Draft Guidance of 3D Printing Medical Devices issued by FDA on May 10, 2016

Draft Guidance of 3D Printing Medical DevicesIssued by FDA on May 10, 2016

Christina Huang2016/05/18

Overview

To outline technical aspects of an AM device that should be considered through the phases of development, production process, process validation, and final device testing.

Scope: Design and manufacturing considerations Device testing considerations

BiologicalCellularTissue-based products

AM Classifications

Powder fusion Stereolithography Fused filament fabrication Liquid-based extrusion

Advantages: (1) using patient’s own medical imaging(2) ease in fabricating complex structures

Concerns:(1) relative lack of medical history experiences(2) challenges in characterization and assessment

Design and Manufacturing Process Considerations Standard-sized device

Compare the desired feature size to final device Document dimensional specifications and tolerances Check pixelation caused by mismatch

Design and Manufacturing Process Considerations Patient-matched device

Refer to “customized” devices not custom devices, which meet FD&C requirement: ≦5 pcs/yr of a type

Often made by altering features of the standardized Clearly identify design parameters and its range, and which of

these can be modified for patient-matching


Effects of imaging (recommend): 1) note the range of deformation experience by the target location/tissue vs. reference image2) consider the potential time to produce since patient anatomy changes over time


Interacting with design models (recommend): 1) design software identify the iteration of changes2) all medical devices and accessories is validated

Design and Manufacturing Process Considerations Software workflow

File format conversions:1) test all file conversion with simulated worse-case2) software changes may trigger revalidation3) final files for printing should be maintainedas AMF format in ISO/ASTM 52915 “Standard specification for additive manufacturing file format”


Digital device design to physical device:1) build volume placement: distance between each component, orientation of each component, difference between machines affect final properties


Digital device design to physical device:2) addition of (temporary) support material: location, type, number affect geometric accuracy and mechanical properties analyze geometry and other requirements

Design and Manufacturing Process Considerations


Digital device design to physical device:3) slicing: layer thickness choice (depends on surface texture, bonding ability, powder sensibility)4) build paths: document building path space between each building path, path speed impact the quality of final device


Digital device design to physical device:5) machine parameters and environmental conditions:

power of energy system and energy densitybuild/beam speed and pathfocal point or nozzle diameter, etc

use qualified machine with qualified installation

Design and Manufacturing Process Considerations Material control

Starting material: document material and chemical names, trade names, Chemical Abstracts Service (CAS) number, material supplier, and incoming material specifications

Material recycling (if applicable): describe the recycling process, and document evidence for coherent final device properties

Design and Manufacturing Process Considerations Nothing listed here depends on build methods

Design and Manufacturing Process Considerations Post-processing:

From cleaning to annealing for desired properties and Ra document all steps and include a discussion of the effects on the materials and device hard-to-reach spaces: effects assessment

Design and Manufacturing Process Considerations Process validation and acceptance activities:

Process validation: parameters, process steps, software document monitoring and control methods and dataEstablish criteria for determining successful final device

Revalidation: when changes in manufacturing process Acceptance activities: ASTM Committee F42 on AM tech. Test coupons: the worse-case for destructive tests

Design and Manufacturing Process Considerations Quality data:

Ensure the quality data (such as build volume location) can be analyzed enable proper identification of quality problems and investigation of the cause of nonconformities

Design and Manufacturing Process Considerations Device description Mechanical testing Dimensional measurements Material characterization Cleaning and sterilization Biocompatibility and Labeling

Device Testing Considerations

Device description: Dimensions, design variations, allowance, critical features, type of AM technology used (inc. a process flow chart)

Mechanical testing: Generally the same as that for a device manufactured by a traditional method+ consideration of build orientation and location


Dimensional measurements:Device dimensions may be affected by orientation and location of the build volume specify and measure

Material characterization: Material chemistry: e.g. chemical component Material physical properties: interlayer bonding, properties for

metal/ceramics, polymer, the absorbable


Cleaning and sterilization:Challenges posed by the complex geometries (consider in worse-case for destructive testing on final device)

Biocompatibility and Additional labeling ISO 10993 “Biological Evaluation of Medical Devices

Part 1: Evaluation and Testing” Labels of identification, and precaution is recommended

Comments?

FDA is open for comments and suggestions till August 8, 2016http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/3DPrintingofMedicalDevices/default.htm

http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/3DPrintingofMedicalDevices/default.htm




THANKS

Health & Medicine

Draft Guidance of 3D Printing Medical Devices issued by FDA on May 10, 2016