common as companies branch out in personalized medicine
or open up smaller facilities to improve local distribution—mobile cleanroom
HMIs excel for their flexibility and utility. Workers do not have to contend
with multiple HMIs, for one thing. They can move the workstation with them
throughout the cleanroom, meaning that production can begin that much more
quickly at the start and for far lower costs. This is especially useful in
larger class D cleanrooms, where, even a few years ago, multiple HMIs might
have needed to be installed. Workers can bond with a particular workstation
that then travels with them as they complete their tasks throughout the
cleanroom.
Conclusion
Cleanrooms require technology suited
to their need for efficiency and cleanliness. We expect that the use of mobile
cleanroom workstations will increase in line with our knowledge of cleanroom
science and best practices, given their tailored designs.
References
(1)
https://www.embedded.com/how-to-calibrate-touch-screens/
Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)