How Mobile HMI Workstations Enhance Cleanroom Practices

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/)