The new article highlights the aspects related to design considerations including control mechanisms to be implemented.
Table of Contents
The Food and Drug Administration (FDA or the Agency), the US regulating authority in the sphere of healthcare products, has published a guidance document describing technical considerations for medical devices with physiologic closed-loop control (PCLC) technology.
The document provides an overview of the applicable regulatory requirements set forth under the existing legal framework, as well as recommendations and clarifications to be taken into consideration by medical device manufacturers and other parties involved to ensure compliance thereto.
At the same time, it is important to mention that provisions of the guidance are non-binding in their legal nature, nor are they intended to introduce new rules or impose new obligations.
Moreover, the authority explicitly states that an alternative approach could be applied, provided such an approach is in line with the respective legislation and has been agreed with the authority in advance.
The scope of the guidance covers, inter alia, special considerations related to medical devices utilizing PCLC technology.
Design Parameters and Safety
As explained by the authority, the engineering and design of PCLC devices covers multiple aspects and approaches.
They can include methods of risk mitigation, system fault handling, open-loop modes during faults, and supervisory layers dictating system transitions.
Whatever design approach is chosen, it is vitally important to ensure that the device’s safety and performance remain transparent and consistent.
The end goal should be to navigate and manage challenging clinical scenarios such as patient variability or component malfunction, ensuring they can be verified and rectified.
Components of a PCLC Device
According to the guidance, a standard PCLC device is constituted of three main components:
- Sensor: Measures a physiological variable from the patient.
- Control Algorithm: Dictates how the device operates.
- Actuator: Delivers or removes energy or an article to the patient.
Manufacturers must adhere to certain specifications when describing these devices. These specifications can be found detailed in the appropriate standards, e.g., IEC 60601-1-10.
As further explained by the FDA, in premarket submissions, a comprehensive description of these components and their interconnection is required.
A functional block diagram showcasing the relationships and transitions between the physiological variable, sensor, control algorithm, actuator, and the patient will also be beneficial for the authority when reviewing the application.
Furthermore, details about automated modes, user interactions, therapy phases, and therapeutic objectives should be elaborated as well.
Specifications and Compatibility
According to the guidance, for PCLC devices designed to deliver drugs or other regulated medical products, it is important to highlight how the device’s design, especially its control algorithm, aligns with the product’s labeling instructions.
Additionally, device labeling must give information about its compatibility with the article it is intended to deliver.
Components of the PCLC device can range from specially designed parts to existing medical devices, such as infusion pumps.
Their specifications must ensure optimum function as a part of the PCLC device. When a stand-alone medical device is used as a component in a PCLC device, its performance might differ from its operation (when used separately).
It is crucial to consider FDA guidelines when integrating pre-approved devices into the PCLC system.
Specifications and Compatibility
According to the guidance, for PCLC devices designed to deliver drugs or other regulated medical products, it is important to highlight how the device’s design, especially its control algorithm, aligns with the product’s labeling instructions.
Additionally, device labeling must give information about its compatibility with the article it is intended to deliver.
Components of the PCLC device can range from specially designed parts to existing medical devices, such as infusion pumps.
Their specifications must ensure optimum function as a part of the PCLC device. When a stand-alone medical device is used as a component in a PCLC device, its performance might differ from its operation (when used separately).
It is crucial to consider FDA guidelines when integrating pre-approved devices into the PCLC system.
Control Algorithms
The authority additionally emphasizes the importance of control algorithms for the overall functionality of the PCLC device.
According to the document, it determines the automated actions by comparing feedback from sensors with reference values. The algorithm’s purpose is to adjust the energy or article delivery, ensuring the device meets clinical performance specifications.
Its design should account for factors such as the patient’s drug sensitivity or any elements affecting the drug dynamics.
The control algorithm must also be robust enough to operate amidst patient variability, disturbances, and other potential hazards.
Multiple control algorithms might be incorporated within a device, each serving specific functionalities.
In situations with multiple algorithms, it is crucial to ensure smooth transitions between them, clarity in user interfaces, and defined criteria for mode switching.
The authority also mentions that multiple PCLC loops could operate simultaneously provided each of them is controlling different physiological variables.
These loops must be integrated mindfully to prevent potential system hazards.
Design Scenarios for Control Algorithms
According to the guidance, there are several methods manufacturers can employ when designing control algorithms:
- Mathematical Model-Based Approach: This method utilizes a mathematical model that characterizes the underlying physiological dynamics and potential variabilities.
- Rule-Based Controller: This is based on clinical guidelines or best practices, relying on a set decision table. It is vitally important to align the implemented rules in the algorithm with clinical studies and best practices.
- Machine Learning (ML) Approaches: Algorithms can be designed using ML techniques, or ML can be integrated into the design. In premarket submissions, manufacturers should detail the ML model’s structure, training processes, and the representative nature of the patient data used for ML.
Conclusion
The guidance additionally emphasizes that designing PCLC devices requires a deep understanding of both medical and technical matters, from ensuring the safety and consistency of these devices to understanding the operational details of their control algorithms.
The document highlights the key points medical device manufacturers should take into consideration with respect to design-related matters and outlines the approaches to be applied.
How Can RegDesk Help?
RegDesk is a holistic Regulatory Information Management System that provides medical device and pharma companies with regulatory intelligence for over 120 markets worldwide. It can help you prepare and publish global applications, manage standards, run change assessments, and obtain real-time alerts on regulatory changes through a centralized platform. Our clients also have access to our network of over 4000 compliance experts worldwide to obtain verification on critical questions. Global expansion has never been this simple.
