3D Printing of Medical Devices
The Race for PPE—Meeting the Need With 3D Printing
As the world ushered in the 2020 new year, few could imagine the chaos of a global pandemic that lay ahead. While nations scrambled to mobilize both human and material resources to fight the new virus and care for the sick and dying, a frightening reality began to take shape.
According to the World Health Organization (WHO) there was not enough Personal Protective Equipment (PPE) to meet the sudden, heavy demand created by the Novel Coronavirus, referred to as COVID-19.[600] In fact, in one U.S. survey conducted in May 2020, 87% of nurses reported having to reuse single-use disposable masks or N95 respirators at work due to lack of available supplies.[7] Nearly 30% said they had been exposed to confirmed COVID patients without wearing the appropriate PPE. By the summer of 2020, some 340 nurses, doctors, physicians assistants, medical technicians, and other healthcare workers had died from Coronavirus in the U.S. alone.[7]
The stress put on healthcare workers and the healthcare system as a whole was staggering. A supply chain that could normally deliver PPE in a timely manner was disrupted dramatically by COVID-19 conditions. Transportation, trade restrictions, border controls, and quarantines greatly reduced the global ability to adequately manufacture and deliver much needed equipment during the pandemic.
The existing system of production, supply, and demand is based on private producers and suppliers. With the sudden, critical demand for medical equipment and protective gear, other avenues for production and distribution were necessary.
A Possible Solution
The world needed innovative solutions to meet the exploding demand for personal protective equipment. The 3D printing process [on a global scale] helped provide the necessary equipment to protect both first responders and the medical community from infection. Normally the 3D printing process takes time and is slow to produce certain specific objects. The 3D printers generally use fused deposition modeling (FDM). Governments appealed to both large and small businesses, colleges, medical manufacturers and others to help supply their nation’s need for quick and efficient manufacturing of PPE. Thousands answered the call.
Critical medical devices manufactured using 3D printing technology throughout the surging COVID pandemic included N95 masks, surgical masks, face shields, Controlled Air Purifying Respirator (CAPR’s) systems and High Efficiency Particulate Air (HEPA) masks, designed for use with a HEPA filter.
Other COVID PPE
Personal protective equipment (PPE) includes protective clothing, gowns, gloves, goggles and respirators. Each of these, help keep healthcare workers and first responders safe from the viral spread of COVID 19. PPE also helps protect patients during hospitalization, or while seeing a medical professional.[12]
FDA and NIH Guide for New Partners and Contributors
In response to the urgent need for COVID related materials including, Personal Protective Equipment the National Institutes for Health created guidelines for suppliers, manufacturers, and small businesses to ensure products met with federal guidelines for both safety and efficacy.[8]
Who is coordinating and overseeing the manufacture of 3D PPE?
Public/Private Partnership is created to collaborate on open-source medical products needed for COVID-19 protection.
Agencies involved in the manufacture, quality control, and oversight of 3D Manufacturing of Personal Protective Equipment include:
The Food and Drug Administration (FDA)—Facilitating the use of 3D printing for emergency use
The Veterans Health Administration (VA)—Responsible for “clinically reviewing” PPE to ensure industry standards for safety and quality are met
The National Institutes of Health (NIH)—NIH 3D Print Exchange shares design files necessary to create PPE
America Makes—An online repository for products and equipment for the protection of people
Individuals within this collaborative group continue to work together evaluating 3D printable parts for their safety and efficacy. The most useful designs for both patients and healthcare practitioners will be identified and utilized in response to the COVID pandemic.
3D Printing—What Exactly is It?
The 3D printing process is also known in the industry as “additive manufacturing” or “rapid prototyping”. 3D printers build specific objects by fabricating a fine layer of materials that bond together layer by layer. 3D objects are created with the use of computer modeling applications, or 3D scans of objects that already exist. This process allows for rapid production of objects on demand.[1]
3D Printing—How it Works
3D printing involves the basic fusion process of creating a three-dimensional object using successive layers of raw material. Each layer is attached to the previous one through a bonding process, creating the 3D object. 3D files, such as CAD (Computer Aided Drafting), or MRI (Magnetic Resonance Imaging) create the virtual “blueprint” necessary for printing.
The Most Common Process—Powder Bed Fusion
Powder Bed Fusion is the most common process used in the creation of 3D medical devices and involves several different types of materials. The process subjects very fine metal or plastic powder to a laser or electron beam that melts the particles together. Each layer adheres to the layer below it, permanently fusing the material creating the specified object.[4]
Benefits of 3D Printing
3D printing offers multiple benefits for the end user, with a multitude of applications. Medical devices, household items, automotive parts, and an array of intricate mechanisms are forged through layering technology.
Medical devices created using 3D technology include:
Orthopedic implants
Cranial implants
Surgical instruments
Dental crowns
Prosthetics[3]
3D Manufacturing—The Path to Production
Creating a 3D object using additive technology requires
Steps include:
Design—Digital models are used to create a workable design.
Software Workflow—A design is converted to a file that will be sent to a printer.
Material Controls—Procedures, requirements, and supplier agreements are checked for every batch of 3D objects created.
Printing—3D objects are printed based on files created for specific objects.
Post-Processing—3D objects may be trimmed, polished, cooled, sterilized, drilled or subjected to another process after printing.
Process Validation and Verification—3D printed objects may be tested for strength and size, (or another parameter) to ensure performance as intended.
Testing—Testing methods and results for 3D printed medical devices are submitted to the FDA to demonstrate safety and efficacy. 3D devices are generally subject to the same regulations as traditionally manufactured medical devices.[6]
The benefits of 3D printing, also referred to as “additive manufacturing” are many,
allowing for greater flexibility, the ability to manufacture many different parts without additional equipment or tools, and the process of creating patient specific devices that match anatomy specifically. 3D printing can be used to produce objects with very complex internal structures.
Regulatory Controls, 3D Printed Medical Devices
In general, the Food and Drug Administration’s Center for Devices and Radiological Health (CDRH) oversees companies that manufacture, repackage, relabel, or import medical devices in the United States. Regulations apply to both premarket and postmarket devices and 3D printed medical devices are no exception.[5]
At this time, many personalized medical devices can be created using 3D printing technology. Because of this, FDA regulation for medical devices and 3D manufacturing have become intertwined.[2]
The Origins of 3D Printing
The concept of 3D printing using layered technology to create 3D objects was first introduced in Japan nearly 40 years ago. Using photopolymers and rapid prototyping (RP) technology prototypes could be quickly produced for product development. By using a variety of materials including plastics, metals, ceramics and concrete, 3 dimensional objects can now be created.[9]
Additive manufacturing or 3D printing was largely established in the 1980’s. In the beginning, 3D printing was cost prohibitive, machines were large, and most small businesses could not afford the technology for start-up. In time however, cheaper, smaller, higher quality printers became available creating a quick, viable manufacturing method for lightweight applications. This opened a floodgate of possibilities for already established companies forced to import small parts as part of a larger assembled product and those engaging in new business manufacturing in the United States.[10]
Historical Support for 3D Printing
The FDA, along with former president, Barack Obama supported the use of 3D printing and technology through the formation of the National Additive Manufacturing Innovation Institute in 2012. The institute was designed to encourage the return of manufacturing of hard goods in the United States.
The additive manufacturing process is ideal for lightweight applications. PPE can be manufactured quickly and efficiently, reducing waste and saving precious resources. The additive manufacturing process is both cost and time efficient eliminating the overproduction of molds and cores.[2]
3D Printing Uses
3D printers are useful at creating medical devices that feature complex geometry. Patient specific medical devices including prosthetics, cranial plates, and hip joints are made using imaging information to match an individual’s unique anatomy.
Medical Devices for Emergency Use
Emergency use devices have been approved for use in the past, under specific circumstances. These may include use when there is a condition that is life threatening, when no other acceptable treatment is available, or when there is insufficient time to complete the usual FDA approval process.[3]
Emergency Use—Not the Final Solution
Currently the American Society for Testing and Materials (ASTM) International sets the standard for sterilization and cleanliness of PPE. While the agency provides free, ongoing public access to standards for cleanliness and sterilization of PPE, some issues involving risks of 3D printed protective gear exist.
While 3D printing has provided the ability to quickly and efficiently produce critically needed personal protective equipment during the pandemic, some technical challenges associated with the additive process remain.
While personal protective equipment (PPE) including clothing, gowns, gloves, face shields, goggles, face masks, and respirators are used to protect individuals from injury, infections or illness, technical challenges with 3D printed PPE exists. Simply put, 3D printed PPE does not provide the same barrier to fluids and air filtration as FDA approved surgical masks and N95 respirators. Air leakage during movement, such as talking, and too rigid mask framework creates risk for the end user. In some cases, 3D printed PPE may be too porous for adequate sterilization as well.[11]
Future of 3D PPE
Moving forward it is clear that further development of printing techniques, deeper exploration of bondable materials, and critical design changes may be necessary to overcome the limitations of current 3D manufactured personal protective equipment. There is no doubt however, in the critically important role 3D additive manufacturing played in the response to COVID in the past two years.
References
13D printing. 3D Printing. (n.d.). Retrieved January 27, 2022, from https://library.educause.edu/topics/infrastructure-and-research-technologies/3d-printing
2Additive manufacturing/3d printing. U.S. Consumer Product Safety Commission. (n.d.). Retrieved January 27, 2022, from https://www.cpsc.gov/Regulations-Laws--Standards/Voluntary-Standards/Additive-Manufacturing-3D-Printing
3Center for Devices and Radiological Health. (n.d.). 3D printers are used to manufacture a variety of medical devices. U.S. Food and Drug Administration. Retrieved January 27, 2022, from https://www.fda.gov/medical-devices/3d-printing-medical-devices/medical-applications-3d-printing
4Center for Devices and Radiological Health. (n.d.). 3D printing of Medical Devices. U.S. Food and Drug Administration. Retrieved January 27, 2022, from https://www.fda.gov/medical-devices/products-and-medical-procedures/3d-printing-medical-devices
5Center for Devices and Radiological Health. (n.d.). FDA's role in 3D printing. U.S. Food and Drug Administration. Retrieved January 27, 2022, from https://www.fda.gov/medical-devices/3d-printing-medical-devices/fdas-role-3d-printing
6Center for Devices and Radiological Health. (n.d.). There are multiple steps to printing a 3D device. the number of steps. U.S. Food and Drug Administration. Retrieved January 27, 2022, from https://www.fda.gov/medical-devices/3d-printing-medical-devices/process-3d-printing-medical-devices
7Cohen, J., & Rodgers, Y. van der M. (2020, December). Contributing factors to personal protective equipment shortages during the COVID-19 pandemic. Preventive medicine. Retrieved January 27, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7531934/
8Commissioner, O. of the. (n.d.). FDA, VA, NIH, and America makes covid-19 public-private partnership. U.S. Food and Drug Administration. Retrieved January 27, 2022, from https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/fda-efforts-connect-manufacturers-and-health-care-entities-fda-department-veterans-affairs-national
9Nicole.ausherman@nist.gov. (2021, July 13). How smaller manufacturers can take advantage of additive manufacturing. NIST. Retrieved January 27, 2022, from https://www.nist.gov/blogs/manufacturing-innovation-blog/how-smaller-manufacturers-can-take-advantage-additive
10Note - bu.edu. (n.d.). Retrieved January 27, 2022, from https://www.bu.edu/jostl/files/2016/08/NISSAN_NOTE_MACROD-PDF.pdf
11U.S. Department of Health and Human Services. (n.d.). 3D printing medical equipment in response to the COVID-19 pandemic. National Institutes of Health. Retrieved January 27, 2022, from https://www.nihlibrary.nih.gov/services/3d-printing-service/3d-printing-medical-equipment-response-covid-19-pandemic
12U.S. Department of Health and Human Services. (n.d.). Covid-19 response. National Institutes of Health. Retrieved January 27, 2022, from https://3dprint.nih.gov/collections/covid-19-response