medical 3D printing
Medical 3D printing is increasingly deployed in both clinical and research-based healthcare activities
What is medical 3D printing?
Medical 3D printing is increasingly deployed in both clinical and research-based healthcare activities. It involves the creation of physical replicas of anatomical structures using 3D printing (also known as additive manufacturing) processes. Then, a digital computer model is developed to describe the facilities to be printed. In contrast, patient-specific models for 3D printing are derived from 3D imaging processes such as MRI and X-Ray CT. Small (even single unit) batches can then be manufactured due to the flexibility, speed, and relatively low cost of the 3D printing process. The models themselves facilitate hospitals and other point-of-care (POC) organizations in planning surgeries and serve as an aid for teaching or explanation of complex medical concepts, for example, to a patient due to receive surgery.
What are the benefits of medical 3D printing?
The ability to visualize and explore complex anatomy as an actual three-dimensional object affords medical professionals the luxury of decision supports not previously available. In a clinical setting, the 3D printed models allow increased comprehension of anatomical and pathological structures. Models serve as convenient tools to trial the placement of implants and other medical devices and to envisage surgical activities. Advancements such as multi-color and multi-material printing can also help to stimulate better the surgical environment for pre-surgical planning and intra-operative reference. These models offer a dynamic complement to on-screen visualizations to build confidence in healthcare decisions.
For medical device manufacturers and research-based healthcare activities, medical 3D printing can provide an economic tool for progressing iterative design or process improvements due to its capacity for rapid prototyping. 3D printing also has the potential to provide an early means of validation of in silico trial outputs. With these tools, greater confidence can be gained in new developments before expensive physical testing or in vivo studies are deployed.
How does medical 3D printing work?
To develop a patient-specific 3D print, digitization of a patient’s fundamental anatomical structures must first occur. This method leverages 3D scanning techniques such as MRI, X-ray CT, or 3D ultrasound to produce a volumetric anatomy image. Next, the images must be labeled via a segmentation process to isolate structures of interest and develop a 3D computer model. The techniques are highly varied depending on the scanning modality, anatomical subject, and image quality. Traditional approaches require significant time and expertise, but programs with advanced segmentation capability such as Simpleware software can expedite this process.
The 3D models, which may be multi-part, are converted to a series of surface meshes and prepared for 3D printing by adding connectors and surface color information. The surfaces may also be partitioned to allow disassembly of the resulting print, making it easier to view pathologies or structures of interest. The surfaces are finally exported to the 3D printer, typically as STL files for interpretation by the printer software, which adds support material and calculates and executes the printer head paths needed to layer material and reproduce the computer model as a physical object.
Models have been used to examine liver tumors and potential radiation treatment methods. In addition, the 3D printed models provide an additional option for clinicians to understand patient anatomies before treatment better.
Biocompatible 3D Printable Materials
Most 3D printing processes may employ biocompatible polymers, elastomers, and metals for prototypes and practical products. Regarding complexity and personalization, 3D printing of biocompatible materials outperforms other production methods, which is critical for the medical business. An auditory aid that is widely accessible on the market, for example, may not comfortably match a specific ear. In such circumstances, it is now possible to custom print those based on the ear measurements.
Here are some examples of biocompatible materials used for 3D printing:
- Polyamide 12
- Silicone 30
- Cyanate Ester 221
- Epoxy 82
- Rigid Polyurethane 70
- FPU 50
- True Silicone
- ABS M30i
- PC ISO
- Polyetherimide 1010
- Stainless Steel
3D Printing of Surgical Instruments
3D printing’s rapidity, price, modifiability, and design flexibility have resulted in a wide range of application cases in the medical equipment business.
It not only means that an assortment of medical device components may be created on-demand and cheaply, but it also allows for speedier prototyping, more personalized, bespoke designs, and a more extensive range of materials to be employed when compared to traditional manufacturing processes such as injection molding.
Forceps, retractors, medical clamps, needle drivers, hemostats, and scalpel handles are just a few of the surgical equipment created with 3D printing technology.
Since these instruments are not as complicated — or intrusive in their function — as human organs, 3D printing of surgical equipment has substantially fewer legislative and practical restrictions. As a result, technology is already being employed far more broadly in the healthcare industry.
The main advantage of 3D printing in producing this equipment is that precise design alterations can be made, typically based on input from surgeons after they have used a prototype. Because of the speed with which designs may be modified and produced, changes can be made quickly, sometimes even on the same day.
Custom Made Prosthetics Using 3D Printing
Professionals have created 3D-printed tissue for burn sufferers, newborn airway splints, face reconstruction components for cancer patients, and orthopedic implants for the elderly. The rapidly evolving technology has produced more than 60 million personalized hearing-aid shells and ear molds. It is already manufacturing thousands of dental crowns and bridges from digital scans of teeth, replacing the centuries-old wax modeling processes.
Jaw and knee replacement surgeries are also commonly performed utilizing surgical guidelines printed on the equipment. So it’s no wonder that the innovation has sparked interest in the area of prosthetics, although inadvertently at times.
Surgery Preparation Assisted by the Use of 3D Printed Models
Fast expanding 3D printing technology has significantly improved how current surgeons circumvent any deficiencies during surgery. For starters, a volumetric dataset obtained by multi-detector computed tomography (MDCT) or MRI is transformed into a virtual 3D model that serves as a framework for 3D printing any physiological model of interest.
In addition to saving surgical setup time, 3D printed models provide physicians a unique sensory impression of the morphological features that would not be attainable until the surgical operation began.
Regulation of Medical 3D Printing
The FDA does not control 3D printers; instead, it governs the medical items created through 3D printing. The regulatory assessment required determines the type of product being manufactured, its intended use, and the possible dangers to patients. Devices, the most prevalent sort of 3D printed device at the moment, are controlled by the FDA’s Center for Devices and Radiological Health and fall into one of three categories.
The FDA categorizes devices according to their amount of threat and the regulatory measures required to offer reasonable assurance of safety and efficacy. Class I equipment, which includes bandages and portable surgical tools, is low risk. Class II devices, like infusion pumps, are considered moderately risky. In contrast, Class III devices that are exposed to high risks incorporate products that are life-supporting or life-sustaining, significantly critical in avoiding impairment of human health, or display an irrational potential for harm. A Class III device would involve a pacemaker.