Printing 3D models of body parts is helping doctors get a better grip on surgical procedures.
THE video feed shows a brain surgery in progress. As an endoscope is inserted into the skull cavity and the onscreen image switches to the endoscope’s video feed, the fluid and tissue within becomes visible. As the surgeon cuts into the soft tissue, the view suddenly goes a cloudy red.
If this were a real surgery, it would have been a potentially serious problem as the surgeon may have cut into an artery, but in this case, it’s all a simulation, done on a realistic 3D printed model of a human head, complete with realistic fluid dynamics.
Once the realm of industrial prototyping and hobbyists, 3D printing is increasingly being used in the medical field to aid surgeons.
From scanning to printing
The Centre for Biomedical and Technology Integration (CBMTI), a commercial spinoff of University Malaya, is currently utilising 3D printers from Stratasys Ltd to produce lifelike multi-material “biomodels” to assist in surgical planning and training.
CBMTI, which was set up in 2012 with a startup grant from the university, is utilising data obtained from actual CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) scans of patients to recreate realistic 3D printed body parts.
These biomodels aren’t simply hard plastic 3D prints — using multi-material 3D printers from Stratasys, CBMTI has been able to recreate not just a realistic skull, for example, but also the soft brain matter and even tumours within the skull, as well as “skin” with realistic texture and elasticity.
With these models, the surgeon can drill “bone” and even use a scalpel to cut “skin” and it would feel just like the real thing, or at least close enough to it for training purposes.
“Before 3D printing came along, the only way we could provide doctors with a visual model was to use virtual reality, where we used the same CT and MRI data to create computer models,” said Yuwaraj Kumar Balakrishnan, operations manager of CBMTI.
The virtual reality models only exist in the computer and while an added level of realism could be attained by utilising 3D stereoscopy via 3D glasses (like the one in cinemas), the real problem was that doctors still could not touch and feel what they were looking at.
That all changed when 3D printers came along — now with 3D printing technology, that same data is used to produce a physical model that the doctor can hold in the hand, examine and even simulate an operation with, if needed.
While most models are “dry,” Yuwaraj says that the team have also created an even more realistic model incorporating fluid dynamics by adding tubes with liquid at various pressures to give surgeons a more accurate simulation when performing endoscopic neurosurgical procedures.
With a biomodel of a head with a brain tumour, for example, the surgeon using an endoscope would see a fairly accurate representation of what it looks like inside a human head.
Dr Vicknes Waran, professor and consultant neurosurgeon at University of Malaya, explains that the use of such a model is increasingly important as performing surgeries on live patients carries legal and ethical issues, while using cadavers is expensive and increasingly hard to come by.
With the two Stratasys 3D printers which CBMTI owns, namely the Connex500 and Objet Eden 350, the team of medical clinicians, rapid prototyping engineers, computer programmers and electrical engineers have been working to produce prototypes for university research, as well as custom titanium implants and biomodels for surgical training.
One notable example of the team’s work is producing a 3D printed model of a patient’s skull for Datuk Dr Zainal Ariff Abdul Rahman, professor at the department of Oro-Maxillofacial Surgical and Medical Sciences at the University.
For Dr Zainal, the CBMTI team were tasked with creating a 3D printed model of a young patient’s skull as well as skin with realistic elasticity for the purposes of pre-op planning.
“We had a three-year old patient with a craniofacial deformity that required us to perform extensive surgery, and the 3D printed skull and skin helped us to work out how to perform the surgery and gave us an idea whether the skin could be stretched as far as we wanted it to,” Dr Zainal said.
3D printing is an ever growing market for Stratasys, especially in the automobile industry and in the medical field.
According to Guy J. Ofek, Southeast Asia territory manager for Stratasys, the global 3D printing in medical applications market was valued at US$354.5mil (about RM1.13bil) in 2012, and is expected to grow at a compound annual growth rate (CAGR) of 15.4% from 2013 to 2019.
Ofek added that Stratasys sees a similar growth rate for 3D printing in the medical field locally as well.