Figure 1: Process overview of an integrated continuous antibody
production with perfusion bioreactor system, continuous capture system
and a system for polishing, inspired by Schwartz et al 2022.
The integrated continuous process platform was well suited to be a
testbed for studies of novel processing step, new analytical tools, data
management, automation, real-time monitoring and control, and other
digital solutions. Based on experiences a general platform, see
Andersson et al 2022, for development studies and validation of digital
solutions needs following features:
- Local supervisory controller for handling general setups with an open
and flexible architecture for introduction of novel automation,
feedback control and computational tools
- Network of supervisory controller with a general communication
protocol for the configuration and operation of complex processing
systems
- Automated support systems to run the continuous processing system
almost autonomous, such as buffer management and quality analysis
- Common real-time database together with general tools for data
handling and analysis that can handle heterogeneous, asynchronous and
distributed data
- Embedded tools that can handle model based simulation, monitoring and
control for digital twin applications
A lab-scale platform that contained all these features made it possible
to implement and validate novel digital solutions with minimal
resources. The lab-scale size reduced the amount of material needed to
do long-time runs. Automation of the processing together with the
support system means that operation can be unmanned or remote. The
previous work was only manned during office hours, unmanned during
nights and over weekends. This resulted in that efforts could be focused
on implementing digital solutions at different levels of the complex
system, some will be discussed below.
Local supervisory controller
The instruments are controlled with a local supervisory controller. An
overview of the architecture can be seen in Figure 2, where it’s divided
into an orbit kernel, user code and application library. The user
configures the system and designs a script defining the sequence of
phases that should be executed, where each phase consists of the methods
from the application library. The application library often shares many
methods but is unique for every specific setup. For each local orbit a
system configuration is defined and a method library for the current
setup. The controller also handles tasks such as sampling, database
communication and network communication with other orbits.