FDA QSR and Design Controls Subsystem
Jeff Skinner, Vice President of Engineering

Introduction
In 1976, the Medical Device Amendment was passed to ensure safety and effectiveness of medical devices, including diagnostic products. This amendment requires manufacturers to register with the FDA and follow quality control procedures. This act was further amended in 1990 by the Safe Medical Devices Act, again in 1997 with the Food and Drug Administration Modernization Act, and again in 2002 with the Medical Device User Fee and Modernization Act. These amendments provide for the classification and regulation of medical devices intended for human use. The Federal Food, Drug and Cosmetic Act was further amended in 2007 with the impact on medical devices being related to user fees. 

The organization of the FDA is broken down in to various centers as follows, with the FDA QSR for medical device design falling under CDRH:            

• CDRH – Center for devices and radiological health
• CDER – Center for drug evaluation and research
• CFSAN – Center for food safety and applied nutrition (which also covers cosmetics)
• CBER – Center for biological evaluation and research
• CVM – Center for veterinary medicine

Regulations implementing the Federal Food, Drug and Cosmetic Act (The Act) are found in title 21 of the Code of Federal Regulations (21 CFR) parts 800 – 1299.  The Act establishes a classification system for devices based on risk. There are three classes of devices:

• Class I: low risk and require only general controls
• Class II: medium risk and require both general controls and special controls
• Class III: high risk requiring general controls and pre-market approval

Within the device classification system, in addition to the device class, all devices are also assigned a regulation number, a classification name and a product code. It is however the device class that determines the level of regulatory controls required.

FDA QSR Overview:
Quality system requirements of the FDA consist of seven different subsystems:

1. Management Subsystem
   
2. Design Controls Subsystem
   
3. Production & Process Controls Subsystem
   
4. Corrective & Preventive Actions Subsystem
   
5. Equipment & Facility Controls Subsystem
   
6. Records, Documents & Change Control Subsystem
   
7. Material (purchasing) Controls Subsystem

Design Controls Subsystem 21 CFR 820.30:
The purpose of design controls from the perspective of the FDA is to control the design process to assure that devices meet user needs, intended uses and specified requirements. Design controls apply to all Class II and Class III devices and to the following Class I devices:

• Devices automated with computer software
• Tracheobronchial suction catheters
• Surgeons gloves
• Protective restraints
• Manual radionuclide applicators
• Radionuclide teletherapy source

From a macro perspective, design controls consist of:

• Design and Development Planning: A definition of the tasks necessary in the design process and who is responsible for completing them. A project schedule (Gantt chart) would fulfill this requirement.
• Design Input: – This means device requirements, which must also address user needs including patient needs and intended uses. A process is required to address incomplete, ambiguous or conflicting requirements.
• Design Output: This is defined as the results of design and development activity at each phase of the project. Documentation of design output must show conformance to the relevant design input requirements.
• Design Review: – Formal documented design reviews must take place at appropriate times within the development cycle. What constitutes appropriate times is left to the manufacturer to determine.
• Design Verification: Verification testing confirms that the design outputs meet the design input requirements. Methods used to verify the design must be documented in the design history file. Verification testing is intended to occur at various stages in the development process, not at a single point. Verification can take several forms, testing, inspection or analysis
• Design Validation: Validation testing ensures that the device conforms to user needs and intended functions. Testing must be performed on devices representative of production units. Guidance suggests that this testing be performed on initial production units sometimes referred to as pre-production or pilot production.
• Design Transfer: Transfer of a design out of engineering and into production requires that a production process be created. This production process must ensure that the product’s specifications can be reliably met in the manufacturing environment. Device yields must be sufficient to justify manufacture of the device.
• Design Changes: Change control involves two major areas, document control and change control. Changes must be tracked to completion and the issue or issues that forced the change must be resolved. In order to meet these main objectives, a document trail must be maintained demonstrating both the issue and its complete resolution including a review of the risk analysis. The real key here is when to invoke the change control process.